v34.4.0

[Backport staging] Rename slowReporter to reflect that it is CommonJS

.github/workflows/release-gitflow.yml

@@ -34,6 +34,7 @@ jobs:
             - uses: actions/setup-node@v4
               with:
                   cache: "yarn"
+                  node-version-file: package.json
 
             - name: Install Deps
               run: "yarn install --frozen-lockfile"

.github/workflows/release-make.yml

@@ -316,6 +316,11 @@ jobs:
                   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 }}

.github/workflows/tests.yml

@@ -18,7 +18,7 @@ jobs:
         strategy:
             matrix:
                 specs: [integ, unit]
-                node: ["lts/*", 21, 22]
+                node: ["lts/*", 22]
         steps:
             - name: Checkout code
               uses: actions/checkout@v4
@@ -63,6 +63,16 @@ jobs:
                       coverage
                       !coverage/lcov-report
 
+    # Dummy completion job to simplify branch protections
+    jest-complete:
+        name: Jest tests
+        needs: jest
+        if: always()
+        runs-on: ubuntu-latest
+        steps:
+            - if: needs.jest.result != 'skipped' && needs.jest.result != 'success'
+              run: exit 1
+
     matrix-react-sdk:
         name: Downstream test matrix-react-sdk
         if: github.event_name == 'merge_group'

CHANGELOG.md

@@ -1,3 +1,62 @@
+Changes in [34.4.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v34.4.0) (2024-08-27)
+==================================================================================================
+## ✨ Features
+
+* Use non-legacy calls if any are found ([#4337](https://github.com/matrix-org/matrix-js-sdk/pull/4337)). Contributed by @AndrewFerr.
+
+## 🐛 Bug Fixes
+
+* Retry event decryption failures on first failure ([#4346](https://github.com/matrix-org/matrix-js-sdk/pull/4346)). Contributed by @hughns.
+* Ensure "type" = "module" ES declaration in pre-release.sh ([#4350](https://github.com/matrix-org/matrix-js-sdk/pull/4350)). Contributed by @BLCK-B.
+* Handle MatrixRTC encryption keys arriving out of order ([#4345](https://github.com/matrix-org/matrix-js-sdk/pull/4345)). Contributed by @hughns.
+* Resend MatrixRTC encryption keys if a membership has changed ([#4343](https://github.com/matrix-org/matrix-js-sdk/pull/4343)). Contributed by @hughns.
+
+
+Changes in [34.3.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v34.3.1) (2024-08-20)
+==================================================================================================
+# Security
+- Fixes for [CVE-2024-42369](https://nvd.nist.gov/vuln/detail/CVE-2024-42369) / [GHSA-vhr5-g3pm-49fm](https://github.com/matrix-org/matrix-js-sdk/security/advisories/GHSA-vhr5-g3pm-49fm).
+
+Changes in [34.3.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v34.3.0) (2024-08-13)
+==================================================================================================
+## ✨ Features
+
+* Bump matrix-widget-api ([#4336](https://github.com/matrix-org/matrix-js-sdk/pull/4336)). Contributed by @AndrewFerr.
+* Also check for MSC3757 for session state keys ([#4334](https://github.com/matrix-org/matrix-js-sdk/pull/4334)). Contributed by @AndrewFerr.
+* Support Futures via widgets ([#4311](https://github.com/matrix-org/matrix-js-sdk/pull/4311)). Contributed by @AndrewFerr.
+* Support MSC4140: Delayed events (Futures) ([#4294](https://github.com/matrix-org/matrix-js-sdk/pull/4294)). Contributed by @AndrewFerr.
+* Handle late-arriving `m.room_key.withheld` messages ([#4310](https://github.com/matrix-org/matrix-js-sdk/pull/4310)). Contributed by @richvdh.
+* Be specific about what is considered a MSC4143 call member event. ([#4328](https://github.com/matrix-org/matrix-js-sdk/pull/4328)). Contributed by @toger5.
+* Add index.ts for matrixrtc module ([#4314](https://github.com/matrix-org/matrix-js-sdk/pull/4314)). Contributed by @toger5.
+
+## 🐛 Bug Fixes
+
+* Fix hashed ID server lookups with no Olm ([#4333](https://github.com/matrix-org/matrix-js-sdk/pull/4333)). Contributed by @dbkr.
+
+
+Changes in [34.2.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v34.2.0) (2024-07-30)
+==================================================================================================
+## 🐛 Bug Fixes
+
+* Element-R: detect "withheld key" UTD errors, and mark them as such ([#4302](https://github.com/matrix-org/matrix-js-sdk/pull/4302)). Contributed by @richvdh.
+
+
+Changes in [34.1.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v34.1.0) (2024-07-16)
+==================================================================================================
+## ✨ Features
+
+* Add ability to choose how many timeline events to sync when peeking ([#4300](https://github.com/matrix-org/matrix-js-sdk/pull/4300)). Contributed by @jgarplind.
+* Remove redundant hack for using the old pickle key in rust crypto ([#4282](https://github.com/matrix-org/matrix-js-sdk/pull/4282)). Contributed by @richvdh.
+* Add fetching the well known in embedded mode. ([#4259](https://github.com/matrix-org/matrix-js-sdk/pull/4259)). Contributed by @toger5.
+
+## 🐛 Bug Fixes
+
+* Fix room state being updated with old (now overwritten) state and emitting for those updates. ([#4242](https://github.com/matrix-org/matrix-js-sdk/pull/4242)). Contributed by @toger5.
+* Fix incorrect "Olm is not available" errors ([#4301](https://github.com/matrix-org/matrix-js-sdk/pull/4301)). Contributed by @richvdh.
+* Fix build for example script ([#4286](https://github.com/matrix-org/matrix-js-sdk/pull/4286)). Contributed by @richvdh.
+* Declare matrix-js-sdk as an ES module ([#4285](https://github.com/matrix-org/matrix-js-sdk/pull/4285)). Contributed by @richvdh.
+
+
 Changes in [34.0.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v34.0.0) (2024-07-08)
 ==================================================================================================
 ## 🚨 BREAKING CHANGES

README.md

@@ -39,7 +39,7 @@ 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) for a more complex example.
+[the Node.js terminal app](examples/node/README.md) for a more complex example.
 
 To start the client:
 

jest.config.ts

@@ -39,7 +39,7 @@ if (env["GITHUB_ACTIONS"] !== undefined) {
 
     // if we're running against the develop branch, also enable the slow test reporter
     if (env["GITHUB_REF"] == "refs/heads/develop") {
-        reporters.push("<rootDir>/spec/slowReporter.js");
+        reporters.push("<rootDir>/spec/slowReporter.cjs");
     }
     config.reporters = reporters;
 }

