v31.5.0

v31.5.0-rc.0
When merging release notes, allow considering later versions in the same release cycle (#4085 )
2024-03-12 18:33:38 +00:00 · 2024-03-05 14:03:49 +00:00 · 2024-03-05 09:34:09 +00:00 · 2024-02-29 12:20:53 +00:00 · 2024-02-27 12:51:20 +00:00 · 2024-02-27 12:51:18 +00:00
151 changed files with 79027 additions and 2847 deletions
@@ -1,8 +1,15 @@
-*                         @matrix-org/element-web
-/.github/workflows/**     @matrix-org/element-web-app-team
-/package.json             @matrix-org/element-web-app-team
-/yarn.lock                @matrix-org/element-web-app-team
+*                         @matrix-org/element-web-reviewers
+/.github/workflows/**     @matrix-org/element-web-team
+/package.json             @matrix-org/element-web-team
+/yarn.lock                @matrix-org/element-web-team
 /src/webrtc               @matrix-org/element-call-reviewers
 /src/matrixrtc               @matrix-org/element-call-reviewers
 /spec/*/webrtc            @matrix-org/element-call-reviewers
 /spec/*/matrixrtc            @matrix-org/element-call-reviewers
+
+/src/crypto               @matrix-org/element-crypto-web-reviewers
+/src/rust-crypto          @matrix-org/element-crypto-web-reviewers
+/spec/integ/crypto        @matrix-org/element-crypto-web-reviewers
+/spec/unit/crypto.spec.ts @matrix-org/element-crypto-web-reviewers
+/spec/unit/crypto         @matrix-org/element-crypto-web-reviewers
+/spec/unit/rust-crypto    @matrix-org/element-crypto-web-reviewers
@@ -5,9 +5,3 @@
 -   [ ] Tests written for new code (and old code if feasible)
 -   [ ] Linter and other CI checks pass
 -   [ ] Sign-off given on the changes (see [CONTRIBUTING.md](https://github.com/matrix-org/matrix-js-sdk/blob/develop/CONTRIBUTING.md))
-
-<!--
-If you would like to specify text for the changelog entry other than your PR title, add the following:
-
-Notes: Add super cool feature
-->
@@ -22,10 +22,14 @@ version-resolver:
 exclude-labels:
    - "T-Task"
    - "X-Reverted"
+    - "backport staging"
 exclude-contributors:
    - "RiotRobot"
 template: |
    $CHANGES
+#no-changes-template: ""
 prerelease: true
 prerelease-identifier: rc
 include-pre-releases: false
+stable-ref: master
+staging-ref: staging
@@ -11,13 +11,11 @@ jobs:
        if: github.event.workflow_run.conclusion == 'success' && github.event.workflow_run.event == 'pull_request'
        runs-on: ubuntu-latest
        steps:
-            # There's a 'download artifact' action, but it hasn't been updated for the workflow_run action
-            # (https://github.com/actions/download-artifact/issues/60) so instead we get this mess:
            - name: 📥 Download artifact
-              uses: dawidd6/action-download-artifact@246dbf436b23d7c49e21a7ab8204ca9ecd1fe615 # v2
+              uses: actions/download-artifact@v4
              with:
-                  workflow: static_analysis.yml
-                  run_id: ${{ github.event.workflow_run.id }}
+                  github-token: ${{ secrets.ELEMENT_BOT_TOKEN }}
+                  run-id: ${{ github.event.workflow_run.id }}
                  name: docs
                  path: docs

@@ -5,13 +5,9 @@ on:

    pull_request: {}

-    # For now at least, we don't run this or the cypress-tests against pushes
+    # For now at least, we don't run this or the downstream-end-to-end-tests against pushes
    # to develop or master.
    #
-    # Note that if we later choose to do so, we'll need to find a way to stop
-    # the results in Cypress Cloud from clobbering those from the 'develop'
-    # branch of matrix-react-sdk.
-    #
    #push:
    #    branches: [develop, master]
 concurrency:
@@ -20,7 +16,7 @@ concurrency:
 jobs:
    build-element-web:
        name: Build element-web
-        uses: matrix-org/matrix-react-sdk/.github/workflows/element-web.yaml@v3.85.0
+        uses: matrix-org/matrix-react-sdk/.github/workflows/element-web.yaml@v3.92.0
        with:
            matrix-js-sdk-sha: ${{ github.sha }}
            react-sdk-repository: matrix-org/matrix-react-sdk
@@ -1,5 +1,5 @@
 # Triggers after the "Downstream artifacts" build has finished, to run the
-# matrix-react-sdk playwright & cypress tests (with access to repo secrets)
+# matrix-react-sdk playwright tests (with access to repo secrets)

 name: matrix-react-sdk End to End Tests
 on:
@@ -13,28 +13,6 @@ concurrency:
    cancel-in-progress: ${{ github.event.workflow_run.event == 'pull_request' }}

 jobs:
-    cypress:
-        name: Cypress
-
-        # We only want to run the cypress tests on merge queue to prevent regressions
-        # from creeping in. They take a long time to run and consume multiple concurrent runners.
-        if: github.event.workflow_run.event == 'merge_group'
-
-        uses: matrix-org/matrix-react-sdk/.github/workflows/cypress.yaml@develop
-        permissions:
-            actions: read
-            issues: read
-            statuses: write
-            pull-requests: read
-        secrets:
-            # secrets are not automatically shared with called workflows, so share the cypress dashboard key, and the Kiwi login details
-            KNAPSACK_PRO_TEST_SUITE_TOKEN_CYPRESS_RUST: ${{ secrets.KNAPSACK_PRO_TEST_SUITE_TOKEN_CYPRESS_RUST}}
-            KNAPSACK_PRO_TEST_SUITE_TOKEN_CYPRESS_LEGACY: ${{ secrets.KNAPSACK_PRO_TEST_SUITE_TOKEN_CYPRESS_LEGACY}}
-            TCMS_USERNAME: ${{ secrets.TCMS_USERNAME }}
-            TCMS_PASSWORD: ${{ secrets.TCMS_PASSWORD }}
-        with:
-            react-sdk-repository: matrix-org/matrix-react-sdk
-
    playwright:
        name: Playwright
        # We only want to run the playwright tests on merge queue to prevent regressions
@@ -49,15 +27,17 @@ jobs:
            deployments: write
        with:
            react-sdk-repository: matrix-org/matrix-react-sdk
+        secrets:
+            ELEMENT_BOT_TOKEN: ${{ secrets.ELEMENT_BOT_TOKEN }}

-    # We want to make the cypress tests a required check for the merge queue.
+    # We want to make the Playwright tests a required check for the merge queue.
    #
-    # Unfortunately, github doesn't distinguish between "checks needed for branch
+    # Unfortunately, GitHub doesn't distinguish between "checks needed for branch
    # protection" (ie, the things that must pass before the PR will even be added
    # to the merge queue) and "checks needed in the merge queue". We just have to add
    # the check to the branch protection list.
    #
-    # Ergo, if we know we're not going to run the cypress tests, we need to add a
+    # Ergo, if we know we're not going to run the Playwright tests, we need to add a
    # passing status check manually.
    mark_skipped:
        if: github.event.workflow_run.event != 'merge_group'
@@ -65,18 +45,6 @@ jobs:
            statuses: write
        runs-on: ubuntu-latest
        steps:
-            - uses: Sibz/github-status-action@071b5370da85afbb16637d6eed8524a06bc2053e # v1
-              with:
-                  authToken: "${{ secrets.GITHUB_TOKEN }}"
-                  state: success
-                  description: Cypress skipped
-
-                  # Keep in step with the `context` that is updated by `Sibz/github-status-action`
-                  # in matrix-org/matrix-react-sdk/.github/workflows/cypress.yaml.
-                  context: "${{ github.workflow }} / cypress"
-
-                  sha: "${{ github.event.workflow_run.head_sha }}"
-
            - uses: Sibz/github-status-action@071b5370da85afbb16637d6eed8524a06bc2053e # v1
              with:
                  authToken: "${{ secrets.GITHUB_TOKEN }}"
@@ -20,7 +20,7 @@ jobs:
        runs-on: ubuntu-latest
        steps:
            - name: Notify matrix-react-sdk repo that a new SDK build is on develop so it can CI against it
-              uses: peter-evans/repository-dispatch@bf47d102fdb849e755b0b0023ea3e81a44b6f570 # v2
+              uses: peter-evans/repository-dispatch@ff45666b9427631e3450c54a1bcbee4d9ff4d7c0 # v3
              with:
                  token: ${{ secrets.ELEMENT_BOT_TOKEN }}
                  repository: ${{ matrix.repo }}
@@ -14,11 +14,18 @@ jobs:
        name: Preview Changelog
        runs-on: ubuntu-latest
        steps:
-            - uses: matrix-org/allchange@main
+            - uses: mheap/github-action-required-labels@80a96a4863886addcbc9f681b5b295ba7f5424e1 # v5
              if: github.event_name != 'merge_group'
              with:
-                  ghToken: ${{ secrets.GITHUB_TOKEN }}
-                  requireLabel: true
+                  labels: |
+                      X-Breaking-Change
+                      T-Deprecation
+                      T-Enhancement
+                      T-Defect
+                      T-Task
+                      Dependencies
+                  mode: minimum
+                  count: 1

    prevent-blocked:
        name: Prevent Blocked
@@ -39,6 +46,7 @@ jobs:
        if: github.event.action == 'opened'
        steps:
            - name: Check membership
+              if: github.event.pull_request.user.login != 'renovate[bot]'
              uses: tspascoal/get-user-teams-membership@ba78054988f58bea69b7c6136d563236f8ed2fc0 # v3
              id: teams
              with:
@@ -48,7 +56,7 @@ jobs:
                  GITHUB_TOKEN: ${{ secrets.ELEMENT_BOT_TOKEN }}

            - name: Add label
-              if: ${{ steps.teams.outputs.isTeamMember == 'false' }}
+              if: steps.teams.outputs.isTeamMember == 'false'
              uses: actions/github-script@v7
              with:
                  script: |
@@ -0,0 +1,88 @@
+name: Release Drafter
+on:
+    workflow_call:
+        inputs:
+            include-changes:
+                description: Project to include changelog entries from in this release.
+                type: string
+                required: false
+concurrency: release-drafter-action
+jobs:
+    draft:
+        runs-on: ubuntu-latest
+        steps:
+            - name: 🧮 Checkout code
+              uses: actions/checkout@v4
+              with:
+                  ref: staging
+                  fetch-depth: 0
+
+            - uses: actions/setup-node@v4
+              with:
+                  node-version-file: package.json
+                  cache: "yarn"
+
+            - name: Install Deps
+              run: "yarn install --frozen-lockfile"
+
+            - uses: t3chguy/release-drafter@105e541c2c3d857f032bd522c0764694758fabad
+              id: draft-release
+              env:
+                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+              with:
+                  disable-autolabeler: true
+
+            - name: Get actions scripts
+              uses: actions/checkout@v4
+              with:
+                  repository: matrix-org/matrix-js-sdk
+                  persist-credentials: false
+                  path: .action-repo
+                  sparse-checkout: |
+                      .github/actions
+                      scripts/release
+
+            - name: Ingest upstream changes
+              if: inputs.include-changes
+              uses: actions/github-script@v7
+              env:
+                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+                  RELEASE_ID: ${{ steps.draft-release.outputs.id }}
+                  DEPENDENCY: ${{ inputs.include-changes }}
+                  VERSION: ${{ steps.draft-release.outputs.tag_name }}
+              with:
+                  retries: 3
+                  script: |
+                      const { RELEASE_ID: releaseId, DEPENDENCY, VERSION } = process.env;
+                      const { owner, repo } = context.repo;
+                      const script = require("./.action-repo/scripts/release/merge-release-notes.js");
+
+                      let deps = [];
+                      if (DEPENDENCY.includes("/")) {
+                          deps.push(DEPENDENCY.replace("$VERSION", VERSION))
+                      } else {
+                          const fromVersion = JSON.parse((await github.request(`https://raw.githubusercontent.com/${owner}/${repo}/master/package.json`)).data).dependencies[DEPENDENCY];
+                          const toVersion = require("./package.json").dependencies[DEPENDENCY];
+
+                          if (toVersion.endsWith("#develop")) {
+                              core.warning(`${DEPENDENCY} will be kept at ${fromVersion}`, { title: "Develop dependency found" });
+                          } else {
+                              deps.push([DEPENDENCY, fromVersion, toVersion]);
+                          }
+                      }
+
+                      if (deps.length) {
+                          const notes = await script({
+                              github,
+                              releaseId,
+                              dependencies: deps,
+                          });
+
+                          await github.rest.repos.updateRelease({
+                              owner,
+                              repo,
+                              release_id: releaseId,
+                              body: notes,
+                              tag_name: VERSION,
+                          });
+                      }
@@ -2,20 +2,8 @@ name: Release Drafter
 on:
    push:
        branches: [staging]
-    workflow_dispatch:
-        inputs:
-            previous-version:
-                description: What release to use as a base for release note purposes
-                required: false
-                type: string
+    workflow_dispatch: {}
 concurrency: ${{ github.workflow }}
 jobs:
    draft:
-        runs-on: ubuntu-latest
-        steps:
-            - uses: release-drafter/release-drafter@e64b19c4c46173209ed9f2e5a2f4ca7de89a0e86 # v5
-              env:
-                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-              with:
-                  disable-autolabeler: true
-                  previous-version: ${{ inputs.previous-version }}
+        uses: matrix-org/matrix-js-sdk/.github/workflows/release-drafter-workflow.yml@develop
@@ -20,10 +20,8 @@ on:
                description: Publish to npm
                type: boolean
                default: false
-            dependencies:
-                description: |
-                    List of dependencies to update in `npm-dep=version` format.
-                    `version` can be `"current"` to leave it at the current version.
+            downstreams:
+                description: List of github projects (owner/repo) which should have their dependency bumped to the newly released version (in JSON string array string syntax)
                type: string
                required: false
            include-changes:
@@ -53,14 +51,14 @@ jobs:
            - name: Load GPG key
              id: gpg
              if: inputs.gpg-fingerprint
-              uses: crazy-max/ghaction-import-gpg@82a020f1f7f605c65dd2449b392a52c3fcfef7ef # v6
+              uses: crazy-max/ghaction-import-gpg@01dd5d3ca463c7f10f7f4f7b4f177225ac661ee4 # v6
              with:
                  gpg_private_key: ${{ secrets.GPG_PRIVATE_KEY }}
                  passphrase: ${{ secrets.GPG_PASSPHRASE }}
                  fingerprint: ${{ inputs.gpg-fingerprint }}

            - name: Get draft release
-              id: release
+              id: draft-release
              uses: cardinalby/git-get-release-action@cedef2faf69cb7c55b285bad07688d04430b7ada # v1
              env:
                  GITHUB_TOKEN: ${{ github.token }}
@@ -88,18 +86,12 @@ jobs:
              id: prepare
              run: |
                  echo "VERSION=$VERSION" >> $GITHUB_ENV
-                  {
-                      echo "RELEASE_NOTES<<EOF"
-                      echo "$BODY"
-                      echo "EOF"
-                  } >> $GITHUB_ENV

                  HAS_DIST=0
                  jq -e .scripts.dist package.json >/dev/null 2>&1 && HAS_DIST=1
                  echo "has-dist-script=$HAS_DIST" >> $GITHUB_OUTPUT
              env:
-                  BODY: ${{ steps.release.outputs.body }}
-                  VERSION: ${{ steps.release.outputs.tag_name }}
+                  VERSION: ${{ steps.draft-release.outputs.tag_name }}

            - name: Finalise version
              if: inputs.final
@@ -132,76 +124,23 @@ jobs:
            - name: Install dependencies
              run: "yarn install --frozen-lockfile"

-            - name: Update dependencies
-              id: update-dependencies
-              if: inputs.dependencies
-              run: |
-                  UPDATED=()
-                  while IFS= read -r DEPENDENCY; do
-                      [ -z "$DEPENDENCY" ] && continue
-                      IFS="=" read -r PACKAGE UPDATE_VERSION <<< "$DEPENDENCY"
-
-                      CURRENT_VERSION=$(cat package.json | jq -r .dependencies[\"$PACKAGE\"])
-                      echo "Current $PACKAGE version is $CURRENT_VERSION"
-
-                      if [ "$CURRENT_VERSION" == "null" ]
-                      then
-                          echo "Unable to find $PACKAGE in package.json"
-                          exit 1
-                      fi
-
-                      if [ "$UPDATE_VERSION" == "current" ] || [ "$UPDATE_VERSION" == "$CURRENT_VERSION" ]
-                      then
-                          echo "Not updating dependency $PACKAGE"
-                          continue
-                      fi
-
-                      echo "Upgrading $PACKAGE to $UPDATE_VERSION..."
-                      yarn upgrade "$PACKAGE@$UPDATE_VERSION" --exact
-                      git add -u
-                      git commit -m "Upgrade $PACKAGE to $UPDATE_VERSION"
-                      UPDATED+=("$PACKAGE")
-                  done <<< "$DEPENDENCIES"
-
-                  JSON=$(jq --compact-output --null-input '$ARGS.positional' --args -- "${UPDATED[@]}")
-                  echo "updated=$JSON" >> $GITHUB_OUTPUT
-              env:
-                  DEPENDENCIES: ${{ inputs.dependencies }}
-
-            - name: Prevent develop dependencies
-              if: inputs.dependencies
+            - name: Handle develop dependencies
              run: |
                  ret=0
-                  cat package.json | jq '.dependencies[]' | grep -q '#develop' || ret=$?
-                  if [ "$ret" -eq 0 ]; then
-                      echo "package.json contains develop dependencies. Refusing to release."
-                      exit
-                  fi
+                  cat package.json | jq -r '.dependencies | to_entries | .[] | "\(.key) \(.value)"' | grep '#develop$' | while read -r dep ; do
+                      IFS=" "
+                      PACKAGE=${dep[0]}
+                      VERSION=${dep[1]}
+
+                      echo "::warning title=Develop dependency found::$DEPENDENCY will be kept at $VERSION"
+                      yarn upgrade "$PACKAGE@$VERSION" --exact
+                      git add -u
+                      git commit -m "Keep $PACKAGE at $VERSION"
+                  done

            - name: Bump package.json version
              run: yarn version --no-git-tag-version --new-version "${VERSION#v}"

-            - name: Ingest upstream changes
-              if: |
-                  inputs.include-changes &&
-                  (!inputs.dependencies || contains(fromJSON(steps.update-dependencies.outputs.updated), inputs.include-changes))
-              uses: actions/github-script@v7
-              env:
-                  RELEASE_ID: ${{ steps.release.outputs.id }}
-                  DEPENDENCY: ${{ inputs.include-changes }}
-              with:
-                  retries: 3
-                  script: |
-                      const { RELEASE_ID: releaseId, DEPENDENCY, VERSION } = process.env;
-                      const { owner, repo } = context.repo;
-                      const script = require("./.action-repo/scripts/release/merge-release-notes.js");
-                      const notes = await script({
-                          github,
-                          releaseId,
-                          dependencies: [DEPENDENCY.replace("$VERSION", VERSION)],
-                      });
-                      core.exportVariable("RELEASE_NOTES", notes);
-
            - name: Add to CHANGELOG.md
              if: inputs.final
              run: |
@@ -219,6 +158,8 @@ jobs:
                  cat CHANGELOG.md.old >> CHANGELOG.md
                  rm CHANGELOG.md.old
                  git add CHANGELOG.md
+              env:
+                  RELEASE_NOTES: ${{ steps.draft-release.outputs.body }}

            - name: Run pre-release script to update package.json fields
              run: |
@@ -237,7 +178,7 @@ jobs:
              uses: ./.action-repo/.github/actions/upload-release-assets
              with:
                  gpg-fingerprint: ${{ inputs.gpg-fingerprint }}
-                  upload-url: ${{ steps.release.outputs.upload_url }}
+                  upload-url: ${{ steps.draft-release.outputs.upload_url }}
                  asset-path: ${{ inputs.asset-path }}

            - name: Create signed tag
@@ -252,7 +193,7 @@ jobs:
              uses: ./.action-repo/.github/actions/sign-release-tarball
              with:
                  gpg-fingerprint: ${{ inputs.gpg-fingerprint }}
-                  upload-url: ${{ steps.release.outputs.upload_url }}
+                  upload-url: ${{ steps.draft-release.outputs.upload_url }}

            # We defer pushing changes until after the release assets are built,
            # signed & uploaded to improve the atomicity of this action.
@@ -273,7 +214,7 @@ jobs:
              if: inputs.expected-asset-count
              uses: actions/github-script@v7
              env:
-                  RELEASE_ID: ${{ steps.release.outputs.id }}
+                  RELEASE_ID: ${{ steps.draft-release.outputs.id }}
                  EXPECTED_ASSET_COUNT: ${{ inputs.expected-asset-count }}
              with:
                  retries: 3
@@ -301,7 +242,7 @@ jobs:
            - name: Publish release
              uses: actions/github-script@v7
              env:
-                  RELEASE_ID: ${{ steps.release.outputs.id }}
+                  RELEASE_ID: ${{ steps.draft-release.outputs.id }}
                  FINAL: ${{ inputs.final }}
              with:
                  retries: 3
@@ -335,15 +276,16 @@ jobs:
        secrets:
            NPM_TOKEN: ${{ secrets.NPM_TOKEN }}

-    update-labels:
-        name: Advance release blocker labels
+    post-release:
+        name: Post release steps
        needs: release
        runs-on: ubuntu-latest
        steps:
            - id: repository
              run: echo "REPO=${GITHUB_REPOSITORY#*/}" >> $GITHUB_OUTPUT

-            - uses: garganshu/github-label-updater@3770d15ebfed2fe2cb06a241047bc340f774a7d1 # v1.0.0
+            - name: Advance release blocker labels
+              uses: garganshu/github-label-updater@3770d15ebfed2fe2cb06a241047bc340f774a7d1 # v1.0.0
              with:
                  owner: ${{ github.repository_owner }}
                  repo: ${{ steps.repository.outputs.REPO }}
@@ -351,3 +293,39 @@ jobs:
                  filter-labels: X-Upcoming-Release-Blocker
                  remove-labels: X-Upcoming-Release-Blocker
                  add-labels: X-Release-Blocker
+
+            - name: Wait for master->develop gitflow merge
+              if: inputs.final
+              uses: t3chguy/wait-on-check-action@18541021811b56544d90e0f073401c2b99e249d6 # fork
+              with:
+                  ref: master
+                  repo-token: ${{ secrets.GITHUB_TOKEN }}
+                  wait-interval: 10
+                  check-name: merge
+                  allowed-conclusions: success
+
+    bump-downstreams:
+        name: Update npm dependency in downstream projects
+        needs: npm
+        runs-on: ubuntu-latest
+        if: inputs.downstreams
+        strategy:
+            matrix:
+                repo: ${{ fromJSON(inputs.downstreams) }}
+        steps:
+            - uses: actions/checkout@v4
+              with:
+                  repository: ${{ matrix.repo }}
+                  ref: staging
+                  token: ${{ secrets.ELEMENT_BOT_TOKEN }}
+
+            - name: Bump dependency
+              env:
+                  DEPENDENCY: ${{ needs.npm.outputs.id }}
+              run: |
+                  git config --global user.email "releases@riot.im"
+                  git config --global user.name "RiotRobot"
+                  yarn upgrade "$DEPENDENCY" --exact
+                  git add package.json yarn.lock
+                  git commit -am"Upgrade dependency to $DEPENDENCY"
+                  git push origin staging
@@ -4,10 +4,16 @@ on:
        secrets:
            NPM_TOKEN:
                required: true
+        outputs:
+            id:
+                description: "The npm package@version string we published"
+                value: ${{ jobs.npm.outputs.id }}
 jobs:
    npm:
        name: Publish to npm
        runs-on: ubuntu-latest
+        outputs:
+            id: ${{ steps.npm-publish.outputs.id }}
        steps:
            - name: 🧮 Checkout code
              uses: actions/checkout@v4
@@ -28,6 +28,7 @@ jobs:
        with:
            final: ${{ inputs.mode == 'final' }}
            npm: ${{ inputs.npm }}
+            downstreams: '["matrix-org/matrix-react-sdk", "element-hq/element-web"]'

    docs:
        name: Publish Documentation
@@ -62,6 +63,7 @@ jobs:
                  yarn tpv purge --yes --out _docs --stale --major 10
                  yarn gendoc
                  symlinks -rc _docs
+                  find _docs -xtype l -delete

            - name: 🔨 Set up git
              run: |
@@ -5,7 +5,13 @@ on:
        secrets:
            SONAR_TOKEN:
                required: true
+            ELEMENT_BOT_TOKEN:
+                required: true
        inputs:
+            sharded:
+                type: boolean
+                required: false
+                description: "Whether to combine multiple LCOV and jest-sonar-report files in coverage artifact"
            extra_args:
                type: string
                required: false
@@ -13,10 +19,12 @@ on:
 jobs:
    sonarqube:
        runs-on: ubuntu-latest
-        if: github.event.workflow_run.conclusion == 'success'
+        if: |
+            github.event.workflow_run.conclusion == 'success' &&
+            github.event.workflow_run.event != 'merge_group'
        steps:
            # We create the status here and then update it to success/failure in the `report` stage
-            # This provides an easy link to this workflow_run from the PR before Cypress is done.
+            # This provides an easy link to this workflow_run from the PR before Sonarcloud is done.
            - uses: Sibz/github-status-action@071b5370da85afbb16637d6eed8524a06bc2053e # v1
              with:
                  authToken: ${{ secrets.GITHUB_TOKEN }}
@@ -25,22 +33,55 @@ jobs:
                  sha: ${{ github.event.workflow_run.head_sha }}
                  target_url: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}

+            - name: "🧮 Checkout code"
+              uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
+              with:
+                  repository: ${{ github.event.workflow_run.head_repository.full_name }}
+                  ref: ${{ github.event.workflow_run.head_branch }} # checkout commit that triggered this workflow
+                  fetch-depth: 0 # Shallow clones should be disabled for a better relevancy of analysis
+
+            - name: 📥 Download artifact
+              uses: actions/download-artifact@v4
+              if: ${{ !inputs.sharded }}
+              with:
+                  github-token: ${{ secrets.ELEMENT_BOT_TOKEN }}
+                  run-id: ${{ github.event.workflow_run.id }}
+                  name: coverage
+                  path: coverage
+            - name: 📥 Download sharded artifacts
+              uses: actions/download-artifact@v4
+              if: inputs.sharded
+              with:
+                  github-token: ${{ secrets.ELEMENT_BOT_TOKEN }}
+                  run-id: ${{ github.event.workflow_run.id }}
+                  pattern: coverage-*
+                  path: coverage
+                  merge-multiple: true
+
+            - id: extra_args
+              run: |
+                  coverage=$(find coverage -type f -name '*lcov.info' | tr '\n' ',' | sed 's/,$//g')
+                  echo "reportPaths=$coverage" >> $GITHUB_OUTPUT
+                  reports=$(find coverage -type f -name 'jest-sonar-report*.xml' | tr '\n' ',' | sed 's/,$//g')
+                  echo "testExecutionReportPaths=$reports" >> $GITHUB_OUTPUT
+
            - name: "🩻 SonarCloud Scan"
              id: sonarcloud
              uses: matrix-org/sonarcloud-workflow-action@v2.7
              # workflow_run fails report against the develop commit always, we don't want that for PRs
              continue-on-error: ${{ github.event.workflow_run.head_branch != 'develop' }}
              with:
+                  skip_checkout: true
                  repository: ${{ github.event.workflow_run.head_repository.full_name }}
                  is_pr: ${{ github.event.workflow_run.event == 'pull_request' }}
                  version_cmd: "cat package.json | jq -r .version"
                  branch: ${{ github.event.workflow_run.head_branch }}
                  revision: ${{ github.event.workflow_run.head_sha }}
                  token: ${{ secrets.SONAR_TOKEN }}
-                  coverage_run_id: ${{ github.event.workflow_run.id }}
-                  coverage_workflow_name: tests.yml
-                  coverage_extract_path: coverage
-                  extra_args: ${{ inputs.extra_args }}
+                  extra_args: |
+                      ${{ inputs.extra_args }}
+                      -Dsonar.javascript.lcov.reportPaths=${{ steps.extra_args.outputs.reportPaths }}
+                      -Dsonar.testExecutionReportPaths=${{ steps.extra_args.outputs.testExecutionReportPaths }}

            - uses: Sibz/github-status-action@071b5370da85afbb16637d6eed8524a06bc2053e # v1
              if: always()
@@ -8,38 +8,12 @@ concurrency:
    group: ${{ github.workflow }}-${{ github.event.workflow_run.head_branch }}
    cancel-in-progress: true
 jobs:
-    # This is a workaround for https://github.com/SonarSource/SonarJS/issues/578
-    prepare:
-        name: Prepare
-        if: github.event.workflow_run.conclusion == 'success' && github.event.workflow_run.event != 'merge_group'
-        runs-on: ubuntu-latest
-        outputs:
-            reportPaths: ${{ steps.extra_args.outputs.reportPaths }}
-            testExecutionReportPaths: ${{ steps.extra_args.outputs.testExecutionReportPaths }}
-        steps:
-            # There's a 'download artifact' action, but it hasn't been updated for the workflow_run action
-            # (https://github.com/actions/download-artifact/issues/60) so instead we get this mess:
-            - name: 📥 Download artifact
-              uses: dawidd6/action-download-artifact@246dbf436b23d7c49e21a7ab8204ca9ecd1fe615 # v2
-              with:
-                  workflow: tests.yaml
-                  run_id: ${{ github.event.workflow_run.id }}
-                  name: coverage
-                  path: coverage
-
-            - id: extra_args
-              run: |
-                  coverage=$(find coverage -type f -name '*lcov.info' | tr '\n' ',' | sed 's/,$//g')
-                  echo "reportPaths=$coverage" >> $GITHUB_OUTPUT
-                  reports=$(find coverage -type f -name 'jest-sonar-report*.xml' | tr '\n' ',' | sed 's/,$//g')
-                  echo "testExecutionReportPaths=$reports" >> $GITHUB_OUTPUT
-
    sonarqube:
        name: 🩻 SonarQube
        if: github.event.workflow_run.conclusion == 'success' && github.event.workflow_run.event != 'merge_group'
-        needs: prepare
        uses: matrix-org/matrix-js-sdk/.github/workflows/sonarcloud.yml@develop
        secrets:
            SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
+            ELEMENT_BOT_TOKEN: ${{ secrets.ELEMENT_BOT_TOKEN }}
        with:
-            extra_args: -Dsonar.javascript.lcov.reportPaths=${{ needs.prepare.outputs.reportPaths }} -Dsonar.testExecutionReportPaths=${{ needs.prepare.outputs.testExecutionReportPaths }}
+            sharded: true
@@ -91,7 +91,7 @@ jobs:
                  find _docs -mindepth 1 -maxdepth 1 -type d -execdir mv {} stable \; -quit

            - name: Upload Artifact
-              uses: actions/upload-artifact@v3
+              uses: actions/upload-artifact@v4
              with:
                  name: docs
                  path: _docs
@@ -52,13 +52,13 @@ jobs:

            - name: Move coverage files into place
              if: env.ENABLE_COVERAGE == 'true'
-              run: mv coverage/lcov.info coverage/${{ steps.setupNode.output.node-version }}-${{ matrix.specs }}.lcov.info
+              run: mv coverage/lcov.info coverage/${{ steps.setupNode.outputs.node-version }}-${{ matrix.specs }}.lcov.info

            - name: Upload Artifact
              if: env.ENABLE_COVERAGE == 'true'
-              uses: actions/upload-artifact@v3
+              uses: actions/upload-artifact@v4
              with:
-                  name: coverage
+                  name: coverage-${{ matrix.specs }}-${{ matrix.node == 'lts/*' && 'lts' || matrix.node }}
                  path: |
                      coverage
                      !coverage/lcov-report
@@ -0,0 +1,14 @@
+name: Move new issues into Issue triage board
+
+on:
+    issues:
+        types: [opened]
+
+jobs:
+    automate-project-columns-next:
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/add-to-project@main
+              with:
+                  project-url: https://github.com/orgs/element-hq/projects/120
+                  github-token: ${{ secrets.ELEMENT_BOT_TOKEN }}
@@ -1,4 +1,3 @@
 #!/usr/bin/env sh
-. "$(dirname "$0")/_/husky.sh"

 npx lint-staged
@@ -25,5 +25,6 @@ out
 # This file is owned, parsed, and generated by allchange, which doesn't comply with prettier
 /CHANGELOG.md

-# This file is also autogenerated
+# These files are also autogenerated
 /spec/test-utils/test-data/index.ts
+/spec/test-utils/test_indexeddb_cryptostore_dump/dump.json
@@ -1,3 +1,108 @@
+Changes in [31.5.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v31.5.0) (2024-03-12)
+==================================================================================================
+## ✨ Features
+
+* Update MSC2965 OIDC Discovery implementation ([#4064](https://github.com/matrix-org/matrix-js-sdk/pull/4064)). Contributed by @t3chguy.
+
+## 🐛 Bug Fixes
+
+* Add basic retry for rust crypto outgoing requests ([#4061](https://github.com/matrix-org/matrix-js-sdk/pull/4061)). Contributed by @BillCarsonFr.
+
+
+Changes in [31.4.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v31.4.0) (2024-02-27)
+==================================================================================================
+## ✨ Features
+
+* Validate `account_management_uri` and `account_management_actions_supported` from OIDC Issuer well-known ([#4074](https://github.com/matrix-org/matrix-js-sdk/pull/4074)). Contributed by @t3chguy.
+* Allow specifying OIDC url state parameter for passing data to callback ([#4068](https://github.com/matrix-org/matrix-js-sdk/pull/4068)). Contributed by @t3chguy.
+* Add getAuthIssuer method for MSC2965 ([#4071](https://github.com/matrix-org/matrix-js-sdk/pull/4071)). Contributed by @t3chguy.
+* Allow specifying more OIDC client metadata for dynamic registration ([#4070](https://github.com/matrix-org/matrix-js-sdk/pull/4070)). Contributed by @t3chguy.
+* Add unread marker event type ([#4069](https://github.com/matrix-org/matrix-js-sdk/pull/4069)). Contributed by @dbkr.
+* Add "AsJson" forms of the key import/export methods ([#4057](https://github.com/matrix-org/matrix-js-sdk/pull/4057)). Contributed by @andybalaam.
+
+## 🐛 Bug Fixes
+
+* Ignore memberships of users that are not in the call ([#4065](https://github.com/matrix-org/matrix-js-sdk/pull/4065)). Contributed by @toger5.
+* Await encrypted messages ([#4063](https://github.com/matrix-org/matrix-js-sdk/pull/4063)). Contributed by @toger5.
+* ElementR | Ensure own user and device trust are updated after migration before giving back control to the app. ([#4059](https://github.com/matrix-org/matrix-js-sdk/pull/4059)). Contributed by @BillCarsonFr.
+* Bump matrix-sdk-crypto-wasm to 4.5.0 ([#4060](https://github.com/matrix-org/matrix-js-sdk/pull/4060)). Contributed by @andybalaam.
+
+
+Changes in [31.3.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v31.3.0) (2024-02-13)
+==================================================================================================
+## ✨ Features
+
+* Add expire\_ts compatibility to matrixRTC ([#4032](https://github.com/matrix-org/matrix-js-sdk/pull/4032)). Contributed by @toger5.
+* Element-R: support for migration of the room list from legacy crypto ([#4036](https://github.com/matrix-org/matrix-js-sdk/pull/4036)). Contributed by @richvdh.
+* Element-R: check persistent room list for encryption config ([#4035](https://github.com/matrix-org/matrix-js-sdk/pull/4035)). Contributed by @richvdh.
+* Support optional MSC3860 redirects ([#4007](https://github.com/matrix-org/matrix-js-sdk/pull/4007)). Contributed by @turt2live.
+
+## 🐛 Bug Fixes
+
+* WebR: migrate the megolm session imported flag ([#4037](https://github.com/matrix-org/matrix-js-sdk/pull/4037)). Contributed by @BillCarsonFr.
+* ElementR: fix emoji verification stalling when both ends hit start at the same time ([#4004](https://github.com/matrix-org/matrix-js-sdk/pull/4004)). Contributed by @uhoreg.
+* Dependencies: Bump wasm bindings version to 4.3.0 ([#4042](https://github.com/matrix-org/matrix-js-sdk/pull/4042)). Contributed by @BillCarsonFr.
+* Element R: emit events when devices have changed ([#4019](https://github.com/matrix-org/matrix-js-sdk/pull/4019)). Contributed by @uhoreg.
+* ElementR: report invalid keys rather than failing to restore from backup ([#4006](https://github.com/matrix-org/matrix-js-sdk/pull/4006)). Contributed by @uhoreg.
+* Make `timeline` a getter ([#4022](https://github.com/matrix-org/matrix-js-sdk/pull/4022)). Contributed by @florianduros.
+* Implement getting verification cancellation info in Rust crypto ([#3947](https://github.com/matrix-org/matrix-js-sdk/pull/3947)). Contributed by @uhoreg.
+* Fix crypto migration for megolm sessions with no sender key ([#4024](https://github.com/matrix-org/matrix-js-sdk/pull/4024)). Contributed by @richvdh.
+
+
+Changes in [31.2.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v31.2.0) (2024-01-31)
+==================================================================================================
+## ✨ Features
+
+* Emit events during migration from libolm ([#3982](https://github.com/matrix-org/matrix-js-sdk/pull/3982)). Contributed by @richvdh.
+* Support for migration from from libolm ([#3978](https://github.com/matrix-org/matrix-js-sdk/pull/3978)). Contributed by @richvdh.
+
+## 🐛 Bug Fixes
+
+* ElementR | backup: call expensive `roomKeyCounts` less often ([#4015](https://github.com/matrix-org/matrix-js-sdk/pull/4015)). Contributed by @BillCarsonFr.
+* Decrypt and Import full backups in chunk with progress ([#4005](https://github.com/matrix-org/matrix-js-sdk/pull/4005)). Contributed by @BillCarsonFr.
+* Fix new threads not appearing. ([#4009](https://github.com/matrix-org/matrix-js-sdk/pull/4009)). Contributed by @dbkr.
+
+
+Changes in [31.1.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v31.1.0) (2024-01-19)
+==================================================================================================
+## ✨ Features
+
+* Broaden spec version support ([#4016](https://github.com/matrix-org/matrix-js-sdk/pull/4016)). Contributed by @RiotRobot.
+
+
+Changes in [31.0.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v31.0.0) (2024-01-16)
+==================================================================================================
+## 🚨 BREAKING CHANGES
+
+* Bump minimum spec version to v1.5 ([#3970](https://github.com/matrix-org/matrix-js-sdk/pull/3970)). Contributed by @richvdh.
+
+## ✨ Features
+
+* Bump minimum spec version to v1.5 ([#3970](https://github.com/matrix-org/matrix-js-sdk/pull/3970)). Contributed by @richvdh.
+* Send authenticated /versions request ([#3968](https://github.com/matrix-org/matrix-js-sdk/pull/3968)). Contributed by @dbkr.
+
+## 🐛 Bug Fixes
+
+* Revert "Bump matrix-sdk-crypto-wasm to 3.6.0" ([#3991](https://github.com/matrix-org/matrix-js-sdk/pull/3991)). Contributed by @andybalaam.
+* #22606 Fix "Remove" button  to users without "m.room.redaction" ([#3981](https://github.com/matrix-org/matrix-js-sdk/pull/3981)). Contributed by @rashmitpankhania.
+* ElementR: Ensure Encryption order per room ([#3973](https://github.com/matrix-org/matrix-js-sdk/pull/3973)). Contributed by @BillCarsonFr.
+* Element-R: fix `bootstrapSecretStorage` not resetting key backup when requested ([#3976](https://github.com/matrix-org/matrix-js-sdk/pull/3976)). Contributed by @uhoreg.
+
+
+Changes in [30.3.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v30.3.0) (2023-12-19)
+==================================================================================================
+## ✨ Features
+
+* Element-R: disable sending room key requests ([#3939](https://github.com/matrix-org/matrix-js-sdk/pull/3939)). Contributed by @richvdh.
+
+## 🐛 Bug Fixes
+
+* Fix notifications appearing for old events ([#3946](https://github.com/matrix-org/matrix-js-sdk/pull/3946)). Contributed by @dbkr.
+* Don't back up keys that we got from backup ([#3934](https://github.com/matrix-org/matrix-js-sdk/pull/3934)). Contributed by @uhoreg.
+* Fix upload with empty Content-Type ([#3918](https://github.com/matrix-org/matrix-js-sdk/pull/3918)). Contributed by @JakubOnderka.
+* Prevent phantom notifications from events not in a room's timeline ([#3942](https://github.com/matrix-org/matrix-js-sdk/pull/3942)). Contributed by @dbkr.
+
+
 Changes in [30.2.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v30.2.0) (2023-12-05)
 ==================================================================================================
 ## ✨ Features
@@ -36,6 +141,7 @@ Changes in [30.0.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v30

 ## 🚨 BREAKING CHANGES
 * Refactor & make base64 functions browser-safe ([\#3818](https://github.com/matrix-org/matrix-js-sdk/pull/3818)).
+ * `IndexedDBStore.startup()` must be called after using it on `sdk.createClient` now.

