v35.0.0-rc.0

* Update matrix-sdk-crypto-wasm to 11.0.0

* use `backend` variable to test for rust crypto

* apply changes from review

.eslintrc.cjs

@@ -138,6 +138,7 @@ module.exports = {
                         tryExtensions: [".ts"],
                     },
                 ],
+                "no-extra-boolean-cast": "error",
             },
         },
         {

.github/PULL_REQUEST_TEMPLATE.md

@@ -2,7 +2,7 @@
 
 ## Checklist
 
--   [ ] Tests written for new code (and old code if feasible).
--   [ ] New or updated `public`/`exported` symbols have accurate [TSDoc](https://tsdoc.org/) documentation.
--   [ ] 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)).
+- [ ] Tests written for new code (and old code if feasible).
+- [ ] New or updated `public`/`exported` symbols have accurate [TSDoc](https://tsdoc.org/) documentation.
+- [ ] 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)).

.github/actions/sign-release-tarball/action.yml

@@ -22,7 +22,7 @@ runs:
 
         - name: Upload tarball signature
           if: ${{ inputs.upload-url }}
-          uses: shogo82148/actions-upload-release-asset@aac270e08f6b4547ada0b3800f88e1eb3ce9d400 # v1
+          uses: shogo82148/actions-upload-release-asset@8482bd769644976d847e96fb4b9354228885e7b4 # v1
           with:
               upload_url: ${{ inputs.upload-url }}
               asset_path: ${{ env.VERSION }}.tar.gz.asc

.github/actions/upload-release-assets/action.yml

@@ -29,13 +29,13 @@ runs:
 
         - name: Upload asset signatures
           if: inputs.gpg-fingerprint
-          uses: shogo82148/actions-upload-release-asset@aac270e08f6b4547ada0b3800f88e1eb3ce9d400 # v1
+          uses: shogo82148/actions-upload-release-asset@8482bd769644976d847e96fb4b9354228885e7b4 # v1
           with:
               upload_url: ${{ inputs.upload-url }}
               asset_path: ${{ inputs.asset-path }}.asc
 
         - name: Upload assets
-          uses: shogo82148/actions-upload-release-asset@aac270e08f6b4547ada0b3800f88e1eb3ce9d400 # v1
+          uses: shogo82148/actions-upload-release-asset@8482bd769644976d847e96fb4b9354228885e7b4 # v1
           with:
               upload_url: ${{ inputs.upload-url }}
               asset_path: ${{ inputs.asset-path }}

.github/workflows/backport.yml

@@ -7,6 +7,8 @@ on:
         branches:
             - develop
 
+permissions: {} # We use ELEMENT_BOT_TOKEN instead
+
 jobs:
     backport:
         name: Backport

.github/workflows/docs-pr-netlify.yaml

@@ -5,16 +5,19 @@ on:
         workflows: ["Static Analysis"]
         types:
             - completed
-
+permissions: {}
 jobs:
     netlify:
         if: github.event.workflow_run.conclusion == 'success' && github.event.workflow_run.event == 'pull_request'
         runs-on: ubuntu-24.04
+        permissions:
+            actions: read
+            deployments: write
         steps:
             - name: 📥 Download artifact
               uses: actions/download-artifact@v4
               with:
-                  github-token: ${{ secrets.ELEMENT_BOT_TOKEN }}
+                  github-token: ${{ secrets.GITHUB_TOKEN }}
                   run-id: ${{ github.event.workflow_run.id }}
                   name: docs
                   path: docs

.github/workflows/downstream-end-to-end-tests.yml

@@ -13,7 +13,7 @@ on:
     #
     #push:
     #    branches: [develop, master]
-
+permissions: {} # No permissions required
 concurrency:
     group: ${{ github.workflow }}-${{ github.event.workflow_run.head_branch || github.run_id }}
     cancel-in-progress: ${{ github.event.workflow_run.event == 'pull_request' }}

.github/workflows/notify-downstream.yaml

@@ -3,6 +3,7 @@ on:
     push:
         branches: [develop]
 concurrency: ${{ github.workflow }}-${{ github.ref }}
+permissions: {} # We use ELEMENT_BOT_TOKEN instead
 jobs:
     notify-downstream:
         # Only respect triggers from our develop branch, ignore that of forks

.github/workflows/pull_request.yaml

@@ -9,6 +9,7 @@ on:
             ELEMENT_BOT_TOKEN:
                 required: true
 concurrency: ${{ github.workflow }}-${{ github.event.pull_request.head.ref || github.head_ref || github.ref }}
+permissions: {} # We use ELEMENT_BOT_TOKEN instead
 jobs:
     changelog:
         name: Preview Changelog
@@ -44,6 +45,8 @@ jobs:
         name: Label Community PRs
         runs-on: ubuntu-24.04
         if: github.event.action == 'opened'
+        permissions:
+            pull-requests: write
         steps:
             - name: Check membership
               if: github.event.pull_request.user.login != 'renovate[bot]'

.github/workflows/release-checks.yml

@@ -0,0 +1,38 @@
+name: Release Sanity checks
+on:
+    workflow_call:
+        secrets:
+            ELEMENT_BOT_TOKEN:
+                required: false
+        inputs:
+            repository:
+                type: string
+                required: false
+                default: ${{ github.repository }}
+                description: "The repository (in form owner/repo) to check for release blockers"
+
+permissions: {}
+jobs:
+    checks:
+        name: Sanity checks
+        runs-on: ubuntu-24.04
+        steps:
+            - name: Check for X-Release-Blocker label on any open issues or PRs
+              uses: actions/github-script@v7
+              env:
+                  REPO: ${{ inputs.repository }}
+              with:
+                  github-token: ${{ secrets.ELEMENT_BOT_TOKEN || secrets.GITHUB_TOKEN }}
+                  script: |
+                      const { REPO } = process.env;
+                      const { data } = await github.rest.search.issuesAndPullRequests({
+                          q: `repo:${REPO} label:X-Release-Blocker is:open`,
+                          per_page: 50,
+                      });
+
+                      if (data.total_count) {
+                          data.items.forEach(item => {
+                              core.error(`Release blocker: ${item.html_url}`);
+                          });
+                          core.setFailed(`Found release blockers!`);
+                      }

.github/workflows/release-drafter-workflow.yml

@@ -8,9 +8,12 @@ on:
                 type: string
                 required: false
 concurrency: release-drafter-action
+permissions: {}
 jobs:
     draft:
         runs-on: ubuntu-24.04
+        permissions:
+            contents: write
         steps:
             - name: 🧮 Checkout code
               uses: actions/checkout@v4

.github/workflows/release-drafter.yml

@@ -8,6 +8,9 @@ on:
         branches: [staging]
     workflow_dispatch: {}
 concurrency: ${{ github.workflow }}
+permissions: {}
 jobs:
     draft:
+        permissions:
+            contents: write
         uses: matrix-org/matrix-js-sdk/.github/workflows/release-drafter-workflow.yml@develop

.github/workflows/release-gitflow.yml

@@ -13,12 +13,14 @@ on:
                 type: string
                 required: false
 concurrency: ${{ github.workflow }}
+permissions: {} # Uses ELEMENT_BOT_TOKEN
 jobs:
     merge:
         runs-on: ubuntu-24.04
         steps:
             - uses: actions/checkout@v4
               with:
+                  # We will be pushing to this branch and want the CI to run after we do so we cannot use the GITHUB_TOKEN
                   token: ${{ secrets.ELEMENT_BOT_TOKEN }}
                   fetch-depth: 0
 

.github/workflows/release-make.yml

@@ -20,10 +20,6 @@ on:
                 description: Publish to npm
                 type: boolean
                 default: false
-            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
             gpg-fingerprint:
                 description: Fingerprint of the GPG key to use for signing the git tag and assets, if any.
                 type: string
@@ -38,16 +34,31 @@ on:
                 description: The number of expected assets, including signatures, excluding generated zip & tarball.
                 type: number
                 required: false
+        outputs:
+            npm-id:
+                description: "The npm package@version string we published"
+                value: ${{ jobs.npm.outputs.id }}
+permissions: {}
 jobs:
+    checks:
+        name: Sanity checks
+        permissions:
+            issues: read
+            pull-requests: read
+        uses: matrix-org/matrix-js-sdk/.github/workflows/release-checks.yml@develop
+
     release:
         name: Release
         runs-on: ubuntu-24.04
         environment: Release
+        needs: checks
+        permissions:
+            contents: write
         steps:
             - name: Load GPG key
               id: gpg
               if: inputs.gpg-fingerprint
-              uses: crazy-max/ghaction-import-gpg@01dd5d3ca463c7f10f7f4f7b4f177225ac661ee4 # v6
+              uses: crazy-max/ghaction-import-gpg@cb9bde2e2525e640591a934b1fd28eef1dcaf5e5 # v6
               with:
                   gpg_private_key: ${{ secrets.GPG_PRIVATE_KEY }}
                   passphrase: ${{ secrets.GPG_PASSPHRASE }}
@@ -65,6 +76,7 @@ jobs:
             - uses: actions/checkout@v4
               with:
                   ref: staging
+                  # We will be pushing to this branch and want the CI to run after we do so we cannot use the GITHUB_TOKEN
                   token: ${{ secrets.ELEMENT_BOT_TOKEN }}
                   fetch-depth: 0
 
@@ -274,6 +286,8 @@ jobs:
         name: Post release steps
         needs: release
         runs-on: ubuntu-24.04
+        permissions:
+            issues: write
         steps:
             - id: repository
               run: echo "REPO=${GITHUB_REPOSITORY#*/}" >> $GITHUB_OUTPUT
@@ -297,34 +311,3 @@ jobs:
     #                  wait-interval: 10
     #                  check-name: merge
     #                  allowed-conclusions: success
-
-    bump-downstreams:
-        name: Update npm dependency in downstream projects
-        needs: npm
-        runs-on: ubuntu-24.04
-        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 }}
-
-            - uses: actions/setup-node@v4
-              with:
-                  cache: "yarn"
-                  node-version: "lts/*"
-
-            - 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

.github/workflows/release-npm.yml

@@ -8,6 +8,7 @@ on:
             id:
                 description: "The npm package@version string we published"
                 value: ${{ jobs.npm.outputs.id }}
+permissions: {} # No permissions required
 jobs:
     npm:
         name: Publish to npm

.github/workflows/release.yml

@@ -21,14 +21,49 @@ on:
                 type: boolean
                 default: true
 concurrency: ${{ github.workflow }}
+permissions: {} # No permissions required
 jobs:
     release:
         uses: matrix-org/matrix-js-sdk/.github/workflows/release-make.yml@develop
+        permissions:
+            contents: write
+            issues: write
+            pull-requests: read
         secrets: inherit
         with:
             final: ${{ inputs.mode == 'final' }}
             npm: ${{ inputs.npm }}
-            downstreams: '["element-hq/element-web"]'
+
+    bump-downstreams:
+        name: Update npm dependency in downstream projects
+        needs: release
+        runs-on: ubuntu-24.04
+        strategy:
+            matrix:
+                repo:
+                    - element-hq/element-web
+        steps:
+            - uses: actions/checkout@v4
+              with:
+                  repository: ${{ matrix.repo }}
+                  ref: staging
+                  token: ${{ secrets.ELEMENT_BOT_TOKEN }}
+
+            - uses: actions/setup-node@v4
+              with:
+                  cache: "yarn"
+                  node-version: "lts/*"
+
+            - name: Bump dependency
+              env:
+                  DEPENDENCY: ${{ needs.release.outputs.npm-id }}
+              run: |
+                  git config --global user.email "releases@riot.im"
+                  git config --global user.name "RiotRobot"
+                  yarn upgrade "$DEPENDENCY" --exact
+                  git add package.json yarn.lock
+                  git commit -am"Upgrade dependency to $DEPENDENCY"
+                  git push origin staging
 
     docs:
         name: Publish Documentation

.github/workflows/sonarcloud.yml

@@ -5,23 +5,29 @@ on:
         secrets:
             SONAR_TOKEN:
                 required: true
+            # No longer used
             ELEMENT_BOT_TOKEN:
-                required: true
+                required: false
         inputs:
             sharded:
                 type: boolean
                 required: false
                 description: "Whether to combine multiple LCOV and jest-sonar-report files in coverage artifact"
+permissions: {}
 jobs:
     sonarqube:
         runs-on: ubuntu-24.04
         if: |
             github.event.workflow_run.conclusion == 'success' &&
             github.event.workflow_run.event != 'merge_group'
+        permissions:
+            actions: read
+            statuses: write
+            id-token: write # sonar
         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 Sonarcloud is done.
-            - uses: Sibz/github-status-action@071b5370da85afbb16637d6eed8524a06bc2053e # v1
+            - uses: guibranco/github-status-action-v2@66088c44e212a906c32a047529a213d81809ec1c
               with:
                   authToken: ${{ secrets.GITHUB_TOKEN }}
                   state: pending
@@ -30,7 +36,7 @@ jobs:
                   target_url: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}
 
             - name: "🧮 Checkout code"
-              uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871 # v4
+              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
               with:
                   repository: ${{ github.event.workflow_run.head_repository.full_name }}
                   ref: ${{ github.event.workflow_run.head_branch }} # checkout commit that triggered this workflow
@@ -40,7 +46,7 @@ jobs:
               uses: actions/download-artifact@v4
               if: ${{ !inputs.sharded }}
               with:
-                  github-token: ${{ secrets.ELEMENT_BOT_TOKEN }}
+                  github-token: ${{ secrets.GITHUB_TOKEN }}
                   run-id: ${{ github.event.workflow_run.id }}
                   name: coverage
                   path: coverage
@@ -48,11 +54,17 @@ jobs:
               uses: actions/download-artifact@v4
               if: inputs.sharded
               with:
-                  github-token: ${{ secrets.ELEMENT_BOT_TOKEN }}
+                  github-token: ${{ secrets.GITHUB_TOKEN }}
                   run-id: ${{ github.event.workflow_run.id }}
                   pattern: coverage-*
                   path: coverage
                   merge-multiple: true
+            - name: Check coverage artifact
+              run: |
+                  if [ ! -d coverage ]; then
+                      echo "Coverage not found. Exiting with failure."
+                      exit 1
+                  fi
 
             - id: extra_args
               run: |
@@ -75,7 +87,7 @@ jobs:
                   revision: ${{ github.event.workflow_run.head_sha }}
                   token: ${{ secrets.SONAR_TOKEN }}
 
-            - uses: Sibz/github-status-action@071b5370da85afbb16637d6eed8524a06bc2053e # v1
+            - uses: guibranco/github-status-action-v2@66088c44e212a906c32a047529a213d81809ec1c
               if: always()
               with:
                   authToken: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/sonarqube.yml

@@ -7,10 +7,15 @@ on:
 concurrency:
     group: ${{ github.workflow }}-${{ github.event.workflow_run.head_branch }}
     cancel-in-progress: true
+permissions: {}
 jobs:
     sonarqube:
         name: 🩻 SonarQube
         if: github.event.workflow_run.conclusion == 'success' && github.event.workflow_run.event != 'merge_group'
+        permissions:
+            actions: read
+            statuses: write
+            id-token: write # sonar
         uses: matrix-org/matrix-js-sdk/.github/workflows/sonarcloud.yml@develop
         secrets:
             SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}

.github/workflows/static_analysis.yml

@@ -8,6 +8,7 @@ on:
 concurrency:
     group: ${{ github.workflow }}-${{ github.ref }}
     cancel-in-progress: true
+permissions: {} # No permissions needed
 jobs:
     ts_lint:
         name: "Typescript Syntax Check"
@@ -101,3 +102,37 @@ jobs:
 
             - name: Run linter
               run: "yarn run lint:knip"
+
+    element-web:
+        name: Downstream tsc element-web
+        if: github.event_name == 'merge_group'
+        runs-on: ubuntu-24.04
+        steps:
+            - uses: actions/checkout@v4
+              with:
+                  repository: element-hq/element-web
+
+            - uses: actions/setup-node@v4
+              with:
+                  cache: "yarn"
+                  node-version: "lts/*"
+
+            - name: Install Dependencies
+              run: "./scripts/layered.sh"
+              env:
+                  # tell layered.sh to check out the right sha of the JS-SDK
+                  JS_SDK_GITHUB_BASE_REF: ${{ github.sha }}
+
+            - name: Typecheck
+              run: "yarn run lint:types"
+
+    # Hook for branch protection to skip downstream typechecking outside of merge queues
+    downstream:
+        name: Downstream Typescript Syntax Check
+        runs-on: ubuntu-24.04
+        if: always()
+        needs:
+            - element-web
+        steps:
+            - if: needs.element-web.result != 'skipped' && needs.element-web.result != 'success'
+              run: exit 1

.github/workflows/sync-labels.yml

@@ -8,6 +8,7 @@ on:
             - develop
         paths:
             - .github/labels.yml
+permissions: {} # We use ELEMENT_BOT_TOKEN instead
 jobs:
     sync-labels:
         uses: element-hq/element-meta/.github/workflows/sync-labels.yml@develop

.github/workflows/tests.yml

@@ -10,6 +10,7 @@ concurrency:
     cancel-in-progress: true
 env:
     ENABLE_COVERAGE: ${{ github.event_name != 'merge_group' }}
+permissions: {} # No permissions required
 jobs:
     jest:
         name: "Jest [${{ matrix.specs }}] (Node ${{ matrix.node == '*' && 'latest' || matrix.node }})"
@@ -77,6 +78,8 @@ jobs:
         name: Downstream test element-web
         if: github.event_name == 'merge_group'
         uses: element-hq/element-web/.github/workflows/tests.yml@develop
+        permissions:
+            statuses: write
         with:
             disable_coverage: true
             matrix-js-sdk-sha: ${{ github.sha }}
@@ -84,6 +87,7 @@ jobs:
     complement-crypto:
         name: "Run Complement Crypto tests"
         if: github.event_name == 'merge_group'
+        permissions: read-all
         uses: matrix-org/complement-crypto/.github/workflows/single_sdk_tests.yml@main
         with:
             use_js_sdk: "."
@@ -107,10 +111,12 @@ jobs:
         if: always()
         needs:
             - element-web
+        permissions:
+            statuses: write
         steps:
             - name: Skip SonarCloud on merge queues
               if: env.ENABLE_COVERAGE == 'false'
-              uses: Sibz/github-status-action@071b5370da85afbb16637d6eed8524a06bc2053e # v1
+              uses: guibranco/github-status-action-v2@66088c44e212a906c32a047529a213d81809ec1c
               with:
                   authToken: ${{ secrets.GITHUB_TOKEN }}
                   state: success

.github/workflows/triage-incoming.yml

@@ -3,7 +3,7 @@ name: Move new issues into Issue triage board
 on:
     issues:
         types: [opened]
-
+permissions: {} # We use ELEMENT_BOT_TOKEN instead
 jobs:
     automate-project-columns-next:
         runs-on: ubuntu-24.04

.github/workflows/triage-labelled.yml

@@ -3,7 +3,7 @@ name: Move labelled issues to correct projects
 on:
     issues:
         types: [labeled]
-
+permissions: {} # We use ELEMENT_BOT_TOKEN instead
 jobs:
     call-triage-labelled:
         uses: element-hq/element-web/.github/workflows/triage-labelled.yml@develop

CHANGELOG.md

@@ -1,3 +1,22 @@
+Changes in [34.13.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v34.13.0) (2024-12-03)
+====================================================================================================
+## 🦖 Deprecations
+
+* Deprecate `MatrixClient.isEventSenderVerified` ([#4527](https://github.com/matrix-org/matrix-js-sdk/pull/4527)). Contributed by @florianduros.
+* Add `restoreKeybackup` to `CryptoApi`. ([#4476](https://github.com/matrix-org/matrix-js-sdk/pull/4476)). Contributed by @florianduros.
+
+## ✨ Features
+
+* Ensure we disambiguate display names which look like MXIDs ([#4540](https://github.com/matrix-org/matrix-js-sdk/pull/4540)). Contributed by @t3chguy.
+* Add `CryptoApi.getBackupInfo` ([#4512](https://github.com/matrix-org/matrix-js-sdk/pull/4512)). Contributed by @florianduros.
+* Fix local echo in embedded mode ([#4498](https://github.com/matrix-org/matrix-js-sdk/pull/4498)). Contributed by @toger5.
+* Add `restoreKeybackup` to `CryptoApi`. ([#4476](https://github.com/matrix-org/matrix-js-sdk/pull/4476)). Contributed by @florianduros.
+
+## 🐛 Bug Fixes
+
+* Fix `RustBackupManager` remaining values after current backup removal ([#4537](https://github.com/matrix-org/matrix-js-sdk/pull/4537)). Contributed by @florianduros.
+
+
 Changes in [34.12.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v34.12.0) (2024-11-19)
 ====================================================================================================
 ## 🦖 Deprecations

README.md

@@ -38,8 +38,8 @@ client.publicRooms(function (err, data) {
 });
 ```
 
-See below for how to include libolm to enable end-to-end-encryption. Please check
-[the Node.js terminal app](examples/node/README.md) for a more complex example.
+See [below](#end-to-end-encryption-support) for how to enable end-to-end-encryption, or check
+[the Node.js terminal app](https://github.com/matrix-org/matrix-js-sdk/tree/develop/examples/node) for a more complex example.
 
 To start the client:
 
@@ -126,26 +126,26 @@ const img = await fetch(downloadUrl, {
 This SDK provides a full object model around the Matrix Client-Server API and emits
 events for incoming data and state changes. Aside from wrapping the HTTP API, it:
 
--   Handles syncing (via `/sync`)
--   Handles the generation of "friendly" room and member names.
--   Handles historical `RoomMember` information (e.g. display names).
--   Manages room member state across multiple events (e.g. it handles typing, power
-    levels and membership changes).
--   Exposes high-level objects like `Rooms`, `RoomState`, `RoomMembers` and `Users`
-    which can be listened to for things like name changes, new messages, membership
-    changes, presence changes, and more.
--   Handle "local echo" of messages sent using the SDK. This means that messages
-    that have just been sent will appear in the timeline as 'sending', until it
-    completes. This is beneficial because it prevents there being a gap between
-    hitting the send button and having the "remote echo" arrive.
--   Mark messages which failed to send as not sent.
--   Automatically retry requests to send messages due to network errors.
--   Automatically retry requests to send messages due to rate limiting errors.
--   Handle queueing of messages.
--   Handles pagination.
--   Handle assigning push actions for events.
--   Handles room initial sync on accepting invites.
--   Handles WebRTC calling.
+- Handles syncing (via `/sync`)
+- Handles the generation of "friendly" room and member names.
+- Handles historical `RoomMember` information (e.g. display names).
+- Manages room member state across multiple events (e.g. it handles typing, power
+  levels and membership changes).
+- Exposes high-level objects like `Rooms`, `RoomState`, `RoomMembers` and `Users`
+  which can be listened to for things like name changes, new messages, membership
+  changes, presence changes, and more.
+- Handle "local echo" of messages sent using the SDK. This means that messages
+  that have just been sent will appear in the timeline as 'sending', until it
+  completes. This is beneficial because it prevents there being a gap between
+  hitting the send button and having the "remote echo" arrive.
+- Mark messages which failed to send as not sent.
+- Automatically retry requests to send messages due to network errors.
+- Automatically retry requests to send messages due to rate limiting errors.
+- Handle queueing of messages.
+- Handles pagination.
+- Handle assigning push actions for events.
+- Handles room initial sync on accepting invites.
+- Handles WebRTC calling.
 
 # Usage
 
@@ -303,44 +303,131 @@ Then visit `http://localhost:8005` to see the API docs.
 
 # End-to-end encryption support
 
-**This section is outdated.** Use of `libolm` is deprecated and we are replacing it with support
-from the matrix-rust-sdk (https://github.com/element-hq/element-web/issues/21972).
+`matrix-js-sdk`'s end-to-end encryption support is based on the [WebAssembly bindings](https://github.com/matrix-org/matrix-rust-sdk-crypto-wasm) of the Rust [matrix-sdk-crypto](https://github.com/matrix-org/matrix-rust-sdk/tree/main/crates/matrix-sdk-crypto) library.
 
-The SDK supports end-to-end encryption via the Olm and Megolm protocols, using
-[libolm](https://gitlab.matrix.org/matrix-org/olm). It is left up to the
-application to make libolm available, via the `Olm` global.
+## Initialization
 
-It is also necessary to call `await matrixClient.initCrypto()` after creating a new
-`MatrixClient` (but **before** calling `matrixClient.startClient()`) to
-initialise the crypto layer.
+**Do not use `matrixClient.initLegacyCrypto()`. This method is deprecated and no longer maintained.**
 
-If the `Olm` global is not available, the SDK will show a warning, as shown
-below; `initCrypto()` will also fail.
+To initialize the end-to-end encryption support in the matrix client:
 
-```
-Unable to load crypto module: crypto will be disabled: Error: global.Olm is not defined
+```javascript
+// Create a new matrix client
+const matrixClient = sdk.createClient({
+    baseUrl: "http://localhost:8008",
+    accessToken: myAccessToken,
+    userId: myUserId,
+});
+
+// Initialize to enable end-to-end encryption support.
+await matrixClient.initRustCrypto();
 ```
 
-If the crypto layer is not (successfully) initialised, the SDK will continue to
-work for unencrypted rooms, but it will not support the E2E parts of the Matrix
-specification.
+After calling `initRustCrypto`, you can obtain a reference to the [`CryptoApi`](https://matrix-org.github.io/matrix-js-sdk/interfaces/crypto_api.CryptoApi.html) interface, which is the main entry point for end-to-end encryption, by calling [`MatrixClient.getCrypto`](https://matrix-org.github.io/matrix-js-sdk/classes/matrix.MatrixClient.html#getCrypto).
 
-To provide the Olm library in a browser application:
+**WARNING**: the cryptography stack is not thread-safe. Having multiple `MatrixClient` instances connected to the same Indexed DB will cause data corruption and decryption failures. The application layer is responsible for ensuring that only one `MatrixClient` issue is instantiated at a time.
 
--   download the transpiled libolm (from https://packages.matrix.org/npm/olm/).
--   load `olm.js` as a `<script>` _before_ `browser-matrix.js`.
+## Secret storage
 
-To provide the Olm library in a node.js application:
+You should normally set up [secret storage](https://spec.matrix.org/v1.12/client-server-api/#secret-storage) before using the end-to-end encryption. To do this, call [`CryptoApi.bootstrapSecretStorage`](https://matrix-org.github.io/matrix-js-sdk/interfaces/crypto_api.CryptoApi.html#bootstrapSecretStorage).
+`bootstrapSecretStorage` can be called unconditionally: it will only set up the secret storage if it is not already set up (unless you use the `setupNewSecretStorage` parameter).
 
--   `yarn add https://packages.matrix.org/npm/olm/olm-3.1.4.tgz`
-    (replace the URL with the latest version you want to use from
-    https://packages.matrix.org/npm/olm/)
--   `global.Olm = require('olm');` _before_ loading `matrix-js-sdk`.
+```javascript
+const matrixClient = sdk.createClient({
+    ...,
+    cryptoCallbacks: {
+        getSecretStorageKey: async (keys) => {
+            // This function should prompt the user to enter their secret storage key.
+            return mySecretStorageKeys;
+        },
+    },
+});
 
-If you want to package Olm as dependency for your node.js application, you can
-use `yarn add https://packages.matrix.org/npm/olm/olm-3.1.4.tgz`. If your
-application also works without e2e crypto enabled, add `--optional` to mark it
-as an optional dependency.
+matrixClient.getCrypto().bootstrapSecretStorage({
+    // This function will be called if a new secret storage key (aka recovery key) is needed.
+    // You should prompt the user to save the key somewhere, because they will need it to unlock secret storage in future.
+    createSecretStorageKey: async () => {
+        return mySecretStorageKey;
+    },
+});
+```
+
+The example above will create a new secret storage key if secret storage was not previously set up.
+The secret storage data will be encrypted using the secret storage key returned in [`createSecretStorageKey`](https://matrix-org.github.io/matrix-js-sdk/interfaces/crypto_api.CreateSecretStorageOpts.html#createSecretStorageKey).
+
+We recommend that you prompt the user to re-enter this key when [`CryptoCallbacks.getSecretStorageKey`](https://matrix-org.github.io/matrix-js-sdk/interfaces/crypto_api.CryptoCallbacks.html#getSecretStorageKey) is called (when the secret storage access is needed).
+
+## Set up cross-signing
+
+To set up cross-signing to verify devices and other users, call
+[`CryptoApi.bootstrapCrossSigning`](https://matrix-org.github.io/matrix-js-sdk/interfaces/crypto_api.CryptoApi.html#bootstrapCrossSigning):
+
+```javascript
+matrixClient.getCrypto().bootstrapCrossSigning({
+    authUploadDeviceSigningKeys: async (makeRequest) => {
+        return makeRequest(authDict);
+    },
+});
+```
+
+The [`authUploadDeviceSigningKeys`](https://matrix-org.github.io/matrix-js-sdk/interfaces/crypto_api.BootstrapCrossSigningOpts.html#authUploadDeviceSigningKeys)
+callback is required in order to upload newly-generated public cross-signing keys to the server.
+
+## Key backup
+
+If the user doesn't already have a [key backup](https://spec.matrix.org/v1.12/client-server-api/#server-side-key-backups) you should create one:
+
+```javascript
+// Check if we have a key backup.
+// If checkKeyBackupAndEnable returns null, there is no key backup.
+const hasKeyBackup = (await matrixClient.getCrypto().checkKeyBackupAndEnable()) !== null;
+
+// Create the key backup
+await matrixClient.getCrypto().resetKeyBackup();
+```
+
+## Verify a new device
+
+Once the cross-signing is set up on one of your devices, you can verify another device with two methods:
+
+1. Use `CryptoApi.bootstrapCrossSigning`.
+
+    `bootstrapCrossSigning` will call the [CryptoCallbacks.getSecretStorageKey](https://matrix-org.github.io/matrix-js-sdk/interfaces/crypto_api.CryptoCallbacks.html#getSecretStorageKey) callback. The device is verified with the private cross-signing keys fetched from the secret storage.
+
+2. Request an interactive verification against existing devices, by calling [CryptoApi.requestOwnUserVerification](https://matrix-org.github.io/matrix-js-sdk/interfaces/crypto_api.CryptoApi.html#requestOwnUserVerification).
+
+## Migrating from the legacy crypto stack to Rust crypto
+
+If your application previously used the legacy crypto stack, (i.e, it called `MatrixClient.initLegacyCrypto()`), you will
+need to migrate existing devices to the Rust crypto stack.
+
+This migration happens automatically when you call `initRustCrypto()` instead of `initLegacyCrypto()`,
+but you need to provide the legacy [`cryptoStore`](https://matrix-org.github.io/matrix-js-sdk/interfaces/matrix.ICreateClientOpts.html#cryptoStore) and [`pickleKey`](https://matrix-org.github.io/matrix-js-sdk/interfaces/matrix.ICreateClientOpts.html#pickleKey) to [`createClient`](https://matrix-org.github.io/matrix-js-sdk/functions/matrix.createClient.html):
+
+```javascript
+// You should provide the legacy crypto store and the pickle key to the matrix client in order to migrate the data.
+const matrixClient = sdk.createClient({
+    cryptoStore: myCryptoStore,
+    pickleKey: myPickleKey,
+    baseUrl: "http://localhost:8008",
+    accessToken: myAccessToken,
+    userId: myUserId,
+});
+
+// The migration will be done automatically when you call `initRustCrypto`.
+await matrixClient.initRustCrypto();
+```
+
+To follow the migration progress, you can listen to the [`CryptoEvent.LegacyCryptoStoreMigrationProgress`](https://matrix-org.github.io/matrix-js-sdk/enums/crypto_api.CryptoEvent.html#LegacyCryptoStoreMigrationProgress) event:
+
+```javascript
+// When progress === total === -1, the migration is finished.
+matrixClient.on(CryptoEvent.LegacyCryptoStoreMigrationProgress, (progress, total) => {
+    ...
+});
+```
+
+The Rust crypto stack is not supported in a lot of deprecated methods of [`MatrixClient`](https://matrix-org.github.io/matrix-js-sdk/classes/matrix.MatrixClient.html). If you use them, you should migrate to the [`CryptoApi`](https://matrix-org.github.io/matrix-js-sdk/interfaces/crypto_api.CryptoApi.html). Also, the legacy `MatrixClient.crypto` object is not available any more: you should use `MatrixClient.getCrypto()` instead.
 
 # Contributing
 

docs/SUMMARY.md

@@ -1,8 +1,8 @@
 # Summary
 
--   [Introduction](../README.md)
+- [Introduction](../README.md)
 
 # Deep dive
 
--   [Storage notes](storage-notes.md)
--   [Unverified devices](warning-on-unverified-devices.md)
+- [Storage notes](storage-notes.md)
+- [Unverified devices](warning-on-unverified-devices.md)

docs/storage-notes.md

@@ -20,19 +20,19 @@ blurrier.
 