package.json

@@ -1,6 +1,6 @@
 {
     "name": "matrix-js-sdk",
-    "version": "34.1.0-rc.0",
+    "version": "34.4.0",
     "description": "Matrix Client-Server SDK for Javascript",
     "engines": {
         "node": ">=20.0.0"
@@ -31,6 +31,7 @@
     "keywords": [
         "matrix-org"
     ],
+    "type": "module",
     "main": "./lib/index.js",
     "browser": "./lib/browser-index.js",
     "matrix_src_main": "./src/index.ts",
@@ -53,14 +54,15 @@
     ],
     "dependencies": {
         "@babel/runtime": "^7.12.5",
-        "@matrix-org/matrix-sdk-crypto-wasm": "^6.0.0",
+        "@matrix-org/matrix-sdk-crypto-wasm": "^7.0.0",
+        "@matrix-org/olm": "3.2.15",
         "another-json": "^0.2.0",
         "bs58": "^6.0.0",
         "content-type": "^1.0.4",
         "jwt-decode": "^4.0.0",
         "loglevel": "^1.7.1",
         "matrix-events-sdk": "0.0.1",
-        "matrix-widget-api": "^1.6.0",
+        "matrix-widget-api": "^1.8.2",
         "oidc-client-ts": "^3.0.1",
         "p-retry": "4",
         "sdp-transform": "^2.14.1",
@@ -82,7 +84,6 @@
         "@babel/preset-env": "^7.12.11",
         "@babel/preset-typescript": "^7.12.7",
         "@casualbot/jest-sonar-reporter": "2.2.7",
-        "@matrix-org/olm": "3.2.15",
         "@peculiar/webcrypto": "^1.4.5",
         "@types/bs58": "^4.0.1",
         "@types/content-type": "^1.1.5",
@@ -106,7 +107,7 @@
         "eslint-plugin-tsdoc": "^0.3.0",
         "eslint-plugin-unicorn": "^54.0.0",
         "fake-indexeddb": "^5.0.2",
-        "fetch-mock": "10.0.7",
+        "fetch-mock": "10.1.0",
         "fetch-mock-jest": "^1.5.1",
         "husky": "^9.0.0",
         "jest": "^29.0.0",
@@ -117,8 +118,8 @@
         "lint-staged": "^15.0.2",
         "matrix-mock-request": "^2.5.0",
         "node-fetch": "^2.7.0",
-        "prettier": "3.3.2",
-        "rimraf": "^5.0.0",
+        "prettier": "3.3.3",
+        "rimraf": "^6.0.0",
         "ts-node": "^10.9.2",
         "typedoc": "^0.26.0",
         "typedoc-plugin-coverage": "^3.0.0",

scripts/switch_package_to_release.cjs

@@ -0,0 +1,18 @@
+#!/usr/bin/env node
+
+const fsProm = require("fs/promises");
+
+const PKGJSON = "package.json";
+
+async function main() {
+    const pkgJson = JSON.parse(await fsProm.readFile(PKGJSON, "utf8"));
+    for (const field of ["main", "typings"]) {
+        if (pkgJson["matrix_lib_" + field] !== undefined) {
+            pkgJson[field] = pkgJson["matrix_lib_" + field];
+        }
+    }
+
+    await fsProm.writeFile(PKGJSON, JSON.stringify(pkgJson, null, 2));
+}
+
+main();

scripts/switch_package_to_release.js

@@ -1,22 +0,0 @@
-#!/usr/bin/env node
-
-const fsProm = require("fs/promises");
-
-const PKGJSON = "package.json";
-
-async function main() {
-    const pkgJson = JSON.parse(await fsProm.readFile(PKGJSON, "utf8"));
-    for (const field of ["main", "typings"]) {
-        if (pkgJson["matrix_lib_" + field] !== undefined) {
-            pkgJson[field] = pkgJson["matrix_lib_" + field];
-        }
-    }
-
-    // matrix-js-sdk is built into ECMAScript modules. Make sure we declare it as such.
-    // See https://nodejs.org/api/packages.html#type.
-    pkgJson["type"] = "module";
-
-    await fsProm.writeFile(PKGJSON, JSON.stringify(pkgJson, null, 2));
-}
-
-main();

scripts/switch_package_to_release.js

@@ -0,0 +1 @@
+switch_package_to_release.cjs

spec/integ/crypto/crypto.spec.ts

@@ -2333,8 +2333,84 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("crypto (%s)", (backend: string,
     });
 
     describe("m.room_key.withheld handling", () => {
-        // TODO: there are a bunch more tests for this sort of thing in spec/unit/crypto/algorithms/megolm.spec.ts.
-        //   They should be converted to integ tests and moved.
+        describe.each([
+            ["m.blacklisted", "The sender has blocked you.", DecryptionFailureCode.MEGOLM_KEY_WITHHELD],
+            [
+                "m.unverified",
+                "The sender has disabled encrypting to unverified devices.",
+                DecryptionFailureCode.MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE,
+            ],
+        ])(
+            "Decryption fails with withheld error if a withheld notice with code '%s' is received",
+            (withheldCode, expectedMessage, expectedErrorCode) => {
+                it.each(["before", "after"])("%s the event", async (when) => {
+                    expectAliceKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
+                    await startClientAndAwaitFirstSync();
+
+                    // A promise which resolves, with the MatrixEvent which wraps the event, once the decryption fails.
+                    let awaitDecryption = emitPromise(aliceClient, MatrixEventEvent.Decrypted);
+
+                    // Send Alice an encrypted room event which looks like it was encrypted with a megolm session
+                    async function sendEncryptedEvent() {
+                        const event = {
+                            ...testData.ENCRYPTED_EVENT,
+                            origin_server_ts: Date.now(),
+                        };
+                        const syncResponse = {
+                            next_batch: 1,
+                            rooms: { join: { [ROOM_ID]: { timeline: { events: [event] } } } },
+                        };
+
+                        syncResponder.sendOrQueueSyncResponse(syncResponse);
+                        await syncPromise(aliceClient);
+                    }
+
+                    // Send Alice a withheld notice
+                    async function sendWithheldMessage() {
+                        const withheldMessage = {
+                            type: "m.room_key.withheld",
+                            sender: "@bob:example.com",
+                            content: {
+                                algorithm: "m.megolm.v1.aes-sha2",
+                                room_id: ROOM_ID,
+                                sender_key: testData.ENCRYPTED_EVENT.content!.sender_key,
+                                session_id: testData.ENCRYPTED_EVENT.content!.session_id,
+                                code: withheldCode,
+                                reason: "zzz",
+                            },
+                        };
+
+                        syncResponder.sendOrQueueSyncResponse({
+                            next_batch: 1,
+                            to_device: { events: [withheldMessage] },
+                        });
+                        await syncPromise(aliceClient);
+                    }
+
+                    if (when === "before") {
+                        await sendWithheldMessage();
+                        await sendEncryptedEvent();
+                    } else {
+                        await sendEncryptedEvent();
+                        // Make sure that the first attempt to decrypt has happened before the withheld arrives
+                        await awaitDecryption;
+                        awaitDecryption = emitPromise(aliceClient, MatrixEventEvent.Decrypted);
+                        await sendWithheldMessage();
+                    }
+
+                    const ev = await awaitDecryption;
+                    expect(ev.getContent()).toEqual({
+                        body: `** Unable to decrypt: DecryptionError: ${expectedMessage} **`,
+                        msgtype: "m.bad.encrypted",
+                    });
+
+                    expect(ev.decryptionFailureReason).toEqual(expectedErrorCode);
+
+                    // `isEncryptedDisabledForUnverifiedDevices` should be true for `m.unverified` and false for other errors.
+                    expect(ev.isEncryptedDisabledForUnverifiedDevices).toEqual(withheldCode === "m.unverified");
+                });
+            },
+        );
 
         oldBackendOnly("does not block decryption on an 'm.unavailable' report", async function () {
             // there may be a key downloads for alice

spec/integ/rendezvous/MSC4108SignInWithQR.spec.ts

@@ -268,7 +268,8 @@ describe("MSC4108SignInWithQR", () => {
         it("should abort if device doesn't come up by timeout", async () => {
             jest.spyOn(global, "setTimeout").mockImplementation((fn) => {
                 (<Function>fn)();
-                return -1;
+                // TODO: mock timers properly
+                return -1 as any;
             });
             jest.spyOn(Date, "now").mockImplementation(() => {
                 return 12345678 + mocked(setTimeout).mock.calls.length * 1000;
@@ -320,7 +321,8 @@ describe("MSC4108SignInWithQR", () => {
         it("should not send secrets if user cancels", async () => {
             jest.spyOn(global, "setTimeout").mockImplementation((fn) => {
                 (<Function>fn)();
-                return -1;
+                // TODO: mock timers properly
+                return -1 as any;
             });
 
             await Promise.all([ourLogin.negotiateProtocols(), opponentLogin.negotiateProtocols()]);