 ## 🦖 Deprecations
 * Deprecate `MatrixEvent.toJSON` ([\#3801](https://github.com/matrix-org/matrix-js-sdk/pull/3801)).
@@ -58,7 +58,7 @@ await client.startClient({ initialSyncLimit: 10 });
 You can perform a call to `/sync` to get the current state of the client:

 ```javascript
-client.once("sync", function (state, prevState, res) {
+client.once(ClientEvent.sync, function (state, prevState, res) {
    if (state === "PREPARED") {
        console.log("prepared");
    } else {
@@ -83,7 +83,7 @@ client.sendEvent("roomId", "m.room.message", content, "", (err, res) => {
 To listen for message events:

 ```javascript
-client.on("Room.timeline", function (event, room, toStartOfTimeline) {
+client.on(RoomEvent.Timeline, function (event, room, toStartOfTimeline) {
    if (event.getType() !== "m.room.message") {
        return; // only use messages
    }
@@ -144,12 +144,12 @@ are updated.

 ```javascript
 // Listen for low-level MatrixEvents
-client.on("event", function (event) {
+client.on(ClientEvent.Event, function (event) {
    console.log(event.getType());
 });

 // Listen for typing changes
-client.on("RoomMember.typing", function (event, member) {
+client.on(RoomMemberEvent.Typing, function (event, member) {
    if (member.typing) {
        console.log(member.name + " is typing...");
    } else {
@@ -211,7 +211,7 @@ const matrixClient = sdk.createClient({
 ### Automatically join rooms when invited

 ```javascript
-matrixClient.on("RoomMember.membership", function (event, member) {
+matrixClient.on(RoomMemberEvent.Membership, function (event, member) {
    if (member.membership === "invite" && member.userId === myUserId) {
        matrixClient.joinRoom(member.roomId).then(function () {
            console.log("Auto-joined %s", member.roomId);
@@ -225,7 +225,7 @@ matrixClient.startClient();
 ### Print out messages for all rooms

 ```javascript
-matrixClient.on("Room.timeline", function (event, room, toStartOfTimeline) {
+matrixClient.on(RoomEvent.Timeline, function (event, room, toStartOfTimeline) {
    if (toStartOfTimeline) {
        return; // don't print paginated results
    }
@@ -257,7 +257,7 @@ Output:
 ### Print out membership lists whenever they are changed

 ```javascript
-matrixClient.on("RoomState.members", function (event, state, member) {
+matrixClient.on(RoomStateEvent.Members, function (event, state, member) {
    const room = matrixClient.getRoom(state.roomId);
    if (!room) {
        return;
@@ -4,6 +4,5 @@

 # Deep dive

-   [Release Process](release.md)
 -   [Storage notes](storage-notes.md)
 -   [Unverified devices](warning-on-unverified-devices.md)
@@ -1,24 +0,0 @@
-# Release Process
-
-## Hotfix and off-cycle releases
-
-1. Prepare the `staging` branch by using the backport automation and manually merging
-2. Go to [Releasing](#Releasing)
-
-## Release candidates
-
-1. Prepare the `staging` branch by running the [branch cut automation](https://github.com/vector-im/element-web/actions/workflows/release_prepare.yml)
-2. Go to [Releasing](#Releasing)
-
-## Releasing
-
-1. Open the [Releases page](https://github.com/matrix-org/matrix-js-sdk/releases) and inspect the draft release there
-2. Make any modifications to the release notes and tag/version as required
-3. Run [workflow](https://github.com/matrix-org/matrix-js-sdk/actions/workflows/release.yml) with the type set appropriately
-
-## Artifacts
-
-Releasing the Matrix JS SDK has just two artifacts:
-
-   Package published to [npm](https://github.com/matrix-org/matrix-js-sdk)
-   Docs published to [Github Pages](https://matrix-org.github.io/matrix-js-sdk/)
@@ -1,12 +1,12 @@
 {
    "name": "matrix-js-sdk",
-    "version": "30.3.0-rc.0",
+    "version": "31.5.0",
    "description": "Matrix Client-Server SDK for Javascript",
    "engines": {
        "node": ">=18.0.0"
    },
    "scripts": {
-        "prepublishOnly": "yarn build",
+        "prepack": "yarn build",
        "start": "echo THIS IS FOR LEGACY PURPOSES ONLY. && babel src -w -s -d lib --verbose --extensions \".ts,.js\"",
        "clean": "rimraf lib",
        "build": "yarn build:dev",
@@ -16,7 +16,7 @@
        "gendoc": "typedoc",
        "lint": "yarn lint:types && yarn lint:js && yarn lint:workflows",
        "lint:js": "eslint --max-warnings 0 src spec && prettier --check .",
-        "lint:js-fix": "prettier --loglevel=warn --write . && eslint --fix src spec",
+        "lint:js-fix": "prettier --log-level=warn --write . && eslint --fix src spec",
        "lint:types": "tsc --noEmit",
        "lint:workflows": "find .github/workflows -type f \\( -iname '*.yaml' -o -iname '*.yml' \\) | xargs -I {} sh -c 'echo \"Linting {}\"; action-validator \"{}\"'",
        "test": "jest",
@@ -52,15 +52,15 @@
    ],
    "dependencies": {
        "@babel/runtime": "^7.12.5",
-        "@matrix-org/matrix-sdk-crypto-wasm": "^3.4.0",
+        "@matrix-org/matrix-sdk-crypto-wasm": "^4.6.0",
        "another-json": "^0.2.0",
        "bs58": "^5.0.0",
        "content-type": "^1.0.4",
-        "jwt-decode": "^3.1.2",
+        "jwt-decode": "^4.0.0",
        "loglevel": "^1.7.1",
        "matrix-events-sdk": "0.0.1",
        "matrix-widget-api": "^1.6.0",
-        "oidc-client-ts": "^2.2.4",
+        "oidc-client-ts": "^3.0.1",
        "p-retry": "4",
        "sdp-transform": "^2.14.1",
        "unhomoglyph": "^1.0.6",
@@ -83,6 +83,7 @@
        "@babel/register": "^7.12.10",
        "@casualbot/jest-sonar-reporter": "2.2.7",
        "@matrix-org/olm": "3.2.15",
+        "@peculiar/webcrypto": "^1.4.5",
        "@types/bs58": "^4.0.1",
        "@types/content-type": "^1.1.5",
        "@types/debug": "^4.1.7",
@@ -91,37 +92,37 @@
        "@types/node": "18",
        "@types/sdp-transform": "^2.4.5",
        "@types/uuid": "9",
-        "@typescript-eslint/eslint-plugin": "^5.45.0",
-        "@typescript-eslint/parser": "^5.45.0",
-        "allchange": "^1.0.6",
+        "@typescript-eslint/eslint-plugin": "^7.0.0",
+        "@typescript-eslint/parser": "^7.0.0",
        "babel-jest": "^29.0.0",
        "debug": "^4.3.4",
        "domexception": "^4.0.0",
-        "eslint": "8.54.0",
+        "eslint": "8.56.0",
        "eslint-config-google": "^0.14.0",
        "eslint-config-prettier": "^9.0.0",
        "eslint-import-resolver-typescript": "^3.5.1",
        "eslint-plugin-import": "^2.26.0",
        "eslint-plugin-jest": "^27.1.6",
-        "eslint-plugin-jsdoc": "^46.0.0",
+        "eslint-plugin-jsdoc": "^48.0.0",
        "eslint-plugin-matrix-org": "^1.0.0",
        "eslint-plugin-tsdoc": "^0.2.17",
-        "eslint-plugin-unicorn": "^49.0.0",
-        "fake-indexeddb": "^5.0.0",
+        "eslint-plugin-unicorn": "^51.0.0",
+        "fake-indexeddb": "^5.0.2",
        "fetch-mock": "9.11.0",
        "fetch-mock-jest": "^1.5.1",
-        "husky": "^8.0.3",
+        "husky": "^9.0.0",
        "jest": "^29.0.0",
        "jest-environment-jsdom": "^29.0.0",
        "jest-localstorage-mock": "^2.4.6",
        "jest-mock": "^29.0.0",
        "lint-staged": "^15.0.2",
        "matrix-mock-request": "^2.5.0",
-        "prettier": "2.8.8",
+        "node-fetch": "^2.7.0",
+        "prettier": "3.2.5",
        "rimraf": "^5.0.0",
        "ts-node": "^10.9.1",
        "typedoc": "^0.24.0",
-        "typedoc-plugin-coverage": "^2.1.0",
+        "typedoc-plugin-coverage": "^3.0.0",
        "typedoc-plugin-mdn-links": "^3.0.3",
        "typedoc-plugin-missing-exports": "^2.0.0",
        "typedoc-plugin-versions": "^0.2.3",
@@ -1,15 +0,0 @@
-#!/bin/bash
-#
-# Script to perform a post-release steps of matrix-js-sdk.
-#
-# Requires:
-#   jq; install from your distribution's package manager (https://stedolan.github.io/jq/)
-
-set -e
-
-jq --version > /dev/null || (echo "jq is required: please install it"; kill $$)
-
-if [ "$(git branch -lr | grep origin/develop -c)" -ge 1 ]; then
-    "$(dirname "$0")/scripts/release/post-merge-master.sh"
-    git push origin develop
-fi
@@ -1,346 +0,0 @@
-#!/bin/bash
-#
-# Script to perform a release of matrix-js-sdk and downstream projects.
-#
-# Requires:
-#   jq; install from your distribution's package manager (https://stedolan.github.io/jq/)
-#   hub; install via brew (macOS) or source/pre-compiled binaries (debian) (https://github.com/github/hub) - Tested on v2.2.9
-#   yarn; install via brew (macOS) or similar (https://yarnpkg.com/docs/install/)
-#
-# Note: this script is also used to release matrix-react-sdk, element-web, and element-desktop.
-
-set -e
-
-jq --version > /dev/null || (echo "jq is required: please install it"; kill $$)
-if [[ $(command -v hub) ]] && [[ $(hub --version) =~ hub[[:space:]]version[[:space:]]([0-9]*).([0-9]*) ]]; then
-    HUB_VERSION_MAJOR=${BASH_REMATCH[1]}
-    HUB_VERSION_MINOR=${BASH_REMATCH[2]}
-    if [[ $HUB_VERSION_MAJOR -lt 2 ]] || [[ $HUB_VERSION_MAJOR -eq 2 && $HUB_VERSION_MINOR -lt 5 ]]; then
-        echo "hub version 2.5 is required, you have $HUB_VERSION_MAJOR.$HUB_VERSION_MINOR installed"
-        exit
-    fi
-else
-    echo "hub is required: please install it"
-    exit
-fi
-yarn --version > /dev/null || (echo "yarn is required: please install it"; kill $$)
-
-USAGE="$0 [-x] [-c changelog_file] vX.Y.Z"
-
-help() {
-    cat <<EOF
-$USAGE
-
-    -c changelog_file:  specify name of file containing changelog
-    -x:                 skip updating the changelog
-EOF
-}
-
-if ! git diff-index --quiet --cached HEAD; then
-    echo "this git checkout has staged (uncommitted) changes. Refusing to release."
-    exit
-fi
-
-if ! git diff-files --quiet; then
-    echo "this git checkout has uncommitted changes. Refusing to release."
-    exit
-fi
-
-skip_changelog=
-changelog_file="CHANGELOG.md"
-while getopts hc:x f; do
-    case $f in
-        h)
-            help
-            exit 0
-            ;;
-        c)
-            changelog_file="$OPTARG"
-            ;;
-        x)
-            skip_changelog=1
-            ;;
-    esac
-done
-shift $(expr $OPTIND - 1)
-
-if [ $# -ne 1 ]; then
-    echo "Usage: $USAGE" >&2
-    exit 1
-fi
-
-function check_dependency {
-    local depver=$(cat package.json | jq -r .dependencies[\"$1\"])
-    if [ "$depver" == "null" ]; then return 0; fi
-
-    echo "Checking version of $1..."
-    local latestver=$(yarn info -s "$1" dist-tags.next)
-    if [ "$depver" != "$latestver" ]
-    then
-        echo "The latest version of $1 is $latestver but package.json depends on $depver."
-        echo -n "Type 'u' to auto-upgrade, 'c' to continue anyway, or 'a' to abort:"
-        read resp
-        if [ "$resp" != "u" ] && [ "$resp" != "c" ]
-        then
-            echo "Aborting."
-            exit 1
-        fi
-        if [ "$resp" == "u" ]
-        then
-            echo "Upgrading $1 to $latestver..."
-            yarn add -E "$1@$latestver"
-            git add -u
-            git commit -m "Upgrade $1 to $latestver"
-        fi
-    fi
-}
-
-function reset_dependency {
-    local depver=$(cat package.json | jq -r .dependencies[\"$1\"])
-    if [ "$depver" == "null" ]; then return 0; fi
-
-    echo "Resetting $1 to develop branch..."
-    yarn add "github:matrix-org/$1#develop"
-    git add -u
-    git commit -m "Reset $1 back to develop branch"
-}
-
-has_subprojects=0
-if [ -f release_config.yaml ]; then
-    subprojects=$(cat release_config.yaml | python -c "import yaml; import sys; print(' '.join(list(yaml.load(sys.stdin)['subprojects'].keys())))" 2> /dev/null)
-    if [ "$?" -eq 0 ]; then
-        has_subprojects=1
-        echo "Checking subprojects for upgrades"
-        for proj in $subprojects; do
-            check_dependency "$proj"
-        done
-    fi
-fi
-
-ret=0
-cat package.json | jq '.dependencies[]' | grep -q '#develop' || ret=$?
-if [ "$ret" -eq 0 ]; then
-    echo "package.json contains develop dependencies. Refusing to release."
-    exit
-fi
-
-# We use Git branch / commit dependencies for some packages, and Yarn seems
-# to have a hard time getting that right. See also
-# https://github.com/yarnpkg/yarn/issues/4734. As a workaround, we clean the
-# global cache here to ensure we get the right thing.
-yarn cache clean
-# Ensure all dependencies are updated
-yarn install --ignore-scripts --frozen-lockfile
-
-# ignore leading v on release
-release="${1#v}"
-tag="v${release}"
-
-prerelease=0
-# We check if this build is a prerelease by looking to
-# see if the version has a hyphen in it. Crude,
-# but semver doesn't support postreleases so anything
-# with a hyphen is a prerelease.
-echo $release | grep -q '-' && prerelease=1
-
-if [ $prerelease -eq 1 ]; then
-    echo Making a PRE-RELEASE
-else
-    read -p "Making a FINAL RELEASE, press enter to continue " REPLY
-fi
-
-rel_branch=$(git symbolic-ref --short HEAD)
-
-if [ -z "$skip_changelog" ]; then
-    echo "Generating changelog"
-    yarn run allchange "$release"
-    read -p "Edit $changelog_file manually, or press enter to continue " REPLY
-
-    if [ -n "$(git ls-files --modified $changelog_file)" ]; then
-        echo "Committing updated changelog"
-        git commit "$changelog_file" -m "Prepare changelog for $tag"
-    fi
-fi
-latest_changes=$(mktemp)
-cat "${changelog_file}" | "$(dirname "$0")/scripts/changelog_head.py" > "${latest_changes}"
-
-set -x
-
-# Bump package.json and build the dist
-echo "yarn version"
-# yarn version will automatically commit its modification
-# and make a release tag. We don't want it to create the tag
-# because it can only sign with the default key, but we can
-# only turn off both of these behaviours, so we have to
-# manually commit the result.
-yarn version --no-git-tag-version --new-version "$release"
-
-"$(dirname "$0")/scripts/release/pre-release.sh"
-
-# commit yarn.lock if it exists, is versioned, and is modified
-if [[ -f yarn.lock && $(git status --porcelain yarn.lock | grep '^ M') ]];
-then
-    pkglock='yarn.lock'
-else
-    pkglock=''
-fi
-git commit package.json $pkglock -m "$tag"
-
-
-# figure out if we should be signing this release
-signing_id=
-if [ -f release_config.yaml ]; then
-    result=$(cat release_config.yaml | python -c "import yaml; import sys; print(yaml.load(sys.stdin)['signing_id'])" 2> /dev/null || true)
-    if [ "$?" -eq 0 ]; then
-        signing_id=$result
-    fi
-fi
-
-
-# If there is a 'dist' script in the package.json,
-# run it in a separate checkout of the project, then
-# upload any files in the 'dist' directory as release
-# assets.
-# We make a completely separate checkout to be sure
-# we're using released versions of the dependencies
-# (rather than whatever we're pulling in from yarn link)
-assets=''
-dodist=0
-jq -e .scripts.dist package.json 2> /dev/null || dodist=$?
-if [ $dodist -eq 0 ]; then
-    projdir=$(pwd)
-    builddir=$(mktemp -d 2>/dev/null || mktemp -d -t 'mytmpdir')
-    echo "Building distribution copy in $builddir"
-    pushd "$builddir"
-    git clone "$projdir" .
-    git checkout "$rel_branch"
-    yarn install --frozen-lockfile
-    # We haven't tagged yet, so tell the dist script what version
-    # it's building
-    DIST_VERSION="$tag" yarn dist
-
-    popd
-
-    for i in "$builddir"/dist/*; do
-        assets="$assets -a $i"
-        if [ -n "$signing_id" ]
-        then
-            gpg -u "$signing_id" --armor --output "$i".asc --detach-sig "$i"
-            assets="$assets -a $i.asc"
-        fi
-    done
-fi
-
-if [ -n "$signing_id" ]; then
-    # make a signed tag
-    # gnupg seems to fail to get the right tty device unless we set it here
-    GIT_COMMITTER_EMAIL="$signing_id" GPG_TTY=$(tty) git tag -u "$signing_id" -F "${latest_changes}" "$tag"
-else
-    git tag -a -F "${latest_changes}" "$tag"
-fi
-
-# push the tag and the release branch
-git push origin "$rel_branch" "$tag"
-
-if [ -n "$signing_id" ]; then
-    # make a signature for the source tarball.
-    #
-    # github will make us a tarball from the tag - we want to create a
-    # signature for it, which means that first of all we need to check that
-    # it's correct.
-    #
-    # we can't deterministically build exactly the same tarball, due to
-    # differences in gzip implementation - but we *can* build the same tar - so
-    # the easiest way to check the validity of the tarball from git is to unzip
-    # it and compare it with our own idea of what the tar should look like.
-
-    # This uses git archive which seems to be what github uses. Specifically,
-    # the header fields are set in the same way: same file mode, uid & gid
-    # both zero and mtime set to the timestamp of the commit that the tag
-    # references. Also note that this puts the commit into the tar headers
-    # and can be extracted with gunzip -c foo.tar.gz | git get-tar-commit-id
-
-    # the name of the sig file we want to create
-    source_sigfile="${tag}-src.tar.gz.asc"
-
-    tarfile="$tag.tar.gz"
-    gh_project_url=$(git remote get-url origin |
-                            sed -e 's#^git@github\.com:#https://github.com/#' \
-                                -e 's#^git\+ssh://git@github\.com/#https://github.com/#' \
-                                -e 's/\.git$//')
-    project_name="${gh_project_url##*/}"
-    curl -L "${gh_project_url}/archive/${tarfile}" -o "${tarfile}"
-
-    # unzip it and compare it with the tar we would generate
-    if ! cmp --silent <(gunzip -c $tarfile) \
-         <(git archive --format tar --prefix="${project_name}-${release}/" "$tag"); then
-
-        # we don't bail out here, because really it's more likely that our comparison
-        # screwed up and it's super annoying to abort the script at this point.
-        cat >&2 <<EOF
-!!!!!!!!!!!!!!!!!
-!!!! WARNING !!!!
-
-Mismatch between our own tarfile and that generated by github: not signing
-source tarball.
-
-To resolve, determine if $tarfile is correct, and if so sign it with gpg and
-attach it to the release as $source_sigfile.
-
-!!!!!!!!!!!!!!!!!
-EOF
-    else
-        gpg -u "$signing_id" --armor --output "$source_sigfile" --detach-sig "$tarfile"
-        assets="$assets -a $source_sigfile"
-    fi
-fi
-
-hubflags=''
-if [ $prerelease -eq 1 ]; then
-    hubflags='-p'
-fi
-
-release_text=$(mktemp)
-echo "$tag" > "${release_text}"
-echo >> "${release_text}"
-cat "${latest_changes}" >> "${release_text}"
-hub release create $hubflags $assets -F "${release_text}" "$tag"
-
-if [ $dodist -eq 0 ]; then
-    rm -rf "$builddir"
-fi
-rm "${release_text}"
-rm "${latest_changes}"
-
-# if it is a pre-release, leave it on the release branch for now.
-if [ $prerelease -eq 1 ]; then
-    git checkout "$rel_branch"
-    exit 0
-fi
-
-# merge release branch to master
-echo "updating master branch"
-git checkout master
-git pull
-git merge "$rel_branch" --no-edit
-
-# push master to github
-git push origin master
-
-# finally, merge master back onto develop (if it exists)
-if [ "$(git branch -lr | grep origin/develop -c)" -ge 1 ]; then
-    git checkout develop
-    git pull
-    git merge master --no-edit
-    git push origin develop
-fi
-
-[ -x ./post-release.sh ] && ./post-release.sh
-
-if [ $has_subprojects -eq 1 ] && [ $prerelease -eq 0 ]; then
-    echo "Resetting subprojects to develop"
-    for proj in $subprojects; do
-        reset_dependency "$proj"
-    done
-    git push origin develop
-fi
@@ -2,16 +2,70 @@

 const fs = require("fs");

+async function listReleases(github, owner, repo) {
+    const response = await github.rest.repos.listReleases({
+        owner,
+        repo,
+        per_page: 100,
+    });
+    // Filters out draft releases
+    return response.data.filter((release) => !release.draft);
+}
+
+// Dependency can be a tuple of dependency, from version, to version, in which case a list of releases in that range (to inclusive) will be returned
+// Or it can be a string in the form accepted by `getRelease`
+async function getReleases(github, dependency) {
+    if (Array.isArray(dependency)) {
+        const [dep, fromVersion, toVersion] = dependency;
+        const upstreamPackageJson = getDependencyPackageJson(dep);
+        const [owner, repo] = upstreamPackageJson.repository.url.split("/").slice(-2);
+
+        const unfilteredReleases = await listReleases(github, owner, repo);
+        // Only include non-draft & non-prerelease releases, unless the to-release is a pre-release, include that one
+        const releases = unfilteredReleases.filter(
+            (release) => !release.prerelease || release.tag_name === `v${toVersion}`,
+        );
+
+        const fromVersionIndex = releases.findIndex((release) => release.tag_name === `v${fromVersion}`);
+        const toVersionIndex = releases.findIndex((release) => release.tag_name === `v${toVersion}`);
+
+        return releases.slice(toVersionIndex, fromVersionIndex);
+    }
+
+    return [await getRelease(github, dependency)];
+}
+
+// Dependency can be the name of an entry in package.json, in which case the owner, repo & version will be looked up in its own package.json
+// Or it can be a string in the form owner/repo@tag - in this case the tag is used exactly to find the release
+// Or it can be a string in the form owner/repo~tag - in this case the latest tag in the same major.minor.patch set is used to find the release
 async function getRelease(github, dependency) {
    let owner;
    let repo;
    let tag;
-    if (dependency.includes("/") && dependency.includes("@")) {
-        owner = dependency.split("/")[0];
-        repo = dependency.split("/")[1].split("@")[0];
-        tag = dependency.split("@")[1];
+
+    if (dependency.includes("/")) {
+        let rest;
+        [owner, rest] = dependency.split("/")[0];
+
+        if (dependency.includes("@")) {
+            [repo, tag] = rest.split("@");
+        } else if (dependency.includes("~")) {
+            [repo, tag] = rest.split("~");
+
+            if (tag.includes("-rc.")) {
+                // If the tag is an RC, find the latest matching RC in the set
+                try {
+                    const releases = await listReleases(github, owner, repo);
+                    const baseVersion = tag.split("-rc.")[0];
+                    const release = releases.find((release) => release.tag_name.startsWith(baseVersion));
+                    if (release) return release;
+                } catch (e) {
+                    // Fall back to getReleaseByTag
+                }
+            }
+        }
    } else {
-        const upstreamPackageJson = JSON.parse(fs.readFileSync(`./node_modules/${dependency}/package.json`, "utf8"));
+        const upstreamPackageJson = getDependencyPackageJson(dependency);
        [owner, repo] = upstreamPackageJson.repository.url.split("/").slice(-2);
        tag = `v${upstreamPackageJson.version}`;
    }
@@ -24,25 +78,45 @@ async function getRelease(github, dependency) {
    return response.data;
 }

+function getDependencyPackageJson(dependency) {
+    return JSON.parse(fs.readFileSync(`./node_modules/${dependency}/package.json`, "utf8"));
+}
+
 const HEADING_PREFIX = "## ";

+const categories = [
+    "🔒 SECURITY FIXES",
+    "🚨 BREAKING CHANGESd",
+    "🦖 Deprecations",
+    "✨ Features",
+    "🐛 Bug Fixes",
+    "🧰 Maintenance",
+];
+
+const parseReleaseNotes = (body, sections) => {
+    let heading = null;
+    for (const line of body.split("\n")) {
+        const trimmed = line.trim();
+        if (trimmed.startsWith(HEADING_PREFIX)) {
+            heading = trimmed.slice(HEADING_PREFIX.length);
+            if (!categories.includes(heading)) heading = null;
+            continue;
+        }
+        if (heading && trimmed) {
+            sections[heading].push(trimmed);
+        }
+    }
+};
+
 const main = async ({ github, releaseId, dependencies }) => {
    const { GITHUB_REPOSITORY } = process.env;
    const [owner, repo] = GITHUB_REPOSITORY.split("/");

-    const sections = new Map();
-    let heading = null;
+    const sections = Object.fromEntries(categories.map((cat) => [cat, []]));
    for (const dependency of dependencies) {
-        const release = await getRelease(github, dependency);
-        for (const line of release.body.split("\n")) {
-            if (line.startsWith(HEADING_PREFIX)) {
-                heading = line.trim();
-                sections.set(heading, []);
-                continue;
-            }
-            if (heading && line) {
-                sections.get(heading).push(line.trim());
-            }
+        const releases = await getReleases(github, dependency);
+        for (const release of releases) {
+            parseReleaseNotes(release.body, sections);
        }
    }

@@ -52,36 +126,22 @@ const main = async ({ github, releaseId, dependencies }) => {
        release_id: releaseId,
    });

-    const headings = ["🚨 BREAKING CHANGES", "🦖 Deprecations", "✨ Features", "🐛 Bug Fixes", "🧰 Maintenance"].map(
-        (h) => HEADING_PREFIX + h,
-    );
+    const intro = release.body.split(HEADING_PREFIX, 2)[0].trim();

-    heading = null;
-    const output = [];
-    for (const line of [...release.body.split("\n"), null]) {
-        if (line === null || line.startsWith(HEADING_PREFIX)) {
-            // If we have a heading, and it's not the first in the list of pending headings, output the section.
-            // If we're processing the last line (null) then output all remaining sections.
-            while (headings.length > 0 && (line === null || (heading && headings[0] !== heading))) {
-                const heading = headings.shift();
-                if (sections.has(heading)) {
-                    output.push(heading);
-                    output.push(...sections.get(heading));
-                }
-            }
-
-            if (heading && sections.has(heading)) {
-                const lastIsBlank = !output.at(-1)?.trim();
-                if (lastIsBlank) output.pop();
-                output.push(...sections.get(heading));
-                if (lastIsBlank) output.push("");
-            }
-            heading = line;
-        }
-        output.push(line);
+    let output = "";
+    if (intro) {
+        output = intro + "\n\n";
    }

-    return output.join("\n");
+    for (const section in sections) {
+        const lines = sections[section];
+        if (!lines.length) continue;
+        output += HEADING_PREFIX + section + "\n\n";
+        output += lines.join("\n");
+        output += "\n\n";
+    }
+
+    return output;
 };

 // This is just for testing locally
@@ -398,7 +398,8 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("cross-signing (%s)", (backend: s

    describe("crossSignDevice", () => {
        beforeEach(async () => {
-            jest.useFakeTimers();
+            // We want to use fake timers, but the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
+            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });

            // make sure that there is another device which we can sign
            e2eKeyResponder.addDeviceKeys(SIGNED_TEST_DEVICE_DATA);
@@ -29,6 +29,7 @@ import {
    getSyncResponse,
    InitCrypto,
    mkEventCustom,
+    mkMembershipCustom,
    syncPromise,
 } from "../../test-utils/test-utils";
 import * as testData from "../../test-utils/test-data";
@@ -38,6 +39,7 @@ import {
    BOB_TEST_USER_ID,
    SIGNED_CROSS_SIGNING_KEYS_DATA,
    SIGNED_TEST_DEVICE_DATA,
+    TEST_ROOM_ID,
    TEST_ROOM_ID as ROOM_ID,
    TEST_USER_ID,
 } from "../../test-utils/test-data";
@@ -74,7 +76,7 @@ import {
    mockSetupCrossSigningRequests,
    mockSetupMegolmBackupRequests,
 } from "../../test-utils/mockEndpoints";
-import { AddSecretStorageKeyOpts } from "../../../src/secret-storage";
+import { SecretStorageKeyDescription } from "../../../src/secret-storage";
 import {
    CrossSigningKey,
    CryptoCallbacks,
@@ -230,9 +232,6 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
    /** an object which intercepts `/keys/upload` requests from {@link #aliceClient} to catch the uploaded keys */
    let keyReceiver: E2EKeyReceiver;

-    /** an object which intercepts `/keys/query` requests on the test homeserver */
-    let keyResponder: E2EKeyResponder;
-
    /** an object which intercepts `/sync` requests from {@link #aliceClient} */
    let syncResponder: ISyncResponder;

@@ -340,7 +339,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
    function createCryptoCallbacks(): CryptoCallbacks {
        // Store the cached secret storage key and return it when `getSecretStorageKey` is called
        let cachedKey: { keyId: string; key: Uint8Array };
-        const cacheSecretStorageKey = (keyId: string, keyInfo: AddSecretStorageKeyOpts, key: Uint8Array) => {
+        const cacheSecretStorageKey = (keyId: string, keyInfo: SecretStorageKeyDescription, key: Uint8Array) => {
            cachedKey = {
                keyId,
                key,
@@ -368,6 +367,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
                accessToken: "akjgkrgjs",
                deviceId: "xzcvb",
                cryptoCallbacks: createCryptoCallbacks(),
+                logger: logger.getChild("aliceClient"),
            });

            /* set up listeners for /keys/upload and /sync */
@@ -398,17 +398,11 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
        expect(aliceClient.getCrypto()).toHaveProperty("globalBlacklistUnverifiedDevices");
    });

-    it("CryptoAPI.getOwnedDeviceKeys returns the correct values", async () => {
-        const homeserverUrl = aliceClient.getHomeserverUrl();
-
-        keyResponder = new E2EKeyResponder(homeserverUrl);
-        await startClientAndAwaitFirstSync();
-        keyResponder.addKeyReceiver("@alice:localhost", keyReceiver);
-
+    it("CryptoAPI.getOwnDeviceKeys returns plausible values", async () => {
        const deviceKeys = await aliceClient.getCrypto()!.getOwnDeviceKeys();
-
-        expect(deviceKeys.curve25519).toEqual(keyReceiver.getDeviceKey());
-        expect(deviceKeys.ed25519).toEqual(keyReceiver.getSigningKey());
+        // We just check for a 43-character base64 string
+        expect(deviceKeys.curve25519).toMatch(/^[A-Za-z0-9+/]{43}$/);
+        expect(deviceKeys.ed25519).toMatch(/^[A-Za-z0-9+/]{43}$/);
    });

    it("Alice receives a megolm message", async () => {
@@ -707,7 +701,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,

    it("prepareToEncrypt", async () => {
        const homeserverUrl = aliceClient.getHomeserverUrl();
-        keyResponder = new E2EKeyResponder(homeserverUrl);
+        const keyResponder = new E2EKeyResponder(homeserverUrl);
        keyResponder.addKeyReceiver("@alice:localhost", keyReceiver);

        const testDeviceKeys = getTestOlmAccountKeys(testOlmAccount, "@bob:xyz", "DEVICE_ID");
@@ -738,7 +732,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
    it("Alice sends a megolm message with GlobalErrorOnUnknownDevices=false", async () => {
        aliceClient.setGlobalErrorOnUnknownDevices(false);
        const homeserverUrl = aliceClient.getHomeserverUrl();
-        keyResponder = new E2EKeyResponder(homeserverUrl);
+        const keyResponder = new E2EKeyResponder(homeserverUrl);
        keyResponder.addKeyReceiver("@alice:localhost", keyReceiver);

        const testDeviceKeys = getTestOlmAccountKeys(testOlmAccount, "@bob:xyz", "DEVICE_ID");
@@ -766,7 +760,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
    it("We should start a new megolm session after forceDiscardSession", async () => {
        aliceClient.setGlobalErrorOnUnknownDevices(false);
        const homeserverUrl = aliceClient.getHomeserverUrl();
-        keyResponder = new E2EKeyResponder(homeserverUrl);
+        const keyResponder = new E2EKeyResponder(homeserverUrl);
        keyResponder.addKeyReceiver("@alice:localhost", keyReceiver);

        const testDeviceKeys = getTestOlmAccountKeys(testOlmAccount, "@bob:xyz", "DEVICE_ID");
@@ -1069,8 +1063,9 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
            await startClientAndAwaitFirstSync();
            const p2pSession = await establishOlmSession(aliceClient, keyReceiver, syncResponder, testOlmAccount);

-            // We need to fake the timers to advance the time
-            jest.useFakeTimers();
+            // We need to fake the timers to advance the time, but the wasm bindings of matrix-sdk-crypto rely on a
+            // working `queueMicrotask`
+            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });

            const syncResponse = getSyncResponse(["@bob:xyz"]);

@@ -1384,7 +1379,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
        });
        expect(decryptedEvent.getContent().body).toEqual("42");

-        const exported = await aliceClient.exportRoomKeys();
+        const exported = await aliceClient.getCrypto()!.exportRoomKeysAsJson();

        // start a new client
        await aliceClient.stopClient();
@@ -1400,7 +1395,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
        keyReceiver = new E2EKeyReceiver(homeserverUrl);
        syncResponder = new SyncResponder(homeserverUrl);
        await initCrypto(aliceClient);
-        await aliceClient.importRoomKeys(exported);
+        await aliceClient.getCrypto()!.importRoomKeysAsJson(exported);
        expectAliceKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
        await startClientAndAwaitFirstSync();

@@ -2075,7 +2070,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,

        it("Sending an event initiates a member list sync", async () => {
            const homeserverUrl = aliceClient.getHomeserverUrl();
-            keyResponder = new E2EKeyResponder(homeserverUrl);
+            const keyResponder = new E2EKeyResponder(homeserverUrl);
            keyResponder.addKeyReceiver("@alice:localhost", keyReceiver);

            const testDeviceKeys = getTestOlmAccountKeys(testOlmAccount, "@bob:xyz", "DEVICE_ID");
@@ -2098,7 +2093,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,

        it("loading the membership list inhibits a later load", async () => {
            const homeserverUrl = aliceClient.getHomeserverUrl();
-            keyResponder = new E2EKeyResponder(homeserverUrl);
+            const keyResponder = new E2EKeyResponder(homeserverUrl);
            keyResponder.addKeyReceiver("@alice:localhost", keyReceiver);

            const testDeviceKeys = getTestOlmAccountKeys(testOlmAccount, "@bob:xyz", "DEVICE_ID");
@@ -2195,7 +2190,8 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,

    describe("key upload request", () => {
        beforeEach(() => {
-            jest.useFakeTimers();
+            // We want to use fake timers, but the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
+            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
        });

        afterEach(() => {
@@ -2395,8 +2391,9 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
            expect(devicesInfo.get(user)?.size).toBeFalsy();
        });

-        it("Get devices from tacked users", async () => {
-            jest.useFakeTimers();
+        it("Get devices from tracked users", async () => {
+            // We want to use fake timers, but the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
+            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });

            expectAliceKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
            await startClientAndAwaitFirstSync();
@@ -2567,6 +2564,30 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
            await backupStatusUpdate;
        }

+        describe("Generate 4S recovery keys", () => {
+            it("should create a random recovery key", async () => {
+                const generatedKey = await aliceClient.getCrypto()!.createRecoveryKeyFromPassphrase();
+                expect(generatedKey.privateKey).toBeDefined();
+                expect(generatedKey.privateKey).toBeInstanceOf(Uint8Array);
+                expect(generatedKey.privateKey.length).toBe(32);
+                expect(generatedKey.keyInfo?.passphrase).toBeUndefined();
+                expect(generatedKey.encodedPrivateKey).toBeDefined();
+                expect(generatedKey.encodedPrivateKey!.indexOf("Es")).toBe(0);
+            });
+
+            it("should create a recovery key from passphrase", async () => {
+                const generatedKey = await aliceClient.getCrypto()!.createRecoveryKeyFromPassphrase("mypassphrase");
+                expect(generatedKey.privateKey).toBeDefined();
+                expect(generatedKey.privateKey).toBeInstanceOf(Uint8Array);
+                expect(generatedKey.privateKey.length).toBe(32);
+                expect(generatedKey.keyInfo?.passphrase?.algorithm).toBe("m.pbkdf2");
+                expect(generatedKey.keyInfo?.passphrase?.iterations).toBe(500000);
+
+                expect(generatedKey.encodedPrivateKey).toBeDefined();
+                expect(generatedKey.encodedPrivateKey!.indexOf("Es")).toBe(0);
+            });
+        });
+
        describe("bootstrapSecretStorage", () => {
            // Doesn't work with legacy crypto, which will try to bootstrap even without private key, which is buggy.
            newBackendOnly(
@@ -2592,6 +2613,14 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
                // Wait for the key to be uploaded in the account data
                const secretStorageKey = await awaitSecretStorageKeyStoredInAccountData();

+                // check that the key content contains the key check info
+                const keyContent = accountDataAccumulator.accountDataEvents.get(
+                    `m.secret_storage.key.${secretStorageKey}`,
+                )!;
+                // In order to verify if the key is valid, a zero secret is encrypted with the key
+                expect(keyContent.iv).toBeDefined();
+                expect(keyContent.mac).toBeDefined();
+
                // Return the newly created key in the sync response
                accountDataAccumulator.sendSyncResponseWithUpdatedAccountData(syncResponder);

@@ -2719,7 +2748,8 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,

        describe("Manage Key Backup", () => {
            beforeEach(async () => {
-                jest.useFakeTimers();
+                // We want to use fake timers, but the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
+                jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
            });

            afterEach(() => {
@@ -2873,7 +2903,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
            // anything that we don't have a specific matcher for silently returns a 404
            fetchMock.catch(404);

-            keyResponder = new E2EKeyResponder(aliceClient.getHomeserverUrl());
+            const keyResponder = new E2EKeyResponder(aliceClient.getHomeserverUrl());
            keyResponder.addCrossSigningData(SIGNED_CROSS_SIGNING_KEYS_DATA);
            keyResponder.addDeviceKeys(SIGNED_TEST_DEVICE_DATA);
            keyResponder.addKeyReceiver(BOB_TEST_USER_ID, keyReceiver);
@@ -2909,4 +2939,180 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
            expect(hasCrossSigningKeysForUser).toBe(false);
        });
    });
+
+    /** Guards against downgrade attacks from servers hiding or manipulating the crypto settings. */
+    describe("Persistent encryption settings", () => {
+        let persistentStoreClient: MatrixClient;
+        let client2: MatrixClient;
+
+        beforeEach(async () => {
+            const homeserverurl = "https://alice-server.com";
+            const userId = "@alice:localhost";
+
+            const keyResponder = new E2EKeyResponder(homeserverurl);
+            keyResponder.addKeyReceiver(userId, keyReceiver);
+
+            // For legacy crypto, these tests only work properly with a proper (indexeddb-based) CryptoStore, so
+            // rather than using the existing `aliceClient`, create a new client. Once we drop legacy crypto, we can
+            // just use `aliceClient` here.
+            persistentStoreClient = await makeNewClient(homeserverurl, userId, "persistentStoreClient");
+            await persistentStoreClient.startClient({});
+        });
+
+        afterEach(async () => {
+            persistentStoreClient.stopClient();
+            client2?.stopClient();
+        });
+
+        test("Sending a message in a room where the server is hiding the state event does not send a plaintext event", async () => {
+            // Alice is in an encrypted room
+            const encryptionState = mkEncryptionEvent({ algorithm: "m.megolm.v1.aes-sha2" });
+            syncResponder.sendOrQueueSyncResponse(getSyncResponseWithState([encryptionState]));
+            await syncPromise(persistentStoreClient);
+
+            // Send a message, and expect to get an `m.room.encrypted` event.
+            await Promise.all([persistentStoreClient.sendTextMessage(ROOM_ID, "test"), expectEncryptedSendMessage()]);
+
+            // We now replace the client, and allow the new one to resync, *without* the encryption event.
+            client2 = await replaceClient(persistentStoreClient);
+            syncResponder.sendOrQueueSyncResponse(getSyncResponseWithState([]));
+            await client2.startClient({});
+            await syncPromise(client2);
+            logger.log(client2.getUserId() + ": restarted");
+
+            await expectSendMessageToFail(client2);
+        });
+
+        test("Changes to the rotation period should be ignored", async () => {
+            // Alice is in an encrypted room, where the rotation period is set to 2 messages
+            const encryptionState = mkEncryptionEvent({ algorithm: "m.megolm.v1.aes-sha2", rotation_period_msgs: 2 });
+            syncResponder.sendOrQueueSyncResponse(getSyncResponseWithState([encryptionState]));
+            await syncPromise(persistentStoreClient);
+
+            // Send a message, and expect to get an `m.room.encrypted` event.
+            const [, msg1Content] = await Promise.all([
+                persistentStoreClient.sendTextMessage(ROOM_ID, "test1"),
+                expectEncryptedSendMessage(),
+            ]);
+
+            // Replace the state with one which bumps the rotation period. This should be ignored, though it's not
+            // clear that is correct behaviour (see https://github.com/element-hq/element-meta/issues/69)
+            const encryptionState2 = mkEncryptionEvent({
+                algorithm: "m.megolm.v1.aes-sha2",
+                rotation_period_msgs: 100,
+            });
+            syncResponder.sendOrQueueSyncResponse({
+                next_batch: "1",
+                rooms: { join: { [TEST_ROOM_ID]: { timeline: { events: [encryptionState2], prev_batch: "" } } } },
+            });
+            await syncPromise(persistentStoreClient);
+
+            // Send two more messages. The first should use the same megolm session as the first; the second should
+            // use a different one.
+            const [, msg2Content] = await Promise.all([
+                persistentStoreClient.sendTextMessage(ROOM_ID, "test2"),
+                expectEncryptedSendMessage(),
+            ]);
+            expect(msg2Content.session_id).toEqual(msg1Content.session_id);
+            const [, msg3Content] = await Promise.all([
+                persistentStoreClient.sendTextMessage(ROOM_ID, "test3"),
+                expectEncryptedSendMessage(),
+            ]);
+            expect(msg3Content.session_id).not.toEqual(msg1Content.session_id);
+        });
+
+        test("Changes to the rotation period should be ignored after a client restart", async () => {
+            // Alice is in an encrypted room, where the rotation period is set to 2 messages
+            const encryptionState = mkEncryptionEvent({ algorithm: "m.megolm.v1.aes-sha2", rotation_period_msgs: 2 });
+            syncResponder.sendOrQueueSyncResponse(getSyncResponseWithState([encryptionState]));
+            await syncPromise(persistentStoreClient);
+
+            // Send a message, and expect to get an `m.room.encrypted` event.
+            await Promise.all([persistentStoreClient.sendTextMessage(ROOM_ID, "test1"), expectEncryptedSendMessage()]);
+
+            // We now replace the client, and allow the new one to resync with a *different* encryption event.
+            client2 = await replaceClient(persistentStoreClient);
+            const encryptionState2 = mkEncryptionEvent({
+                algorithm: "m.megolm.v1.aes-sha2",
+                rotation_period_msgs: 100,
+            });
+            syncResponder.sendOrQueueSyncResponse(getSyncResponseWithState([encryptionState2]));
+            await client2.startClient({});
+            await syncPromise(client2);
+            logger.log(client2.getUserId() + ": restarted");
+
+            // Now send another message, which should (for now) be rejected.
+            await expectSendMessageToFail(client2);
+        });
+
+        /** Shut down `oldClient`, and build a new MatrixClient for the same user. */
+        async function replaceClient(oldClient: MatrixClient) {
+            oldClient.stopClient();
+            syncResponder.sendOrQueueSyncResponse({}); // flush pending request from old client
+            return makeNewClient(oldClient.getHomeserverUrl(), oldClient.getSafeUserId(), "client2");
+        }
+
+        async function makeNewClient(
+            homeserverUrl: string,
+            userId: string,
+            loggerPrefix: string,
+        ): Promise<MatrixClient> {
+            const client = createClient({
+                baseUrl: homeserverUrl,
+                userId: userId,
+                accessToken: "akjgkrgjs",
+                deviceId: "xzcvb",
+                cryptoCallbacks: createCryptoCallbacks(),
+                logger: logger.getChild(loggerPrefix),
+
+                // For legacy crypto, these tests only work with a proper persistent cryptoStore.
+                cryptoStore: new IndexedDBCryptoStore(indexedDB, "test"),
+            });
+            await initCrypto(client);
+            mockInitialApiRequests(client.getHomeserverUrl());
+            return client;
+        }
+
+        function mkEncryptionEvent(content: Object) {
+            return mkEventCustom({
+                sender: persistentStoreClient.getSafeUserId(),
+                type: "m.room.encryption",
+                state_key: "",
+                content: content,
+            });
+        }
+
+        /** Sync response which includes `TEST_ROOM_ID`, where alice is a member
+         *
+         * @param stateEvents - Additional state events for the test room
+         */
+        function getSyncResponseWithState(stateEvents: Array<Object>) {
+            const roomResponse = {
+                state: {
+                    events: [
+                        mkMembershipCustom({ membership: "join", sender: persistentStoreClient.getSafeUserId() }),
+                        ...stateEvents,
+                    ],
+                },
+                timeline: {
+                    events: [],
+                    prev_batch: "",
+                },
+            };
+
+            return {
+                next_batch: "1",
+                rooms: { join: { [TEST_ROOM_ID]: roomResponse } },
+            };
+        }
+
+        /** Send a message with the given client, and check that it is not sent in plaintext */
+        async function expectSendMessageToFail(aliceClient2: MatrixClient) {
+            // The precise failure mode here is somewhat up for debate (https://github.com/element-hq/element-meta/issues/69).
+            // For now, the attempt to send is rejected with an exception. The text is different between old and new stacks.
+            await expect(aliceClient2.sendTextMessage(ROOM_ID, "test")).rejects.toThrow(
+                /unconfigured room !room:id|Room !room:id was previously configured to use encryption/,
+            );
+        }
+    });
 });
@@ -17,8 +17,18 @@ limitations under the License.
 import fetchMock from "fetch-mock-jest";
 import "fake-indexeddb/auto";
 import { IDBFactory } from "fake-indexeddb";
+import { Mocked } from "jest-mock";

-import { createClient, CryptoEvent, ICreateClientOpts, IEvent, MatrixClient, TypedEventEmitter } from "../../../src";
+import {
+    createClient,
+    CryptoApi,
+    CryptoEvent,
+    ICreateClientOpts,
+    IEvent,
+    IMegolmSessionData,
+    MatrixClient,
+    TypedEventEmitter,
+} from "../../../src";
 import { SyncResponder } from "../../test-utils/SyncResponder";
 import { E2EKeyReceiver } from "../../test-utils/E2EKeyReceiver";
 import { E2EKeyResponder } from "../../test-utils/E2EKeyResponder";
@@ -31,7 +41,7 @@ import {
    syncPromise,
 } from "../../test-utils/test-utils";
 import * as testData from "../../test-utils/test-data";
-import { KeyBackupInfo } from "../../../src/crypto-api/keybackup";
+import { KeyBackupInfo, KeyBackupSession } from "../../../src/crypto-api/keybackup";
 import { IKeyBackup } from "../../../src/crypto/backup";
 import { flushPromises } from "../../test-utils/flushPromises";
 import { defer, IDeferred } from "../../../src/utils";
@@ -119,7 +129,8 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
    let e2eKeyResponder: E2EKeyResponder;

    beforeEach(async () => {
-        jest.useFakeTimers();
+        // We want to use fake timers, but the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
+        jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });

        // anything that we don't have a specific matcher for silently returns a 404
        fetchMock.catch(404);
@@ -286,17 +297,21 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
    });

    describe("recover from backup", () => {
-        it("can restore from backup (Curve25519 version)", async function () {
+        let aliceCrypto: CryptoApi;
+
+        beforeEach(async () => {
            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);

            aliceClient = await initTestClient();
-            const aliceCrypto = aliceClient.getCrypto()!;
+            aliceCrypto = aliceClient.getCrypto()!;
            await aliceClient.startClient();

            // tell Alice to trust the dummy device that signed the backup
            await waitForDeviceList();
            await aliceCrypto.setDeviceVerified(testData.TEST_USER_ID, testData.TEST_DEVICE_ID);
+        });

+        it("can restore from backup (Curve25519 version)", async function () {
            const fullBackup = {
                rooms: {
                    [ROOM_ID]: {
@@ -340,17 +355,179 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
            expect(afterCache.imported).toStrictEqual(1);
        });

+        /**
+         * Creates a mock backup response of a GET `room_keys/keys` with a given number of keys per room.
+         * @param keysPerRoom The number of keys per room
+         */
+        function createBackupDownloadResponse(keysPerRoom: number[]) {
+            const response: {
+                rooms: {
+                    [roomId: string]: {
+                        sessions: {
+                            [sessionId: string]: KeyBackupSession;
+                        };
+                    };
+                };
+            } = { rooms: {} };
+
+            const expectedTotal = keysPerRoom.reduce((a, b) => a + b, 0);
+            for (let i = 0; i < keysPerRoom.length; i++) {
+                const roomId = `!room${i}:example.com`;
+                response.rooms[roomId] = { sessions: {} };
+                for (let j = 0; j < keysPerRoom[i]; j++) {
+                    const sessionId = `session${j}`;
+                    // Put the same fake session data, not important for that test
+                    response.rooms[roomId].sessions[sessionId] = testData.CURVE25519_KEY_BACKUP_DATA;
+                }
+            }
+            return { response, expectedTotal };
+        }
+
+        it("Should import full backup in chunks", async function () {
+            const importMockImpl = jest.fn();
+            // @ts-ignore - mock a private method for testing purpose
+            aliceCrypto.importBackedUpRoomKeys = importMockImpl;
+
+            // We need several rooms with several sessions to test chunking
+            const { response, expectedTotal } = createBackupDownloadResponse([45, 300, 345, 12, 130]);
+
+            fetchMock.get("express:/_matrix/client/v3/room_keys/keys", response);
+
+            const check = await aliceCrypto.checkKeyBackupAndEnable();
+
+            const progressCallback = jest.fn();
+            const result = await aliceClient.restoreKeyBackupWithRecoveryKey(
+                testData.BACKUP_DECRYPTION_KEY_BASE58,
+                undefined,
+                undefined,
+                check!.backupInfo!,
+                {
+                    progressCallback,
+                },
+            );
+
+            expect(result.imported).toStrictEqual(expectedTotal);
+            // Should be called 5 times: 200*4 plus one chunk with the remaining 32
+            expect(importMockImpl).toHaveBeenCalledTimes(5);
+            for (let i = 0; i < 4; i++) {
+                expect(importMockImpl.mock.calls[i][0].length).toEqual(200);
+            }
+            expect(importMockImpl.mock.calls[4][0].length).toEqual(32);
+
+            expect(progressCallback).toHaveBeenCalledWith({
+                stage: "fetch",
+            });
+
+            // Should be called 4 times and report 200/400/600/800
+            for (let i = 0; i < 4; i++) {
+                expect(progressCallback).toHaveBeenCalledWith({
+                    total: expectedTotal,
+                    successes: (i + 1) * 200,
+                    stage: "load_keys",
+                    failures: 0,
+                });
+            }
+
+            // The last chunk
+            expect(progressCallback).toHaveBeenCalledWith({
+                total: expectedTotal,
+                successes: 832,
+                stage: "load_keys",
+                failures: 0,
+            });
+        });
+
+        it("Should continue to process backup if a chunk import fails and report failures", async function () {
+            // @ts-ignore - mock a private method for testing purpose
+            aliceCrypto.importBackedUpRoomKeys = jest
+                .fn()
+                .mockImplementationOnce(() => {
+                    // Fail to import first chunk
+                    throw new Error("test error");
+                })
+                // Ok for other chunks
+                .mockResolvedValue(undefined);
+
+            const { response, expectedTotal } = createBackupDownloadResponse([100, 300]);
+
+            fetchMock.get("express:/_matrix/client/v3/room_keys/keys", response);
+
+            const check = await aliceCrypto.checkKeyBackupAndEnable();
+
+            const progressCallback = jest.fn();
+            const result = await aliceClient.restoreKeyBackupWithRecoveryKey(
+                testData.BACKUP_DECRYPTION_KEY_BASE58,
+                undefined,
+                undefined,
+                check!.backupInfo!,
+                {
+                    progressCallback,
+                },
+            );
+
+            expect(result.total).toStrictEqual(expectedTotal);
+            // A chunk failed to import
+            expect(result.imported).toStrictEqual(200);
+
+            expect(progressCallback).toHaveBeenCalledWith({
+                total: expectedTotal,
+                successes: 0,
+                stage: "load_keys",
+                failures: 200,
+            });
+
+            expect(progressCallback).toHaveBeenCalledWith({
+                total: expectedTotal,
+                successes: 200,
+                stage: "load_keys",
+                failures: 200,
+            });
+        });
+
+        it("Should continue if some keys fails to decrypt", async function () {
+            // @ts-ignore - mock a private method for testing purpose
+            aliceCrypto.importBackedUpRoomKeys = jest.fn();
+
+            const decryptionFailureCount = 2;
+
+            const mockDecryptor = {
+                // DecryptSessions does not reject on decryption failure, but just skip the key
+                decryptSessions: jest.fn().mockImplementation((sessions) => {
+                    // simulate fail to decrypt 2 keys out of all
+                    const decrypted = [];
+                    const keys = Object.keys(sessions);
+                    for (let i = 0; i < keys.length - decryptionFailureCount; i++) {
+                        decrypted.push({
+                            session_id: keys[i],
+                        } as unknown as Mocked<IMegolmSessionData>);
+                    }
+                    return decrypted;
+                }),
+                free: jest.fn(),
+            };
+
+            // @ts-ignore - mock a private method for testing purpose
+            aliceCrypto.getBackupDecryptor = jest.fn().mockResolvedValue(mockDecryptor);
+
+            const { response, expectedTotal } = createBackupDownloadResponse([100]);
+
+            fetchMock.get("express:/_matrix/client/v3/room_keys/keys", response);
+
+            const check = await aliceCrypto.checkKeyBackupAndEnable();
+
+            const result = await aliceClient.restoreKeyBackupWithRecoveryKey(
+                testData.BACKUP_DECRYPTION_KEY_BASE58,
+                undefined,
+                undefined,
+                check!.backupInfo!,
+            );
+
+            expect(result.total).toStrictEqual(expectedTotal);
+            // A chunk failed to import
+            expect(result.imported).toStrictEqual(expectedTotal - decryptionFailureCount);
+        });
+
        it("recover specific session from backup", async function () {
-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);
-
-            aliceClient = await initTestClient();
-            const aliceCrypto = aliceClient.getCrypto()!;
-            await aliceClient.startClient();
-
-            // tell Alice to trust the dummy device that signed the backup
-            await waitForDeviceList();
-            await aliceCrypto.setDeviceVerified(testData.TEST_USER_ID, testData.TEST_DEVICE_ID);
-
            fetchMock.get(
                "express:/_matrix/client/v3/room_keys/keys/:room_id/:session_id",
                testData.CURVE25519_KEY_BACKUP_DATA,
@@ -371,16 +548,6 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
        });

        it("Fails on bad recovery key", async function () {
-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);
-
-            aliceClient = await initTestClient();
-            const aliceCrypto = aliceClient.getCrypto()!;
-            await aliceClient.startClient();
-
-            // tell Alice to trust the dummy device that signed the backup
-            await waitForDeviceList();
-            await aliceCrypto.setDeviceVerified(testData.TEST_USER_ID, testData.TEST_DEVICE_ID);
-
            const fullBackup = {
                rooms: {
                    [ROOM_ID]: {
@@ -16,8 +16,12 @@ limitations under the License.