 When we are low on disk space overall or near the group limit / origin quota:
 
--   Chrome
-    -   Log database may fail to start with AbortError
-    -   IndexedDB fails to start for crypto: AbortError in connect from
-        indexeddb-store-worker
-    -   When near the quota, QuotaExceededError is used more consistently
--   Firefox
-    -   The first error will be QuotaExceededError
-    -   Future write attempts will fail with various errors when space is low,
-        including nonsense like "InvalidStateError: A mutation operation was
-        attempted on a database that did not allow mutations."
-    -   Once you start getting errors, the DB is effectively wedged in read-only
-        mode
-    -   Can revive access if you reopen the DB
+- Chrome
+    - Log database may fail to start with AbortError
+    - IndexedDB fails to start for crypto: AbortError in connect from
+      indexeddb-store-worker
+    - When near the quota, QuotaExceededError is used more consistently
+- Firefox
+    - The first error will be QuotaExceededError
+    - Future write attempts will fail with various errors when space is low,
+      including nonsense like "InvalidStateError: A mutation operation was
+      attempted on a database that did not allow mutations."
+    - Once you start getting errors, the DB is effectively wedged in read-only
+      mode
+    - Can revive access if you reopen the DB
 
 ## Cache Eviction
 
@@ -41,9 +41,9 @@ limited by a single quota, in practice, browsers appear to handle `localStorage`
 separately from the others, so it has a separate quota limit and isn't evicted
 when low on space.
 
--   Chrome, Firefox
-    -   IndexedDB for origin deleted
-    -   Local Storage remains in place
+- Chrome, Firefox
+    - IndexedDB for origin deleted
+    - Local Storage remains in place
 
 ## Persistent Storage
 
@@ -51,20 +51,20 @@ Storage Standard offers a `navigator.storage.persist` API that can be used to
 request persistent storage that won't be deleted by the browser because of low
 space.
 
--   Chrome
-    -   Chrome 75 seems to grant this without any prompt based on [interaction
-        criteria](https://developers.google.com/web/updates/2016/06/persistent-storage)
--   Firefox
-    -   Firefox 67 shows a prompt to grant
-    -   Reverting persistent seems to require revoking permission _and_ clearing
-        site data
+- Chrome
+    - Chrome 75 seems to grant this without any prompt based on [interaction
+      criteria](https://developers.google.com/web/updates/2016/06/persistent-storage)
+- Firefox
+    - Firefox 67 shows a prompt to grant
+    - Reverting persistent seems to require revoking permission _and_ clearing
+      site data
 
 ## Storage Estimation
 
 Storage Standard offers a `navigator.storage.estimate` API to get some clue of
 how much space remains.
 
--   Chrome, Firefox
-    -   Can run this at any time to request an estimate of space remaining
--   Firefox
-    -   Returns `0` for `usage` if a site is persisted
+- Chrome, Firefox
+    - Can run this at any time to request an estimate of space remaining
+- Firefox
+    - Returns `0` for `usage` if a site is persisted

docs/warning-on-unverified-devices.md

@@ -17,13 +17,13 @@ Warn when you initial sync if the room has any new undefined devices since you w
 
 Warn when the user tries to send a message:
 
--   If the room has unverified devices which the user has not yet been told about in the context of this room
-    ...or in the context of this user? currently all verification is per-user, not per-room.
-    ...this should be good enough.
+- If the room has unverified devices which the user has not yet been told about in the context of this room
+  ...or in the context of this user? currently all verification is per-user, not per-room.
+  ...this should be good enough.
 
--   so track whether we have warned the user or not about unverified devices - blocked, unverified, verified, unverified_warned.
-    throw an error when trying to encrypt if there are pure unverified devices there
-    app will have to search for the devices which are pure unverified to warn about them - have to do this from MembersList anyway?
-    -   or megolm could warn which devices are causing the problems.
+- so track whether we have warned the user or not about unverified devices - blocked, unverified, verified, unverified_warned.
+  throw an error when trying to encrypt if there are pure unverified devices there
+  app will have to search for the devices which are pure unverified to warn about them - have to do this from MembersList anyway?
+    - or megolm could warn which devices are causing the problems.
 
 Why do we wait to establish outbound sessions? It just makes a horrible pause when we first try to send a message... but could otherwise unnecessarily consume resources?

package.json

@@ -1,6 +1,6 @@
 {
     "name": "matrix-js-sdk",
-    "version": "34.12.0",
+    "version": "35.0.0-rc.0",
     "description": "Matrix Client-Server SDK for Javascript",
     "engines": {
         "node": ">=20.0.0"
@@ -50,7 +50,7 @@
     ],
     "dependencies": {
         "@babel/runtime": "^7.12.5",
-        "@matrix-org/matrix-sdk-crypto-wasm": "^9.0.0",
+        "@matrix-org/matrix-sdk-crypto-wasm": "^11.0.0",
         "@matrix-org/olm": "3.2.15",
         "another-json": "^0.2.0",
         "bs58": "^6.0.0",
@@ -103,7 +103,7 @@
         "eslint-plugin-jsdoc": "^50.0.0",
         "eslint-plugin-matrix-org": "^2.0.1",
         "eslint-plugin-n": "^14.0.0",
-        "eslint-plugin-tsdoc": "^0.3.0",
+        "eslint-plugin-tsdoc": "^0.4.0",
         "eslint-plugin-unicorn": "^56.0.0",
         "fake-indexeddb": "^5.0.2",
         "fetch-mock": "11.1.5",
@@ -117,12 +117,12 @@
         "lint-staged": "^15.0.2",
         "matrix-mock-request": "^2.5.0",
         "node-fetch": "^2.7.0",
-        "prettier": "3.3.3",
+        "prettier": "3.4.1",
         "rimraf": "^6.0.0",
         "ts-node": "^10.9.2",
-        "typedoc": "^0.26.0",
+        "typedoc": "^0.27.0",
         "typedoc-plugin-coverage": "^3.0.0",
-        "typedoc-plugin-mdn-links": "^3.0.3",
+        "typedoc-plugin-mdn-links": "^4.0.0",
         "typedoc-plugin-missing-exports": "^3.0.0",
         "typescript": "^5.4.2"
     },

spec/integ/crypto/crypto.spec.ts

@@ -1327,7 +1327,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
 
             const syncResponse = getSyncResponse(["@bob:xyz"]);
             // Every 2 messages in the room, the session should be rotated
-            syncResponse.rooms[Category.Join][ROOM_ID].state.events[0].content = {
+            syncResponse.rooms[Category.Join][ROOM_ID].state!.events[0].content = {
                 algorithm: "m.megolm.v1.aes-sha2",
                 rotation_period_msgs: 2,
             };
@@ -1383,7 +1383,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
             const oneHourInMs = 60 * 60 * 1000;
 
             // Every 1h the session should be rotated
-            syncResponse.rooms[Category.Join][ROOM_ID].state.events[0].content = {
+            syncResponse.rooms[Category.Join][ROOM_ID].state!.events[0].content = {
                 algorithm: "m.megolm.v1.aes-sha2",
                 rotation_period_ms: oneHourInMs,
             };
@@ -1741,7 +1741,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
             groupSession: groupSession,
             room_id: ROOM_ID,
         });
-        await testClient.client.initCrypto();
+        await testClient.client.initLegacyCrypto();
         const keys = [
             {
                 room_id: ROOM_ID,
@@ -1853,7 +1853,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
 
     oldBackendOnly("Alice receives shared history before being invited to a room by the sharer", async () => {
         const beccaTestClient = new TestClient("@becca:localhost", "foobar", "bazquux");
-        await beccaTestClient.client.initCrypto();
+        await beccaTestClient.client.initLegacyCrypto();
 
         expectAliceKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
         await startClientAndAwaitFirstSync();
@@ -2007,7 +2007,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
 
     oldBackendOnly("Alice receives shared history before being invited to a room by someone else", async () => {
         const beccaTestClient = new TestClient("@becca:localhost", "foobar", "bazquux");
-        await beccaTestClient.client.initCrypto();
+        await beccaTestClient.client.initLegacyCrypto();
 
         expectAliceKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
         await startClientAndAwaitFirstSync();

spec/integ/crypto/megolm-backup.spec.ts

@@ -22,7 +22,7 @@ import { Mocked } from "jest-mock";
 import {
     createClient,
     Crypto,
-    CryptoEvent,
+    encodeBase64,
     ICreateClientOpts,
     IEvent,
     IMegolmSessionData,
@@ -44,7 +44,7 @@ import * as testData from "../../test-utils/test-data";
 import { KeyBackupInfo, KeyBackupSession } from "../../../src/crypto-api/keybackup";
 import { flushPromises } from "../../test-utils/flushPromises";
 import { defer, IDeferred } from "../../../src/utils";
-import { DecryptionFailureCode } from "../../../src/crypto-api";
+import { decodeRecoveryKey, DecryptionFailureCode, CryptoEvent } from "../../../src/crypto-api";
 import { KeyBackup } from "../../../src/rust-crypto/backup.ts";
 
 const ROOM_ID = testData.TEST_ROOM_ID;
@@ -117,8 +117,10 @@ function mockUploadEmitter(
 describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backend: string, initCrypto: InitCrypto) => {
     // oldBackendOnly is an alternative to `it` or `test` which will skip the test if we are running against the
     // Rust backend. Once we have full support in the rust sdk, it will go away.
-    // const oldBackendOnly = backend === "rust-sdk" ? test.skip : test;
-    // const newBackendOnly = backend === "libolm" ? test.skip : test;
+    const oldBackendOnly = backend === "rust-sdk" ? test.skip : test;
+    const newBackendOnly = backend === "libolm" ? test.skip : test;
+
+    const isNewBackend = backend === "rust-sdk";
 
     let aliceClient: MatrixClient;
     /** an object which intercepts `/sync` requests on the test homeserver */
@@ -247,9 +249,9 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
             // On the first decryption attempt, decryption fails.
             await awaitDecryption(event);
             expect(event.decryptionFailureReason).toEqual(
-                backend === "libolm"
-                    ? DecryptionFailureCode.MEGOLM_UNKNOWN_INBOUND_SESSION_ID
-                    : DecryptionFailureCode.HISTORICAL_MESSAGE_WORKING_BACKUP,
+                isNewBackend
+                    ? DecryptionFailureCode.HISTORICAL_MESSAGE_WORKING_BACKUP
+                    : DecryptionFailureCode.MEGOLM_UNKNOWN_INBOUND_SESSION_ID,
             );
 
             // Eventually, decryption succeeds.
@@ -314,6 +316,10 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
 
         beforeEach(async () => {
             fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);
+            fetchMock.get(
+                `path:/_matrix/client/v3/room_keys/version/${testData.SIGNED_BACKUP_DATA.version}`,
+                testData.SIGNED_BACKUP_DATA,
+            );
 
             aliceClient = await initTestClient();
             aliceCrypto = aliceClient.getCrypto()!;
@@ -344,20 +350,29 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
                 onKeyCached = resolve;
             });
 
+            await aliceCrypto.storeSessionBackupPrivateKey(
+                decodeRecoveryKey(testData.BACKUP_DECRYPTION_KEY_BASE58),
+                check!.backupInfo!.version!,
+            );
+
             const result = await advanceTimersUntil(
-                aliceClient.restoreKeyBackupWithRecoveryKey(
-                    testData.BACKUP_DECRYPTION_KEY_BASE58,
-                    undefined,
-                    undefined,
-                    check!.backupInfo!,
-                    {
-                        cacheCompleteCallback: () => onKeyCached(),
-                    },
-                ),
+                isNewBackend
+                    ? aliceCrypto.restoreKeyBackup()
+                    : aliceClient.restoreKeyBackupWithRecoveryKey(
+                          testData.BACKUP_DECRYPTION_KEY_BASE58,
+                          undefined,
+                          undefined,
+                          check!.backupInfo!,
+                          {
+                              cacheCompleteCallback: () => onKeyCached(),
+                          },
+                      ),
             );
 
             expect(result.imported).toStrictEqual(1);
 
+            if (isNewBackend) return;
+
             await awaitKeyCached;
 
             // The key should be now cached
@@ -398,8 +413,13 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
 
         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;
+            if (isNewBackend) {
+                // @ts-ignore - mock a private method for testing purpose
+                jest.spyOn(aliceCrypto.backupManager, "importBackedUpRoomKeys").mockImplementation(importMockImpl);
+            } else {
+                // @ts-ignore - mock a private method for testing purpose
+                jest.spyOn(aliceCrypto, "importBackedUpRoomKeys").mockImplementation(importMockImpl);
+            }
 
             // We need several rooms with several sessions to test chunking
             const { response, expectedTotal } = createBackupDownloadResponse([45, 300, 345, 12, 130]);
@@ -408,17 +428,26 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
 
             const check = await aliceCrypto.checkKeyBackupAndEnable();
 
-            const progressCallback = jest.fn();
-            const result = await aliceClient.restoreKeyBackupWithRecoveryKey(
-                testData.BACKUP_DECRYPTION_KEY_BASE58,
-                undefined,
-                undefined,
-                check!.backupInfo!,
-                {
-                    progressCallback,
-                },
+            await aliceCrypto.storeSessionBackupPrivateKey(
+                decodeRecoveryKey(testData.BACKUP_DECRYPTION_KEY_BASE58),
+                check!.backupInfo!.version!,
             );
 
+            const progressCallback = jest.fn();
+            const result = await (isNewBackend
+                ? aliceCrypto.restoreKeyBackup({
+                      progressCallback,
+                  })
+                : 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);
@@ -451,8 +480,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
         });
 
         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
+            const importMockImpl = jest
                 .fn()
                 .mockImplementationOnce(() => {
                     // Fail to import first chunk
@@ -461,22 +489,36 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
                 // Ok for other chunks
                 .mockResolvedValue(undefined);
 
+            if (isNewBackend) {
+                // @ts-ignore - mock a private method for testing purpose
+                jest.spyOn(aliceCrypto.backupManager, "importBackedUpRoomKeys").mockImplementation(importMockImpl);
+            } else {
+                // @ts-ignore - mock a private method for testing purpose
+                jest.spyOn(aliceCrypto, "importBackedUpRoomKeys").mockImplementation(importMockImpl);
+            }
+
             const { response, expectedTotal } = createBackupDownloadResponse([100, 300]);
 
             fetchMock.get("express:/_matrix/client/v3/room_keys/keys", response);
 
             const check = await aliceCrypto.checkKeyBackupAndEnable();
+            await aliceCrypto.storeSessionBackupPrivateKey(
+                decodeRecoveryKey(testData.BACKUP_DECRYPTION_KEY_BASE58),
+                check!.backupInfo!.version!,
+            );
 
             const progressCallback = jest.fn();
-            const result = await aliceClient.restoreKeyBackupWithRecoveryKey(
-                testData.BACKUP_DECRYPTION_KEY_BASE58,
-                undefined,
-                undefined,
-                check!.backupInfo!,
-                {
-                    progressCallback,
-                },
-            );
+            const result = await (isNewBackend
+                ? aliceCrypto.restoreKeyBackup({ progressCallback })
+                : aliceClient.restoreKeyBackupWithRecoveryKey(
+                      testData.BACKUP_DECRYPTION_KEY_BASE58,
+                      undefined,
+                      undefined,
+                      check!.backupInfo!,
+                      {
+                          progressCallback,
+                      },
+                  ));
 
             expect(result.total).toStrictEqual(expectedTotal);
             // A chunk failed to import
@@ -527,20 +569,26 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
             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!,
+            await aliceCrypto.storeSessionBackupPrivateKey(
+                decodeRecoveryKey(testData.BACKUP_DECRYPTION_KEY_BASE58),
+                check!.backupInfo!.version!,
             );
 
+            const result = await (isNewBackend
+                ? aliceCrypto.restoreKeyBackup()
+                : 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 () {
+        oldBackendOnly("recover specific session from backup", async function () {
             fetchMock.get(
                 "express:/_matrix/client/v3/room_keys/keys/:room_id/:session_id",
                 testData.CURVE25519_KEY_BACKUP_DATA,
@@ -560,7 +608,33 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
             expect(result.imported).toStrictEqual(1);
         });
 
-        it("Fails on bad recovery key", async function () {
+        newBackendOnly(
+            "Should get the decryption key from the secret storage and restore the key backup",
+            async function () {
+                // @ts-ignore - mock a private method for testing purpose
+                jest.spyOn(aliceCrypto.secretStorage, "get").mockResolvedValue(testData.BACKUP_DECRYPTION_KEY_BASE64);
+
+                const fullBackup = {
+                    rooms: {
+                        [ROOM_ID]: {
+                            sessions: {
+                                [testData.MEGOLM_SESSION_DATA.session_id]: testData.CURVE25519_KEY_BACKUP_DATA,
+                            },
+                        },
+                    },
+                };
+                fetchMock.get("express:/_matrix/client/v3/room_keys/keys", fullBackup);
+
+                await aliceCrypto.loadSessionBackupPrivateKeyFromSecretStorage();
+                const decryptionKey = await aliceCrypto.getSessionBackupPrivateKey();
+                expect(encodeBase64(decryptionKey!)).toStrictEqual(testData.BACKUP_DECRYPTION_KEY_BASE64);
+
+                const result = await aliceCrypto.restoreKeyBackup();
+                expect(result.imported).toStrictEqual(1);
+            },
+        );
+
+        oldBackendOnly("Fails on bad recovery key", async function () {
             const fullBackup = {
                 rooms: {
                     [ROOM_ID]: {
@@ -584,6 +658,10 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
                 ),
             ).rejects.toThrow();
         });
+
+        newBackendOnly("Should throw an error if the decryption key is not found in cache", async () => {
+            await expect(aliceCrypto.restoreKeyBackup()).rejects.toThrow("No decryption key found in crypto store");
+        });
     });
 
     describe("backupLoop", () => {
@@ -890,6 +968,40 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("megolm-keys backup (%s)", (backe
         expect(backupStatus).toStrictEqual(testData.SIGNED_BACKUP_DATA.version);
     });
 
+    newBackendOnly("getKeyBackupInfo() should not return a backup if the active backup has been deleted", async () => {
+        // 404 means that there is no active backup
+        fetchMock.get("express:/_matrix/client/v3/room_keys/version", 404);
+        fetchMock.delete(`express:/_matrix/client/v3/room_keys/version/${testData.SIGNED_BACKUP_DATA.version}`, {});
+
+        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);
+        await aliceCrypto.checkKeyBackupAndEnable();
+
+        // At this point there is no backup
+        expect(await aliceCrypto.getKeyBackupInfo()).toBeNull();
+
+        // Return now the backup
+        fetchMock.get("express:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA, {
+            overwriteRoutes: true,
+        });
+
+        expect(await aliceCrypto.getKeyBackupInfo()).toStrictEqual(testData.SIGNED_BACKUP_DATA);
+
+        // Delete the backup and we are expecting the key backup to be disabled
+        const keyBackupStatus = defer<boolean>();
+        aliceClient.once(CryptoEvent.KeyBackupStatus, (enabled) => keyBackupStatus.resolve(enabled));
+        await aliceCrypto.deleteKeyBackupVersion(testData.SIGNED_BACKUP_DATA.version!);
+        expect(await keyBackupStatus.promise).toBe(false);
+
+        // The backup info should not be available anymore
+        expect(await aliceCrypto.getKeyBackupInfo()).toBeNull();
+    });
+
     describe("isKeyBackupTrusted", () => {
         it("does not trust a backup signed by an untrusted device", async () => {
             aliceClient = await initTestClient();

spec/integ/crypto/olm-encryption-spec.ts

@@ -345,10 +345,10 @@ describe("MatrixClient crypto", () => {
 
     beforeEach(async () => {
         aliTestClient = new TestClient(aliUserId, aliDeviceId, aliAccessToken);
-        await aliTestClient.client.initCrypto();
+        await aliTestClient.client.initLegacyCrypto();
 
         bobTestClient = new TestClient(bobUserId, bobDeviceId, bobAccessToken);
-        await bobTestClient.client.initCrypto();
+        await bobTestClient.client.initLegacyCrypto();
 
         aliMessages = [];
         bobMessages = [];

spec/integ/crypto/verification.spec.ts

@@ -78,6 +78,7 @@ import {
     encryptGroupSessionKey,
     encryptMegolmEvent,
     encryptSecretSend,
+    getTestOlmAccountKeys,
     ToDeviceEvent,
 } from "./olm-utils";
 import { KeyBackupInfo } from "../../../src/crypto-api";
@@ -473,21 +474,23 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
             expect(request.phase).toEqual(VerificationPhase.Ready);
 
             // we should now have QR data we can display
-            const qrCodeBuffer = (await request.generateQRCode())!;
-            expect(qrCodeBuffer).toBeTruthy();
+            const rawQrCodeBuffer = (await request.generateQRCode())!;
+            expect(rawQrCodeBuffer).toBeTruthy();
+            const qrCodeBuffer = new Uint8Array(rawQrCodeBuffer);
 
+            const textDecoder = new TextDecoder();
             // https://spec.matrix.org/v1.7/client-server-api/#qr-code-format
-            expect(qrCodeBuffer.subarray(0, 6).toString("latin1")).toEqual("MATRIX");
-            expect(qrCodeBuffer.readUint8(6)).toEqual(0x02); // version
-            expect(qrCodeBuffer.readUint8(7)).toEqual(0x02); // mode
-            const txnIdLen = qrCodeBuffer.readUint16BE(8);
-            expect(qrCodeBuffer.subarray(10, 10 + txnIdLen).toString("utf-8")).toEqual(transactionId);
+            expect(textDecoder.decode(qrCodeBuffer.slice(0, 6))).toEqual("MATRIX");
+            expect(qrCodeBuffer[6]).toEqual(0x02); // version
+            expect(qrCodeBuffer[7]).toEqual(0x02); // mode
+            const txnIdLen = (qrCodeBuffer[8] << 8) + qrCodeBuffer[9];
+            expect(textDecoder.decode(qrCodeBuffer.slice(10, 10 + txnIdLen))).toEqual(transactionId);
             // Alice's device's public key comes next, but we have nothing to do with it here.
-            // const aliceDevicePubKey = qrCodeBuffer.subarray(10 + txnIdLen, 32 + 10 + txnIdLen);
-            expect(qrCodeBuffer.subarray(42 + txnIdLen, 32 + 42 + txnIdLen)).toEqual(
-                Buffer.from(MASTER_CROSS_SIGNING_PUBLIC_KEY_BASE64, "base64"),
+            // const aliceDevicePubKey = qrCodeBuffer.slice(10 + txnIdLen, 32 + 10 + txnIdLen);
+            expect(encodeUnpaddedBase64(qrCodeBuffer.slice(42 + txnIdLen, 32 + 42 + txnIdLen))).toEqual(
+                MASTER_CROSS_SIGNING_PUBLIC_KEY_BASE64,
             );
-            const sharedSecret = qrCodeBuffer.subarray(74 + txnIdLen);
+            const sharedSecret = qrCodeBuffer.slice(74 + txnIdLen);
 
             // we should still be "Ready" and have no verifier
             expect(request.phase).toEqual(VerificationPhase.Ready);
@@ -805,7 +808,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
             // we should now have QR data we can display
             const qrCodeBuffer = (await request.generateQRCode())!;
             expect(qrCodeBuffer).toBeTruthy();
-            const sharedSecret = qrCodeBuffer.subarray(74 + transactionId.length);
+            const sharedSecret = qrCodeBuffer.slice(74 + transactionId.length);
 
             // the dummy device "scans" the displayed QR code and acknowledges it with a "m.key.verification.start"
             returnToDeviceMessageFromSync(buildReciprocateStartMessage(transactionId, sharedSecret));
@@ -990,6 +993,18 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
             aliceClient.setGlobalErrorOnUnknownDevices(false);
             syncResponder.sendOrQueueSyncResponse(getSyncResponse([BOB_TEST_USER_ID]));
             await syncPromise(aliceClient);
+
+            // Rust crypto requires the sender's device keys before it accepts a
+            // verification request.
+            if (backend === "rust-sdk") {
+                const crypto = aliceClient.getCrypto()!;
+
+                const bobDeviceKeys = getTestOlmAccountKeys(testOlmAccount, BOB_TEST_USER_ID, "BobDevice");
+                e2eKeyResponder.addDeviceKeys(bobDeviceKeys);
+                syncResponder.sendOrQueueSyncResponse({ device_lists: { changed: [BOB_TEST_USER_ID] } });
+                await syncPromise(aliceClient);
+                await crypto.getUserDeviceInfo([BOB_TEST_USER_ID]);
+            }
         });
 
         /**
@@ -1627,7 +1642,7 @@ function buildReadyMessage(
 }
 
 /** build an m.key.verification.start to-device message suitable for the m.reciprocate.v1 flow, originating from the dummy device */
-function buildReciprocateStartMessage(transactionId: string, sharedSecret: Uint8Array) {
+function buildReciprocateStartMessage(transactionId: string, sharedSecret: ArrayBuffer) {
     return {
         type: "m.key.verification.start",
         content: {
@@ -1723,7 +1738,7 @@ function buildQRCode(
     key2Base64: string,
     sharedSecret: string,
     mode = 0x02,
-): Uint8Array {
+): Uint8ClampedArray {
     // https://spec.matrix.org/v1.7/client-server-api/#qr-code-format
 
     const qrCodeBuffer = Buffer.alloc(150); // oversize
@@ -1739,5 +1754,5 @@ function buildQRCode(
     idx += qrCodeBuffer.write(sharedSecret, idx);
 
     // truncate to the right length
-    return qrCodeBuffer.subarray(0, idx);
+    return new Uint8ClampedArray(qrCodeBuffer.subarray(0, idx));
 }

spec/integ/devicelist-integ.spec.ts

@@ -77,7 +77,7 @@ describe("DeviceList management:", function () {
 
     async function createTestClient() {
         const testClient = new TestClient("@alice:localhost", "xzcvb", "akjgkrgjs", sessionStoreBackend);
-        await testClient.client.initCrypto();
+        await testClient.client.initLegacyCrypto();
         return testClient;
     }
 

spec/integ/matrix-client-event-timeline.spec.ts

@@ -1144,7 +1144,7 @@ describe("MatrixClient event timelines", function () {
 
         const prom = emitPromise(room, ThreadEvent.Update);
         // Assume we're seeing the reply while loading backlog
-        await room.addLiveEvents([THREAD_REPLY2]);
+        await room.addLiveEvents([THREAD_REPLY2], { addToState: false });
         httpBackend
             .when(
                 "GET",
@@ -1155,7 +1155,7 @@ describe("MatrixClient event timelines", function () {
             });
         await flushHttp(prom);
         // but while loading the metadata, a new reply has arrived
-        await room.addLiveEvents([THREAD_REPLY3]);
+        await room.addLiveEvents([THREAD_REPLY3], { addToState: false });
         const thread = room.getThread(THREAD_ROOT_UPDATED.event_id!)!;
         // then the events should still be all in the right order
         expect(thread.events.map((it) => it.getId())).toEqual([
@@ -1247,7 +1247,7 @@ describe("MatrixClient event timelines", function () {
 
         const prom = emitPromise(room, ThreadEvent.Update);
         // Assume we're seeing the reply while loading backlog
-        await room.addLiveEvents([THREAD_REPLY2]);
+        await room.addLiveEvents([THREAD_REPLY2], { addToState: false });
         httpBackend
             .when(
                 "GET",
@@ -1263,7 +1263,7 @@ describe("MatrixClient event timelines", function () {
             });
         await flushHttp(prom);
         // but while loading the metadata, a new reply has arrived
-        await room.addLiveEvents([THREAD_REPLY3]);
+        await room.addLiveEvents([THREAD_REPLY3], { addToState: false });
         const thread = room.getThread(THREAD_ROOT_UPDATED.event_id!)!;
         // then the events should still be all in the right order
         expect(thread.events.map((it) => it.getId())).toEqual([
@@ -1560,7 +1560,7 @@ describe("MatrixClient event timelines", function () {
                 thread.initialEventsFetched = true;
                 const prom = emitPromise(room, ThreadEvent.NewReply);
                 respondToEvent(THREAD_ROOT_UPDATED);
-                await room.addLiveEvents([THREAD_REPLY2]);
+                await room.addLiveEvents([THREAD_REPLY2], { addToState: false });
                 await httpBackend.flushAllExpected();
                 await prom;
                 expect(thread.length).toBe(2);
@@ -1685,7 +1685,7 @@ describe("MatrixClient event timelines", function () {
                 thread.initialEventsFetched = true;
                 const prom = emitPromise(room, ThreadEvent.Update);
                 respondToEvent(THREAD_ROOT_UPDATED);
-                await room.addLiveEvents([THREAD_REPLY_REACTION]);
+                await room.addLiveEvents([THREAD_REPLY_REACTION], { addToState: false });
                 await httpBackend.flushAllExpected();
                 await prom;
                 expect(thread.length).toBe(1); // reactions don't count towards the length of a thread

spec/integ/matrix-client-methods.spec.ts

@@ -168,14 +168,17 @@ describe("MatrixClient", function () {
                     type: "test",
                     content: {},
                 });
-            room.addLiveEvents([
-                utils.mkMembership({
-                    user: userId,
-                    room: roomId,
-                    mship: KnownMembership.Join,
-                    event: true,
-                }),
-            ]);
+            room.addLiveEvents(
+                [
+                    utils.mkMembership({
+                        user: userId,
+                        room: roomId,
+                        mship: KnownMembership.Join,
+                        event: true,
+                    }),
+                ],
+                { addToState: true },
+            );
             httpBackend.verifyNoOutstandingRequests();
             store.storeRoom(room);
 
@@ -188,14 +191,17 @@ describe("MatrixClient", function () {
             const roomId = "!roomId:server";
             const roomAlias = "#my-fancy-room:server";
             const room = new Room(roomId, client, userId);
-            room.addLiveEvents([
-                utils.mkMembership({
-                    user: userId,
-                    room: roomId,
-                    mship: KnownMembership.Join,
-                    event: true,
-                }),
-            ]);
+            room.addLiveEvents(
+                [
+                    utils.mkMembership({
+                        user: userId,
+                        room: roomId,
+                        mship: KnownMembership.Join,
+                        event: true,
+                    }),
+                ],
+                { addToState: true },
+            );
             store.storeRoom(room);
 
             // The method makes a request to resolve the alias
@@ -275,14 +281,17 @@ describe("MatrixClient", function () {
                     content: {},
                 });
 
-            room.addLiveEvents([
-                utils.mkMembership({
-                    user: userId,
-                    room: roomId,
-                    mship: KnownMembership.Knock,
-                    event: true,
-                }),
-            ]);
+            room.addLiveEvents(
+                [
+                    utils.mkMembership({
+                        user: userId,
+                        room: roomId,
+                        mship: KnownMembership.Knock,
+                        event: true,
+                    }),
+                ],
+                { addToState: true },
+            );
 
             httpBackend.verifyNoOutstandingRequests();
             store.storeRoom(room);
@@ -641,9 +650,9 @@ describe("MatrixClient", function () {
         }
 
         beforeEach(function () {
-            // running initCrypto should trigger a key upload
+            // running initLegacyCrypto should trigger a key upload
             httpBackend.when("POST", "/keys/upload").respond(200, {});
-            return Promise.all([client.initCrypto(), httpBackend.flush("/keys/upload", 1)]);
+            return Promise.all([client.initLegacyCrypto(), httpBackend.flush("/keys/upload", 1)]);
         });
 
         afterEach(() => {
@@ -1906,6 +1915,28 @@ describe("MatrixClient", function () {
             return prom;
         });
     });
+
+    describe("getDomain", () => {
+        it("should return null if no userId is set", () => {
+            const client = new MatrixClient({ baseUrl: "http://localhost" });
+            expect(client.getDomain()).toBeNull();
+        });
+
+        it("should return the domain of the userId", () => {
+            expect(client.getDomain()).toBe("localhost");
+        });
+    });
+
+    describe("getUserIdLocalpart", () => {
+        it("should return null if no userId is set", () => {
+            const client = new MatrixClient({ baseUrl: "http://localhost" });
+            expect(client.getUserIdLocalpart()).toBeNull();
+        });
+
+        it("should return the localpart of the userId", () => {
+            expect(client.getUserIdLocalpart()).toBe("alice");
+        });
+    });
 });
 
 function withThreadId(event: MatrixEvent, newThreadId: string): MatrixEvent {

spec/integ/matrix-client-syncing.spec.ts

@@ -112,7 +112,7 @@ describe("MatrixClient syncing", () => {
         });
 
         it("should emit RoomEvent.MyMembership for invite->leave->invite cycles", async () => {
-            await client!.initCrypto();
+            await client!.initLegacyCrypto();
 
             const roomId = "!cycles:example.org";
 
@@ -227,7 +227,7 @@ describe("MatrixClient syncing", () => {
         });
 
         it("should emit RoomEvent.MyMembership for knock->leave->knock cycles", async () => {
-            await client!.initCrypto();
+            await client!.initLegacyCrypto();
 
             const roomId = "!cycles:example.org";
 