spec/unit/digest.spec.ts

@@ -0,0 +1,40 @@
+/*
+Copyright 2024 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { encodeUnpaddedBase64Url } from "../../src";
+import { sha256 } from "../../src/digest";
+
+describe("sha256", () => {
+    it("should hash a string", async () => {
+        const hash = await sha256("test");
+        expect(encodeUnpaddedBase64Url(hash)).toBe("n4bQgYhMfWWaL-qgxVrQFaO_TxsrC4Is0V1sFbDwCgg");
+    });
+
+    it("should hash a string with emoji", async () => {
+        const hash = await sha256("test 🍱");
+        expect(encodeUnpaddedBase64Url(hash)).toBe("X2aDNrrwfq3nCTOl90R9qg9ynxhHnSzsMqtrdYX-SGw");
+    });
+
+    it("throws if webcrypto is not available", async () => {
+        const oldCrypto = global.crypto;
+        try {
+            global.crypto = {} as any;
+            await expect(sha256("test")).rejects.toThrow();
+        } finally {
+            global.crypto = oldCrypto;
+        }
+    });
+});

spec/unit/embedded.spec.ts

@@ -32,7 +32,7 @@ import {
     IOpenIDCredentials,
 } from "matrix-widget-api";
 
-import { createRoomWidgetClient, MsgType } from "../../src/matrix";
+import { createRoomWidgetClient, MsgType, UpdateDelayedEventAction } from "../../src/matrix";
 import { MatrixClient, ClientEvent, ITurnServer as IClientTurnServer } from "../../src/client";
 import { SyncState } from "../../src/sync";
 import { ICapabilities } from "../../src/embedded";
@@ -59,8 +59,26 @@ class MockWidgetApi extends EventEmitter {
     public requestCapabilityToReceiveState = jest.fn();
     public requestCapabilityToSendToDevice = jest.fn();
     public requestCapabilityToReceiveToDevice = jest.fn();
-    public sendRoomEvent = jest.fn(() => ({ event_id: `$${Math.random()}` }));
-    public sendStateEvent = jest.fn();
+    public sendRoomEvent = jest.fn(
+        (eventType: string, content: unknown, roomId?: string, delay?: number, parentDelayId?: string) =>
+            delay === undefined && parentDelayId === undefined
+                ? { event_id: `$${Math.random()}` }
+                : { delay_id: `id-${Math.random()}` },
+    );
+    public sendStateEvent = jest.fn(
+        (
+            eventType: string,
+            stateKey: string,
+            content: unknown,
+            roomId?: string,
+            delay?: number,
+            parentDelayId?: string,
+        ) =>
+            delay === undefined && parentDelayId === undefined
+                ? { event_id: `$${Math.random()}` }
+                : { delay_id: `id-${Math.random()}` },
+    );
+    public updateDelayedEvent = jest.fn();
     public sendToDevice = jest.fn();
     public requestOpenIDConnectToken = jest.fn(() => {
         return testOIDCToken;
@@ -125,6 +143,17 @@ describe("RoomWidgetClient", () => {
             );
         });
 
+        it("send handles wrong field in response", async () => {
+            await makeClient({ sendEvent: ["org.matrix.rageshake_request"] });
+            widgetApi.sendRoomEvent.mockResolvedValueOnce({
+                room_id: "!1:example.org",
+                delay_id: `id-${Math.random}`,
+            });
+            await expect(
+                client.sendEvent("!1:example.org", "org.matrix.rageshake_request", { request_id: 123 }),
+            ).rejects.toThrow();
+        });
+
         it("receives", async () => {
             const event = new MatrixEvent({
                 type: "org.matrix.rageshake_request",
@@ -160,6 +189,199 @@ describe("RoomWidgetClient", () => {
         });
     });
 
+    describe("delayed events", () => {
+        describe("when supported", () => {
+            const doesServerSupportUnstableFeatureMock = jest.fn((feature) =>
+                Promise.resolve(feature === "org.matrix.msc4140"),
+            );
+
+            beforeAll(() => {
+                MatrixClient.prototype.doesServerSupportUnstableFeature = doesServerSupportUnstableFeatureMock;
+            });
+
+            afterAll(() => {
+                doesServerSupportUnstableFeatureMock.mockReset();
+            });
+
+            it("sends delayed message events", async () => {
+                await makeClient({ sendDelayedEvents: true, sendEvent: ["org.matrix.rageshake_request"] });
+                expect(widgetApi.requestCapability).toHaveBeenCalledWith(MatrixCapabilities.MSC4157SendDelayedEvent);
+                await client._unstable_sendDelayedEvent(
+                    "!1:example.org",
+                    { delay: 2000 },
+                    null,
+                    "org.matrix.rageshake_request",
+                    { request_id: 123 },
+                );
+                expect(widgetApi.sendRoomEvent).toHaveBeenCalledWith(
+                    "org.matrix.rageshake_request",
+                    { request_id: 123 },
+                    "!1:example.org",
+                    2000,
+                    undefined,
+                );
+            });
+
+            it("sends child action delayed message events", async () => {
+                await makeClient({ sendDelayedEvents: true, sendEvent: ["org.matrix.rageshake_request"] });
+                expect(widgetApi.requestCapability).toHaveBeenCalledWith(MatrixCapabilities.MSC4157SendDelayedEvent);
+                const parentDelayId = `id-${Math.random()}`;
+                await client._unstable_sendDelayedEvent(
+                    "!1:example.org",
+                    { parent_delay_id: parentDelayId },
+                    null,
+                    "org.matrix.rageshake_request",
+                    { request_id: 123 },
+                );
+                expect(widgetApi.sendRoomEvent).toHaveBeenCalledWith(
+                    "org.matrix.rageshake_request",
+                    { request_id: 123 },
+                    "!1:example.org",
+                    undefined,
+                    parentDelayId,
+                );
+            });
+
+            it("sends delayed state events", async () => {
+                await makeClient({
+                    sendDelayedEvents: true,
+                    sendState: [{ eventType: "org.example.foo", stateKey: "bar" }],
+                });
+                expect(widgetApi.requestCapability).toHaveBeenCalledWith(MatrixCapabilities.MSC4157SendDelayedEvent);
+                await client._unstable_sendDelayedStateEvent(
+                    "!1:example.org",
+                    { delay: 2000 },
+                    "org.example.foo",
+                    { hello: "world" },
+                    "bar",
+                );
+                expect(widgetApi.sendStateEvent).toHaveBeenCalledWith(
+                    "org.example.foo",
+                    "bar",
+                    { hello: "world" },
+                    "!1:example.org",
+                    2000,
+                    undefined,
+                );
+            });
+
+            it("sends child action delayed state events", async () => {
+                await makeClient({
+                    sendDelayedEvents: true,
+                    sendState: [{ eventType: "org.example.foo", stateKey: "bar" }],
+                });
+                expect(widgetApi.requestCapability).toHaveBeenCalledWith(MatrixCapabilities.MSC4157SendDelayedEvent);
+                const parentDelayId = `fg-${Math.random()}`;
+                await client._unstable_sendDelayedStateEvent(
+                    "!1:example.org",
+                    { parent_delay_id: parentDelayId },
+                    "org.example.foo",
+                    { hello: "world" },
+                    "bar",
+                );
+                expect(widgetApi.sendStateEvent).toHaveBeenCalledWith(
+                    "org.example.foo",
+                    "bar",
+                    { hello: "world" },
+                    "!1:example.org",
+                    undefined,
+                    parentDelayId,
+                );
+            });
+
+            it("send delayed message events handles wrong field in response", async () => {
+                await makeClient({ sendDelayedEvents: true, sendEvent: ["org.matrix.rageshake_request"] });
+                widgetApi.sendRoomEvent.mockResolvedValueOnce({
+                    room_id: "!1:example.org",
+                    event_id: `$${Math.random()}`,
+                });
+                await expect(
+                    client._unstable_sendDelayedEvent(
+                        "!1:example.org",
+                        { delay: 2000 },
+                        null,
+                        "org.matrix.rageshake_request",
+                        { request_id: 123 },
+                    ),
+                ).rejects.toThrow();
+            });
+
+            it("send delayed state events handles wrong field in response", async () => {
+                await makeClient({
+                    sendDelayedEvents: true,
+                    sendState: [{ eventType: "org.example.foo", stateKey: "bar" }],
+                });
+                widgetApi.sendStateEvent.mockResolvedValueOnce({
+                    room_id: "!1:example.org",
+                    event_id: `$${Math.random()}`,
+                });
+                await expect(
+                    client._unstable_sendDelayedStateEvent(
+                        "!1:example.org",
+                        { delay: 2000 },
+                        "org.example.foo",
+                        { hello: "world" },
+                        "bar",
+                    ),
+                ).rejects.toThrow();
+            });
+
+            it("updates delayed events", async () => {
+                await makeClient({ updateDelayedEvents: true, sendEvent: ["org.matrix.rageshake_request"] });
+                expect(widgetApi.requestCapability).toHaveBeenCalledWith(MatrixCapabilities.MSC4157UpdateDelayedEvent);
+                for (const action of [
+                    UpdateDelayedEventAction.Cancel,
+                    UpdateDelayedEventAction.Restart,
+                    UpdateDelayedEventAction.Send,
+                ]) {
+                    await client._unstable_updateDelayedEvent("id", action);
+                    expect(widgetApi.updateDelayedEvent).toHaveBeenCalledWith("id", action);
+                }
+            });
+        });
+
+        describe("when unsupported", () => {
+            it("fails to send delayed message events", async () => {
+                await makeClient({ sendEvent: ["org.matrix.rageshake_request"] });
+                await expect(
+                    client._unstable_sendDelayedEvent(
+                        "!1:example.org",
+                        { delay: 2000 },
+                        null,
+                        "org.matrix.rageshake_request",
+                        { request_id: 123 },
+                    ),
+                ).rejects.toThrow("Server does not support");
+            });
+
+            it("fails to send delayed state events", async () => {
+                await makeClient({ sendState: [{ eventType: "org.example.foo", stateKey: "bar" }] });
+                await expect(
+                    client._unstable_sendDelayedStateEvent(
+                        "!1:example.org",
+                        { delay: 2000 },
+                        "org.example.foo",
+                        { hello: "world" },
+                        "bar",
+                    ),
+                ).rejects.toThrow("Server does not support");
+            });
+
+            it("fails to update delayed state events", async () => {
+                await makeClient({});
+                for (const action of [
+                    UpdateDelayedEventAction.Cancel,
+                    UpdateDelayedEventAction.Restart,
+                    UpdateDelayedEventAction.Send,
+                ]) {
+                    await expect(client._unstable_updateDelayedEvent("id", action)).rejects.toThrow(
+                        "Server does not support",
+                    );
+                }
+            });
+        });
+    });
+
     describe("initialization", () => {
         it("requests permissions for specific message types", async () => {
             await makeClient({ sendMessage: [MsgType.Text], receiveMessage: [MsgType.Text] });
@@ -211,6 +433,17 @@ describe("RoomWidgetClient", () => {
             );
         });
 