 import "fake-indexeddb/auto";
 import { IDBFactory } from "fake-indexeddb";
+import fetchMock from "fetch-mock-jest";

-import { createClient } from "../../../src";
+import { createClient, CryptoEvent, IndexedDBCryptoStore } from "../../../src";
+import { populateStore } from "../../test-utils/test_indexeddb_cryptostore_dump";
+
+jest.setTimeout(15000);

 afterEach(() => {
    // reset fake-indexeddb after each test, to make sure we don't leak connections
@@ -88,6 +92,151 @@ describe("MatrixClient.initRustCrypto", () => {
        await matrixClient.initRustCrypto();
        await matrixClient.initRustCrypto();
    });
+
+    it("should migrate from libolm", async () => {
+        fetchMock.get("path:/_matrix/client/v3/room_keys/version", {
+            auth_data: {
+                public_key: "q+HZiJdHl2Yopv9GGvv7EYSzDMrAiRknK4glSdoaomI",
+                signatures: {
+                    "@vdhtest200713:matrix.org": {
+                        "ed25519:gh9fGr39eNZUdWynEMJ/q/WZq/Pk/foFxHXFBFm18ZI":
+                            "reDp6Mu+j+tfUL3/T6f5OBT3N825Lzpc43vvG+RvjX6V+KxXzodBQArgCoeEHLtL9OgSBmNrhTkSOX87MWCKAw",
+                        "ed25519:KMFSTJSMLB":
+                            "F8tyV5W6wNi0GXTdSg+gxSCULQi0EYxdAAqfkyNq58KzssZMw5i+PRA0aI2b+D7NH/aZaJrtiYNHJ0gWLSQvAw",
+                    },
+                },
+            },
+            version: "7",
+            algorithm: "m.megolm_backup.v1.curve25519-aes-sha2",
+            etag: "1",
+            count: 79,
+        });
+
+        fetchMock.post("path:/_matrix/client/v3/keys/query", {
+            device_keys: {
+                "@vdhtest200713:matrix.org": {
+                    KMFSTJSMLB: {
+                        algorithms: ["m.olm.v1.curve25519-aes-sha2", "m.megolm.v1.aes-sha2"],
+                        device_id: "KMFSTJSMLB",
+                        keys: {
+                            "curve25519:KMFSTJSMLB": "LKv0bKbc0EC4h0jknbemv3QalEkeYvuNeUXVRgVVTTU",
+                            "ed25519:KMFSTJSMLB": "qK70DEqIXq7T+UU3v/al47Ab4JkMEBLpNrTBMbS5rrw",
+                        },
+                        user_id: "@vdhtest200713:matrix.org",
+                        signatures: {
+                            "@vdhtest200713:matrix.org": {
+                                "ed25519:KMFSTJSMLB":
+                                    "aE+PdxLAdwQ/xfJwLmqebvt/lrT97fZas2SQFFrM+dPmHxQtjyS8csm88BLfGRjJKK1B/vWev3AaKqQZwLTUAw",
+                                "ed25519:lDvg6vi3P80L9XFNpUSU+5Y87m3p6yHcC83jhSU4Q5k":
+                                    "lCd4SA/JT1nnxsgN9yQaLJQhH5hkLMVVx6ba5JAjL1wpWVqyPxzMJHImX6vTztk6S8rybcdfYkea5W/Ii+4HCQ",
+                            },
+                        },
+                    },
+                },
+            },
+            master_keys: {
+                "@vdhtest200713:matrix.org": {
+                    user_id: "@vdhtest200713:matrix.org",
+                    usage: ["master"],
+                    keys: {
+                        "ed25519:gh9fGr39eNZUdWynEMJ/q/WZq/Pk/foFxHXFBFm18ZI":
+                            "gh9fGr39eNZUdWynEMJ/q/WZq/Pk/foFxHXFBFm18ZI",
+                    },
+                    signatures: {
+                        "@vdhtest200713:matrix.org": {
+                            "ed25519:MWOGVUTXZN":
+                                "stOu1aHbhsWB/Aj5M/HqBR83QzME+682C995Uc8JxSmmyrlWmgG8QrnoUDG2OFR1t6zNQ+QLEilU4WNEOV73DQ",
+                        },
+                    },
+                },
+            },
+            self_signing_keys: {
+                "@vdhtest200713:matrix.org": {
+                    user_id: "@vdhtest200713:matrix.org",
+                    usage: ["self_signing"],
+                    keys: {
+                        "ed25519:lDvg6vi3P80L9XFNpUSU+5Y87m3p6yHcC83jhSU4Q5k":
+                            "lDvg6vi3P80L9XFNpUSU+5Y87m3p6yHcC83jhSU4Q5k",
+                    },
+                    signatures: {
+                        "@vdhtest200713:matrix.org": {
+                            "ed25519:gh9fGr39eNZUdWynEMJ/q/WZq/Pk/foFxHXFBFm18ZI":
+                                "HKTC7NoBhAkfJtmemmkn/HvCCgBQViWZ0uH7aGPRaWMDFgD8T7Q+y1j3FKZv4mhSopR85Fq3FRyXsG8OVvGeBA",
+                        },
+                    },
+                },
+            },
+            user_signing_keys: {
+                "@vdhtest200713:matrix.org": {
+                    user_id: "@vdhtest200713:matrix.org",
+                    usage: ["user_signing"],
+                    keys: {
+                        "ed25519:YShqO/3u5vQ0uucojraWrtoLrek0CYrurN/vH/YPMg8":
+                            "YShqO/3u5vQ0uucojraWrtoLrek0CYrurN/vH/YPMg8",
+                    },
+                    signatures: {
+                        "@vdhtest200713:matrix.org": {
+                            "ed25519:gh9fGr39eNZUdWynEMJ/q/WZq/Pk/foFxHXFBFm18ZI":
+                                "u8VOi4IaeRJwDgy2ftK02NJQPdBijy8f/0+WnHGG72yfOvMthwWzEw8SrRSNG8glBNrfHinKwCyJJzAJwyepCQ",
+                        },
+                    },
+                },
+            },
+        });
+
+        const testStoreName = "test-store";
+        await populateStore(testStoreName);
+        const cryptoStore = new IndexedDBCryptoStore(indexedDB, testStoreName);
+
+        const matrixClient = createClient({
+            baseUrl: "http://test.server",
+            userId: "@vdhtest200713:matrix.org",
+            deviceId: "KMFSTJSMLB",
+            cryptoStore,
+            pickleKey: "+1k2Ppd7HIisUY824v7JtV3/oEE4yX0TqtmNPyhaD7o",
+        });
+
+        const progressListener = jest.fn();
+        matrixClient.addListener(CryptoEvent.LegacyCryptoStoreMigrationProgress, progressListener);
+
+        await matrixClient.initRustCrypto();
+
+        const verificationStatus = await matrixClient
+            .getCrypto()!
+            .getDeviceVerificationStatus("@vdhtest200713:matrix.org", "KMFSTJSMLB");
+
+        // Check that the current device and identity trust is migrated correctly just after migration
+        expect(verificationStatus).toBeDefined();
+        expect(verificationStatus!.crossSigningVerified).toEqual(true);
+        expect(verificationStatus!.signedByOwner).toEqual(true);
+
+        // Do some basic checks on the imported data
+        const deviceKeys = await matrixClient.getCrypto()!.getOwnDeviceKeys();
+        expect(deviceKeys.curve25519).toEqual("LKv0bKbc0EC4h0jknbemv3QalEkeYvuNeUXVRgVVTTU");
+        expect(deviceKeys.ed25519).toEqual("qK70DEqIXq7T+UU3v/al47Ab4JkMEBLpNrTBMbS5rrw");
+
+        expect(await matrixClient.getCrypto()!.getActiveSessionBackupVersion()).toEqual("7");
+
+        expect(await matrixClient.getCrypto()!.isEncryptionEnabledInRoom("!CWLUCoEWXSFyTCOtfL:matrix.org")).toBe(true);
+
+        // check the progress callback
+        expect(progressListener.mock.calls.length).toBeGreaterThan(50);
+
+        // The first call should have progress == 0
+        const [firstProgress, totalSteps] = progressListener.mock.calls[0];
+        expect(totalSteps).toBeGreaterThan(3000);
+        expect(firstProgress).toEqual(0);
+
+        for (let i = 1; i < progressListener.mock.calls.length - 1; i++) {
+            const [progress, total] = progressListener.mock.calls[i];
+            expect(total).toEqual(totalSteps);
+            expect(progress).toBeGreaterThan(progressListener.mock.calls[i - 1][0]);
+            expect(progress).toBeLessThanOrEqual(totalSteps);
+        }
+
+        // The final call should have progress == total == -1
+        expect(progressListener).toHaveBeenLastCalledWith(-1, -1);
+    }, 60000);
 });

 describe("MatrixClient.clearStores", () => {
@@ -85,7 +85,8 @@ import { encodeBase64 } from "../../../src/base64";

 // The verification flows use javascript timers to set timeouts. We tell jest to use mock timer implementations
 // to ensure that we don't end up with dangling timeouts.
-jest.useFakeTimers();
+// But the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
+jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });

 beforeAll(async () => {
    // we use the libolm primitives in the test, so init the Olm library
@@ -743,6 +744,8 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
            expect(toDeviceMessage.transaction_id).toEqual(transactionId);
            expect(toDeviceMessage.code).toEqual("m.user");
            expect(request.phase).toEqual(VerificationPhase.Cancelled);
+            expect(request.cancellationCode).toEqual("m.user");
+            expect(request.cancellingUserId).toEqual("@alice:localhost");
        });

        it("can cancel during the SAS phase", async () => {
@@ -1285,7 +1288,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
            await new Promise((resolve) => {
                setTimeout(resolve, 500);
            });
-            jest.useFakeTimers();
+            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });

            // the backup secret should not be cached
            const cachedKey = await aliceClient.getCrypto()!.getSessionBackupPrivateKey();
@@ -1309,7 +1312,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
            await new Promise((resolve) => {
                setTimeout(resolve, 500);
            });
-            jest.useFakeTimers();
+            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });

            // the backup secret should not be cached
            const cachedKey = await aliceClient.getCrypto()!.getSessionBackupPrivateKey();
@@ -1334,7 +1337,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
            await new Promise((resolve) => {
                setTimeout(resolve, 500);
            });
-            jest.useFakeTimers();
+            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });

            // the backup secret should not be cached
            const cachedKey = await aliceClient.getCrypto()!.getSessionBackupPrivateKey();
@@ -1355,7 +1358,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
            await new Promise((resolve) => {
                setTimeout(resolve, 500);
            });
-            jest.useFakeTimers();
+            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });

            // the backup secret should not be cached
            const cachedKey = await aliceClient.getCrypto()!.getSessionBackupPrivateKey();
@@ -33,7 +33,7 @@ import {
 import { logger } from "../../src/logger";
 import { encodeParams, encodeUri, QueryDict, replaceParam } from "../../src/utils";
 import { TestClient } from "../TestClient";
-import { FeatureSupport, Thread, THREAD_RELATION_TYPE, ThreadEvent } from "../../src/models/thread";
+import { FeatureSupport, Thread, ThreadEvent } from "../../src/models/thread";
 import { emitPromise } from "../test-utils/test-utils";
 import { Feature, ServerSupport } from "../../src/feature";

@@ -623,9 +623,7 @@ describe("MatrixClient event timelines", function () {
                    "GET",
                    "/rooms/!foo%3Abar/relations/" +
                        encodeURIComponent(THREAD_ROOT.event_id!) +
-                        "/" +
-                        encodeURIComponent(THREAD_RELATION_TYPE.name) +
-                        buildRelationPaginationQuery({ dir: Direction.Backward, limit: 1 }),
+                        buildRelationPaginationQuery({ dir: Direction.Backward }),
                )
                .respond(200, function () {
                    return {
@@ -1154,10 +1152,7 @@ describe("MatrixClient event timelines", function () {
        httpBackend
            .when(
                "GET",
-                "/_matrix/client/v1/rooms/!foo%3Abar/relations/" +
-                    encodeURIComponent(THREAD_ROOT_UPDATED.event_id!) +
-                    "/" +
-                    encodeURIComponent(THREAD_RELATION_TYPE.name),
+                "/_matrix/client/v1/rooms/!foo%3Abar/relations/" + encodeURIComponent(THREAD_ROOT_UPDATED.event_id!),
            )
            .respond(200, {
                chunk: [THREAD_REPLY3.event, THREAD_REPLY2.event, THREAD_REPLY],
@@ -1262,11 +1257,8 @@ describe("MatrixClient event timelines", function () {
                "GET",
                "/_matrix/client/v1/rooms/!foo%3Abar/relations/" +
                    encodeURIComponent(THREAD_ROOT_UPDATED.event_id!) +
-                    "/" +
-                    encodeURIComponent(THREAD_RELATION_TYPE.name) +
                    buildRelationPaginationQuery({
                        dir: Direction.Backward,
-                        limit: 3,
                        recurse: true,
                    }),
            )
@@ -1321,11 +1313,7 @@ describe("MatrixClient event timelines", function () {
        function respondToThread(root: Partial<IEvent>, replies: Partial<IEvent>[]): ExpectedHttpRequest {
            const request = httpBackend.when(
                "GET",
-                "/_matrix/client/v1/rooms/!foo%3Abar/relations/" +
-                    encodeURIComponent(root.event_id!) +
-                    "/" +
-                    encodeURIComponent(THREAD_RELATION_TYPE.name) +
-                    "?dir=b&limit=1",
+                "/_matrix/client/v1/rooms/!foo%3Abar/relations/" + encodeURIComponent(root.event_id!) + "?dir=b",
            );
            request.respond(200, function () {
                return {
@@ -1567,7 +1555,7 @@ describe("MatrixClient event timelines", function () {
                expect(threadIds).toContain(THREAD2_ROOT.event_id);
                const [allThreads] = timelineSets!;
                const timeline = allThreads.getLiveTimeline()!;
-                // Test threads are in chronological order
+                // Test threads are in chronological order (first thread should be first because it has a more recent reply)
                expect(timeline.getEvents().map((it) => it.event.event_id)).toEqual([
                    THREAD_ROOT.event_id,
                    THREAD2_ROOT.event_id,
@@ -2034,9 +2022,7 @@ describe("MatrixClient event timelines", function () {
                    "GET",
                    "/_matrix/client/v1/rooms/!foo%3Abar/relations/" +
                        encodeURIComponent(THREAD_ROOT.event_id!) +
-                        "/" +
-                        encodeURIComponent(THREAD_RELATION_TYPE.name) +
-                        buildRelationPaginationQuery({ dir: Direction.Backward, limit: 1 }),
+                        buildRelationPaginationQuery({ dir: Direction.Backward }),
                )
                .respond(200, function () {
                    return {
@@ -24,11 +24,21 @@ import { KeyBackupInfo } from "../../src/crypto-api";
 * @param homeserverUrl - the homeserver url for the client under test
 */
 export function mockInitialApiRequests(homeserverUrl: string) {
-    fetchMock.getOnce(new URL("/_matrix/client/versions", homeserverUrl).toString(), { versions: ["v1.1"] });
-    fetchMock.getOnce(new URL("/_matrix/client/v3/pushrules/", homeserverUrl).toString(), {});
-    fetchMock.postOnce(new URL("/_matrix/client/v3/user/%40alice%3Alocalhost/filter", homeserverUrl).toString(), {
-        filter_id: "fid",
-    });
+    fetchMock.getOnce(
+        new URL("/_matrix/client/versions", homeserverUrl).toString(),
+        { versions: ["v1.1"] },
+        { overwriteRoutes: true },
+    );
+    fetchMock.getOnce(
+        new URL("/_matrix/client/v3/pushrules/", homeserverUrl).toString(),
+        {},
+        { overwriteRoutes: true },
+    );
+    fetchMock.postOnce(
+        new URL("/_matrix/client/v3/user/%40alice%3Alocalhost/filter", homeserverUrl).toString(),
+        { filter_id: "fid" },
+        { overwriteRoutes: true },
+    );
 }

 /**
@@ -14,8 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import { OidcClientConfig } from "../../src";
-import { ValidatedIssuerMetadata } from "../../src/oidc/validate";
+import { OidcClientConfig, ValidatedIssuerMetadata } from "../../src";

 /**
 * Makes a valid OidcClientConfig with minimum valid values
@@ -26,8 +25,7 @@ export const makeDelegatedAuthConfig = (issuer = "https://auth.org/"): OidcClien
    const metadata = mockOpenIdConfiguration(issuer);

    return {
-        issuer,
-        account: issuer + "account",
+        accountManagementEndpoint: issuer + "account",
        registrationEndpoint: metadata.registration_endpoint,
        authorizationEndpoint: metadata.authorization_endpoint,
        tokenEndpoint: metadata.token_endpoint,
@@ -0,0 +1,53 @@
+## Dump of libolm indexeddb cryptostore
+
+This directory contains a dump of a real indexeddb store from a session using
+libolm crypto.
+
+The corresponding pickle key is `+1k2Ppd7HIisUY824v7JtV3/oEE4yX0TqtmNPyhaD7o`.
+
+It was created by pasting the following into the browser console:
+
+```javascript
+async function exportIndexedDb(name) {
+    const db = await new Promise((resolve, reject) => {
+        const dbReq = indexedDB.open(name);
+        dbReq.onerror = reject;
+        dbReq.onsuccess = () => resolve(dbReq.result);
+    });
+
+    const storeNames = db.objectStoreNames;
+    const exports = {};
+    for (const store of storeNames) {
+        exports[store] = [];
+        const txn = db.transaction(store, "readonly");
+        const objectStore = txn.objectStore(store);
+        await new Promise((resolve, reject) => {
+            const cursorReq = objectStore.openCursor();
+            cursorReq.onerror = reject;
+            cursorReq.onsuccess = (event) => {
+                const cursor = event.target.result;
+                if (cursor) {
+                    const entry = { value: cursor.value };
+                    if (!objectStore.keyPath) {
+                        entry.key = cursor.key;
+                    }
+                    exports[store].push(entry);
+                    cursor.continue();
+                } else {
+                    resolve();
+                }
+            };
+        });
+    }
+    return exports;
+}
+
+window.saveAs(
+    new Blob([JSON.stringify(await exportIndexedDb("matrix-js-sdk:crypto"), null, 2)], {
+        type: "application/json;charset=utf-8",
+    }),
+    "dump.json",
+);
+```
+
+The pickle key is extracted via `mxMatrixClientPeg.get().crypto.olmDevice.pickleKey`.
@@ -0,0 +1,136 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { readFile } from "node:fs/promises";
+import { resolve } from "node:path";
+
+/**
+ * Populate an IndexedDB store with the test data from this directory.
+ *
+ * @param name - Name of the IndexedDB database to create.
+ */
+export async function populateStore(name: string): Promise<IDBDatabase> {
+    const req = indexedDB.open(name, 11);
+
+    const db = await new Promise<IDBDatabase>((resolve, reject) => {
+        req.onupgradeneeded = (ev): void => {
+            const db = req.result;
+            const oldVersion = ev.oldVersion;
+            upgradeDatabase(oldVersion, db);
+        };
+
+        req.onerror = (ev): void => {
+            reject(req.error);
+        };
+
+        req.onsuccess = (): void => {
+            const db = req.result;
+            resolve(db);
+        };
+    });
+
+    await importData(db);
+
+    return db;
+}
+
+/** Create the schema for the indexed db store */
+function upgradeDatabase(oldVersion: number, db: IDBDatabase) {
+    if (oldVersion < 1) {
+        const outgoingRoomKeyRequestsStore = db.createObjectStore("outgoingRoomKeyRequests", { keyPath: "requestId" });
+        outgoingRoomKeyRequestsStore.createIndex("session", ["requestBody.room_id", "requestBody.session_id"]);
+        outgoingRoomKeyRequestsStore.createIndex("state", "state");
+    }
+
+    if (oldVersion < 2) {
+        db.createObjectStore("account");
+    }
+
+    if (oldVersion < 3) {
+        const sessionsStore = db.createObjectStore("sessions", { keyPath: ["deviceKey", "sessionId"] });
+        sessionsStore.createIndex("deviceKey", "deviceKey");
+    }
+
+    if (oldVersion < 4) {
+        db.createObjectStore("inbound_group_sessions", { keyPath: ["senderCurve25519Key", "sessionId"] });
+    }
+
+    if (oldVersion < 5) {
+        db.createObjectStore("device_data");
+    }
+
+    if (oldVersion < 6) {
+        db.createObjectStore("rooms");
+    }
+
+    if (oldVersion < 7) {
+        db.createObjectStore("sessions_needing_backup", { keyPath: ["senderCurve25519Key", "sessionId"] });
+    }
+
+    if (oldVersion < 8) {
+        db.createObjectStore("inbound_group_sessions_withheld", { keyPath: ["senderCurve25519Key", "sessionId"] });
+    }
+
+    if (oldVersion < 9) {
+        const problemsStore = db.createObjectStore("session_problems", { keyPath: ["deviceKey", "time"] });
+        problemsStore.createIndex("deviceKey", "deviceKey");
+
+        db.createObjectStore("notified_error_devices", { keyPath: ["userId", "deviceId"] });
+    }
+
+    if (oldVersion < 10) {
+        db.createObjectStore("shared_history_inbound_group_sessions", { keyPath: ["roomId"] });
+    }
+
+    if (oldVersion < 11) {
+        db.createObjectStore("parked_shared_history", { keyPath: ["roomId"] });
+    }
+}
+
+async function importData(db: IDBDatabase) {
+    const path = resolve("spec/test-utils/test_indexeddb_cryptostore_dump/dump.json");
+    const json: Record<string, Array<{ key?: any; value: any }>> = JSON.parse(
+        await readFile(path, { encoding: "utf8" }),
+    );
+
+    for (const [storeName, data] of Object.entries(json)) {
+        await new Promise((resolve, reject) => {
+            const store = db.transaction(storeName, "readwrite").objectStore(storeName);
+
+            function putEntry(idx: number) {
+                if (idx >= data.length) {
+                    resolve(undefined);
+                    return;
+                }
+
+                const { key, value } = data[idx];
+                try {
+                    const putReq = store.put(value, key);
+                    putReq.onsuccess = (_) => putEntry(idx + 1);
+                    putReq.onerror = (_) => reject(putReq.error);
+                } catch (e) {
+                    throw new Error(
+                        `Error populating '${storeName}' with key ${JSON.stringify(key)}, value ${JSON.stringify(
+                            value,
+                        )}: ${e}`,
+                    );
+                }
+            }
+
+            putEntry(0);
+        });
+    }
+}
@@ -269,7 +269,11 @@ export class MockRTCRtpTransceiver {
 }

 export class MockMediaStreamTrack {
-    constructor(public readonly id: string, public readonly kind: "audio" | "video", public enabled = true) {}
+    constructor(
+        public readonly id: string,
+        public readonly kind: "audio" | "video",
+        public enabled = true,
+    ) {}

    public stop = jest.fn<void, []>();

@@ -306,7 +310,10 @@ export class MockMediaStreamTrack {
 // XXX: Using EventTarget in jest doesn't seem to work, so we write our own
 // implementation
 export class MockMediaStream {
-    constructor(public id: string, private tracks: MockMediaStreamTrack[] = []) {}
+    constructor(
+        public id: string,
+        private tracks: MockMediaStreamTrack[] = [],
+    ) {}

    public listeners: [string, (...args: any[]) => any][] = [];
    public isStopped = false;
@@ -435,7 +442,11 @@ type EmittedEventMap = CallEventHandlerEventHandlerMap &
 export class MockCallMatrixClient extends TypedEventEmitter<EmittedEvents, EmittedEventMap> {
    public mediaHandler = new MockMediaHandler();

-    constructor(public userId: string, public deviceId: string, public sessionId: string) {
+    constructor(
+        public userId: string,
+        public deviceId: string,
+        public sessionId: string,
+    ) {
        super();
    }

@@ -502,7 +513,10 @@ export class MockCallMatrixClient extends TypedEventEmitter<EmittedEvents, Emitt
 }

 export class MockMatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap> {
-    constructor(public roomId: string, public groupCallId?: string) {
+    constructor(
+        public roomId: string,
+        public groupCallId?: string,
+    ) {
        super();
    }

@@ -550,7 +564,11 @@ export class MockMatrixCall extends TypedEventEmitter<CallEvent, CallEventHandle
 }

 export class MockCallFeed {
-    constructor(public userId: string, public deviceId: string | undefined, public stream: MockMediaStream) {}
+    constructor(
+        public userId: string,
+        public deviceId: string | undefined,
+        public stream: MockMediaStream,
+    ) {}

    public measureVolumeActivity(val: boolean) {}
    public dispose() {}
@@ -15,13 +15,10 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import fetchMock from "fetch-mock-jest";
 import MockHttpBackend from "matrix-mock-request";

-import { AutoDiscoveryAction, M_AUTHENTICATION } from "../../src";
+import { AutoDiscoveryAction } from "../../src";
 import { AutoDiscovery } from "../../src/autodiscovery";
-import { OidcError } from "../../src/oidc/error";
-import { makeDelegatedAuthConfig } from "../test-utils/oidc";

 // keep to reset the fetch function after using MockHttpBackend
 // @ts-ignore private property
@@ -351,7 +348,7 @@ describe("AutoDiscovery", function () {
        function () {
            const httpBackend = getHttpBackend();
            httpBackend.when("GET", "/_matrix/client/versions").respond(200, {
-                not_matrix_versions: ["v1.1"],
+                not_matrix_versions: ["v1.5"],
            });
            httpBackend.when("GET", "/.well-known/matrix/client").respond(200, {
                "m.homeserver": {
@@ -388,7 +385,7 @@ describe("AutoDiscovery", function () {
                expect(req.path).toEqual("https://example.org/_matrix/client/versions");
            })
            .respond(200, {
-                versions: ["v1.1"],
+                versions: ["v1.5"],
            });
        httpBackend.when("GET", "/.well-known/matrix/client").respond(200, {
            "m.homeserver": {
@@ -409,10 +406,6 @@ describe("AutoDiscovery", function () {
                        error: null,
                        base_url: null,
                    },
-                    "m.authentication": {
-                        state: "IGNORE",
-                        error: OidcError.NotSupported,
-                    },
                };

                expect(conf).toEqual(expected);
@@ -428,7 +421,7 @@ describe("AutoDiscovery", function () {
                expect(req.path).toEqual("https://chat.example.org/_matrix/client/versions");
            })
            .respond(200, {
-                versions: ["v1.1"],
+                versions: ["v1.5"],
            });
        httpBackend.when("GET", "/.well-known/matrix/client").respond(200, {
            "m.homeserver": {
@@ -450,10 +443,6 @@ describe("AutoDiscovery", function () {
                        error: null,
                        base_url: null,
                    },
-                    "m.authentication": {
-                        state: "IGNORE",
-                        error: OidcError.NotSupported,
-                    },
                };

                expect(conf).toEqual(expected);
@@ -469,16 +458,13 @@ describe("AutoDiscovery", function () {
                expect(req.path).toEqual("https://chat.example.org/_matrix/client/versions");
            })
            .respond(200, {
-                versions: ["v1.1"],
+                versions: ["v1.5"],
            });
        httpBackend.when("GET", "/.well-known/matrix/client").respond(200, {
            "m.homeserver": {
                // Note: we also expect this test to trim the trailing slash
                base_url: "https://chat.example.org/",
            },
-            "m.authentication": {
-                invalid: true,
-            },
        });
        return Promise.all([
            httpBackend.flushAllExpected(),
@@ -494,10 +480,6 @@ describe("AutoDiscovery", function () {
                        error: null,
                        base_url: null,
                    },
-                    "m.authentication": {
-                        state: "FAIL_ERROR",
-                        error: OidcError.Misconfigured,
-                    },
                };

                expect(conf).toEqual(expected);
@@ -515,7 +497,7 @@ describe("AutoDiscovery", function () {
                    expect(req.path).toEqual("https://chat.example.org/_matrix/client/versions");
                })
                .respond(200, {
-                    versions: ["v1.1"],
+                    versions: ["v1.5"],
                });
            httpBackend.when("GET", "/.well-known/matrix/client").respond(200, {
                "m.homeserver": {
@@ -560,7 +542,7 @@ describe("AutoDiscovery", function () {
                    expect(req.path).toEqual("https://chat.example.org/_matrix/client/versions");
                })
                .respond(200, {
-                    versions: ["v1.1"],
+                    versions: ["v1.5"],
                });
            httpBackend.when("GET", "/.well-known/matrix/client").respond(200, {
                "m.homeserver": {
@@ -606,7 +588,7 @@ describe("AutoDiscovery", function () {
                    expect(req.path).toEqual("https://chat.example.org/_matrix/client/versions");
                })
                .respond(200, {
-                    versions: ["v1.1"],
+                    versions: ["v1.5"],
                });
            httpBackend.when("GET", "/_matrix/identity/v2").respond(404, {});
            httpBackend.when("GET", "/.well-known/matrix/client").respond(200, {
@@ -653,7 +635,7 @@ describe("AutoDiscovery", function () {
                    expect(req.path).toEqual("https://chat.example.org/_matrix/client/versions");
                })
                .respond(200, {
-                    versions: ["v1.1"],
+                    versions: ["v1.5"],
                });
            httpBackend.when("GET", "/_matrix/identity/v2").respond(500, {});
            httpBackend.when("GET", "/.well-known/matrix/client").respond(200, {
@@ -697,7 +679,7 @@ describe("AutoDiscovery", function () {
                expect(req.path).toEqual("https://chat.example.org/_matrix/client/versions");
            })
            .respond(200, {
-                versions: ["v1.1"],
+                versions: ["v1.5"],
            });
        httpBackend
            .when("GET", "/_matrix/identity/v2")
@@ -728,10 +710,6 @@ describe("AutoDiscovery", function () {
                        error: null,
                        base_url: "https://identity.example.org",
                    },
-                    "m.authentication": {
-                        state: "IGNORE",
-                        error: OidcError.NotSupported,
-                    },
                };

                expect(conf).toEqual(expected);
@@ -747,7 +725,7 @@ describe("AutoDiscovery", function () {
                expect(req.path).toEqual("https://chat.example.org/_matrix/client/versions");
            })
            .respond(200, {
-                versions: ["v1.1"],
+                versions: ["v1.5"],
            });
        httpBackend
            .when("GET", "/_matrix/identity/v2")
@@ -784,10 +762,6 @@ describe("AutoDiscovery", function () {
                    "org.example.custom.property": {
                        cupcakes: "yes",
                    },
-                    "m.authentication": {
-                        state: "IGNORE",
-                        error: OidcError.NotSupported,
-                    },
                };

                expect(conf).toEqual(expected);
@@ -897,75 +871,4 @@ describe("AutoDiscovery", function () {
            }),
        ]);
    });
-
-    describe("m.authentication", () => {
-        const homeserverName = "example.org";
-        const homeserverUrl = "https://chat.example.org/";
-        const issuer = "https://auth.org/";
-
-        beforeAll(() => {
-            // make these tests independent from fetch mocking above
-            AutoDiscovery.setFetchFn(realAutoDiscoveryFetch);
-        });
-
-        beforeEach(() => {
-            fetchMock.resetBehavior();
-            fetchMock.get(`${homeserverUrl}_matrix/client/versions`, { versions: ["v1.1"] });
-
-            fetchMock.get("https://example.org/.well-known/matrix/client", {
-                "m.homeserver": {
-                    // Note: we also expect this test to trim the trailing slash
-                    base_url: "https://chat.example.org/",
-                },
-                "m.authentication": {
-                    issuer,
-                },
-            });
-        });
-
-        it("should return valid authentication configuration", async () => {
-            const config = makeDelegatedAuthConfig(issuer);
-
-            fetchMock.get(`${config.metadata.issuer}.well-known/openid-configuration`, config.metadata);
-            fetchMock.get(`${config.metadata.issuer}jwks`, {
-                status: 200,
-                headers: {
-                    "Content-Type": "application/json",
-                },
-                keys: [],
-            });
-
-            const result = await AutoDiscovery.findClientConfig(homeserverName);
-
-            expect(result[M_AUTHENTICATION.stable!]).toEqual({
-                state: AutoDiscovery.SUCCESS,
-                ...config,
-                signingKeys: [],
-                account: undefined,
-                error: null,
-            });
-        });
-
-        it("should set state to error for invalid authentication configuration", async () => {
-            const config = makeDelegatedAuthConfig(issuer);
-            // authorization_code is required
-            config.metadata.grant_types_supported = ["openid"];
-
-            fetchMock.get(`${config.metadata.issuer}.well-known/openid-configuration`, config.metadata);
-            fetchMock.get(`${config.metadata.issuer}jwks`, {
-                status: 200,
-                headers: {
-                    "Content-Type": "application/json",
-                },
-                keys: [],
-            });
-
-            const result = await AutoDiscovery.findClientConfig(homeserverName);
-
-            expect(result[M_AUTHENTICATION.stable!]).toEqual({
-                state: AutoDiscovery.FAIL_ERROR,
-                error: OidcError.OpSupport,
-            });
-        });
-    });
 });
@@ -37,6 +37,21 @@ describe("ContentRepo", function () {
            );
        });

+        it("should allow redirects when requested on download URLs", function () {
+            const mxcUri = "mxc://server.name/resourceid";
+            expect(getHttpUriForMxc(baseUrl, mxcUri, undefined, undefined, undefined, false, true)).toEqual(
+                baseUrl + "/_matrix/media/v3/download/server.name/resourceid?allow_redirect=true",
+            );
+        });
+
+        it("should allow redirects when requested on thumbnail URLs", function () {
+            const mxcUri = "mxc://server.name/resourceid";
+            expect(getHttpUriForMxc(baseUrl, mxcUri, 32, 32, "scale", false, true)).toEqual(
+                baseUrl +
+                    "/_matrix/media/v3/thumbnail/server.name/resourceid?width=32&height=32&method=scale&allow_redirect=true",
+            );
+        });
+
        it("should return the empty string for null input", function () {
            expect(getHttpUriForMxc(null as any, "")).toEqual("");
        });
@@ -1263,7 +1263,7 @@ describe("Crypto", function () {
                    ({
                        init_with_private_key: jest.fn(),
                        free,
-                    } as unknown as PkDecryption),
+                    }) as unknown as PkDecryption,
            );
            client.client.checkSecretStoragePrivateKey(new Uint8Array(), "");
            expect(free).toHaveBeenCalled();
@@ -1289,7 +1289,7 @@ describe("Crypto", function () {
                    ({
                        init_with_seed: jest.fn(),
                        free,
-                    } as unknown as PkSigning),
+                    }) as unknown as PkSigning,
            );
            client.client.checkCrossSigningPrivateKey(new Uint8Array(), "");
            expect(free).toHaveBeenCalled();
@@ -106,7 +106,7 @@ describe("Cross Signing", function () {
        });
        alice.uploadKeySignatures = async () => ({ failures: {} });
        alice.setAccountData = async () => ({});
-        alice.getAccountDataFromServer = async <T>() => ({} as T);
+        alice.getAccountDataFromServer = async <T>() => ({}) as T;
        // set Alice's cross-signing key
        await alice.bootstrapCrossSigning({
            authUploadDeviceSigningKeys: async (func) => {
@@ -146,7 +146,7 @@ describe("Cross Signing", function () {
        };
        alice.uploadKeySignatures = async () => ({ failures: {} });
        alice.setAccountData = async () => ({});
-        alice.getAccountDataFromServer = async <T extends { [k: string]: any }>(): Promise<T | null> => ({} as T);
+        alice.getAccountDataFromServer = async <T extends { [k: string]: any }>(): Promise<T | null> => ({}) as T;
        const authUploadDeviceSigningKeys: BootstrapCrossSigningOpts["authUploadDeviceSigningKeys"] = async (func) => {
            await func({});
        };
@@ -33,12 +33,10 @@ export async function resetCrossSigningKeys(

 export async function createSecretStorageKey(): Promise<IRecoveryKey> {
    const decryption = new global.Olm.PkDecryption();
-    const storagePublicKey = decryption.generate_key();
+    decryption.generate_key();
    const storagePrivateKey = decryption.get_private_key();
    decryption.free();
    return {
-        // `pubkey` not used anymore with symmetric 4S
-        keyInfo: { pubkey: storagePublicKey, key: undefined! },
        privateKey: storagePrivateKey,
    };
 }
@@ -190,10 +190,7 @@ describe("Secrets", function () {
        };
        resetCrossSigningKeys(alice);

-        const { keyId: newKeyId } = await alice.addSecretStorageKey(SECRET_STORAGE_ALGORITHM_V1_AES, {
-            pubkey: undefined,
-            key: undefined,
-        });
+        const { keyId: newKeyId } = await alice.addSecretStorageKey(SECRET_STORAGE_ALGORITHM_V1_AES, { key });
        // we don't await on this because it waits for the event to come down the sync
        // which won't happen in the test setup
        alice.setDefaultSecretStorageKeyId(newKeyId);
@@ -335,7 +332,6 @@ describe("Secrets", function () {

        it("bootstraps when cross-signing keys in secret storage", async function () {
            const decryption = new global.Olm.PkDecryption();
-            const storagePublicKey = decryption.generate_key();
            const storagePrivateKey = decryption.get_private_key();

            const bob: MatrixClient = await makeTestClient(
@@ -378,8 +374,6 @@ describe("Secrets", function () {
            });
            await bob.bootstrapSecretStorage({
                createSecretStorageKey: async () => ({
-                    // `pubkey` not used anymore with symmetric 4S
-                    keyInfo: { pubkey: storagePublicKey },
                    privateKey: storagePrivateKey,
                }),
            });
@@ -0,0 +1,226 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import "fake-indexeddb/auto";
+import "jest-localstorage-mock";
+import { IndexedDBCryptoStore, LocalStorageCryptoStore, MemoryCryptoStore } from "../../../../src";
+import { CryptoStore, MigrationState, SESSION_BATCH_SIZE } from "../../../../src/crypto/store/base";
+
+describe.each([
+    ["IndexedDBCryptoStore", () => new IndexedDBCryptoStore(global.indexedDB, "tests")],
+    ["LocalStorageCryptoStore", () => new LocalStorageCryptoStore(localStorage)],
+    ["MemoryCryptoStore", () => new MemoryCryptoStore()],
+])("CryptoStore tests for %s", function (name, dbFactory) {
+    let store: CryptoStore;
+
+    beforeEach(async () => {
+        store = dbFactory();
+    });
+
+    describe("containsData", () => {
+        it("returns false at first", async () => {
+            expect(await store.containsData()).toBe(false);
+        });
+
+        it("returns true after startup and account setup", async () => {
+            await store.startup();
+            await store.doTxn("readwrite", [IndexedDBCryptoStore.STORE_ACCOUNT], (txn) => {
+                store.storeAccount(txn, "not a real account");
+            });
+            expect(await store.containsData()).toBe(true);
+        });
+    });
+
+    describe("migrationState", () => {
+        beforeEach(async () => {
+            await store.startup();
+        });
+
+        it("returns 0 at first", async () => {
+            expect(await store.getMigrationState()).toEqual(MigrationState.NOT_STARTED);
+        });
+
+        it("stores updates", async () => {
+            await store.setMigrationState(MigrationState.INITIAL_DATA_MIGRATED);
+            expect(await store.getMigrationState()).toEqual(MigrationState.INITIAL_DATA_MIGRATED);
+        });
+    });
+
+    describe("get/delete EndToEndSessionsBatch", () => {
+        beforeEach(async () => {
+            await store.startup();
+        });
+
+        it("returns null at first", async () => {
+            expect(await store.getEndToEndSessionsBatch()).toBe(null);
+        });
+
+        it("returns a batch of sessions", async () => {
+            // First store some sessions in the db
+            const N_DEVICES = 6;
+            const N_SESSIONS_PER_DEVICE = 6;
+            await createSessions(N_DEVICES, N_SESSIONS_PER_DEVICE);
+
+            let nSessions = 0;
+            await store.doTxn("readonly", [IndexedDBCryptoStore.STORE_SESSIONS], (txn) =>
+                store.countEndToEndSessions(txn, (n) => (nSessions = n)),
+            );
+            expect(nSessions).toEqual(N_DEVICES * N_SESSIONS_PER_DEVICE);
+
+            // Then, get a batch and check it looks right.
+            const batch = await store.getEndToEndSessionsBatch();
+            expect(batch!.length).toEqual(N_DEVICES * N_SESSIONS_PER_DEVICE);
+            for (let i = 0; i < N_DEVICES; i++) {
+                for (let j = 0; j < N_SESSIONS_PER_DEVICE; j++) {
+                    const r = batch![i * N_DEVICES + j];
+
+                    expect(r.deviceKey).toEqual(`device${i}`);
+                    expect(r.sessionId).toEqual(`session${j}`);
+                }
+            }
+        });
+
+        it("returns another batch of sessions after the first batch is deleted", async () => {
+            // First store some sessions in the db
+            const N_DEVICES = 8;
+            const N_SESSIONS_PER_DEVICE = 8;
+            await createSessions(N_DEVICES, N_SESSIONS_PER_DEVICE);
+
+            // Get the first batch
+            const batch = (await store.getEndToEndSessionsBatch())!;
+            expect(batch.length).toEqual(SESSION_BATCH_SIZE);
+
+            // ... and delete.
+            await store.deleteEndToEndSessionsBatch(batch);
+
+            // Fetch a second batch
+            const batch2 = (await store.getEndToEndSessionsBatch())!;
+            expect(batch2.length).toEqual(N_DEVICES * N_SESSIONS_PER_DEVICE - SESSION_BATCH_SIZE);
+
+            // ... and delete.
+            await store.deleteEndToEndSessionsBatch(batch2);
+
+            // the batch should now be null.
+            expect(await store.getEndToEndSessionsBatch()).toBe(null);
+        });
+
+        /** Create a bunch of fake Olm sessions and stash them in the DB. */
+        async function createSessions(nDevices: number, nSessionsPerDevice: number) {
+            await store.doTxn("readwrite", IndexedDBCryptoStore.STORE_SESSIONS, (txn) => {
+                for (let i = 0; i < nDevices; i++) {
+                    for (let j = 0; j < nSessionsPerDevice; j++) {
+                        store.storeEndToEndSession(
+                            `device${i}`,
+                            `session${j}`,
+                            {
+                                deviceKey: `device${i}`,
+                                sessionId: `session${j}`,
+                            },
+                            txn,
+                        );
+                    }
+                }
+            });
+        }
+    });
+
+    describe("get/delete EndToEndInboundGroupSessionsBatch", () => {
+        beforeEach(async () => {
+            await store.startup();
+        });
+
+        it("returns null at first", async () => {
+            expect(await store.getEndToEndInboundGroupSessionsBatch()).toBe(null);
+        });
+
+        it("returns a batch of sessions", async () => {
+            const N_DEVICES = 6;
+            const N_SESSIONS_PER_DEVICE = 6;
+            await createSessions(N_DEVICES, N_SESSIONS_PER_DEVICE);
+
+            // Mark one of the sessions as needing backup
+            await store.doTxn("readwrite", IndexedDBCryptoStore.STORE_BACKUP, async (txn) => {
+                await store.markSessionsNeedingBackup([{ senderKey: pad43("device5"), sessionId: "session5" }], txn);
+            });
+
+            expect(await store.countEndToEndInboundGroupSessions()).toEqual(N_DEVICES * N_SESSIONS_PER_DEVICE);
+
+            const batch = await store.getEndToEndInboundGroupSessionsBatch();
+            expect(batch!.length).toEqual(N_DEVICES * N_SESSIONS_PER_DEVICE);
+            for (let i = 0; i < N_DEVICES; i++) {
+                for (let j = 0; j < N_SESSIONS_PER_DEVICE; j++) {
+                    const r = batch![i * N_DEVICES + j];
+
+                    expect(r.senderKey).toEqual(pad43(`device${i}`));
+                    expect(r.sessionId).toEqual(`session${j}`);
+
+                    // only the last session needs backup
+                    expect(r.needsBackup).toBe(i === 5 && j === 5);
+                }
+            }
+        });
+
+        it("returns another batch of sessions after the first batch is deleted", async () => {
+            // First store some sessions in the db
+            const N_DEVICES = 8;
+            const N_SESSIONS_PER_DEVICE = 8;
+            await createSessions(N_DEVICES, N_SESSIONS_PER_DEVICE);
+
+            // Get the first batch
+            const batch = (await store.getEndToEndInboundGroupSessionsBatch())!;
+            expect(batch.length).toEqual(SESSION_BATCH_SIZE);
+
+            // ... and delete.
+            await store.deleteEndToEndInboundGroupSessionsBatch(batch);
+
+            // Fetch a second batch
+            const batch2 = (await store.getEndToEndInboundGroupSessionsBatch())!;
+            expect(batch2.length).toEqual(N_DEVICES * N_SESSIONS_PER_DEVICE - SESSION_BATCH_SIZE);
+
+            // ... and delete.
+            await store.deleteEndToEndInboundGroupSessionsBatch(batch2);
+
+            // the batch should now be null.
+            expect(await store.getEndToEndInboundGroupSessionsBatch()).toBe(null);
+        });
+
+        /** Create a bunch of fake megolm sessions and stash them in the DB. */
+        async function createSessions(nDevices: number, nSessionsPerDevice: number) {
+            await store.doTxn("readwrite", IndexedDBCryptoStore.STORE_INBOUND_GROUP_SESSIONS, (txn) => {
+                for (let i = 0; i < nDevices; i++) {
+                    for (let j = 0; j < nSessionsPerDevice; j++) {
+                        store.storeEndToEndInboundGroupSession(
+                            pad43(`device${i}`),
+                            `session${j}`,
+                            {
+                                forwardingCurve25519KeyChain: [],
+                                keysClaimed: {},
+                                room_id: "",
+                                session: "",
+                            },
+                            txn,
+                        );
+                    }
+                }
+            });
+        }
+    });
+});
+
+/** Pad a string to 43 characters long */
+function pad43(x: string): string {
+    return x + ".".repeat(43 - x.length);
+}
@@ -0,0 +1,73 @@
+/*
+Copyright 2024 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import "fake-indexeddb/auto";
+import { IndexedDBCryptoStore } from "../../../../src";
+import { MigrationState } from "../../../../src/crypto/store/base";
+
+describe("IndexedDBCryptoStore", () => {
+    describe("Test `existsAndIsNotMigrated`", () => {
+        beforeEach(async () => {
+            // eslint-disable-next-line no-global-assign
+            indexedDB = new IDBFactory();
+        });
+
+        it("Should be true if there is a legacy database", async () => {
+            // should detect a store that is not migrated
+            const store = new IndexedDBCryptoStore(global.indexedDB, "tests");
+            await store.startup();
+
+            const result = await IndexedDBCryptoStore.existsAndIsNotMigrated(global.indexedDB, "tests");
+
+            expect(result).toBe(true);
+        });
+
+        it("Should be true if there is a legacy database in non migrated state", async () => {
+            // should detect a store that is not migrated
+            const store = new IndexedDBCryptoStore(global.indexedDB, "tests");
+            await store.startup();
+            await store.setMigrationState(MigrationState.NOT_STARTED);
+
+            const result = await IndexedDBCryptoStore.existsAndIsNotMigrated(global.indexedDB, "tests");
+
+            expect(result).toBe(true);
+        });
+
+        describe.each([
+            MigrationState.INITIAL_DATA_MIGRATED,
+            MigrationState.OLM_SESSIONS_MIGRATED,
+            MigrationState.MEGOLM_SESSIONS_MIGRATED,
+            MigrationState.ROOM_SETTINGS_MIGRATED,
+        ])("Exists and Migration state is %s", (migrationState) => {
+            it("Should be false if migration has started", async () => {
+                // should detect a store that is not migrated
+                const store = new IndexedDBCryptoStore(global.indexedDB, "tests");
+                await store.startup();
+                await store.setMigrationState(migrationState);
+
+                const result = await IndexedDBCryptoStore.existsAndIsNotMigrated(global.indexedDB, "tests");
+
+                expect(result).toBe(false);
+            });
+        });
+
+        it("Should be false if there is no legacy database", async () => {
+            const result = await IndexedDBCryptoStore.existsAndIsNotMigrated(global.indexedDB, "tests");
+
+            expect(result).toBe(false);
+        });
+    });
+});
@@ -55,6 +55,7 @@ import {
    RuleId,
    IPushRule,
    ConditionKind,
+    getHttpUriForMxc,
 } from "../../src";
 import { supportsMatrixCall } from "../../src/webrtc/call";
 import { makeBeaconEvent } from "../test-utils/beacon";
@@ -64,7 +65,7 @@ import {
    PolicyScope,
 } from "../../src/models/invites-ignorer";
 import { IOlmDevice } from "../../src/crypto/algorithms/megolm";
-import { QueryDict } from "../../src/utils";
+import { defer, QueryDict } from "../../src/utils";
 import { SyncState } from "../../src/sync";
 import * as featureUtils from "../../src/feature";
 import { StubStore } from "../../src/store/stub";
@@ -369,6 +370,21 @@ describe("MatrixClient", function () {
        client.stopClient();
    });