@@ -556,7 +556,7 @@ describe("MatrixClient syncing", () => {
         });
 
         it("should resolve incoming invites from /sync", () => {
-            syncData.rooms.join[roomOne].state.events.push(
+            syncData.rooms.join[roomOne].state!.events.push(
                 utils.mkMembership({
                     room: roomOne,
                     mship: KnownMembership.Invite,
@@ -589,7 +589,7 @@ describe("MatrixClient syncing", () => {
                     name: "The Ghost",
                 }) as IMinimalEvent,
             ];
-            syncData.rooms.join[roomOne].state.events.push(
+            syncData.rooms.join[roomOne].state!.events.push(
                 utils.mkMembership({
                     room: roomOne,
                     mship: KnownMembership.Invite,
@@ -617,7 +617,7 @@ describe("MatrixClient syncing", () => {
                     name: "The Ghost",
                 }) as IMinimalEvent,
             ];
-            syncData.rooms.join[roomOne].state.events.push(
+            syncData.rooms.join[roomOne].state!.events.push(
                 utils.mkMembership({
                     room: roomOne,
                     mship: KnownMembership.Invite,
@@ -644,7 +644,7 @@ describe("MatrixClient syncing", () => {
         });
 
         it("should no-op if resolveInvitesToProfiles is not set", () => {
-            syncData.rooms.join[roomOne].state.events.push(
+            syncData.rooms.join[roomOne].state!.events.push(
                 utils.mkMembership({
                     room: roomOne,
                     mship: KnownMembership.Invite,
@@ -1373,6 +1373,114 @@ describe("MatrixClient syncing", () => {
                 expect(stateEventEmitCount).toEqual(2);
             });
         });
+
+        describe("msc4222", () => {
+            const roomOneSyncOne = {
+                "timeline": {
+                    events: [
+                        utils.mkMessage({
+                            room: roomOne,
+                            user: otherUserId,
+                            msg: "hello",
+                        }),
+                    ],
+                },
+                "org.matrix.msc4222.state_after": {
+                    events: [
+                        utils.mkEvent({
+                            type: "m.room.name",
+                            room: roomOne,
+                            user: otherUserId,
+                            content: {
+                                name: "Initial room name",
+                            },
+                        }),
+                        utils.mkMembership({
+                            room: roomOne,
+                            mship: KnownMembership.Join,
+                            user: otherUserId,
+                        }),
+                        utils.mkMembership({
+                            room: roomOne,
+                            mship: KnownMembership.Join,
+                            user: selfUserId,
+                        }),
+                        utils.mkEvent({
+                            type: "m.room.create",
+                            room: roomOne,
+                            user: selfUserId,
+                            content: {},
+                        }),
+                    ],
+                },
+            };
+            const roomOneSyncTwo = {
+                "org.matrix.msc4222.state_after": {
+                    events: [
+                        utils.mkEvent({
+                            type: "m.room.topic",
+                            room: roomOne,
+                            user: selfUserId,
+                            content: { topic: "A new room topic" },
+                        }),
+                    ],
+                },
+                "state": {
+                    events: [
+                        utils.mkEvent({
+                            type: "m.room.name",
+                            room: roomOne,
+                            user: selfUserId,
+                            content: { name: "A new room name" },
+                        }),
+                    ],
+                },
+            };
+
+            it("should ignore state events in timeline when state_after is present", async () => {
+                httpBackend!.when("GET", "/sync").respond(200, {
+                    rooms: {
+                        join: { [roomOne]: roomOneSyncOne },
+                    },
+                });
+                httpBackend!.when("GET", "/sync").respond(200, {
+                    rooms: {
+                        join: { [roomOne]: roomOneSyncTwo },
+                    },
+                });
+
+                client!.startClient();
+                return Promise.all([httpBackend!.flushAllExpected(), awaitSyncEvent(2)]).then(() => {
+                    const room = client!.getRoom(roomOne)!;
+                    expect(room.name).toEqual("Initial room name");
+                    expect(room.currentState.getStateEvents("m.room.topic", "")?.getContent().topic).toBe(
+                        "A new room topic",
+                    );
+                });
+            });
+
+            it("should respect state events in state_after for left rooms", async () => {
+                httpBackend!.when("GET", "/sync").respond(200, {
+                    rooms: {
+                        join: { [roomOne]: roomOneSyncOne },
+                    },
+                });
+                httpBackend!.when("GET", "/sync").respond(200, {
+                    rooms: {
+                        leave: { [roomOne]: roomOneSyncTwo },
+                    },
+                });
+
+                client!.startClient();
+                return Promise.all([httpBackend!.flushAllExpected(), awaitSyncEvent(2)]).then(() => {
+                    const room = client!.getRoom(roomOne)!;
+                    expect(room.name).toEqual("Initial room name");
+                    expect(room.currentState.getStateEvents("m.room.topic", "")?.getContent().topic).toBe(
+                        "A new room topic",
+                    );
+                });
+            });
+        });
     });
 
     describe("timeline", () => {
@@ -2274,6 +2382,57 @@ describe("MatrixClient syncing", () => {
                 }),
             ]);
         });
+
+        describe("msc4222", () => {
+            it("should respect state events in state_after for left rooms", async () => {
+                httpBackend!.when("POST", "/filter").respond(200, {
+                    filter_id: "another_id",
+                });
+
+                httpBackend!.when("GET", "/sync").respond(200, {
+                    rooms: {
+                        leave: {
+                            [roomOne]: {
+                                "org.matrix.msc4222.state_after": {
+                                    events: [
+                                        utils.mkEvent({
+                                            type: "m.room.topic",
+                                            room: roomOne,
+                                            user: selfUserId,
+                                            content: { topic: "A new room topic" },
+                                        }),
+                                    ],
+                                },
+                                "state": {
+                                    events: [
+                                        utils.mkEvent({
+                                            type: "m.room.name",
+                                            room: roomOne,
+                                            user: selfUserId,
+                                            content: { name: "A new room name" },
+                                        }),
+                                    ],
+                                },
+                            },
+                        },
+                    },
+                });
+
+                const [[room]] = await Promise.all([
+                    client!.syncLeftRooms(),
+
+                    // first flush the filter request; this will make syncLeftRooms make its /sync call
+                    httpBackend!.flush("/filter").then(() => {
+                        return httpBackend!.flushAllExpected();
+                    }),
+                ]);
+
+                expect(room.name).toEqual("Empty room");
+                expect(room.currentState.getStateEvents("m.room.topic", "")?.getContent().topic).toBe(
+                    "A new room topic",
+                );
+            });
+        });
     });
 
     describe("peek", () => {
@@ -2414,7 +2573,7 @@ describe("MatrixClient syncing (IndexedDB version)", () => {
         idbHttpBackend.when("GET", "/pushrules/").respond(200, {});
         idbHttpBackend.when("POST", "/filter").respond(200, { filter_id: "a filter id" });
 
-        await idbClient.initCrypto();
+        await idbClient.initLegacyCrypto();
 
         const roomId = "!invite:example.org";
 

spec/integ/matrix-client-unread-notifications.spec.ts

@@ -128,7 +128,7 @@ describe("MatrixClient syncing", () => {
 
         const thread = mkThread({ room, client: client!, authorId: selfUserId, participantUserIds: [selfUserId] });
         const threadReply = thread.events.at(-1)!;
-        await room.addLiveEvents([thread.rootEvent]);
+        await room.addLiveEvents([thread.rootEvent], { addToState: false });
 
         // Initialize read receipt datastructure before testing the reaction
         room.addReceiptToStructure(thread.rootEvent.getId()!, ReceiptType.Read, selfUserId, { ts: 1 }, false);

spec/integ/sliding-sync-sdk.spec.ts

@@ -119,7 +119,7 @@ describe("SlidingSyncSdk", () => {
         mockSlidingSync = mockifySlidingSync(new SlidingSync("", new Map(), {}, client, 0));
         if (testOpts.withCrypto) {
             httpBackend!.when("GET", "/room_keys/version").respond(404, {});
-            await client!.initCrypto();
+            await client!.initLegacyCrypto();
             syncOpts.cryptoCallbacks = syncOpts.crypto = client!.crypto;
         }
         httpBackend!.when("GET", "/_matrix/client/v3/pushrules").respond(200, {});
@@ -601,13 +601,13 @@ describe("SlidingSyncSdk", () => {
             mockSlidingSync!.emit(SlidingSyncEvent.RoomData, roomId, {
                 initial: true,
                 name: "Room with Invite",
-                required_state: [],
-                timeline: [
+                required_state: [
                     mkOwnStateEvent(EventType.RoomCreate, {}, ""),
                     mkOwnStateEvent(EventType.RoomMember, { membership: KnownMembership.Join }, selfUserId),
                     mkOwnStateEvent(EventType.RoomPowerLevels, { users: { [selfUserId]: 100 } }, ""),
                     mkOwnStateEvent(EventType.RoomMember, { membership: KnownMembership.Invite }, invitee),
                 ],
+                timeline: [],
             });
             await httpBackend!.flush("/profile", 1, 1000);
             await emitPromise(client!, RoomMemberEvent.Name);
@@ -921,13 +921,12 @@ describe("SlidingSyncSdk", () => {
             const roomId = "!room:id";
             mockSlidingSync!.emit(SlidingSyncEvent.RoomData, roomId, {
                 name: "Room with typing",
-                required_state: [],
-                timeline: [
+                required_state: [
                     mkOwnStateEvent(EventType.RoomCreate, {}, ""),
                     mkOwnStateEvent(EventType.RoomMember, { membership: KnownMembership.Join }, selfUserId),
                     mkOwnStateEvent(EventType.RoomPowerLevels, { users: { [selfUserId]: 100 } }, ""),
-                    mkOwnEvent(EventType.RoomMessage, { body: "hello" }),
                 ],
+                timeline: [mkOwnEvent(EventType.RoomMessage, { body: "hello" })],
                 initial: true,
             });
             await emitPromise(client!, ClientEvent.Room);
@@ -962,13 +961,12 @@ describe("SlidingSyncSdk", () => {
             const roomId = "!room:id";
             mockSlidingSync!.emit(SlidingSyncEvent.RoomData, roomId, {
                 name: "Room with typing",
-                required_state: [],
-                timeline: [
+                required_state: [
                     mkOwnStateEvent(EventType.RoomCreate, {}, ""),
                     mkOwnStateEvent(EventType.RoomMember, { membership: KnownMembership.Join }, selfUserId),
                     mkOwnStateEvent(EventType.RoomPowerLevels, { users: { [selfUserId]: 100 } }, ""),
-                    mkOwnEvent(EventType.RoomMessage, { body: "hello" }),
                 ],
+                timeline: [mkOwnEvent(EventType.RoomMessage, { body: "hello" })],
                 initial: true,
             });
             const room = client!.getRoom(roomId)!;

spec/test-utils/test-utils.ts

@@ -86,7 +86,7 @@ export function getSyncResponse(roomMembers: string[], roomId = TEST_ROOM_ID): I
     };
 
     for (let i = 0; i < roomMembers.length; i++) {
-        roomResponse.state.events.push(
+        roomResponse.state!.events.push(
             mkMembershipCustom({
                 membership: KnownMembership.Join,
                 sender: roomMembers[i],
@@ -561,7 +561,7 @@ export type InitCrypto = (_: MatrixClient) => Promise<void>;
 
 CRYPTO_BACKENDS["rust-sdk"] = (client: MatrixClient) => client.initRustCrypto();
 if (globalThis.Olm) {
-    CRYPTO_BACKENDS["libolm"] = (client: MatrixClient) => client.initCrypto();
+    CRYPTO_BACKENDS["libolm"] = (client: MatrixClient) => client.initLegacyCrypto();
 }
 
 export const emitPromise = (e: EventEmitter, k: string): Promise<any> => new Promise((r) => e.once(k, r));

spec/test-utils/thread.ts

@@ -178,6 +178,6 @@ export const populateThread = ({
 }: MakeThreadProps): MakeThreadResult => {
     const ret = mkThread({ room, client, authorId, participantUserIds, length, ts });
     ret.thread.initialEventsFetched = true;
-    room.addLiveEvents(ret.events);
+    room.addLiveEvents(ret.events, { addToState: false });
     return ret;
 };

spec/test-utils/webrtc.ts

@@ -481,6 +481,9 @@ export class MockCallMatrixClient extends TypedEventEmitter<EmittedEvents, Emitt
     public getUserId(): string {
         return this.userId;
     }
+    public getSafeUserId(): string {
+        return this.userId;
+    }
 
     public getDeviceId(): string {
         return this.deviceId;

spec/unit/base64.spec.ts

@@ -15,34 +15,10 @@ limitations under the License.
 */
 
 import { TextEncoder, TextDecoder } from "util";
-import NodeBuffer from "node:buffer";
 
 import { decodeBase64, encodeBase64, encodeUnpaddedBase64, encodeUnpaddedBase64Url } from "../../src/base64";
 
-describe.each(["browser", "node"])("Base64 encoding (%s)", (env) => {
-    let origBuffer = Buffer;
-
-    beforeAll(() => {
-        if (env === "browser") {
-            origBuffer = Buffer;
-            // @ts-ignore
-            // eslint-disable-next-line no-global-assign
-            Buffer = undefined;
-
-            globalThis.atob = NodeBuffer.atob;
-            globalThis.btoa = NodeBuffer.btoa;
-        }
-    });
-
-    afterAll(() => {
-        // eslint-disable-next-line no-global-assign
-        Buffer = origBuffer;
-        // @ts-ignore
-        globalThis.atob = undefined;
-        // @ts-ignore
-        globalThis.btoa = undefined;
-    });
-
+describe("Base64 encoding", () => {
     it("Should decode properly encoded data", () => {
         const decoded = new TextDecoder().decode(decodeBase64("ZW5jb2RpbmcgaGVsbG8gd29ybGQ="));
 

spec/unit/crypto.spec.ts

@@ -119,7 +119,7 @@ describe("Crypto", function () {
 
     it("getVersion() should return the current version of the olm library", async () => {
         const client = new TestClient("@alice:example.com", "deviceid").client;
-        await client.initCrypto();
+        await client.initLegacyCrypto();
 
         const olmVersionTuple = Crypto.getOlmVersion();
         expect(client.getCrypto()?.getVersion()).toBe(
@@ -130,7 +130,7 @@ describe("Crypto", function () {
     describe("encrypted events", function () {
         it("provides encryption information for events from unverified senders", async function () {
             const client = new TestClient("@alice:example.com", "deviceid").client;
-            await client.initCrypto();
+            await client.initLegacyCrypto();
 
             // unencrypted event
             const event = {
@@ -210,7 +210,7 @@ describe("Crypto", function () {
             let client: MatrixClient;
             beforeEach(async () => {
                 client = new TestClient("@alice:example.com", "deviceid").client;
-                await client.initCrypto();
+                await client.initLegacyCrypto();
 
                 // mock out the verification check
                 client.crypto!.checkUserTrust = (userId) => new UserTrustLevel(true, false, false);
@@ -306,7 +306,7 @@ describe("Crypto", function () {
 
         it("doesn't throw an error when attempting to decrypt a redacted event", async () => {
             const client = new TestClient("@alice:example.com", "deviceid").client;
-            await client.initCrypto();
+            await client.initLegacyCrypto();
 
             const event = new MatrixEvent({
                 content: {},
@@ -439,10 +439,10 @@ describe("Crypto", function () {
             secondAliceClient = new TestClient("@alice:example.com", "secondAliceDevice").client;
             bobClient = new TestClient("@bob:example.com", "bobdevice").client;
             claraClient = new TestClient("@clara:example.com", "claradevice").client;
-            await aliceClient.initCrypto();
-            await secondAliceClient.initCrypto();
-            await bobClient.initCrypto();
-            await claraClient.initCrypto();
+            await aliceClient.initLegacyCrypto();
+            await secondAliceClient.initLegacyCrypto();
+            await bobClient.initLegacyCrypto();
+            await claraClient.initLegacyCrypto();
         });
 
         afterEach(async function () {
@@ -1111,7 +1111,7 @@ describe("Crypto", function () {
             jest.spyOn(logger, "debug").mockImplementation(() => {});
             jest.setTimeout(10000);
             const client = new TestClient("@a:example.com", "dev").client;
-            await client.initCrypto();
+            await client.initLegacyCrypto();
             client.crypto!.isCrossSigningReady = async () => false;
             client.crypto!.baseApis.uploadDeviceSigningKeys = jest.fn().mockResolvedValue(null);
             client.crypto!.baseApis.setAccountData = jest.fn().mockResolvedValue(null);
@@ -1147,9 +1147,9 @@ describe("Crypto", function () {
 
             client = new TestClient("@alice:example.org", "aliceweb");
 
-            // running initCrypto should trigger a key upload
+            // running initLegacyCrypto should trigger a key upload
             client.httpBackend.when("POST", "/keys/upload").respond(200, {});
-            await Promise.all([client.client.initCrypto(), client.httpBackend.flush("/keys/upload", 1)]);
+            await Promise.all([client.client.initLegacyCrypto(), client.httpBackend.flush("/keys/upload", 1)]);
 
             encryptedPayload = {
                 algorithm: "m.olm.v1.curve25519-aes-sha2",
@@ -1264,9 +1264,9 @@ describe("Crypto", function () {
 
             client = new TestClient("@alice:example.org", "aliceweb");
 
-            // running initCrypto should trigger a key upload
+            // running initLegacyCrypto should trigger a key upload
             client.httpBackend.when("POST", "/keys/upload").respond(200, {});
-            await Promise.all([client.client.initCrypto(), client.httpBackend.flush("/keys/upload", 1)]);
+            await Promise.all([client.client.initLegacyCrypto(), client.httpBackend.flush("/keys/upload", 1)]);
 
             encryptedPayload = {
                 algorithm: "m.olm.v1.curve25519-aes-sha2",
@@ -1362,7 +1362,7 @@ describe("Crypto", function () {
 
         beforeEach(async () => {
             client = new TestClient("@alice:example.org", "aliceweb");
-            await client.client.initCrypto();
+            await client.client.initLegacyCrypto();
         });
 
         afterEach(async () => {
@@ -1388,7 +1388,7 @@ describe("Crypto", function () {
 
         beforeEach(async () => {
             client = new TestClient("@alice:example.org", "aliceweb");
-            await client.client.initCrypto();
+            await client.client.initLegacyCrypto();
         });
 
         afterEach(async () => {
@@ -1414,7 +1414,7 @@ describe("Crypto", function () {
 
         beforeEach(async () => {
             client = new TestClient("@alice:example.org", "aliceweb");
-            await client.client.initCrypto();
+            await client.client.initLegacyCrypto();
         });
 
         afterEach(async function () {

spec/unit/crypto/algorithms/megolm.spec.ts

@@ -610,7 +610,11 @@ describe("MegolmDecryption", function () {
         const aliceClient = new TestClient("@alice:example.com", "alicedevice").client;
         const bobClient1 = new TestClient("@bob:example.com", "bobdevice1").client;
         const bobClient2 = new TestClient("@bob:example.com", "bobdevice2").client;
-        await Promise.all([aliceClient.initCrypto(), bobClient1.initCrypto(), bobClient2.initCrypto()]);
+        await Promise.all([
+            aliceClient.initLegacyCrypto(),
+            bobClient1.initLegacyCrypto(),
+            bobClient2.initLegacyCrypto(),
+        ]);
         const aliceDevice = aliceClient.crypto!.olmDevice;
         const bobDevice1 = bobClient1.crypto!.olmDevice;
         const bobDevice2 = bobClient2.crypto!.olmDevice;
@@ -704,7 +708,7 @@ describe("MegolmDecryption", function () {
     it("does not block unverified devices when sending verification events", async function () {
         const aliceClient = new TestClient("@alice:example.com", "alicedevice").client;
         const bobClient = new TestClient("@bob:example.com", "bobdevice").client;
-        await Promise.all([aliceClient.initCrypto(), bobClient.initCrypto()]);
+        await Promise.all([aliceClient.initLegacyCrypto(), bobClient.initLegacyCrypto()]);
         const bobDevice = bobClient.crypto!.olmDevice;
 
         const encryptionCfg = {
@@ -789,7 +793,7 @@ describe("MegolmDecryption", function () {
     it("notifies devices when unable to create olm session", async function () {
         const aliceClient = new TestClient("@alice:example.com", "alicedevice").client;
         const bobClient = new TestClient("@bob:example.com", "bobdevice").client;
-        await Promise.all([aliceClient.initCrypto(), bobClient.initCrypto()]);
+        await Promise.all([aliceClient.initLegacyCrypto(), bobClient.initLegacyCrypto()]);
         const aliceDevice = aliceClient.crypto!.olmDevice;
         const bobDevice = bobClient.crypto!.olmDevice;
 
@@ -873,7 +877,7 @@ describe("MegolmDecryption", function () {
     it("throws an error describing why it doesn't have a key", async function () {
         const aliceClient = new TestClient("@alice:example.com", "alicedevice").client;
         const bobClient = new TestClient("@bob:example.com", "bobdevice").client;
-        await Promise.all([aliceClient.initCrypto(), bobClient.initCrypto()]);
+        await Promise.all([aliceClient.initLegacyCrypto(), bobClient.initLegacyCrypto()]);
         const bobDevice = bobClient.crypto!.olmDevice;
 
         const aliceEventEmitter = new TypedEventEmitter<ClientEvent.ToDeviceEvent, any>();
@@ -955,7 +959,7 @@ describe("MegolmDecryption", function () {
     it("throws an error describing the lack of an olm session", async function () {
         const aliceClient = new TestClient("@alice:example.com", "alicedevice").client;
         const bobClient = new TestClient("@bob:example.com", "bobdevice").client;
-        await Promise.all([aliceClient.initCrypto(), bobClient.initCrypto()]);
+        await Promise.all([aliceClient.initLegacyCrypto(), bobClient.initLegacyCrypto()]);
 
         const aliceEventEmitter = new TypedEventEmitter<ClientEvent.ToDeviceEvent, any>();
         aliceClient.crypto!.registerEventHandlers(aliceEventEmitter);
@@ -1051,7 +1055,7 @@ describe("MegolmDecryption", function () {
     it("throws an error to indicate a wedged olm session", async function () {
         const aliceClient = new TestClient("@alice:example.com", "alicedevice").client;
         const bobClient = new TestClient("@bob:example.com", "bobdevice").client;
-        await Promise.all([aliceClient.initCrypto(), bobClient.initCrypto()]);
+        await Promise.all([aliceClient.initLegacyCrypto(), bobClient.initLegacyCrypto()]);
         const aliceEventEmitter = new TypedEventEmitter<ClientEvent.ToDeviceEvent, any>();
         aliceClient.crypto!.registerEventHandlers(aliceEventEmitter);
 

spec/unit/crypto/backup.spec.ts

@@ -231,7 +231,7 @@ describe("MegolmBackup", function () {
 
         test("fail if given backup has no version", async () => {
             const client = makeTestClient(cryptoStore);
-            await client.initCrypto();
+            await client.initLegacyCrypto();
             const data = {
                 algorithm: olmlib.MEGOLM_BACKUP_ALGORITHM,
                 auth_data: {
@@ -314,7 +314,7 @@ describe("MegolmBackup", function () {
             megolmDecryption.olmlib = mockOlmLib;
 
             return client
-                .initCrypto()
+                .initLegacyCrypto()
                 .then(() => {
                     return cryptoStore.doTxn("readwrite", [IndexedDBCryptoStore.STORE_SESSIONS], (txn) => {
                         cryptoStore.addEndToEndInboundGroupSession(
@@ -391,7 +391,7 @@ describe("MegolmBackup", function () {
             megolmDecryption.olmlib = mockOlmLib;
 
             return client
-                .initCrypto()
+                .initLegacyCrypto()
                 .then(() => {
                     return client.crypto!.storeSessionBackupPrivateKey(new Uint8Array(32));
                 })
@@ -471,7 +471,7 @@ describe("MegolmBackup", function () {
             // @ts-ignore private field access
             megolmDecryption.olmlib = mockOlmLib;
 
-            await client.initCrypto();
+            await client.initLegacyCrypto();
             client.uploadDeviceSigningKeys = async function (e) {
                 return {};
             };
@@ -560,7 +560,7 @@ describe("MegolmBackup", function () {
             // @ts-ignore private field access
             megolmDecryption.olmlib = mockOlmLib;
 
-            await client.initCrypto();
+            await client.initLegacyCrypto();
             await cryptoStore.doTxn("readwrite", [IndexedDBCryptoStore.STORE_SESSIONS], (txn) => {
                 cryptoStore.addEndToEndInboundGroupSession(
                     "F0Q2NmyJNgUVj9DGsb4ZQt3aVxhVcUQhg7+gvW0oyKI",
@@ -636,7 +636,7 @@ describe("MegolmBackup", function () {
             // @ts-ignore private field access
             megolmDecryption.olmlib = mockOlmLib;
 
-            return client.initCrypto();
+            return client.initLegacyCrypto();
         });
 
         afterEach(function () {
@@ -773,11 +773,19 @@ describe("MegolmBackup", function () {
             // initialising the crypto library will trigger a key upload request, which we can stub out
             client.uploadKeysRequest = jest.fn();
 
-            await client.initCrypto();
+            await client.initLegacyCrypto();
 
             cryptoStore.countSessionsNeedingBackup = jest.fn().mockReturnValue(6);
             await expect(client.flagAllGroupSessionsForBackup()).resolves.toBe(6);
             client.stopClient();
         });
     });
+
+    describe("getKeyBackupInfo", () => {
+        it("should return throw an `Not implemented`", async () => {
+            const client = makeTestClient(cryptoStore);
+            await client.initLegacyCrypto();
+            await expect(client.getCrypto()?.getKeyBackupInfo()).rejects.toThrow("Not implemented");
+        });
+    });
 });

spec/unit/crypto/cross-signing.spec.ts

@@ -78,7 +78,7 @@ async function makeTestClient(
     const testClient = new TestClient(userInfo.userId, userInfo.deviceId, undefined, undefined, options);
     const client = testClient.client;
 
-    await client.initCrypto();
+    await client.initLegacyCrypto();
 
     return { client, httpBackend: testClient.httpBackend };
 }

spec/unit/crypto/dehydration.spec.ts

@@ -68,7 +68,7 @@ describe("Dehydration", () => {
             },
         });
 
-        await alice.client.initCrypto();
+        await alice.client.initLegacyCrypto();
 
         alice.httpBackend.when("GET", "/room_keys/version").respond(404, {
             errcode: "M_NOT_FOUND",

spec/unit/crypto/secrets.spec.ts

@@ -43,7 +43,7 @@ async function makeTestClient(
         return true;
     };
 
-    await client.initCrypto();
+    await client.initLegacyCrypto();
 
     // No need to download keys for these tests
     jest.spyOn(client.crypto!, "downloadKeys").mockResolvedValue(new Map());

spec/unit/crypto/verification/util.ts

@@ -119,7 +119,7 @@ export async function makeTestClients(
         clients.push(testClient);
     }
 
-    await Promise.all(clients.map((testClient) => testClient.client.initCrypto()));
+    await Promise.all(clients.map((testClient) => testClient.client.initLegacyCrypto()));
 
     const destroy = () => {
         timeouts.forEach((t) => clearTimeout(t));

spec/unit/embedded.spec.ts

@@ -30,6 +30,7 @@ import {
     ITurnServer,
     IRoomEvent,
     IOpenIDCredentials,
+    ISendEventFromWidgetResponseData,
     WidgetApiResponseError,
 } from "matrix-widget-api";
 
@@ -40,6 +41,7 @@ import { ICapabilities, RoomWidgetClient } from "../../src/embedded";
 import { MatrixEvent } from "../../src/models/event";
 import { ToDeviceBatch } from "../../src/models/ToDeviceMessage";
 import { DeviceInfo } from "../../src/crypto/deviceinfo";
+import { sleep } from "../../src/utils";
 
 const testOIDCToken = {
     access_token: "12345678",
@@ -127,9 +129,16 @@ describe("RoomWidgetClient", () => {
     const makeClient = async (
         capabilities: ICapabilities,
         sendContentLoaded: boolean | undefined = undefined,
+        userId?: string,
     ): Promise<void> => {
         const baseUrl = "https://example.org";
-        client = createRoomWidgetClient(widgetApi, capabilities, "!1:example.org", { baseUrl }, sendContentLoaded);
+        client = createRoomWidgetClient(
+            widgetApi,
+            capabilities,
+            "!1:example.org",
+            { baseUrl, userId },
+            sendContentLoaded,
+        );
         expect(widgetApi.start).toHaveBeenCalled(); // needs to have been called early in order to not miss messages
         widgetApi.emit("ready");
         await client.startClient();
@@ -192,6 +201,142 @@ describe("RoomWidgetClient", () => {
                     .map((e) => e.getEffectiveEvent()),
             ).toEqual([event]);
         });
+        describe("local echos", () => {
+            const setupRemoteEcho = () => {
+                makeClient(
+                    {
+                        receiveEvent: ["org.matrix.rageshake_request"],
+                        sendEvent: ["org.matrix.rageshake_request"],
+                    },
+                    undefined,
+                    "@me:example.org",
+                );
+                expect(widgetApi.requestCapabilityForRoomTimeline).toHaveBeenCalledWith("!1:example.org");
+                expect(widgetApi.requestCapabilityToReceiveEvent).toHaveBeenCalledWith("org.matrix.rageshake_request");
+                const injectSpy = jest.spyOn((client as any).syncApi, "injectRoomEvents");
+                const widgetSendEmitter = new EventEmitter();
+                const widgetSendPromise = new Promise<void>((resolve) =>
+                    widgetSendEmitter.once("send", () => resolve()),
+                );
+                const resolveWidgetSend = () => widgetSendEmitter.emit("send");
+                widgetApi.sendRoomEvent.mockImplementation(
+                    async (eType, content, roomId): Promise<ISendEventFromWidgetResponseData> => {
+                        await widgetSendPromise;
+                        return { room_id: "!1:example.org", event_id: "event_id" };
+                    },
+                );
+                return { injectSpy, resolveWidgetSend };
+            };
+            const remoteEchoEvent = new CustomEvent(`action:${WidgetApiToWidgetAction.SendEvent}`, {
+                detail: {
+                    data: {
+                        type: "org.matrix.rageshake_request",
+
+                        room_id: "!1:example.org",
+                        event_id: "event_id",
+                        sender: "@me:example.org",
+                        state_key: "bar",
+                        content: { hello: "world" },
+                        unsigned: { transaction_id: "1234" },
+                    },
+                },
+                cancelable: true,
+            });
+            it("get response then local echo", async () => {
+                await sleep(600);
+                const { injectSpy, resolveWidgetSend } = await setupRemoteEcho();
+
+                // Begin by sending an event:
+                client.sendEvent("!1:example.org", "org.matrix.rageshake_request", { request_id: 12 }, "widgetTxId");
+                // we do not expect it to be send -- until we call `resolveWidgetSend`
+                expect(injectSpy).not.toHaveBeenCalled();
+
+                // We first get the response from the widget
+                resolveWidgetSend();
+                // We then get the remote echo from the widget
+                widgetApi.emit(`action:${WidgetApiToWidgetAction.SendEvent}`, remoteEchoEvent);
+
+                // gets emitted after the event got injected
+                await new Promise<void>((resolve) => client.once(ClientEvent.Event, () => resolve()));
+                expect(injectSpy).toHaveBeenCalled();
+
+                const call = injectSpy.mock.calls[0] as any;
+                const injectedEv = call[3][0];
+                expect(injectedEv.getType()).toBe("org.matrix.rageshake_request");
+                expect(injectedEv.getUnsigned().transaction_id).toBe("widgetTxId");
+            });
+
+            it("get local echo then response", async () => {
+                await sleep(600);
+                const { injectSpy, resolveWidgetSend } = await setupRemoteEcho();
+
+                // Begin by sending an event:
+                client.sendEvent("!1:example.org", "org.matrix.rageshake_request", { request_id: 12 }, "widgetTxId");
+                // we do not expect it to be send -- until we call `resolveWidgetSend`
+                expect(injectSpy).not.toHaveBeenCalled();
+
+                // We first get the remote echo from the widget
+                widgetApi.emit(`action:${WidgetApiToWidgetAction.SendEvent}`, remoteEchoEvent);
+                expect(injectSpy).not.toHaveBeenCalled();
+
+                // We then get the response from the widget
+                resolveWidgetSend();
+
+                // Gets emitted after the event got injected
+                await new Promise<void>((resolve) => client.once(ClientEvent.Event, () => resolve()));
+                expect(injectSpy).toHaveBeenCalled();
+
+                const call = injectSpy.mock.calls[0] as any;
+                const injectedEv = call[3][0];
+                expect(injectedEv.getType()).toBe("org.matrix.rageshake_request");
+                expect(injectedEv.getUnsigned().transaction_id).toBe("widgetTxId");
+            });
+            it("__ local echo then response", async () => {
+                await sleep(600);
+                const { injectSpy, resolveWidgetSend } = await setupRemoteEcho();
+
+                // Begin by sending an event:
+                client.sendEvent("!1:example.org", "org.matrix.rageshake_request", { request_id: 12 }, "widgetTxId");
+                // we do not expect it to be send -- until we call `resolveWidgetSend`
+                expect(injectSpy).not.toHaveBeenCalled();
+
+                // We first get the remote echo from the widget
+                widgetApi.emit(`action:${WidgetApiToWidgetAction.SendEvent}`, remoteEchoEvent);
+                const otherRemoteEcho = new CustomEvent(`action:${WidgetApiToWidgetAction.SendEvent}`, {
+                    detail: { data: { ...remoteEchoEvent.detail.data } },
+                });
+                otherRemoteEcho.detail.data.unsigned.transaction_id = "4567";
+                otherRemoteEcho.detail.data.event_id = "other_id";
+                widgetApi.emit(`action:${WidgetApiToWidgetAction.SendEvent}`, otherRemoteEcho);
+
+                // Simulate the wait time while the widget is waiting for a response
+                // after we already received the remote echo
+                await sleep(20);
+                // even after the wait we do not want any event to be injected.
+                // we do not know their event_id and cannot know if they are the remote echo
+                // where we need to update the txId because they are send by this client
+                expect(injectSpy).not.toHaveBeenCalled();
+                // We then get the response from the widget
+                resolveWidgetSend();
+
+                // Gets emitted after the event got injected
+                await new Promise<void>((resolve) => client.once(ClientEvent.Event, () => resolve()));
+                // Now we want both events to be injected since we know the txId - event_id match
+                expect(injectSpy).toHaveBeenCalled();
+
+                // it has been called with the event sent by ourselves
+                const call = injectSpy.mock.calls[0] as any;
+                const injectedEv = call[3][0];
+                expect(injectedEv.getType()).toBe("org.matrix.rageshake_request");
+                expect(injectedEv.getUnsigned().transaction_id).toBe("widgetTxId");
+
+                // It has been called by the event we blocked because of our send right afterwards
+                const call2 = injectSpy.mock.calls[1] as any;
+                const injectedEv2 = call2[3][0];
+                expect(injectedEv2.getType()).toBe("org.matrix.rageshake_request");
+                expect(injectedEv2.getUnsigned().transaction_id).toBe("4567");
+            });
+        });
 
         it("handles widget errors with generic error data", async () => {
             const error = new Error("failed to send");

spec/unit/event-mapper.spec.ts

@@ -74,7 +74,7 @@ describe("eventMapperFor", function () {
         const event = mapper(eventDefinition);
         expect(event).toBeInstanceOf(MatrixEvent);
 