+        it("send handles incorrect response", async () => {
+            await makeClient({ sendState: [{ eventType: "org.example.foo", stateKey: "bar" }] });
+            widgetApi.sendStateEvent.mockResolvedValueOnce({
+                room_id: "!1:example.org",
+                delay_id: `id-${Math.random}`,
+            });
+            await expect(
+                client.sendStateEvent("!1:example.org", "org.example.foo", { hello: "world" }, "bar"),
+            ).rejects.toThrow();
+        });
+
         it("receives", async () => {
             await makeClient({ receiveState: [{ eventType: "org.example.foo", stateKey: "bar" }] });
             expect(widgetApi.requestCapabilityForRoomTimeline).toHaveBeenCalledWith("!1:example.org");

spec/unit/matrix-client.spec.ts

@@ -57,6 +57,7 @@ import {
     Room,
     RuleId,
     TweakName,
+    UpdateDelayedEventAction,
 } from "../../src";
 import { supportsMatrixCall } from "../../src/webrtc/call";
 import { makeBeaconEvent } from "../test-utils/beacon";
@@ -97,7 +98,7 @@ type HttpLookup = {
     method: string;
     path: string;
     prefix?: string;
-    data?: Record<string, any>;
+    data?: Record<string, any> | Record<string, any>[];
     error?: object;
     expectBody?: Record<string, any>;
     expectQueryParams?: QueryDict;
@@ -298,7 +299,9 @@ describe("MatrixClient", function () {
             ...(opts || {}),
         });
         // FIXME: We shouldn't be yanking http like this.
-        client.http = (["authedRequest", "getContentUri", "request", "uploadContent"] as const).reduce((r, k) => {
+        client.http = (
+            ["authedRequest", "getContentUri", "request", "uploadContent", "idServerRequest"] as const
+        ).reduce((r, k) => {
             r[k] = jest.fn();
             return r;
         }, {} as MatrixHttpApi<any>);
@@ -704,6 +707,328 @@ describe("MatrixClient", function () {
         });
     });
 