+    describe("mxcUrlToHttp", () => {
+        it("should call getHttpUriForMxc", () => {
+            const mxc = "mxc://server/example";
+            expect(client.mxcUrlToHttp(mxc)).toBe(getHttpUriForMxc(client.baseUrl, mxc));
+            expect(client.mxcUrlToHttp(mxc, 32)).toBe(getHttpUriForMxc(client.baseUrl, mxc, 32));
+            expect(client.mxcUrlToHttp(mxc, 32, 46)).toBe(getHttpUriForMxc(client.baseUrl, mxc, 32, 46));
+            expect(client.mxcUrlToHttp(mxc, 32, 46, "scale")).toBe(
+                getHttpUriForMxc(client.baseUrl, mxc, 32, 46, "scale"),
+            );
+            expect(client.mxcUrlToHttp(mxc, 32, 46, "scale", false, true)).toBe(
+                getHttpUriForMxc(client.baseUrl, mxc, 32, 46, "scale", false, true),
+            );
+        });
+    });
+
    describe("timestampToEvent", () => {
        const roomId = "!room:server.org";
        const eventId = "$eventId:example.org";
@@ -1434,25 +1450,11 @@ describe("MatrixClient", function () {
        const mockRoom = {
            getMyMembership: () => "join",
            updatePendingEvent: (event: MatrixEvent, status: EventStatus) => event.setStatus(status),
-            currentState: {
-                getStateEvents: (eventType, stateKey) => {
-                    if (eventType === EventType.RoomCreate) {
-                        expect(stateKey).toEqual("");
-                        return new MatrixEvent({
-                            content: {
-                                [RoomCreateTypeField]: RoomType.Space,
-                            },
-                        });
-                    } else if (eventType === EventType.RoomEncryption) {
-                        expect(stateKey).toEqual("");
-                        return new MatrixEvent({ content: {} });
-                    } else {
-                        throw new Error("Unexpected event type or state key");
-                    }
-                },
-            } as Room["currentState"],
+            hasEncryptionStateEvent: jest.fn().mockReturnValue(true),
        } as unknown as Room;

+        let mockCrypto: Mocked<Crypto>;
+
        let event: MatrixEvent;
        beforeEach(async () => {
            event = new MatrixEvent({
@@ -1467,11 +1469,12 @@ describe("MatrixClient", function () {
                expect(getRoomId).toEqual(roomId);
                return mockRoom;
            };
-            client.crypto = client["cryptoBackend"] = {
-                // mock crypto
-                encryptEvent: () => new Promise(() => {}),
+            mockCrypto = {
+                isEncryptionEnabledInRoom: jest.fn().mockResolvedValue(true),
+                encryptEvent: jest.fn(),
                stop: jest.fn(),
-            } as unknown as Crypto;
+            } as unknown as Mocked<Crypto>;
+            client.crypto = client["cryptoBackend"] = mockCrypto;
        });

        function assertCancelled() {
@@ -1488,12 +1491,21 @@ describe("MatrixClient", function () {
        });

        it("should cancel an event which is encrypting", async () => {
+            const encryptEventDefer = defer();
+            mockCrypto.encryptEvent.mockReturnValue(encryptEventDefer.promise);
+
+            const statusPromise = testUtils.emitPromise(event, "Event.status");
            // @ts-ignore protected method access
-            client.encryptAndSendEvent(mockRoom, event);
-            await testUtils.emitPromise(event, "Event.status");
+            const encryptAndSendPromise = client.encryptAndSendEvent(mockRoom, event);
+            await statusPromise;
            expect(event.status).toBe(EventStatus.ENCRYPTING);
            client.cancelPendingEvent(event);
            assertCancelled();
+
+            // now let the encryption complete, and check that the message is not sent.
+            encryptEventDefer.resolve();
+            await encryptAndSendPromise;
+            assertCancelled();
        });

        it("should cancel an event which is not sent", () => {
@@ -2211,8 +2223,7 @@ describe("MatrixClient", function () {
                    "org.matrix.msc3391": true,
                },
            };
-            jest.spyOn(client.http, "request").mockResolvedValue(versionsResponse);
-            const requestSpy = jest.spyOn(client.http, "authedRequest").mockImplementation(() => Promise.resolve());
+            const requestSpy = jest.spyOn(client.http, "authedRequest").mockResolvedValue(versionsResponse);
            const unstablePrefix = "/_matrix/client/unstable/org.matrix.msc3391";
            const path = `/user/${encodeURIComponent(userId)}/account_data/${eventType}`;

@@ -2250,8 +2261,7 @@ describe("MatrixClient", function () {
                    "org.matrix.msc3391": false,
                },
            };
-            jest.spyOn(client.http, "request").mockResolvedValue(versionsResponse);
-            const requestSpy = jest.spyOn(client.http, "authedRequest").mockImplementation(() => Promise.resolve());
+            const requestSpy = jest.spyOn(client.http, "authedRequest").mockResolvedValue(versionsResponse);
            const path = `/user/${encodeURIComponent(userId)}/account_data/${eventType}`;

            // populate version support
@@ -3002,4 +3012,22 @@ describe("MatrixClient", function () {
            expect(result).toEqual({});
        });
    });
+
+    describe("getAuthIssuer", () => {
+        it("should use unstable prefix", async () => {
+            httpLookups = [
+                {
+                    method: "GET",
+                    path: `/auth_issuer`,
+                    data: {
+                        issuer: "https://issuer/",
+                    },
+                    prefix: "/_matrix/client/unstable/org.matrix.msc2965",
+                },
+            ];
+
+            await expect(client.getAuthIssuer()).resolves.toEqual({ issuer: "https://issuer/" });
+            expect(httpLookups.length).toEqual(0);
+        });
+    });
 });
@@ -34,9 +34,12 @@ function makeMockEvent(originTs = 0): MatrixEvent {
 }

 describe("CallMembership", () => {
-    it("rejects membership with no expiry", () => {
+    it("rejects membership with no expiry and no expires_ts", () => {
        expect(() => {
-            new CallMembership(makeMockEvent(), Object.assign({}, membershipTemplate, { expires: undefined }));
+            new CallMembership(
+                makeMockEvent(),
+                Object.assign({}, membershipTemplate, { expires: undefined, expires_ts: undefined }),
+            );
        }).toThrow();
    });

@@ -57,6 +60,16 @@ describe("CallMembership", () => {
            new CallMembership(makeMockEvent(), Object.assign({}, membershipTemplate, { scope: undefined }));
        }).toThrow();
    });
+    it("rejects with malformatted expires_ts", () => {
+        expect(() => {
+            new CallMembership(makeMockEvent(), Object.assign({}, membershipTemplate, { expires_ts: "string" }));
+        }).toThrow();
+    });
+    it("rejects with malformatted expires", () => {
+        expect(() => {
+            new CallMembership(makeMockEvent(), Object.assign({}, membershipTemplate, { expires: "string" }));
+        }).toThrow();
+    });

    it("uses event timestamp if no created_ts", () => {
        const membership = new CallMembership(makeMockEvent(12345), membershipTemplate);
@@ -71,11 +84,19 @@ describe("CallMembership", () => {
        expect(membership.createdTs()).toEqual(67890);
    });

-    it("computes absolute expiry time", () => {
+    it("computes absolute expiry time based on expires", () => {
        const membership = new CallMembership(makeMockEvent(1000), membershipTemplate);
        expect(membership.getAbsoluteExpiry()).toEqual(5000 + 1000);
    });

+    it("computes absolute expiry time based on expires_ts", () => {
+        const membership = new CallMembership(
+            makeMockEvent(1000),
+            Object.assign({}, membershipTemplate, { expires: undefined, expires_ts: 6000 }),
+        );
+        expect(membership.getAbsoluteExpiry()).toEqual(5000 + 1000);
+    });
+
    it("considers memberships unexpired if local age low enough", () => {
        const fakeEvent = makeMockEvent(1000);
        fakeEvent.getLocalAge = jest.fn().mockReturnValue(3000);
@@ -74,6 +74,13 @@ describe("MatrixRTCSession", () => {
        expect(sess?.memberships[0].deviceId).toEqual("AAAAAAA");
    });

+    it("ignores memberships events of members not in the room", () => {
+        const mockRoom = makeMockRoom([membershipTemplate]);
+        mockRoom.hasMembershipState = (state) => state === "join";
+        sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
+        expect(sess?.memberships.length).toEqual(0);
+    });
+
    it("honours created_ts", () => {
        const expiredMembership = Object.assign({}, membershipTemplate);
        expiredMembership.created_ts = 500;
@@ -91,9 +98,12 @@ describe("MatrixRTCSession", () => {

    it("safely ignores events with no memberships section", () => {
        const mockRoom = {
+            ...makeMockRoom([]),
            roomId: randomString(8),
            getLiveTimeline: jest.fn().mockReturnValue({
                getState: jest.fn().mockReturnValue({
+                    on: jest.fn(),
+                    off: jest.fn(),
                    getStateEvents: (_type: string, _stateKey: string) => [
                        {
                            getType: jest.fn().mockReturnValue(EventType.GroupCallMemberPrefix),
@@ -112,9 +122,12 @@ describe("MatrixRTCSession", () => {

    it("safely ignores events with junk memberships section", () => {
        const mockRoom = {
+            ...makeMockRoom([]),
            roomId: randomString(8),
            getLiveTimeline: jest.fn().mockReturnValue({
                getState: jest.fn().mockReturnValue({
+                    on: jest.fn(),
+                    off: jest.fn(),
                    getStateEvents: (_type: string, _stateKey: string) => [
                        {
                            getType: jest.fn().mockReturnValue(EventType.GroupCallMemberPrefix),
@@ -214,8 +227,8 @@ describe("MatrixRTCSession", () => {
        });

        it("sends a membership event when joining a call", () => {
+            jest.useFakeTimers();
            sess!.joinRoomSession([mockFocus]);
-
            expect(client.sendStateEvent).toHaveBeenCalledWith(
                mockRoom!.roomId,
                EventType.GroupCallMemberPrefix,
@@ -227,6 +240,7 @@ describe("MatrixRTCSession", () => {
                            call_id: "",
                            device_id: "AAAAAAA",
                            expires: 3600000,
+                            expires_ts: Date.now() + 3600000,
                            foci_active: [{ type: "mock" }],
                            membershipID: expect.stringMatching(".*"),
                        },
@@ -234,6 +248,7 @@ describe("MatrixRTCSession", () => {
                },
                "@alice:example.org",
            );
+            jest.useRealTimers();
        });

        it("does nothing if join called when already joined", () => {
@@ -291,6 +306,7 @@ describe("MatrixRTCSession", () => {
                                call_id: "",
                                device_id: "AAAAAAA",
                                expires: 3600000 * 2,
+                                expires_ts: 1000 + 3600000 * 2,
                                foci_active: [{ type: "mock" }],
                                created_ts: 1000,
                                membershipID: expect.stringMatching(".*"),
@@ -510,7 +526,7 @@ describe("MatrixRTCSession", () => {
        });
    });

-    it("Does not emits if no membership changes", () => {
+    it("Does not emit if no membership changes", () => {
        const mockRoom = makeMockRoom([membershipTemplate]);
        sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);

@@ -591,6 +607,7 @@ describe("MatrixRTCSession", () => {
                            call_id: "",
                            device_id: "AAAAAAA",
                            expires: 3600000,
+                            expires_ts: Date.now() + 3600000,
                            foci_active: [mockFocus],
                            membershipID: expect.stringMatching(".*"),
                        },
@@ -605,7 +622,7 @@ describe("MatrixRTCSession", () => {

    it("fills in created_ts for other memberships on update", () => {
        client.sendStateEvent = jest.fn();
-
+        jest.useFakeTimers();
        const mockRoom = makeMockRoom([
            Object.assign({}, membershipTemplate, {
                device_id: "OTHERDEVICE",
@@ -635,6 +652,7 @@ describe("MatrixRTCSession", () => {
                        call_id: "",
                        device_id: "AAAAAAA",
                        expires: 3600000,
+                        expires_ts: Date.now() + 3600000,
                        foci_active: [mockFocus],
                        membershipID: expect.stringMatching(".*"),
                    },
@@ -642,6 +660,7 @@ describe("MatrixRTCSession", () => {
            },
            "@alice:example.org",
        );
+        jest.useRealTimers();
    });

    it("collects keys from encryption events", () => {
@@ -87,7 +87,7 @@ describe("MatrixRTCSessionManager", () => {
        expect(onEnded).toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
    });

-    it("Calls onCallEncryption on encryption keys event", () => {
+    it("Calls onCallEncryption on encryption keys event", async () => {
        const room1 = makeMockRoom([membershipTemplate]);
        jest.spyOn(client, "getRooms").mockReturnValue([room1]);
        jest.spyOn(client, "getRoom").mockReturnValue(room1);
@@ -95,7 +95,7 @@ describe("MatrixRTCSessionManager", () => {
        client.emit(ClientEvent.Room, room1);
        const onCallEncryptionMock = jest.fn();
        client.matrixRTC.getRoomSession(room1).onCallEncryption = onCallEncryptionMock;
-
+        client.decryptEventIfNeeded = () => Promise.resolve();
        const timelineEvent = {
            getType: jest.fn().mockReturnValue(EventType.CallEncryptionKeysPrefix),
            getContent: jest.fn().mockReturnValue({}),
@@ -106,6 +106,7 @@ describe("MatrixRTCSessionManager", () => {
            },
        } as unknown as MatrixEvent;
        client.emit(RoomEvent.Timeline, timelineEvent, undefined, undefined, false, {} as IRoomTimelineData);
+        await new Promise(process.nextTick);
        expect(onCallEncryptionMock).toHaveBeenCalled();
    });
 });
@@ -24,6 +24,7 @@ export function makeMockRoom(memberships: CallMembershipData[], localAge: number
    const roomState = makeMockRoomState(memberships, roomId, localAge);
    return {
        roomId: roomId,
+        hasMembershipState: jest.fn().mockReturnValue(true),
        getLiveTimeline: jest.fn().mockReturnValue({
            getState: jest.fn().mockReturnValue(roomState),
        }),
@@ -33,6 +34,8 @@ export function makeMockRoom(memberships: CallMembershipData[], localAge: number
 export function makeMockRoomState(memberships: CallMembershipData[], roomId: string, localAge: number | null = null) {
    const event = mockRTCEvent(memberships, roomId, localAge);
    return {
+        on: jest.fn(),
+        off: jest.fn(),
        getStateEvents: (_: string, stateKey: string) => {
            if (stateKey !== undefined) return event;
            return [event];
@@ -213,7 +213,7 @@ describe("MSC3089Branch", () => {
                    expect(eventId).toEqual(fileEventId);
                    return fileEvent;
                },
-            } as EventTimelineSet);
+            }) as EventTimelineSet;
        client.mxcUrlToHttp = (mxc: string) => {
            expect(mxc).toEqual("mxc://" + mxcLatter);
            return `https://example.org/_matrix/media/v1/download/${mxcLatter}`;
@@ -239,7 +239,7 @@ describe("MSC3089Branch", () => {
                    expect(eventId).toEqual(fileEventId);
                    return fileEvent;
                },
-            } as EventTimelineSet);
+            }) as EventTimelineSet;
        client.mxcUrlToHttp = (mxc: string) => {
            expect(mxc).toEqual("mxc://" + mxcLatter);
            return `https://example.org/_matrix/media/v1/download/${mxcLatter}`;
@@ -332,7 +332,7 @@ describe("MSC3089Branch", () => {
                getId: () => "$unknown",
            },
        ];
-        staticRoom.getLiveTimeline = () => ({ getEvents: () => events } as EventTimeline);
+        staticRoom.getLiveTimeline = () => ({ getEvents: () => events }) as EventTimeline;

        directory.getFile = (evId: string) => {
            expect(evId).toEqual(fileEventId);
@@ -399,7 +399,7 @@ describe("MSC3089TreeSpace", () => {
                ];
            },
        };
-        client.getRoom = () => ({} as Room); // to appease the TreeSpace constructor
+        client.getRoom = () => ({}) as Room; // to appease the TreeSpace constructor

        const getFn = jest.fn().mockImplementation((roomId: string) => {
            if (roomId === thirdChildRoom) {
@@ -422,7 +422,7 @@ describe("MSC3089TreeSpace", () => {
    });

    it("should find specific directories", () => {
-        client.getRoom = () => ({} as Room); // to appease the TreeSpace constructor
+        client.getRoom = () => ({}) as Room; // to appease the TreeSpace constructor

        // Only mocking used API
        const firstSubdirectory = { roomId: "!first:example.org" } as any as MSC3089TreeSpace;
@@ -20,7 +20,10 @@ limitations under the License.

 import fetchMock from "fetch-mock-jest";
 import { mocked } from "jest-mock";
-import jwtDecode from "jwt-decode";
+import { jwtDecode } from "jwt-decode";
+import { Crypto } from "@peculiar/webcrypto";
+import { getRandomValues } from "node:crypto";
+import { TextEncoder } from "node:util";

 import { Method } from "../../../src";
 import * as crypto from "../../../src/crypto/crypto";
@@ -36,13 +39,15 @@ import { makeDelegatedAuthConfig, mockOpenIdConfiguration } from "../../test-uti

 jest.mock("jwt-decode");

+const webCrypto = new Crypto();
+
 // save for resetting mocks
 const realSubtleCrypto = crypto.subtleCrypto;

 describe("oidc authorization", () => {
    const delegatedAuthConfig = makeDelegatedAuthConfig();
-    const authorizationEndpoint = delegatedAuthConfig.metadata.authorization_endpoint;
-    const tokenEndpoint = delegatedAuthConfig.metadata.token_endpoint;
+    const authorizationEndpoint = delegatedAuthConfig.authorizationEndpoint;
+    const tokenEndpoint = delegatedAuthConfig.tokenEndpoint;
    const clientId = "xyz789";
    const baseUrl = "https://test.com";

@@ -53,7 +58,19 @@ describe("oidc authorization", () => {
        jest.spyOn(logger, "warn");
        jest.setSystemTime(now);

-        fetchMock.get(delegatedAuthConfig.issuer + ".well-known/openid-configuration", mockOpenIdConfiguration());
+        fetchMock.get(
+            delegatedAuthConfig.metadata.issuer + ".well-known/openid-configuration",
+            mockOpenIdConfiguration(),
+        );
+
+        Object.defineProperty(window, "crypto", {
+            value: {
+                getRandomValues,
+                randomUUID: jest.fn().mockReturnValue("not-random-uuid"),
+                subtle: webCrypto.subtle,
+            },
+        });
+        global.TextEncoder = TextEncoder;
    });

    afterEach(() => {
@@ -165,7 +182,8 @@ describe("oidc authorization", () => {
            token_type: "Bearer",
            access_token: "test_access_token",
            refresh_token: "test_refresh_token",
-            id_token: "valid.id.token",
+            id_token:
+                "eyJhbGciOiJSUzI1NiIsImtpZCI6Imh4ZEhXb0Y5bW4ifQ.eyJleHAiOjE3MDgzNTY3NjcsInN1YiI6IjAxSFBQMkZTQllERTlQOUVNTThERDdXWkhSIiwiYXVkIjoiMDFIUTBXSDUyV0paV1JSU1k5V0VFUTVUMlEiLCJub25jZSI6ImhScEI2cGtFMDYiLCJhdXRoX3RpbWUiOjE3MDc5OTAzMTIsImlhdCI6MTcwODM1MzE2NywiYXRfaGFzaCI6Il9HSEU4cDhocHFnMW1ac041YUlycVEiLCJpc3MiOiJodHRwczovL2F1dGgtb2lkYy5sYWIuZWxlbWVudC5kZXYvIiwiY19oYXNoIjoib2hJRmNuaUZWd3pGSzVJdXlsX1RlQSJ9.SGUG78dCC3sTWgQBDTicKwamKiPpb6REiz79CM2ml_kVJCoS7gT0TlztC4h25FKi3c9aB3XCVn9J8UzvJgvG8Rt_oS--FIuhK6oRm7NdcN0bCkbG7iZEWGxx-kQnifcCFHyZ6T1CxR8X00Uvc6_lRfBZVlTyuuQaJ_PHiiKMlV93FbxvQUIq6FTkQP2Z56p4JIXIzjOONzA91skTqQGycl5f9Vhp6cqXFzl6ARK30M7A-8UI5qCxClUJ7kD9KgN5YZ7uivLp1x01WBnik2DXH0eSwXcTX2WLkYtMXgMxylJhIiO586apIC5nr7sfip-Y_4PgBlSjRRgrmOGC-VUFCA",
            expires_in: 300,
        };

@@ -17,39 +17,48 @@ limitations under the License.
 import fetchMockJest from "fetch-mock-jest";

 import { OidcError } from "../../../src/oidc/error";
-import { registerOidcClient } from "../../../src/oidc/register";
+import { OidcRegistrationClientMetadata, registerOidcClient } from "../../../src/oidc/register";
+import { makeDelegatedAuthConfig } from "../../test-utils/oidc";

 describe("registerOidcClient()", () => {
    const issuer = "https://auth.com/";
-    const registrationEndpoint = "https://auth.com/register";
    const clientName = "Element";
    const baseUrl = "https://just.testing";
+    const metadata: OidcRegistrationClientMetadata = {
+        clientUri: baseUrl,
+        redirectUris: [baseUrl],
+        clientName,
+        applicationType: "web",
+        tosUri: "http://tos-uri",
+        policyUri: "http://policy-uri",
+        contacts: ["admin@example.com"],
+    };
    const dynamicClientId = "xyz789";

-    const delegatedAuthConfig = {
-        issuer,
-        registrationEndpoint,
-        authorizationEndpoint: issuer + "auth",
-        tokenEndpoint: issuer + "token",
-    };
+    const delegatedAuthConfig = makeDelegatedAuthConfig(issuer);
    beforeEach(() => {
        fetchMockJest.mockClear();
        fetchMockJest.resetBehavior();
    });

    it("should make correct request to register client", async () => {
-        fetchMockJest.post(registrationEndpoint, {
+        fetchMockJest.post(delegatedAuthConfig.registrationEndpoint!, {
            status: 200,
            body: JSON.stringify({ client_id: dynamicClientId }),
        });
-        expect(await registerOidcClient(delegatedAuthConfig, clientName, baseUrl)).toEqual(dynamicClientId);
-        expect(fetchMockJest).toHaveBeenCalledWith(registrationEndpoint, {
-            headers: {
-                "Accept": "application/json",
-                "Content-Type": "application/json",
-            },
-            method: "POST",
-            body: JSON.stringify({
+        expect(await registerOidcClient(delegatedAuthConfig, metadata)).toEqual(dynamicClientId);
+        expect(fetchMockJest).toHaveBeenCalledWith(
+            delegatedAuthConfig.registrationEndpoint!,
+            expect.objectContaining({
+                headers: {
+                    "Accept": "application/json",
+                    "Content-Type": "application/json",
+                },
+                method: "POST",
+            }),
+        );
+        expect(JSON.parse(fetchMockJest.mock.calls[0][1]!.body as string)).toEqual(
+            expect.objectContaining({
                client_name: clientName,
                client_uri: baseUrl,
                response_types: ["code"],
@@ -59,25 +68,25 @@ describe("registerOidcClient()", () => {
                token_endpoint_auth_method: "none",
                application_type: "web",
            }),
-        });
+        );
    });

    it("should throw when registration request fails", async () => {
-        fetchMockJest.post(registrationEndpoint, {
+        fetchMockJest.post(delegatedAuthConfig.registrationEndpoint!, {
            status: 500,
        });
-        await expect(() => registerOidcClient(delegatedAuthConfig, clientName, baseUrl)).rejects.toThrow(
+        await expect(() => registerOidcClient(delegatedAuthConfig, metadata)).rejects.toThrow(
            OidcError.DynamicRegistrationFailed,
        );
    });

    it("should throw when registration response is invalid", async () => {
-        fetchMockJest.post(registrationEndpoint, {
+        fetchMockJest.post(delegatedAuthConfig.registrationEndpoint!, {
            status: 200,
            // no clientId in response
            body: "{}",
        });
-        await expect(() => registerOidcClient(delegatedAuthConfig, clientName, baseUrl)).rejects.toThrow(
+        await expect(() => registerOidcClient(delegatedAuthConfig, metadata)).rejects.toThrow(
            OidcError.DynamicRegistrationInvalid,
        );
    });
@@ -64,7 +64,7 @@ describe("OidcTokenRefresher", () => {
            keys: [],
        });

-        fetchMock.post(config.metadata.token_endpoint, {
+        fetchMock.post(config.tokenEndpoint, {
            status: 200,
            headers: {
                "Content-Type": "application/json",
@@ -88,7 +88,7 @@ describe("OidcTokenRefresher", () => {
            },
            { overwriteRoutes: true },
        );
-        const refresher = new OidcTokenRefresher(authConfig, clientId, redirectUri, deviceId, idTokenClaims);
+        const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
        await expect(refresher.oidcClientReady).rejects.toThrow();
        expect(logger.error).toHaveBeenCalledWith(
            "Failed to initialise OIDC client.",
@@ -98,7 +98,7 @@ describe("OidcTokenRefresher", () => {
    });

    it("initialises oidc client", async () => {
-        const refresher = new OidcTokenRefresher(authConfig, clientId, redirectUri, deviceId, idTokenClaims);
+        const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
        await refresher.oidcClientReady;

        // @ts-ignore peek at private property to see we initialised the client correctly
@@ -114,19 +114,19 @@ describe("OidcTokenRefresher", () => {

    describe("doRefreshAccessToken()", () => {
        it("should throw when oidcClient has not been initialised", async () => {
-            const refresher = new OidcTokenRefresher(authConfig, clientId, redirectUri, deviceId, idTokenClaims);
+            const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
            await expect(refresher.doRefreshAccessToken("token")).rejects.toThrow(
                "Cannot get new token before OIDC client is initialised.",
            );
        });

        it("should refresh the tokens", async () => {
-            const refresher = new OidcTokenRefresher(authConfig, clientId, redirectUri, deviceId, idTokenClaims);
+            const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
            await refresher.oidcClientReady;

            const result = await refresher.doRefreshAccessToken("refresh-token");

-            expect(fetchMock).toHaveFetched(config.metadata.token_endpoint, {
+            expect(fetchMock).toHaveFetched(config.tokenEndpoint, {
                method: "POST",
            });

@@ -137,7 +137,7 @@ describe("OidcTokenRefresher", () => {
        });

        it("should persist the new tokens", async () => {
-            const refresher = new OidcTokenRefresher(authConfig, clientId, redirectUri, deviceId, idTokenClaims);
+            const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
            await refresher.oidcClientReady;
            // spy on our stub
            jest.spyOn(refresher, "persistTokens");
@@ -153,7 +153,7 @@ describe("OidcTokenRefresher", () => {
        it("should only have one inflight refresh request at once", async () => {
            fetchMock
                .postOnce(
-                    config.metadata.token_endpoint,
+                    config.tokenEndpoint,
                    {
                        status: 200,
                        headers: {
@@ -164,7 +164,7 @@ describe("OidcTokenRefresher", () => {
                    { overwriteRoutes: true },
                )
                .postOnce(
-                    config.metadata.token_endpoint,
+                    config.tokenEndpoint,
                    {
                        status: 200,
                        headers: {
@@ -175,7 +175,7 @@ describe("OidcTokenRefresher", () => {
                    { overwriteRoutes: false },
                );

-            const refresher = new OidcTokenRefresher(authConfig, clientId, redirectUri, deviceId, idTokenClaims);
+            const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
            await refresher.oidcClientReady;
            // reset call counts
            fetchMock.resetHistory();
@@ -188,7 +188,7 @@ describe("OidcTokenRefresher", () => {
            const result2 = await first;

            // only one call to token endpoint
-            expect(fetchMock).toHaveFetchedTimes(1, config.metadata.token_endpoint);
+            expect(fetchMock).toHaveFetchedTimes(1, config.tokenEndpoint);
            expect(result1).toEqual({
                accessToken: "first-new-access-token",
                refreshToken: "first-new-refresh-token",
@@ -208,7 +208,7 @@ describe("OidcTokenRefresher", () => {

        it("should log and rethrow when token refresh fails", async () => {
            fetchMock.post(
-                config.metadata.token_endpoint,
+                config.tokenEndpoint,
                {
                    status: 503,
                    headers: {
@@ -218,7 +218,7 @@ describe("OidcTokenRefresher", () => {
                { overwriteRoutes: true },
            );

-            const refresher = new OidcTokenRefresher(authConfig, clientId, redirectUri, deviceId, idTokenClaims);
+            const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
            await refresher.oidcClientReady;

            await expect(refresher.doRefreshAccessToken("refresh-token")).rejects.toThrow();
@@ -228,7 +228,7 @@ describe("OidcTokenRefresher", () => {
            // make sure inflight request is cleared after a failure
            fetchMock
                .postOnce(
-                    config.metadata.token_endpoint,
+                    config.tokenEndpoint,
                    {
                        status: 503,
                        headers: {
@@ -238,7 +238,7 @@ describe("OidcTokenRefresher", () => {
                    { overwriteRoutes: true },
                )
                .postOnce(
-                    config.metadata.token_endpoint,
+                    config.tokenEndpoint,
                    {
                        status: 200,
                        headers: {
@@ -249,7 +249,7 @@ describe("OidcTokenRefresher", () => {
                    { overwriteRoutes: false },
                );

-            const refresher = new OidcTokenRefresher(authConfig, clientId, redirectUri, deviceId, idTokenClaims);
+            const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
            await refresher.oidcClientReady;
            // reset call counts
            fetchMock.resetHistory();
@@ -15,107 +15,14 @@ limitations under the License.
 */

 import { mocked } from "jest-mock";
-import jwtDecode from "jwt-decode";
+import { jwtDecode } from "jwt-decode";

-import { M_AUTHENTICATION } from "../../../src";
 import { logger } from "../../../src/logger";
-import {
-    validateIdToken,
-    validateOIDCIssuerWellKnown,
-    validateWellKnownAuthentication,
-} from "../../../src/oidc/validate";
+import { validateIdToken, validateOIDCIssuerWellKnown } from "../../../src/oidc/validate";
 import { OidcError } from "../../../src/oidc/error";

 jest.mock("jwt-decode");

-describe("validateWellKnownAuthentication()", () => {
-    const baseWk = {
-        "m.homeserver": {
-            base_url: "https://hs.org",
-        },
-    };
-    it("should throw not supported error when wellKnown has no m.authentication section", () => {
-        expect(() => validateWellKnownAuthentication(undefined)).toThrow(OidcError.NotSupported);
-    });
-
-    it("should throw misconfigured error when authentication issuer is not a string", () => {
-        const wk = {
-            ...baseWk,
-            [M_AUTHENTICATION.stable!]: {
-                issuer: { url: "test.com" },
-            },
-        };
-        expect(() => validateWellKnownAuthentication(wk[M_AUTHENTICATION.stable!] as any)).toThrow(
-            OidcError.Misconfigured,
-        );
-    });
-
-    it("should throw misconfigured error when authentication account is not a string", () => {
-        const wk = {
-            ...baseWk,
-            [M_AUTHENTICATION.stable!]: {
-                issuer: "test.com",
-                account: { url: "test" },
-            },
-        };
-        expect(() => validateWellKnownAuthentication(wk[M_AUTHENTICATION.stable!] as any)).toThrow(
-            OidcError.Misconfigured,
-        );
-    });
-
-    it("should throw misconfigured error when authentication account is false", () => {
-        const wk = {
-            ...baseWk,
-            [M_AUTHENTICATION.stable!]: {
-                issuer: "test.com",
-                account: false,
-            },
-        };
-        expect(() => validateWellKnownAuthentication(wk[M_AUTHENTICATION.stable!] as any)).toThrow(
-            OidcError.Misconfigured,
-        );
-    });
-
-    it("should return valid config when wk uses stable m.authentication", () => {
-        const wk = {
-            ...baseWk,
-            [M_AUTHENTICATION.stable!]: {
-                issuer: "test.com",
-                account: "account.com",
-            },
-        };
-        expect(validateWellKnownAuthentication(wk[M_AUTHENTICATION.stable!])).toEqual({
-            issuer: "test.com",
-            account: "account.com",
-        });
-    });
-
-    it("should return valid config when m.authentication account is missing", () => {
-        const wk = {
-            ...baseWk,
-            [M_AUTHENTICATION.stable!]: {
-                issuer: "test.com",
-            },
-        };
-        expect(validateWellKnownAuthentication(wk[M_AUTHENTICATION.stable!])).toEqual({
-            issuer: "test.com",
-        });
-    });
-
-    it("should remove unexpected properties", () => {
-        const wk = {
-            ...baseWk,
-            [M_AUTHENTICATION.stable!]: {
-                issuer: "test.com",
-                somethingElse: "test",
-            },
-        };
-        expect(validateWellKnownAuthentication(wk[M_AUTHENTICATION.stable!])).toEqual({
-            issuer: "test.com",
-        });
-    });
-});
-
 describe("validateOIDCIssuerWellKnown", () => {
    const validWk: any = {
        authorization_endpoint: "https://test.org/authorize",
@@ -125,6 +32,8 @@ describe("validateOIDCIssuerWellKnown", () => {
        response_types_supported: ["code"],
        grant_types_supported: ["authorization_code"],
        code_challenge_methods_supported: ["S256"],
+        account_management_uri: "https://authorize.org/account",
+        account_management_actions_supported: ["org.matrix.cross_signing_reset"],
    };
    beforeEach(() => {
        // stub to avoid console litter
@@ -157,6 +66,8 @@ describe("validateOIDCIssuerWellKnown", () => {
            authorizationEndpoint: validWk.authorization_endpoint,
            tokenEndpoint: validWk.token_endpoint,
            registrationEndpoint: validWk.registration_endpoint,
+            accountManagementActionsSupported: ["org.matrix.cross_signing_reset"],
+            accountManagementEndpoint: "https://authorize.org/account",
        });
    });

@@ -167,6 +78,8 @@ describe("validateOIDCIssuerWellKnown", () => {
            authorizationEndpoint: validWk.authorization_endpoint,
            tokenEndpoint: validWk.token_endpoint,
            registrationEndpoint: undefined,
+            accountManagementActionsSupported: ["org.matrix.cross_signing_reset"],
+            accountManagementEndpoint: "https://authorize.org/account",
        });
    });

@@ -186,6 +99,8 @@ describe("validateOIDCIssuerWellKnown", () => {
        ["code_challenge_methods_supported", undefined],
        ["code_challenge_methods_supported", "not an array"],
        ["code_challenge_methods_supported", ["doesnt include S256"]],
+        ["account_management_uri", { not: "a string" }],
+        ["account_management_actions_supported", { not: "an array" }],
    ])("should throw OP support error when %s is %s", (key, value) => {
        const wk = {
            ...validWk,
@@ -265,6 +265,7 @@ describe.each([[StoreType.Memory], [StoreType.IndexedDB]])("queueToDevice (%s st
        });
        const mockRoom = {
            updatePendingEvent: jest.fn(),
+            hasEncryptionStateEvent: jest.fn().mockReturnValue(false),
        } as unknown as Room;
        client.resendEvent(dummyEvent, mockRoom);

@@ -32,7 +32,10 @@ export class DummyTransport<D extends RendezvousTransportDetails, T> implements
    ready = false;
    cancelled = false;

-    constructor(private name: string, private mockDetails: D) {}
+    constructor(
+        private name: string,
+        private mockDetails: D,
+    ) {}
    onCancelled?: RendezvousFailureListener;

    details(): Promise<RendezvousTransportDetails> {
@@ -23,7 +23,7 @@ import {
    MSC3903ECDHPayload,
    MSC3903ECDHv2RendezvousChannel as MSC3903ECDHRendezvousChannel,
 } from "../../../src/rendezvous/channels";
-import { MatrixClient } from "../../../src";
+import { Device, MatrixClient } from "../../../src";
 import {
    MSC3886SimpleHttpRendezvousTransport,
    MSC3886SimpleHttpRendezvousTransportDetails,
@@ -31,16 +31,57 @@ import {
 import { DummyTransport } from "./DummyTransport";
 import { decodeBase64 } from "../../../src/base64";
 import { logger } from "../../../src/logger";
-import { DeviceInfo } from "../../../src/crypto/deviceinfo";
+import { CrossSigningKey, OwnDeviceKeys } from "../../../src/crypto-api";
+
+type UserID = string;
+type DeviceID = string;
+type Fingerprint = string;
+type SimpleDeviceMap = Record<UserID, Record<DeviceID, Fingerprint>>;
+
+function mockDevice(userId: UserID, deviceId: DeviceID, fingerprint: Fingerprint): Device {
+    return {
+        deviceId,
+        userId,
+        getFingerprint: () => fingerprint,
+    } as unknown as Device;
+}
+
+function mockDeviceMap(
+    userId: UserID,
+    deviceId: DeviceID,
+    deviceKey?: Fingerprint,
+    otherDevices: SimpleDeviceMap = {},
+): Map<string, Map<string, Device>> {
+    const deviceMap: Map<string, Map<string, Device>> = new Map();
+
+    const myDevices: Map<string, Device> = new Map();
+    if (deviceKey) {
+        myDevices.set(deviceId, mockDevice(userId, deviceId, deviceKey));
+    }
+    deviceMap.set(userId, myDevices);
+
+    for (const u in otherDevices) {
+        let userDevices = deviceMap.get(u);
+        if (!userDevices) {
+            userDevices = new Map();
+            deviceMap.set(u, userDevices);
+        }
+        for (const d in otherDevices[u]) {
+            userDevices.set(d, mockDevice(u, d, otherDevices[u][d]));
+        }
+    }
+
+    return deviceMap;
+}

 function makeMockClient(opts: {
-    userId: string;
-    deviceId: string;
-    deviceKey?: string;
+    userId: UserID;
+    deviceId: DeviceID;
+    deviceKey?: Fingerprint;
    getLoginTokenEnabled: boolean;
    msc3882r0Only: boolean;
    msc3886Enabled: boolean;
-    devices?: Record<string, Partial<DeviceInfo>>;
+    devices?: SimpleDeviceMap;
    verificationFunction?: (
        userId: string,
        deviceId: string,
@@ -48,50 +89,77 @@ function makeMockClient(opts: {
        blocked: boolean,
        known: boolean,
    ) => void;
-    crossSigningIds?: Record<string, string>;
-}): MatrixClient {
-    return {
-        getVersions() {
-            return {
-                unstable_features: {
-                    "org.matrix.msc3882": opts.getLoginTokenEnabled,
-                    "org.matrix.msc3886": opts.msc3886Enabled,
-                },
-            };
-        },
-        getCapabilities() {
-            return opts.msc3882r0Only
-                ? {}
-                : {
-                      capabilities: {
-                          "m.get_login_token": {
-                              enabled: opts.getLoginTokenEnabled,
+    crossSigningIds?: Partial<Record<CrossSigningKey, string>>;
+}): [MatrixClient, Map<string, Map<string, Device>>] {
+    const deviceMap = mockDeviceMap(opts.userId, opts.deviceId, opts.deviceKey, opts.devices);
+    return [
+        {
+            doesServerSupportUnstableFeature: jest.fn().mockImplementation((feature) => {
+                if (feature === "org.matrix.msc3886") {
+                    return opts.msc3886Enabled;
+                } else if (feature === "org.matrix.msc3882") {
+                    return opts.getLoginTokenEnabled;
+                } else {
+                    return false;
+                }
+            }),
+            getVersions() {
+                return {
+                    unstable_features: {
+                        "org.matrix.msc3882": opts.getLoginTokenEnabled,
+                        "org.matrix.msc3886": opts.msc3886Enabled,
+                    },
+                };
+            },
+            getCapabilities() {
+                return opts.msc3882r0Only
+                    ? {}
+                    : {
+                          capabilities: {
+                              "m.get_login_token": {
+                                  enabled: opts.getLoginTokenEnabled,
+                              },
                          },
-                      },
-                  };
-        },
-        getUserId() {
-            return opts.userId;
-        },
-        getDeviceId() {
-            return opts.deviceId;
-        },
-        getDeviceEd25519Key() {
-            return opts.deviceKey;
-        },
-        baseUrl: "https://example.com",
-        crypto: {
-            getStoredDevice(userId: string, deviceId: string) {
-                return opts.devices?.[deviceId] ?? null;
+                      };
            },
-            setDeviceVerification: opts.verificationFunction,
-            crossSigningInfo: {
-                getId(key: string) {
-                    return opts.crossSigningIds?.[key];
-                },
+            getUserId() {
+                return opts.userId;
            },
-        },
-    } as unknown as MatrixClient;
+            getSafeUserId() {
+                return opts.userId;
+            },
+            getDeviceId() {
+                return opts.deviceId;
+            },
+            baseUrl: "https://example.com",
+            getCrypto() {
+                return {
+                    getUserDeviceInfo(
+                        [userId]: string[],
+                        downloadUncached?: boolean,
+                    ): Promise<Map<string, Map<string, Device>>> {
+                        return Promise.resolve(deviceMap);
+                    },
+                    getCrossSigningKeyId(key: CrossSigningKey): string | null {
+                        return opts.crossSigningIds?.[key] ?? null;
+                    },
+                    setDeviceVerified(userId: string, deviceId: string, verified: boolean): Promise<void> {
+                        return Promise.resolve();
+                    },
+                    crossSignDevice(deviceId: string): Promise<void> {
+                        return Promise.resolve();
+                    },
+                    getOwnDeviceKeys(): Promise<OwnDeviceKeys> {
+                        return Promise.resolve({
+                            ed25519: opts.deviceKey!,
+                            curve25519: "aaaa",
+                        });
+                    },
+                };
+            },
+        } as unknown as MatrixClient,
+        deviceMap,
+    ];
 }

 function makeTransport(name: string, uri = "https://test.rz/123456") {
@@ -106,6 +174,7 @@ describe("Rendezvous", function () {
    let httpBackend: MockHttpBackend;
    let fetchFn: typeof global.fetch;
    let transports: DummyTransport<any, MSC3903ECDHPayload>[];
+    const userId: UserID = "@user:example.com";

    beforeEach(function () {
        httpBackend = new MockHttpBackend();
@@ -118,9 +187,9 @@ describe("Rendezvous", function () {
    });

    it("generate and cancel", async function () {
-        const alice = makeMockClient({
-            userId: "@alice:example.com",
-            deviceId: "DEVICEID",
+        const [alice] = makeMockClient({
+            userId,
+            deviceId: "ALICE",
            msc3886Enabled: false,
            getLoginTokenEnabled: true,
            msc3882r0Only: true,
@@ -194,8 +263,8 @@ describe("Rendezvous", function () {

        // alice is already signs in and generates a code
        const aliceOnFailure = jest.fn();
-        const alice = makeMockClient({
-            userId: "alice",
+        const [alice] = makeMockClient({
+            userId,
            deviceId: "ALICE",
            msc3886Enabled: false,
            getLoginTokenEnabled,
@@ -257,8 +326,8 @@ describe("Rendezvous", function () {

        // alice is already signs in and generates a code
        const aliceOnFailure = jest.fn();
-        const alice = makeMockClient({
-            userId: "alice",
+        const [alice] = makeMockClient({
+            userId,
            deviceId: "ALICE",
            getLoginTokenEnabled: true,
            msc3882r0Only: false,
@@ -316,8 +385,8 @@ describe("Rendezvous", function () {

        // alice is already signs in and generates a code
        const aliceOnFailure = jest.fn();
-        const alice = makeMockClient({
-            userId: "alice",
+        const [alice] = makeMockClient({
+            userId,
            deviceId: "ALICE",
            getLoginTokenEnabled: true,
            msc3882r0Only: false,
@@ -375,7 +444,7 @@ describe("Rendezvous", function () {

        // alice is already signs in and generates a code
        const aliceOnFailure = jest.fn();
-        const alice = makeMockClient({
+        const [alice] = makeMockClient({
            userId: "alice",
            deviceId: "ALICE",
            getLoginTokenEnabled: true,
@@ -436,7 +505,7 @@ describe("Rendezvous", function () {

        // alice is already signs in and generates a code
        const aliceOnFailure = jest.fn();
-        const alice = makeMockClient({
+        const [alice] = makeMockClient({
            userId: "alice",
            deviceId: "ALICE",
            getLoginTokenEnabled: true,
@@ -495,7 +564,7 @@ describe("Rendezvous", function () {
        await bobCompleteProm;
    });