-        room.addLiveEvents([event]);
+        room.addLiveEvents([event], { addToState: false });
         expect(room.findEventById(eventId)).toBe(event);
 
         const event2 = mapper(eventDefinition);
@@ -109,7 +109,7 @@ describe("eventMapperFor", function () {
 
         room.oldState.setStateEvents([event]);
         room.currentState.setStateEvents([event]);
-        room.addLiveEvents([event]);
+        room.addLiveEvents([event], { addToState: false });
         expect(room.findEventById(eventId)).toBe(event);
 
         const event2 = mapper(eventDefinition);

spec/unit/event-timeline-set.spec.ts

@@ -104,7 +104,7 @@ describe("EventTimelineSet", () => {
         it("Adds event to the live timeline in the timeline set", () => {
             const liveTimeline = eventTimelineSet.getLiveTimeline();
             expect(liveTimeline.getEvents().length).toStrictEqual(0);
-            eventTimelineSet.addLiveEvent(messageEvent);
+            eventTimelineSet.addLiveEvent(messageEvent, { addToState: false });
             expect(liveTimeline.getEvents().length).toStrictEqual(1);
         });
 
@@ -113,6 +113,7 @@ describe("EventTimelineSet", () => {
             expect(liveTimeline.getEvents().length).toStrictEqual(0);
             eventTimelineSet.addLiveEvent(messageEvent, {
                 duplicateStrategy: DuplicateStrategy.Replace,
+                addToState: false,
             });
             expect(liveTimeline.getEvents().length).toStrictEqual(1);
 
@@ -130,6 +131,7 @@ describe("EventTimelineSet", () => {
             // replace.
             eventTimelineSet.addLiveEvent(duplicateMessageEvent, {
                 duplicateStrategy: DuplicateStrategy.Replace,
+                addToState: false,
             });
 
             const eventsInLiveTimeline = liveTimeline.getEvents();
@@ -144,6 +146,7 @@ describe("EventTimelineSet", () => {
             expect(liveTimeline.getEvents().length).toStrictEqual(0);
             eventTimelineSet.addEventToTimeline(messageEvent, liveTimeline, {
                 toStartOfTimeline: true,
+                addToState: false,
             });
             expect(liveTimeline.getEvents().length).toStrictEqual(1);
         });
@@ -151,10 +154,17 @@ describe("EventTimelineSet", () => {
         it("Make sure legacy overload passing options directly as parameters still works", () => {
             const liveTimeline = eventTimelineSet.getLiveTimeline();
             expect(() => {
-                eventTimelineSet.addEventToTimeline(messageEvent, liveTimeline, true);
+                eventTimelineSet.addEventToTimeline(messageEvent, liveTimeline, {
+                    toStartOfTimeline: true,
+                    addToState: false,
+                });
             }).not.toThrow();
             expect(() => {
-                eventTimelineSet.addEventToTimeline(messageEvent, liveTimeline, true, false);
+                eventTimelineSet.addEventToTimeline(messageEvent, liveTimeline, {
+                    toStartOfTimeline: true,
+                    fromCache: false,
+                    addToState: false,
+                });
             }).not.toThrow();
         });
 
@@ -167,11 +177,13 @@ describe("EventTimelineSet", () => {
             expect(liveTimeline.getEvents().length).toStrictEqual(0);
             eventTimelineSet.addEventToTimeline(reactionEvent, liveTimeline, {
                 toStartOfTimeline: true,
+                addToState: false,
             });
             expect(liveTimeline.getEvents().length).toStrictEqual(0);
 
             eventTimelineSet.addEventToTimeline(messageEvent, liveTimeline, {
                 toStartOfTimeline: true,
+                addToState: false,
             });
             expect(liveTimeline.getEvents()).toHaveLength(1);
             const [event] = liveTimeline.getEvents();
@@ -202,6 +214,7 @@ describe("EventTimelineSet", () => {
             expect(() => {
                 eventTimelineSet.addEventToTimeline(messageEvent, liveTimeline2, {
                     toStartOfTimeline: true,
+                    addToState: false,
                 });
             }).toThrow();
         });
@@ -214,6 +227,7 @@ describe("EventTimelineSet", () => {
 
             eventTimelineSet.addEventToTimeline(threadedReplyEvent, liveTimeline, {
                 toStartOfTimeline: true,
+                addToState: false,
             });
             expect(liveTimeline.getEvents().length).toStrictEqual(0);
         });
@@ -232,6 +246,7 @@ describe("EventTimelineSet", () => {
 
             eventTimelineSetForThread.addEventToTimeline(normalMessage, liveTimeline, {
                 toStartOfTimeline: true,
+                addToState: false,
             });
             expect(liveTimeline.getEvents().length).toStrictEqual(0);
         });
@@ -248,6 +263,7 @@ describe("EventTimelineSet", () => {
                 expect(nonRoomEventTimeline.getEvents().length).toStrictEqual(0);
                 nonRoomEventTimelineSet.addEventToTimeline(messageEvent, nonRoomEventTimeline, {
                     toStartOfTimeline: true,
+                    addToState: false,
                 });
                 expect(nonRoomEventTimeline.getEvents().length).toStrictEqual(1);
             });
@@ -257,7 +273,7 @@ describe("EventTimelineSet", () => {
     describe("aggregateRelations", () => {
         describe("with unencrypted events", () => {
             beforeEach(() => {
-                eventTimelineSet.addEventsToTimeline([messageEvent, replyEvent], true, eventTimeline, "foo");
+                eventTimelineSet.addEventsToTimeline([messageEvent, replyEvent], true, false, eventTimeline, "foo");
             });
 
             itShouldReturnTheRelatedEvents();
@@ -279,7 +295,7 @@ describe("EventTimelineSet", () => {
                 replyEventShouldAttemptDecryptionSpy.mockReturnValue(true);
                 replyEventIsDecryptionFailureSpy = jest.spyOn(messageEvent, "isDecryptionFailure");
 
-                eventTimelineSet.addEventsToTimeline([messageEvent, replyEvent], true, eventTimeline, "foo");
+                eventTimelineSet.addEventsToTimeline([messageEvent, replyEvent], true, false, eventTimeline, "foo");
             });
 
             it("should not return the related events", () => {

spec/unit/event-timeline.spec.ts

@@ -98,7 +98,7 @@ describe("EventTimeline", function () {
             expect(function () {
                 timeline.initialiseState(state);
             }).not.toThrow();
-            timeline.addEvent(event, { toStartOfTimeline: false });
+            timeline.addEvent(event, { toStartOfTimeline: false, addToState: false });
             expect(function () {
                 timeline.initialiseState(state);
             }).toThrow();
@@ -182,9 +182,9 @@ describe("EventTimeline", function () {
         ];
 
         it("should be able to add events to the end", function () {
-            timeline.addEvent(events[0], { toStartOfTimeline: false });
+            timeline.addEvent(events[0], { toStartOfTimeline: false, addToState: false });
             const initialIndex = timeline.getBaseIndex();
-            timeline.addEvent(events[1], { toStartOfTimeline: false });
+            timeline.addEvent(events[1], { toStartOfTimeline: false, addToState: false });
             expect(timeline.getBaseIndex()).toEqual(initialIndex);
             expect(timeline.getEvents().length).toEqual(2);
             expect(timeline.getEvents()[0]).toEqual(events[0]);
@@ -192,9 +192,9 @@ describe("EventTimeline", function () {
         });
 
         it("should be able to add events to the start", function () {
-            timeline.addEvent(events[0], { toStartOfTimeline: true });
+            timeline.addEvent(events[0], { toStartOfTimeline: true, addToState: false });
             const initialIndex = timeline.getBaseIndex();
-            timeline.addEvent(events[1], { toStartOfTimeline: true });
+            timeline.addEvent(events[1], { toStartOfTimeline: true, addToState: false });
             expect(timeline.getBaseIndex()).toEqual(initialIndex + 1);
             expect(timeline.getEvents().length).toEqual(2);
             expect(timeline.getEvents()[0]).toEqual(events[1]);
@@ -238,9 +238,9 @@ describe("EventTimeline", function () {
                 content: { name: "Old Room Name" },
             });
 
-            timeline.addEvent(newEv, { toStartOfTimeline: false });
+            timeline.addEvent(newEv, { toStartOfTimeline: false, addToState: false });
             expect(newEv.sender).toEqual(sentinel);
-            timeline.addEvent(oldEv, { toStartOfTimeline: true });
+            timeline.addEvent(oldEv, { toStartOfTimeline: true, addToState: false });
             expect(oldEv.sender).toEqual(oldSentinel);
         });
 
@@ -280,9 +280,9 @@ describe("EventTimeline", function () {
                 skey: userA,
                 event: true,
             });
-            timeline.addEvent(newEv, { toStartOfTimeline: false });
+            timeline.addEvent(newEv, { toStartOfTimeline: false, addToState: false });
             expect(newEv.target).toEqual(sentinel);
-            timeline.addEvent(oldEv, { toStartOfTimeline: true });
+            timeline.addEvent(oldEv, { toStartOfTimeline: true, addToState: false });
             expect(oldEv.target).toEqual(oldSentinel);
         });
 
@@ -308,8 +308,8 @@ describe("EventTimeline", function () {
                     }),
                 ];
 
-                timeline.addEvent(events[0], { toStartOfTimeline: false });
-                timeline.addEvent(events[1], { toStartOfTimeline: false });
+                timeline.addEvent(events[0], { toStartOfTimeline: false, addToState: true });
+                timeline.addEvent(events[1], { toStartOfTimeline: false, addToState: true });
 
                 expect(timeline.getState(EventTimeline.FORWARDS)!.setStateEvents).toHaveBeenCalledWith([events[0]], {
                     timelineWasEmpty: undefined,
@@ -347,8 +347,8 @@ describe("EventTimeline", function () {
                     }),
                 ];
 
-                timeline.addEvent(events[0], { toStartOfTimeline: true });
-                timeline.addEvent(events[1], { toStartOfTimeline: true });
+                timeline.addEvent(events[0], { toStartOfTimeline: true, addToState: true });
+                timeline.addEvent(events[1], { toStartOfTimeline: true, addToState: true });
 
                 expect(timeline.getState(EventTimeline.BACKWARDS)!.setStateEvents).toHaveBeenCalledWith([events[0]], {
                     timelineWasEmpty: undefined,
@@ -365,11 +365,15 @@ describe("EventTimeline", function () {
         );
 
         it("Make sure legacy overload passing options directly as parameters still works", () => {
-            expect(() => timeline.addEvent(events[0], { toStartOfTimeline: true })).not.toThrow();
+            expect(() => timeline.addEvent(events[0], { toStartOfTimeline: true, addToState: false })).not.toThrow();
             // @ts-ignore stateContext is not a valid param
             expect(() => timeline.addEvent(events[0], { stateContext: new RoomState(roomId) })).not.toThrow();
             expect(() =>
-                timeline.addEvent(events[0], { toStartOfTimeline: false, roomState: new RoomState(roomId) }),
+                timeline.addEvent(events[0], {
+                    toStartOfTimeline: false,
+                    addToState: false,
+                    roomState: new RoomState(roomId),
+                }),
             ).not.toThrow();
         });
     });
@@ -397,8 +401,8 @@ describe("EventTimeline", function () {
         ];
 
         it("should remove events", function () {
-            timeline.addEvent(events[0], { toStartOfTimeline: false });
-            timeline.addEvent(events[1], { toStartOfTimeline: false });
+            timeline.addEvent(events[0], { toStartOfTimeline: false, addToState: false });
+            timeline.addEvent(events[1], { toStartOfTimeline: false, addToState: false });
             expect(timeline.getEvents().length).toEqual(2);
 
             let ev = timeline.removeEvent(events[0].getId()!);
@@ -411,9 +415,9 @@ describe("EventTimeline", function () {
         });
 
         it("should update baseIndex", function () {
-            timeline.addEvent(events[0], { toStartOfTimeline: false });
-            timeline.addEvent(events[1], { toStartOfTimeline: true });
-            timeline.addEvent(events[2], { toStartOfTimeline: false });
+            timeline.addEvent(events[0], { toStartOfTimeline: false, addToState: false });
+            timeline.addEvent(events[1], { toStartOfTimeline: true, addToState: false });
+            timeline.addEvent(events[2], { toStartOfTimeline: false, addToState: false });
             expect(timeline.getEvents().length).toEqual(3);
             expect(timeline.getBaseIndex()).toEqual(1);
 
@@ -430,11 +434,11 @@ describe("EventTimeline", function () {
         // - removing the last event got baseIndex into such a state that
         // further addEvent(ev, false) calls made the index increase.
         it("should not make baseIndex assplode when removing the last event", function () {
-            timeline.addEvent(events[0], { toStartOfTimeline: true });
+            timeline.addEvent(events[0], { toStartOfTimeline: true, addToState: false });
             timeline.removeEvent(events[0].getId()!);
             const initialIndex = timeline.getBaseIndex();
-            timeline.addEvent(events[1], { toStartOfTimeline: false });
-            timeline.addEvent(events[2], { toStartOfTimeline: false });
+            timeline.addEvent(events[1], { toStartOfTimeline: false, addToState: false });
+            timeline.addEvent(events[2], { toStartOfTimeline: false, addToState: false });
             expect(timeline.getBaseIndex()).toEqual(initialIndex);
             expect(timeline.getEvents().length).toEqual(2);
         });

spec/unit/matrix-client.spec.ts

@@ -2799,24 +2799,28 @@ describe("MatrixClient", function () {
                         roomCreateEvent(room1.roomId, replacedByCreate1.roomId),
                         predecessorEvent(room1.roomId, replacedByDynamicPredecessor1.roomId),
                     ],
-                    {},
+                    { addToState: true },
                 );
                 room2.addLiveEvents(
                     [
                         roomCreateEvent(room2.roomId, replacedByCreate2.roomId),
                         predecessorEvent(room2.roomId, replacedByDynamicPredecessor2.roomId),
                     ],
-                    {},
+                    { addToState: true },
                 );
-                replacedByCreate1.addLiveEvents([tombstoneEvent(room1.roomId, replacedByCreate1.roomId)], {});
-                replacedByCreate2.addLiveEvents([tombstoneEvent(room2.roomId, replacedByCreate2.roomId)], {});
+                replacedByCreate1.addLiveEvents([tombstoneEvent(room1.roomId, replacedByCreate1.roomId)], {
+                    addToState: true,
+                });
+                replacedByCreate2.addLiveEvents([tombstoneEvent(room2.roomId, replacedByCreate2.roomId)], {
+                    addToState: true,
+                });
                 replacedByDynamicPredecessor1.addLiveEvents(
                     [tombstoneEvent(room1.roomId, replacedByDynamicPredecessor1.roomId)],
-                    {},
+                    { addToState: true },
                 );
                 replacedByDynamicPredecessor2.addLiveEvents(
                     [tombstoneEvent(room2.roomId, replacedByDynamicPredecessor2.roomId)],
-                    {},
+                    { addToState: true },
                 );
 
                 return {
@@ -2854,10 +2858,10 @@ describe("MatrixClient", function () {
                 const room2 = new Room("room2", client, "@daryl:alexandria.example.com");
                 client.store = new StubStore();
                 client.store.getRooms = () => [room1, replacedRoom1, replacedRoom2, room2];
-                room1.addLiveEvents([roomCreateEvent(room1.roomId, replacedRoom1.roomId)], {});
-                room2.addLiveEvents([roomCreateEvent(room2.roomId, replacedRoom2.roomId)], {});
-                replacedRoom1.addLiveEvents([tombstoneEvent(room1.roomId, replacedRoom1.roomId)], {});
-                replacedRoom2.addLiveEvents([tombstoneEvent(room2.roomId, replacedRoom2.roomId)], {});
+                room1.addLiveEvents([roomCreateEvent(room1.roomId, replacedRoom1.roomId)], { addToState: true });
+                room2.addLiveEvents([roomCreateEvent(room2.roomId, replacedRoom2.roomId)], { addToState: true });
+                replacedRoom1.addLiveEvents([tombstoneEvent(room1.roomId, replacedRoom1.roomId)], { addToState: true });
+                replacedRoom2.addLiveEvents([tombstoneEvent(room2.roomId, replacedRoom2.roomId)], { addToState: true });
 
                 // When we ask for the visible rooms
                 const rooms = client.getVisibleRooms();
@@ -2937,15 +2941,15 @@ describe("MatrixClient", function () {
                 const room4 = new Room("room4", client, "@michonne:hawthorne.example.com");
 
                 if (creates) {
-                    room2.addLiveEvents([roomCreateEvent(room2.roomId, room1.roomId)]);
-                    room3.addLiveEvents([roomCreateEvent(room3.roomId, room2.roomId)]);
-                    room4.addLiveEvents([roomCreateEvent(room4.roomId, room3.roomId)]);
+                    room2.addLiveEvents([roomCreateEvent(room2.roomId, room1.roomId)], { addToState: true });
+                    room3.addLiveEvents([roomCreateEvent(room3.roomId, room2.roomId)], { addToState: true });
+                    room4.addLiveEvents([roomCreateEvent(room4.roomId, room3.roomId)], { addToState: true });
                 }
 
                 if (tombstones) {
-                    room1.addLiveEvents([tombstoneEvent(room2.roomId, room1.roomId)], {});
-                    room2.addLiveEvents([tombstoneEvent(room3.roomId, room2.roomId)], {});
-                    room3.addLiveEvents([tombstoneEvent(room4.roomId, room3.roomId)], {});
+                    room1.addLiveEvents([tombstoneEvent(room2.roomId, room1.roomId)], { addToState: true });
+                    room2.addLiveEvents([tombstoneEvent(room3.roomId, room2.roomId)], { addToState: true });
+                    room3.addLiveEvents([tombstoneEvent(room4.roomId, room3.roomId)], { addToState: true });
                 }
 
                 mocked(store.getRoom).mockImplementation((roomId: string) => {
@@ -2980,17 +2984,17 @@ describe("MatrixClient", function () {
                 const dynRoom4 = new Room("dynRoom4", client, "@rick:grimes.example.com");
                 const dynRoom5 = new Room("dynRoom5", client, "@rick:grimes.example.com");
 
-                dynRoom1.addLiveEvents([tombstoneEvent(dynRoom2.roomId, dynRoom1.roomId)], {});
-                dynRoom2.addLiveEvents([predecessorEvent(dynRoom2.roomId, dynRoom1.roomId)]);
+                dynRoom1.addLiveEvents([tombstoneEvent(dynRoom2.roomId, dynRoom1.roomId)], { addToState: true });
+                dynRoom2.addLiveEvents([predecessorEvent(dynRoom2.roomId, dynRoom1.roomId)], { addToState: true });
 
-                dynRoom2.addLiveEvents([tombstoneEvent(room3.roomId, dynRoom2.roomId)], {});
-                room3.addLiveEvents([predecessorEvent(room3.roomId, dynRoom2.roomId)]);
+                dynRoom2.addLiveEvents([tombstoneEvent(room3.roomId, dynRoom2.roomId)], { addToState: true });
+                room3.addLiveEvents([predecessorEvent(room3.roomId, dynRoom2.roomId)], { addToState: true });
 
-                room3.addLiveEvents([tombstoneEvent(dynRoom4.roomId, room3.roomId)], {});
-                dynRoom4.addLiveEvents([predecessorEvent(dynRoom4.roomId, room3.roomId)]);
+                room3.addLiveEvents([tombstoneEvent(dynRoom4.roomId, room3.roomId)], { addToState: true });
+                dynRoom4.addLiveEvents([predecessorEvent(dynRoom4.roomId, room3.roomId)], { addToState: true });
 
-                dynRoom4.addLiveEvents([tombstoneEvent(dynRoom5.roomId, dynRoom4.roomId)], {});
-                dynRoom5.addLiveEvents([predecessorEvent(dynRoom5.roomId, dynRoom4.roomId)]);
+                dynRoom4.addLiveEvents([tombstoneEvent(dynRoom5.roomId, dynRoom4.roomId)], { addToState: true });
+                dynRoom5.addLiveEvents([predecessorEvent(dynRoom5.roomId, dynRoom4.roomId)], { addToState: true });
 
                 mocked(store.getRoom)
                     .mockClear()

spec/unit/matrixrtc/MatrixRTCSession.spec.ts

@@ -38,6 +38,8 @@ const membershipTemplate: CallMembershipData = {
 
 const mockFocus = { type: "mock" };
 
+const textEncoder = new TextEncoder();
+
 describe("MatrixRTCSession", () => {
     let client: MatrixClient;
     let sess: MatrixRTCSession | undefined;
@@ -864,7 +866,64 @@ describe("MatrixRTCSession", () => {
                 expect(client.cancelPendingEvent).toHaveBeenCalledWith(eventSentinel);
             });
 
-            it("Re-sends key if a new member joins", async () => {
+            it("re-sends key if a new member joins even if a key rotation is in progress", async () => {
+                jest.useFakeTimers();
+                try {
+                    // session with two members
+                    const member2 = Object.assign({}, membershipTemplate, {
+                        device_id: "BBBBBBB",
+                    });
+                    const mockRoom = makeMockRoom([membershipTemplate, member2]);
+                    sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
+
+                    // joining will trigger an initial key send
+                    const keysSentPromise1 = new Promise<EncryptionKeysEventContent>((resolve) => {
+                        sendEventMock.mockImplementation((_roomId, _evType, payload) => resolve(payload));
+                    });
+                    sess.joinRoomSession([mockFocus], mockFocus, {
+                        manageMediaKeys: true,
+                        updateEncryptionKeyThrottle: 1000,
+                        makeKeyDelay: 3000,
+                    });
+                    await keysSentPromise1;
+                    expect(sess!.statistics.counters.roomEventEncryptionKeysSent).toEqual(1);
+
+                    // member2 leaves triggering key rotation
+                    mockRoom.getLiveTimeline().getState = jest
+                        .fn()
+                        .mockReturnValue(makeMockRoomState([membershipTemplate], mockRoom.roomId));
+                    sess.onMembershipUpdate();
+
+                    // member2 re-joins which should trigger an immediate re-send
+                    const keysSentPromise2 = new Promise<EncryptionKeysEventContent>((resolve) => {
+                        sendEventMock.mockImplementation((_roomId, _evType, payload) => resolve(payload));
+                    });
+                    mockRoom.getLiveTimeline().getState = jest
+                        .fn()
+                        .mockReturnValue(makeMockRoomState([membershipTemplate, member2], mockRoom.roomId));
+                    sess.onMembershipUpdate();
+                    // but, that immediate resend is throttled so we need to wait a bit
+                    jest.advanceTimersByTime(1000);
+                    const { keys } = await keysSentPromise2;
+                    expect(sess!.statistics.counters.roomEventEncryptionKeysSent).toEqual(2);
+                    // key index should still be the original: 0
+                    expect(keys[0].index).toEqual(0);
+
+                    // check that the key rotation actually happens
+                    const keysSentPromise3 = new Promise<EncryptionKeysEventContent>((resolve) => {
+                        sendEventMock.mockImplementation((_roomId, _evType, payload) => resolve(payload));
+                    });
+                    jest.advanceTimersByTime(2000);
+                    const { keys: rotatedKeys } = await keysSentPromise3;
+                    expect(sess!.statistics.counters.roomEventEncryptionKeysSent).toEqual(3);
+                    // key index should now be the rotated one: 1
+                    expect(rotatedKeys[0].index).toEqual(1);
+                } finally {
+                    jest.useRealTimers();
+                }
+            });
+
+            it("re-sends key if a new member joins", async () => {
                 jest.useFakeTimers();
                 try {
                     const mockRoom = makeMockRoom([membershipTemplate]);
@@ -1288,7 +1347,7 @@ describe("MatrixRTCSession", () => {
                 sess!.reemitEncryptionKeys();
                 expect(encryptionKeyChangedListener).toHaveBeenCalledTimes(1);
                 expect(encryptionKeyChangedListener).toHaveBeenCalledWith(
-                    Buffer.from("this is the key", "utf-8"),
+                    textEncoder.encode("this is the key"),
                     0,
                     "@bob:example.org:bobsphone",
                 );
@@ -1320,7 +1379,7 @@ describe("MatrixRTCSession", () => {
                 sess!.reemitEncryptionKeys();
                 expect(encryptionKeyChangedListener).toHaveBeenCalledTimes(1);
                 expect(encryptionKeyChangedListener).toHaveBeenCalledWith(
-                    Buffer.from("this is the key", "utf-8"),
+                    textEncoder.encode("this is the key"),
                     4,
                     "@bob:example.org:bobsphone",
                 );
@@ -1352,7 +1411,7 @@ describe("MatrixRTCSession", () => {
                 sess!.reemitEncryptionKeys();
                 expect(encryptionKeyChangedListener).toHaveBeenCalledTimes(1);
                 expect(encryptionKeyChangedListener).toHaveBeenCalledWith(
-                    Buffer.from("this is the key", "utf-8"),
+                    textEncoder.encode("this is the key"),
                     0,
                     "@bob:example.org:bobsphone",
                 );
@@ -1379,12 +1438,12 @@ describe("MatrixRTCSession", () => {
                 sess!.reemitEncryptionKeys();
                 expect(encryptionKeyChangedListener).toHaveBeenCalledTimes(2);
                 expect(encryptionKeyChangedListener).toHaveBeenCalledWith(
-                    Buffer.from("this is the key", "utf-8"),
+                    textEncoder.encode("this is the key"),
                     0,
                     "@bob:example.org:bobsphone",
                 );
                 expect(encryptionKeyChangedListener).toHaveBeenCalledWith(
-                    Buffer.from("this is the key", "utf-8"),
+                    textEncoder.encode("this is the key"),
                     4,
                     "@bob:example.org:bobsphone",
                 );
@@ -1432,7 +1491,7 @@ describe("MatrixRTCSession", () => {
                 sess!.reemitEncryptionKeys();
                 expect(encryptionKeyChangedListener).toHaveBeenCalledTimes(1);
                 expect(encryptionKeyChangedListener).toHaveBeenCalledWith(
-                    Buffer.from("newer key", "utf-8"),
+                    textEncoder.encode("newer key"),
                     0,
                     "@bob:example.org:bobsphone",
                 );
@@ -1480,7 +1539,7 @@ describe("MatrixRTCSession", () => {
                 sess!.reemitEncryptionKeys();
                 expect(encryptionKeyChangedListener).toHaveBeenCalledTimes(1);
                 expect(encryptionKeyChangedListener).toHaveBeenCalledWith(
-                    Buffer.from("second key", "utf-8"),
+                    textEncoder.encode("second key"),
                     0,
                     "@bob:example.org:bobsphone",
                 );

spec/unit/models/event.spec.ts

@@ -99,7 +99,7 @@ describe("MatrixEvent", () => {
             const room = new Room("!roomid:e.xyz", mockClient, "myname");
             const ev = createEvent("$event1:server");
 
-            await room.addLiveEvents([ev]);
+            await room.addLiveEvents([ev], { addToState: false });
             await room.createThreadsTimelineSets();
             expect(ev.threadRootId).toBeUndefined();
             expect(mainTimelineLiveEventIds(room)).toEqual([ev.getId()]);
@@ -120,7 +120,7 @@ describe("MatrixEvent", () => {
             const threadRoot = createEvent("$threadroot:server");
             const ev = createThreadedEvent("$event1:server", threadRoot.getId()!);
 
-            await room.addLiveEvents([threadRoot, ev]);
+            await room.addLiveEvents([threadRoot, ev], { addToState: false });
             await room.createThreadsTimelineSets();
             expect(threadRoot.threadRootId).toEqual(threadRoot.getId());
             expect(mainTimelineLiveEventIds(room)).toEqual([threadRoot.getId()]);
@@ -143,7 +143,7 @@ describe("MatrixEvent", () => {
             const threadRoot = createEvent("$threadroot:server");
             const ev = createThreadedEvent("$event1:server", threadRoot.getId()!);
 
-            await room.addLiveEvents([threadRoot, ev]);
+            await room.addLiveEvents([threadRoot, ev], { addToState: false });
             await room.createThreadsTimelineSets();
             expect(ev.threadRootId).toEqual(threadRoot.getId());
             expect(mainTimelineLiveEventIds(room)).toEqual([threadRoot.getId()]);
@@ -167,7 +167,7 @@ describe("MatrixEvent", () => {
             const ev = createThreadedEvent("$event1:server", threadRoot.getId()!);
             const reaction = createReactionEvent("$reaction:server", ev.getId()!);
 
-            await room.addLiveEvents([threadRoot, ev, reaction]);
+            await room.addLiveEvents([threadRoot, ev, reaction], { addToState: false });
             await room.createThreadsTimelineSets();
             expect(reaction.threadRootId).toEqual(threadRoot.getId());
             expect(mainTimelineLiveEventIds(room)).toEqual([threadRoot.getId()]);
@@ -191,7 +191,7 @@ describe("MatrixEvent", () => {
             const ev = createThreadedEvent("$event1:server", threadRoot.getId()!);
             const edit = createEditEvent("$edit:server", ev.getId()!);
 
-            await room.addLiveEvents([threadRoot, ev, edit]);
+            await room.addLiveEvents([threadRoot, ev, edit], { addToState: false });
             await room.createThreadsTimelineSets();
             expect(edit.threadRootId).toEqual(threadRoot.getId());
             expect(mainTimelineLiveEventIds(room)).toEqual([threadRoot.getId()]);
@@ -217,7 +217,7 @@ describe("MatrixEvent", () => {
             const reply2 = createReplyEvent("$reply2:server", reply1.getId()!);
             const reaction = createReactionEvent("$reaction:server", reply2.getId()!);
 
-            await room.addLiveEvents([threadRoot, ev, reply1, reply2, reaction]);
+            await room.addLiveEvents([threadRoot, ev, reply1, reply2, reaction], { addToState: false });
             await room.createThreadsTimelineSets();
             expect(reaction.threadRootId).toEqual(threadRoot.getId());
             expect(mainTimelineLiveEventIds(room)).toEqual([threadRoot.getId()]);

spec/unit/models/room-receipts.spec.ts

@@ -36,7 +36,7 @@ describe("RoomReceipts", () => {
         // Given there are no receipts in the room
         const room = createRoom();
         const [event] = createEvent();
-        room.addLiveEvents([event]);
+        room.addLiveEvents([event], { addToState: false });
 
         // When I ask about any event, then it is unread
         expect(room.hasUserReadEvent(readerId, event.getId()!)).toBe(false);
@@ -46,7 +46,7 @@ describe("RoomReceipts", () => {
         // Given there are no receipts in the room
         const room = createRoom();
         const [event] = createEventSentBy(readerId);
-        room.addLiveEvents([event]);
+        room.addLiveEvents([event], { addToState: false });
 
         // When I ask about an event I sent, it is read (because a synthetic
         // receipt was created and stored in RoomReceipts)
@@ -57,7 +57,7 @@ describe("RoomReceipts", () => {
         // Given my event exists and is unread
         const room = createRoom();
         const [event, eventId] = createEvent();
-        room.addLiveEvents([event]);
+        room.addLiveEvents([event], { addToState: false });
         expect(room.hasUserReadEvent(readerId, eventId)).toBe(false);
 
         // When we receive a receipt for this event+user
@@ -72,7 +72,7 @@ describe("RoomReceipts", () => {
         const room = createRoom();
         const [event1, event1Id] = createEvent();
         const [event2] = createEvent();
-        room.addLiveEvents([event1, event2]);
+        room.addLiveEvents([event1, event2], { addToState: false });
 
         // When we receive a receipt for the later event
         room.addReceipt(createReceipt(readerId, event2));
@@ -86,7 +86,7 @@ describe("RoomReceipts", () => {
         const room = createRoom();
         const [oldEvent, oldEventId] = createEvent();
         const [liveEvent] = createEvent();
-        room.addLiveEvents([liveEvent]);
+        room.addLiveEvents([liveEvent], { addToState: false });
         createOldTimeline(room, [oldEvent]);
 
         // When we receive a receipt for the live event
@@ -120,7 +120,7 @@ describe("RoomReceipts", () => {
         const room = createRoom();
         const [event1] = createEvent();
         const [event2, event2Id] = createEvent();
-        room.addLiveEvents([event1, event2]);
+        room.addLiveEvents([event1, event2], { addToState: false });
 