+    describe("_unstable_sendDelayedEvent", () => {
+        const unstableMSC4140Prefix = `${ClientPrefix.Unstable}/org.matrix.msc4140`;
+
+        const roomId = "!room:example.org";
+        const body = "This is the body";
+        const content = { body, msgtype: MsgType.Text } satisfies RoomMessageEventContent;
+        const timeoutDelayOpts = { delay: 2000 };
+        const realTimeoutDelayOpts = { "org.matrix.msc4140.delay": 2000 };
+
+        beforeEach(() => {
+            unstableFeatures["org.matrix.msc4140"] = true;
+        });
+
+        it("throws when unsupported by server", async () => {
+            unstableFeatures["org.matrix.msc4140"] = false;
+            const errorMessage = "Server does not support";
+
+            await expect(
+                client._unstable_sendDelayedEvent(
+                    roomId,
+                    timeoutDelayOpts,
+                    null,
+                    EventType.RoomMessage,
+                    { ...content },
+                    client.makeTxnId(),
+                ),
+            ).rejects.toThrow(errorMessage);
+
+            await expect(
+                client._unstable_sendDelayedStateEvent(roomId, timeoutDelayOpts, EventType.RoomTopic, {
+                    topic: "topic",
+                }),
+            ).rejects.toThrow(errorMessage);
+
+            await expect(client._unstable_getDelayedEvents()).rejects.toThrow(errorMessage);
+
+            await expect(
+                client._unstable_updateDelayedEvent("anyDelayId", UpdateDelayedEventAction.Send),
+            ).rejects.toThrow(errorMessage);
+        });
+
+        it("works with null threadId", async () => {
+            httpLookups = [];
+
+            const timeoutDelayTxnId = client.makeTxnId();
+            httpLookups.push({
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/send/m.room.message/${timeoutDelayTxnId}`,
+                expectQueryParams: realTimeoutDelayOpts,
+                data: { delay_id: "id1" },
+                expectBody: content,
+            });
+
+            const { delay_id: timeoutDelayId } = await client._unstable_sendDelayedEvent(
+                roomId,
+                timeoutDelayOpts,
+                null,
+                EventType.RoomMessage,
+                { ...content },
+                timeoutDelayTxnId,
+            );
+
+            const actionDelayTxnId = client.makeTxnId();
+            httpLookups.push({
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/send/m.room.message/${actionDelayTxnId}`,
+                expectQueryParams: { "org.matrix.msc4140.parent_delay_id": timeoutDelayId },
+                data: { delay_id: "id2" },
+                expectBody: content,
+            });
+
+            await client._unstable_sendDelayedEvent(
+                roomId,
+                { parent_delay_id: timeoutDelayId },
+                null,
+                EventType.RoomMessage,
+                { ...content },
+                actionDelayTxnId,
+            );
+        });
+
+        it("works with non-null threadId", async () => {
+            httpLookups = [];
+            const threadId = "$threadId:server";
+            const expectBody = {
+                ...content,
+                "m.relates_to": {
+                    event_id: threadId,
+                    is_falling_back: true,
+                    rel_type: "m.thread",
+                },
+            };
+
+            const timeoutDelayTxnId = client.makeTxnId();
+            httpLookups.push({
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/send/m.room.message/${timeoutDelayTxnId}`,
+                expectQueryParams: realTimeoutDelayOpts,
+                data: { delay_id: "id1" },
+                expectBody,
+            });
+
+            const { delay_id: timeoutDelayId } = await client._unstable_sendDelayedEvent(
+                roomId,
+                timeoutDelayOpts,
+                threadId,
+                EventType.RoomMessage,
+                { ...content },
+                timeoutDelayTxnId,
+            );
+
+            const actionDelayTxnId = client.makeTxnId();
+            httpLookups.push({
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/send/m.room.message/${actionDelayTxnId}`,
+                expectQueryParams: { "org.matrix.msc4140.parent_delay_id": timeoutDelayId },
+                data: { delay_id: "id2" },
+                expectBody,
+            });
+
+            await client._unstable_sendDelayedEvent(
+                roomId,
+                { parent_delay_id: timeoutDelayId },
+                threadId,
+                EventType.RoomMessage,
+                { ...content },
+                actionDelayTxnId,
+            );
+        });
+
+        it("should add thread relation if threadId is passed and the relation is missing", async () => {
+            httpLookups = [];
+            const threadId = "$threadId:server";
+            const expectBody = {
+                ...content,
+                "m.relates_to": {
+                    "m.in_reply_to": {
+                        event_id: threadId,
+                    },
+                    "event_id": threadId,
+                    "is_falling_back": true,
+                    "rel_type": "m.thread",
+                },
+            };
+
+            const room = new Room(roomId, client, userId);
+            mocked(store.getRoom).mockReturnValue(room);
+
+            const rootEvent = new MatrixEvent({ event_id: threadId });
+            room.createThread(threadId, rootEvent, [rootEvent], false);
+
+            const timeoutDelayTxnId = client.makeTxnId();
+            httpLookups.push({
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/send/m.room.message/${timeoutDelayTxnId}`,
+                expectQueryParams: realTimeoutDelayOpts,
+                data: { delay_id: "id1" },
+                expectBody,
+            });
+
+            const { delay_id: timeoutDelayId } = await client._unstable_sendDelayedEvent(
+                roomId,
+                timeoutDelayOpts,
+                threadId,
+                EventType.RoomMessage,
+                { ...content },
+                timeoutDelayTxnId,
+            );
+
+            const actionDelayTxnId = client.makeTxnId();
+            httpLookups.push({
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/send/m.room.message/${actionDelayTxnId}`,
+                expectQueryParams: { "org.matrix.msc4140.parent_delay_id": timeoutDelayId },
+                data: { delay_id: "id2" },
+                expectBody,
+            });
+
+            await client._unstable_sendDelayedEvent(
+                roomId,
+                { parent_delay_id: timeoutDelayId },
+                threadId,
+                EventType.RoomMessage,
+                { ...content },
+                actionDelayTxnId,
+            );
+        });
+
+        it("should add thread relation if threadId is passed and the relation is missing with reply", async () => {
+            httpLookups = [];
+            const threadId = "$threadId:server";
+
+            const content = {
+                body,
+                "msgtype": MsgType.Text,
+                "m.relates_to": {
+                    "m.in_reply_to": {
+                        event_id: "$other:event",
+                    },
+                },
+            } satisfies RoomMessageEventContent;
+            const expectBody = {
+                ...content,
+                "m.relates_to": {
+                    "m.in_reply_to": {
+                        event_id: "$other:event",
+                    },
+                    "event_id": threadId,
+                    "is_falling_back": false,
+                    "rel_type": "m.thread",
+                },
+            };
+
+            const room = new Room(roomId, client, userId);
+            mocked(store.getRoom).mockReturnValue(room);
+
+            const rootEvent = new MatrixEvent({ event_id: threadId });
+            room.createThread(threadId, rootEvent, [rootEvent], false);
+
+            const timeoutDelayTxnId = client.makeTxnId();
+            httpLookups.push({
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/send/m.room.message/${timeoutDelayTxnId}`,
+                expectQueryParams: realTimeoutDelayOpts,
+                data: { delay_id: "id1" },
+                expectBody,
+            });
+
+            const { delay_id: timeoutDelayId } = await client._unstable_sendDelayedEvent(
+                roomId,
+                timeoutDelayOpts,
+                threadId,
+                EventType.RoomMessage,
+                { ...content },
+                timeoutDelayTxnId,
+            );
+
+            const actionDelayTxnId = client.makeTxnId();
+            httpLookups.push({
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/send/m.room.message/${actionDelayTxnId}`,
+                expectQueryParams: { "org.matrix.msc4140.parent_delay_id": timeoutDelayId },
+                data: { delay_id: "id2" },
+                expectBody,
+            });
+
+            await client._unstable_sendDelayedEvent(
+                roomId,
+                { parent_delay_id: timeoutDelayId },
+                threadId,
+                EventType.RoomMessage,
+                { ...content },
+                actionDelayTxnId,
+            );
+        });
+
+        it("can send a delayed state event", async () => {
+            httpLookups = [];
+            const content = { topic: "The year 2000" };
+
+            httpLookups.push({
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/state/m.room.topic/`,
+                expectQueryParams: realTimeoutDelayOpts,
+                data: { delay_id: "id1" },
+                expectBody: content,
+            });
+
+            const { delay_id: timeoutDelayId } = await client._unstable_sendDelayedStateEvent(
+                roomId,
+                timeoutDelayOpts,
+                EventType.RoomTopic,
+                { ...content },
+            );
+
+            httpLookups.push({
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/state/m.room.topic/`,
+                expectQueryParams: { "org.matrix.msc4140.parent_delay_id": timeoutDelayId },
+                data: { delay_id: "id2" },
+                expectBody: content,
+            });
+
+            await client._unstable_sendDelayedStateEvent(
+                roomId,
+                { parent_delay_id: timeoutDelayId },
+                EventType.RoomTopic,
+                { ...content },
+            );
+        });
+
+        it("can look up delayed events", async () => {
+            httpLookups = [
+                {
+                    method: "GET",
+                    prefix: unstableMSC4140Prefix,
+                    path: "/delayed_events",
+                    data: [],
+                },
+            ];
+
+            await client._unstable_getDelayedEvents();
+        });
+
+        it("can update delayed events", async () => {
+            const delayId = "id";
+            const action = UpdateDelayedEventAction.Restart;
+            httpLookups = [
+                {
+                    method: "POST",
+                    prefix: unstableMSC4140Prefix,
+                    path: `/delayed_events/${encodeURIComponent(delayId)}`,
+                    data: {
+                        action,
+                    },
+                },
+            ];
+
+            await client._unstable_updateDelayedEvent(delayId, action);
+        });
+    });
+
     it("should create (unstable) file trees", async () => {
         const userId = "@test:example.org";
         const roomId = "!room:example.org";
@@ -963,7 +1288,7 @@ describe("MatrixClient", function () {
             const filter = new Filter(client.credentials.userId);
 
             const filterId = await client.getOrCreateFilter(filterName, filter);
-            expect(filterId).toEqual(FILTER_RESPONSE.data?.filter_id);
+            expect(filterId).toEqual(!Array.isArray(FILTER_RESPONSE.data) && FILTER_RESPONSE.data?.filter_id);
         });
     });
 