-    async function completeLogin(devices: Record<string, Partial<DeviceInfo>>) {
+    async function completeLogin(devices: SimpleDeviceMap) {
        const aliceTransport = makeTransport("Alice", "https://test.rz/123456");
        const bobTransport = makeTransport("Bob", "https://test.rz/999999");
        transports.push(aliceTransport, bobTransport);
@@ -505,8 +574,8 @@ describe("Rendezvous", function () {
        // alice is already signs in and generates a code
        const aliceOnFailure = jest.fn();
        const aliceVerification = jest.fn();
-        const alice = makeMockClient({
-            userId: "alice",
+        const [alice, deviceMap] = makeMockClient({
+            userId,
            deviceId: "ALICE",
            getLoginTokenEnabled: true,
            msc3882r0Only: false,
@@ -575,13 +644,14 @@ describe("Rendezvous", function () {
            aliceRz,
            bobTransport,
            bobEcdh,
+            deviceMap,
        };
    }

    it("approve on existing device + verification", async function () {
        const { bobEcdh, aliceRz } = await completeLogin({
-            BOB: {
-                getFingerprint: () => "bbbb",
+            [userId]: {
+                BOB: "bbbb",
            },
        });
        const verifyProm = aliceRz.verifyNewDeviceOnExistingDevice();
@@ -607,33 +677,29 @@ describe("Rendezvous", function () {
    });

    it("device appears online within timeout", async function () {
-        const devices: Record<string, Partial<DeviceInfo>> = {};
-        const { aliceRz } = await completeLogin(devices);
-        // device appears after 1 second
+        const devices: SimpleDeviceMap = {};
+        const { aliceRz, deviceMap } = await completeLogin(devices);
+        // device appears before the timeout
        setTimeout(() => {
-            devices.BOB = {
-                getFingerprint: () => "bbbb",
-            };
+            deviceMap.get(userId)!.set("BOB", mockDevice(userId, "BOB", "bbbb"));
        }, 1000);
        await aliceRz.verifyNewDeviceOnExistingDevice(2000);
    });

    it("device appears online after timeout", async function () {
-        const devices: Record<string, Partial<DeviceInfo>> = {};
-        const { aliceRz } = await completeLogin(devices);
-        // device appears after 1 second
+        const devices: SimpleDeviceMap = {};
+        const { aliceRz, deviceMap } = await completeLogin(devices);
+        // device appears after the timeout
        setTimeout(() => {
-            devices.BOB = {
-                getFingerprint: () => "bbbb",
-            };
+            deviceMap.get(userId)!.set("BOB", mockDevice(userId, "BOB", "bbbb"));
        }, 1500);
        await expect(aliceRz.verifyNewDeviceOnExistingDevice(1000)).rejects.toThrow();
    });

    it("mismatched device key", async function () {
        const { aliceRz } = await completeLogin({
-            BOB: {
-                getFingerprint: () => "XXXX",
+            [userId]: {
+                BOB: "XXXX",
            },
        });
        await expect(aliceRz.verifyNewDeviceOnExistingDevice(1000)).rejects.toThrow(/different key/);
@@ -1460,7 +1460,7 @@ describe("Room", function () {
                it("should reset the unread count when our non-synthetic receipt points to the latest event", () => {
                    // Given a room with 2 events, and an unread count set.
                    room.client.isInitialSyncComplete = jest.fn().mockReturnValue(true);
-                    room.timeline = [event1, event2];
+                    jest.spyOn(room, "timeline", "get").mockReturnValue([event1, event2]);
                    room.setUnread(NotificationCountType.Total, 45);
                    room.setUnread(NotificationCountType.Highlight, 57);
                    // Sanity check:
@@ -1479,7 +1479,7 @@ describe("Room", function () {
                it("should not reset the unread count when someone else's receipt points to the latest event", () => {
                    // Given a room with 2 events, and an unread count set.
                    room.client.isInitialSyncComplete = jest.fn().mockReturnValue(true);
-                    room.timeline = [event1, event2];
+                    jest.spyOn(room, "timeline", "get").mockReturnValue([event1, event2]);
                    room.setUnread(NotificationCountType.Total, 45);
                    room.setUnread(NotificationCountType.Highlight, 57);
                    // Sanity check:
@@ -1498,7 +1498,7 @@ describe("Room", function () {
                it("should not reset the unread count when our non-synthetic receipt points to an earlier event", () => {
                    // Given a room with 2 events, and an unread count set.
                    room.client.isInitialSyncComplete = jest.fn().mockReturnValue(true);
-                    room.timeline = [event1, event2];
+                    jest.spyOn(room, "timeline", "get").mockReturnValue([event1, event2]);
                    room.setUnread(NotificationCountType.Total, 45);
                    room.setUnread(NotificationCountType.Highlight, 57);
                    // Sanity check:
@@ -1517,7 +1517,7 @@ describe("Room", function () {
                it("should not reset the unread count when our a synthetic receipt points to the latest event", () => {
                    // Given a room with 2 events, and an unread count set.
                    room.client.isInitialSyncComplete = jest.fn().mockReturnValue(true);
-                    room.timeline = [event1, event2];
+                    jest.spyOn(room, "timeline", "get").mockReturnValue([event1, event2]);
                    room.setUnread(NotificationCountType.Total, 45);
                    room.setUnread(NotificationCountType.Highlight, 57);
                    // Sanity check:
@@ -3315,7 +3315,7 @@ describe("Room", function () {
                                    return event1 === `eventId${i}` ? 1 : -1;
                                },
                                findEventById: jest.fn().mockReturnValue({} as MatrixEvent),
-                            } as unknown as EventTimelineSet);
+                            }) as unknown as EventTimelineSet;

                        expect(room.getEventReadUpTo(userA)).toEqual(`eventId${i}`);
                    }
@@ -3328,7 +3328,7 @@ describe("Room", function () {
                                ({
                                    compareEventOrdering: () => null,
                                    findEventById: jest.fn().mockReturnValue({} as MatrixEvent),
-                                } as unknown as EventTimelineSet);
+                                }) as unknown as EventTimelineSet;
                            room.getReadReceiptForUserId = (userId, ignore, receiptType): WrappedReceipt | null => {
                                if (receiptType === ReceiptType.ReadPrivate) {
                                    return { eventId: "eventId1", data: { ts: i === 1 ? 2 : 1 } } as WrappedReceipt;
@@ -3348,7 +3348,7 @@ describe("Room", function () {
                            ({
                                compareEventOrdering: () => null,
                                findEventById: jest.fn().mockReturnValue({} as MatrixEvent),
-                            } as unknown as EventTimelineSet);
+                            }) as unknown as EventTimelineSet;
                        room.getReadReceiptForUserId = (userId, ignore, receiptType): WrappedReceipt | null => {
                            if (receiptType === ReceiptType.Read) {
                                return { eventId: "eventId2", data: { ts: 1 } } as WrappedReceipt;
@@ -3366,7 +3366,7 @@ describe("Room", function () {
                            ({
                                compareEventOrdering: () => null,
                                findEventById: jest.fn().mockReturnValue({} as MatrixEvent),
-                            } as unknown as EventTimelineSet);
+                            }) as unknown as EventTimelineSet;
                    });

                    it("should give precedence to m.read.private", () => {
@@ -97,7 +97,10 @@ describe("KeyClaimManager", () => {
        await keyClaimManager.ensureSessionsForUsers(new LogSpan(logger, "test"), [u1, u2]);

        // check that all the calls were made
-        expect(olmMachine.getMissingSessions).toHaveBeenCalledWith([u1, u2]);
+        // We can't use directly toHaveBeenCalledWith because the UserId are cloned in the process.
+        const calledWith = olmMachine.getMissingSessions.mock.calls[0][0].map((u) => u.toString());
+        expect(calledWith).toEqual([u1.toString(), u2.toString()]);
+
        expect(fetchMock).toHaveFetched("https://example.com/_matrix/client/v3/keys/claim", {
            method: "POST",
            body: { k1: "v1" },
@@ -135,7 +138,10 @@ describe("KeyClaimManager", () => {

        // at this point, there should have been a single call to getMissingSessions, and a single fetch; and neither
        // call to ensureSessionsAsUsers should have completed
-        expect(olmMachine.getMissingSessions).toHaveBeenCalledWith([u1]);
+        // check that all the calls were made
+        // We can't use directly toHaveBeenCalledWith because the UserId are cloned in the process.
+        const calledWith = olmMachine.getMissingSessions.mock.calls[0][0].map((u) => u.toString());
+        expect(calledWith).toEqual([u1.toString()]);
        expect(olmMachine.getMissingSessions).toHaveBeenCalledTimes(1);
        expect(fetchMock).toHaveBeenCalledTimes(1);
        expect(req1Resolved).toBe(false);
@@ -147,7 +153,9 @@ describe("KeyClaimManager", () => {
        resolveMarkRequestAsSentCallback = await markRequestAsSentPromise;

        // the first request should now have completed, and we should have more calls and fetches
-        expect(olmMachine.getMissingSessions).toHaveBeenCalledWith([u2]);
+        // We can't use directly toHaveBeenCalledWith because the UserId are cloned in the process.
+        const calledWith2 = olmMachine.getMissingSessions.mock.calls[1][0].map((u) => u.toString());
+        expect(calledWith2).toEqual([u2.toString()]);
        expect(olmMachine.getMissingSessions).toHaveBeenCalledTimes(2);
        expect(fetchMock).toHaveBeenCalledTimes(2);
        expect(req1Resolved).toBe(true);
@@ -27,8 +27,9 @@ import {
    UploadSigningKeysRequest,
    ToDeviceRequest,
 } from "@matrix-org/matrix-sdk-crypto-wasm";
+import fetchMock from "fetch-mock-jest";

-import { TypedEventEmitter } from "../../../src/models/typed-event-emitter";
+import { TypedEventEmitter } from "../../../src";
 import { HttpApiEvent, HttpApiEventHandlerMap, IHttpOpts, MatrixHttpApi, UIAuthCallback } from "../../../src";
 import { OutgoingRequestProcessor } from "../../../src/rust-crypto/OutgoingRequestProcessor";
 import { defer } from "../../../src/utils";
@@ -274,4 +275,302 @@ describe("OutgoingRequestProcessor", () => {
        // ... and `makeOutgoingRequest` resolves satisfactorily
        await result;
    });
+
+    describe("Should retry requests", () => {
+        beforeEach(() => {
+            jest.useFakeTimers();
+
+            // here we use another httpApi instance in order to use fetchMock
+            const dummyEventEmitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
+            const httpApi = new MatrixHttpApi(dummyEventEmitter, {
+                baseUrl: "https://example.com",
+                prefix: "/_matrix",
+                onlyData: true,
+            });
+
+            processor = new OutgoingRequestProcessor(olmMachine, httpApi);
+        });
+
+        afterEach(() => {
+            jest.useRealTimers();
+            fetchMock.reset();
+        });
+
+        describe("Should retry on retryable errors", () => {
+            const retryableErrors: Array<[number, { status: number; body: { error: string } }]> = [
+                [429, { status: 429, body: { error: "Too Many Requests" } }],
+                [500, { status: 500, body: { error: "Internal Server Error" } }],
+                [502, { status: 502, body: { error: "Bad Gateway" } }],
+                [503, { status: 503, body: { error: "Service Unavailable" } }],
+                [504, { status: 504, body: { error: "Gateway timeout" } }],
+                [505, { status: 505, body: { error: "HTTP Version Not Supported" } }],
+                [506, { status: 506, body: { error: "Variant Also Negotiates" } }],
+                [507, { status: 507, body: { error: "Insufficient Storage" } }],
+                [508, { status: 508, body: { error: "Loop Detected" } }],
+                [510, { status: 510, body: { error: "Not Extended" } }],
+                [511, { status: 511, body: { error: "Network Authentication Required" } }],
+                [525, { status: 525, body: { error: "SSL Handshake Failed" } }],
+            ];
+            describe.each(retryableErrors)(`When status code is %s`, (_, error) => {
+                test.each(tests)(`for request of type %ss`, async (_, RequestClass, expectedMethod, expectedPath) => {
+                    // first, mock up a request as we might expect to receive it from the Rust layer ...
+                    const testBody = '{ "foo": "bar" }';
+                    const outgoingRequest = new RequestClass("1234", testBody);
+
+                    fetchMock.mock(expectedPath, error, { method: expectedMethod });
+
+                    const requestPromise = processor.makeOutgoingRequest(outgoingRequest);
+
+                    // Run all timers and wait for the request promise to resolve/reject
+                    await Promise.all([jest.runAllTimersAsync(), requestPromise.catch(() => {})]);
+
+                    await expect(requestPromise).rejects.toThrow();
+
+                    // Should have ultimately made 5 requests (1 initial + 4 retries)
+                    const calls = fetchMock.calls(expectedPath);
+                    expect(calls).toHaveLength(5);
+
+                    // The promise should have been rejected
+                    await expect(requestPromise).rejects.toThrow();
+                });
+            });
+        });
+
+        it("should not retry if M_TOO_LARGE", async () => {
+            const testBody = '{ "messages": { "user": {"device": "bar" }}}';
+            const outgoingRequest = new ToDeviceRequest("1234", "custom.type", "12345", testBody);
+
+            fetchMock.put("express:/_matrix/client/v3/sendToDevice/:type/:txnId", {
+                status: 502,
+                body: {
+                    errcode: "M_TOO_LARGE",
+                    error: "Request too large",
+                },
+            });
+
+            const requestPromise = processor.makeOutgoingRequest(outgoingRequest);
+
+            await Promise.all([requestPromise.catch(() => {}), jest.runAllTimersAsync()]);
+
+            await expect(requestPromise).rejects.toThrow();
+
+            const calls = fetchMock.calls("express:/_matrix/client/v3/sendToDevice/:type/:txnId");
+            expect(calls).toHaveLength(1);
+
+            // The promise should have been rejected
+            await expect(requestPromise).rejects.toThrow();
+        });
+
+        it("should retry on Failed to fetch connection errors", async () => {
+            let callCount = 0;
+            fetchMock.post("path:/_matrix/client/v3/keys/upload", (url, opts) => {
+                callCount++;
+                if (callCount == 2) {
+                    return {
+                        status: 200,
+                        body: "{}",
+                    };
+                } else {
+                    throw new Error("Failed to fetch");
+                }
+            });
+
+            const outgoingRequest = new KeysUploadRequest("1234", "{}");
+
+            const requestPromise = processor.makeOutgoingRequest(outgoingRequest);
+
+            await Promise.all([requestPromise, jest.runAllTimersAsync()]);
+
+            const calls = fetchMock.calls("path:/_matrix/client/v3/keys/upload");
+            expect(calls).toHaveLength(2);
+            expect(olmMachine.markRequestAsSent).toHaveBeenCalled();
+        });
+
+        it("should retry to send to-device", async () => {
+            let callCount = 0;
+            const testBody = '{ "messages": { "user": {"device": "bar" }}}';
+            const outgoingRequest = new ToDeviceRequest("1234", "custom.type", "12345", testBody);
+
+            fetchMock.put("express:/_matrix/client/v3/sendToDevice/:type/:txnId", (url, opts) => {
+                callCount++;
+                if (callCount == 2) {
+                    return {
+                        status: 200,
+                        body: "{}",
+                    };
+                } else {
+                    throw new Error("Failed to fetch");
+                }
+            });
+
+            const requestPromise = processor.makeOutgoingRequest(outgoingRequest);
+
+            await Promise.all([requestPromise, jest.runAllTimersAsync()]);
+
+            const calls = fetchMock.calls("express:/_matrix/client/v3/sendToDevice/:type/:txnId");
+            expect(calls).toHaveLength(2);
+            expect(olmMachine.markRequestAsSent).toHaveBeenCalled();
+        });
+
+        it("should retry to call with UIA", async () => {
+            let callCount = 0;
+            const testBody = '{ "foo": "bar" }';
+            const outgoingRequest = new UploadSigningKeysRequest(testBody);
+
+            fetchMock.post("path:/_matrix/client/v3/keys/device_signing/upload", (url, opts) => {
+                callCount++;
+                if (callCount == 2) {
+                    return {
+                        status: 200,
+                        body: "{}",
+                    };
+                } else {
+                    throw new Error("Failed to fetch");
+                }
+            });
+            const authCallback: UIAuthCallback<Object> = async (makeRequest) => {
+                return await makeRequest({ type: "test" });
+            };
+            const requestPromise = processor.makeOutgoingRequest(outgoingRequest, authCallback);
+
+            await Promise.all([requestPromise, jest.runAllTimersAsync()]);
+
+            const calls = fetchMock.calls("path:/_matrix/client/v3/keys/device_signing/upload");
+            expect(calls).toHaveLength(2);
+            // Will not mark as sent as it's a UIA request
+        });
+
+        it("should retry on respect server cool down on LIMIT_EXCEEDED", async () => {
+            const retryAfterMs = 5000;
+            let callCount = 0;
+
+            fetchMock.post("path:/_matrix/client/v3/keys/upload", (url, opts) => {
+                callCount++;
+                if (callCount == 2) {
+                    return {
+                        status: 200,
+                        body: "{}",
+                    };
+                } else {
+                    return {
+                        status: 429,
+                        body: {
+                            errcode: "M_LIMIT_EXCEEDED",
+                            error: "Too many requests",
+                            retry_after_ms: retryAfterMs,
+                        },
+                    };
+                }
+            });
+
+            const outgoingRequest = new KeysUploadRequest("1234", "{}");
+
+            const requestPromise = processor.makeOutgoingRequest(outgoingRequest);
+
+            // advanced by less than the retryAfterMs
+            await jest.advanceTimersByTimeAsync(retryAfterMs - 1000);
+
+            // should not have made a second request yet
+            {
+                const calls = fetchMock.calls("path:/_matrix/client/v3/keys/upload");
+                expect(calls).toHaveLength(1);
+            }
+
+            // advanced by the remaining time
+            await jest.advanceTimersByTimeAsync(retryAfterMs + 1000);
+
+            await requestPromise;
+
+            const calls = fetchMock.calls("path:/_matrix/client/v3/keys/upload");
+            expect(calls).toHaveLength(2);
+            expect(olmMachine.markRequestAsSent).toHaveBeenCalled();
+        });
+
+        const nonRetryableErrors: Array<[number, { status: number; body: { errcode: string } }]> = [
+            [400, { status: 400, body: { errcode: "Bad Request" } }],
+            [401, { status: 401, body: { errcode: "M_UNKNOWN_TOKEN" } }],
+            [403, { status: 403, body: { errcode: "M_FORBIDDEN" } }],
+        ];
+
+        describe.each(nonRetryableErrors)("Should not retry all sort of errors", (_, error) => {
+            test.each(tests)("for %ss", async (_, RequestClass, expectedMethod, expectedPath) => {
+                const testBody = '{ "foo": "bar" }';
+                const outgoingRequest = new RequestClass("1234", testBody);
+
+                // @ts-ignore to avoid having to do if else to switch the method (.put/.post)
+                fetchMock[expectedMethod.toLowerCase()](expectedPath, {
+                    status: error.status,
+                    body: error.body,
+                });
+
+                const requestPromise = processor.makeOutgoingRequest(outgoingRequest);
+
+                // Run all timers and wait for the request promise to resolve/reject
+                await Promise.all([jest.runAllTimersAsync(), requestPromise.catch(() => {})]);
+
+                await expect(requestPromise).rejects.toThrow();
+
+                // Should have only tried once
+                const calls = fetchMock.calls(expectedPath);
+                expect(calls).toHaveLength(1);
+
+                await expect(requestPromise).rejects.toThrow();
+            });
+        });
+
+        describe("Should not retry client timeouts", () => {
+            test.each(tests)("for %ss", async (_, RequestClass, expectedMethod, expectedPath) => {
+                const testBody = '{ "foo": "bar" }';
+                const outgoingRequest = new RequestClass("1234", testBody);
+
+                // @ts-ignore to avoid having to do if else to switch the method (.put/.post)
+                fetchMock[expectedMethod.toLowerCase()](expectedPath, () => {
+                    // This is what a client timeout error will throw
+                    throw new DOMException("The user aborted a request.", "AbortError");
+                });
+
+                const requestPromise = processor.makeOutgoingRequest(outgoingRequest);
+
+                // Run all timers and wait for the request promise to resolve/reject
+                await Promise.all([jest.runAllTimersAsync(), requestPromise.catch(() => {})]);
+
+                await expect(requestPromise).rejects.toThrow();
+
+                // Should have only tried once
+                const calls = fetchMock.calls(expectedPath);
+                expect(calls).toHaveLength(1);
+                await expect(requestPromise).rejects.toThrow();
+            });
+        });
+
+        describe("Should retry until it works", () => {
+            it.each([1, 2, 3, 4])("should succeed if the call number %s is ok", async (successfulCall) => {
+                let callCount = 0;
+                fetchMock.post("path:/_matrix/client/v3/keys/upload", (url, opts) => {
+                    callCount++;
+                    if (callCount == successfulCall) {
+                        return {
+                            status: 200,
+                            body: "{}",
+                        };
+                    } else {
+                        return {
+                            status: 500,
+                            body: { error: "Internal server error" },
+                        };
+                    }
+                });
+
+                const outgoingRequest = new KeysUploadRequest("1234", "{}");
+
+                const requestPromise = processor.makeOutgoingRequest(outgoingRequest);
+
+                await Promise.all([requestPromise, jest.runAllTimersAsync()]);
+
+                const calls = fetchMock.calls("path:/_matrix/client/v3/keys/upload");
+                expect(calls).toHaveLength(successfulCall);
+                expect(olmMachine.markRequestAsSent).toHaveBeenCalled();
+            });
+        });
+    });
 });
@@ -16,16 +16,169 @@
 * /
 */

-import { HistoryVisibility as RustHistoryVisibility } from "@matrix-org/matrix-sdk-crypto-wasm";
+import {
+    Curve25519PublicKey,
+    Ed25519PublicKey,
+    HistoryVisibility as RustHistoryVisibility,
+    IdentityKeys,
+    OlmMachine,
+} from "@matrix-org/matrix-sdk-crypto-wasm";
+import { Mocked } from "jest-mock";

-import { HistoryVisibility } from "../../../src";
-import { toRustHistoryVisibility } from "../../../src/rust-crypto/RoomEncryptor";
+import { HistoryVisibility, MatrixEvent, Room, RoomMember } from "../../../src";
+import { RoomEncryptor, toRustHistoryVisibility } from "../../../src/rust-crypto/RoomEncryptor";
+import { KeyClaimManager } from "../../../src/rust-crypto/KeyClaimManager";
+import { defer } from "../../../src/utils";
+import { OutgoingRequestsManager } from "../../../src/rust-crypto/OutgoingRequestsManager";

-it.each([
-    [HistoryVisibility.Invited, RustHistoryVisibility.Invited],
-    [HistoryVisibility.Joined, RustHistoryVisibility.Joined],
-    [HistoryVisibility.Shared, RustHistoryVisibility.Shared],
-    [HistoryVisibility.WorldReadable, RustHistoryVisibility.WorldReadable],
-])("JS HistoryVisibility to Rust HistoryVisibility: converts %s to %s", (historyVisibility, expected) => {
-    expect(toRustHistoryVisibility(historyVisibility)).toBe(expected);
+describe("RoomEncryptor", () => {
+    describe("History Visibility", () => {
+        it.each([
+            [HistoryVisibility.Invited, RustHistoryVisibility.Invited],
+            [HistoryVisibility.Joined, RustHistoryVisibility.Joined],
+            [HistoryVisibility.Shared, RustHistoryVisibility.Shared],
+            [HistoryVisibility.WorldReadable, RustHistoryVisibility.WorldReadable],
+        ])("JS HistoryVisibility to Rust HistoryVisibility: converts %s to %s", (historyVisibility, expected) => {
+            expect(toRustHistoryVisibility(historyVisibility)).toBe(expected);
+        });
+    });
+
+    describe("RoomEncryptor", () => {
+        /** The room encryptor under test */
+        let roomEncryptor: RoomEncryptor;
+
+        let mockOlmMachine: Mocked<OlmMachine>;
+        let mockKeyClaimManager: Mocked<KeyClaimManager>;
+        let mockOutgoingRequestManager: Mocked<OutgoingRequestsManager>;
+        let mockRoom: Mocked<Room>;
+
+        const mockRoomMember = {
+            userId: "@alice:example.org",
+            membership: "join",
+        } as unknown as Mocked<RoomMember>;
+
+        function createMockEvent(text: string): Mocked<MatrixEvent> {
+            return {
+                getTxnId: jest.fn().mockReturnValue(""),
+                getType: jest.fn().mockReturnValue("m.room.message"),
+                getContent: jest.fn().mockReturnValue({
+                    body: text,
+                    msgtype: "m.text",
+                }),
+                makeEncrypted: jest.fn().mockReturnValue(undefined),
+            } as unknown as Mocked<MatrixEvent>;
+        }
+
+        beforeEach(() => {
+            mockOlmMachine = {
+                identityKeys: {
+                    curve25519: {
+                        toBase64: jest.fn().mockReturnValue("curve25519"),
+                    } as unknown as Curve25519PublicKey,
+                    ed25519: {
+                        toBase64: jest.fn().mockReturnValue("ed25519"),
+                    } as unknown as Ed25519PublicKey,
+                } as unknown as Mocked<IdentityKeys>,
+                shareRoomKey: jest.fn(),
+                updateTrackedUsers: jest.fn().mockResolvedValue(undefined),
+                encryptRoomEvent: jest.fn().mockResolvedValue("{}"),
+            } as unknown as Mocked<OlmMachine>;
+
+            mockKeyClaimManager = {
+                ensureSessionsForUsers: jest.fn(),
+            } as unknown as Mocked<KeyClaimManager>;
+
+            mockOutgoingRequestManager = {
+                doProcessOutgoingRequests: jest.fn().mockResolvedValue(undefined),
+            } as unknown as Mocked<OutgoingRequestsManager>;
+
+            mockRoom = {
+                roomId: "!foo:example.org",
+                getJoinedMembers: jest.fn().mockReturnValue([mockRoomMember]),
+                getEncryptionTargetMembers: jest.fn().mockReturnValue([mockRoomMember]),
+                shouldEncryptForInvitedMembers: jest.fn().mockReturnValue(true),
+                getHistoryVisibility: jest.fn().mockReturnValue(HistoryVisibility.Invited),
+                getBlacklistUnverifiedDevices: jest.fn().mockReturnValue(false),
+            } as unknown as Mocked<Room>;
+
+            roomEncryptor = new RoomEncryptor(
+                mockOlmMachine,
+                mockKeyClaimManager,
+                mockOutgoingRequestManager,
+                mockRoom,
+                { algorithm: "m.megolm.v1.aes-sha2" },
+            );
+        });
+
+        it("should ensure that there is only one shareRoomKey at a time", async () => {
+            const deferredShare = defer<void>();
+            const insideOlmShareRoom = defer<void>();
+
+            mockOlmMachine.shareRoomKey.mockImplementationOnce(async () => {
+                insideOlmShareRoom.resolve();
+                await deferredShare.promise;
+            });
+
+            roomEncryptor.prepareForEncryption(false);
+            await insideOlmShareRoom.promise;
+
+            // call several times more
+            roomEncryptor.prepareForEncryption(false);
+            roomEncryptor.encryptEvent(createMockEvent("Hello"), false);
+            roomEncryptor.prepareForEncryption(false);
+            roomEncryptor.encryptEvent(createMockEvent("World"), false);
+
+            expect(mockOlmMachine.shareRoomKey).toHaveBeenCalledTimes(1);
+
+            deferredShare.resolve();
+            await roomEncryptor.prepareForEncryption(false);
+
+            // should have been called again
+            expect(mockOlmMachine.shareRoomKey).toHaveBeenCalledTimes(6);
+        });
+
+        // Regression test for https://github.com/element-hq/element-web/issues/26684
+        it("Should maintain order of encryption requests", async () => {
+            const firstTargetMembers = defer<void>();
+            const secondTargetMembers = defer<void>();
+
+            mockOlmMachine.shareRoomKey.mockResolvedValue(undefined);
+
+            // Hook into this method to demonstrate the race condition
+            mockRoom.getEncryptionTargetMembers
+                .mockImplementationOnce(async () => {
+                    await firstTargetMembers.promise;
+                    return [mockRoomMember];
+                })
+                .mockImplementationOnce(async () => {
+                    await secondTargetMembers.promise;
+                    return [mockRoomMember];
+                });
+
+            let firstMessageFinished: string | null = null;
+
+            const firstRequest = roomEncryptor.encryptEvent(createMockEvent("Hello"), false);
+            const secondRequest = roomEncryptor.encryptEvent(createMockEvent("Edit of Hello"), false);
+
+            firstRequest.then(() => {
+                if (firstMessageFinished === null) {
+                    firstMessageFinished = "hello";
+                }
+            });
+
+            secondRequest.then(() => {
+                if (firstMessageFinished === null) {
+                    firstMessageFinished = "edit";
+                }
+            });
+
+            // suppose the second getEncryptionTargetMembers call returns first
+            secondTargetMembers.resolve();
+            firstTargetMembers.resolve();
+
+            await Promise.all([firstRequest, secondRequest]);
+
+            expect(firstMessageFinished).toBe("hello");
+        });
+    });
 });
@@ -0,0 +1,144 @@
+import { Mocked } from "jest-mock";
+import fetchMock from "fetch-mock-jest";
+import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-wasm";
+
+import { CryptoEvent, HttpApiEvent, HttpApiEventHandlerMap, MatrixHttpApi, TypedEventEmitter } from "../../../src";
+import { OutgoingRequestProcessor } from "../../../src/rust-crypto/OutgoingRequestProcessor";
+import * as testData from "../../test-utils/test-data";
+import * as TestData from "../../test-utils/test-data";
+import { IKeyBackup } from "../../../src/crypto/backup";
+import { IKeyBackupSession } from "../../../src/crypto/keybackup";
+import { RustBackupManager } from "../../../src/rust-crypto/backup";
+
+describe("Upload keys to backup", () => {
+    /** The backup manager under test */
+    let rustBackupManager: RustBackupManager;
+
+    let mockOlmMachine: Mocked<RustSdkCryptoJs.OlmMachine>;
+
+    let outgoingRequestProcessor: Mocked<OutgoingRequestProcessor>;
+
+    const httpAPi = new MatrixHttpApi(new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>(), {
+        baseUrl: "http://server/",
+        prefix: "",
+        onlyData: true,
+    });
+
+    let idGenerator = 0;
+    function mockBackupRequest(keyCount: number): RustSdkCryptoJs.KeysBackupRequest {
+        const requestBody: IKeyBackup = {
+            rooms: {
+                "!room1:server": {
+                    sessions: {},
+                },
+            },
+        };
+        for (let i = 0; i < keyCount; i++) {
+            requestBody.rooms["!room1:server"].sessions["session" + i] = {} as IKeyBackupSession;
+        }
+        return {
+            id: "id" + idGenerator++,
+            body: JSON.stringify(requestBody),
+        } as unknown as Mocked<RustSdkCryptoJs.KeysBackupRequest>;
+    }
+
+    beforeEach(async () => {
+        jest.useFakeTimers();
+        idGenerator = 0;
+
+        mockOlmMachine = {
+            getBackupKeys: jest.fn().mockResolvedValue({
+                backupVersion: TestData.SIGNED_BACKUP_DATA.version!,
+                decryptionKey: RustSdkCryptoJs.BackupDecryptionKey.fromBase64(TestData.BACKUP_DECRYPTION_KEY_BASE64),
+            } as unknown as RustSdkCryptoJs.BackupKeys),
+            backupRoomKeys: jest.fn(),
+            isBackupEnabled: jest.fn().mockResolvedValue(true),
+            enableBackupV1: jest.fn(),
+            verifyBackup: jest.fn().mockResolvedValue({
+                trusted: jest.fn().mockResolvedValue(true),
+            } as unknown as RustSdkCryptoJs.SignatureVerification),
+            roomKeyCounts: jest.fn(),
+        } as unknown as Mocked<RustSdkCryptoJs.OlmMachine>;
+
+        outgoingRequestProcessor = {
+            makeOutgoingRequest: jest.fn(),
+        } as unknown as Mocked<OutgoingRequestProcessor>;
+
+        rustBackupManager = new RustBackupManager(mockOlmMachine, httpAPi, outgoingRequestProcessor);
+
+        fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);
+    });
+
+    afterEach(() => {
+        fetchMock.reset();
+        jest.useRealTimers();
+        jest.resetAllMocks();
+    });
+
+    it("Should call expensive roomKeyCounts only once per loop", async () => {
+        const remainingEmitted: number[] = [];
+
+        const zeroRemainingWasEmitted = new Promise<void>((resolve) => {
+            rustBackupManager.on(CryptoEvent.KeyBackupSessionsRemaining, (count) => {
+                remainingEmitted.push(count);
+                if (count == 0) {
+                    resolve();
+                }
+            });
+        });
+
+        // We want several batch of keys to check that we don't call expensive room key count several times
+        mockOlmMachine.backupRoomKeys
+            .mockResolvedValueOnce(mockBackupRequest(100))
+            .mockResolvedValueOnce(mockBackupRequest(100))
+            .mockResolvedValueOnce(mockBackupRequest(100))
+            .mockResolvedValueOnce(mockBackupRequest(100))
+            .mockResolvedValueOnce(mockBackupRequest(100))
+            .mockResolvedValueOnce(mockBackupRequest(100))
+            .mockResolvedValueOnce(mockBackupRequest(2))
+            .mockResolvedValue(null);
+
+        mockOlmMachine.roomKeyCounts.mockResolvedValue({
+            total: 602,
+            // First iteration won't call roomKeyCounts(); it will be called on the second iteration after 200 keys have been saved.
+            backedUp: 200,
+        });
+
+        await rustBackupManager.checkKeyBackupAndEnable(false);
+        await jest.runAllTimersAsync();
+
+        await zeroRemainingWasEmitted;
+
+        expect(outgoingRequestProcessor.makeOutgoingRequest).toHaveBeenCalledTimes(7);
+        expect(mockOlmMachine.roomKeyCounts).toHaveBeenCalledTimes(1);
+
+        // check event emission
+        expect(remainingEmitted[0]).toEqual(402);
+        expect(remainingEmitted[1]).toEqual(302);
+        expect(remainingEmitted[2]).toEqual(202);
+        expect(remainingEmitted[3]).toEqual(102);
+        expect(remainingEmitted[4]).toEqual(2);
+        expect(remainingEmitted[5]).toEqual(0);
+    });
+
+    it("Should not call expensive roomKeyCounts when only one iteration is needed", async () => {
+        const zeroRemainingWasEmitted = new Promise<void>((resolve) => {
+            rustBackupManager.on(CryptoEvent.KeyBackupSessionsRemaining, (count) => {
+                if (count == 0) {
+                    resolve();
+                }
+            });
+        });
+
+        // Only returns 2 keys on the first call, then none.
+        mockOlmMachine.backupRoomKeys.mockResolvedValueOnce(mockBackupRequest(2)).mockResolvedValue(null);
+
+        await rustBackupManager.checkKeyBackupAndEnable(false);
+        await jest.runAllTimersAsync();
+
+        await zeroRemainingWasEmitted;
+
+        expect(outgoingRequestProcessor.makeOutgoingRequest).toHaveBeenCalledTimes(1);
+        expect(mockOlmMachine.roomKeyCounts).toHaveBeenCalledTimes(0);
+    });
+});
@@ -15,7 +15,15 @@ limitations under the License.
 */

 import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-wasm";
-import { KeysQueryRequest, OlmMachine } from "@matrix-org/matrix-sdk-crypto-wasm";
+import {
+    BaseMigrationData,
+    KeysQueryRequest,
+    Migration,
+    OlmMachine,
+    PickledInboundGroupSession,
+    PickledSession,
+    StoreHandle,
+} from "@matrix-org/matrix-sdk-crypto-wasm";
 import { mocked, Mocked } from "jest-mock";
 import fetchMock from "fetch-mock-jest";

@@ -25,6 +33,7 @@ import {
    CryptoEvent,
    Device,
    DeviceVerification,
+    encodeBase64,
    HttpApiEvent,
    HttpApiEventHandlerMap,
    IHttpOpts,
@@ -32,13 +41,20 @@ import {
    MatrixClient,
    MatrixEvent,
    MatrixHttpApi,
+    MemoryCryptoStore,
    TypedEventEmitter,
 } from "../../../src";
 import { mkEvent } from "../../test-utils/test-utils";
 import { CryptoBackend } from "../../../src/common-crypto/CryptoBackend";
-import { IEventDecryptionResult } from "../../../src/@types/crypto";
+import { IEventDecryptionResult, IMegolmSessionData } from "../../../src/@types/crypto";
 import { OutgoingRequestProcessor } from "../../../src/rust-crypto/OutgoingRequestProcessor";
-import { ServerSideSecretStorage } from "../../../src/secret-storage";
+import {
+    AccountDataClient,
+    AddSecretStorageKeyOpts,
+    SecretStorageCallbacks,
+    ServerSideSecretStorage,
+    ServerSideSecretStorageImpl,
+} from "../../../src/secret-storage";
 import {
    CryptoCallbacks,
    EventShieldColour,
@@ -51,11 +67,20 @@ import * as testData from "../../test-utils/test-data";
 import { defer } from "../../../src/utils";
 import { logger } from "../../../src/logger";
 import { OutgoingRequestsManager } from "../../../src/rust-crypto/OutgoingRequestsManager";
+import { ClientEvent, ClientEventHandlerMap } from "../../../src/client";
 import { Curve25519AuthData } from "../../../src/crypto-api/keybackup";
+import { encryptAES } from "../../../src/crypto/aes";
+import { CryptoStore, SecretStorePrivateKeys } from "../../../src/crypto/store/base";

 const TEST_USER = "@alice:example.com";
 const TEST_DEVICE_ID = "TEST_DEVICE";

+beforeAll(async () => {
+    // Load the WASM upfront, before any of the tests. This can take some time, and doing it here means that it gets
+    // a separate timeout.
+    await RustSdkCryptoJs.initAsync();
+}, 15000);
+
 afterEach(() => {
    fetchMock.reset();
    jest.restoreAllMocks();
@@ -66,71 +91,287 @@ describe("initRustCrypto", () => {
        return {
            registerRoomKeyUpdatedCallback: jest.fn(),
            registerUserIdentityUpdatedCallback: jest.fn(),
-            getSecretsFromInbox: jest.fn().mockResolvedValue(["dGhpc2lzYWZha2VzZWNyZXQ="]),
+            getSecretsFromInbox: jest.fn().mockResolvedValue([]),
            deleteSecretsFromInbox: jest.fn(),
            registerReceiveSecretCallback: jest.fn(),
+            registerDevicesUpdatedCallback: jest.fn(),
            outgoingRequests: jest.fn(),
+            isBackupEnabled: jest.fn().mockResolvedValue(false),
+            verifyBackup: jest.fn().mockResolvedValue({ trusted: jest.fn().mockReturnValue(false) }),
+            getBackupKeys: jest.fn(),
        } as unknown as Mocked<OlmMachine>;
    }

    it("passes through the store params", async () => {
+        const mockStore = { free: jest.fn() } as unknown as StoreHandle;
+        jest.spyOn(StoreHandle, "open").mockResolvedValue(mockStore);
+
        const testOlmMachine = makeTestOlmMachine();
-        jest.spyOn(OlmMachine, "initialize").mockResolvedValue(testOlmMachine);
+        jest.spyOn(OlmMachine, "initFromStore").mockResolvedValue(testOlmMachine);

-        await initRustCrypto(
+        await initRustCrypto({
            logger,
-            {} as MatrixClient["http"],
-            TEST_USER,
-            TEST_DEVICE_ID,
-            {} as ServerSideSecretStorage,
-            {} as CryptoCallbacks,
-            "storePrefix",
-            "storePassphrase",
-        );
+            http: {} as MatrixClient["http"],
+            userId: TEST_USER,
+            deviceId: TEST_DEVICE_ID,
+            secretStorage: {} as ServerSideSecretStorage,
+            cryptoCallbacks: {} as CryptoCallbacks,
+            storePrefix: "storePrefix",
+            storePassphrase: "storePassphrase",
+        });

-        expect(OlmMachine.initialize).toHaveBeenCalledWith(
-            expect.anything(),
-            expect.anything(),
-            "storePrefix",
-            "storePassphrase",
-        );
+        expect(StoreHandle.open).toHaveBeenCalledWith("storePrefix", "storePassphrase");
+        expect(OlmMachine.initFromStore).toHaveBeenCalledWith(expect.anything(), expect.anything(), mockStore);
    });

    it("suppresses the storePassphrase if storePrefix is unset", async () => {
+        const mockStore = { free: jest.fn() } as unknown as StoreHandle;
+        jest.spyOn(StoreHandle, "open").mockResolvedValue(mockStore);
+
        const testOlmMachine = makeTestOlmMachine();
-        jest.spyOn(OlmMachine, "initialize").mockResolvedValue(testOlmMachine);
+        jest.spyOn(OlmMachine, "initFromStore").mockResolvedValue(testOlmMachine);

-        await initRustCrypto(
+        await initRustCrypto({
            logger,
-            {} as MatrixClient["http"],
-            TEST_USER,
-            TEST_DEVICE_ID,
-            {} as ServerSideSecretStorage,
-            {} as CryptoCallbacks,
-            null,
-            "storePassphrase",
-        );
+            http: {} as MatrixClient["http"],
+            userId: TEST_USER,
+            deviceId: TEST_DEVICE_ID,
+            secretStorage: {} as ServerSideSecretStorage,
+            cryptoCallbacks: {} as CryptoCallbacks,
+            storePrefix: null,
+            storePassphrase: "storePassphrase",
+        });

-        expect(OlmMachine.initialize).toHaveBeenCalledWith(expect.anything(), expect.anything(), undefined, undefined);
+        expect(StoreHandle.open).toHaveBeenCalledWith(undefined, undefined);
+        expect(OlmMachine.initFromStore).toHaveBeenCalledWith(expect.anything(), expect.anything(), mockStore);
    });

    it("Should get secrets from inbox on start", async () => {
-        const testOlmMachine = makeTestOlmMachine() as OlmMachine;
-        jest.spyOn(OlmMachine, "initialize").mockResolvedValue(testOlmMachine);
+        const mockStore = { free: jest.fn() } as unknown as StoreHandle;
+        jest.spyOn(StoreHandle, "open").mockResolvedValue(mockStore);

-        await initRustCrypto(
+        const testOlmMachine = makeTestOlmMachine();
+        jest.spyOn(OlmMachine, "initFromStore").mockResolvedValue(testOlmMachine);
+
+        await initRustCrypto({
            logger,
-            {} as MatrixClient["http"],
-            TEST_USER,
-            TEST_DEVICE_ID,
-            {} as ServerSideSecretStorage,
-            {} as CryptoCallbacks,
-            "storePrefix",
-            "storePassphrase",
-        );
+            http: {} as MatrixClient["http"],
+            userId: TEST_USER,
+            deviceId: TEST_DEVICE_ID,
+            secretStorage: {} as ServerSideSecretStorage,
+            cryptoCallbacks: {} as CryptoCallbacks,
+            storePrefix: "storePrefix",
+            storePassphrase: "storePassphrase",
+        });

        expect(testOlmMachine.getSecretsFromInbox).toHaveBeenCalledWith("m.megolm_backup.v1");
    });
+
+    describe("libolm migration", () => {
+        let mockStore: RustSdkCryptoJs.StoreHandle;
+
+        beforeEach(() => {
+            // Stub out a bunch of stuff in the Rust library
+            mockStore = { free: jest.fn() } as unknown as StoreHandle;
+            jest.spyOn(StoreHandle, "open").mockResolvedValue(mockStore);
+
+            jest.spyOn(Migration, "migrateBaseData").mockResolvedValue(undefined);
+            jest.spyOn(Migration, "migrateOlmSessions").mockResolvedValue(undefined);
+            jest.spyOn(Migration, "migrateMegolmSessions").mockResolvedValue(undefined);
+
+            const testOlmMachine = makeTestOlmMachine();
+            jest.spyOn(OlmMachine, "initFromStore").mockResolvedValue(testOlmMachine);
+        });
+
+        it("migrates data from a legacy crypto store", async () => {
+            const PICKLE_KEY = "pickle1234";
+            const legacyStore = new MemoryCryptoStore();
+
+            // Populate the legacy store with some test data
+            const storeSecretKey = (type: string, key: string) =>
+                encryptAndStoreSecretKey(type, new TextEncoder().encode(key), PICKLE_KEY, legacyStore);
+
+            await legacyStore.storeAccount({}, "not a real account");
+            await storeSecretKey("m.megolm_backup.v1", "backup key");
+            await storeSecretKey("master", "master key");
+            await storeSecretKey("self_signing", "ssk");
+            await storeSecretKey("user_signing", "usk");
+            const nDevices = 6;
+            const nSessionsPerDevice = 10;
+            createSessions(legacyStore, nDevices, nSessionsPerDevice);
+            createMegolmSessions(legacyStore, nDevices, nSessionsPerDevice);
+            await legacyStore.markSessionsNeedingBackup([{ senderKey: pad43("device5"), sessionId: "session5" }]);
+
+            fetchMock.get("path:/_matrix/client/v3/room_keys/version", { version: "45" });
+
+            function legacyMigrationProgressListener(progress: number, total: number): void {
+                logger.log(`migrated ${progress} of ${total}`);
+            }
+
+            await initRustCrypto({
+                logger,
+                http: makeMatrixHttpApi(),
+                userId: TEST_USER,
+                deviceId: TEST_DEVICE_ID,
+                secretStorage: {} as ServerSideSecretStorage,
+                cryptoCallbacks: {} as CryptoCallbacks,
+                storePrefix: "storePrefix",
+                storePassphrase: "storePassphrase",
+                legacyCryptoStore: legacyStore,
+                legacyPickleKey: PICKLE_KEY,
+                legacyMigrationProgressListener,
+            });
+
+            // Check that the migration functions were correctly called
+            expect(Migration.migrateBaseData).toHaveBeenCalledWith(
+                expect.any(BaseMigrationData),
+                new Uint8Array(Buffer.from(PICKLE_KEY)),
+                mockStore,
+            );
+            const data = mocked(Migration.migrateBaseData).mock.calls[0][0];
+            expect(data.pickledAccount).toEqual("not a real account");
+            expect(data.userId!.toString()).toEqual(TEST_USER);
+            expect(data.deviceId!.toString()).toEqual(TEST_DEVICE_ID);
+            expect(atob(data.backupRecoveryKey!)).toEqual("backup key");
+            expect(data.backupVersion).toEqual("45");
+            expect(atob(data.privateCrossSigningMasterKey!)).toEqual("master key");
+            expect(atob(data.privateCrossSigningUserSigningKey!)).toEqual("usk");
+            expect(atob(data.privateCrossSigningSelfSigningKey!)).toEqual("ssk");
+
+            expect(Migration.migrateOlmSessions).toHaveBeenCalledTimes(2);
+            expect(Migration.migrateOlmSessions).toHaveBeenCalledWith(
+                expect.any(Array),
+                new Uint8Array(Buffer.from(PICKLE_KEY)),
+                mockStore,
+            );
+            // First call should have 50 entries; second should have 10
+            const sessions1: PickledSession[] = mocked(Migration.migrateOlmSessions).mock.calls[0][0];
+            expect(sessions1.length).toEqual(50);
+            const sessions2: PickledSession[] = mocked(Migration.migrateOlmSessions).mock.calls[1][0];
+            expect(sessions2.length).toEqual(10);
+            const sessions = [...sessions1, ...sessions2];
+            for (let i = 0; i < nDevices; i++) {
+                for (let j = 0; j < nSessionsPerDevice; j++) {
+                    const session = sessions[i * nSessionsPerDevice + j];
+                    expect(session.senderKey).toEqual(`device${i}`);
+                    expect(session.pickle).toEqual(`session${i}.${j}`);
+                    expect(session.creationTime).toEqual(new Date(1000));
+                    expect(session.lastUseTime).toEqual(new Date(1000));
+                }
+            }
+
+            expect(Migration.migrateMegolmSessions).toHaveBeenCalledTimes(2);
+            expect(Migration.migrateMegolmSessions).toHaveBeenCalledWith(
+                expect.any(Array),
+                new Uint8Array(Buffer.from(PICKLE_KEY)),
+                mockStore,
+            );
+            // First call should have 50 entries; second should have 10
+            const megolmSessions1: PickledInboundGroupSession[] = mocked(Migration.migrateMegolmSessions).mock
+                .calls[0][0];
+            expect(megolmSessions1.length).toEqual(50);
+            const megolmSessions2: PickledInboundGroupSession[] = mocked(Migration.migrateMegolmSessions).mock
+                .calls[1][0];
+            expect(megolmSessions2.length).toEqual(10);
+            const megolmSessions = [...megolmSessions1, ...megolmSessions2];
+            for (let i = 0; i < nDevices; i++) {
+                for (let j = 0; j < nSessionsPerDevice; j++) {
+                    const session = megolmSessions[i * nSessionsPerDevice + j];
+                    expect(session.senderKey).toEqual(pad43(`device${i}`));
+                    expect(session.pickle).toEqual("sessionPickle");
+                    expect(session.roomId!.toString()).toEqual("!room:id");
+                    expect(session.senderSigningKey).toEqual("sender_signing_key");
+
+                    // only one of the sessions needs backing up
+                    expect(session.backedUp).toEqual(i !== 5 || j !== 5);
+                }
+            }
+        }, 10000);
+
+        it("handles megolm sessions with no `keysClaimed`", async () => {
+            const legacyStore = new MemoryCryptoStore();
+            legacyStore.storeAccount({}, "not a real account");
+
+            legacyStore.storeEndToEndInboundGroupSession(
+                pad43(`device1`),
+                `session1`,
+                {
+                    forwardingCurve25519KeyChain: [],
+                    room_id: "!room:id",
+                    session: "sessionPickle",
+                },
+                undefined,
+            );
+
+            const PICKLE_KEY = "pickle1234";
+            await initRustCrypto({
+                logger,
+                http: makeMatrixHttpApi(),
+                userId: TEST_USER,
+                deviceId: TEST_DEVICE_ID,
+                secretStorage: {} as ServerSideSecretStorage,
+                cryptoCallbacks: {} as CryptoCallbacks,
+                storePrefix: "storePrefix",
+                storePassphrase: "storePassphrase",
+                legacyCryptoStore: legacyStore,
+                legacyPickleKey: PICKLE_KEY,
+            });
+
+            expect(Migration.migrateMegolmSessions).toHaveBeenCalledTimes(1);
+            expect(Migration.migrateMegolmSessions).toHaveBeenCalledWith(
+                expect.any(Array),
+                new Uint8Array(Buffer.from(PICKLE_KEY)),
+                mockStore,
+            );
+            const megolmSessions: PickledInboundGroupSession[] = mocked(Migration.migrateMegolmSessions).mock
+                .calls[0][0];
+            expect(megolmSessions.length).toEqual(1);
+            const session = megolmSessions[0];
+            expect(session.senderKey).toEqual(pad43(`device1`));
+            expect(session.pickle).toEqual("sessionPickle");
+            expect(session.roomId!.toString()).toEqual("!room:id");
+            expect(session.senderSigningKey).toBe(undefined);
+        }, 10000);
+
+        async function encryptAndStoreSecretKey(type: string, key: Uint8Array, pickleKey: string, store: CryptoStore) {
+            const encryptedKey = await encryptAES(encodeBase64(key), Buffer.from(pickleKey), type);
+            store.storeSecretStorePrivateKey(undefined, type as keyof SecretStorePrivateKeys, encryptedKey);
+        }
+
+        /** Create a bunch of fake Olm sessions and stash them in the DB. */
+        function createSessions(store: CryptoStore, nDevices: number, nSessionsPerDevice: number) {
+            for (let i = 0; i < nDevices; i++) {
+                for (let j = 0; j < nSessionsPerDevice; j++) {
+                    const sessionData = {
+                        deviceKey: `device${i}`,
+                        sessionId: `session${j}`,
+                        session: `session${i}.${j}`,
+                        lastReceivedMessageTs: 1000,
+                    };
+                    store.storeEndToEndSession(`device${i}`, `session${j}`, sessionData, undefined);
+                }
+            }
+        }
+
+        /** Create a bunch of fake Megolm sessions and stash them in the DB. */
+        function createMegolmSessions(store: CryptoStore, nDevices: number, nSessionsPerDevice: number) {
+            for (let i = 0; i < nDevices; i++) {
+                for (let j = 0; j < nSessionsPerDevice; j++) {
+                    store.storeEndToEndInboundGroupSession(
+                        pad43(`device${i}`),
+                        `session${j}`,
+                        {
+                            forwardingCurve25519KeyChain: [],
+                            keysClaimed: { ed25519: "sender_signing_key" },
+                            room_id: "!room:id",
+                            session: "sessionPickle",
+                        },
+                        undefined,
+                    );
+                }
+            }
+        }
+    });
 });

 describe("RustCrypto", () => {
@@ -142,7 +383,7 @@ describe("RustCrypto", () => {
        );
    });