         // When we receive a receipt for the earlier event
         room.addReceipt(createReceipt(readerId, event1));
@@ -133,7 +133,7 @@ describe("RoomReceipts", () => {
         // Given my event exists and is unread
         const room = createRoom();
         const [event, eventId] = createEvent();
-        room.addLiveEvents([event]);
+        room.addLiveEvents([event], { addToState: false });
         expect(room.hasUserReadEvent(readerId, eventId)).toBe(false);
 
         // When we receive a receipt for another user
@@ -151,7 +151,7 @@ describe("RoomReceipts", () => {
         const room = createRoom();
         const [previousEvent] = createEvent();
         const [myEvent] = createEventSentBy(readerId);
-        room.addLiveEvents([previousEvent, myEvent]);
+        room.addLiveEvents([previousEvent, myEvent], { addToState: false });
 
         // And I just received a receipt for the previous event
         room.addReceipt(createReceipt(readerId, previousEvent));
@@ -165,7 +165,7 @@ describe("RoomReceipts", () => {
         const room = createRoom();
         const [myEvent] = createEventSentBy(readerId);
         const [laterEvent] = createEvent();
-        room.addLiveEvents([myEvent, laterEvent]);
+        room.addLiveEvents([myEvent, laterEvent], { addToState: false });
 
         // When I ask about the later event, it is unread (because it's after the synthetic receipt)
         expect(room.hasUserReadEvent(readerId, laterEvent.getId()!)).toBe(false);
@@ -177,7 +177,7 @@ describe("RoomReceipts", () => {
         const [event1] = createEvent();
         const [event2, event2Id] = createEvent();
         const [event3, event3Id] = createEvent();
-        room.addLiveEvents([event1, event2, event3]);
+        room.addLiveEvents([event1, event2, event3], { addToState: false });
 
         // When we receive receipts for the older events out of order
         room.addReceipt(createReceipt(readerId, event2));
@@ -192,7 +192,7 @@ describe("RoomReceipts", () => {
         // Given my event exists and is unread
         const room = createRoom();
         const [event, eventId] = createEvent();
-        room.addLiveEvents([event]);
+        room.addLiveEvents([event], { addToState: false });
         expect(room.hasUserReadEvent(readerId, eventId)).toBe(false);
 
         // When we receive a receipt for this event+user
@@ -208,7 +208,7 @@ describe("RoomReceipts", () => {
         const [root, rootId] = createEvent();
         const [event, eventId] = createThreadedEvent(root);
         setupThread(room, root);
-        room.addLiveEvents([root, event]);
+        room.addLiveEvents([root, event], { addToState: false });
         expect(room.hasUserReadEvent(readerId, eventId)).toBe(false);
 
         // When we receive a receipt for this event on this thread
@@ -225,7 +225,7 @@ describe("RoomReceipts", () => {
         const [event1, event1Id] = createThreadedEvent(root);
         const [event2] = createThreadedEvent(root);
         setupThread(room, root);
-        room.addLiveEvents([root, event1, event2]);
+        room.addLiveEvents([root, event1, event2], { addToState: false });
 
         // When we receive a receipt for the later event
         room.addReceipt(createThreadedReceipt(readerId, event2, rootId));
@@ -241,7 +241,7 @@ describe("RoomReceipts", () => {
         const [event1] = createThreadedEvent(root);
         const [event2, event2Id] = createThreadedEvent(root);
         setupThread(room, root);
-        room.addLiveEvents([root, event1, event2]);
+        room.addLiveEvents([root, event1, event2], { addToState: false });
 
         // When we receive a receipt for the earlier event
         room.addReceipt(createThreadedReceipt(readerId, event1, rootId));
@@ -256,7 +256,7 @@ describe("RoomReceipts", () => {
         const [root, rootId] = createEvent();
         const [event, eventId] = createThreadedEvent(root);
         setupThread(room, root);
-        room.addLiveEvents([root, event]);
+        room.addLiveEvents([root, event], { addToState: false });
         expect(room.hasUserReadEvent(readerId, eventId)).toBe(false);
 
         // When we receive a receipt for another user
@@ -278,7 +278,7 @@ describe("RoomReceipts", () => {
         const [thread2] = createThreadedEvent(root2);
         setupThread(room, root1);
         setupThread(room, root2);
-        room.addLiveEvents([root1, root2, thread1, thread2]);
+        room.addLiveEvents([root1, root2, thread1, thread2], { addToState: false });
 
         // When we receive a receipt for the later event
         room.addReceipt(createThreadedReceipt(readerId, thread2, root2.getId()!));
@@ -295,7 +295,7 @@ describe("RoomReceipts", () => {
         const [event2, event2Id] = createThreadedEvent(root);
         const [event3, event3Id] = createThreadedEvent(root);
         setupThread(room, root);
-        room.addLiveEvents([root, event1, event2, event3]);
+        room.addLiveEvents([root, event1, event2, event3], { addToState: false });
 
         // When we receive receipts for the older events out of order
         room.addReceipt(createThreadedReceipt(readerId, event2, rootId));
@@ -329,7 +329,7 @@ describe("RoomReceipts", () => {
         const [thread2b, thread2bId] = createThreadedEvent(main2);
         setupThread(room, main1);
         setupThread(room, main2);
-        room.addLiveEvents([main1, thread1a, thread1b, main2, thread2a, main3, thread2b]);
+        room.addLiveEvents([main1, thread1a, thread1b, main2, thread2a, main3, thread2b], { addToState: false });
 
         // And the timestamps on the events are consistent with the order above
         main1.event.origin_server_ts = 1;
@@ -377,7 +377,7 @@ describe("RoomReceipts", () => {
 
             // Add the event to the room
             // The receipt is removed from the dangling state
-            room.addLiveEvents([event]);
+            room.addLiveEvents([event], { addToState: false });
 
             // Then the event is read
             expect(room.hasUserReadEvent(readerId, eventId)).toBe(true);
@@ -398,7 +398,7 @@ describe("RoomReceipts", () => {
 
             // Add the events to the room
             // The receipt is removed from the dangling state
-            room.addLiveEvents([root, event]);
+            room.addLiveEvents([root, event], { addToState: false });
 
             // Then the event is read
             expect(room.hasUserReadEvent(readerId, eventId)).toBe(true);
@@ -418,7 +418,7 @@ describe("RoomReceipts", () => {
 
             // Add the event to the room
             // The two receipts should be processed
-            room.addLiveEvents([event]);
+            room.addLiveEvents([event], { addToState: false });
 
             // Then the event is read
             // We expect that the receipt of `otherUserId` didn't replace/erase the receipt of `readerId`
@@ -528,7 +528,7 @@ function createThreadedReceipt(userId: string, referencedEvent: MatrixEvent, thr
  */
 function createOldTimeline(room: Room, events: MatrixEvent[]) {
     const oldTimeline = room.getUnfilteredTimelineSet().addTimeline();
-    room.getUnfilteredTimelineSet().addEventsToTimeline(events, true, oldTimeline);
+    room.getUnfilteredTimelineSet().addEventsToTimeline(events, true, false, oldTimeline);
 }
 
 /**

spec/unit/models/thread.spec.ts

@@ -801,7 +801,7 @@ async function createThread(client: MatrixClient, user: string, roomId: string):
 
     // Ensure the root is in the room timeline
     root.setThreadId(root.getId());
-    await room.addLiveEvents([root]);
+    await room.addLiveEvents([root], { addToState: false });
 
     // Create the thread and wait for it to be initialised
     const thread = room.createThread(root.getId()!, root, [], false);

spec/unit/notifications.spec.ts

@@ -106,7 +106,7 @@ describe("fixNotificationCountOnDecryption", () => {
             mockClient,
         );
 
-        room.addLiveEvents([event]);
+        room.addLiveEvents([event], { addToState: false });
 
         THREAD_ID = event.getId()!;
         threadEvent = mkEvent({

spec/unit/relations.spec.ts

@@ -198,8 +198,8 @@ describe("Relations", function () {
             });
 
             const timelineSet = new EventTimelineSet(room);
-            timelineSet.addLiveEvent(targetEvent);
-            timelineSet.addLiveEvent(relationEvent);
+            timelineSet.addLiveEvent(targetEvent, { addToState: false });
+            timelineSet.addLiveEvent(relationEvent, { addToState: false });
 
             await relationsCreated;
         }
@@ -212,8 +212,8 @@ describe("Relations", function () {
             });
 
             const timelineSet = new EventTimelineSet(room);
-            timelineSet.addLiveEvent(relationEvent);
-            timelineSet.addLiveEvent(targetEvent);
+            timelineSet.addLiveEvent(relationEvent, { addToState: false });
+            timelineSet.addLiveEvent(targetEvent, { addToState: false });
 
             await relationsCreated;
         }

spec/unit/room-member.spec.ts

@@ -486,7 +486,43 @@ describe("RoomMember", function () {
             } as unknown as RoomState;
             expect(member.name).toEqual(userA); // default = user_id
             member.setMembershipEvent(joinEvent, roomState);
-            expect(member.name).not.toEqual("Alíce"); // it should disambig.
+            expect(member.name).toEqual("Alíce​ (@alice:bar)"); // it should disambig.
+            // user_id should be there somewhere
+            expect(member.name.indexOf(userA)).not.toEqual(-1);
+        });
+
+        it("should disambiguate a user when their displayname looks like an MXID which isn't theirs", function () {
+            const joinEvent = utils.mkMembership({
+                event: true,
+                mship: KnownMembership.Join,
+                user: userA,
+                room: roomId,
+                name: "@clarissa\u0a83bar",
+            });
+
+            const roomState = {
+                getStateEvents: function (type: string) {
+                    if (type !== "m.room.member") {
+                        return [];
+                    }
+                    return [
+                        utils.mkMembership({
+                            event: true,
+                            mship: KnownMembership.Join,
+                            room: roomId,
+                            user: userC,
+                            name: "Alice",
+                        }),
+                        joinEvent,
+                    ];
+                },
+                getUserIdsWithDisplayName: function (displayName: string) {
+                    return [userA, userC];
+                },
+            } as unknown as RoomState;
+            expect(member.name).toEqual(userA); // default = user_id
+            member.setMembershipEvent(joinEvent, roomState);
+            expect(member.name).toEqual("@clarissaઃbar (@alice:bar)"); // it should disambig.
             // user_id should be there somewhere
             expect(member.name.indexOf(userA)).not.toEqual(-1);
         });

spec/unit/room-state.spec.ts

@@ -1122,59 +1122,4 @@ describe("RoomState", function () {
             ).toBeFalsy();
         });
     });
-    describe("skipWrongOrderRoomStateInserts", () => {
-        const idNow = "now";
-        const idBefore = "before";
-        const endState = new RoomState(roomId);
-        const startState = new RoomState(roomId, undefined, true);
-
-        let onRoomStateEvent: (event: MatrixEvent, state: RoomState, lastStateEvent: MatrixEvent | null) => void;
-        const evNow = new MatrixEvent({
-            type: "m.call.member",
-            room_id: roomId,
-            state_key: "@user:example.org",
-            content: {},
-        });
-        evNow.event.unsigned = { replaces_state: idBefore };
-        evNow.event.event_id = idNow;
-
-        const evBefore = new MatrixEvent({
-            type: "m.call.member",
-            room_id: roomId,
-            state_key: "@user:example.org",
-            content: {},
-        });
-
-        const updatedStateWithBefore = jest.fn();
-        const updatedStateWithNow = jest.fn();
-
-        beforeEach(() => {
-            evBefore.event.event_id = idBefore;
-            onRoomStateEvent = (event, _state, _lastState) => {
-                if (event.event.event_id === idNow) {
-                    updatedStateWithNow();
-                } else if (event.event.event_id === idBefore) {
-                    updatedStateWithBefore();
-                }
-            };
-            endState.on(RoomStateEvent.Events, onRoomStateEvent);
-            startState.on(RoomStateEvent.Events, onRoomStateEvent);
-        });
-        afterEach(() => {
-            endState.off(RoomStateEvent.Events, onRoomStateEvent);
-            startState.off(RoomStateEvent.Events, onRoomStateEvent);
-            updatedStateWithNow.mockReset();
-            updatedStateWithBefore.mockReset();
-        });
-        it("should skip inserting state to the end of the timeline if the current endState events replaces_state id is the same as the inserted events id", () => {
-            endState.setStateEvents([evNow, evBefore]);
-            expect(updatedStateWithBefore).not.toHaveBeenCalled();
-            expect(updatedStateWithNow).toHaveBeenCalled();
-        });
-        it("should skip inserting state at the beginning of the timeline if the inserted events replaces_state is the event id of the current startState", () => {
-            startState.setStateEvents([evBefore, evNow]);
-            expect(updatedStateWithBefore).toHaveBeenCalled();
-            expect(updatedStateWithNow).not.toHaveBeenCalled();
-        });
-    });
 });

spec/unit/rust-crypto/rust-crypto.spec.ts

@@ -572,15 +572,37 @@ describe("RustCrypto", () => {
         });
 
         it("emits VerificationRequestReceived on incoming m.key.verification.request", async () => {
+            rustCrypto = await makeTestRustCrypto(
+                new MatrixHttpApi(new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>(), {
+                    baseUrl: "http://server/",
+                    prefix: "",
+                    onlyData: true,
+                }),
+                testData.TEST_USER_ID,
+            );
+
+            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,
+                    },
+                },
+            });
+
+            // wait until we know about the other device
+            rustCrypto.onSyncCompleted({});
+            await rustCrypto.getUserDeviceInfo([testData.TEST_USER_ID]);
+
             const toDeviceEvent = {
                 type: "m.key.verification.request",
                 content: {
-                    from_device: "testDeviceId",
+                    from_device: testData.TEST_DEVICE_ID,
                     methods: ["m.sas.v1"],
                     transaction_id: "testTxn",
                     timestamp: Date.now() - 1000,
                 },
-                sender: "@user:id",
+                sender: testData.TEST_USER_ID,
             };
 
             const onEvent = jest.fn();
@@ -991,23 +1013,41 @@ describe("RustCrypto", () => {
         });
 
         it.each([
-            [undefined, null],
-            ["Encrypted by an unverified user.", EventShieldReason.UNVERIFIED_IDENTITY],
-            ["Encrypted by a device not verified by its owner.", EventShieldReason.UNSIGNED_DEVICE],
+            [undefined, undefined, null],
+            [
+                "Encrypted by an unverified user.",
+                RustSdkCryptoJs.ShieldStateCode.UnverifiedIdentity,
+                EventShieldReason.UNVERIFIED_IDENTITY,
+            ],
+            [
+                "Encrypted by a device not verified by its owner.",
+                RustSdkCryptoJs.ShieldStateCode.UnsignedDevice,
+                EventShieldReason.UNSIGNED_DEVICE,
+            ],
             [
                 "The authenticity of this encrypted message can't be guaranteed on this device.",
+                RustSdkCryptoJs.ShieldStateCode.AuthenticityNotGuaranteed,
                 EventShieldReason.AUTHENTICITY_NOT_GUARANTEED,
             ],
-            ["Encrypted by an unknown or deleted device.", EventShieldReason.UNKNOWN_DEVICE],
-            ["bloop", EventShieldReason.UNKNOWN],
-        ])("gets the right shield reason (%s)", async (rustReason, expectedReason) => {
+            [
+                "Encrypted by an unknown or deleted device.",
+                RustSdkCryptoJs.ShieldStateCode.UnknownDevice,
+                EventShieldReason.UNKNOWN_DEVICE,
+            ],
+            ["Not encrypted.", RustSdkCryptoJs.ShieldStateCode.SentInClear, EventShieldReason.SENT_IN_CLEAR],
+            [
+                "Encrypted by a previously-verified user who is no longer verified.",
+                RustSdkCryptoJs.ShieldStateCode.VerificationViolation,
+                EventShieldReason.VERIFICATION_VIOLATION,
+            ],
+        ])("gets the right shield reason (%s)", async (rustReason, rustCode, expectedReason) => {
             // suppress the warning from the unknown shield reason
             jest.spyOn(console, "warn").mockImplementation(() => {});
 
             const mockEncryptionInfo = {
                 shieldState: jest
                     .fn()
-                    .mockReturnValue({ color: RustSdkCryptoJs.ShieldColor.None, message: rustReason }),
+                    .mockReturnValue({ color: RustSdkCryptoJs.ShieldColor.None, code: rustCode, message: rustReason }),
             } as unknown as RustSdkCryptoJs.EncryptionInfo;
             olmMachine.getRoomEventEncryptionInfo.mockResolvedValue(mockEncryptionInfo);
 
@@ -1526,6 +1566,20 @@ describe("RustCrypto", () => {
                 failures: 1,
             });
         });
+
+        describe("getKeyBackupInfo", () => {
+            it("should return the current key backup info", async () => {
+                fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);
+
+                const rustCrypto = await makeTestRustCrypto(makeMatrixHttpApi());
+                await expect(rustCrypto.getKeyBackupInfo()).resolves.toStrictEqual(testData.SIGNED_BACKUP_DATA);
+            });
+
+            it("should return null if not available", async () => {
+                const rustCrypto = await makeTestRustCrypto(makeMatrixHttpApi());
+                await expect(rustCrypto.getKeyBackupInfo()).resolves.toBeNull();
+            });
+        });
     });
 
     describe("device dehydration", () => {

spec/unit/sync-accumulator.spec.ts

@@ -17,8 +17,10 @@ limitations under the License.
 
 import { ReceiptType } from "../../src/@types/read_receipts";
 import {
-    IJoinedRoom,
+    Category,
     IInvitedRoom,
+    IInviteState,
+    IJoinedRoom,
     IKnockedRoom,
     IKnockState,
     ILeftRoom,
@@ -27,7 +29,6 @@ import {
     IStrippedState,
     ISyncResponse,
     SyncAccumulator,
-    IInviteState,
 } from "../../src/sync-accumulator";
 import { IRoomSummary } from "../../src";
 import * as utils from "../test-utils/test-utils";
@@ -85,6 +86,7 @@ describe("SyncAccumulator", function () {
         // technically cheating since we also cheekily pre-populate keys we
         // know that the sync accumulator will pre-populate.
         // It isn't 100% transitive.
+        const events = [member("alice", KnownMembership.Join), member("bob", KnownMembership.Join)];
         const res = {
             next_batch: "abc",
             rooms: {
@@ -92,18 +94,17 @@ describe("SyncAccumulator", function () {
                 leave: {},
                 join: {
                     "!foo:bar": {
-                        account_data: { events: [] },
-                        ephemeral: { events: [] },
-                        unread_notifications: {},
-                        state: {
-                            events: [member("alice", KnownMembership.Join), member("bob", KnownMembership.Join)],
-                        },
-                        summary: {
+                        "account_data": { events: [] },
+                        "ephemeral": { events: [] },
+                        "unread_notifications": {},
+                        "org.matrix.msc4222.state_after": { events },
+                        "state": { events },
+                        "summary": {
                             "m.heroes": undefined,
                             "m.joined_member_count": undefined,
                             "m.invited_member_count": undefined,
                         },
-                        timeline: {
+                        "timeline": {
                             events: [msg("alice", "hi")],
                             prev_batch: "something",
                         },
@@ -882,6 +883,147 @@ describe("SyncAccumulator", function () {
             ).not.toBeUndefined();
         });
     });
+
+    describe("msc4222", () => {
+        it("should accumulate state_after events", () => {
+            const initState = {
+                events: [member("alice", KnownMembership.Knock)],
+            };
+            sa.accumulate(
+                syncSkeleton({
+                    "org.matrix.msc4222.state_after": initState,
+                }),
+            );
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].state).toEqual(initState);
+
+            sa.accumulate(
+                syncSkeleton({
+                    "org.matrix.msc4222.state_after": {
+                        events: [
+                            utils.mkEvent({
+                                user: "alice",
+                                room: "!knock:bar",
+                                type: "m.room.name",
+                                content: {
+                                    name: "Room 1",
+                                },
+                                skey: "",
+                            }) as IStateEvent,
+                        ],
+                    },
+                }),
+            );
+
+            expect(
+                sa.getJSON().roomsData[Category.Join]["!foo:bar"].state?.events.find((e) => e.type === "m.room.name")
+                    ?.content.name,
+            ).toEqual("Room 1");
+
+            sa.accumulate(
+                syncSkeleton({
+                    "org.matrix.msc4222.state_after": {
+                        events: [
+                            utils.mkEvent({
+                                user: "alice",
+                                room: "!knock:bar",
+                                type: "m.room.name",
+                                content: {
+                                    name: "Room 2",
+                                },
+                                skey: "",
+                            }) as IStateEvent,
+                        ],
+                    },
+                }),
+            );
+
+            expect(
+                sa.getJSON().roomsData[Category.Join]["!foo:bar"].state?.events.find((e) => e.type === "m.room.name")
+                    ?.content.name,
+            ).toEqual("Room 2");
+        });
+
+        it("should ignore state events in timeline", () => {
+            const initState = {
+                events: [member("alice", KnownMembership.Knock)],
+            };
+            sa.accumulate(
+                syncSkeleton({
+                    "org.matrix.msc4222.state_after": initState,
+                }),
+            );
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].state).toEqual(initState);
+
+            sa.accumulate(
+                syncSkeleton({
+                    "org.matrix.msc4222.state_after": {
+                        events: [],
+                    },
+                    "timeline": {
+                        events: [
+                            utils.mkEvent({
+                                user: "alice",
+                                room: "!knock:bar",
+                                type: "m.room.name",
+                                content: {
+                                    name: "Room 1",
+                                },
+                                skey: "",
+                            }) as IStateEvent,
+                        ],
+                        prev_batch: "something",
+                    },
+                }),
+            );
+
+            expect(
+                sa.getJSON().roomsData[Category.Join]["!foo:bar"].state?.events.find((e) => e.type === "m.room.name")
+                    ?.content.name,
+            ).not.toEqual("Room 1");
+        });
+
+        it("should not rewind state_after to start of timeline in toJSON", () => {
+            const initState = {
+                events: [member("alice", KnownMembership.Knock)],
+            };
+            sa.accumulate(
+                syncSkeleton({
+                    "org.matrix.msc4222.state_after": initState,
+                    "timeline": {
+                        events: initState.events,
+                        prev_batch: null,
+                    },
+                }),
+            );
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].state).toEqual(initState);
+
+            const joinEvent = member("alice", KnownMembership.Join);
+            joinEvent.unsigned = { prev_content: initState.events[0].content, prev_sender: initState.events[0].sender };
+            sa.accumulate(
+                syncSkeleton({
+                    "org.matrix.msc4222.state_after": {
+                        events: [joinEvent],
+                    },
+                    "timeline": {
+                        events: [joinEvent],
+                        prev_batch: "something",
+                    },
+                }),
+            );
+
+            const roomData = sa.getJSON().roomsData[Category.Join]["!foo:bar"];
+            expect(roomData.state?.events.find((e) => e.type === "m.room.member")?.content.membership).toEqual(
+                KnownMembership.Knock,
+            );
+            expect(
+                roomData["org.matrix.msc4222.state_after"]?.events.find((e) => e.type === "m.room.member")?.content
+                    .membership,
+            ).toEqual(KnownMembership.Join);
+            expect(roomData.timeline?.events.find((e) => e.type === "m.room.member")?.content.membership).toEqual(
+                KnownMembership.Join,
+            );
+        });
+    });
 });
 
 function syncSkeleton(
@@ -961,5 +1103,6 @@ function member(localpart: string, membership: Membership) {
         state_key: "@" + localpart + ":localhost",
         sender: "@" + localpart + ":localhost",
         type: "m.room.member",
+        unsigned: {},
     };
 }

spec/unit/timeline-window.spec.ts

@@ -62,7 +62,7 @@ function addEventsToTimeline(timeline: EventTimeline, numEvents: number, toStart
                 user: USER_ID,
                 event: true,
             }),
-            { toStartOfTimeline },
+            { toStartOfTimeline, addToState: false },
         );
     }
 }
@@ -451,8 +451,8 @@ describe("TimelineWindow", function () {
             const liveEvents = createEvents(5);
             const [, , e3, e4, e5] = oldEvents;
             const [, e7, e8, e9, e10] = liveEvents;
-            room.addLiveEvents(liveEvents);
-            room.addEventsToTimeline(oldEvents, true, oldTimeline);
+            room.addLiveEvents(liveEvents, { addToState: false });
+            room.addEventsToTimeline(oldEvents, true, false, oldTimeline);
 
             // And 2 windows over the timelines in this room
             const oldWindow = new TimelineWindow(mockClient, timelineSet);

spec/unit/utils.spec.ts

@@ -32,6 +32,7 @@ import {
     MapWithDefault,
     globToRegexp,
     escapeRegExp,
+    removeHiddenChars,
 } from "../../src/utils";
 import { logger } from "../../src/logger";
 import { mkMessage } from "../test-utils/test-utils";
@@ -740,4 +741,19 @@ describe("utils", function () {
             expect(result).toMatchInlineSnapshot(`"\\[FIT-Connect Zustelldienst \\\\\\(Testumgebung\\\\\\)\\]"`);
         });
     });
+
+    describe("removeHiddenChars", () => {
+        it.each([
+            ["various width spaces U+2000 - U+200D", "\u2000\u200D", ""],
+            ["LTR and RTL marks U+200E and U+200F", "\u200E\u200F", ""],
+            ["LTR/RTL and other directional formatting marks U+202A - U+202F", "\u202A\u202F", ""],
+            ["Arabic Letter RTL mark U+061C", "\u061C", ""],
+            ["Combining characters U+0300 - U+036F", "\u3000\u036F", ""],
+            ["Zero width no-break space (BOM) U+FEFF", "\uFEFF", ""],
+            ["Blank/invisible characters (U2800, U2062-U2063)", "\u2800\u2062\u2063", ""],
+            ["Zero Width Non Joiner", "‌", ""],
+        ])("should strip invisible characters: %s", (_, input, expected) => {
+            expect(removeHiddenChars(input)).toBe(expected);
+        });
+    });
 });

spec/unit/webrtc/groupCall.spec.ts

@@ -1430,7 +1430,7 @@ describe("Group Call", function () {
         let client: MatrixClient;
 
         beforeEach(() => {
-            client = new MatrixClient({ baseUrl: "base_url" });
+            client = new MatrixClient({ baseUrl: "base_url", userId: "my_user_id" });
 
             jest.spyOn(client, "sendStateEvent").mockResolvedValue({} as any);
         });
@@ -1566,16 +1566,19 @@ describe("Group Call", function () {
                 async (roomId, eventType, content, stateKey) => {
                     const eventId = `$${Math.random()}`;
                     if (roomId === room.roomId) {
-                        room.addLiveEvents([
-                            new MatrixEvent({
-                                event_id: eventId,
-                                type: eventType,
-                                room_id: roomId,
-                                sender: FAKE_USER_ID_2,
-                                content,
-                                state_key: stateKey,
-                            }),
-                        ]);
+                        room.addLiveEvents(
+                            [
+                                new MatrixEvent({
+                                    event_id: eventId,
+                                    type: eventType,
+                                    room_id: roomId,
+                                    sender: FAKE_USER_ID_2,
+                                    content,
+                                    state_key: stateKey,
+                                }),
+                            ],
+                            { addToState: true },
+                        );
                     }
                     return { event_id: eventId };
                 },

src/@types/global.d.ts

@@ -65,6 +65,26 @@ declare global {
     interface Navigator {
         // We check for the webkit-prefixed getUserMedia to detect if we're
         // on webkit: we should check if we still need to do this
-        webkitGetUserMedia: DummyInterfaceWeShouldntBeUsingThis;
+        webkitGetUserMedia?: DummyInterfaceWeShouldntBeUsingThis;
+    }
+
+    export interface Uint8ArrayToBase64Options {
+        alphabet?: "base64" | "base64url";
+        omitPadding?: boolean;
+    }
+
+    interface Uint8Array {
+        // https://tc39.es/proposal-arraybuffer-base64/spec/#sec-uint8array.prototype.tobase64
+        toBase64?(options?: Uint8ArrayToBase64Options): string;
+    }
+
+    export interface Uint8ArrayFromBase64Options {
+        alphabet?: "base64"; // Our fallback code only handles base64.
+        lastChunkHandling?: "loose"; // Our fallback code doesn't support other handling at this time.
+    }
+
+    interface Uint8ArrayConstructor {
+        // https://tc39.es/proposal-arraybuffer-base64/spec/#sec-uint8array.frombase64
+        fromBase64?(base64: string, options?: Uint8ArrayFromBase64Options): Uint8Array;
     }
 }

src/autodiscovery.ts

@@ -130,7 +130,7 @@ export class AutoDiscovery {
      * configuration, which may include error states. Rejects on unexpected
      * failure, not when verification fails.
      */
-    public static async fromDiscoveryConfig(wellknown: IClientWellKnown): Promise<ClientConfig> {
+    public static async fromDiscoveryConfig(wellknown?: IClientWellKnown): Promise<ClientConfig> {
         // Step 1 is to get the config, which is provided to us here.
 