@@ -3035,4 +3360,45 @@ describe("MatrixClient", function () {
             expect(httpLookups.length).toEqual(0);
         });
     });
+
+    describe("identityHashedLookup", () => {
+        it("should return hashed lookup results", async () => {
+            const ID_ACCESS_TOKEN = "hello_id_server_please_let_me_make_a_request";
+
+            client.http.idServerRequest = jest.fn().mockImplementation((method, path, params) => {
+                if (method === "GET" && path === "/hash_details") {
+                    return { algorithms: ["sha256"], lookup_pepper: "carrot" };
+                } else if (method === "POST" && path === "/lookup") {
+                    return {
+                        mappings: {
+                            "WHA-MgrrsZACDI9F8OaVagpiyiV2sjZylGHJteT4OMU": "@bob:homeserver.dummy",
+                        },
+                    };
+                }
+
+                throw new Error("Test impl doesn't know about this request");
+            });
+
+            const lookupResult = await client.identityHashedLookup([["bob@email.dummy", "email"]], ID_ACCESS_TOKEN);
+
+            expect(client.http.idServerRequest).toHaveBeenCalledWith(
+                "GET",
+                "/hash_details",
+                undefined,
+                "/_matrix/identity/v2",
+                ID_ACCESS_TOKEN,
+            );
+
+            expect(client.http.idServerRequest).toHaveBeenCalledWith(
+                "POST",
+                "/lookup",
+                { pepper: "carrot", algorithm: "sha256", addresses: ["WHA-MgrrsZACDI9F8OaVagpiyiV2sjZylGHJteT4OMU"] },
+                "/_matrix/identity/v2",
+                ID_ACCESS_TOKEN,
+            );
+
+            expect(lookupResult).toHaveLength(1);
+            expect(lookupResult[0]).toEqual({ address: "bob@email.dummy", mxid: "@bob:homeserver.dummy" });
+        });
+    });
 });

spec/unit/matrixrtc/CallMembership.spec.ts

@@ -98,20 +98,6 @@ describe("CallMembership", () => {
             expect(membership.getAbsoluteExpiry()).toEqual(5000 + 1000);
         });
 
-        it("considers memberships unexpired if local age low enough", () => {
-            const fakeEvent = makeMockEvent(1000);
-            fakeEvent.getLocalAge = jest.fn().mockReturnValue(3000);
-            const membership = new CallMembership(fakeEvent, membershipTemplate);
-            expect(membership.isExpired()).toEqual(false);
-        });
-
-        it("considers memberships expired when local age large", () => {
-            const fakeEvent = makeMockEvent(1000);
-            fakeEvent.localTimestamp = Date.now() - 6000;
-            const membership = new CallMembership(fakeEvent, membershipTemplate);
-            expect(membership.isExpired()).toEqual(true);
-        });
-
         it("returns preferred foci", () => {
             const fakeEvent = makeMockEvent();
             const mockFocus = { type: "this_is_a_mock_focus" };
@@ -198,13 +184,6 @@ describe("CallMembership", () => {
         beforeEach(() => {
             // server origin timestamp for this event is 1000
             fakeEvent = makeMockEvent(1000);
-            // our clock would have been at 2000 at the creation time (our clock at event receive time - age)
-            // (ie. the local clock is 1 second ahead of the servers' clocks)
-            fakeEvent.localTimestamp = 2000;
-
-            // for simplicity's sake, we say that the event's age is zero
-            fakeEvent.getLocalAge = jest.fn().mockReturnValue(0);
-
             membership = new CallMembership(fakeEvent!, membershipTemplate);
 
             jest.useFakeTimers();
@@ -215,6 +194,13 @@ describe("CallMembership", () => {
         });
 
         it("converts expiry time into local clock", () => {
+            // our clock would have been at 2000 at the creation time (our clock at event receive time - age)
+            // (ie. the local clock is 1 second ahead of the servers' clocks)
+            fakeEvent.localTimestamp = 2000;
+
+            // for simplicity's sake, we say that the event's age is zero
+            fakeEvent.getLocalAge = jest.fn().mockReturnValue(0);
+
             // for sanity's sake, make sure the server-relative expiry time is what we expect
             expect(membership.getAbsoluteExpiry()).toEqual(6000);
             // therefore the expiry time converted to our clock should be 1 second later
@@ -223,7 +209,8 @@ describe("CallMembership", () => {
 
         it("calculates time until expiry", () => {
             jest.setSystemTime(2000);
-            expect(membership.getMsUntilExpiry()).toEqual(5000);
+            // should be using absolute expiry time
+            expect(membership.getMsUntilExpiry()).toEqual(4000);
         });
     });
 });

spec/unit/matrixrtc/MatrixRTCSession.spec.ts

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { EventTimeline, EventType, MatrixClient, MatrixError, MatrixEvent, Room } from "../../../src";
+import { encodeBase64, EventTimeline, EventType, MatrixClient, MatrixError, MatrixEvent, Room } from "../../../src";
 import { KnownMembership } from "../../../src/@types/membership";
 import {
     CallMembershipData,
@@ -46,6 +46,9 @@ describe("MatrixRTCSession", () => {
         client = new MatrixClient({ baseUrl: "base_url" });
         client.getUserId = jest.fn().mockReturnValue("@alice:example.org");
         client.getDeviceId = jest.fn().mockReturnValue("AAAAAAA");
+        client.doesServerSupportUnstableFeature = jest.fn((feature) =>
+            Promise.resolve(feature === "org.matrix.msc4140"),
+        );
     });
 
     afterEach(() => {
@@ -70,14 +73,17 @@ describe("MatrixRTCSession", () => {
     });
 
     it("ignores expired memberships events", () => {
+        jest.useFakeTimers();
         const expiredMembership = Object.assign({}, membershipTemplate);
         expiredMembership.expires = 1000;
         expiredMembership.device_id = "EXPIRED";
-        const mockRoom = makeMockRoom([membershipTemplate, expiredMembership], 10000);
+        const mockRoom = makeMockRoom([membershipTemplate, expiredMembership]);
 
+        jest.advanceTimersByTime(2000);
         sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
         expect(sess?.memberships.length).toEqual(1);
         expect(sess?.memberships[0].deviceId).toEqual("AAAAAAA");
+        jest.useRealTimers();
     });
 
     it("ignores memberships events of members not in the room", () => {
@@ -88,12 +94,15 @@ describe("MatrixRTCSession", () => {
     });
 
     it("honours created_ts", () => {
+        jest.useFakeTimers();
+        jest.setSystemTime(500);
         const expiredMembership = Object.assign({}, membershipTemplate);
         expiredMembership.created_ts = 500;
         expiredMembership.expires = 1000;
         const mockRoom = makeMockRoom([expiredMembership]);
         sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
         expect(sess?.memberships[0].getAbsoluteExpiry()).toEqual(1500);
+        jest.useRealTimers();
     });
 
     it("returns empty session if no membership events are present", () => {
@@ -241,40 +250,68 @@ describe("MatrixRTCSession", () => {
             foci_preferred: [mockFocus],
         };
 