-    describe(".importRoomKeys and .exportRoomKeys", () => {
+    describe("importing and exporting room keys", () => {
        let rustCrypto: RustCrypto;

        beforeEach(
@@ -158,7 +399,7 @@ describe("RustCrypto", () => {
            let importTotal = 0;
            const opt: ImportRoomKeysOpts = {
                progressCallback: (stage) => {
-                    importTotal = stage.total;
+                    importTotal = stage.total ?? 0;
                },
            };
            await rustCrypto.importRoomKeys(someRoomKeys, opt);
@@ -175,6 +416,29 @@ describe("RustCrypto", () => {

            expect(aSession).toStrictEqual(exportedKey);
        });
+
+        it("should import and export keys as JSON", async () => {
+            const someRoomKeys = testData.MEGOLM_SESSION_DATA_ARRAY;
+            let importTotal = 0;
+            const opt: ImportRoomKeysOpts = {
+                progressCallback: (stage) => {
+                    importTotal = stage.total ?? 0;
+                },
+            };
+            await rustCrypto.importRoomKeysAsJson(JSON.stringify(someRoomKeys), opt);
+
+            expect(importTotal).toBe(someRoomKeys.length);
+
+            const keys: Array<IMegolmSessionData> = JSON.parse(await rustCrypto.exportRoomKeysAsJson());
+            expect(Array.isArray(keys)).toBeTruthy();
+            expect(keys.length).toBe(someRoomKeys.length);
+
+            const aSession = someRoomKeys[0];
+
+            const exportedKey = keys.find((k) => k.session_id == aSession.session_id);
+
+            expect(aSession).toStrictEqual(exportedKey);
+        });
    });

    describe("call preprocess methods", () => {
@@ -294,6 +558,62 @@ describe("RustCrypto", () => {
        expect(mockCrossSigningIdentity.bootstrapCrossSigning).toHaveBeenCalledWith({});
    });

+    it("bootstrapSecretStorage creates new backup when requested", async () => {
+        const secretStorageCallbacks = {
+            getSecretStorageKey: async (keys: any, name: string) => {
+                return [[...Object.keys(keys.keys)][0], new Uint8Array(32)];
+            },
+        } as SecretStorageCallbacks;
+        const secretStorage = new ServerSideSecretStorageImpl(new DummyAccountDataClient(), secretStorageCallbacks);
+
+        const outgoingRequestProcessor = {
+            makeOutgoingRequest: jest.fn(),
+        } as unknown as Mocked<OutgoingRequestProcessor>;
+
+        const rustCrypto = await makeTestRustCrypto(
+            new MatrixHttpApi(new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>(), {
+                baseUrl: "http://server/",
+                prefix: "",
+                onlyData: true,
+            }),
+            testData.TEST_USER_ID,
+            undefined,
+            secretStorage,
+        );
+
+        rustCrypto["checkKeyBackupAndEnable"] = async () => {
+            return null;
+        };
+        (rustCrypto["crossSigningIdentity"] as any)["outgoingRequestProcessor"] = outgoingRequestProcessor;
+        const resetKeyBackup = (rustCrypto["resetKeyBackup"] = jest.fn());
+
+        async function createSecretStorageKey() {
+            return {
+                keyInfo: {} as AddSecretStorageKeyOpts,
+                privateKey: new Uint8Array(32),
+            };
+        }
+
+        // create initial secret storage
+        await rustCrypto.bootstrapCrossSigning({ setupNewCrossSigning: true });
+        await rustCrypto.bootstrapSecretStorage({
+            createSecretStorageKey,
+            setupNewSecretStorage: true,
+            setupNewKeyBackup: true,
+        });
+        // check that rustCrypto.resetKeyBackup was called
+        expect(resetKeyBackup.mock.calls).toHaveLength(1);
+
+        // reset secret storage
+        await rustCrypto.bootstrapSecretStorage({
+            createSecretStorageKey,
+            setupNewSecretStorage: true,
+            setupNewKeyBackup: true,
+        });
+        // check that rustCrypto.resetKeyBackup was called again
+        expect(resetKeyBackup.mock.calls).toHaveLength(2);
+    });
+
    it("isSecretStorageReady", async () => {
        const mockSecretStorage = {
            getDefaultKeyId: jest.fn().mockResolvedValue(null),
@@ -400,6 +720,58 @@ describe("RustCrypto", () => {
            await awaitCallToMakeOutgoingRequest();
            expect(olmMachine.outgoingRequests).toHaveBeenCalledTimes(2);
        });
+
+        it("should encode outgoing requests properly", async () => {
+            // we need a real OlmMachine, so replace the one created by beforeEach
+            rustCrypto = await makeTestRustCrypto();
+            const olmMachine: OlmMachine = rustCrypto["olmMachine"];
+
+            const outgoingRequestProcessor = {} as unknown as OutgoingRequestProcessor;
+            rustCrypto["outgoingRequestProcessor"] = outgoingRequestProcessor;
+            const outgoingRequestsManager = new OutgoingRequestsManager(logger, olmMachine, outgoingRequestProcessor);
+            rustCrypto["outgoingRequestsManager"] = outgoingRequestsManager;
+
+            // The second time we do a /keys/upload, the `device_keys` property
+            // should be absent from the request body
+            // cf. https://github.com/matrix-org/matrix-rust-sdk-crypto-wasm/issues/57
+            //
+            // On the first upload, we pretend that there are no OTKs, so it will
+            // try to upload more keys
+            let keysUploadCount = 0;
+            let deviceKeys: object;
+            let deviceKeysAbsent = false;
+            outgoingRequestProcessor.makeOutgoingRequest = jest.fn(async (request, uiaCallback?) => {
+                let resp: any = {};
+                if (request instanceof RustSdkCryptoJs.KeysUploadRequest) {
+                    if (keysUploadCount == 0) {
+                        deviceKeys = JSON.parse(request.body).device_keys;
+                        resp = { one_time_key_counts: { signed_curve25519: 0 } };
+                    } else {
+                        deviceKeysAbsent = !("device_keys" in JSON.parse(request.body));
+                        resp = { one_time_key_counts: { signed_curve25519: 50 } };
+                    }
+                    keysUploadCount++;
+                } else if (request instanceof RustSdkCryptoJs.KeysQueryRequest) {
+                    resp = {
+                        device_keys: {
+                            [TEST_USER]: {
+                                [TEST_DEVICE_ID]: deviceKeys,
+                            },
+                        },
+                    };
+                } else if (request instanceof RustSdkCryptoJs.UploadSigningKeysRequest) {
+                    // SigningKeysUploadRequest does not implement OutgoingRequest and does not need to be marked as sent.
+                    return;
+                }
+                if (request.id) {
+                    olmMachine.markRequestAsSent(request.id, request.type, JSON.stringify(resp));
+                }
+            });
+            await outgoingRequestsManager.doProcessOutgoingRequests();
+            await outgoingRequestsManager.doProcessOutgoingRequests();
+
+            expect(deviceKeysAbsent).toBe(true);
+        });
    });

    describe(".getEventEncryptionInfo", () => {
@@ -421,7 +793,7 @@ describe("RustCrypto", () => {
                decryptEvent: () =>
                    ({
                        senderCurve25519Key: "1234",
-                    } as IEventDecryptionResult),
+                    }) as IEventDecryptionResult,
            } as unknown as CryptoBackend;
            await event.attemptDecryption(mockCryptoBackend);

@@ -461,7 +833,7 @@ describe("RustCrypto", () => {
                decryptEvent: () =>
                    ({
                        clearEvent: { content: { body: "1234" } },
-                    } as unknown as IEventDecryptionResult),
+                    }) as unknown as IEventDecryptionResult,
            } as unknown as CryptoBackend;
            await encryptedEvent.attemptDecryption(mockCryptoBackend);
            return encryptedEvent;
@@ -739,8 +1111,8 @@ describe("RustCrypto", () => {
            // Expect the private key to be an Uint8Array with a length of 32
            expect(recoveryKey.privateKey).toBeInstanceOf(Uint8Array);
            expect(recoveryKey.privateKey.length).toBe(32);
-            // Expect keyInfo to be empty
-            expect(Object.keys(recoveryKey.keyInfo!).length).toBe(0);
+            // Expect passphrase info to be absent
+            expect(recoveryKey.keyInfo?.passphrase).toBeUndefined();
        });

        it("should create a recovery key with password", async () => {
@@ -758,13 +1130,9 @@ describe("RustCrypto", () => {
    });

    it("should wait for a keys/query before returning devices", async () => {
-        jest.useFakeTimers();
+        // We want to use fake timers, but the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
+        jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });

-        const mockHttpApi = new MatrixHttpApi(new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>(), {
-            baseUrl: "http://server/",
-            prefix: "",
-            onlyData: true,
-        });
        fetchMock.post("path:/_matrix/client/v3/keys/upload", { one_time_key_counts: {} });
        fetchMock.post("path:/_matrix/client/v3/keys/query", {
            device_keys: {
@@ -774,7 +1142,7 @@ describe("RustCrypto", () => {
            },
        });

-        const rustCrypto = await makeTestRustCrypto(mockHttpApi, testData.TEST_USER_ID);
+        const rustCrypto = await makeTestRustCrypto(makeMatrixHttpApi(), testData.TEST_USER_ID);

        // an attempt to fetch the device list should block
        const devicesPromise = rustCrypto.getUserDeviceInfo([testData.TEST_USER_ID]);
@@ -788,6 +1156,33 @@ describe("RustCrypto", () => {
        rustCrypto.stop();
    });

+    it("should emit events on device changes", async () => {
+        jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
+
+        fetchMock.post("path:/_matrix/client/v3/keys/upload", { one_time_key_counts: {} });
+        fetchMock.post("path:/_matrix/client/v3/keys/query", {
+            device_keys: {
+                [testData.TEST_USER_ID]: {
+                    [testData.TEST_DEVICE_ID]: testData.SIGNED_TEST_DEVICE_DATA,
+                },
+            },
+        });
+
+        const rustCrypto = await makeTestRustCrypto(makeMatrixHttpApi(), testData.TEST_USER_ID);
+        const willUpdateCallback = jest.fn();
+        rustCrypto.on(CryptoEvent.WillUpdateDevices, willUpdateCallback);
+        const devicesUpdatedCallback = jest.fn();
+        rustCrypto.on(CryptoEvent.DevicesUpdated, devicesUpdatedCallback);
+
+        rustCrypto.onSyncCompleted({});
+
+        // wait for the devices to be updated
+        await rustCrypto.getUserDeviceInfo([testData.TEST_USER_ID]);
+        expect(willUpdateCallback).toHaveBeenCalledWith([testData.TEST_USER_ID], false);
+        expect(devicesUpdatedCallback).toHaveBeenCalledWith([testData.TEST_USER_ID], false);
+        rustCrypto.stop();
+    });
+
    describe("requestDeviceVerification", () => {
        it("throws an error if the device is unknown", async () => {
            const rustCrypto = await makeTestRustCrypto();
@@ -900,12 +1295,6 @@ describe("RustCrypto", () => {
            // Return the key backup
            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);

-            const mockHttpApi = new MatrixHttpApi(new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>(), {
-                baseUrl: "http://server/",
-                prefix: "",
-                onlyData: true,
-            });
-
            const olmMachine = {
                getIdentity: jest.fn(),
                // Force the backup to be trusted by the olmMachine
@@ -918,7 +1307,7 @@ describe("RustCrypto", () => {
            const rustCrypto = new RustCrypto(
                logger,
                olmMachine,
-                mockHttpApi,
+                makeMatrixHttpApi(),
                testData.TEST_USER_ID,
                testData.TEST_DEVICE_ID,
                {} as ServerSideSecretStorage,
@@ -974,9 +1363,46 @@ describe("RustCrypto", () => {
                },
            });
        });
+
+        it("ignores invalid keys when restoring from backup", async () => {
+            const rustCrypto = await makeTestRustCrypto();
+            const olmMachine: OlmMachine = rustCrypto["olmMachine"];
+
+            await olmMachine.enableBackupV1(
+                (testData.SIGNED_BACKUP_DATA.auth_data as Curve25519AuthData).public_key,
+                testData.SIGNED_BACKUP_DATA.version!,
+            );
+
+            const backup = Array.from(testData.MEGOLM_SESSION_DATA_ARRAY);
+            // in addition to correct keys, we restore an invalid key
+            backup.push({ room_id: "!roomid", session_id: "sessionid" } as IMegolmSessionData);
+            const progressCallback = jest.fn();
+            await rustCrypto.importBackedUpRoomKeys(backup, { progressCallback });
+            expect(progressCallback).toHaveBeenCalledWith({
+                total: 3,
+                successes: 0,
+                stage: "load_keys",
+                failures: 1,
+            });
+            expect(progressCallback).toHaveBeenCalledWith({
+                total: 3,
+                successes: 1,
+                stage: "load_keys",
+                failures: 1,
+            });
+        });
    });
 });

+/** Build a MatrixHttpApi instance */
+function makeMatrixHttpApi(): MatrixHttpApi<IHttpOpts & { onlyData: true }> {
+    return new MatrixHttpApi(new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>(), {
+        baseUrl: "http://server/",
+        prefix: "",
+        onlyData: true,
+    });
+}
+
 /** build a basic RustCrypto instance for testing
 *
 * just provides default arguments for initRustCrypto()
@@ -988,5 +1414,54 @@ async function makeTestRustCrypto(
    secretStorage: ServerSideSecretStorage = {} as ServerSideSecretStorage,
    cryptoCallbacks: CryptoCallbacks = {} as CryptoCallbacks,
 ): Promise<RustCrypto> {
-    return await initRustCrypto(logger, http, userId, deviceId, secretStorage, cryptoCallbacks, null, undefined);
+    return await initRustCrypto({
+        logger,
+        http,
+        userId,
+        deviceId,
+        secretStorage,
+        cryptoCallbacks,
+        storePrefix: null,
+        storePassphrase: undefined,
+    });
+}
+
+/** emulate account data, storing in memory
+ */
+class DummyAccountDataClient
+    extends TypedEventEmitter<ClientEvent.AccountData, ClientEventHandlerMap>
+    implements AccountDataClient
+{
+    private storage: Map<string, any> = new Map();
+
+    public constructor() {
+        super();
+    }
+
+    public async getAccountDataFromServer<T extends Record<string, any>>(eventType: string): Promise<T | null> {
+        const ret = this.storage.get(eventType);
+
+        if (eventType) {
+            return ret as T;
+        } else {
+            return null;
+        }
+    }
+
+    public async setAccountData(eventType: string, content: any): Promise<{}> {
+        this.storage.set(eventType, content);
+        this.emit(
+            ClientEvent.AccountData,
+            new MatrixEvent({
+                content,
+                type: eventType,
+            }),
+        );
+        return {};
+    }
+}
+
+/** Pad a string to 43 characters long */
+function pad43(x: string): string {
+    return x + ".".repeat(43 - x.length);
 }
@@ -17,8 +17,19 @@ limitations under the License.
 import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-wasm";
 import { Mocked } from "jest-mock";

-import { isVerificationEvent, RustVerificationRequest } from "../../../src/rust-crypto/verification";
-import { OutgoingRequestProcessor } from "../../../src/rust-crypto/OutgoingRequestProcessor";
+import {
+    isVerificationEvent,
+    RustVerificationRequest,
+    verificationMethodIdentifierToMethod,
+} from "../../../src/rust-crypto/verification";
+import {
+    ShowSasCallbacks,
+    VerificationRequestEvent,
+    Verifier,
+    VerifierEvent,
+} from "../../../src/crypto-api/verification";
+import { OutgoingRequest, OutgoingRequestProcessor } from "../../../src/rust-crypto/OutgoingRequestProcessor";
+import { IDeviceKeys } from "../../../src/@types/crypto";
 import { EventType, MatrixEvent, MsgType } from "../../../src";

 describe("VerificationRequest", () => {
@@ -91,6 +102,354 @@ describe("VerificationRequest", () => {
            );
        });
    });
+
+    it("can verify with SAS", async () => {
+        const aliceUserId = "@alice:example.org";
+        const aliceDeviceId = "ABCDEFG";
+        const bobUserId = "@bob:example.org";
+        const bobDeviceId = "HIJKLMN";
+        const [aliceOlmMachine, aliceDeviceKeys, aliceCrossSigningKeys] = await initOlmMachineAndKeys(
+            aliceUserId,
+            aliceDeviceId,
+        );
+        const [bobOlmMachine, bobDeviceKeys, bobCrossSigningKeys] = await initOlmMachineAndKeys(bobUserId, bobDeviceId);
+
+        const aliceRequestLoop = makeRequestLoop(
+            aliceOlmMachine,
+            aliceDeviceKeys,
+            aliceCrossSigningKeys,
+            bobOlmMachine,
+            bobDeviceKeys,
+            bobCrossSigningKeys,
+        );
+        const bobRequestLoop = makeRequestLoop(
+            bobOlmMachine,
+            bobDeviceKeys,
+            bobCrossSigningKeys,
+            aliceOlmMachine,
+            aliceDeviceKeys,
+            aliceCrossSigningKeys,
+        );
+
+        try {
+            await aliceOlmMachine.updateTrackedUsers([new RustSdkCryptoJs.UserId(bobUserId)]);
+            await bobOlmMachine.updateTrackedUsers([new RustSdkCryptoJs.UserId(aliceUserId)]);
+
+            // Alice requests verification
+            const bobUserIdentity = await aliceOlmMachine.getIdentity(new RustSdkCryptoJs.UserId(bobUserId));
+
+            const roomId = new RustSdkCryptoJs.RoomId("!roomId:example.org");
+            const methods = [verificationMethodIdentifierToMethod("m.sas.v1")];
+            const innerVerificationRequest = await bobUserIdentity.requestVerification(
+                roomId,
+                new RustSdkCryptoJs.EventId("$m.key.verification.request"),
+                methods,
+            );
+            const aliceVerificationRequest = new RustVerificationRequest(
+                aliceOlmMachine,
+                innerVerificationRequest,
+                aliceRequestLoop as unknown as OutgoingRequestProcessor,
+                ["m.sas.v1"],
+            );
+
+            const verificationRequestContent = JSON.parse(await bobUserIdentity.verificationRequestContent(methods));
+            await bobOlmMachine.receiveVerificationEvent(
+                JSON.stringify({
+                    type: "m.room.message",
+                    sender: aliceUserId,
+                    event_id: "$m.key.verification.request",
+                    content: verificationRequestContent,
+                    origin_server_ts: Date.now(),
+                    unsigned: {
+                        age: 0,
+                    },
+                }),
+                roomId,
+            );
+
+            // Bob accepts
+            const bobInnerVerificationRequest = bobOlmMachine.getVerificationRequest(
+                new RustSdkCryptoJs.UserId(aliceUserId),
+                "$m.key.verification.request",
+            )!;
+            const bobVerificationRequest = new RustVerificationRequest(
+                bobOlmMachine,
+                bobInnerVerificationRequest,
+                bobRequestLoop as unknown as OutgoingRequestProcessor,
+                ["m.sas.v1"],
+            );
+
+            await bobVerificationRequest.accept();
+
+            // Alice starts the verification
+            const bobVerifierPromise: Promise<Verifier> = new Promise((resolve, reject) => {
+                bobVerificationRequest.on(VerificationRequestEvent.Change, () => {
+                    const verifier = bobVerificationRequest.verifier;
+                    if (verifier) {
+                        resolve(verifier);
+                    }
+                });
+            });
+            const aliceVerifier = await aliceVerificationRequest.startVerification("m.sas.v1");
+            const bobVerifier = await bobVerifierPromise;
+
+            // create a function to compare the SAS, and then let the verification run
+            let otherCallbacks: ShowSasCallbacks | undefined;
+            const compareSas = (callbacks: ShowSasCallbacks): void => {
+                if (otherCallbacks) {
+                    const ourDecimal = callbacks.sas.decimal!;
+                    const theirDecimal = otherCallbacks.sas.decimal!;
+                    if (ourDecimal.every((el, idx) => el == theirDecimal[idx])) {
+                        otherCallbacks.confirm();
+                        callbacks.confirm();
+                    } else {
+                        otherCallbacks.mismatch();
+                        callbacks.mismatch();
+                    }
+                } else {
+                    otherCallbacks = callbacks;
+                }
+            };
+            aliceVerifier.on(VerifierEvent.ShowSas, compareSas);
+            bobVerifier.on(VerifierEvent.ShowSas, compareSas);
+
+            await Promise.all([aliceVerifier.verify(), await bobVerifier.verify()]);
+        } finally {
+            await aliceRequestLoop.stop();
+            await bobRequestLoop.stop();
+        }
+    });
+
+    it("can handle simultaneous starts in SAS", async () => {
+        const aliceUserId = "@alice:example.org";
+        const aliceDeviceId = "ABCDEFG";
+        const bobUserId = "@bob:example.org";
+        const bobDeviceId = "HIJKLMN";
+        const [aliceOlmMachine, aliceDeviceKeys, aliceCrossSigningKeys] = await initOlmMachineAndKeys(
+            aliceUserId,
+            aliceDeviceId,
+        );
+        const [bobOlmMachine, bobDeviceKeys, bobCrossSigningKeys] = await initOlmMachineAndKeys(bobUserId, bobDeviceId);
+
+        let aliceStartRequest: RustSdkCryptoJs.RoomMessageRequest | undefined;
+        const aliceRequestLoop = makeRequestLoop(
+            aliceOlmMachine,
+            aliceDeviceKeys,
+            aliceCrossSigningKeys,
+            bobOlmMachine,
+            bobDeviceKeys,
+            bobCrossSigningKeys,
+            async (request): Promise<any> => {
+                // If the request is sending the m.key.verification.start
+                // event, we delay sending it until after Bob has also started
+                // a verification
+                if (
+                    !aliceStartRequest &&
+                    request instanceof RustSdkCryptoJs.RoomMessageRequest &&
+                    request.event_type == "m.key.verification.start"
+                ) {
+                    aliceStartRequest = request;
+                    return { event_id: "$m.key.verification.start" };
+                }
+            },
+        );
+        const bobRequestLoop = makeRequestLoop(
+            bobOlmMachine,
+            bobDeviceKeys,
+            bobCrossSigningKeys,
+            aliceOlmMachine,
+            aliceDeviceKeys,
+            aliceCrossSigningKeys,
+        );
+
+        try {
+            await aliceOlmMachine.updateTrackedUsers([new RustSdkCryptoJs.UserId(bobUserId)]);
+            await bobOlmMachine.updateTrackedUsers([new RustSdkCryptoJs.UserId(aliceUserId)]);
+
+            // Alice requests verification
+            const bobUserIdentity = await aliceOlmMachine.getIdentity(new RustSdkCryptoJs.UserId(bobUserId));
+
+            const roomId = new RustSdkCryptoJs.RoomId("!roomId:example.org");
+            const methods = [verificationMethodIdentifierToMethod("m.sas.v1")];
+            const innerVerificationRequest = await bobUserIdentity.requestVerification(
+                roomId,
+                new RustSdkCryptoJs.EventId("$m.key.verification.request"),
+                methods,
+            );
+            const aliceVerificationRequest = new RustVerificationRequest(
+                aliceOlmMachine,
+                innerVerificationRequest,
+                aliceRequestLoop as unknown as OutgoingRequestProcessor,
+                ["m.sas.v1"],
+            );
+
+            const verificationRequestContent = JSON.parse(await bobUserIdentity.verificationRequestContent(methods));
+            await bobOlmMachine.receiveVerificationEvent(
+                JSON.stringify({
+                    type: "m.room.message",
+                    sender: aliceUserId,
+                    event_id: "$m.key.verification.request",
+                    content: verificationRequestContent,
+                    origin_server_ts: Date.now(),
+                    unsigned: {
+                        age: 0,
+                    },
+                }),
+                roomId,
+            );
+
+            // Bob accepts
+            const bobInnerVerificationRequest = bobOlmMachine.getVerificationRequest(
+                new RustSdkCryptoJs.UserId(aliceUserId),
+                "$m.key.verification.request",
+            )!;
+            const bobVerificationRequest = new RustVerificationRequest(
+                bobOlmMachine,
+                bobInnerVerificationRequest,
+                bobRequestLoop as unknown as OutgoingRequestProcessor,
+                ["m.sas.v1"],
+            );
+
+            await bobVerificationRequest.accept();
+
+            // Alice and Bob both start the verification
+            const aliceVerifier = await aliceVerificationRequest.startVerification("m.sas.v1");
+            const bobVerifier = await bobVerificationRequest.startVerification("m.sas.v1");
+            // We can now send Alice's start message to Bob
+            await aliceRequestLoop.makeOutgoingRequest(aliceStartRequest!);
+
+            // create a function to compare the SAS, and then let the verification run
+            let otherCallbacks: ShowSasCallbacks | undefined;
+            const compareSas = (callbacks: ShowSasCallbacks) => {
+                if (otherCallbacks) {
+                    const ourDecimal = callbacks.sas.decimal!;
+                    const theirDecimal = otherCallbacks.sas.decimal!;
+                    if (ourDecimal.every((el, idx) => el == theirDecimal[idx])) {
+                        otherCallbacks.confirm();
+                        callbacks.confirm();
+                    } else {
+                        otherCallbacks.mismatch();
+                        callbacks.mismatch();
+                    }
+                } else {
+                    otherCallbacks = callbacks;
+                }
+            };
+            aliceVerifier.on(VerifierEvent.ShowSas, compareSas);
+            bobVerifier.on(VerifierEvent.ShowSas, compareSas);
+
+            await Promise.all([aliceVerifier.verify(), await bobVerifier.verify()]);
+        } finally {
+            await aliceRequestLoop.stop();
+            await bobRequestLoop.stop();
+        }
+    });
+
+    it("can verify by QR code", async () => {
+        const aliceUserId = "@alice:example.org";
+        const aliceDeviceId = "ABCDEFG";
+        const bobUserId = "@bob:example.org";
+        const bobDeviceId = "HIJKLMN";
+        const [aliceOlmMachine, aliceDeviceKeys, aliceCrossSigningKeys] = await initOlmMachineAndKeys(
+            aliceUserId,
+            aliceDeviceId,
+        );
+        const [bobOlmMachine, bobDeviceKeys, bobCrossSigningKeys] = await initOlmMachineAndKeys(bobUserId, bobDeviceId);
+
+        const aliceRequestLoop = makeRequestLoop(
+            aliceOlmMachine,
+            aliceDeviceKeys,
+            aliceCrossSigningKeys,
+            bobOlmMachine,
+            bobDeviceKeys,
+            bobCrossSigningKeys,
+        );
+        const bobRequestLoop = makeRequestLoop(
+            bobOlmMachine,
+            bobDeviceKeys,
+            bobCrossSigningKeys,
+            aliceOlmMachine,
+            aliceDeviceKeys,
+            aliceCrossSigningKeys,
+        );
+
+        try {
+            await aliceOlmMachine.updateTrackedUsers([new RustSdkCryptoJs.UserId(bobUserId)]);
+            await bobOlmMachine.updateTrackedUsers([new RustSdkCryptoJs.UserId(aliceUserId)]);
+
+            // Alice requests verification
+            const bobUserIdentity = await aliceOlmMachine.getIdentity(new RustSdkCryptoJs.UserId(bobUserId));
+
+            const roomId = new RustSdkCryptoJs.RoomId("!roomId:example.org");
+            const methods = [
+                verificationMethodIdentifierToMethod("m.reciprocate.v1"),
+                verificationMethodIdentifierToMethod("m.qr_code.show.v1"),
+            ];
+            const innerVerificationRequest = await bobUserIdentity.requestVerification(
+                roomId,
+                new RustSdkCryptoJs.EventId("$m.key.verification.request"),
+                methods,
+            );
+            const aliceVerificationRequest = new RustVerificationRequest(
+                aliceOlmMachine,
+                innerVerificationRequest,
+                aliceRequestLoop as unknown as OutgoingRequestProcessor,
+                ["m.reciprocate.v1", "m.qr_code.show.v1"],
+            );
+
+            const verificationRequestContent = JSON.parse(await bobUserIdentity.verificationRequestContent(methods));
+            await bobOlmMachine.receiveVerificationEvent(
+                JSON.stringify({
+                    type: "m.room.message",
+                    sender: aliceUserId,
+                    event_id: "$m.key.verification.request",
+                    content: verificationRequestContent,
+                    origin_server_ts: Date.now(),
+                    unsigned: {
+                        age: 0,
+                    },
+                }),
+                roomId,
+            );
+
+            // Bob accepts
+            const bobInnerVerificationRequest = bobOlmMachine.getVerificationRequest(
+                new RustSdkCryptoJs.UserId(aliceUserId),
+                "$m.key.verification.request",
+            )!;
+            const bobVerificationRequest = new RustVerificationRequest(
+                bobOlmMachine,
+                bobInnerVerificationRequest,
+                bobRequestLoop as unknown as OutgoingRequestProcessor,
+                ["m.reciprocate.v1", "m.qr_code.show.v1", "m.qr_code.scan.v1"],
+            );
+
+            await bobVerificationRequest.accept();
+
+            // Bob scans
+            const qrCode = await aliceVerificationRequest.generateQRCode();
+
+            const aliceVerifierPromise: Promise<Verifier> = new Promise((resolve, reject) => {
+                aliceVerificationRequest.on(VerificationRequestEvent.Change, () => {
+                    const verifier = aliceVerificationRequest.verifier;
+                    if (verifier) {
+                        resolve(verifier);
+                    }
+                });
+            });
+            const bobVerifier = await bobVerificationRequest.scanQRCode(qrCode!);
+
+            const aliceVerifier = await aliceVerifierPromise;
+            aliceVerifier.on(VerifierEvent.ShowReciprocateQr, (showQrCodeCallbacks) => {
+                showQrCodeCallbacks.confirm();
+            });
+
+            await Promise.all([aliceVerifier.verify(), await bobVerifier.verify()]);
+        } finally {
+            await aliceRequestLoop.stop();
+            await bobRequestLoop.stop();
+        }
+    });
 });

 describe("isVerificationEvent", () => {
@@ -152,3 +511,148 @@ function makeMockedInner(): Mocked<RustSdkCryptoJs.VerificationRequest> {
        },
    } as unknown as Mocked<RustSdkCryptoJs.VerificationRequest>;
 }
+
+interface CrossSigningKeys {
+    master_key: any;
+    self_signing_key: any;
+    user_signing_key: any;
+}
+
+/** create an Olm machine and device/cross-signing keys for a user */
+async function initOlmMachineAndKeys(
+    userId: string,
+    deviceId: string,
+): Promise<[RustSdkCryptoJs.OlmMachine, IDeviceKeys, CrossSigningKeys]> {
+    const olmMachine = await RustSdkCryptoJs.OlmMachine.initialize(
+        new RustSdkCryptoJs.UserId(userId),
+        new RustSdkCryptoJs.DeviceId(deviceId),
+        undefined,
+        undefined,
+    );
+    const { uploadKeysRequest, uploadSignaturesRequest, uploadSigningKeysRequest } =
+        await olmMachine.bootstrapCrossSigning(true);
+    const deviceKeys = JSON.parse(uploadKeysRequest.body).device_keys;
+    await olmMachine.markRequestAsSent(
+        uploadKeysRequest.id,
+        uploadKeysRequest.type,
+        '{"one_time_key_counts":{"signed_curve25519":100}}',
+    );
+    const crossSigningSignatures = JSON.parse(uploadSignaturesRequest.body);
+    for (const [keyId, signature] of Object.entries(crossSigningSignatures[userId][deviceId]["signatures"][userId])) {
+        deviceKeys["signatures"][userId][keyId] = signature;
+    }
+    const crossSigningKeys = JSON.parse(uploadSigningKeysRequest.body);
+    // note: the upload signatures request and upload signing keys requests
+    // don't need to be marked as sent in the Olm machine
+
+    return [olmMachine, deviceKeys, crossSigningKeys];
+}
+
+type CustomRequestHandler = (request: OutgoingRequest | RustSdkCryptoJs.UploadSigningKeysRequest) => Promise<any>;
+
+/** Loop for handling outgoing requests from an Olm machine.
+ *
+ * Simulates a server with two users: "us" and "them".  Handles key query
+ * requests, querying either our keys or the other user's keys.  Room messages
+ * are sent as incoming verification events to the other user.  A custom
+ * handler can be added to override default request processing (the handler
+ * should return a response body to inhibit default processing).
+ *
+ * Can also be used as an OutgoingRequestProcessor. */
+function makeRequestLoop(
+    ourOlmMachine: RustSdkCryptoJs.OlmMachine,
+    ourDeviceKeys: IDeviceKeys,
+    ourCrossSigningKeys: CrossSigningKeys,
+    theirOlmMachine: RustSdkCryptoJs.OlmMachine,
+    theirDeviceKeys: IDeviceKeys,
+    theirCrossSigningKeys: CrossSigningKeys,
+    customHandler?: CustomRequestHandler,
+) {
+    let stopRequestLoop = false;
+    const ourUserId = ourOlmMachine.userId.toString();
+    const ourDeviceId = ourOlmMachine.deviceId.toString();
+    const theirUserId = theirOlmMachine.userId.toString();
+    const theirDeviceId = theirOlmMachine.deviceId.toString();
+
+    function defaultHandler(request: OutgoingRequest | RustSdkCryptoJs.UploadSigningKeysRequest): any {
+        if (request instanceof RustSdkCryptoJs.KeysQueryRequest) {
+            const resp: Record<string, any> = {
+                device_keys: {},
+            };
+            const body = JSON.parse(request.body);
+            const query = body.device_keys;
+            const masterKeys: Record<string, any> = {};
+            const selfSigningKeys: Record<string, any> = {};
+            if (ourUserId in query) {
+                resp.device_keys[ourUserId] = { [ourDeviceId]: ourDeviceKeys };
+                masterKeys[ourUserId] = ourCrossSigningKeys.master_key;
+                selfSigningKeys[ourUserId] = ourCrossSigningKeys.self_signing_key;
+                resp.user_signing_keys = {
+                    [ourUserId]: ourCrossSigningKeys.user_signing_key,
+                };
+            }
+            if (theirUserId in query) {
+                resp.device_keys[theirUserId] = {
+                    [theirDeviceId]: theirDeviceKeys,
+                };
+                masterKeys[theirUserId] = theirCrossSigningKeys.master_key;
+                selfSigningKeys[theirUserId] = theirCrossSigningKeys.self_signing_key;
+            }
+            if (Object.keys(masterKeys).length) {
+                resp.master_keys = masterKeys;
+            }
+            if (Object.keys(selfSigningKeys).length) {
+                resp.self_signing_keys = selfSigningKeys;
+            }
+            return resp;
+        } else if (request instanceof RustSdkCryptoJs.RoomMessageRequest) {
+            theirOlmMachine.receiveVerificationEvent(
+                JSON.stringify({
+                    type: request.event_type,
+                    sender: ourUserId,
+                    event_id: "$" + request.event_type,
+                    content: JSON.parse(request.body),
+                    origin_server_ts: Date.now(),
+                    unsigned: {
+                        age: 0,
+                    },
+                }),
+                new RustSdkCryptoJs.RoomId(request.room_id),
+            );
+            return { event_id: "$" + request.event_type };
+        } else if (request instanceof RustSdkCryptoJs.SignatureUploadRequest) {
+            // this only gets called at the end after the verification
+            // succeeds, so we don't actually have to do anything.
+            return { failures: {} };
+        }
+        return {};
+    }
+
+    async function makeOutgoingRequest(
+        request: OutgoingRequest | RustSdkCryptoJs.UploadSigningKeysRequest,
+    ): Promise<any> {
+        const resp = (await customHandler?.(request)) ?? defaultHandler(request);
+        if (!(request instanceof RustSdkCryptoJs.UploadSigningKeysRequest) && request.id) {
+            await ourOlmMachine.markRequestAsSent(request.id!, request.type, JSON.stringify(resp));
+        }
+    }
+
+    async function runLoop() {
+        while (!stopRequestLoop) {
+            const requests = await ourOlmMachine.outgoingRequests();
+            for (const request of requests) {
+                await makeOutgoingRequest(request);
+            }
+        }
+    }
+
+    const loopCompletedPromise = runLoop();
+
+    return {
+        makeOutgoingRequest,
+        stop: async () => {
+            stopRequestLoop = true;
+            await loopCompletedPromise;
+        },
+    };
+}
@@ -33,7 +33,9 @@ describe("ServerSideSecretStorageImpl", function () {
        it("should allow storing a default key", async function () {
            const accountDataAdapter = mockAccountDataClient();
            const secretStorage = new ServerSideSecretStorageImpl(accountDataAdapter, {});
-            const result = await secretStorage.addKey("m.secret_storage.v1.aes-hmac-sha2");
+            const result = await secretStorage.addKey("m.secret_storage.v1.aes-hmac-sha2", {
+                key: new Uint8Array(32),
+            });

            // it should have made up a 32-character key id
            expect(result.keyId.length).toEqual(32);
@@ -46,7 +48,13 @@ describe("ServerSideSecretStorageImpl", function () {
        it("should allow storing a key with an explicit id", async function () {
            const accountDataAdapter = mockAccountDataClient();
            const secretStorage = new ServerSideSecretStorageImpl(accountDataAdapter, {});
-            const result = await secretStorage.addKey("m.secret_storage.v1.aes-hmac-sha2", {}, "myKeyId");
+            const result = await secretStorage.addKey(
+                "m.secret_storage.v1.aes-hmac-sha2",
+                {
+                    key: new Uint8Array(32),
+                },
+                "myKeyId",
+            );

            // it should have made up a 32-character key id
            expect(result.keyId).toEqual("myKeyId");
@@ -59,7 +67,10 @@ describe("ServerSideSecretStorageImpl", function () {
        it("should allow storing a key with a name", async function () {
            const accountDataAdapter = mockAccountDataClient();
            const secretStorage = new ServerSideSecretStorageImpl(accountDataAdapter, {});
-            const result = await secretStorage.addKey("m.secret_storage.v1.aes-hmac-sha2", { name: "mykey" });
+            const result = await secretStorage.addKey("m.secret_storage.v1.aes-hmac-sha2", {
+                name: "mykey",
+                key: new Uint8Array(32),
+            });

            expect(result.keyInfo.name).toEqual("mykey");

@@ -80,6 +91,7 @@ describe("ServerSideSecretStorageImpl", function () {
            };
            const result = await secretStorage.addKey("m.secret_storage.v1.aes-hmac-sha2", {
                passphrase,
+                key: new Uint8Array(32),
            });

            expect(result.keyInfo.passphrase).toEqual(passphrase);
@@ -93,7 +105,9 @@ describe("ServerSideSecretStorageImpl", function () {
        it("should complain about invalid algorithm", async function () {
            const accountDataAdapter = mockAccountDataClient();
            const secretStorage = new ServerSideSecretStorageImpl(accountDataAdapter, {});
-            await expect(() => secretStorage.addKey("bad_alg")).rejects.toThrow("Unknown key algorithm");
+            await expect(() => secretStorage.addKey("bad_alg", { key: new Uint8Array(32) })).rejects.toThrow(
+                "Unknown key algorithm",
+            );
        });
    });

@@ -0,0 +1,51 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { IEvent } from "../../src";
+import { randomString } from "../../src/randomstring";
+import { getRelationsThreadFilter } from "../../src/thread-utils";
+
+function makeEvent(relatesToEvent: string, relType: string): Partial<IEvent> {
+    return {
+        event_id: randomString(10),
+        type: "m.room.message",
+        content: {
+            "msgtype": "m.text",
+            "body": "foo",
+            "m.relates_to": {
+                rel_type: relType,
+                event_id: relatesToEvent,
+            },
+        },
+    };
+}
+
+describe("getRelationsThreadFilter", () => {
+    it("should filter out relations directly to the thread root event", () => {
+        const threadId = "thisIsMyThreadRoot";
+
+        const reactionToRoot = makeEvent(threadId, "m.annotation");
+        const editToRoot = makeEvent(threadId, "m.replace");
+        const firstThreadedReply = makeEvent(threadId, "m.thread");
+        const reactionToThreadedEvent = makeEvent(firstThreadedReply.event_id!, "m.annotation");
+
+        const filteredEvents = [reactionToRoot, editToRoot, firstThreadedReply, reactionToThreadedEvent].filter(
+            getRelationsThreadFilter(threadId),
+        );
+
+        expect(filteredEvents).toEqual([firstThreadedReply, reactionToThreadedEvent]);
+    });
+});
@@ -954,7 +954,7 @@ describe("Group Call", function () {
                            },
                        },
                    }),
-                } as MatrixEvent);
+                }) as MatrixEvent;

            it("should mute remote feed's audio after receiving metadata with video audio", async () => {
                const metadataEvent = getMetadataEvent(true, false);
@@ -965,7 +965,7 @@ describe("Group Call", function () {

                // @ts-ignore
                const call = groupCall.calls.get(FAKE_USER_ID_2)!.get(FAKE_DEVICE_ID_2)!;
-                call.getOpponentMember = () => ({ userId: call.invitee } as RoomMember);
+                call.getOpponentMember = () => ({ userId: call.invitee }) as RoomMember;
                // @ts-ignore Mock
                call.pushRemoteFeed(
                    // @ts-ignore Mock
@@ -992,7 +992,7 @@ describe("Group Call", function () {

                // @ts-ignore
                const call = groupCall.calls.get(FAKE_USER_ID_2).get(FAKE_DEVICE_ID_2)!;
-                call.getOpponentMember = () => ({ userId: call.invitee } as RoomMember);
+                call.getOpponentMember = () => ({ userId: call.invitee }) as RoomMember;
                // @ts-ignore Mock
                call.pushRemoteFeed(
                    // @ts-ignore Mock
@@ -1310,7 +1310,7 @@ describe("Group Call", function () {

            // @ts-ignore
            const call = groupCall.calls.get(FAKE_USER_ID_2)!.get(FAKE_DEVICE_ID_2)!;
-            call.getOpponentMember = () => ({ userId: call.invitee } as RoomMember);
+            call.getOpponentMember = () => ({ userId: call.invitee }) as RoomMember;
            call.onNegotiateReceived({
                getContent: () => ({
                    [SDPStreamMetadataKey]: {
@@ -0,0 +1,17 @@
+/*
+Copyright 2024 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+export type NonEmptyArray<T> = [T, ...T[]];
@@ -23,9 +23,8 @@ import { isProvided } from "../extensible_events_v1/utilities";
 /**
 * Represents the stable and unstable values of a given namespace.
 */
-export type TSNamespace<N> = N extends NamespacedValue<infer S, infer U>
-    ? TSNamespaceValue<S> | TSNamespaceValue<U>
-    : never;
+export type TSNamespace<N> =
+    N extends NamespacedValue<infer S, infer U> ? TSNamespaceValue<S> | TSNamespaceValue<U> : never;

 /**
 * Represents a namespaced value, if the value is a string. Used to extract provided types
@@ -26,7 +26,10 @@ export class NamespacedValue<S extends string, U extends string> {
    public constructor(stable: S, unstable: U);
    public constructor(stable: S, unstable?: U);
    public constructor(stable: null | undefined, unstable: U);
-    public constructor(public readonly stable?: S | null, public readonly unstable?: U) {
+    public constructor(
+        public readonly stable?: S | null,
+        public readonly unstable?: U,
+    ) {
        if (!this.unstable && !this.stable) {
            throw new Error("One of stable or unstable values must be supplied");
        }
@@ -15,20 +15,10 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import { SigningKey } from "oidc-client-ts";
-
-import { IClientWellKnown, IWellKnownConfig, IDelegatedAuthConfig, IServerVersions, M_AUTHENTICATION } from "./client";
+import { IClientWellKnown, IWellKnownConfig, IServerVersions } from "./client";
 import { logger } from "./logger";
 import { MatrixError, Method, timeoutSignal } from "./http-api";
-import { discoverAndValidateAuthenticationConfig } from "./oidc/discovery";
-import {
-    ValidatedIssuerConfig,
-    ValidatedIssuerMetadata,
-    validateOIDCIssuerWellKnown,
-    validateWellKnownAuthentication,
-} from "./oidc/validate";
-import { OidcError } from "./oidc/error";
-import { MINIMUM_MATRIX_VERSION } from "./version-support";
+import { SUPPORTED_MATRIX_VERSIONS } from "./version-support";