         // We default to an error state to make the first few checks easier to

src/base64.ts

@@ -18,30 +18,32 @@ limitations under the License.
  * Base64 encoding and decoding utilities
  */
 
+function toBase64(uint8Array: Uint8Array, options: Uint8ArrayToBase64Options): string {
+    if (typeof uint8Array.toBase64 === "function") {
+        // Currently this is only supported in Firefox,
+        // but we match the options in the hope in the future we can rely on it for all environments.
+        // https://tc39.es/proposal-arraybuffer-base64/spec/#sec-uint8array.prototype.tobase64
+        return uint8Array.toBase64(options);
+    }
+
+    let base64 = btoa(uint8Array.reduce((acc, current) => acc + String.fromCharCode(current), ""));
+    if (options.omitPadding) {
+        base64 = base64.replace(/={1,2}$/, "");
+    }
+    if (options.alphabet === "base64url") {
+        base64 = base64.replace(/\+/g, "-").replace(/\//g, "_");
+    }
+
+    return base64;
+}
+
 /**
  * Encode a typed array of uint8 as base64.
  * @param uint8Array - The data to encode.
  * @returns The base64.
  */
-export function encodeBase64(uint8Array: ArrayBuffer | Uint8Array): string {
-    // A brief note on the state of base64 encoding in Javascript.
-    // As of 2023, there is still no common native impl between both browsers and
-    // node. Older Webpack provides an impl for Buffer and there is a polyfill class
-    // for it. There are also plenty of pure js impls, eg. base64-js which has 2336
-    // dependents at current count. Using this would probably be fine although it's
-    // a little under-docced and run by an individual. The node impl works fine,
-    // the browser impl works but predates Uint8Array and so only uses strings.
-    // Right now, switching between native (or polyfilled) impls like this feels
-    // like the least bad option, but... *shrugs*.
-    if (typeof Buffer === "function") {
-        return Buffer.from(uint8Array).toString("base64");
-    } else if (typeof btoa === "function" && uint8Array instanceof Uint8Array) {
-        // ArrayBuffer is a node concept so the param should always be a Uint8Array on
-        // the browser. We need to check because ArrayBuffers don't have reduce.
-        return btoa(uint8Array.reduce((acc, current) => acc + String.fromCharCode(current), ""));
-    } else {
-        throw new Error("No base64 impl found!");
-    }
+export function encodeBase64(uint8Array: Uint8Array): string {
+    return toBase64(uint8Array, { alphabet: "base64", omitPadding: false });
 }
 
 /**
@@ -49,8 +51,8 @@ export function encodeBase64(uint8Array: ArrayBuffer | Uint8Array): string {
  * @param uint8Array - The data to encode.
  * @returns The unpadded base64.
  */
-export function encodeUnpaddedBase64(uint8Array: ArrayBuffer | Uint8Array): string {
-    return encodeBase64(uint8Array).replace(/={1,2}$/, "");
+export function encodeUnpaddedBase64(uint8Array: Uint8Array): string {
+    return toBase64(uint8Array, { alphabet: "base64", omitPadding: true });
 }
 
 /**
@@ -58,8 +60,19 @@ export function encodeUnpaddedBase64(uint8Array: ArrayBuffer | Uint8Array): stri
  * @param uint8Array - The data to encode.
  * @returns The unpadded base64.
  */
-export function encodeUnpaddedBase64Url(uint8Array: ArrayBuffer | Uint8Array): string {
-    return encodeUnpaddedBase64(uint8Array).replace(/\+/g, "-").replace(/\//g, "_");
+export function encodeUnpaddedBase64Url(uint8Array: Uint8Array): string {
+    return toBase64(uint8Array, { alphabet: "base64url", omitPadding: true });
+}
+
+function fromBase64(base64: string, options: Uint8ArrayFromBase64Options): Uint8Array {
+    if (typeof Uint8Array.fromBase64 === "function") {
+        // Currently this is only supported in Firefox,
+        // but we match the options in the hope in the future we can rely on it for all environments.
+        // https://tc39.es/proposal-arraybuffer-base64/spec/#sec-uint8array.frombase64
+        return Uint8Array.fromBase64(base64, options);
+    }
+
+    return Uint8Array.from(atob(base64), (c) => c.charCodeAt(0));
 }
 
 /**
@@ -68,21 +81,6 @@ export function encodeUnpaddedBase64Url(uint8Array: ArrayBuffer | Uint8Array): s
  * @returns The decoded data.
  */
 export function decodeBase64(base64: string): Uint8Array {
-    // See encodeBase64 for a short treatise on base64 en/decoding in JS
-    if (typeof Buffer === "function") {
-        return Buffer.from(base64, "base64");
-    } else if (typeof atob === "function") {
-        const itFunc = function* (): Generator<number> {
-            const decoded = atob(
-                // built-in atob doesn't support base64url: convert so we support either
-                base64.replace(/-/g, "+").replace(/_/g, "/"),
-            );
-            for (let i = 0; i < decoded.length; ++i) {
-                yield decoded.charCodeAt(i);
-            }
-        };
-        return Uint8Array.from(itFunc());
-    } else {
-        throw new Error("No base64 impl found!");
-    }
+    // The function requires us to select an alphabet, but we don't know if base64url was used so we convert.
+    return fromBase64(base64.replace(/-/g, "+").replace(/_/g, "/"), { alphabet: "base64", lastChunkHandling: "loose" });
 }

src/client.ts

@@ -46,7 +46,6 @@ import { noUnsafeEventProps, QueryDict, replaceParam, safeSet, sleep } from "./u
 import { Direction, EventTimeline } from "./models/event-timeline.ts";
 import { IActionsObject, PushProcessor } from "./pushprocessor.ts";
 import { AutoDiscovery, AutoDiscoveryAction } from "./autodiscovery.ts";
-import * as olmlib from "./crypto/olmlib.ts";
 import { decodeBase64, encodeBase64, encodeUnpaddedBase64Url } from "./base64.ts";
 import { IExportedDevice as IExportedOlmDevice } from "./crypto/OlmDevice.ts";
 import { IOlmDevice } from "./crypto/algorithms/megolm.ts";
@@ -80,7 +79,6 @@ import {
     CryptoEventHandlerMap as LegacyCryptoEventHandlerMap,
     fixBackupKey,
     ICheckOwnCrossSigningTrustOpts,
-    ICryptoCallbacks,
     IRoomKeyRequestBody,
     isCryptoAvailable,
 } from "./crypto/index.ts";
@@ -229,6 +227,7 @@ import {
     ImportRoomKeysOpts,
     CryptoEvent,
     CryptoEventHandlerMap,
+    CryptoCallbacks,
 } from "./crypto-api/index.ts";
 import { DeviceInfoMap } from "./crypto/DeviceList.ts";
 import {
@@ -252,6 +251,9 @@ export type Store = IStore;
 export type ResetTimelineCallback = (roomId: string) => boolean;
 
 const SCROLLBACK_DELAY_MS = 3000;
+/**
+ * @deprecated Not supported for Rust Cryptography.
+ */
 export const CRYPTO_ENABLED: boolean = isCryptoAvailable();
 const TURN_CHECK_INTERVAL = 10 * 60 * 1000; // poll for turn credentials every 10 minutes
 
@@ -286,12 +288,16 @@ export interface ICreateClientOpts {
     store?: Store;
 
     /**
-     * A store to be used for end-to-end crypto session data. If not specified,
-     * end-to-end crypto will be disabled. The `createClient` helper will create
-     * a default store if needed. Calls the factory supplied to
+     * A store to be used for end-to-end crypto session data.
+     * The `createClient` helper will create a default store if needed. Calls the factory supplied to
      * {@link setCryptoStoreFactory} if unspecified; or if no factory has been
      * specified, uses a default implementation (indexeddb in the browser,
      * in-memory otherwise).
+     *
+     * This is only used for the legacy crypto implementation (as used by {@link MatrixClient#initLegacyCrypto}),
+     * but if you use the rust crypto implementation ({@link MatrixClient#initRustCrypto}) and the device
+     * previously used legacy crypto (so must be migrated), then this must still be provided, so that the
+     * data can be migrated from the legacy store.
      */
     cryptoStore?: CryptoStore;
 
@@ -383,7 +389,7 @@ export interface ICreateClientOpts {
      *
      * This must be set to the same value every time the client is initialised for the same device.
      *
-     * This is only used for the legacy crypto implementation (as used by {@link MatrixClient#initCrypto}),
+     * This is only used for the legacy crypto implementation (as used by {@link MatrixClient#initLegacyCrypto}),
      * but if you use the rust crypto implementation ({@link MatrixClient#initRustCrypto}) and the device
      * previously used legacy crypto (so must be migrated), then this must still be provided, so that the
      * data can be migrated from the legacy store.
@@ -433,7 +439,7 @@ export interface ICreateClientOpts {
     /**
      * Crypto callbacks provided by the application
      */
-    cryptoCallbacks?: ICryptoCallbacks;
+    cryptoCallbacks?: CryptoCallbacks;
 
     /**
      * Method to generate room names for empty rooms and rooms names based on membership.
@@ -1216,7 +1222,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     private readonly logger: Logger;
 
     public reEmitter = new TypedReEmitter<EmittedEvents, ClientEventHandlerMap>(this);
-    public olmVersion: [number, number, number] | null = null; // populated after initCrypto
+    public olmVersion: [number, number, number] | null = null; // populated after initLegacyCrypto
     public usingExternalCrypto = false;
     private _store!: Store;
     public deviceId: string | null;
@@ -1249,7 +1255,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     public crypto?: Crypto; // XXX: Intended private, used in code. Being replaced by cryptoBackend
 
     private cryptoBackend?: CryptoBackend; // one of crypto or rustCrypto
-    public cryptoCallbacks: ICryptoCallbacks; // XXX: Intended private, used in code.
+    public cryptoCallbacks: CryptoCallbacks; // XXX: Intended private, used in code.
     public callEventHandler?: CallEventHandler; // XXX: Intended private, used in code.
     public groupCallEventHandler?: GroupCallEventHandler;
     public supportsCallTransfer = false; // XXX: Intended private, used in code.
@@ -1269,6 +1275,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     protected isGuestAccount = false;
     protected ongoingScrollbacks: { [roomId: string]: { promise?: Promise<Room>; errorTs?: number } } = {};
     protected notifTimelineSet: EventTimelineSet | null = null;
+    /* @deprecated  */
     protected cryptoStore?: CryptoStore;
     protected verificationMethods?: string[];
     protected fallbackICEServerAllowed = false;
@@ -1598,7 +1605,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     /**
      * Try to rehydrate a device if available.  The client must have been
      * initialized with a `cryptoCallback.getDehydrationKey` option, and this
-     * function must be called before initCrypto and startClient are called.
+     * function must be called before initLegacyCrypto and startClient are called.
      *
      * @returns Promise which resolves to undefined if a device could not be dehydrated, or
      *     to the new device ID if the dehydration was successful.
@@ -1825,10 +1832,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns MXID for the logged-in user, or null if not logged in
      */
     public getUserId(): string | null {
-        if (this.credentials && this.credentials.userId) {
-            return this.credentials.userId;
-        }
-        return null;
+        return this.credentials?.userId ?? null;
     }
 
     /**
@@ -1850,7 +1854,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns Domain of this MXID
      */
     public getDomain(): string | null {
-        if (this.credentials && this.credentials.userId) {
+        if (this.credentials?.userId) {
             return this.credentials.userId.replace(/^.*?:/, "");
         }
         return null;
@@ -1861,10 +1865,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns The user ID localpart or null.
      */
     public getUserIdLocalpart(): string | null {
-        if (this.credentials && this.credentials.userId) {
-            return this.credentials.userId.split(":")[0].substring(1);
-        }
-        return null;
+        return this.credentials?.userId?.split(":")[0].substring(1) ?? null;
     }
 
     /**
@@ -2146,7 +2147,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      *
      * @deprecated libolm is deprecated. Prefer {@link initRustCrypto}.
      */
-    public async initCrypto(): Promise<void> {
+    public async initLegacyCrypto(): Promise<void> {
         if (!isCryptoAvailable()) {
             throw new Error(
                 `End-to-end encryption not supported in this js-sdk build: did ` +
@@ -2219,7 +2220,11 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     /**
      * Initialise support for end-to-end encryption in this client, using the rust matrix-sdk-crypto.
      *
-     * An alternative to {@link initCrypto}.
+     * An alternative to {@link initLegacyCrypto}.
+     *
+     * **WARNING**: the cryptography stack is not thread-safe. Having multiple `MatrixClient` instances connected to
+     * the same Indexed DB will cause data corruption and decryption failures. The application layer is responsible for
+     * ensuring that only one `MatrixClient` issue is instantiated at a time.
      *
      * @param args.useIndexedDB - True to use an indexeddb store, false to use an in-memory store. Defaults to 'true'.
      * @param args.storageKey - A key with which to encrypt the indexeddb store. If provided, it must be exactly
@@ -2316,7 +2321,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     /**
      * Access the crypto API for this client.
      *
-     * If end-to-end encryption has been enabled for this client (via {@link initCrypto} or {@link initRustCrypto}),
+     * If end-to-end encryption has been enabled for this client (via {@link initLegacyCrypto} or {@link initRustCrypto}),
      * returns an object giving access to the crypto API. Otherwise, returns `undefined`.
      */
     public getCrypto(): CryptoApi | undefined {
@@ -2425,6 +2430,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      *
      * @remarks
      * Fires {@link CryptoEvent#DeviceVerificationChanged}
+     *
+     * @deprecated Not supported for Rust Cryptography.
      */
     public setDeviceVerified(userId: string, deviceId: string, verified = true): Promise<void> {
         const prom = this.setDeviceVerification(userId, deviceId, verified, null, null);
@@ -3152,6 +3159,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      *
      * @returns true if the sender of this event has been verified using
      * {@link MatrixClient#setDeviceVerified}.
+     *
+     * @deprecated Not supported for Rust Cryptography.
      */
     public async isEventSenderVerified(event: MatrixEvent): Promise<boolean> {
         const device = await this.getEventSenderDeviceInfo(event);
@@ -3352,7 +3361,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      *
      * @returns Information object from API, or null if no backup is present on the server.
      *
-     * @deprecated Prefer {@link CryptoApi.getActiveSessionBackupVersion}.
+     * @deprecated Prefer {@link CryptoApi.getKeyBackupInfo}.
      */
     public async getKeyBackupVersion(): Promise<IKeyBackupInfo | null> {
         let res: IKeyBackupInfo;
@@ -3698,6 +3707,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @param opts - Optional params such as callbacks
      * @returns Status of restoration with `total` and `imported`
      * key counts.
+     *
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackupWithPassphrase | `CryptoApi.restoreKeyBackupWithPassphrase`}.
      */
     public async restoreKeyBackupWithPassword(
         password: string,
@@ -3706,6 +3717,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         backupInfo: IKeyBackupInfo,
         opts: IKeyBackupRestoreOpts,
     ): Promise<IKeyBackupRestoreResult>;
+    /**
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackupWithPassphrase | `CryptoApi.restoreKeyBackupWithPassphrase`}.
+     */
     public async restoreKeyBackupWithPassword(
         password: string,
         targetRoomId: string,
@@ -3713,6 +3727,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         backupInfo: IKeyBackupInfo,
         opts: IKeyBackupRestoreOpts,
     ): Promise<IKeyBackupRestoreResult>;
+    /**
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackupWithPassphrase | `CryptoApi.restoreKeyBackupWithPassphrase`}.
+     */
     public async restoreKeyBackupWithPassword(
         password: string,
         targetRoomId: string,
@@ -3720,6 +3737,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         backupInfo: IKeyBackupInfo,
         opts: IKeyBackupRestoreOpts,
     ): Promise<IKeyBackupRestoreResult>;
+    /**
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackupWithPassphrase | `CryptoApi.restoreKeyBackupWithPassphrase`}.
+     */
     public async restoreKeyBackupWithPassword(
         password: string,
         targetRoomId: string | undefined,
@@ -3743,6 +3763,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @param opts - Optional params such as callbacks
      * @returns Status of restoration with `total` and `imported`
      * key counts.
+     *
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackup | `CryptoApi.restoreKeyBackup`}.
      */
     public async restoreKeyBackupWithSecretStorage(
         backupInfo: IKeyBackupInfo,
@@ -3780,6 +3802,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
      * @returns Status of restoration with `total` and `imported`
      * key counts.
+     *
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackup | `CryptoApi.restoreKeyBackup`}.
      */
     public restoreKeyBackupWithRecoveryKey(
         recoveryKey: string,
@@ -3788,6 +3812,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         backupInfo: IKeyBackupInfo,
         opts?: IKeyBackupRestoreOpts,
     ): Promise<IKeyBackupRestoreResult>;
+    /**
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackup | `CryptoApi.restoreKeyBackup`}.
+     */
     public restoreKeyBackupWithRecoveryKey(
         recoveryKey: string,
         targetRoomId: string,
@@ -3795,6 +3822,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         backupInfo: IKeyBackupInfo,
         opts?: IKeyBackupRestoreOpts,
     ): Promise<IKeyBackupRestoreResult>;
+    /**
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackup | `CryptoApi.restoreKeyBackup`}.
+     */
     public restoreKeyBackupWithRecoveryKey(
         recoveryKey: string,
         targetRoomId: string,
@@ -3802,6 +3832,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         backupInfo: IKeyBackupInfo,
         opts?: IKeyBackupRestoreOpts,
     ): Promise<IKeyBackupRestoreResult>;
+    /**
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackup | `CryptoApi.restoreKeyBackup`}.
+     */
     public restoreKeyBackupWithRecoveryKey(
         recoveryKey: string,
         targetRoomId: string | undefined,
@@ -3813,24 +3846,42 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         return this.restoreKeyBackup(privKey, targetRoomId!, targetSessionId!, backupInfo, opts);
     }
 
+    /**
+     * Restore from an existing key backup via a private key stored locally
+     * @param targetRoomId
+     * @param targetSessionId
+     * @param backupInfo
+     * @param opts
+     *
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackup | `CryptoApi.restoreKeyBackup`}.
+     */
     public async restoreKeyBackupWithCache(
         targetRoomId: undefined,
         targetSessionId: undefined,
         backupInfo: IKeyBackupInfo,
         opts?: IKeyBackupRestoreOpts,
     ): Promise<IKeyBackupRestoreResult>;
+    /**
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackup | `CryptoApi.restoreKeyBackup`}.
+     */
     public async restoreKeyBackupWithCache(
         targetRoomId: string,
         targetSessionId: undefined,
         backupInfo: IKeyBackupInfo,
         opts?: IKeyBackupRestoreOpts,
     ): Promise<IKeyBackupRestoreResult>;
+    /**
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackup | `CryptoApi.restoreKeyBackup`}.
+     */
     public async restoreKeyBackupWithCache(
         targetRoomId: string,
         targetSessionId: string,
         backupInfo: IKeyBackupInfo,
         opts?: IKeyBackupRestoreOpts,
     ): Promise<IKeyBackupRestoreResult>;
+    /**
+     * @deprecated Prefer {@link CryptoApi.restoreKeyBackup | `CryptoApi.restoreKeyBackup`}.
+     */
     public async restoreKeyBackupWithCache(
         targetRoomId: string | undefined,
         targetSessionId: string | undefined,
@@ -3848,28 +3899,28 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     }
 
     private async restoreKeyBackup(
-        privKey: ArrayLike<number>,
+        privKey: Uint8Array,
         targetRoomId: undefined,
         targetSessionId: undefined,
         backupInfo: IKeyBackupInfo,
         opts?: IKeyBackupRestoreOpts,
     ): Promise<IKeyBackupRestoreResult>;
     private async restoreKeyBackup(
-        privKey: ArrayLike<number>,
+        privKey: Uint8Array,
         targetRoomId: string,
         targetSessionId: undefined,
         backupInfo: IKeyBackupInfo,
         opts?: IKeyBackupRestoreOpts,
     ): Promise<IKeyBackupRestoreResult>;
     private async restoreKeyBackup(
-        privKey: ArrayLike<number>,
+        privKey: Uint8Array,
         targetRoomId: string,
         targetSessionId: string,
         backupInfo: IKeyBackupInfo,
         opts?: IKeyBackupRestoreOpts,
     ): Promise<IKeyBackupRestoreResult>;
     private async restoreKeyBackup(
-        privKey: ArrayLike<number>,
+        privKey: Uint8Array,
         targetRoomId: string | undefined,
         targetSessionId: string | undefined,
         backupInfo: IKeyBackupInfo,
@@ -4260,7 +4311,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      */
     public getIgnoredUsers(): string[] {
         const event = this.getAccountData("m.ignored_user_list");
-        if (!event || !event.getContent() || !event.getContent()["ignored_users"]) return [];
+        if (!event?.getContent()["ignored_users"]) return [];
         return Object.keys(event.getContent()["ignored_users"]);
     }
 
@@ -6087,7 +6138,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                         room.partitionThreadedEvents(matrixEvents);
 
                     this.processAggregatedTimelineEvents(room, timelineEvents);
-                    room.addEventsToTimeline(timelineEvents, true, room.getLiveTimeline());
+                    room.addEventsToTimeline(timelineEvents, true, true, room.getLiveTimeline());
                     this.processThreadEvents(room, threadedEvents, true);
                     unknownRelations.forEach((event) => room.relations.aggregateChildEvent(event));
 
@@ -6199,7 +6250,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         }
 
         const [timelineEvents, threadedEvents, unknownRelations] = timelineSet.room.partitionThreadedEvents(events);
-        timelineSet.addEventsToTimeline(timelineEvents, true, timeline, res.start);
+        timelineSet.addEventsToTimeline(timelineEvents, true, false, timeline, res.start);
         // The target event is not in a thread but process the contextual events, so we can show any threads around it.
         this.processThreadEvents(timelineSet.room, threadedEvents, true);
         this.processAggregatedTimelineEvents(timelineSet.room, timelineEvents);
@@ -6293,10 +6344,10 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                     timeline.initialiseState(res.state.map(mapper));
                 }
 
-                timelineSet.addEventsToTimeline(events, true, timeline, resNewer.next_batch);
+                timelineSet.addEventsToTimeline(events, true, false, timeline, resNewer.next_batch);
                 if (!resOlder.next_batch) {
                     const originalEvent = await this.fetchRoomEvent(timelineSet.room.roomId, thread.id);
-                    timelineSet.addEventsToTimeline([mapper(originalEvent)], true, timeline, null);
+                    timelineSet.addEventsToTimeline([mapper(originalEvent)], true, false, timeline, null);
                 }
                 timeline.setPaginationToken(resOlder.next_batch ?? null, Direction.Backward);
                 timeline.setPaginationToken(resNewer.next_batch ?? null, Direction.Forward);
@@ -6350,10 +6401,10 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                 const timeline = timelineSet.getLiveTimeline();
                 timeline.getState(EventTimeline.BACKWARDS)!.setUnknownStateEvents(res.state.map(mapper));
 
-                timelineSet.addEventsToTimeline(events, true, timeline, null);
+                timelineSet.addEventsToTimeline(events, true, false, timeline, null);
                 if (!resOlder.next_batch) {
                     const originalEvent = await this.fetchRoomEvent(timelineSet.room.roomId, thread.id);
-                    timelineSet.addEventsToTimeline([mapper(originalEvent)], true, timeline, null);
+                    timelineSet.addEventsToTimeline([mapper(originalEvent)], true, false, timeline, null);
                 }
                 timeline.setPaginationToken(resOlder.next_batch ?? null, Direction.Backward);
                 timeline.setPaginationToken(null, Direction.Forward);
@@ -6616,7 +6667,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                     // No need to partition events for threads here, everything lives
                     // in the notification timeline set
                     const timelineSet = eventTimeline.getTimelineSet();
-                    timelineSet.addEventsToTimeline(matrixEvents, backwards, eventTimeline, token);
+                    timelineSet.addEventsToTimeline(matrixEvents, backwards, false, eventTimeline, token);
                     this.processAggregatedTimelineEvents(timelineSet.room, matrixEvents);
 
                     // if we've hit the end of the timeline, we need to stop trying to
@@ -6659,7 +6710,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                     const matrixEvents = res.chunk.filter(noUnsafeEventProps).map(this.getEventMapper());
 
                     const timelineSet = eventTimeline.getTimelineSet();
-                    timelineSet.addEventsToTimeline(matrixEvents, backwards, eventTimeline, token);
+                    timelineSet.addEventsToTimeline(matrixEvents, backwards, false, eventTimeline, token);
                     this.processAggregatedTimelineEvents(room, matrixEvents);
                     this.processThreadRoots(room, matrixEvents, backwards);
 
@@ -6707,12 +6758,12 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                     const newToken = res.next_batch;
 
                     const timelineSet = eventTimeline.getTimelineSet();
-                    timelineSet.addEventsToTimeline(matrixEvents, backwards, eventTimeline, newToken ?? null);
+                    timelineSet.addEventsToTimeline(matrixEvents, backwards, false, eventTimeline, newToken ?? null);
                     if (!newToken && backwards) {
                         const originalEvent =
                             thread.rootEvent ??
                             mapper(await this.fetchRoomEvent(eventTimeline.getRoomId() ?? "", thread.id));
-                        timelineSet.addEventsToTimeline([originalEvent], true, eventTimeline, null);
+                        timelineSet.addEventsToTimeline([originalEvent], true, false, eventTimeline, null);
                     }
                     this.processAggregatedTimelineEvents(timelineSet.room, matrixEvents);
 
@@ -6751,7 +6802,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
                     const timelineSet = eventTimeline.getTimelineSet();
                     const [timelineEvents, , unknownRelations] = room.partitionThreadedEvents(matrixEvents);
-                    timelineSet.addEventsToTimeline(timelineEvents, backwards, eventTimeline, token);
+                    timelineSet.addEventsToTimeline(timelineEvents, backwards, false, eventTimeline, token);
                     this.processAggregatedTimelineEvents(room, timelineEvents);
                     this.processThreadRoots(
                         room,
@@ -10066,7 +10117,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                     type: EventType.RoomEncryption,
                     state_key: "",
                     content: {
-                        algorithm: olmlib.MEGOLM_ALGORITHM,
+                        algorithm: "m.megolm.v1.aes-sha2",
                     },
                 },
             ],

src/common-crypto/CryptoBackend.ts

@@ -78,6 +78,7 @@ export interface CryptoBackend extends SyncCryptoCallbacks, CryptoApi {
      * Get information about the encryption of an event
      *
      * @param event - event to be checked
+     * @deprecated Use {@link CryptoApi#getEncryptionInfoForEvent} instead
      */
     getEventEncryptionInfo(event: MatrixEvent): IEncryptedEventInfo;
 
@@ -107,7 +108,7 @@ export interface CryptoBackend extends SyncCryptoCallbacks, CryptoApi {
      * @param backupInfo - The backup information
      * @param privKey - The private decryption key.
      */
-    getBackupDecryptor(backupInfo: KeyBackupInfo, privKey: ArrayLike<number>): Promise<BackupDecryptor>;
+    getBackupDecryptor(backupInfo: KeyBackupInfo, privKey: Uint8Array): Promise<BackupDecryptor>;
 
     /**
      * Import a list of room keys restored from backup

src/crypto-api/CryptoEventHandlerMap.ts

@@ -29,4 +29,5 @@ export type CryptoEventHandlerMap = {
     [CryptoEvent.KeysChanged]: (data: {}) => void;
     [CryptoEvent.WillUpdateDevices]: (users: string[], initialFetch: boolean) => void;
     [CryptoEvent.DevicesUpdated]: (users: string[], initialFetch: boolean) => void;
+    [CryptoEvent.LegacyCryptoStoreMigrationProgress]: (progress: number, total: number) => void;
 } & RustBackupCryptoEventMap;

src/crypto-api/index.ts

@@ -22,7 +22,13 @@ import { DeviceMap } from "../models/device.ts";
 import { UIAuthCallback } from "../interactive-auth.ts";
 import { PassphraseInfo, SecretStorageCallbacks, SecretStorageKeyDescription } from "../secret-storage.ts";
 import { VerificationRequest } from "./verification.ts";
-import { BackupTrustInfo, KeyBackupCheck, KeyBackupInfo } from "./keybackup.ts";
+import {
+    BackupTrustInfo,
+    KeyBackupCheck,
+    KeyBackupInfo,
+    KeyBackupRestoreOpts,
+    KeyBackupRestoreResult,
+} from "./keybackup.ts";
 import { ISignatures } from "../@types/signed.ts";
 import { MatrixEvent } from "../models/event.ts";
 
@@ -502,6 +508,18 @@ export interface CryptoApi {
      */
     storeSessionBackupPrivateKey(key: Uint8Array, version: string): Promise<void>;
 
+    /**
+     * Attempt to fetch the backup decryption key from secret storage.
+     *
+     * If the key is found in secret storage, checks it against the latest backup on the server;
+     * if they match, stores the key in the crypto store by calling {@link storeSessionBackupPrivateKey},
+     * which enables automatic restore of individual keys when an Unable-to-decrypt error is encountered.
+     *
+     * If we are unable to fetch the key from secret storage, there is no backup on the server, or the key
+     * does not match, throws an exception.
+     */
+    loadSessionBackupPrivateKeyFromSecretStorage(): Promise<void>;
+
     /**
      * Get the current status of key backup.
      *
@@ -516,6 +534,18 @@ export interface CryptoApi {
      */
     isKeyBackupTrusted(info: KeyBackupInfo): Promise<BackupTrustInfo>;
 
+    /**
+     * Return the details of the latest backup on the server, when we last checked.
+     *
+     * This normally returns a cached value, but if we haven't yet made a request to the server, it will fire one off.
+     * It will always return the details of the active backup if key backup is enabled.
+     *
+     * Return null if there is no backup.
+     *
+     * @returns the key backup information
+     */
+    getKeyBackupInfo(): Promise<KeyBackupInfo | null>;
+
     /**
      * Force a re-check of the key backup and enable/disable it as appropriate.
      *
@@ -545,6 +575,36 @@ export interface CryptoApi {
      */
     deleteKeyBackupVersion(version: string): Promise<void>;
 
+    /**
+     * Download and restore the full key backup from the homeserver.
+     *
+     * Before calling this method, a decryption key, and the backup version to restore,
+     * must have been saved in the crypto store. This happens in one of the following ways:
+     *
+     * - When a new backup version is created with {@link CryptoApi.resetKeyBackup}, a new key is created and cached.
+     * - The key can be loaded from secret storage with {@link CryptoApi.loadSessionBackupPrivateKeyFromSecretStorage}.
+     * - The key can be received from another device via secret sharing, typically as part of the interactive verification flow.
+     * - The key and backup version can also be set explicitly via {@link CryptoApi.storeSessionBackupPrivateKey},
+     *   though this is not expected to be a common operation.
+     *
+     * Warning: the full key backup may be quite large, so this operation may take several hours to complete.
+     * Use of {@link KeyBackupRestoreOpts.progressCallback} is recommended.
+     *
+     * @param opts
+     */
+    restoreKeyBackup(opts?: KeyBackupRestoreOpts): Promise<KeyBackupRestoreResult>;
+
+    /**
+     * Restores a key backup using a passphrase.
+     * The decoded key (derived from the passphrase) is stored locally by calling {@link CryptoApi#storeSessionBackupPrivateKey}.
+     *
+     * @param passphrase - The passphrase to use to restore the key backup.
+     * @param opts
+     *
+     * @deprecated Deriving a backup key from a passphrase is not part of the matrix spec. Instead, a random key is generated and stored/shared via 4S.
+     */
+    restoreKeyBackupWithPassphrase(passphrase: string, opts?: KeyBackupRestoreOpts): Promise<KeyBackupRestoreResult>;
+
     ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     //
     // Dehydrated devices
@@ -886,8 +946,8 @@ export class DeviceVerificationStatus {
 
 /**
  * Room key import progress report.
- * Used when calling {@link CryptoApi#importRoomKeys} or
- * {@link CryptoApi#importRoomKeysAsJson} as the parameter of
+ * Used when calling {@link CryptoApi#importRoomKeys},
+ * {@link CryptoApi#importRoomKeysAsJson} or {@link CryptoApi#restoreKeyBackup} as the parameter of
  * the progressCallback. Used to display feedback.
  */
 export interface ImportRoomKeyProgressData {
@@ -1097,6 +1157,16 @@ export enum EventShieldReason {
      * decryption keys.
      */
     MISMATCHED_SENDER_KEY,
+
+    /**
+     * The event was sent unencrypted in an encrypted room.
+     */
+    SENT_IN_CLEAR,
+
+    /**
+     * The sender was previously verified but changed their identity.
+     */
+    VERIFICATION_VIOLATION,
 }
 
 /** The result of a call to {@link CryptoApi.getOwnDeviceKeys} */

src/crypto-api/keybackup.ts

@@ -16,6 +16,7 @@ limitations under the License.
 
 import { ISigned } from "../@types/signed.ts";
 import { AESEncryptedSecretStoragePayload } from "../@types/AESEncryptedSecretStoragePayload.ts";
+import { ImportRoomKeyProgressData } from "./index.ts";
 
 export interface Curve25519AuthData {
     public_key: string;
@@ -87,3 +88,28 @@ export interface KeyBackupSession<T = Curve25519SessionData | AESEncryptedSecret
 export interface KeyBackupRoomSessions {
     [sessionId: string]: KeyBackupSession;
 }
+
+/**
+ * Extra parameters for {@link CryptoApi.restoreKeyBackup} and {@link CryptoApi.restoreKeyBackupWithPassphrase}.
+ */
+export interface KeyBackupRestoreOpts {
+    /**
+     * A callback which, if defined, will be called periodically to report ongoing progress of the backup restore process.
+     * @param progress
+     */
+    progressCallback?: (progress: ImportRoomKeyProgressData) => void;
+}
+
+/**
+ * The result of {@link CryptoApi.restoreKeyBackup}.
+ */
+export interface KeyBackupRestoreResult {
+    /**
+     * The total number of keys that were found in the backup.
+     */
+    total: number;
+    /**
+     * The number of keys that were imported.
+     */
+    imported: number;
+}

src/crypto-api/recovery-key.ts

@@ -26,7 +26,7 @@ const KEY_SIZE = 32;
  * @param key
  */
 export function encodeRecoveryKey(key: ArrayLike<number>): string | undefined {
-    const buf = Buffer.alloc(OLM_RECOVERY_KEY_PREFIX.length + key.length + 1);
+    const buf = new Uint8Array(OLM_RECOVERY_KEY_PREFIX.length + key.length + 1);
     buf.set(OLM_RECOVERY_KEY_PREFIX, 0);
     buf.set(key, OLM_RECOVERY_KEY_PREFIX.length);
 

src/crypto-api/verification.ts

@@ -155,7 +155,7 @@ export interface VerificationRequest
      * @param qrCodeData - the decoded QR code.
      * @returns A verifier; call `.verify()` on it to wait for the other side to complete the verification flow.
      */
-    scanQRCode(qrCodeData: Uint8Array): Promise<Verifier>;
+    scanQRCode(qrCodeData: Uint8ClampedArray): Promise<Verifier>;
 
     /**
      * The verifier which is doing the actual verification, once the method has been established.
@@ -170,7 +170,7 @@ export interface VerificationRequest
      *
      * @deprecated Not supported in Rust Crypto. Use {@link VerificationRequest#generateQRCode} instead.
      */
-    getQRCodeBytes(): Buffer | undefined;
+    getQRCodeBytes(): Uint8ClampedArray | undefined;
 
     /**
      * Generate the data for a QR code allowing the other device to verify this one, if it supports it.
@@ -178,7 +178,7 @@ export interface VerificationRequest
      * Only returns data once `phase` is {@link VerificationPhase.Ready} and the other party can scan a QR code;
      * otherwise returns `undefined`.
      */
-    generateQRCode(): Promise<Buffer | undefined>;
+    generateQRCode(): Promise<Uint8ClampedArray | undefined>;
 
     /**
      * If this request has been cancelled, the cancellation code (e.g `m.user`) which is responsible for cancelling

src/crypto/EncryptionSetup.ts

@@ -106,7 +106,7 @@ export class EncryptionSetupBuilder {
         if (!this.keySignatures) {
             this.keySignatures = {};
         }
-        const userSignatures = this.keySignatures[userId] || {};
+        const userSignatures = this.keySignatures[userId] ?? {};
         this.keySignatures[userId] = userSignatures;
         userSignatures[deviceId] = signature;
     }

src/crypto/dehydration.ts

@@ -27,8 +27,8 @@ import decryptAESSecretStorageItem from "../utils/decryptAESSecretStorageItem.ts
 import encryptAESSecretStorageItem from "../utils/encryptAESSecretStorageItem.ts";
 
 export interface IDehydratedDevice {
-    device_id: string; // eslint-disable-line camelcase
-    device_data: SecretStorageKeyDescription & {
+    device_id?: string; // eslint-disable-line camelcase
+    device_data?: SecretStorageKeyDescription & {
         // eslint-disable-line camelcase
         algorithm: string;
         account: string; // pickle
@@ -90,7 +90,7 @@ export class DehydrationManager {
     }
 
     public async setKey(
-        key: Uint8Array,
+        key?: Uint8Array,
         keyInfo: { [props: string]: any } = {},
         deviceDisplayName?: string,
     ): Promise<boolean | undefined> {

src/crypto/index.ts

@@ -102,6 +102,8 @@ import {
     OwnDeviceKeys,
     CryptoEvent as CryptoApiCryptoEvent,
     CryptoEventHandlerMap as CryptoApiCryptoEventHandlerMap,
+    KeyBackupRestoreResult,
+    KeyBackupRestoreOpts,
 } from "../crypto-api/index.ts";
 import { Device, DeviceMap } from "../models/device.ts";
 import { deviceInfoToDevice } from "./device-converter.ts";
@@ -324,8 +326,6 @@ export type CryptoEventHandlerMap = CryptoApiCryptoEventHandlerMap & {
      */
     [CryptoEvent.Warning]: (type: string) => void;
     [CryptoEvent.UserCrossSigningUpdated]: (userId: string) => void;
-
-    [CryptoEvent.LegacyCryptoStoreMigrationProgress]: (progress: number, total: number) => void;
 };
 
 export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap> implements CryptoBackend {
@@ -1306,6 +1306,13 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
         });
     }
 