-        function testSession(
+        let sendStateEventMock: jest.Mock;
+        let sendDelayedStateMock: jest.Mock;
+
+        let sentStateEvent: Promise<void>;
+        let sentDelayedState: Promise<void>;
+
+        beforeEach(() => {
+            sentStateEvent = new Promise((resolve) => {
+                sendStateEventMock = jest.fn(resolve);
+            });
+            sentDelayedState = new Promise((resolve) => {
+                sendDelayedStateMock = jest.fn(() => {
+                    resolve();
+                    return {
+                        delay_id: "id",
+                    };
+                });
+            });
+            client.sendStateEvent = sendStateEventMock;
+            client._unstable_sendDelayedStateEvent = sendDelayedStateMock;
+        });
+
+        async function testSession(
             membershipData: CallMembershipData[] | SessionMembershipData,
             shouldUseLegacy: boolean,
-        ): void {
+        ): Promise<void> {
             sess = MatrixRTCSession.roomSessionForRoom(client, makeMockRoom(membershipData));
 
             const makeNewLegacyMembershipsMock = jest.spyOn(sess as any, "makeNewLegacyMemberships");
             const makeNewMembershipMock = jest.spyOn(sess as any, "makeNewMembership");
 
             sess.joinRoomSession([mockFocus], mockFocus, joinSessionConfig);
+            await Promise.race([sentStateEvent, new Promise((resolve) => setTimeout(resolve, 500))]);
 
             expect(makeNewLegacyMembershipsMock).toHaveBeenCalledTimes(shouldUseLegacy ? 1 : 0);
             expect(makeNewMembershipMock).toHaveBeenCalledTimes(shouldUseLegacy ? 0 : 1);
+
+            await Promise.race([sentDelayedState, new Promise((resolve) => setTimeout(resolve, 500))]);
+            expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledTimes(shouldUseLegacy ? 0 : 1);
         }
 
-        it("uses legacy events if there are any active legacy calls", () => {
-            testSession([expiredLegacyMembershipData, legacyMembershipData, sessionMembershipData], true);
+        it("uses legacy events if there are any active legacy calls", async () => {
+            await testSession([expiredLegacyMembershipData, legacyMembershipData, sessionMembershipData], true);
         });
 
-        it('uses legacy events if a non-legacy call is in a "memberships" array', () => {
-            testSession([sessionMembershipData], true);
+        it('uses legacy events if a non-legacy call is in a "memberships" array', async () => {
+            await testSession([sessionMembershipData], true);
         });
 
-        it("uses non-legacy events if all legacy calls are expired", () => {
-            testSession([expiredLegacyMembershipData], false);
+        it("uses non-legacy events if all legacy calls are expired", async () => {
+            await testSession([expiredLegacyMembershipData], false);
         });
 
-        it("uses non-legacy events if there are only non-legacy calls", () => {
-            testSession(sessionMembershipData, false);
+        it("uses non-legacy events if there are only non-legacy calls", async () => {
+            await testSession(sessionMembershipData, false);
         });
     });
 
     describe("getOldestMembership", () => {
         it("returns the oldest membership event", () => {
+            jest.useFakeTimers();
+            jest.setSystemTime(4000);
             const mockRoom = makeMockRoom([
                 Object.assign({}, membershipTemplate, { device_id: "foo", created_ts: 3000 }),
                 Object.assign({}, membershipTemplate, { device_id: "old", created_ts: 1000 }),
@@ -283,12 +320,15 @@ describe("MatrixRTCSession", () => {
 
             sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
             expect(sess.getOldestMembership()!.deviceId).toEqual("old");
+            jest.useRealTimers();
         });
     });
 
     describe("getsActiveFocus", () => {
         const activeFociConfig = { type: "livekit", livekit_service_url: "https://active.url" };
         it("gets the correct active focus with oldest_membership", () => {
+            jest.useFakeTimers();
+            jest.setSystemTime(3000);
             const mockRoom = makeMockRoom([
                 Object.assign({}, membershipTemplate, {
                     device_id: "foo",
@@ -306,6 +346,7 @@ describe("MatrixRTCSession", () => {
                 focus_selection: "oldest_membership",
             });
             expect(sess.getActiveFocus()).toBe(activeFociConfig);
+            jest.useRealTimers();
         });
         it("does not provide focus if the selction method is unknown", () => {
             const mockRoom = makeMockRoom([
@@ -327,6 +368,8 @@ describe("MatrixRTCSession", () => {
             expect(sess.getActiveFocus()).toBe(undefined);
         });
         it("gets the correct active focus legacy", () => {
+            jest.useFakeTimers();
+            jest.setSystemTime(3000);
             const mockRoom = makeMockRoom([
                 Object.assign({}, membershipTemplate, {
                     device_id: "foo",
@@ -341,18 +384,34 @@ describe("MatrixRTCSession", () => {
 
             sess.joinRoomSession([{ type: "livekit", livekit_service_url: "htts://test.org" }]);
             expect(sess.getActiveFocus()).toBe(activeFociConfig);
+            jest.useRealTimers();
         });
     });
 
     describe("joining", () => {
         let mockRoom: Room;
         let sendStateEventMock: jest.Mock;
+        let sendDelayedStateMock: jest.Mock;
         let sendEventMock: jest.Mock;
 
+        let sentStateEvent: Promise<void>;
+        let sentDelayedState: Promise<void>;
+
         beforeEach(() => {
-            sendStateEventMock = jest.fn();
+            sentStateEvent = new Promise((resolve) => {
+                sendStateEventMock = jest.fn(resolve);
+            });
+            sentDelayedState = new Promise((resolve) => {
+                sendDelayedStateMock = jest.fn(() => {
+                    resolve();
+                    return {
+                        delay_id: "id",
+                    };
+                });
+            });
             sendEventMock = jest.fn();
             client.sendStateEvent = sendStateEventMock;
+            client._unstable_sendDelayedStateEvent = sendDelayedStateMock;
             client.sendEvent = sendEventMock;
 
             mockRoom = makeMockRoom([]);
@@ -373,9 +432,11 @@ describe("MatrixRTCSession", () => {
             expect(sess!.isJoined()).toEqual(true);
         });
 
-        it("sends a membership event when joining a call", () => {
+        it("sends a membership event when joining a call", async () => {
+            const realSetTimeout = setTimeout;
             jest.useFakeTimers();
             sess!.joinRoomSession([mockFocus], mockFocus);
+            await Promise.race([sentStateEvent, new Promise((resolve) => realSetTimeout(resolve, 500))]);
             expect(client.sendStateEvent).toHaveBeenCalledWith(
                 mockRoom!.roomId,
                 EventType.GroupCallMemberPrefix,
@@ -396,6 +457,8 @@ describe("MatrixRTCSession", () => {
                 },
                 "@alice:example.org",
             );
+            await Promise.race([sentDelayedState, new Promise((resolve) => realSetTimeout(resolve, 500))]);
+            expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledTimes(0);
             jest.useRealTimers();
         });
 
@@ -403,13 +466,15 @@ describe("MatrixRTCSession", () => {
             const activeFocusConfig = { type: "livekit", livekit_service_url: "https://active.url" };
             const activeFocus = { type: "livekit", focus_selection: "oldest_membership" };
 
-            function testJoin(useOwnedStateEvents: boolean): void {
+            async function testJoin(useOwnedStateEvents: boolean): Promise<void> {
+                const realSetTimeout = setTimeout;
                 if (useOwnedStateEvents) {
                     mockRoom.getVersion = jest.fn().mockReturnValue("org.matrix.msc3779.default");
                 }
 
                 jest.useFakeTimers();
                 sess!.joinRoomSession([activeFocusConfig], activeFocus, { useLegacyMemberEvents: false });
+                await Promise.race([sentStateEvent, new Promise((resolve) => realSetTimeout(resolve, 500))]);
                 expect(client.sendStateEvent).toHaveBeenCalledWith(
                     mockRoom!.roomId,
                     EventType.GroupCallMemberPrefix,
@@ -423,15 +488,17 @@ describe("MatrixRTCSession", () => {
                     } satisfies SessionMembershipData,
                     `${!useOwnedStateEvents ? "_" : ""}@alice:example.org_AAAAAAA`,
                 );
+                await Promise.race([sentDelayedState, new Promise((resolve) => realSetTimeout(resolve, 500))]);
+                expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledTimes(1);
                 jest.useRealTimers();
             }
 