 // Dev note: Auto discovery is part of the spec.
 // See: https://matrix.org/docs/spec/client_server/r0.4.0.html#server-discovery
@@ -51,7 +41,10 @@ export enum AutoDiscoveryError {
    InvalidIs = "Invalid identity server discovery response",
    MissingWellknown = "No .well-known JSON file found",
    InvalidJson = "Invalid JSON",
-    HomeserverTooOld = "The homeserver does not meet the minimum version requirements",
+    UnsupportedHomeserverSpecVersion = "The homeserver does not meet the version requirements",
+
+    /** @deprecated Replaced by `UnsupportedHomeserverSpecVersion` */
+    HomeserverTooOld = UnsupportedHomeserverSpecVersion,
    // TODO: Implement when Sydent supports the `/versions` endpoint - https://github.com/matrix-org/sydent/issues/424
    //IdentityServerTooOld = "The identity server does not meet the minimum version requirements",
 }
@@ -62,26 +55,9 @@ interface AutoDiscoveryState {
 }
 interface WellKnownConfig extends Omit<IWellKnownConfig, "error">, AutoDiscoveryState {}

-/**
- * @deprecated in favour of OidcClientConfig
- */
-interface DelegatedAuthConfig extends IDelegatedAuthConfig, ValidatedIssuerConfig, AutoDiscoveryState {}
-
-/**
- * @experimental
- */
-export interface OidcClientConfig extends IDelegatedAuthConfig, ValidatedIssuerConfig {
-    metadata: ValidatedIssuerMetadata;
-    signingKeys?: SigningKey[];
-}
-
 export interface ClientConfig extends Omit<IClientWellKnown, "m.homeserver" | "m.identity_server"> {
    "m.homeserver": WellKnownConfig;
    "m.identity_server": WellKnownConfig;
-    /**
-     * @experimental
-     */
-    "m.authentication"?: (OidcClientConfig & AutoDiscoveryState) | AutoDiscoveryState;
 }

 /**
@@ -112,7 +88,11 @@ export class AutoDiscovery {

    public static readonly ERROR_INVALID_JSON = AutoDiscoveryError.InvalidJson;

-    public static readonly ERROR_HOMESERVER_TOO_OLD = AutoDiscoveryError.HomeserverTooOld;
+    public static readonly ERROR_UNSUPPORTED_HOMESERVER_SPEC_VERSION =
+        AutoDiscoveryError.UnsupportedHomeserverSpecVersion;
+
+    /** @deprecated Replaced by ERROR_UNSUPPORTED_HOMESERVER_SPEC_VERSION */
+    public static readonly ERROR_HOMESERVER_TOO_OLD = AutoDiscovery.ERROR_UNSUPPORTED_HOMESERVER_SPEC_VERSION;

    public static readonly ALL_ERRORS = Object.keys(AutoDiscoveryError) as AutoDiscoveryError[];

@@ -216,10 +196,19 @@ export class AutoDiscovery {
            return Promise.resolve(clientConfig);
        }

-        // Step 3.1: Non-spec check to ensure the server will actually work for us
-        if (!hsVersions.raw!["versions"].includes(MINIMUM_MATRIX_VERSION)) {
-            logger.error("Homeserver does not meet minimum version requirements");
-            clientConfig["m.homeserver"].error = AutoDiscovery.ERROR_HOMESERVER_TOO_OLD;
+        // Step 3.1: Non-spec check to ensure the server will actually work for us. We need to check if
+        // any of the versions in `SUPPORTED_MATRIX_VERSIONS` are listed in the /versions response.
+        const hsVersionSet = new Set(hsVersions.raw!["versions"]);
+        let supportedVersionFound = false;
+        for (const version of SUPPORTED_MATRIX_VERSIONS) {
+            if (hsVersionSet.has(version)) {
+                supportedVersionFound = true;
+                break;
+            }
+        }
+        if (!supportedVersionFound) {
+            logger.error("Homeserver does not meet version requirements");
+            clientConfig["m.homeserver"].error = AutoDiscovery.ERROR_UNSUPPORTED_HOMESERVER_SPEC_VERSION;

            // Supply the base_url to the caller because they may be ignoring liveliness
            // errors, like this one.
@@ -302,107 +291,10 @@ export class AutoDiscovery {
            }
        });

-        const authConfig = await this.discoverAndValidateAuthenticationConfig(wellknown);
-        clientConfig[M_AUTHENTICATION.stable!] = authConfig;
-
        // Step 8: Give the config to the caller (finally)
        return Promise.resolve(clientConfig);
    }

-    /**
-     * Validate delegated auth configuration
-     * @deprecated use discoverAndValidateAuthenticationConfig
-     * - m.authentication config is present and valid
-     * - delegated auth issuer openid-configuration is reachable
-     * - delegated auth issuer openid-configuration is configured correctly for us
-     * When successful, DelegatedAuthConfig will be returned with endpoints used for delegated auth
-     * Any errors are caught, and AutoDiscoveryState returned with error
-     * @param wellKnown - configuration object as returned
-     * by the .well-known auto-discovery endpoint
-     * @returns Config or failure result
-     */
-    public static async validateDiscoveryAuthenticationConfig(
-        wellKnown: IClientWellKnown,
-    ): Promise<DelegatedAuthConfig | AutoDiscoveryState> {
-        try {
-            const authentication = M_AUTHENTICATION.findIn<IDelegatedAuthConfig>(wellKnown) || undefined;
-            const homeserverAuthenticationConfig = validateWellKnownAuthentication(authentication);
-
-            const issuerOpenIdConfigUrl = `${this.sanitizeWellKnownUrl(
-                homeserverAuthenticationConfig.issuer,
-            )}/.well-known/openid-configuration`;
-            const issuerWellKnown = await this.fetchWellKnownObject<unknown>(issuerOpenIdConfigUrl);
-
-            if (issuerWellKnown.action !== AutoDiscoveryAction.SUCCESS) {
-                logger.error("Failed to fetch issuer openid configuration");
-                throw new Error(OidcError.General);
-            }
-
-            const validatedIssuerConfig = validateOIDCIssuerWellKnown(issuerWellKnown.raw);
-
-            const delegatedAuthConfig: DelegatedAuthConfig = {
-                state: AutoDiscoveryAction.SUCCESS,
-                error: null,
-                ...homeserverAuthenticationConfig,
-                ...validatedIssuerConfig,
-            };
-            return delegatedAuthConfig;
-        } catch (error) {
-            const errorMessage = (error as Error).message as unknown as OidcError;
-            const errorType = Object.values(OidcError).includes(errorMessage) ? errorMessage : OidcError.General;
-
-            const state =
-                errorType === OidcError.NotSupported ? AutoDiscoveryAction.IGNORE : AutoDiscoveryAction.FAIL_ERROR;
-
-            return {
-                state,
-                error: errorType,
-            };
-        }
-    }
-
-    /**
-     * Validate delegated auth configuration
-     * - m.authentication config is present and valid
-     * - delegated auth issuer openid-configuration is reachable
-     * - delegated auth issuer openid-configuration is configured correctly for us
-     * When successful, validated authentication metadata and optionally signing keys will be returned
-     * Any errors are caught, and AutoDiscoveryState returned with error
-     * @param wellKnown - configuration object as returned
-     * by the .well-known auto-discovery endpoint
-     * @returns Config or failure result
-     */
-    public static async discoverAndValidateAuthenticationConfig(
-        wellKnown: IClientWellKnown,
-    ): Promise<(OidcClientConfig & AutoDiscoveryState) | AutoDiscoveryState> {
-        try {
-            const authentication = M_AUTHENTICATION.findIn<IDelegatedAuthConfig>(wellKnown) || undefined;
-            const result = await discoverAndValidateAuthenticationConfig(authentication);
-
-            // include this for backwards compatibility
-            const validatedIssuerConfig = validateOIDCIssuerWellKnown(result.metadata);
-
-            const response = {
-                state: AutoDiscoveryAction.SUCCESS,
-                error: null,
-                ...validatedIssuerConfig,
-                ...result,
-            };
-            return response;
-        } catch (error) {
-            const errorMessage = (error as Error).message as unknown as OidcError;
-            const errorType = Object.values(OidcError).includes(errorMessage) ? errorMessage : OidcError.General;
-
-            const state =
-                errorType === OidcError.NotSupported ? AutoDiscoveryAction.IGNORE : AutoDiscoveryAction.FAIL_ERROR;
-
-            return {
-                state,
-                error: errorType,
-            };
-        }
-    }
-
    /**
     * Attempts to automatically discover client configuration information
     * prior to logging in. Such information includes the homeserver URL
@@ -209,7 +209,7 @@ import { IgnoredInvites } from "./models/invites-ignorer";
 import { UIARequest, UIAResponse } from "./@types/uia";
 import { LocalNotificationSettings } from "./@types/local_notifications";
 import { buildFeatureSupportMap, Feature, ServerSupport } from "./feature";
-import { CryptoBackend } from "./common-crypto/CryptoBackend";
+import { BackupDecryptor, CryptoBackend } from "./common-crypto/CryptoBackend";
 import { RUST_SDK_STORE_PREFIX } from "./rust-crypto/constants";
 import { BootstrapCrossSigningOpts, CrossSigningKeyInfo, CryptoApi, ImportRoomKeysOpts } from "./crypto-api";
 import { DeviceInfoMap } from "./crypto/DeviceList";
@@ -221,6 +221,7 @@ import {
 } from "./secret-storage";
 import { RegisterRequest, RegisterResponse } from "./@types/registration";
 import { MatrixRTCSessionManager } from "./matrixrtc/MatrixRTCSessionManager";
+import { getRelationsThreadFilter } from "./thread-utils";

 export type Store = IStore;

@@ -624,13 +625,10 @@ export interface IServerVersions {
    unstable_features: Record<string, boolean>;
 }

-export const M_AUTHENTICATION = new UnstableValue("m.authentication", "org.matrix.msc2965.authentication");
-
 export interface IClientWellKnown {
    [key: string]: any;
    "m.homeserver"?: IWellKnownConfig;
    "m.identity_server"?: IWellKnownConfig;
-    [M_AUTHENTICATION.name]?: IDelegatedAuthConfig; // MSC2965
 }

 export interface IWellKnownConfig<T = IClientWellKnown> {
@@ -644,14 +642,6 @@ export interface IWellKnownConfig<T = IClientWellKnown> {
    server_name?: string;
 }

-export interface IDelegatedAuthConfig {
-    // MSC2965
-    /** The OIDC Provider/issuer the client should use */
-    issuer: string;
-    /** The optional URL of the web UI where the user can manage their account */
-    account?: string;
-}
-
 interface IKeyBackupPath {
    path: string;
    queryData?: {
@@ -961,7 +951,8 @@ type CryptoEvents =
    | CryptoEvent.KeysChanged
    | CryptoEvent.Warning
    | CryptoEvent.DevicesUpdated
-    | CryptoEvent.WillUpdateDevices;
+    | CryptoEvent.WillUpdateDevices
+    | CryptoEvent.LegacyCryptoStoreMigrationProgress;

 type MatrixEventEvents = MatrixEventEvent.Decrypted | MatrixEventEvent.Replaced | MatrixEventEvent.VisibilityChange;

@@ -1303,7 +1294,13 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
    protected txnCtr = 0;
    protected mediaHandler = new MediaHandler(this);
    protected sessionId: string;
-    protected pendingEventEncryption = new Map<string, Promise<void>>();
+
+    /** IDs of events which are currently being encrypted.
+     *
+     * This is part of the cancellation mechanism: if the event is no longer listed here when encryption completes,
+     * that tells us that it has been cancelled, and we should not send it.
+     */
+    private eventsBeingEncrypted = new Set<string>();

    private useE2eForGroupCall = true;
    private toDeviceMessageQueue: ToDeviceMessageQueue;
@@ -1443,7 +1440,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
        // correctly handle notification counts on encrypted rooms.
        // This fixes https://github.com/vector-im/element-web/issues/9421
        this.on(RoomEvent.Receipt, (event, room) => {
-            if (room && this.isRoomEncrypted(room.roomId)) {
+            if (room?.hasEncryptionStateEvent()) {
                // Figure out if we've read something or if it's just informational
                const content = event.getContent();
                const isSelf =
@@ -2315,17 +2312,25 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa

        // importing rust-crypto will download the webassembly, so we delay it until we know it will be
        // needed.
+        this.logger.debug("Downloading Rust crypto library");
        const RustCrypto = await import("./rust-crypto");
-        const rustCrypto = await RustCrypto.initRustCrypto(
-            this.logger,
-            this.http,
-            userId,
-            deviceId,
-            this.secretStorage,
-            this.cryptoCallbacks,
-            useIndexedDB ? RUST_SDK_STORE_PREFIX : null,
-            this.pickleKey,
-        );
+
+        const rustCrypto = await RustCrypto.initRustCrypto({
+            logger: this.logger,
+            http: this.http,
+            userId: userId,
+            deviceId: deviceId,
+            secretStorage: this.secretStorage,
+            cryptoCallbacks: this.cryptoCallbacks,
+            storePrefix: useIndexedDB ? RUST_SDK_STORE_PREFIX : null,
+            storePassphrase: this.pickleKey,
+            legacyCryptoStore: this.cryptoStore,
+            legacyPickleKey: this.pickleKey ?? "DEFAULT_KEY",
+            legacyMigrationProgressListener: (progress, total) => {
+                this.emit(CryptoEvent.LegacyCryptoStoreMigrationProgress, progress, total);
+            },
+        });
+
        rustCrypto.setSupportedVerificationMethods(this.verificationMethods);

        this.cryptoBackend = rustCrypto;
@@ -2344,6 +2349,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
            CryptoEvent.KeyBackupSessionsRemaining,
            CryptoEvent.KeyBackupFailed,
            CryptoEvent.KeyBackupDecryptionKeyCached,
+            CryptoEvent.KeysChanged,
+            CryptoEvent.DevicesUpdated,
+            CryptoEvent.WillUpdateDevices,
        ]);
    }

@@ -3235,6 +3243,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     * @param roomId - The room ID to enable encryption in.
     * @param config - The encryption config for the room.
     * @returns A promise that will resolve when encryption is set up.
+     *
+     * @deprecated Not supported for Rust Cryptography. To enable encryption in a room, send an `m.room.encryption`
+     * state event.
     */
    public setRoomEncryption(roomId: string, config: IRoomEncryption): Promise<void> {
        if (!this.crypto) {
@@ -3247,6 +3258,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     * Whether encryption is enabled for a room.
     * @param roomId - the room id to query.
     * @returns whether encryption is enabled.
+     *
+     * @deprecated Not correctly supported for Rust Cryptography. Use {@link CryptoApi.isEncryptionEnabledInRoom} and/or
+     *    {@link Room.hasEncryptionStateEvent}.
     */
    public isRoomEncrypted(roomId: string): boolean {
        const room = this.getRoom(roomId);
@@ -3258,8 +3272,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa

        // if there is an 'm.room.encryption' event in this room, it should be
        // encrypted (independently of whether we actually support encryption)
-        const ev = room.currentState.getStateEvents(EventType.RoomEncryption, "");
-        if (ev) {
+        if (room.hasEncryptionStateEvent()) {
            return true;
        }

@@ -3895,7 +3908,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
        }

        let totalKeyCount = 0;
-        let keys: IMegolmSessionData[] = [];
+        let totalFailures = 0;
+        let totalImported = 0;

        const path = this.makeKeyBackupPath(targetRoomId, targetSessionId, backupInfo.version);

@@ -3931,25 +3945,61 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                { prefix: ClientPrefix.V3 },
            );

-            if ((res as IRoomsKeysResponse).rooms) {
-                const rooms = (res as IRoomsKeysResponse).rooms;
-                for (const [roomId, roomData] of Object.entries(rooms)) {
-                    if (!roomData.sessions) continue;
+            // We have finished fetching the backup, go to next step
+            if (progressCallback) {
+                progressCallback({
+                    stage: "load_keys",
+                });
+            }

-                    totalKeyCount += Object.keys(roomData.sessions).length;
-                    const roomKeys = await backupDecryptor.decryptSessions(roomData.sessions);
-                    for (const k of roomKeys) {
-                        k.room_id = roomId;
-                        keys.push(k);
-                    }
-                }
+            if ((res as IRoomsKeysResponse).rooms) {
+                // We have a full backup here, it can get quite big, so we need to decrypt and import it in chunks.
+
+                // Get the total count as a first pass
+                totalKeyCount = this.getTotalKeyCount(res as IRoomsKeysResponse);
+                // Now decrypt and import the keys in chunks
+                await this.handleDecryptionOfAFullBackup(
+                    res as IRoomsKeysResponse,
+                    backupDecryptor,
+                    200,
+                    async (chunk) => {
+                        // We have a chunk of decrypted keys: import them
+                        try {
+                            await this.cryptoBackend!.importBackedUpRoomKeys(chunk, {
+                                untrusted,
+                            });
+                            totalImported += chunk.length;
+                        } catch (e) {
+                            totalFailures += chunk.length;
+                            // We failed to import some keys, but we should still try to import the rest?
+                            // Log the error and continue
+                            logger.error("Error importing keys from backup", e);
+                        }
+
+                        if (progressCallback) {
+                            progressCallback({
+                                total: totalKeyCount,
+                                successes: totalImported,
+                                stage: "load_keys",
+                                failures: totalFailures,
+                            });
+                        }
+                    },
+                );
            } else if ((res as IRoomKeysResponse).sessions) {
+                // For now we don't chunk for a single room backup, but we could in the future.
+                // Currently it is not used by the application.
                const sessions = (res as IRoomKeysResponse).sessions;
                totalKeyCount = Object.keys(sessions).length;
-                keys = await backupDecryptor.decryptSessions(sessions);
+                const keys = await backupDecryptor.decryptSessions(sessions);
                for (const k of keys) {
                    k.room_id = targetRoomId!;
                }
+                await this.cryptoBackend.importBackedUpRoomKeys(keys, {
+                    progressCallback,
+                    untrusted,
+                });
+                totalImported = keys.length;
            } else {
                totalKeyCount = 1;
                try {
@@ -3958,7 +4008,12 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                    });
                    key.room_id = targetRoomId!;
                    key.session_id = targetSessionId!;
-                    keys.push(key);
+
+                    await this.cryptoBackend.importBackedUpRoomKeys([key], {
+                        progressCallback,
+                        untrusted,
+                    });
+                    totalImported = 1;
                } catch (e) {
                    this.logger.debug("Failed to decrypt megolm session from backup", e);
                }
@@ -3967,15 +4022,88 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
            backupDecryptor.free();
        }

-        await this.cryptoBackend.importBackedUpRoomKeys(keys, {
-            progressCallback,
-            untrusted,
-        });
-
        /// in case entering the passphrase would add a new signature?
        await this.cryptoBackend.checkKeyBackupAndEnable();

-        return { total: totalKeyCount, imported: keys.length };
+        return { total: totalKeyCount, imported: totalImported };
+    }
+
+    /**
+     * This method calculates the total number of keys present in the response of a `/room_keys/keys` call.
+     *
+     * @param res - The response from the server containing the keys to be counted.
+     *
+     * @returns The total number of keys in the backup.
+     */
+    private getTotalKeyCount(res: IRoomsKeysResponse): number {
+        const rooms = res.rooms;
+        let totalKeyCount = 0;
+        for (const roomData of Object.values(rooms)) {
+            if (!roomData.sessions) continue;
+            totalKeyCount += Object.keys(roomData.sessions).length;
+        }
+        return totalKeyCount;
+    }
+
+    /**
+     * This method handles the decryption of a full backup, i.e a call to `/room_keys/keys`.
+     * It will decrypt the keys in chunks and call the `block` callback for each chunk.
+     *
+     * @param res - The response from the server containing the keys to be decrypted.
+     * @param backupDecryptor - An instance of the BackupDecryptor class used to decrypt the keys.
+     * @param chunkSize - The size of the chunks to be processed at a time.
+     * @param block - A callback function that is called for each chunk of keys.
+     *
+     * @returns A promise that resolves when the decryption is complete.
+     */
+    private async handleDecryptionOfAFullBackup(
+        res: IRoomsKeysResponse,
+        backupDecryptor: BackupDecryptor,
+        chunkSize: number,
+        block: (chunk: IMegolmSessionData[]) => Promise<void>,
+    ): Promise<void> {
+        const rooms = (res as IRoomsKeysResponse).rooms;
+
+        let groupChunkCount = 0;
+        let chunkGroupByRoom: Map<string, IKeyBackupRoomSessions> = new Map();
+
+        const handleChunkCallback = async (roomChunks: Map<string, IKeyBackupRoomSessions>): Promise<void> => {
+            const currentChunk: IMegolmSessionData[] = [];
+            for (const roomId of roomChunks.keys()) {
+                const decryptedSessions = await backupDecryptor.decryptSessions(roomChunks.get(roomId)!);
+                for (const sessionId in decryptedSessions) {
+                    const k = decryptedSessions[sessionId];
+                    k.room_id = roomId;
+                    currentChunk.push(k);
+                }
+            }
+            await block(currentChunk);
+        };
+
+        for (const [roomId, roomData] of Object.entries(rooms)) {
+            if (!roomData.sessions) continue;
+
+            chunkGroupByRoom.set(roomId, {});
+
+            for (const [sessionId, session] of Object.entries(roomData.sessions)) {
+                const sessionsForRoom = chunkGroupByRoom.get(roomId)!;
+                sessionsForRoom[sessionId] = session;
+                groupChunkCount += 1;
+                if (groupChunkCount >= chunkSize) {
+                    // We have enough chunks to decrypt
+                    await handleChunkCallback(chunkGroupByRoom);
+                    chunkGroupByRoom = new Map();
+                    // There might be remaining keys for that room, so add back an entry for the current room.
+                    chunkGroupByRoom.set(roomId, {});
+                    groupChunkCount = 0;
+                }
+            }
+        }
+
+        // Handle remaining chunk if needed
+        if (groupChunkCount > 0) {
+            await handleChunkCallback(chunkGroupByRoom);
+        }
    }

    public deleteKeysFromBackup(roomId: undefined, sessionId: undefined, version?: string): Promise<void>;
@@ -4324,9 +4452,10 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
            throw new Error("cannot cancel an event with status " + event.status);
        }

-        // if the event is currently being encrypted then
+        // If the event is currently being encrypted then remove it from the pending list, to indicate that it should
+        // not be sent.
        if (event.status === EventStatus.ENCRYPTING) {
-            this.pendingEventEncryption.delete(event.getId()!);
+            this.eventsBeingEncrypted.delete(event.getId()!);
        } else if (this.scheduler && event.status === EventStatus.QUEUED) {
            // tell the scheduler to forget about it, if it's queued
            this.scheduler.removeEventFromQueue(event);
@@ -4625,96 +4754,102 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     * encrypts the event if necessary; adds the event to the queue, or sends it; marks the event as sent/unsent
     * @returns returns a promise which resolves with the result of the send request
     */
-    protected encryptAndSendEvent(room: Room | null, event: MatrixEvent): Promise<ISendEventResponse> {
-        let cancelled = false;
-        // Add an extra Promise.resolve() to turn synchronous exceptions into promise rejections,
-        // so that we can handle synchronous and asynchronous exceptions with the
-        // same code path.
-        return Promise.resolve()
-            .then(() => {
-                const encryptionPromise = this.encryptEventIfNeeded(event, room ?? undefined);
-                if (!encryptionPromise) return null; // doesn't need encryption
+    protected async encryptAndSendEvent(room: Room | null, event: MatrixEvent): Promise<ISendEventResponse> {
+        try {
+            let cancelled: boolean;
+            this.eventsBeingEncrypted.add(event.getId()!);
+            try {
+                await this.encryptEventIfNeeded(event, room ?? undefined);
+            } finally {
+                cancelled = !this.eventsBeingEncrypted.delete(event.getId()!);
+            }

-                this.pendingEventEncryption.set(event.getId()!, encryptionPromise);
-                this.updatePendingEventStatus(room, event, EventStatus.ENCRYPTING);
-                return encryptionPromise.then(() => {
-                    if (!this.pendingEventEncryption.has(event.getId()!)) {
-                        // cancelled via MatrixClient::cancelPendingEvent
-                        cancelled = true;
-                        return;
-                    }
-                    this.updatePendingEventStatus(room, event, EventStatus.SENDING);
-                });
-            })
-            .then(() => {
-                if (cancelled) return {} as ISendEventResponse;
-                let promise: Promise<ISendEventResponse> | null = null;
-                if (this.scheduler) {
-                    // if this returns a promise then the scheduler has control now and will
-                    // resolve/reject when it is done. Internally, the scheduler will invoke
-                    // processFn which is set to this._sendEventHttpRequest so the same code
-                    // path is executed regardless.
-                    promise = this.scheduler.queueEvent(event);
-                    if (promise && this.scheduler.getQueueForEvent(event)!.length > 1) {
-                        // event is processed FIFO so if the length is 2 or more we know
-                        // this event is stuck behind an earlier event.
-                        this.updatePendingEventStatus(room, event, EventStatus.QUEUED);
-                    }
-                }
+            if (cancelled) {
+                // cancelled via MatrixClient::cancelPendingEvent
+                return {} as ISendEventResponse;
+            }

-                if (!promise) {
-                    promise = this.sendEventHttpRequest(event);
-                    if (room) {
-                        promise = promise.then((res) => {
-                            room.updatePendingEvent(event, EventStatus.SENT, res["event_id"]);
-                            return res;
-                        });
-                    }
-                }
+            // encryptEventIfNeeded may have updated the status from SENDING to ENCRYPTING. If so, we need
+            // to put it back.
+            if (event.status === EventStatus.ENCRYPTING) {
+                this.updatePendingEventStatus(room, event, EventStatus.SENDING);
+            }

-                return promise;
-            })
-            .catch((err) => {
-                this.logger.error("Error sending event", err.stack || err);
-                try {
-                    // set the error on the event before we update the status:
-                    // updating the status emits the event, so the state should be
-                    // consistent at that point.
-                    event.error = err;
-                    this.updatePendingEventStatus(room, event, EventStatus.NOT_SENT);
-                } catch (e) {
-                    this.logger.error("Exception in error handler!", (<Error>e).stack || err);
+            let promise: Promise<ISendEventResponse> | null = null;
+            if (this.scheduler) {
+                // if this returns a promise then the scheduler has control now and will
+                // resolve/reject when it is done. Internally, the scheduler will invoke
+                // processFn which is set to this._sendEventHttpRequest so the same code
+                // path is executed regardless.
+                promise = this.scheduler.queueEvent(event);
+                if (promise && this.scheduler.getQueueForEvent(event)!.length > 1) {
+                    // event is processed FIFO so if the length is 2 or more we know
+                    // this event is stuck behind an earlier event.
+                    this.updatePendingEventStatus(room, event, EventStatus.QUEUED);
                }
-                if (err instanceof MatrixError) {
-                    err.event = event;
+            }
+
+            if (!promise) {
+                promise = this.sendEventHttpRequest(event);
+                if (room) {
+                    promise = promise.then((res) => {
+                        room.updatePendingEvent(event, EventStatus.SENT, res["event_id"]);
+                        return res;
+                    });
                }
-                throw err;
-            });
+            }
+
+            return await promise;
+        } catch (err) {
+            this.logger.error("Error sending event", err);
+            try {
+                // set the error on the event before we update the status:
+                // updating the status emits the event, so the state should be
+                // consistent at that point.
+                event.error = <MatrixError>err;
+                this.updatePendingEventStatus(room, event, EventStatus.NOT_SENT);
+            } catch (e) {
+                this.logger.error("Exception in error handler!", e);
+            }
+            if (err instanceof MatrixError) {
+                err.event = event;
+            }
+            throw err;
+        }
    }

-    private encryptEventIfNeeded(event: MatrixEvent, room?: Room): Promise<void> | null {
+    private async encryptEventIfNeeded(event: MatrixEvent, room?: Room): Promise<void> {
+        // If the room is unknown, we cannot encrypt for it
+        if (!room) return;
+
+        if (!(await this.shouldEncryptEventForRoom(event, room))) return;
+
+        if (!this.cryptoBackend && this.usingExternalCrypto) {
+            // The client has opted to allow sending messages to encrypted
+            // rooms even if the room is encrypted, and we haven't set up
+            // crypto. This is useful for users of matrix-org/pantalaimon
+            return;
+        }
+
+        if (!this.cryptoBackend) {
+            throw new Error("This room is configured to use encryption, but your client does not support encryption.");
+        }
+
+        this.updatePendingEventStatus(room, event, EventStatus.ENCRYPTING);
+        await this.cryptoBackend.encryptEvent(event, room);
+    }
+
+    /**
+     * Determine whether a given event should be encrypted when we send it to the given room.
+     *
+     * This takes into account event type and room configuration.
+     */
+    private async shouldEncryptEventForRoom(event: MatrixEvent, room: Room): Promise<boolean> {
        if (event.isEncrypted()) {
            // this event has already been encrypted; this happens if the
            // encryption step succeeded, but the send step failed on the first
            // attempt.
-            return null;
-        }
-
-        if (event.isRedaction()) {
-            // Redactions do not support encryption in the spec at this time,
-            // whilst it mostly worked in some clients, it wasn't compliant.
-            return null;
-        }
-
-        if (!room || !this.isRoomEncrypted(event.getRoomId()!)) {
-            return null;
-        }
-
-        if (!this.cryptoBackend && this.usingExternalCrypto) {
-            // The client has opted to allow sending messages to encrypted
-            // rooms even if the room is encrypted, and we haven't setup
-            // crypto. This is useful for users of matrix-org/pantalaimon
-            return null;
+            return false;
        }

        if (event.getType() === EventType.Reaction) {
@@ -4728,14 +4863,23 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
            // The reaction key / content / emoji value does warrant encrypting, but
            // this will be handled separately by encrypting just this value.
            // See https://github.com/matrix-org/matrix-doc/pull/1849#pullrequestreview-248763642
-            return null;
+            return false;
        }

-        if (!this.cryptoBackend) {
-            throw new Error("This room is configured to use encryption, but your client does not support encryption.");
+        if (event.isRedaction()) {
+            // Redactions do not support encryption in the spec at this time.
+            // Whilst it mostly worked in some clients, it wasn't compliant.
+            return false;
        }

-        return this.cryptoBackend.encryptEvent(event, room);
+        // If the room has an m.room.encryption event, we should encrypt.
+        if (room.hasEncryptionStateEvent()) return true;
+
+        // If we have a crypto impl, and *it* thinks we should encrypt, then we should.
+        if (await this.cryptoBackend?.isEncryptionEnabledInRoom(room.roomId)) return true;
+
+        // Otherwise, no need to encrypt.
+        return false;
    }

    /**
@@ -4750,7 +4894,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
        eventType?: EventType | string | null,
    ): EventType | string | null | undefined {
        if (eventType === EventType.Reaction) return eventType;
-        return this.isRoomEncrypted(roomId) ? EventType.RoomMessageEncrypted : eventType;
+        return this.getRoom(roomId)?.hasEncryptionStateEvent() ? EventType.RoomMessageEncrypted : eventType;
    }

    protected updatePendingEventStatus(room: Room | null, event: MatrixEvent, newStatus: EventStatus): void {
@@ -5680,6 +5824,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     * @param allowDirectLinks - If true, return any non-mxc URLs
     * directly. Fetching such URLs will leak information about the user to
     * anyone they share a room with. If false, will return null for such URLs.
+     * @param allowRedirects - If true, the caller supports the URL being 307 or
+     * 308 redirected to another resource upon request. If false, redirects
+     * are not expected.
     * @returns the avatar URL or null.
     */
    public mxcUrlToHttp(
@@ -5688,8 +5835,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
        height?: number,
        resizeMethod?: string,
        allowDirectLinks?: boolean,
+        allowRedirects?: boolean,
    ): string | null {
-        return getHttpUriForMxc(this.baseUrl, mxcUrl, width, height, resizeMethod, allowDirectLinks);
+        return getHttpUriForMxc(this.baseUrl, mxcUrl, width, height, resizeMethod, allowDirectLinks, allowRedirects);
    }

    /**
@@ -5968,14 +6116,14 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                const resOlder: IRelationsResponse = await this.fetchRelations(
                    timelineSet.room.roomId,
                    thread.id,
-                    THREAD_RELATION_TYPE.name,
+                    null,
                    null,
                    { dir: Direction.Backward, from: res.start, recurse: recurse || undefined },
                );
                const resNewer: IRelationsResponse = await this.fetchRelations(
                    timelineSet.room.roomId,
                    thread.id,
-                    THREAD_RELATION_TYPE.name,
+                    null,
                    null,
                    { dir: Direction.Forward, from: res.end, recurse: recurse || undefined },
                );
@@ -5983,10 +6131,11 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                    // Order events from most recent to oldest (reverse-chronological).
                    // We start with the last event, since that's the point at which we have known state.
                    // events_after is already backwards; events_before is forwards.
-                    ...resNewer.chunk.reverse().map(mapper),
+                    ...resNewer.chunk.reverse().filter(getRelationsThreadFilter(thread.id)).map(mapper),
                    event,
-                    ...resOlder.chunk.map(mapper),
+                    ...resOlder.chunk.filter(getRelationsThreadFilter(thread.id)).map(mapper),
                ];
+
                for (const event of events) {
                    await timelineSet.thread?.processEvent(event);
                }
@@ -6361,6 +6510,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                        const stateEvents = res.state.filter(noUnsafeEventProps).map(this.getEventMapper());
                        roomState.setUnknownStateEvents(stateEvents);
                    }
+
                    const token = res.end;
                    const matrixEvents = res.chunk.filter(noUnsafeEventProps).map(this.getEventMapper());

@@ -6388,7 +6538,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
            }

            const recurse = this.canSupport.get(Feature.RelationsRecursion) !== ServerSupport.Unsupported;
-            promise = this.fetchRelations(eventTimeline.getRoomId() ?? "", thread.id, THREAD_RELATION_TYPE.name, null, {
+            promise = this.fetchRelations(eventTimeline.getRoomId() ?? "", thread.id, null, null, {
                dir,
                limit: opts.limit,
                from: token ?? undefined,
@@ -6396,7 +6546,10 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
            })
                .then(async (res) => {
                    const mapper = this.getEventMapper();
-                    const matrixEvents = res.chunk.filter(noUnsafeEventProps).map(mapper);
+                    const matrixEvents = res.chunk
+                        .filter(noUnsafeEventProps)
+                        .filter(getRelationsThreadFilter(thread.id))
+                        .map(mapper);

                    // Process latest events first
                    for (const event of matrixEvents.slice().reverse()) {
@@ -7444,16 +7597,11 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
            return this.serverVersionsPromise;
        }

+        // We send an authenticated request as of MSC4026
        this.serverVersionsPromise = this.http
-            .request<IServerVersions>(
-                Method.Get,
-                "/_matrix/client/versions",
-                undefined, // queryParams
-                undefined, // data
-                {
-                    prefix: "",
-                },
-            )
+            .authedRequest<IServerVersions>(Method.Get, "/_matrix/client/versions", undefined, undefined, {
+                prefix: "",
+            })
            .catch((e) => {
                // Need to unset this if it fails, otherwise we'll never retry
                this.serverVersionsPromise = undefined;
@@ -7591,7 +7739,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
    public async relations(
        roomId: string,
        eventId: string,
-        relationType?: RelationType | string | null,
+        relationType: RelationType | string | null,
        eventType?: EventType | string | null,
        opts: IRelationsRequestOpts = { dir: Direction.Backward },
    ): Promise<{
@@ -7726,6 +7874,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     */
    public setAccessToken(token: string): void {
        this.http.opts.accessToken = token;
+        // The /versions response can vary for different users so clear the cache
+        this.serverVersionsPromise = undefined;
    }

    /**
@@ -8114,7 +8264,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
    public fetchRelations(
        roomId: string,
        eventId: string,
-        relationType?: RelationType | string | null,
+        relationType: RelationType | string | null,
        eventType?: EventType | string | null,
        opts: IRelationsRequestOpts = { dir: Direction.Backward },
    ): Promise<IRelationsResponse> {
@@ -9813,6 +9963,20 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
            throw err;
        }
    }
+
+    /**
+     * Get the OIDC issuer responsible for authentication on this server, if any
+     * @returns Resolves: A promise of an object containing the OIDC issuer if configured
+     * @returns Rejects: when the request fails (module:http-api.MatrixError)
+     * @experimental - part of MSC2965
+     */
+    public async getAuthIssuer(): Promise<{
+        issuer: string;
+    }> {
+        return this.http.request(Method.Get, "/auth_issuer", undefined, undefined, {
+            prefix: ClientPrefix.Unstable + "/org.matrix.msc2965",
+        });
+    }
 }

 /**
@@ -28,6 +28,9 @@ import { encodeParams } from "./utils";
 * directly. Fetching such URLs will leak information about the user to
 * anyone they share a room with. If false, will return the emptry string
 * for such URLs.
+ * @param allowRedirects - If true, the caller supports the URL being 307 or
+ * 308 redirected to another resource upon request. If false, redirects
+ * are not expected.
 * @returns The complete URL to the content.
 */
 export function getHttpUriForMxc(
@@ -37,6 +40,7 @@ export function getHttpUriForMxc(
    height?: number,
    resizeMethod?: string,
    allowDirectLinks = false,
+    allowRedirects?: boolean,
 ): string {
    if (typeof mxc !== "string" || !mxc) {
        return "";
@@ -67,6 +71,11 @@ export function getHttpUriForMxc(
        prefix = "/_matrix/media/v3/thumbnail/";
    }

+    if (typeof allowRedirects === "boolean") {
+        // We add this after, so we don't convert everything to a thumbnail request.
+        params["allow_redirect"] = JSON.stringify(allowRedirects);
+    }
+
    const fragmentOffset = serverAndMediaId.indexOf("#");
    let fragment = "";
    if (fragmentOffset >= 0) {
@@ -18,7 +18,7 @@ import type { IMegolmSessionData } from "./@types/crypto";
 import { Room } from "./models/room";
 import { DeviceMap } from "./models/device";
 import { UIAuthCallback } from "./interactive-auth";
-import { AddSecretStorageKeyOpts, SecretStorageCallbacks, SecretStorageKeyDescription } from "./secret-storage";
+import { PassphraseInfo, SecretStorageCallbacks, SecretStorageKeyDescription } from "./secret-storage";
 import { VerificationRequest } from "./crypto-api/verification";
 import { BackupTrustInfo, KeyBackupCheck, KeyBackupInfo } from "./crypto-api/keybackup";
 import { ISignatures } from "./@types/signed";
@@ -53,6 +53,18 @@ export interface CryptoApi {
     */
    getOwnDeviceKeys(): Promise<OwnDeviceKeys>;

+    /**
+     * Check if we believe the given room to be encrypted.
+     *
+     * This method returns true if the room has been configured with encryption. The setting is persistent, so that
+     * even if the encryption event is removed from the room state, it still returns true. This helps to guard against
+     * a downgrade attack wherein a server admin attempts to remove encryption.
+     *
+     * @returns `true` if the room with the supplied ID is encrypted. `false` if the room is not encrypted, or is unknown to
+     * us.
+     */
+    isEncryptionEnabledInRoom(roomId: string): Promise<boolean>;
+
    /**
     * Perform any background tasks that can be done before a message is ready to
     * send, in order to speed up sending of the message.
@@ -84,6 +96,17 @@ export interface CryptoApi {
     */
    exportRoomKeys(): Promise<IMegolmSessionData[]>;

+    /**
+     * Get a JSON list containing all of the room keys
+     *
+     * This should be encrypted before returning it to the user.
+     *
+     * @returns a promise which resolves to a JSON string
+     *    encoding a list of session export objects,
+     *    each of which is an IMegolmSessionData
+     */
+    exportRoomKeysAsJson(): Promise<string>;
+
    /**
     * Import a list of room keys previously exported by exportRoomKeys
     *
@@ -93,6 +116,17 @@ export interface CryptoApi {
     */
    importRoomKeys(keys: IMegolmSessionData[], opts?: ImportRoomKeysOpts): Promise<void>;

+    /**
+     * Import a JSON string encoding a list of room keys previously
+     * exported by exportRoomKeysAsJson
+     *
+     * @param keys - a JSON string encoding a list of session export
+     *    objects, each of which is an IMegolmSessionData
+     * @param opts - options object
+     * @returns a promise which resolves once the keys have been imported
+     */
+    importRoomKeysAsJson(keys: string, opts?: ImportRoomKeysOpts): Promise<void>;
+
    /**
     * Check if the given user has published cross-signing keys.
     *
@@ -189,7 +223,7 @@ export interface CryptoApi {
     * Cross-signing a device indicates, to our other devices and to other users, that we have verified that it really
     * belongs to us.
     *
-     * Requires that cross-signing has been set up on this device (normally by calling {@link bootstrapCrossSigning}.
+     * Requires that cross-signing has been set up on this device (normally by calling {@link bootstrapCrossSigning}).
     *
     * *Note*: Do not call this unless you have verified, somehow, that the device is genuine!
     *
@@ -581,18 +615,20 @@ export class DeviceVerificationStatus {

 /**
 * Room key import progress report.
- * Used when calling {@link CryptoApi#importRoomKeys} as the parameter of
+ * Used when calling {@link CryptoApi#importRoomKeys} or
+ * {@link CryptoApi#importRoomKeysAsJson} as the parameter of
 * the progressCallback. Used to display feedback.
 */
 export interface ImportRoomKeyProgressData {
    stage: string; // TODO: Enum
-    successes: number;
-    failures: number;
-    total: number;
+    successes?: number;
+    failures?: number;
+    total?: number;
 }

 /**
- * Options object for {@link CryptoApi#importRoomKeys}.
+ * Options object for {@link CryptoApi#importRoomKeys} and
+ * {@link CryptoApi#importRoomKeysAsJson}.
 */
 export interface ImportRoomKeysOpts {
    /** Reports ongoing progress of the import process. Can be used for feedback. */
@@ -710,10 +746,15 @@ export interface CrossSigningKeyInfo {
 }

 /**
- * Recovery key created by {@link CryptoApi#createRecoveryKeyFromPassphrase}
+ * Recovery key created by {@link CryptoApi#createRecoveryKeyFromPassphrase} or {@link CreateSecretStorageOpts#createSecretStorageKey}.
 */
 export interface GeneratedSecretStorageKey {
-    keyInfo?: AddSecretStorageKeyOpts;
+    keyInfo?: {
+        /** If the key was derived from a passphrase, information (algorithm, salt, etc) on that derivation. */
+        passphrase?: PassphraseInfo;
+        /** Optional human-readable name for the key, to be stored in account_data. */
+        name?: string;
+    };
    /** The raw generated private key. */
    privateKey: Uint8Array;
    /** The generated key, encoded for display to the user per https://spec.matrix.org/v1.7/client-server-api/#key-representation. */
@@ -64,7 +64,7 @@ export interface InboundGroupSessionData {
    room_id: string; // eslint-disable-line camelcase
    /** pickled Olm.InboundGroupSession */
    session: string;
-    keysClaimed: Record<string, string>;
+    keysClaimed?: Record<string, string>;
    /** Devices involved in forwarding this session to us (normally empty). */
    forwardingCurve25519KeyChain: string[];
    /** whether this session is untrusted. */
@@ -38,7 +38,10 @@ interface ISecretRequestInternal {
 export class SecretSharing {
    private requests = new Map<string, ISecretRequestInternal>();

-    public constructor(private readonly baseApis: MatrixClient, private readonly cryptoCallbacks: ICryptoCallbacks) {}
+    public constructor(
+        private readonly baseApis: MatrixClient,
+        private readonly cryptoCallbacks: ICryptoCallbacks,
+    ) {}

    /**
     * Request a secret from another device
@@ -73,11 +73,7 @@ export class SecretStorage<B extends MatrixClient | undefined = MatrixClient> im
    /**
     * Add a key for encrypting secrets.
     */
-    public addKey(
-        algorithm: string,
-        opts: AddSecretStorageKeyOpts = {},
-        keyId?: string,
-    ): Promise<SecretStorageKeyObject> {
+    public addKey(algorithm: string, opts: AddSecretStorageKeyOpts, keyId?: string): Promise<SecretStorageKeyObject> {
        return this.storageImpl.addKey(algorithm, opts, keyId);
    }

@@ -210,7 +210,11 @@ export abstract class DecryptionAlgorithm {
 export class DecryptionError extends Error {
    public readonly detailedString: string;

-    public constructor(public readonly code: string, msg: string, details?: Record<string, string | Error>) {
+    public constructor(
+        public readonly code: string,
+        msg: string,
+        details?: Record<string, string | Error>,
+    ) {
        super(msg);
        this.code = code;
        this.name = "DecryptionError";
@@ -242,7 +246,11 @@ export class UnknownDeviceError extends Error {
     * @param msg - message describing the problem
     * @param devices - set of unknown devices per user we're warning about
     */
-    public constructor(msg: string, public readonly devices: DeviceInfoMap, public event?: MatrixEvent) {
+    public constructor(
+        msg: string,
+        public readonly devices: DeviceInfoMap,
+        public event?: MatrixEvent,
+    ) {
        super(msg);
        this.name = "UnknownDeviceError";
        this.devices = devices;
@@ -164,7 +164,10 @@ class OutboundSessionInfo {
     * @param sharedHistory - whether the session can be freely shared with
     *    other group members, according to the room history visibility settings
     */
-    public constructor(public readonly sessionId: string, public readonly sharedHistory = false) {
+    public constructor(
+        public readonly sessionId: string,
+        public readonly sharedHistory = false,
+    ) {
        this.creationTime = new Date().getTime();
    }

@@ -124,7 +124,10 @@ export class BackupManager {
    // The backup manager will schedule backup of keys when active (`scheduleKeyBackupSend`), this allows cancel when client is stopped
    private clientRunning = true;

-    public constructor(private readonly baseApis: MatrixClient, public readonly getKey: GetKey) {
+    public constructor(
+        private readonly baseApis: MatrixClient,
+        public readonly getKey: GetKey,
+    ) {
        this.checkedForBackup = false;
        this.sendingBackups = false;
    }
@@ -773,7 +776,10 @@ const UNSTABLE_MSC3270_NAME = new UnstableValue(
 export class Aes256 implements BackupAlgorithm {
    public static algorithmName = UNSTABLE_MSC3270_NAME.name;