+    /**
+     * Implementation of {@link Crypto.loadSessionBackupPrivateKeyFromSecretStorage}.
+     */
+    public loadSessionBackupPrivateKeyFromSecretStorage(): Promise<void> {
+        throw new Error("Not implmeented");
+    }
+
     /**
      * Get the current status of key backup.
      *
@@ -1318,6 +1325,13 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
         return null;
     }
 
+    /**
+     * Implementation of {@link Crypto.CryptoApi#getKeyBackupInfo}.
+     */
+    public async getKeyBackupInfo(): Promise<KeyBackupInfo | null> {
+        throw new Error("Not implemented");
+    }
+
     /**
      * Determine if a key backup can be trusted.
      *
@@ -1832,7 +1846,7 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
     /**
      * Implementation of {@link CryptoBackend#getBackupDecryptor}.
      */
-    public async getBackupDecryptor(backupInfo: KeyBackupInfo, privKey: ArrayLike<number>): Promise<BackupDecryptor> {
+    public async getBackupDecryptor(backupInfo: KeyBackupInfo, privKey: Uint8Array): Promise<BackupDecryptor> {
         if (!(privKey instanceof Uint8Array)) {
             throw new Error(`getBackupDecryptor expects Uint8Array`);
         }
@@ -4308,6 +4322,23 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
     public async startDehydration(createNewKey?: boolean): Promise<void> {
         throw new Error("Not implemented");
     }
+
+    /**
+     * Stub function -- restoreKeyBackup is not implemented here, so throw error
+     */
+    public restoreKeyBackup(opts: KeyBackupRestoreOpts): Promise<KeyBackupRestoreResult> {
+        throw new Error("Not implemented");
+    }
+
+    /**
+     * Stub function -- restoreKeyBackupWithPassphrase is not implemented here, so throw error
+     */
+    public restoreKeyBackupWithPassphrase(
+        passphrase: string,
+        opts: KeyBackupRestoreOpts,
+    ): Promise<KeyBackupRestoreResult> {
+        throw new Error("Not implemented");
+    }
 }
 
 /**

src/crypto/store/localStorage-crypto-store.ts

@@ -162,7 +162,7 @@ export class LocalStorageCryptoStore extends MemoryCryptoStore implements Crypto
         func: (session: ISessionInfo) => void,
     ): void {
         const sessions = this._getEndToEndSessions(deviceKey);
-        func(sessions[sessionId] || {});
+        func(sessions[sessionId] ?? {});
     }
 
     public getEndToEndSessions(
@@ -170,7 +170,7 @@ export class LocalStorageCryptoStore extends MemoryCryptoStore implements Crypto
         txn: unknown,
         func: (sessions: { [sessionId: string]: ISessionInfo }) => void,
     ): void {
-        func(this._getEndToEndSessions(deviceKey) || {});
+        func(this._getEndToEndSessions(deviceKey) ?? {});
     }
 
     public getAllEndToEndSessions(txn: unknown, func: (session: ISessionInfo) => void): void {

src/crypto/verification/request/VerificationRequest.ts

@@ -281,8 +281,9 @@ export class VerificationRequest<C extends IVerificationChannel = IVerificationC
      *
      * @deprecated Prefer `generateQRCode`.
      */
-    public getQRCodeBytes(): Buffer | undefined {
-        return this._qrCodeData?.getBuffer();
+    public getQRCodeBytes(): Uint8ClampedArray | undefined {
+        if (!this._qrCodeData) return;
+        return new Uint8ClampedArray(this._qrCodeData.getBuffer());
     }
 
     /**
@@ -291,7 +292,7 @@ export class VerificationRequest<C extends IVerificationChannel = IVerificationC
      * Only returns data once `phase` is `Ready` and the other party can scan a QR code;
      * otherwise returns `undefined`.
      */
-    public async generateQRCode(): Promise<Buffer | undefined> {
+    public async generateQRCode(): Promise<Uint8ClampedArray | undefined> {
         return this.getQRCodeBytes();
     }
 
@@ -478,7 +479,7 @@ export class VerificationRequest<C extends IVerificationChannel = IVerificationC
         return verifier;
     }
 
-    public scanQRCode(qrCodeData: Uint8Array): Promise<Verifier> {
+    public scanQRCode(qrCodeData: Uint8ClampedArray): Promise<Verifier> {
         throw new Error("QR code scanning not supported by legacy crypto");
     }
 

src/digest.ts

@@ -18,11 +18,11 @@ limitations under the License.
  * Computes a SHA-256 hash of a string (after utf-8 encoding) and returns it as an ArrayBuffer.
  *
  * @param plaintext The string to hash
- * @returns An ArrayBuffer containing the SHA-256 hash of the input string
+ * @returns An Uint8Array containing the SHA-256 hash of the input string
  * @throws If the subtle crypto API is not available, for example if the code is running
  *         in a web page with an insecure context (eg. served over plain HTTP).
  */
-export async function sha256(plaintext: string): Promise<ArrayBuffer> {
+export async function sha256(plaintext: string): Promise<Uint8Array> {
     if (!globalThis.crypto.subtle) {
         throw new Error("Crypto.subtle is not available: insecure context?");
     }
@@ -30,5 +30,5 @@ export async function sha256(plaintext: string): Promise<ArrayBuffer> {
 
     const digest = await globalThis.crypto.subtle.digest("SHA-256", utf8);
 
-    return digest;
+    return new Uint8Array(digest);
 }

src/embedded.ts

@@ -57,6 +57,7 @@ import { ToDeviceBatch, ToDevicePayload } from "./models/ToDeviceMessage.ts";
 import { DeviceInfo } from "./crypto/deviceinfo.ts";
 import { IOlmDevice } from "./crypto/algorithms/megolm.ts";
 import { MapWithDefault, recursiveMapToObject } from "./utils.ts";
+import { TypedEventEmitter } from "./matrix.ts";
 
 interface IStateEventRequest {
     eventType: string;
@@ -123,6 +124,10 @@ export interface ICapabilities {
     updateDelayedEvents?: boolean;
 }
 
+export enum RoomWidgetClientEvent {
+    PendingEventsChanged = "PendingEvent.pendingEventsChanged",
+}
+export type EventHandlerMap = { [RoomWidgetClientEvent.PendingEventsChanged]: () => void };
 /**
  * A MatrixClient that routes its requests through the widget API instead of the
  * real CS API.
@@ -134,6 +139,9 @@ export class RoomWidgetClient extends MatrixClient {
     private lifecycle?: AbortController;
     private syncState: SyncState | null = null;
 
+    private pendingSendingEventsTxId: { type: string; id: string | undefined; txId: string }[] = [];
+    private eventEmitter = new TypedEventEmitter<keyof EventHandlerMap, EventHandlerMap>();
+
     /**
      *
      * @param widgetApi - The widget api to use for communication.
@@ -276,7 +284,13 @@ export class RoomWidgetClient extends MatrixClient {
                 const rawEvents = await this.widgetApi.readStateEvents(eventType, undefined, stateKey, [this.roomId]);
                 const events = rawEvents.map((rawEvent) => new MatrixEvent(rawEvent as Partial<IEvent>));
 
-                await this.syncApi!.injectRoomEvents(this.room!, [], events);
+                if (this.syncApi instanceof SyncApi) {
+                    // Passing undefined for `stateAfterEventList` allows will make `injectRoomEvents` run in legacy mode
+                    // -> state events in `timelineEventList` will update the state.
+                    await this.syncApi.injectRoomEvents(this.room!, undefined, events);
+                } else {
+                    await this.syncApi!.injectRoomEvents(this.room!, events); // Sliding Sync
+                }
                 events.forEach((event) => {
                     this.emit(ClientEvent.Event, event);
                     logger.info(`Backfilled event ${event.getId()} ${event.getType()} ${event.getStateKey()}`);
@@ -330,6 +344,8 @@ export class RoomWidgetClient extends MatrixClient {
         const content = event.event.redacts
             ? { ...event.getContent(), redacts: event.event.redacts }
             : event.getContent();
+
+        // Delayed event special case.
         if (delayOpts) {
             // TODO: updatePendingEvent for delayed events?
             const response = await this.widgetApi.sendRoomEvent(
@@ -342,6 +358,10 @@ export class RoomWidgetClient extends MatrixClient {
             return this.validateSendDelayedEventResponse(response);
         }
 
+        const txId = event.getTxnId();
+        // Add the txnId to the pending list (still with unknown evID)
+        if (txId) this.pendingSendingEventsTxId.push({ type: event.getType(), id: undefined, txId });
+
         let response: ISendEventFromWidgetResponseData;
         try {
             response = await this.widgetApi.sendRoomEvent(event.getType(), content, room.roomId);
@@ -349,9 +369,15 @@ export class RoomWidgetClient extends MatrixClient {
             this.updatePendingEventStatus(room, event, EventStatus.NOT_SENT);
             throw e;
         }
-
         // This also checks for an event id on the response
         room.updatePendingEvent(event, EventStatus.SENT, response.event_id);
+
+        // Update the pending events list with the eventId
+        this.pendingSendingEventsTxId.forEach((p) => {
+            if (p.txId === txId) p.id = response.event_id;
+        });
+        this.eventEmitter.emit(RoomWidgetClientEvent.PendingEventsChanged);
+
         return { event_id: response.event_id! };
     }
 
@@ -495,6 +521,48 @@ export class RoomWidgetClient extends MatrixClient {
         await this.widgetApi.transport.reply<IWidgetApiAcknowledgeResponseData>(ev.detail, {});
     }
 
+    private updateTxId = async (event: MatrixEvent): Promise<void> => {
+        // We update the txId for remote echos that originate from this client.
+        // This happens with the help of `pendingSendingEventsTxId` where we store all events that are currently sending
+        // with their widget txId and once ready the final evId.
+        if (
+            // This could theoretically be an event send by this device
+            // In that case we need to update the txId of the event because the embedded client/widget
+            // knows this event with a different transaction Id than what was used by the host client.
+            event.getSender() === this.getUserId() &&
+            // We optimize by not blocking events from types that we have not send
+            // with this client.
+            this.pendingSendingEventsTxId.some((p) => event.getType() === p.type)
+        ) {
+            // Compare by event Id if we have a matching pending event where we know the txId.
+            let matchingTxId = this.pendingSendingEventsTxId.find((p) => p.id === event.getId())?.txId;
+            // Block any further processing of this event until we have received the sending response.
+            // -> until we know the event id.
+            // -> until we have not pending events anymore.
+            while (!matchingTxId && this.pendingSendingEventsTxId.length > 0) {
+                // Recheck whenever the PendingEventsChanged
+                await new Promise<void>((resolve) =>
+                    this.eventEmitter.once(RoomWidgetClientEvent.PendingEventsChanged, () => resolve()),
+                );
+                matchingTxId = this.pendingSendingEventsTxId.find((p) => p.id === event.getId())?.txId;
+            }
+
+            // We found the correct txId: we update the event and delete the entry of the pending events.
+            if (matchingTxId) {
+                event.setTxnId(matchingTxId);
+                event.setUnsigned({ ...event.getUnsigned(), transaction_id: matchingTxId });
+            }
+            this.pendingSendingEventsTxId = this.pendingSendingEventsTxId.filter((p) => p.id !== event.getId());
+
+            // Emit once there are no pending events anymore to release all other events that got
+            // awaited in the `while (!matchingTxId && this.pendingSendingEventsTxId.length > 0)` loop
+            // but are not send by this client.
+            if (this.pendingSendingEventsTxId.length === 0) {
+                this.eventEmitter.emit(RoomWidgetClientEvent.PendingEventsChanged);
+            }
+        }
+    };
+
     private onEvent = async (ev: CustomEvent<ISendEventToWidgetActionRequest>): Promise<void> => {
         ev.preventDefault();
 
@@ -502,7 +570,37 @@ export class RoomWidgetClient extends MatrixClient {
         // send us events from other rooms if this widget is always on screen
         if (ev.detail.data.room_id === this.roomId) {
             const event = new MatrixEvent(ev.detail.data as Partial<IEvent>);
-            await this.syncApi!.injectRoomEvents(this.room!, [], [event]);
+
+            // Only inject once we have update the txId
+            await this.updateTxId(event);
+
+            // The widget API does not tell us whether a state event came from `state_after` or not so we assume legacy behaviour for now.
+            if (this.syncApi instanceof SyncApi) {
+                // The code will want to be something like:
+                // ```
+                // if (!params.addToTimeline && !params.addToState) {
+                // // Passing undefined for `stateAfterEventList` makes `injectRoomEvents` run in "legacy mode"
+                // // -> state events part of the `timelineEventList` parameter will update the state.
+                //     this.injectRoomEvents(this.room!, [], undefined, [event]);
+                // } else {
+                //     this.injectRoomEvents(this.room!, undefined, params.addToState ? [event] : [], params.addToTimeline ? [event] : []);
+                // }
+                // ```
+
+                // Passing undefined for `stateAfterEventList` allows will make `injectRoomEvents` run in legacy mode
+                // -> state events in `timelineEventList` will update the state.
+                await this.syncApi.injectRoomEvents(this.room!, [], undefined, [event]);
+            } else {
+                // The code will want to be something like:
+                // ```
+                // if (!params.addToTimeline && !params.addToState) {
+                //     this.injectRoomEvents(this.room!, [], [event]);
+                // } else {
+                //     this.injectRoomEvents(this.room!, params.addToState ? [event] : [], params.addToTimeline ? [event] : []);
+                // }
+                // ```
+                await this.syncApi!.injectRoomEvents(this.room!, [], [event]); // Sliding Sync
+            }
             this.emit(ClientEvent.Event, event);
             this.setSyncState(SyncState.Syncing);
             logger.info(`Received event ${event.getId()} ${event.getType()} ${event.getStateKey()}`);

src/matrixrtc/MatrixRTCSession.ts

@@ -878,7 +878,7 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
             }
         }
 
-        if (this.manageMediaKeys && this.isJoined() && this.makeNewKeyTimeout === undefined) {
+        if (this.manageMediaKeys && this.isJoined()) {
             const oldMembershipIds = new Set(
                 oldMemberships.filter((m) => !this.isMyMembership(m)).map(getParticipantIdFromMembership),
             );
@@ -896,8 +896,12 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
             this.storeLastMembershipFingerprints();
 
             if (anyLeft) {
-                logger.debug(`Member(s) have left: queueing sender key rotation`);
-                this.makeNewKeyTimeout = setTimeout(this.onRotateKeyTimeout, this.makeKeyDelay);
+                if (this.makeNewKeyTimeout) {
+                    // existing rotation in progress, so let it complete
+                } else {
+                    logger.debug(`Member(s) have left: queueing sender key rotation`);
+                    this.makeNewKeyTimeout = setTimeout(this.onRotateKeyTimeout, this.makeKeyDelay);
+                }
             } else if (anyJoined) {
                 logger.debug(`New member(s) have joined: re-sending keys`);
                 this.requestSendCurrentKey();

src/matrixrtc/MatrixRTCSessionManager.ts

@@ -56,7 +56,7 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
 
     public start(): void {
         // We shouldn't need to null-check here, but matrix-client.spec.ts mocks getRooms
-        // returing nothing, and breaks tests if you change it to return an empty array :'(
+        // returning nothing, and breaks tests if you change it to return an empty array :'(
         for (const room of this.client.getRooms() ?? []) {
             const session = MatrixRTCSession.roomSessionForRoom(this.client, room);
             if (session.memberships.length > 0) {

src/models/event-timeline-set.ts

@@ -58,13 +58,13 @@ export interface IRoomTimelineData {
 }
 
 export interface IAddEventToTimelineOptions
-    extends Pick<IAddEventOptions, "toStartOfTimeline" | "roomState" | "timelineWasEmpty"> {
+    extends Pick<IAddEventOptions, "toStartOfTimeline" | "roomState" | "timelineWasEmpty" | "addToState"> {
     /** Whether the sync response came from cache */
     fromCache?: boolean;
 }
 
 export interface IAddLiveEventOptions
-    extends Pick<IAddEventToTimelineOptions, "fromCache" | "roomState" | "timelineWasEmpty"> {
+    extends Pick<IAddEventToTimelineOptions, "fromCache" | "roomState" | "timelineWasEmpty" | "addToState"> {
     /** Applies to events in the timeline only. If this is 'replace' then if a
      * duplicate is encountered, the event passed to this function will replace
      * the existing event in the timeline. If this is not specified, or is
@@ -391,6 +391,7 @@ export class EventTimelineSet extends TypedEventEmitter<EmittedEvents, EventTime
     public addEventsToTimeline(
         events: MatrixEvent[],
         toStartOfTimeline: boolean,
+        addToState: boolean,
         timeline: EventTimeline,
         paginationToken?: string | null,
     ): void {
@@ -495,6 +496,7 @@ export class EventTimelineSet extends TypedEventEmitter<EmittedEvents, EventTime
                 // we don't know about this event yet. Just add it to the timeline.
                 this.addEventToTimeline(event, timeline, {
                     toStartOfTimeline,
+                    addToState,
                 });
                 lastEventWasNew = true;
                 didUpdate = true;
@@ -592,7 +594,7 @@ export class EventTimelineSet extends TypedEventEmitter<EmittedEvents, EventTime
      */
     public addLiveEvent(
         event: MatrixEvent,
-        { duplicateStrategy, fromCache, roomState, timelineWasEmpty }: IAddLiveEventOptions = {},
+        { duplicateStrategy, fromCache, roomState, timelineWasEmpty, addToState }: IAddLiveEventOptions,
     ): void {
         if (this.filter) {
             const events = this.filter.filterRoomTimeline([event]);
@@ -630,6 +632,7 @@ export class EventTimelineSet extends TypedEventEmitter<EmittedEvents, EventTime
             fromCache,
             roomState,
             timelineWasEmpty,
+            addToState,
         });
     }
 
@@ -649,40 +652,8 @@ export class EventTimelineSet extends TypedEventEmitter<EmittedEvents, EventTime
     public addEventToTimeline(
         event: MatrixEvent,
         timeline: EventTimeline,
-        { toStartOfTimeline, fromCache, roomState, timelineWasEmpty }: IAddEventToTimelineOptions,
-    ): void;
-    /**
-     * @deprecated In favor of the overload with `IAddEventToTimelineOptions`
-     */
-    public addEventToTimeline(
-        event: MatrixEvent,
-        timeline: EventTimeline,
-        toStartOfTimeline: boolean,
-        fromCache?: boolean,
-        roomState?: RoomState,
-    ): void;
-    public addEventToTimeline(
-        event: MatrixEvent,
-        timeline: EventTimeline,
-        toStartOfTimelineOrOpts: boolean | IAddEventToTimelineOptions,
-        fromCache = false,
-        roomState?: RoomState,
+        { toStartOfTimeline, fromCache = false, roomState, timelineWasEmpty, addToState }: IAddEventToTimelineOptions,
     ): void {
-        let toStartOfTimeline = !!toStartOfTimelineOrOpts;
-        let timelineWasEmpty: boolean | undefined;
-        if (typeof toStartOfTimelineOrOpts === "object") {
-            ({ toStartOfTimeline, fromCache = false, roomState, timelineWasEmpty } = toStartOfTimelineOrOpts);
-        } else if (toStartOfTimelineOrOpts !== undefined) {
-            // Deprecation warning
-            // FIXME: Remove after 2023-06-01 (technical debt)
-            logger.warn(
-                "Overload deprecated: " +
-                    "`EventTimelineSet.addEventToTimeline(event, timeline, toStartOfTimeline, fromCache?, roomState?)` " +
-                    "is deprecated in favor of the overload with " +
-                    "`EventTimelineSet.addEventToTimeline(event, timeline, IAddEventToTimelineOptions)`",
-            );
-        }
-
         if (timeline.getTimelineSet() !== this) {
             throw new Error(`EventTimelineSet.addEventToTimeline: Timeline=${timeline.toString()} does not belong " +
                 "in timelineSet(threadId=${this.thread?.id})`);
@@ -713,6 +684,7 @@ export class EventTimelineSet extends TypedEventEmitter<EmittedEvents, EventTime
             toStartOfTimeline,
             roomState,
             timelineWasEmpty,
+            addToState,
         });
         this._eventIdToTimeline.set(eventId, timeline);
 
@@ -741,7 +713,12 @@ export class EventTimelineSet extends TypedEventEmitter<EmittedEvents, EventTime
      * @remarks
      * Fires {@link RoomEvent.Timeline}
      */
-    public insertEventIntoTimeline(event: MatrixEvent, timeline: EventTimeline, roomState: RoomState): void {
+    public insertEventIntoTimeline(
+        event: MatrixEvent,
+        timeline: EventTimeline,
+        roomState: RoomState,
+        addToState: boolean,
+    ): void {
         if (timeline.getTimelineSet() !== this) {
             throw new Error(`EventTimelineSet.insertEventIntoTimeline: Timeline=${timeline.toString()} does not belong " +
                 "in timelineSet(threadId=${this.thread?.id})`);
@@ -777,6 +754,7 @@ export class EventTimelineSet extends TypedEventEmitter<EmittedEvents, EventTime
                 fromCache: false,
                 timelineWasEmpty: false,
                 roomState,
+                addToState,
             });
             return;
         }
@@ -799,7 +777,7 @@ export class EventTimelineSet extends TypedEventEmitter<EmittedEvents, EventTime
         // If we got to the end of the loop, insertIndex points at the end of
         // the list.
 
-        timeline.insertEvent(event, insertIndex, roomState);
+        timeline.insertEvent(event, insertIndex, roomState, addToState);
         this._eventIdToTimeline.set(eventId, timeline);
 
         const data: IRoomTimelineData = {
@@ -832,6 +810,7 @@ export class EventTimelineSet extends TypedEventEmitter<EmittedEvents, EventTime
         } else if (!this.filter || this.filter.filterRoomTimeline([localEvent]).length) {
             this.addEventToTimeline(localEvent, this.liveTimeline, {
                 toStartOfTimeline: false,
+                addToState: false,
             });
         }
     }

src/models/event-timeline.ts

@@ -35,6 +35,11 @@ export interface IAddEventOptions extends Pick<IMarkerFoundOptions, "timelineWas
     toStartOfTimeline: boolean;
     /** The state events to reconcile metadata from */
     roomState?: RoomState;
+    /** Whether to add timeline events to the state as was done in legacy sync v2.
+     * If true then timeline events will be added to the state.
+     * In sync v2 with org.matrix.msc4222.use_state_after and simplified sliding sync,
+     * all state arrives explicitly and timeline events should not be added. */
+    addToState: boolean;
 }
 
 export enum Direction {
@@ -127,7 +132,7 @@ export class EventTimeline {
     public constructor(private readonly eventTimelineSet: EventTimelineSet) {
         this.roomId = eventTimelineSet.room?.roomId ?? null;
         if (this.roomId) {
-            this.startState = new RoomState(this.roomId, undefined, true);
+            this.startState = new RoomState(this.roomId);
             this.endState = new RoomState(this.roomId);
         }
 
@@ -362,7 +367,7 @@ export class EventTimeline {
      */
     public addEvent(
         event: MatrixEvent,
-        { toStartOfTimeline, roomState, timelineWasEmpty }: IAddEventOptions = { toStartOfTimeline: false },
+        { toStartOfTimeline, roomState, timelineWasEmpty, addToState }: IAddEventOptions,
     ): void {
         if (!roomState) {
             roomState = toStartOfTimeline ? this.startState : this.endState;
@@ -374,7 +379,7 @@ export class EventTimeline {
             EventTimeline.setEventMetadata(event, roomState!, toStartOfTimeline);
 
             // modify state but only on unfiltered timelineSets
-            if (event.isState() && timelineSet.room.getUnfilteredTimelineSet() === timelineSet) {
+            if (addToState && event.isState() && timelineSet.room.getUnfilteredTimelineSet() === timelineSet) {
                 roomState?.setStateEvents([event], { timelineWasEmpty });
                 // it is possible that the act of setting the state event means we
                 // can set more metadata (specifically sender/target props), so try
@@ -417,14 +422,14 @@ export class EventTimeline {
      *
      * @internal
      */
-    public insertEvent(event: MatrixEvent, insertIndex: number, roomState: RoomState): void {
+    public insertEvent(event: MatrixEvent, insertIndex: number, roomState: RoomState, addToState: boolean): void {
         const timelineSet = this.getTimelineSet();
 
         if (timelineSet.room) {
             EventTimeline.setEventMetadata(event, roomState, false);
 
             // modify state but only on unfiltered timelineSets
-            if (event.isState() && timelineSet.room.getUnfilteredTimelineSet() === timelineSet) {
+            if (addToState && event.isState() && timelineSet.room.getUnfilteredTimelineSet() === timelineSet) {
                 roomState.setStateEvents([event], {});
                 // it is possible that the act of setting the state event means we
                 // can set more metadata (specifically sender/target props), so try

src/models/event.ts

@@ -559,9 +559,9 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
             return {} as T;
         }
         if (this.clearEvent) {
-            return (this.clearEvent.content || {}) as T;
+            return (this.clearEvent.content ?? {}) as T;
         }
-        return (this.event.content || {}) as T;
+        return (this.event.content ?? {}) as T;
     }
 
     /**
@@ -575,7 +575,7 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
         if (this._localRedactionEvent) {
             return {} as T;
         } else if (this._replacingEvent) {
-            return this._replacingEvent.getContent()["m.new_content"] || {};
+            return this._replacingEvent.getContent()["m.new_content"] ?? {};
         } else {
             return this.getOriginalContent();
         }
@@ -1250,7 +1250,9 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
         const timeline = room.getLiveTimeline();
         // We use insertEventIntoTimeline to insert it in timestamp order,
         // because we don't know where it should go (until we have MSC4033).
-        timeline.getTimelineSet().insertEventIntoTimeline(this, timeline, timeline.getState(EventTimeline.FORWARDS)!);
+        timeline
+            .getTimelineSet()
+            .insertEventIntoTimeline(this, timeline, timeline.getState(EventTimeline.FORWARDS)!, false);
     }
 
     /**
@@ -1394,7 +1396,7 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
             this.emit(MatrixEventEvent.LocalEventIdReplaced, this);
         }
 
-        this.localTimestamp = Date.now() - this.getAge()!;
+        this.localTimestamp = Date.now() - (this.getAge() ?? 0);
     }
 
     /**
@@ -1631,7 +1633,7 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
      * @param otherEvent - The other event to check against.
      * @returns True if the events are the same, false otherwise.
      */
-    public isEquivalentTo(otherEvent: MatrixEvent): boolean {
+    public isEquivalentTo(otherEvent?: MatrixEvent): boolean {
         if (!otherEvent) return false;
         if (otherEvent === this) return true;
         const myProps = deepSortedObjectEntries(this.event);

src/models/relations.ts

@@ -20,6 +20,7 @@ import { RelationType } from "../@types/event.ts";
 import { TypedEventEmitter } from "./typed-event-emitter.ts";
 import { MatrixClient } from "../client.ts";
 import { Room } from "./room.ts";
+import { CryptoBackend } from "../common-crypto/CryptoBackend.ts";
 
 export enum RelationsEvent {
     Add = "Relations.add",
@@ -323,8 +324,9 @@ export class Relations extends TypedEventEmitter<RelationsEvent, EventHandlerMap
             return event;
         }, null);
 
-        if (lastReplacement?.shouldAttemptDecryption() && this.client.isCryptoEnabled()) {
-            await lastReplacement.attemptDecryption(this.client.crypto!);
+        if (lastReplacement?.shouldAttemptDecryption() && this.client.getCrypto()) {
+            // Dirty but we are expecting to pass the cryptoBackend which is not accessible here
+            await lastReplacement.attemptDecryption(this.client.getCrypto() as CryptoBackend);
         } else if (lastReplacement?.isBeingDecrypted()) {
             await lastReplacement.getDecryptionPromise();
         }

src/models/room-member.ts

@@ -408,17 +408,18 @@ const LTR_RTL_PATTERN = /[\u200E\u200F\u202A-\u202F]/;
 
 function shouldDisambiguate(selfUserId: string, displayName?: string, roomState?: RoomState): boolean {
     if (!displayName || displayName === selfUserId) return false;
+    if (!roomState) return false;
+
+    const strippedDisplayName = removeHiddenChars(displayName);
 
     // First check if the displayname is something we consider truthy
     // after stripping it of zero width characters and padding spaces
-    if (!removeHiddenChars(displayName)) return false;
-
-    if (!roomState) return false;
+    if (!strippedDisplayName) return false;
 
     // Next check if the name contains something that look like a mxid
     // If it does, it may be someone trying to impersonate someone else
     // Show full mxid in this case
-    if (MXID_PATTERN.test(displayName)) return true;
+    if (MXID_PATTERN.test(strippedDisplayName)) return true;
 
     // Also show mxid if the display name contains any LTR/RTL characters as these
     // make it very difficult for us to find similar *looking* display names

src/models/room-state.ts

@@ -194,22 +194,10 @@ export class RoomState extends TypedEventEmitter<EmittedEvents, EventHandlerMap>
      * As the timeline might get reset while they are loading, this state needs to be inherited
      * and shared when the room state is cloned for the new timeline.
      * This should only be passed from clone.
-     * @param isStartTimelineState - Optional. This state is marked as a start state.
-     * This is used to skip state insertions that are
-     * in the wrong order. The order is determined by the `replaces_state` id.
-     *
-     * Example:
-     * A current state events `replaces_state` value is `1`.
-     * Trying to insert a state event with `event_id` `1` in its place would fail if isStartTimelineState = false.
-     *
-     * A current state events `event_id` is `2`.
-     * Trying to insert a state event where its `replaces_state` value is `2` would fail if isStartTimelineState = true.
      */
-
     public constructor(
         public readonly roomId: string,
         private oobMemberFlags = { status: OobStatus.NotStarted },
-        public readonly isStartTimelineState = false,
     ) {
         super();
         this.updateModifiedTime();
@@ -420,7 +408,7 @@ export class RoomState extends TypedEventEmitter<EmittedEvents, EventHandlerMap>
      * Fires {@link RoomStateEvent.Events}
      * Fires {@link RoomStateEvent.Marker}
      */
-    public setStateEvents(stateEvents: MatrixEvent[], options?: IMarkerFoundOptions): void {
+    public setStateEvents(stateEvents: MatrixEvent[], markerFoundOptions?: IMarkerFoundOptions): void {
         this.updateModifiedTime();
 
         // update the core event dict
@@ -432,22 +420,6 @@ export class RoomState extends TypedEventEmitter<EmittedEvents, EventHandlerMap>
             }
 
             const lastStateEvent = this.getStateEventMatching(event);
-
-            // Safety measure to not update the room (and emit the update) with older state.
-            // The sync loop really should not send old events but it does very regularly.
-            // Logging on return in those two conditions results in a large amount of logging. (on startup and when running element)
-            const lastReplaceId = lastStateEvent?.event.unsigned?.replaces_state;
-            const lastId = lastStateEvent?.event.event_id;
-            const newReplaceId = event.event.unsigned?.replaces_state;
-            const newId = event.event.event_id;
-            if (this.isStartTimelineState) {
-                // Add an event to the start of the timeline. Its replace id should not be the same as the one of the current/last start state event.
-                if (newReplaceId && lastId && newReplaceId === lastId) return;
-            } else {
-                // Add an event to the end of the timeline. It should not be the same as the one replaced by the current/last end state event.
-                if (lastReplaceId && newId && lastReplaceId === newId) return;
-            }
-
             this.setStateEvent(event);
             if (event.getType() === EventType.RoomMember) {
                 this.updateDisplayNameCache(event.getStateKey()!, event.getContent().displayname ?? "");
@@ -504,7 +476,7 @@ export class RoomState extends TypedEventEmitter<EmittedEvents, EventHandlerMap>
                 // assume all our sentinels are now out-of-date
                 this.sentinels = {};
             } else if (UNSTABLE_MSC2716_MARKER.matches(event.getType())) {
-                this.emit(RoomStateEvent.Marker, event, options);
+                this.emit(RoomStateEvent.Marker, event, markerFoundOptions);
             }
         });
 

src/models/room.ts

@@ -545,7 +545,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      * @returns Signals when all events have been decrypted
      */
     public async decryptCriticalEvents(): Promise<void> {
-        if (!this.client.isCryptoEnabled()) return;
+        if (!this.client.getCrypto()) return;
 
         const readReceiptEventId = this.getEventReadUpTo(this.client.getUserId()!, true);
         const events = this.getLiveTimeline().getEvents();
@@ -567,7 +567,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      * @returns Signals when all events have been decrypted
      */
     public async decryptAllEvents(): Promise<void> {
-        if (!this.client.isCryptoEnabled()) return;
+        if (!this.client.getCrypto()) return;
 
         const decryptionPromises = this.getUnfilteredTimelineSet()
             .getLiveTimeline()
@@ -1739,10 +1739,11 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
     public addEventsToTimeline(
         events: MatrixEvent[],
         toStartOfTimeline: boolean,
+        addToState: boolean,
         timeline: EventTimeline,
         paginationToken?: string,
     ): void {
-        timeline.getTimelineSet().addEventsToTimeline(events, toStartOfTimeline, timeline, paginationToken);
+        timeline.getTimelineSet().addEventsToTimeline(events, toStartOfTimeline, addToState, timeline, paginationToken);
     }
 
     /**
@@ -1907,7 +1908,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
             // see https://github.com/vector-im/vector-web/issues/2109
 
             unfilteredLiveTimeline.getEvents().forEach(function (event) {
-                timelineSet.addLiveEvent(event);
+                timelineSet.addLiveEvent(event, { addToState: false }); // Filtered timeline sets should not track state
             });
 
             // find the earliest unfiltered timeline
@@ -1994,6 +1995,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
                 if (filterType !== ThreadFilterType.My || currentUserParticipated) {
                     timelineSet.getLiveTimeline().addEvent(thread.rootEvent!, {
                         toStartOfTimeline: false,
+                        addToState: false,
                     });
                 }
             });
@@ -2068,6 +2070,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
                 const opts = {
                     duplicateStrategy: DuplicateStrategy.Ignore,
                     fromCache: false,
+                    addToState: false,
                     roomState,
                 };
                 this.threadsTimelineSets[0]?.addLiveEvent(rootEvent, opts);
@@ -2190,6 +2193,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
                 duplicateStrategy: DuplicateStrategy.Replace,
                 fromCache: false,
                 roomState,
+                addToState: false,
             });
         }
     }
@@ -2381,9 +2385,13 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
                     duplicateStrategy: DuplicateStrategy.Replace,
                     fromCache: false,
                     roomState: this.currentState,
+                    addToState: false,
                 });
             } else {
-                timelineSet.addEventToTimeline(thread.rootEvent, timelineSet.getLiveTimeline(), { toStartOfTimeline });
+                timelineSet.addEventToTimeline(thread.rootEvent, timelineSet.getLiveTimeline(), {
+                    toStartOfTimeline,
+                    addToState: false,
+                });
             }
         }
     };
@@ -2540,7 +2548,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      * Fires {@link RoomEvent.Timeline}
      */
     private addLiveEvent(event: MatrixEvent, addLiveEventOptions: IAddLiveEventOptions): void {
-        const { duplicateStrategy, timelineWasEmpty, fromCache } = addLiveEventOptions;
+        const { duplicateStrategy, timelineWasEmpty, fromCache, addToState } = addLiveEventOptions;
 
         // add to our timeline sets
         for (const timelineSet of this.timelineSets) {
@@ -2548,6 +2556,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
                 duplicateStrategy,
                 fromCache,
                 timelineWasEmpty,
+                addToState,
             });
         }
 
@@ -2631,11 +2640,13 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
                     if (timelineSet.getFilter()!.filterRoomTimeline([event]).length) {
                         timelineSet.addEventToTimeline(event, timelineSet.getLiveTimeline(), {
                             toStartOfTimeline: false,
+                            addToState: false, // We don't support localEcho of state events yet
                         });
                     }
                 } else {
                     timelineSet.addEventToTimeline(event, timelineSet.getLiveTimeline(), {
                         toStartOfTimeline: false,
+                        addToState: false, // We don't support localEcho of state events yet
                     });
                 }
             }
@@ -2886,8 +2897,8 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      * @param addLiveEventOptions - addLiveEvent options
      * @throws If `duplicateStrategy` is not falsey, 'replace' or 'ignore'.
      */
-    public async addLiveEvents(events: MatrixEvent[], addLiveEventOptions?: IAddLiveEventOptions): Promise<void> {
-        const { duplicateStrategy, fromCache, timelineWasEmpty = false } = addLiveEventOptions ?? {};
+    public async addLiveEvents(events: MatrixEvent[], addLiveEventOptions: IAddLiveEventOptions): Promise<void> {
+        const { duplicateStrategy, fromCache, timelineWasEmpty = false, addToState } = addLiveEventOptions;
         if (duplicateStrategy && ["replace", "ignore"].indexOf(duplicateStrategy) === -1) {
             throw new Error("duplicateStrategy MUST be either 'replace' or 'ignore'");
         }
@@ -2902,6 +2913,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
             duplicateStrategy,
             fromCache,
             timelineWasEmpty,
+            addToState,
         };
 
         // List of extra events to check for being parents of any relations encountered

src/models/thread.ts

@@ -208,6 +208,7 @@ export class Thread extends ReadReceipt<ThreadEmittedEvents, ThreadEventHandlerM
 
     public static setServerSideSupport(status: FeatureSupport): void {
         Thread.hasServerSideSupport = status;
+        // XXX: This global latching behaviour is really unexpected and means that you can't undo when moving to a server without support
         if (status !== FeatureSupport.Stable) {
             FILTER_RELATED_BY_SENDERS.setPreferUnstable(true);
             FILTER_RELATED_BY_REL_TYPES.setPreferUnstable(true);
@@ -317,6 +318,7 @@ export class Thread extends ReadReceipt<ThreadEmittedEvents, ThreadEventHandlerM
                 toStartOfTimeline,
                 fromCache: false,
                 roomState: this.roomState,
+                addToState: false,
             });
         }
     }
@@ -343,7 +345,7 @@ export class Thread extends ReadReceipt<ThreadEmittedEvents, ThreadEventHandlerM
         if (this.findEventById(eventId)) {
             return;
         }
-        this.timelineSet.insertEventIntoTimeline(event, this.liveTimeline, this.roomState);
+        this.timelineSet.insertEventIntoTimeline(event, this.liveTimeline, this.roomState, false);
     }
 
     public addEvents(events: MatrixEvent[], toStartOfTimeline: boolean): void {
@@ -618,7 +620,7 @@ export class Thread extends ReadReceipt<ThreadEmittedEvents, ThreadEventHandlerM
                     // if the thread has regular events, this will just load the last reply.
                     // if the thread is newly created, this will load the root event.
                     if (this.replyCount === 0 && this.rootEvent) {
-                        this.timelineSet.addEventsToTimeline([this.rootEvent], true, this.liveTimeline, null);
+                        this.timelineSet.addEventsToTimeline([this.rootEvent], true, false, this.liveTimeline, null);
                         this.liveTimeline.setPaginationToken(null, Direction.Backward);
                     } else {
                         this.initalEventFetchProm = this.client.paginateEventTimeline(this.liveTimeline, {

src/rust-crypto/backup.ts

@@ -24,11 +24,12 @@ import {
     KeyBackupInfo,
     KeyBackupSession,
     Curve25519SessionData,
+    KeyBackupRestoreOpts,
+    KeyBackupRestoreResult,
     KeyBackupRoomSessions,
 } from "../crypto-api/keybackup.ts";
 import { logger } from "../logger.ts";
 import { ClientPrefix, IHttpOpts, MatrixError, MatrixHttpApi, Method } from "../http-api/index.ts";
-import { IMegolmSessionData } from "../crypto/index.ts";
 import { TypedEventEmitter } from "../models/typed-event-emitter.ts";
 import { encodeUri, logDuration } from "../utils.ts";
 import { OutgoingRequestProcessor } from "./OutgoingRequestProcessor.ts";
@@ -36,6 +37,7 @@ import { sleep } from "../utils.ts";
 import { BackupDecryptor } from "../common-crypto/CryptoBackend.ts";
 import { ImportRoomKeyProgressData, ImportRoomKeysOpts, CryptoEvent } from "../crypto-api/index.ts";
 import { AESEncryptedSecretStoragePayload } from "../@types/AESEncryptedSecretStoragePayload.ts";
+import { IMegolmSessionData } from "../@types/crypto.ts";
 
 /** Authentification of the backup info, depends on algorithm */
 type AuthData = KeyBackupInfo["auth_data"];
@@ -218,7 +220,7 @@ export class RustBackupManager extends TypedEventEmitter<RustBackupCryptoEvents,
     /**
      * Import a list of room keys previously exported by exportRoomKeysAsJson
      *
-     * @param keys - a JSON string encoding a list of session export objects,
+     * @param jsonKeys - 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
@@ -495,20 +497,19 @@ export class RustBackupManager extends TypedEventEmitter<RustBackupCryptoEvents,
      */
     private keysCountInBatch(batch: RustSdkCryptoJs.KeysBackupRequest): number {
         const parsedBody: KeyBackup = JSON.parse(batch.body);
-        let count = 0;
-        for (const { sessions } of Object.values(parsedBody.rooms)) {
-            count += Object.keys(sessions).length;
-        }
-        return count;
+        return countKeysInBackup(parsedBody);
     }
 
     /**
-     * Get information about the current key backup from the server
+     * Get information about a key backup from the server
+     * - If version is provided, get information about that backup version.
+     * - If no version is provided, get information about the latest backup.
      *
+     * @param version - The version of the backup to get information about.
      * @returns Information object from API or null if there is no active backup.
      */
-    private async requestKeyBackupVersion(): Promise<KeyBackupInfo | null> {
-        return await requestKeyBackupVersion(this.http);
+    public async requestKeyBackupVersion(version?: string): Promise<KeyBackupInfo | null> {
+        return await requestKeyBackupVersion(this.http, version);
     }
 
     /**
@@ -582,6 +583,11 @@ export class RustBackupManager extends TypedEventEmitter<RustBackupCryptoEvents,
         await this.http.authedRequest<void>(Method.Delete, path, undefined, undefined, {
             prefix: ClientPrefix.V3,
         });
+        // If the backup we are deleting is the active one, we need to disable the key backup and to have the local properties reset
+        if (this.activeBackupVersion === version) {
+            this.serverBackupInfo = null;
+            await this.disableKeyBackup();
+        }
     }
 
     /**
@@ -591,6 +597,148 @@ export class RustBackupManager extends TypedEventEmitter<RustBackupCryptoEvents,
     public createBackupDecryptor(decryptionKey: RustSdkCryptoJs.BackupDecryptionKey): BackupDecryptor {
         return new RustBackupDecryptor(decryptionKey);
     }
+
+    /**
+     * Restore a key backup.
+     *
+     * @param backupVersion - The version of the backup to restore.
+     * @param backupDecryptor - The backup decryptor to use to decrypt the keys.
+     * @param opts - Options for the restore.
+     * @returns The total number of keys and the total imported.
+     */
+    public async restoreKeyBackup(
+        backupVersion: string,
+        backupDecryptor: BackupDecryptor,
+        opts?: KeyBackupRestoreOpts,
+    ): Promise<KeyBackupRestoreResult> {
+        const keyBackup = await this.downloadKeyBackup(backupVersion);
+        opts?.progressCallback?.({
+            stage: "load_keys",
+        });
+
+        return this.importKeyBackup(keyBackup, backupVersion, backupDecryptor, opts);
+    }
+
+    /**
+     * Call `/room_keys/keys` to download the key backup (room keys) for the given backup version.
+     * https://spec.matrix.org/v1.12/client-server-api/#get_matrixclientv3room_keyskeys
+     *
+     * @param backupVersion
+     * @returns The key backup response.
+     */
+    private downloadKeyBackup(backupVersion: string): Promise<KeyBackup> {
+        return this.http.authedRequest<KeyBackup>(
+            Method.Get,
+            "/room_keys/keys",
+            { version: backupVersion },
+            undefined,
+            {
+                prefix: ClientPrefix.V3,
+            },
+        );
+    }
+
+    /**
+     * Import the room keys from a `/room_keys/keys` call.
+     * Calls `opts.progressCallback` with the progress of the import.
+     *
+     * @param keyBackup - The response from the server containing the keys to import.
+     * @param backupVersion - The version of the backup info.
+     * @param backupDecryptor - The backup decryptor to use to decrypt the keys.
+     * @param opts - Options for the import.
+     *
+     * @returns The total number of keys and the total imported.
+     *
+     * @private
+     */
+    private async importKeyBackup(
+        keyBackup: KeyBackup,
+        backupVersion: string,
+        backupDecryptor: BackupDecryptor,
+        opts?: KeyBackupRestoreOpts,
+    ): Promise<KeyBackupRestoreResult> {
+        // We have a full backup here, it can get quite big, so we need to decrypt and import it in chunks.
+
+        const CHUNK_SIZE = 200;
+        // Get the total count as a first pass
+        const totalKeyCount = countKeysInBackup(keyBackup);
+        let totalImported = 0;
+        let totalFailures = 0;
+
+        /**
+         * This method is called when we have enough chunks to decrypt.
+         * It will decrypt the chunks and try to import the room keys.
+         * @param roomChunks
+         */
+        const handleChunkCallback = async (roomChunks: Map<string, KeyBackupRoomSessions>): Promise<void> => {
+            const currentChunk: IMegolmSessionData[] = [];
+            for (const roomId of roomChunks.keys()) {
+                // Decrypt the sessions for the given room
+                const decryptedSessions = await backupDecryptor.decryptSessions(roomChunks.get(roomId)!);
+                // Add the decrypted sessions to the current chunk
+                decryptedSessions.forEach((session) => {
+                    // We set the room_id for each session
+                    session.room_id = roomId;
+                    currentChunk.push(session);
+                });
+            }
+
+            // We have a chunk of decrypted keys: import them
+            try {
+                await this.importBackedUpRoomKeys(currentChunk, backupVersion);
+                totalImported += currentChunk.length;
+            } catch (e) {
+                totalFailures += currentChunk.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);
+            }
+
+            opts?.progressCallback?.({
+                total: totalKeyCount,
+                successes: totalImported,
+                stage: "load_keys",
+                failures: totalFailures,
+            });
+        };
+
+        let groupChunkCount = 0;
+        let chunkGroupByRoom: Map<string, KeyBackupRoomSessions> = new Map();
+
+        // Iterate over the rooms and sessions to group them in chunks
+        // And we call the handleChunkCallback when we have enough chunks to decrypt
+        for (const [roomId, roomData] of Object.entries(keyBackup.rooms)) {
+            // If there are no sessions for the room, skip it
+            if (!roomData.sessions) continue;
+
+            // Initialize a new chunk group for the current room
+            chunkGroupByRoom.set(roomId, {});
+
+            for (const [sessionId, session] of Object.entries(roomData.sessions)) {
+                // We set previously the chunk group for the current room, so we can safely get it
+                const sessionsForRoom = chunkGroupByRoom.get(roomId)!;
+                sessionsForRoom[sessionId] = session;
+                groupChunkCount += 1;
+                // If we have enough chunks to decrypt, call the block callback
+                if (groupChunkCount >= CHUNK_SIZE) {
+                    // We have enough chunks to decrypt
+                    await handleChunkCallback(chunkGroupByRoom);
+                    // Reset the chunk group
+                    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);
+        }
+
+        return { total: totalKeyCount, imported: totalImported };
+    }
 }
 
 /**
@@ -657,11 +805,26 @@ export class RustBackupDecryptor implements BackupDecryptor {
     }
 }
 
+/**
+ * Fetch a key backup info from the server.
+ *
+ * If `version` is provided, calls `GET /room_keys/version/$version` and gets the backup info for that version.
+ * See https://spec.matrix.org/v1.12/client-server-api/#get_matrixclientv3room_keysversionversion.
+ *
+ * If not, calls `GET /room_keys/version` and gets the latest backup info.
+ * See https://spec.matrix.org/v1.12/client-server-api/#get_matrixclientv3room_keysversion
+ *
+ * @param http
+ * @param version - the specific version of the backup info to fetch
+ * @returns The key backup info or null if there is no backup.
+ */
 export async function requestKeyBackupVersion(
     http: MatrixHttpApi<IHttpOpts & { onlyData: true }>,
+    version?: string,
 ): Promise<KeyBackupInfo | null> {
     try {
-        return await http.authedRequest<KeyBackupInfo>(Method.Get, "/room_keys/version", undefined, undefined, {
+        const path = version ? encodeUri("/room_keys/version/$version", { $version: version }) : "/room_keys/version";
+        return await http.authedRequest<KeyBackupInfo>(Method.Get, path, undefined, undefined, {
             prefix: ClientPrefix.V3,
         });
     } catch (e) {
@@ -673,6 +836,34 @@ export async function requestKeyBackupVersion(
     }
 }
 
+/**
+ * Checks if the provided decryption key matches the public key of the key backup info.
+ *
+ * @param decryptionKey - The decryption key to check.
+ * @param keyBackupInfo - The key backup info to check against.
+ * @returns `true` if the decryption key matches the key backup info, `false` otherwise.
+ */
+export function decryptionKeyMatchesKeyBackupInfo(
+    decryptionKey: RustSdkCryptoJs.BackupDecryptionKey,
+    keyBackupInfo: KeyBackupInfo,
+): boolean {
+    const authData = <Curve25519AuthData>keyBackupInfo.auth_data;
+    return authData.public_key === decryptionKey.megolmV1PublicKey.publicKeyBase64;
+}
+
+/**
+ * Counts the total number of keys present in a key backup.
+ * @param keyBackup - The key backup to count the keys from.
+ * @returns The total number of keys in the backup.
+ */
+function countKeysInBackup(keyBackup: KeyBackup): number {
+    let count = 0;
+    for (const { sessions } of Object.values(keyBackup.rooms)) {
+        count += Object.keys(sessions).length;
+    }
+    return count;
+}
+
 export type RustBackupCryptoEvents =
     | CryptoEvent.KeyBackupStatus
     | CryptoEvent.KeyBackupSessionsRemaining

src/rust-crypto/libolm_migration.ts

@@ -21,7 +21,6 @@ import { CryptoStore, MigrationState, SecretStorePrivateKeys } from "../crypto/s
 import { IndexedDBCryptoStore } from "../crypto/store/indexeddb-crypto-store.ts";
 import { IHttpOpts, MatrixHttpApi } from "../http-api/index.ts";
 import { requestKeyBackupVersion } from "./backup.ts";
-import { IRoomEncryption } from "../crypto/RoomList.ts";
 import { CrossSigningKeyInfo, Curve25519AuthData } from "../crypto-api/index.ts";
 import { RustCrypto } from "./rust-crypto.ts";
 import { KeyBackupInfo } from "../crypto-api/keybackup.ts";
@@ -30,6 +29,12 @@ import { encodeBase64 } from "../base64.ts";
 import decryptAESSecretStorageItem from "../utils/decryptAESSecretStorageItem.ts";
 import { AESEncryptedSecretStoragePayload } from "../@types/AESEncryptedSecretStoragePayload.ts";
 
+interface LegacyRoomEncryption {
+    algorithm: string;
+    rotation_period_ms?: number;
+    rotation_period_msgs?: number;
+}
+
 /**
  * Determine if any data needs migrating from the legacy store, and do so.
  *
@@ -375,7 +380,7 @@ export async function migrateRoomSettingsFromLegacyCrypto({
         return;
     }
 
-    let rooms: Record<string, IRoomEncryption> = {};
+    let rooms: Record<string, LegacyRoomEncryption> = {};
 
     await legacyStore.doTxn("readwrite", [IndexedDBCryptoStore.STORE_ROOMS], (txn) => {
         legacyStore.getEndToEndRooms(txn, (result) => {

src/rust-crypto/rust-crypto.ts

@@ -46,7 +46,6 @@ import {
     CrossSigningStatus,
     CryptoApi,
     CryptoCallbacks,
-    Curve25519AuthData,
     DecryptionFailureCode,
     DeviceVerificationStatus,
     EventEncryptionInfo,
@@ -66,6 +65,8 @@ import {
     DeviceIsolationModeKind,
     CryptoEvent,
     CryptoEventHandlerMap,
+    KeyBackupRestoreOpts,
+    KeyBackupRestoreResult,
 } from "../crypto-api/index.ts";
 import { deviceKeysToDeviceMap, rustDeviceToJsDevice } from "./device-converter.ts";
 import { IDownloadKeyResult, IQueryKeysRequest } from "../client.ts";
@@ -76,16 +77,17 @@ import { secretStorageCanAccessSecrets, secretStorageContainsCrossSigningKeys }
 import { isVerificationEvent, RustVerificationRequest, verificationMethodIdentifierToMethod } from "./verification.ts";
 import { EventType, MsgType } from "../@types/event.ts";
 import { TypedEventEmitter } from "../models/typed-event-emitter.ts";
-import { RustBackupManager } from "./backup.ts";
+import { decryptionKeyMatchesKeyBackupInfo, RustBackupManager } from "./backup.ts";
 import { TypedReEmitter } from "../ReEmitter.ts";
 import { randomString } from "../randomstring.ts";
 import { ClientStoppedError } from "../errors.ts";
 import { ISignatures } from "../@types/signed.ts";
-import { encodeBase64 } from "../base64.ts";
+import { decodeBase64, encodeBase64 } from "../base64.ts";
 import { OutgoingRequestsManager } from "./OutgoingRequestsManager.ts";
 import { PerSessionKeyBackupDownloader } from "./PerSessionKeyBackupDownloader.ts";
 import { DehydratedDeviceManager } from "./DehydratedDeviceManager.ts";
 import { VerificationMethod } from "../types.ts";
+import { keyFromAuthData } from "../common-crypto/key-passphrase.ts";
 
 const ALL_VERIFICATION_METHODS = [
     VerificationMethod.Sas,
@@ -327,7 +329,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
     /**
      * Implementation of {@link CryptoBackend#getBackupDecryptor}.
      */
-    public async getBackupDecryptor(backupInfo: KeyBackupInfo, privKey: ArrayLike<number>): Promise<BackupDecryptor> {
+    public async getBackupDecryptor(backupInfo: KeyBackupInfo, privKey: Uint8Array): Promise<BackupDecryptor> {
         if (!(privKey instanceof Uint8Array)) {
             throw new Error(`getBackupDecryptor: expects Uint8Array`);
         }
@@ -337,9 +339,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
         }
 
         const backupDecryptionKey = RustSdkCryptoJs.BackupDecryptionKey.fromBase64(encodeBase64(privKey));
-
-        const authData = <Curve25519AuthData>backupInfo.auth_data;
-        if (authData.public_key != backupDecryptionKey.megolmV1PublicKey.publicKeyBase64) {
+        if (!decryptionKeyMatchesKeyBackupInfo(backupDecryptionKey, backupInfo)) {
             throw new Error(`getBackupDecryptor: key backup on server does not match the decryption key`);
         }
 
@@ -653,7 +653,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
      * Implementation of {@link CryptoApi#getUserVerificationStatus}.
      */
     public async getUserVerificationStatus(userId: string): Promise<UserVerificationStatus> {
-        const userIdentity: RustSdkCryptoJs.UserIdentity | RustSdkCryptoJs.OwnUserIdentity | undefined =
+        const userIdentity: RustSdkCryptoJs.OtherUserIdentity | RustSdkCryptoJs.OwnUserIdentity | undefined =
             await this.getOlmMachineOrThrow().getIdentity(new RustSdkCryptoJs.UserId(userId));
         if (userIdentity === undefined) {
             return new UserVerificationStatus(false, false, false);
@@ -662,7 +662,9 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
         const verified = userIdentity.isVerified();
         const wasVerified = userIdentity.wasPreviouslyVerified();
         const needsUserApproval =
-            userIdentity instanceof RustSdkCryptoJs.UserIdentity ? userIdentity.identityNeedsUserApproval() : false;
+            userIdentity instanceof RustSdkCryptoJs.OtherUserIdentity
+                ? userIdentity.identityNeedsUserApproval()
+                : false;
         userIdentity.free();
         return new UserVerificationStatus(verified, wasVerified, false, needsUserApproval);
     }
@@ -671,7 +673,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
      * Implementation of {@link CryptoApi#pinCurrentUserIdentity}.
      */
     public async pinCurrentUserIdentity(userId: string): Promise<void> {
-        const userIdentity: RustSdkCryptoJs.UserIdentity | RustSdkCryptoJs.OwnUserIdentity | undefined =
+        const userIdentity: RustSdkCryptoJs.OtherUserIdentity | RustSdkCryptoJs.OwnUserIdentity | undefined =
             await this.getOlmMachineOrThrow().getIdentity(new RustSdkCryptoJs.UserId(userId));
 
         if (userIdentity === undefined) {
@@ -1020,7 +1022,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
      * Implementation of {@link CryptoApi#requestVerificationDM}
      */
     public async requestVerificationDM(userId: string, roomId: string): Promise<VerificationRequest> {
-        const userIdentity: RustSdkCryptoJs.UserIdentity | undefined = await this.olmMachine.getIdentity(
+        const userIdentity: RustSdkCryptoJs.OtherUserIdentity | undefined = await this.olmMachine.getIdentity(
             new RustSdkCryptoJs.UserId(userId),
         );
 
@@ -1178,7 +1180,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
     public async getSessionBackupPrivateKey(): Promise<Uint8Array | null> {
         const backupKeys: RustSdkCryptoJs.BackupKeys = await this.olmMachine.getBackupKeys();
         if (!backupKeys.decryptionKey) return null;
-        return Buffer.from(backupKeys.decryptionKey.toBase64(), "base64");
+        return decodeBase64(backupKeys.decryptionKey.toBase64());
     }
 
     /**
@@ -1202,6 +1204,28 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
         );
     }
 
+    /**
+     * Implementation of {@link CryptoApi#loadSessionBackupPrivateKeyFromSecretStorage}.
+     */
+    public async loadSessionBackupPrivateKeyFromSecretStorage(): Promise<void> {
+        const backupKey = await this.secretStorage.get("m.megolm_backup.v1");
+        if (!backupKey) {
+            throw new Error("loadSessionBackupPrivateKeyFromSecretStorage: missing decryption key in secret storage");
+        }
+
+        const keyBackupInfo = await this.backupManager.getServerBackupInfo();
+        if (!keyBackupInfo || !keyBackupInfo.version) {
+            throw new Error("loadSessionBackupPrivateKeyFromSecretStorage: unable to get backup version");
+        }
+
+        const backupDecryptionKey = RustSdkCryptoJs.BackupDecryptionKey.fromBase64(backupKey);
+        if (!decryptionKeyMatchesKeyBackupInfo(backupDecryptionKey, keyBackupInfo)) {
+            throw new Error("loadSessionBackupPrivateKeyFromSecretStorage: decryption key does not match backup info");
+        }
+
+        await this.backupManager.saveBackupDecryptionKey(backupDecryptionKey, keyBackupInfo.version);
+    }
+
     /**
      * Get the current status of key backup.
      *
@@ -1211,6 +1235,13 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
         return await this.backupManager.getActiveBackupVersion();
     }
 
+    /**
+     * Implementation of {@link CryptoApi#getKeyBackupInfo}.
+     */
+    public async getKeyBackupInfo(): Promise<KeyBackupInfo | null> {
+        return (await this.backupManager.getServerBackupInfo()) || null;
+    }
+
     /**
      * Determine if a key backup can be trusted.
      *
@@ -1280,6 +1311,53 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
         obj.signatures = Object.fromEntries(sigs.entries());
     }
 
+    /**
+     * Implementation of {@link CryptoApi#restoreKeyBackupWithPassphrase}.
+     */
+    public async restoreKeyBackupWithPassphrase(
+        passphrase: string,
+        opts?: KeyBackupRestoreOpts,
+    ): Promise<KeyBackupRestoreResult> {
+        const backupInfo = await this.backupManager.getServerBackupInfo();
+        if (!backupInfo?.version) {
+            throw new Error("No backup info available");
+        }
+
+        const privateKey = await keyFromAuthData(backupInfo.auth_data, passphrase);
+
+        // Cache the key
+        await this.storeSessionBackupPrivateKey(privateKey, backupInfo.version);
+        return this.restoreKeyBackup(opts);
+    }
+
+    /**
+     * Implementation of {@link CryptoApi#restoreKeyBackup}.
+     */
+    public async restoreKeyBackup(opts?: KeyBackupRestoreOpts): Promise<KeyBackupRestoreResult> {
+        // Get the decryption key from the crypto store
+        const backupKeys: RustSdkCryptoJs.BackupKeys = await this.olmMachine.getBackupKeys();
+        const { decryptionKey, backupVersion } = backupKeys;
+        if (!decryptionKey || !backupVersion) throw new Error("No decryption key found in crypto store");
+
+        const decodedDecryptionKey = decodeBase64(decryptionKey.toBase64());
+
+        const backupInfo = await this.backupManager.requestKeyBackupVersion(backupVersion);
+        if (!backupInfo) throw new Error(`Backup version to restore ${backupVersion} not found on server`);
+
+        const backupDecryptor = await this.getBackupDecryptor(backupInfo, decodedDecryptionKey);
+
+        try {
+            opts?.progressCallback?.({
+                stage: "fetch",
+            });
+
+            return await this.backupManager.restoreKeyBackup(backupVersion, backupDecryptor, opts);
+        } finally {
+            // Free to avoid to keep in memory the decryption key stored in it. To avoid to exposing it to an attacker.
+            backupDecryptor.free();
+        }
+    }
+
     /**
      * Implementation of {@link CryptoApi#isDehydrationSupported}.
      */
@@ -1959,7 +2037,7 @@ class EventDecryptor {
                     errorDetails,
                 );
 
-            case RustSdkCryptoJs.DecryptionErrorCode.SenderIdentityPreviouslyVerified:
+            case RustSdkCryptoJs.DecryptionErrorCode.SenderIdentityVerificationViolation:
                 // We're refusing to decrypt due to not trusting the sender,
                 // rather than failing to decrypt due to lack of keys, so we
                 // don't need to keep it on the pending list.
@@ -2104,22 +2182,29 @@ function rustEncryptionInfoToJsEncryptionInfo(
     }
 
     let shieldReason: EventShieldReason | null;
-    if (shieldState.message === undefined) {
-        shieldReason = null;
-    } else if (shieldState.message === "Encrypted by an unverified user.") {
-        // this case isn't actually used with lax shield semantics.
-        shieldReason = EventShieldReason.UNVERIFIED_IDENTITY;
-    } else if (shieldState.message === "Encrypted by a device not verified by its owner.") {
-        shieldReason = EventShieldReason.UNSIGNED_DEVICE;
-    } else if (
-        shieldState.message === "The authenticity of this encrypted message can't be guaranteed on this device."
-    ) {
-        shieldReason = EventShieldReason.AUTHENTICITY_NOT_GUARANTEED;
-    } else if (shieldState.message === "Encrypted by an unknown or deleted device.") {
-        shieldReason = EventShieldReason.UNKNOWN_DEVICE;
-    } else {
-        logger.warn(`Unknown shield state message '${shieldState.message}'`);
-        shieldReason = EventShieldReason.UNKNOWN;
+    switch (shieldState.code) {
+        case undefined:
+        case null:
+            shieldReason = null;
+            break;
+        case RustSdkCryptoJs.ShieldStateCode.AuthenticityNotGuaranteed:
+            shieldReason = EventShieldReason.AUTHENTICITY_NOT_GUARANTEED;
+            break;
+        case RustSdkCryptoJs.ShieldStateCode.UnknownDevice:
+            shieldReason = EventShieldReason.UNKNOWN_DEVICE;
+            break;
+        case RustSdkCryptoJs.ShieldStateCode.UnsignedDevice:
+            shieldReason = EventShieldReason.UNSIGNED_DEVICE;
+            break;
+        case RustSdkCryptoJs.ShieldStateCode.UnverifiedIdentity:
+            shieldReason = EventShieldReason.UNVERIFIED_IDENTITY;
+            break;
+        case RustSdkCryptoJs.ShieldStateCode.SentInClear:
+            shieldReason = EventShieldReason.SENT_IN_CLEAR;
+            break;
+        case RustSdkCryptoJs.ShieldStateCode.VerificationViolation:
+            shieldReason = EventShieldReason.VERIFICATION_VIOLATION;
+            break;
     }
 
     return { shieldColour, shieldReason };

src/rust-crypto/verification.ts

@@ -381,8 +381,8 @@ export class RustVerificationRequest
      * @param qrCodeData - the decoded QR code.
      * @returns A verifier; call `.verify()` on it to wait for the other side to complete the verification flow.
      */
-    public async scanQRCode(uint8Array: Uint8Array): Promise<Verifier> {
-        const scan = RustSdkCryptoJs.QrCodeScan.fromBytes(new Uint8ClampedArray(uint8Array));
+    public async scanQRCode(uint8Array: Uint8ClampedArray): Promise<Verifier> {
+        const scan = RustSdkCryptoJs.QrCodeScan.fromBytes(uint8Array);
         const verifier: RustSdkCryptoJs.Qr = await this.inner.scanQrCode(scan);
 
         // this should have triggered the onChange callback, and we should now have a verifier
@@ -416,7 +416,7 @@ export class RustVerificationRequest
     /**
      * Stub implementation of {@link Crypto.VerificationRequest#getQRCodeBytes}.
      */
-    public getQRCodeBytes(): Buffer | undefined {
+    public getQRCodeBytes(): Uint8ClampedArray | undefined {
         throw new Error("getQRCodeBytes() unsupported in Rust Crypto; use generateQRCode() instead.");
     }
 
@@ -425,7 +425,7 @@ export class RustVerificationRequest
      *
      * Implementation of {@link Crypto.VerificationRequest#generateQRCode}.
      */
-    public async generateQRCode(): Promise<Buffer | undefined> {
+    public async generateQRCode(): Promise<Uint8ClampedArray | undefined> {
         // make sure that we have a list of the other user's devices (workaround https://github.com/matrix-org/matrix-rust-sdk/issues/2896)
         if (!(await this.getOtherDevice())) {
             throw new Error("generateQRCode(): other device is unknown");
@@ -435,7 +435,7 @@ export class RustVerificationRequest
         // If we are unable to generate a QRCode, we return undefined
         if (!innerVerifier) return;
 
-        return Buffer.from(innerVerifier.toBytes());
+        return innerVerifier.toBytes();
     }
 
     /**