-    public constructor(public readonly authData: IAes256AuthData, private readonly key: Uint8Array) {}
+    public constructor(
+        public readonly authData: IAes256AuthData,
+        private readonly key: Uint8Array,
+    ) {}

    public static async init(authData: IAes256AuthData, getKey: () => Promise<Uint8Array>): Promise<Aes256> {
        if (!authData) {
@@ -259,6 +259,15 @@ export enum CryptoEvent {
    WillUpdateDevices = "crypto.willUpdateDevices",
    DevicesUpdated = "crypto.devicesUpdated",
    KeysChanged = "crossSigning.keysChanged",
+
+    /**
+     * Fires when data is being migrated from legacy crypto to rust crypto.
+     *
+     * The payload is a pair `(progress, total)`, where `progress` is the number of steps completed so far, and
+     * `total` is the total number of steps. When migration is complete, a final instance of the event is emitted, with
+     * `progress === total === -1`.
+     */
+    LegacyCryptoStoreMigrationProgress = "crypto.legacyCryptoStoreMigrationProgress",
 }

 export type CryptoEventHandlerMap = {
@@ -368,6 +377,8 @@ export type CryptoEventHandlerMap = {
     */
    [CryptoEvent.DevicesUpdated]: (users: string[], initialFetch: boolean) => void;
    [CryptoEvent.UserCrossSigningUpdated]: (userId: string) => void;
+
+    [CryptoEvent.LegacyCryptoStoreMigrationProgress]: (progress: number, total: number) => void;
 };

 export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap> implements CryptoBackend {
@@ -708,25 +719,30 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
    public async createRecoveryKeyFromPassphrase(password?: string): Promise<IRecoveryKey> {
        const decryption = new global.Olm.PkDecryption();
        try {
-            const keyInfo: Partial<IRecoveryKey["keyInfo"]> = {};
            if (password) {
                const derivation = await keyFromPassphrase(password);
-                keyInfo.passphrase = {
-                    algorithm: "m.pbkdf2",
-                    iterations: derivation.iterations,
-                    salt: derivation.salt,
+
+                decryption.init_with_private_key(derivation.key);
+                const privateKey = decryption.get_private_key();
+                return {
+                    keyInfo: {
+                        passphrase: {
+                            algorithm: "m.pbkdf2",
+                            iterations: derivation.iterations,
+                            salt: derivation.salt,
+                        },
+                    },
+                    privateKey: privateKey,
+                    encodedPrivateKey: encodeRecoveryKey(privateKey),
                };
-                keyInfo.pubkey = decryption.init_with_private_key(derivation.key);
            } else {
-                keyInfo.pubkey = decryption.generate_key();
+                decryption.generate_key();
+                const privateKey = decryption.get_private_key();
+                return {
+                    privateKey: privateKey,
+                    encodedPrivateKey: encodeRecoveryKey(privateKey),
+                };
            }
-            const privateKey = decryption.get_private_key();
-            const encodedPrivateKey = encodeRecoveryKey(privateKey);
-            return {
-                keyInfo: keyInfo as IRecoveryKey["keyInfo"],
-                encodedPrivateKey,
-                privateKey,
-            };
        } finally {
            decryption?.free();
        }
@@ -968,7 +984,7 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
     */
    // TODO this does not resolve with what it says it does
    public async bootstrapSecretStorage({
-        createSecretStorageKey = async (): Promise<IRecoveryKey> => ({} as IRecoveryKey),
+        createSecretStorageKey = async (): Promise<IRecoveryKey> => ({}) as IRecoveryKey,
        keyBackupInfo,
        setupNewKeyBackup,
        setupNewSecretStorage,
@@ -986,17 +1002,11 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
        let newKeyId: string | null = null;

        // create a new SSSS key and set it as default
-        const createSSSS = async (opts: AddSecretStorageKeyOpts, privateKey?: Uint8Array): Promise<string> => {
-            if (privateKey) {
-                opts.key = privateKey;
-            }
-
+        const createSSSS = async (opts: AddSecretStorageKeyOpts): Promise<string> => {
            const { keyId, keyInfo } = await secretStorage.addKey(SECRET_STORAGE_ALGORITHM_V1_AES, opts);

-            if (privateKey) {
-                // make the private key available to encrypt 4S secrets
-                builder.ssssCryptoCallbacks.addPrivateKey(keyId, keyInfo, privateKey);
-            }
+            // make the private key available to encrypt 4S secrets
+            builder.ssssCryptoCallbacks.addPrivateKey(keyId, keyInfo, opts.key);

            await secretStorage.setDefaultKeyId(keyId);
            return keyId;
@@ -1060,8 +1070,8 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
            // secrets using it, in theory. We could move them to the new key but a)
            // that would mean we'd need to prompt for the old passphrase, and b)
            // it's not clear that would be the right thing to do anyway.
-            const { keyInfo = {} as AddSecretStorageKeyOpts, privateKey } = await createSecretStorageKey();
-            newKeyId = await createSSSS(keyInfo, privateKey);
+            const { keyInfo, privateKey } = await createSecretStorageKey();
+            newKeyId = await createSSSS({ passphrase: keyInfo?.passphrase, key: privateKey, name: keyInfo?.name });
        } else if (!storageExists && keyBackupInfo) {
            // we have an existing backup, but no SSSS
            logger.log("Secret storage does not exist, using key backup key");
@@ -1071,7 +1081,7 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
            const backupKey = (await this.getSessionBackupPrivateKey()) || (await getKeyBackupPassphrase?.());

            // create a new SSSS key and use the backup key as the new SSSS key
-            const opts = {} as AddSecretStorageKeyOpts;
+            const opts = { key: backupKey } as AddSecretStorageKeyOpts;

            if (keyBackupInfo.auth_data.private_key_salt && keyBackupInfo.auth_data.private_key_iterations) {
                // FIXME: ???
@@ -1083,7 +1093,7 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
                };
            }

-            newKeyId = await createSSSS(opts, backupKey);
+            newKeyId = await createSSSS(opts);

            // store the backup key in secret storage
            await secretStorage.store("m.megolm_backup.v1", encodeBase64(backupKey!), [newKeyId]);
@@ -2244,10 +2254,13 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
        const res = await this.baseApis.uploadKeysRequest(requestBody);

        if (fallbackJson) {
-            this.fallbackCleanup = setTimeout(() => {
-                delete this.fallbackCleanup;
-                this.olmDevice.forgetOldFallbackKey();
-            }, 60 * 60 * 1000);
+            this.fallbackCleanup = setTimeout(
+                () => {
+                    delete this.fallbackCleanup;
+                    this.olmDevice.forgetOldFallbackKey();
+                },
+                60 * 60 * 1000,
+            );
        }

        await this.olmDevice.markKeysAsPublished();
@@ -3129,6 +3142,16 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
        return exportedSessions;
    }

+    /**
+     * Get a JSON list containing all of the room keys
+     *
+     * @returns a JSON string encoding a list of session
+     *    export objects, each of which is an IMegolmSessionData
+     */
+    public async exportRoomKeysAsJson(): Promise<string> {
+        return JSON.stringify(await this.exportRoomKeys());
+    }
+
    /**
     * Import a list of room keys previously exported by exportRoomKeys
     *
@@ -3171,6 +3194,19 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
        ).then();
    }

+    /**
+     * Import a JSON string encoding a list of room keys previously
+     * exported by exportRoomKeysAsJson
+     *
+     * @param keys - a JSON string encoding a list of session export
+     *    objects, each of which is an IMegolmSessionData
+     * @param opts - options object
+     * @returns a promise which resolves once the keys have been imported
+     */
+    public async importRoomKeysAsJson(keys: string, opts?: ImportRoomKeysOpts): Promise<void> {
+        return await this.importRoomKeys(JSON.parse(keys));
+    }
+
    /**
     * Counts the number of end to end session keys that are waiting to be backed up
     * @returns Promise which resolves to the number of sessions requiring backup
@@ -4260,6 +4296,13 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
        return this.roomList.isRoomEncrypted(roomId);
    }

+    /**
+     * Implementation of {@link CryptoApi#isEncryptionEnabledInRoom}.
+     */
+    public async isEncryptionEnabledInRoom(roomId: string): Promise<boolean> {
+        return this.isRoomEncrypted(roomId);
+    }
+
    /**
     * @returns information about the encryption on the room with the supplied
     * ID, or null if the room is not encrypted or unknown to us.
@@ -15,6 +15,8 @@ limitations under the License.
 */

 // Export for backward compatibility
+import { ImportRoomKeyProgressData } from "../crypto-api";
+
 export type {
    Curve25519AuthData as ICurve25519AuthData,
    Aes256AuthData as IAes256AuthData,
@@ -41,5 +43,5 @@ export interface IKeyBackupRestoreResult {

 export interface IKeyBackupRestoreOpts {
    cacheCompleteCallback?: () => void;
-    progressCallback?: (progress: { stage: string }) => void;
+    progressCallback?: (progress: ImportRoomKeyProgressData) => void;
 }
@@ -46,8 +46,41 @@ export interface SecretStorePrivateKeys {
 * Abstraction of things that can store data required for end-to-end encryption
 */
 export interface CryptoStore {
+    /**
+     * Returns true if this CryptoStore has ever been initialised (ie, it might contain data).
+     *
+     * Unlike the rest of the methods in this interface, can be called before {@link CryptoStore#startup}.
+     *
+     * @internal
+     */
+    containsData(): Promise<boolean>;
+
+    /**
+     * Initialise this crypto store.
+     *
+     * Typically, this involves provisioning storage, and migrating any existing data to the current version of the
+     * storage schema where appropriate.
+     *
+     * Must be called before any of the rest of the methods in this interface.
+     */
    startup(): Promise<CryptoStore>;
+
    deleteAllData(): Promise<void>;
+
+    /**
+     * Get data on how much of the libolm to Rust Crypto migration has been done.
+     *
+     * @internal
+     */
+    getMigrationState(): Promise<MigrationState>;
+
+    /**
+     * Set data on how much of the libolm to Rust Crypto migration has been done.
+     *
+     * @internal
+     */
+    setMigrationState(migrationState: MigrationState): Promise<void>;
+
    getOrAddOutgoingRoomKeyRequest(request: OutgoingRoomKeyRequest): Promise<OutgoingRoomKeyRequest>;
    getOutgoingRoomKeyRequest(requestBody: IRoomKeyRequestBody): Promise<OutgoingRoomKeyRequest | null>;
    getOutgoingRoomKeyRequestByState(wantedStates: number[]): Promise<OutgoingRoomKeyRequest | null>;
@@ -99,6 +132,23 @@ export interface CryptoStore {
    getEndToEndSessionProblem(deviceKey: string, timestamp: number): Promise<IProblem | null>;
    filterOutNotifiedErrorDevices(devices: IOlmDevice[]): Promise<IOlmDevice[]>;

+    /**
+     * Get a batch of end-to-end sessions from the database.
+     *
+     * @returns A batch of Olm Sessions, or `null` if no sessions are left.
+     * @internal
+     */
+    getEndToEndSessionsBatch(): Promise<ISessionInfo[] | null>;
+
+    /**
+     * Delete a batch of end-to-end sessions from the database.
+     *
+     * Any sessions in the list which are not found are silently ignored.
+     *
+     * @internal
+     */
+    deleteEndToEndSessionsBatch(sessions: { deviceKey?: string; sessionId?: string }[]): Promise<void>;
+
    // Inbound Group Sessions
    getEndToEndInboundGroupSession(
        senderCurve25519Key: string,
@@ -126,6 +176,30 @@ export interface CryptoStore {
        txn: unknown,
    ): void;

+    /**
+     * Count the number of Megolm sessions in the database.
+     *
+     * @internal
+     */
+    countEndToEndInboundGroupSessions(): Promise<number>;
+
+    /**
+     * Get a batch of Megolm sessions from the database.
+     *
+     * @returns A batch of Megolm Sessions, or `null` if no sessions are left.
+     * @internal
+     */
+    getEndToEndInboundGroupSessionsBatch(): Promise<SessionExtended[] | null>;
+
+    /**
+     * Delete a batch of Megolm sessions from the database.
+     *
+     * Any sessions in the list which are not found are silently ignored.
+     *
+     * @internal
+     */
+    deleteEndToEndInboundGroupSessionsBatch(sessions: { senderKey: string; sessionId: string }[]): Promise<void>;
+
    // Device Data
    getEndToEndDeviceData(txn: unknown, func: (deviceData: IDeviceData | null) => void): void;
    storeEndToEndDeviceData(deviceData: IDeviceData, txn: unknown): void;
@@ -149,12 +223,19 @@ export interface CryptoStore {

 export type Mode = "readonly" | "readwrite";

+/** Data on a Megolm session */
 export interface ISession {
    senderKey: string;
    sessionId: string;
    sessionData?: InboundGroupSessionData;
 }

+/** Extended data on a Megolm session */
+export interface SessionExtended extends ISession {
+    needsBackup: boolean;
+}
+
+/** Data on an Olm session */
 export interface ISessionInfo {
    deviceKey?: string;
    sessionId?: string;
@@ -224,3 +305,44 @@ export interface ParkedSharedHistory {
    keysClaimed: ReturnType<MatrixEvent["getKeysClaimed"]>; // XXX: Less type dependence on MatrixEvent
    forwardingCurve25519KeyChain: string[];
 }
+
+/**
+ * Keys for the `account` object store to store the migration state.
+ * Values are defined in `MigrationState`.
+ * @internal
+ */
+export const ACCOUNT_OBJECT_KEY_MIGRATION_STATE = "migrationState";
+
+/**
+ * A record of which steps have been completed in the libolm to Rust Crypto migration.
+ *
+ * Used by {@link CryptoStore#getMigrationState} and {@link CryptoStore#setMigrationState}.
+ *
+ * @internal
+ */
+export enum MigrationState {
+    /** No migration steps have yet been completed. */
+    NOT_STARTED,
+
+    /** We have migrated the account data, cross-signing keys, etc. */
+    INITIAL_DATA_MIGRATED,
+
+    /** INITIAL_DATA_MIGRATED, and in addition, we have migrated all the Olm sessions. */
+    OLM_SESSIONS_MIGRATED,
+
+    /** OLM_SESSIONS_MIGRATED, and in addition, we have migrated all the Megolm sessions. */
+    MEGOLM_SESSIONS_MIGRATED,
+
+    /** MEGOLM_SESSIONS_MIGRATED, and in addition, we have migrated all the room settings. */
+    ROOM_SETTINGS_MIGRATED,
+
+    /** ROOM_SETTINGS_MIGRATED, and in addition, we have done the first own keys query in order to
+     * load the public part of the keys that have been migrated */
+    INITIAL_OWN_KEY_QUERY_DONE,
+}
+
+/**
+ * The size of batches to be returned by {@link CryptoStore#getEndToEndSessionsBatch} and
+ * {@link CryptoStore#getEndToEndInboundGroupSessionsBatch}.
+ */
+export const SESSION_BATCH_SIZE = 50;
@@ -21,18 +21,23 @@ import {
    IDeviceData,
    IProblem,
    ISession,
+    SessionExtended,
    ISessionInfo,
    IWithheld,
+    MigrationState,
    Mode,
    OutgoingRoomKeyRequest,
    ParkedSharedHistory,
    SecretStorePrivateKeys,
+    SESSION_BATCH_SIZE,
+    ACCOUNT_OBJECT_KEY_MIGRATION_STATE,
 } from "./base";
 import { IRoomKeyRequestBody, IRoomKeyRequestRecipient } from "../index";
 import { ICrossSigningKey } from "../../client";
 import { IOlmDevice } from "../algorithms/megolm";
 import { IRoomEncryption } from "../RoomList";
 import { InboundGroupSessionData } from "../OlmDevice";
+import { IndexedDBCryptoStore } from "./indexeddb-crypto-store";

 const PROFILE_TRANSACTIONS = false;

@@ -40,6 +45,8 @@ const PROFILE_TRANSACTIONS = false;
 * Implementation of a CryptoStore which is backed by an existing
 * IndexedDB connection. Generally you want IndexedDBCryptoStore
 * which connects to the database and defers to one of these.
+ *
+ * @internal
 */
 export class Backend implements CryptoStore {
    private nextTxnId = 0;
@@ -56,15 +63,49 @@ export class Backend implements CryptoStore {
        };
    }

+    public async containsData(): Promise<boolean> {
+        throw Error("Not implemented for Backend");
+    }
+
    public async startup(): Promise<CryptoStore> {
        // No work to do, as the startup is done by the caller (e.g IndexedDBCryptoStore)
        // by passing us a ready IDBDatabase instance
        return this;
    }
+
    public async deleteAllData(): Promise<void> {
        throw Error("This is not implemented, call IDBFactory::deleteDatabase(dbName) instead.");
    }

+    /**
+     * Get data on how much of the libolm to Rust Crypto migration has been done.
+     *
+     * Implementation of {@link CryptoStore.getMigrationState}.
+     */
+    public async getMigrationState(): Promise<MigrationState> {
+        let migrationState = MigrationState.NOT_STARTED;
+        await this.doTxn("readonly", [IndexedDBCryptoStore.STORE_ACCOUNT], (txn) => {
+            const objectStore = txn.objectStore(IndexedDBCryptoStore.STORE_ACCOUNT);
+            const getReq = objectStore.get(ACCOUNT_OBJECT_KEY_MIGRATION_STATE);
+            getReq.onsuccess = (): void => {
+                migrationState = getReq.result ?? MigrationState.NOT_STARTED;
+            };
+        });
+        return migrationState;
+    }
+
+    /**
+     * Set data on how much of the libolm to Rust Crypto migration has been done.
+     *
+     * Implementation of {@link CryptoStore.setMigrationState}.
+     */
+    public async setMigrationState(migrationState: MigrationState): Promise<void> {
+        await this.doTxn("readwrite", [IndexedDBCryptoStore.STORE_ACCOUNT], (txn) => {
+            const objectStore = txn.objectStore(IndexedDBCryptoStore.STORE_ACCOUNT);
+            objectStore.put(migrationState, ACCOUNT_OBJECT_KEY_MIGRATION_STATE);
+        });
+    }
+
    /**
     * Look for an existing outgoing room key request, and if none is found,
     * add a new one
@@ -588,6 +629,62 @@ export class Backend implements CryptoStore {
        return ret;
    }

+    /**
+     * Fetch a batch of Olm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.getEndToEndSessionsBatch}.
+     */
+    public async getEndToEndSessionsBatch(): Promise<null | ISessionInfo[]> {
+        const result: ISessionInfo[] = [];
+        await this.doTxn("readonly", [IndexedDBCryptoStore.STORE_SESSIONS], (txn) => {
+            const objectStore = txn.objectStore(IndexedDBCryptoStore.STORE_SESSIONS);
+            const getReq = objectStore.openCursor();
+            getReq.onsuccess = function (): void {
+                try {
+                    const cursor = getReq.result;
+                    if (cursor) {
+                        result.push(cursor.value);
+                        if (result.length < SESSION_BATCH_SIZE) {
+                            cursor.continue();
+                        }
+                    }
+                } catch (e) {
+                    abortWithException(txn, <Error>e);
+                }
+            };
+        });
+
+        if (result.length === 0) {
+            // No sessions left.
+            return null;
+        }
+
+        return result;
+    }
+
+    /**
+     * Delete a batch of Olm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.deleteEndToEndSessionsBatch}.
+     *
+     * @internal
+     */
+    public async deleteEndToEndSessionsBatch(sessions: { deviceKey: string; sessionId: string }[]): Promise<void> {
+        await this.doTxn("readwrite", [IndexedDBCryptoStore.STORE_SESSIONS], async (txn) => {
+            try {
+                const objectStore = txn.objectStore(IndexedDBCryptoStore.STORE_SESSIONS);
+                for (const { deviceKey, sessionId } of sessions) {
+                    const req = objectStore.delete([deviceKey, sessionId]);
+                    await new Promise((resolve) => {
+                        req.onsuccess = resolve;
+                    });
+                }
+            } catch (e) {
+                abortWithException(txn, <Error>e);
+            }
+        });
+    }
+
    // Inbound group sessions

    public getEndToEndInboundGroupSession(
@@ -712,6 +809,97 @@ export class Backend implements CryptoStore {
        });
    }

+    /**
+     * Count the number of Megolm sessions in the database.
+     *
+     * Implementation of {@link CryptoStore.countEndToEndInboundGroupSessions}.
+     *
+     * @internal
+     */
+    public async countEndToEndInboundGroupSessions(): Promise<number> {
+        let result = 0;
+        await this.doTxn("readonly", [IndexedDBCryptoStore.STORE_INBOUND_GROUP_SESSIONS], (txn) => {
+            const sessionStore = txn.objectStore(IndexedDBCryptoStore.STORE_INBOUND_GROUP_SESSIONS);
+            const countReq = sessionStore.count();
+            countReq.onsuccess = (): void => {
+                result = countReq.result;
+            };
+        });
+        return result;
+    }
+
+    /**
+     * Fetch a batch of Megolm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.getEndToEndInboundGroupSessionsBatch}.
+     */
+    public async getEndToEndInboundGroupSessionsBatch(): Promise<null | SessionExtended[]> {
+        const result: SessionExtended[] = [];
+        await this.doTxn(
+            "readonly",
+            [IndexedDBCryptoStore.STORE_INBOUND_GROUP_SESSIONS, IndexedDBCryptoStore.STORE_BACKUP],
+            (txn) => {
+                const sessionStore = txn.objectStore(IndexedDBCryptoStore.STORE_INBOUND_GROUP_SESSIONS);
+                const backupStore = txn.objectStore(IndexedDBCryptoStore.STORE_BACKUP);
+
+                const getReq = sessionStore.openCursor();
+                getReq.onsuccess = function (): void {
+                    try {
+                        const cursor = getReq.result;
+                        if (cursor) {
+                            const backupGetReq = backupStore.get(cursor.key);
+                            backupGetReq.onsuccess = (): void => {
+                                result.push({
+                                    senderKey: cursor.value.senderCurve25519Key,
+                                    sessionId: cursor.value.sessionId,
+                                    sessionData: cursor.value.session,
+                                    needsBackup: backupGetReq.result !== undefined,
+                                });
+                                if (result.length < SESSION_BATCH_SIZE) {
+                                    cursor.continue();
+                                }
+                            };
+                        }
+                    } catch (e) {
+                        abortWithException(txn, <Error>e);
+                    }
+                };
+            },
+        );
+
+        if (result.length === 0) {
+            // No sessions left.
+            return null;
+        }
+
+        return result;
+    }
+
+    /**
+     * Delete a batch of Megolm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.deleteEndToEndInboundGroupSessionsBatch}.
+     *
+     * @internal
+     */
+    public async deleteEndToEndInboundGroupSessionsBatch(
+        sessions: { senderKey: string; sessionId: string }[],
+    ): Promise<void> {
+        await this.doTxn("readwrite", [IndexedDBCryptoStore.STORE_INBOUND_GROUP_SESSIONS], async (txn) => {
+            try {
+                const objectStore = txn.objectStore(IndexedDBCryptoStore.STORE_INBOUND_GROUP_SESSIONS);
+                for (const { senderKey, sessionId } of sessions) {
+                    const req = objectStore.delete([senderKey, sessionId]);
+                    await new Promise((resolve) => {
+                        req.onsuccess = resolve;
+                    });
+                }
+            } catch (e) {
+                abortWithException(txn, <Error>e);
+            }
+        });
+    }
+
    public getEndToEndDeviceData(txn: IDBTransaction, func: (deviceData: IDeviceData | null) => void): void {
        const objectStore = txn.objectStore("device_data");
        const getReq = objectStore.get("-");
@@ -25,12 +25,15 @@ import {
    IDeviceData,
    IProblem,
    ISession,
+    SessionExtended,
    ISessionInfo,
    IWithheld,
+    MigrationState,
    Mode,
    OutgoingRoomKeyRequest,
    ParkedSharedHistory,
    SecretStorePrivateKeys,
+    ACCOUNT_OBJECT_KEY_MIGRATION_STATE,
 } from "./base";
 import { IRoomKeyRequestBody } from "../index";
 import { ICrossSigningKey } from "../../client";
@@ -38,7 +41,7 @@ import { IOlmDevice } from "../algorithms/megolm";
 import { IRoomEncryption } from "../RoomList";
 import { InboundGroupSessionData } from "../OlmDevice";

-/**
+/*
 * Internal module. indexeddb storage for e2e.
 */

@@ -61,6 +64,52 @@ export class IndexedDBCryptoStore implements CryptoStore {
        return IndexedDBHelpers.exists(indexedDB, dbName);
    }

+    /**
+     * Utility to check if a legacy crypto store exists and has not been migrated.
+     * Returns true if the store exists and has not been migrated, false otherwise.
+     */
+    public static existsAndIsNotMigrated(indexedDb: IDBFactory, dbName: string): Promise<boolean> {
+        return new Promise<boolean>((resolve, reject) => {
+            let exists = true;
+            const openDBRequest = indexedDb.open(dbName);
+            openDBRequest.onupgradeneeded = (): void => {
+                // Since we did not provide an explicit version when opening, this event
+                // should only fire if the DB did not exist before at any version.
+                exists = false;
+            };
+            openDBRequest.onblocked = (): void => reject(openDBRequest.error);
+            openDBRequest.onsuccess = (): void => {
+                const db = openDBRequest.result;
+                if (!exists) {
+                    db.close();
+                    // The DB did not exist before, but has been created as part of this
+                    // existence check. Delete it now to restore previous state. Delete can
+                    // actually take a while to complete in some browsers, so don't wait for
+                    // it. This won't block future open calls that a store might issue next to
+                    // properly set up the DB.
+                    indexedDb.deleteDatabase(dbName);
+                    resolve(false);
+                } else {
+                    const tx = db.transaction([IndexedDBCryptoStore.STORE_ACCOUNT], "readonly");
+                    const objectStore = tx.objectStore(IndexedDBCryptoStore.STORE_ACCOUNT);
+                    const getReq = objectStore.get(ACCOUNT_OBJECT_KEY_MIGRATION_STATE);
+
+                    getReq.onsuccess = (): void => {
+                        const migrationState = getReq.result ?? MigrationState.NOT_STARTED;
+                        resolve(migrationState === MigrationState.NOT_STARTED);
+                    };
+
+                    getReq.onerror = (): void => {
+                        reject(getReq.error);
+                    };
+
+                    db.close();
+                }
+            };
+            openDBRequest.onerror = (): void => reject(openDBRequest.error);
+        });
+    }
+
    private backendPromise?: Promise<CryptoStore>;
    private backend?: CryptoStore;

@@ -70,7 +119,21 @@ export class IndexedDBCryptoStore implements CryptoStore {
     * @param indexedDB -  global indexedDB instance
     * @param dbName -   name of db to connect to
     */
-    public constructor(private readonly indexedDB: IDBFactory, private readonly dbName: string) {}
+    public constructor(
+        private readonly indexedDB: IDBFactory,
+        private readonly dbName: string,
+    ) {}
+
+    /**
+     * Returns true if this CryptoStore has ever been initialised (ie, it might contain data).
+     *
+     * Implementation of {@link CryptoStore.containsData}.
+     *
+     * @internal
+     */
+    public async containsData(): Promise<boolean> {
+        return IndexedDBCryptoStore.exists(this.indexedDB, this.dbName);
+    }

    /**
     * Ensure the database exists and is up-to-date, or fall back to
@@ -197,6 +260,28 @@ export class IndexedDBCryptoStore implements CryptoStore {
        });
    }

+    /**
+     * Get data on how much of the libolm to Rust Crypto migration has been done.
+     *
+     * Implementation of {@link CryptoStore.getMigrationState}.
+     *
+     * @internal
+     */
+    public getMigrationState(): Promise<MigrationState> {
+        return this.backend!.getMigrationState();
+    }
+
+    /**
+     * Set data on how much of the libolm to Rust Crypto migration has been done.
+     *
+     * Implementation of {@link CryptoStore.setMigrationState}.
+     *
+     * @internal
+     */
+    public setMigrationState(migrationState: MigrationState): Promise<void> {
+        return this.backend!.setMigrationState(migrationState);
+    }
+
    /**
     * Look for an existing outgoing room key request, and if none is found,
     * add a new one
@@ -468,6 +553,39 @@ export class IndexedDBCryptoStore implements CryptoStore {
        return this.backend!.filterOutNotifiedErrorDevices(devices);
    }

+    /**
+     * Count the number of Megolm sessions in the database.
+     *
+     * Implementation of {@link CryptoStore.countEndToEndInboundGroupSessions}.
+     *
+     * @internal
+     */
+    public countEndToEndInboundGroupSessions(): Promise<number> {
+        return this.backend!.countEndToEndInboundGroupSessions();
+    }
+
+    /**
+     * Fetch a batch of Olm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.getEndToEndSessionsBatch}.
+     *
+     * @internal
+     */
+    public getEndToEndSessionsBatch(): Promise<null | ISessionInfo[]> {
+        return this.backend!.getEndToEndSessionsBatch();
+    }
+
+    /**
+     * Delete a batch of Olm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.deleteEndToEndSessionsBatch}.
+     *
+     * @internal
+     */
+    public deleteEndToEndSessionsBatch(sessions: { deviceKey: string; sessionId: string }[]): Promise<void> {
+        return this.backend!.deleteEndToEndSessionsBatch(sessions);
+    }
+
    // Inbound group sessions

    /**
@@ -544,6 +662,30 @@ export class IndexedDBCryptoStore implements CryptoStore {
        this.backend!.storeEndToEndInboundGroupSessionWithheld(senderCurve25519Key, sessionId, sessionData, txn);
    }

+    /**
+     * Fetch a batch of Megolm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.getEndToEndInboundGroupSessionsBatch}.
+     *
+     * @internal
+     */
+    public getEndToEndInboundGroupSessionsBatch(): Promise<SessionExtended[] | null> {
+        return this.backend!.getEndToEndInboundGroupSessionsBatch();
+    }
+
+    /**
+     * Delete a batch of Megolm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.deleteEndToEndInboundGroupSessionsBatch}.
+     *
+     * @internal
+     */
+    public deleteEndToEndInboundGroupSessionsBatch(
+        sessions: { senderKey: string; sessionId: string }[],
+    ): Promise<void> {
+        return this.backend!.deleteEndToEndInboundGroupSessionsBatch(sessions);
+    }
+
    // End-to-end device tracking

    /**
@@ -16,7 +16,19 @@ limitations under the License.

 import { logger } from "../../logger";
 import { MemoryCryptoStore } from "./memory-crypto-store";
-import { IDeviceData, IProblem, ISession, ISessionInfo, IWithheld, Mode, SecretStorePrivateKeys } from "./base";
+import {
+    CryptoStore,
+    IDeviceData,
+    IProblem,
+    ISession,
+    SessionExtended,
+    ISessionInfo,
+    IWithheld,
+    MigrationState,
+    Mode,
+    SecretStorePrivateKeys,
+    SESSION_BATCH_SIZE,
+} from "./base";
 import { IOlmDevice } from "../algorithms/megolm";
 import { IRoomEncryption } from "../RoomList";
 import { ICrossSigningKey } from "../../client";
@@ -32,6 +44,7 @@ import { safeSet } from "../../utils";
 */

 const E2E_PREFIX = "crypto.";
+const KEY_END_TO_END_MIGRATION_STATE = E2E_PREFIX + "migration";
 const KEY_END_TO_END_ACCOUNT = E2E_PREFIX + "account";
 const KEY_CROSS_SIGNING_KEYS = E2E_PREFIX + "cross_signing_keys";
 const KEY_NOTIFIED_ERROR_DEVICES = E2E_PREFIX + "notified_error_devices";
@@ -61,7 +74,7 @@ function keyEndToEndRoomsPrefix(roomId: string): string {
    return KEY_ROOMS_PREFIX + roomId;
 }

-export class LocalStorageCryptoStore extends MemoryCryptoStore {
+export class LocalStorageCryptoStore extends MemoryCryptoStore implements CryptoStore {
    public static exists(store: Storage): boolean {
        const length = store.length;
        for (let i = 0; i < length; i++) {
@@ -76,12 +89,49 @@ export class LocalStorageCryptoStore extends MemoryCryptoStore {
        super();
    }

+    /**
+     * Returns true if this CryptoStore has ever been initialised (ie, it might contain data).
+     *
+     * Implementation of {@link CryptoStore.containsData}.
+     *
+     * @internal
+     */
+    public async containsData(): Promise<boolean> {
+        return LocalStorageCryptoStore.exists(this.store);
+    }
+
+    /**
+     * Get data on how much of the libolm to Rust Crypto migration has been done.
+     *
+     * Implementation of {@link CryptoStore.getMigrationState}.
+     *
+     * @internal
+     */
+    public async getMigrationState(): Promise<MigrationState> {
+        return getJsonItem(this.store, KEY_END_TO_END_MIGRATION_STATE) ?? MigrationState.NOT_STARTED;
+    }
+
+    /**
+     * Set data on how much of the libolm to Rust Crypto migration has been done.
+     *
+     * Implementation of {@link CryptoStore.setMigrationState}.
+     *
+     * @internal
+     */
+    public async setMigrationState(migrationState: MigrationState): Promise<void> {
+        setJsonItem(this.store, KEY_END_TO_END_MIGRATION_STATE, migrationState);
+    }
+
    // Olm Sessions

    public countEndToEndSessions(txn: unknown, func: (count: number) => void): void {
        let count = 0;
        for (let i = 0; i < this.store.length; ++i) {
-            if (this.store.key(i)?.startsWith(keyEndToEndSessions(""))) ++count;
+            const key = this.store.key(i);
+            if (key?.startsWith(keyEndToEndSessions(""))) {
+                const sessions = getJsonItem(this.store, key);
+                count += Object.keys(sessions ?? {}).length;
+            }
        }
        func(count);
    }
@@ -192,6 +242,56 @@ export class LocalStorageCryptoStore extends MemoryCryptoStore {
        return ret;
    }

+    /**
+     * Fetch a batch of Olm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.getEndToEndSessionsBatch}.
+     *
+     * @internal
+     */
+    public async getEndToEndSessionsBatch(): Promise<null | ISessionInfo[]> {
+        const result: ISessionInfo[] = [];
+        for (let i = 0; i < this.store.length; ++i) {
+            if (this.store.key(i)?.startsWith(keyEndToEndSessions(""))) {
+                const deviceKey = this.store.key(i)!.split("/")[1];
+                for (const session of Object.values(this._getEndToEndSessions(deviceKey))) {
+                    result.push(session);
+                    if (result.length >= SESSION_BATCH_SIZE) {
+                        return result;
+                    }
+                }
+            }
+        }
+
+        if (result.length === 0) {
+            // No sessions left.
+            return null;
+        }
+
+        // There are fewer sessions than the batch size; return the final batch of sessions.
+        return result;
+    }
+
+    /**
+     * Delete a batch of Olm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.deleteEndToEndSessionsBatch}.
+     *
+     * @internal
+     */
+    public async deleteEndToEndSessionsBatch(sessions: { deviceKey: string; sessionId: string }[]): Promise<void> {
+        for (const { deviceKey, sessionId } of sessions) {
+            const deviceSessions = this._getEndToEndSessions(deviceKey) || {};
+            delete deviceSessions[sessionId];
+            if (Object.keys(deviceSessions).length === 0) {
+                // No more sessions for this device.
+                this.store.removeItem(keyEndToEndSessions(deviceKey));
+            } else {
+                setJsonItem(this.store, keyEndToEndSessions(deviceKey), deviceSessions);
+            }
+        }
+    }
+
    // Inbound Group Sessions

    public getEndToEndInboundGroupSession(
@@ -255,6 +355,82 @@ export class LocalStorageCryptoStore extends MemoryCryptoStore {
        setJsonItem(this.store, keyEndToEndInboundGroupSessionWithheld(senderCurve25519Key, sessionId), sessionData);
    }

+    /**
+     * Count the number of Megolm sessions in the database.
+     *
+     * Implementation of {@link CryptoStore.countEndToEndInboundGroupSessions}.
+     *
+     * @internal
+     */
+    public async countEndToEndInboundGroupSessions(): Promise<number> {
+        let count = 0;
+        for (let i = 0; i < this.store.length; ++i) {
+            const key = this.store.key(i);
+            if (key?.startsWith(KEY_INBOUND_SESSION_PREFIX)) {
+                count += 1;
+            }
+        }
+        return count;
+    }
+
+    /**
+     * Fetch a batch of Megolm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.getEndToEndInboundGroupSessionsBatch}.
+     *
+     * @internal
+     */
+    public async getEndToEndInboundGroupSessionsBatch(): Promise<SessionExtended[] | null> {
+        const sessionsNeedingBackup = getJsonItem<string[]>(this.store, KEY_SESSIONS_NEEDING_BACKUP) || {};
+        const result: SessionExtended[] = [];
+        for (let i = 0; i < this.store.length; ++i) {
+            const key = this.store.key(i);
+            if (key?.startsWith(KEY_INBOUND_SESSION_PREFIX)) {
+                const key2 = key.slice(KEY_INBOUND_SESSION_PREFIX.length);
+
+                // we can't use split, as the components we are trying to split out
+                // might themselves contain '/' characters. We rely on the
+                // senderKey being a (32-byte) curve25519 key, base64-encoded
+                // (hence 43 characters long).
+
+                result.push({
+                    senderKey: key2.slice(0, 43),
+                    sessionId: key2.slice(44),
+                    sessionData: getJsonItem(this.store, key)!,
+                    needsBackup: key2 in sessionsNeedingBackup,
+                });
+
+                if (result.length >= SESSION_BATCH_SIZE) {
+                    return result;
+                }
+            }
+        }
+
+        if (result.length === 0) {
+            // No sessions left.
+            return null;
+        }
+
+        // There are fewer sessions than the batch size; return the final batch of sessions.
+        return result;
+    }
+
+    /**
+     * Delete a batch of Megolm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.deleteEndToEndInboundGroupSessionsBatch}.
+     *
+     * @internal
+     */
+    public async deleteEndToEndInboundGroupSessionsBatch(
+        sessions: { senderKey: string; sessionId: string }[],
+    ): Promise<void> {
+        for (const { senderKey, sessionId } of sessions) {
+            const k = keyEndToEndInboundGroupSession(senderKey, sessionId);
+            this.store.removeItem(k);
+        }
+    }
+
    public getEndToEndDeviceData(txn: unknown, func: (deviceData: IDeviceData | null) => void): void {
        func(getJsonItem(this.store, KEY_DEVICE_DATA));
    }
@@ -15,18 +15,21 @@ limitations under the License.
 */

 import { logger } from "../../logger";
-import { safeSet, deepCompare, promiseTry } from "../../utils";
+import { deepCompare, promiseTry, safeSet } from "../../utils";
 import {
    CryptoStore,
    IDeviceData,
    IProblem,
    ISession,
+    SessionExtended,
    ISessionInfo,
    IWithheld,
+    MigrationState,
    Mode,
    OutgoingRoomKeyRequest,
    ParkedSharedHistory,
    SecretStorePrivateKeys,
+    SESSION_BATCH_SIZE,
 } from "./base";
 import { IRoomKeyRequestBody } from "../index";
 import { ICrossSigningKey } from "../../client";
@@ -39,6 +42,7 @@ import { InboundGroupSessionData } from "../OlmDevice";
 */

 export class MemoryCryptoStore implements CryptoStore {
+    private migrationState: MigrationState = MigrationState.NOT_STARTED;
    private outgoingRoomKeyRequests: OutgoingRoomKeyRequest[] = [];
    private account: string | null = null;
    private crossSigningKeys: Record<string, ICrossSigningKey> | null = null;
@@ -56,6 +60,18 @@ export class MemoryCryptoStore implements CryptoStore {
    private sharedHistoryInboundGroupSessions: { [roomId: string]: [senderKey: string, sessionId: string][] } = {};
    private parkedSharedHistory = new Map<string, ParkedSharedHistory[]>(); // keyed by room ID

+    /**
+     * Returns true if this CryptoStore has ever been initialised (ie, it might contain data).
+     *
+     * Implementation of {@link CryptoStore.containsData}.
+     *
+     * @internal
+     */
+    public async containsData(): Promise<boolean> {
+        // If it contains anything, it should contain an account.
+        return this.account !== null;
+    }
+
    /**
     * Ensure the database exists and is up-to-date.
     *
@@ -77,6 +93,28 @@ export class MemoryCryptoStore implements CryptoStore {
        return Promise.resolve();
    }

+    /**
+     * Get data on how much of the libolm to Rust Crypto migration has been done.
+     *
+     * Implementation of {@link CryptoStore.getMigrationState}.
+     *
+     * @internal
+     */
+    public async getMigrationState(): Promise<MigrationState> {
+        return this.migrationState;
+    }
+
+    /**
+     * Set data on how much of the libolm to Rust Crypto migration has been done.
+     *
+     * Implementation of {@link CryptoStore.setMigrationState}.
+     *
+     * @internal
+     */
+    public async setMigrationState(migrationState: MigrationState): Promise<void> {
+        this.migrationState = migrationState;
+    }
+
    /**
     * Look for an existing outgoing room key request, and if none is found,
     * add a new one
@@ -298,7 +336,11 @@ export class MemoryCryptoStore implements CryptoStore {
    // Olm Sessions

    public countEndToEndSessions(txn: unknown, func: (count: number) => void): void {
-        func(Object.keys(this.sessions).length);
+        let count = 0;
+        for (const deviceSessions of Object.values(this.sessions)) {
+            count += Object.keys(deviceSessions).length;
+        }
+        func(count);
    }

    public getEndToEndSession(
@@ -386,6 +428,51 @@ export class MemoryCryptoStore implements CryptoStore {
        return ret;
    }

+    /**
+     * Fetch a batch of Olm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.getEndToEndSessionsBatch}.
+     *
+     * @internal
+     */
+    public async getEndToEndSessionsBatch(): Promise<null | ISessionInfo[]> {
+        const result: ISessionInfo[] = [];
+        for (const deviceSessions of Object.values(this.sessions)) {
+            for (const session of Object.values(deviceSessions)) {
+                result.push(session);
+                if (result.length >= SESSION_BATCH_SIZE) {
+                    return result;
+                }
+            }
+        }
+
+        if (result.length === 0) {
+            // No sessions left.
+            return null;
+        }
+
+        // There are fewer sessions than the batch size; return the final batch of sessions.
+        return result;
+    }
+
+    /**
+     * Delete a batch of Olm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.deleteEndToEndSessionsBatch}.
+     *
+     * @internal
+     */
+    public async deleteEndToEndSessionsBatch(sessions: { deviceKey: string; sessionId: string }[]): Promise<void> {
+        for (const { deviceKey, sessionId } of sessions) {
+            const deviceSessions = this.sessions[deviceKey] || {};
+            delete deviceSessions[sessionId];
+            if (Object.keys(deviceSessions).length === 0) {
+                // No more sessions for this device.
+                delete this.sessions[deviceKey];
+            }
+        }
+    }
+
    // Inbound Group Sessions

    public getEndToEndInboundGroupSession(
@@ -445,6 +532,63 @@ export class MemoryCryptoStore implements CryptoStore {
        this.inboundGroupSessionsWithheld[k] = sessionData;
    }

+    /**
+     * Count the number of Megolm sessions in the database.
+     *
+     * Implementation of {@link CryptoStore.countEndToEndInboundGroupSessions}.
+     *
+     * @internal
+     */
+    public async countEndToEndInboundGroupSessions(): Promise<number> {
+        return Object.keys(this.inboundGroupSessions).length;
+    }
+
+    /**
+     * Fetch a batch of Megolm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.getEndToEndInboundGroupSessionsBatch}.
+     *
+     * @internal
+     */
+    public async getEndToEndInboundGroupSessionsBatch(): Promise<null | SessionExtended[]> {
+        const result: SessionExtended[] = [];
+        for (const [key, session] of Object.entries(this.inboundGroupSessions)) {
+            result.push({
+                senderKey: key.slice(0, 43),
+                sessionId: key.slice(44),
+                sessionData: session,
+                needsBackup: key in this.sessionsNeedingBackup,
+            });
+            if (result.length >= SESSION_BATCH_SIZE) {
+                return result;
+            }
+        }
+
+        if (result.length === 0) {
+            // No sessions left.
+            return null;
+        }
+
+        // There are fewer sessions than the batch size; return the final batch of sessions.
+        return result;
+    }
+
+    /**
+     * Delete a batch of Megolm sessions from the database.
+     *
+     * Implementation of {@link CryptoStore.deleteEndToEndInboundGroupSessionsBatch}.
+     *
+     * @internal
+     */
+    public async deleteEndToEndInboundGroupSessionsBatch(
+        sessions: { senderKey: string; sessionId: string }[],
+    ): Promise<void> {
+        for (const { senderKey, sessionId } of sessions) {
+            const k = senderKey + "/" + sessionId;
+            delete this.inboundGroupSessions[k];
+        }
+    }
+
    // Device Data

    public getEndToEndDeviceData(txn: unknown, func: (deviceData: IDeviceData | null) => void): void {
@@ -137,12 +137,15 @@ export class VerificationBase<
        if (this.transactionTimeoutTimer !== null) {
            clearTimeout(this.transactionTimeoutTimer);
        }
-        this.transactionTimeoutTimer = setTimeout(() => {
-            if (!this._done && !this.cancelled) {
-                logger.info("Triggering verification timeout");
-                this.cancel(timeoutException);
-            }
-        }, 10 * 60 * 1000); // 10 minutes
+        this.transactionTimeoutTimer = setTimeout(
+            () => {
+                if (!this._done && !this.cancelled) {
+                    logger.info("Triggering verification timeout");
+                    this.cancel(timeoutException);
+                }
+            },
+            10 * 60 * 1000,
+        ); // 10 minutes
    }

    private endTimer(): void {
@@ -39,7 +39,11 @@ export class InRoomChannel implements IVerificationChannel {
     * @param roomId - id of the room where verification events should be posted in, should be a DM with the given user.
     * @param userId - id of user that the verification request is directed at, should be present in the room.
     */
-    public constructor(private readonly client: MatrixClient, public readonly roomId: string, public userId?: string) {}
+    public constructor(
+        private readonly client: MatrixClient,
+        public readonly roomId: string,
+        public userId?: string,
+    ) {}

    public get receiveStartFromOtherDevices(): boolean {
        return true;
@@ -21,7 +21,10 @@ export enum InvalidStoreState {
 export class InvalidStoreError extends Error {
    public static TOGGLED_LAZY_LOADING = InvalidStoreState.ToggledLazyLoading;

-    public constructor(public readonly reason: InvalidStoreState, public readonly value: any) {
+    public constructor(
+        public readonly reason: InvalidStoreState,
+        public readonly value: any,
+    ) {
        const message =
            `Store is invalid because ${reason}, ` +
            `please stop the client, delete all data and start the client again`;
@@ -47,7 +50,10 @@ export class InvalidCryptoStoreError extends Error {
 }

 export class KeySignatureUploadError extends Error {
-    public constructor(message: string, public readonly value: any) {
+    public constructor(
+        message: string,
+        public readonly value: any,
+    ) {
        super(message);
    }
 }
@@ -62,7 +62,10 @@ export interface IFilterComponent {
 * 'Filters' are referred to as 'FilterCollections'.
 */
 export class FilterComponent {
-    public constructor(private filterJson: IFilterComponent, public readonly userId?: string | undefined | null) {}
+    public constructor(
+        private filterJson: IFilterComponent,
+        public readonly userId?: string | undefined | null,
+    ) {}

    /**
     * Checks with the filter component matches the given event
@@ -92,7 +92,10 @@ export class Filter {
     * @param userId - The user ID for this filter.
     * @param filterId - The filter ID if known.
     */
-    public constructor(public readonly userId: string | undefined | null, public filterId?: string) {}
+    public constructor(
+        public readonly userId: string | undefined | null,
+        public filterId?: string,
+    ) {}

    /**
     * Get the ID of this filter on your homeserver (if known)
@@ -30,7 +30,10 @@ interface IErrorJson extends Partial<IUsageLimit> {
 * @param httpStatus - The HTTP response status code.
 */
 export class HTTPError extends Error {
-    public constructor(msg: string, public readonly httpStatus?: number) {
+    public constructor(
+        msg: string,
+        public readonly httpStatus?: number,
+    ) {
        super(msg);
    }
 }
@@ -33,8 +33,8 @@ interface TypedResponse<T> extends Response {
 export type ResponseType<T, O extends IHttpOpts> = O extends undefined
    ? T
    : O extends { onlyData: true }
-    ? T
-    : TypedResponse<T>;
+      ? T
+      : TypedResponse<T>;

 export class FetchHttpApi<O extends IHttpOpts> {
    private abortController = new AbortController();
@@ -40,7 +40,7 @@ export enum MediaPrefix {
    /**
     * A constant representing the URI path for Client-Server API Media endpoints versioned at v1.
     */
-    V1 = "/_matrix/media/v3",
+    V1 = "/_matrix/media/v1",
    /**
     * A constant representing the URI path for Client-Server API Media endpoints versioned at v3.
     */
--- a/Show More
+++ b/Show More