-            it("sends a membership event with session payload when joining a non-legacy call", () => {
-                testJoin(false);
+            it("sends a membership event with session payload when joining a non-legacy call", async () => {
+                await testJoin(false);
             });
 
-            it("does not prefix the state key with _ for rooms that support user-owned state events", () => {
-                testJoin(true);
+            it("does not prefix the state key with _ for rooms that support user-owned state events", async () => {
+                await testJoin(true);
             });
         });
 
@@ -461,9 +528,8 @@ describe("MatrixRTCSession", () => {
 
                 const eventContent = await eventSentPromise;
 
-                // definitely should have renewed by 1 second before the expiry!
-                const timeElapsed = 60 * 60 * 1000 - 1000;
-                const event = mockRTCEvent(eventContent.memberships, mockRoom.roomId, timeElapsed);
+                jest.setSystemTime(1000);
+                const event = mockRTCEvent(eventContent.memberships, mockRoom.roomId);
                 const getState = mockRoom.getLiveTimeline().getState(EventTimeline.FORWARDS)!;
                 getState.getStateEvents = jest.fn().mockReturnValue(event);
                 getState.events = new Map([
@@ -486,6 +552,8 @@ describe("MatrixRTCSession", () => {
 
                 sendStateEventMock.mockReset().mockImplementation(resolveFn);
 
+                // definitely should have renewed by 1 second before the expiry!
+                const timeElapsed = 60 * 60 * 1000 - 1000;
                 jest.setSystemTime(Date.now() + timeElapsed);
                 jest.advanceTimersByTime(timeElapsed);
                 await eventReSentPromise;
@@ -546,6 +614,17 @@ describe("MatrixRTCSession", () => {
             });
         });
 
+        it("does not send key if join called when already joined", () => {
+            sess!.joinRoomSession([mockFocus], mockFocus, { manageMediaKeys: true });
+
+            expect(client.sendStateEvent).toHaveBeenCalledTimes(1);
+            expect(client.sendEvent).toHaveBeenCalledTimes(1);
+
+            sess!.joinRoomSession([mockFocus], mockFocus, { manageMediaKeys: true });
+            expect(client.sendStateEvent).toHaveBeenCalledTimes(1);
+            expect(client.sendEvent).toHaveBeenCalledTimes(1);
+        });
+
         it("retries key sends", async () => {
             jest.useFakeTimers();
             let firstEventSent = false;
@@ -622,7 +701,7 @@ describe("MatrixRTCSession", () => {
 
                 mockRoom.getLiveTimeline().getState = jest
                     .fn()
-                    .mockReturnValue(makeMockRoomState([membershipTemplate, member2], mockRoom.roomId, undefined));
+                    .mockReturnValue(makeMockRoomState([membershipTemplate, member2], mockRoom.roomId));
                 sess.onMembershipUpdate();
 
                 await keysSentPromise2;
@@ -633,6 +712,214 @@ describe("MatrixRTCSession", () => {
             }
         });
 
+        it("Does not re-send key if memberships stays same", async () => {
+            jest.useFakeTimers();
+            try {
+                const keysSentPromise1 = new Promise((resolve) => {
+                    sendEventMock.mockImplementation(resolve);
+                });
+
+                const member1 = membershipTemplate;
+                const member2 = Object.assign({}, membershipTemplate, {
+                    device_id: "BBBBBBB",
+                });
+
+                const mockRoom = makeMockRoom([member1, member2]);
+                mockRoom.getLiveTimeline().getState = jest
+                    .fn()
+                    .mockReturnValue(makeMockRoomState([member1, member2], mockRoom.roomId));
+
+                sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
+                sess.joinRoomSession([mockFocus], mockFocus, { manageMediaKeys: true });
+
+                await keysSentPromise1;
+
+                // make sure an encryption key was sent
+                expect(sendEventMock).toHaveBeenCalledWith(
+                    expect.stringMatching(".*"),
+                    "io.element.call.encryption_keys",
+                    {
+                        call_id: "",
+                        device_id: "AAAAAAA",
+                        keys: [
+                            {
+                                index: 0,
+                                key: expect.stringMatching(".*"),
+                            },
+                        ],
+                    },
+                );
+
+                sendEventMock.mockClear();
+
+                // these should be a no-op:
+                sess.onMembershipUpdate();
+                expect(sendEventMock).toHaveBeenCalledTimes(0);
+            } finally {
+                jest.useRealTimers();
+            }
+        });
+
+        it("Re-sends key if a member changes membership ID", async () => {
+            jest.useFakeTimers();
+            try {
+                const keysSentPromise1 = new Promise((resolve) => {
+                    sendEventMock.mockImplementation(resolve);
+                });
+
+                const member1 = membershipTemplate;
+                const member2 = {
+                    ...membershipTemplate,
+                    device_id: "BBBBBBB",
+                };
+
+                const mockRoom = makeMockRoom([member1, member2]);
+                mockRoom.getLiveTimeline().getState = jest
+                    .fn()
+                    .mockReturnValue(makeMockRoomState([member1, member2], mockRoom.roomId));
+
+                sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
+                sess.joinRoomSession([mockFocus], mockFocus, { manageMediaKeys: true });
+
+                await keysSentPromise1;
+
+                // make sure an encryption key was sent
+                expect(sendEventMock).toHaveBeenCalledWith(
+                    expect.stringMatching(".*"),
+                    "io.element.call.encryption_keys",
+                    {
+                        call_id: "",
+                        device_id: "AAAAAAA",
+                        keys: [
+                            {
+                                index: 0,
+                                key: expect.stringMatching(".*"),
+                            },
+                        ],
+                    },
+                );
+
+                sendEventMock.mockClear();
+
+                // this should be a no-op:
+                sess.onMembershipUpdate();
+                expect(sendEventMock).toHaveBeenCalledTimes(0);
+
+                // advance time to avoid key throttling
+                jest.advanceTimersByTime(10000);
+
+                // update membership ID
+                member2.membershipID = "newID";
+
+                const keysSentPromise2 = new Promise((resolve) => {
+                    sendEventMock.mockImplementation(resolve);
+                });
+
+                // this should re-send the key
+                sess.onMembershipUpdate();
+
+                await keysSentPromise2;
+
+                expect(sendEventMock).toHaveBeenCalledWith(
+                    expect.stringMatching(".*"),
+                    "io.element.call.encryption_keys",
+                    {
+                        call_id: "",
+                        device_id: "AAAAAAA",
+                        keys: [
+                            {
+                                index: 0,
+                                key: expect.stringMatching(".*"),
+                            },
+                        ],
+                    },
+                );
+            } finally {
+                jest.useRealTimers();
+            }
+        });
+
+        it("Re-sends key if a member changes created_ts", async () => {
+            jest.useFakeTimers();
+            jest.setSystemTime(1000);
+            try {
+                const keysSentPromise1 = new Promise((resolve) => {
+                    sendEventMock.mockImplementation(resolve);
+                });
+
+                const member1 = { ...membershipTemplate, created_ts: 1000 };
+                const member2 = {
+                    ...membershipTemplate,
+                    created_ts: 1000,
+                    device_id: "BBBBBBB",
+                };
+
+                const mockRoom = makeMockRoom([member1, member2]);
+                mockRoom.getLiveTimeline().getState = jest
+                    .fn()
+                    .mockReturnValue(makeMockRoomState([member1, member2], mockRoom.roomId));
+
+                sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
+                sess.joinRoomSession([mockFocus], mockFocus, { manageMediaKeys: true });
+
+                await keysSentPromise1;
+
+                // make sure an encryption key was sent
+                expect(sendEventMock).toHaveBeenCalledWith(
+                    expect.stringMatching(".*"),
+                    "io.element.call.encryption_keys",
+                    {
+                        call_id: "",
+                        device_id: "AAAAAAA",
+                        keys: [
+                            {
+                                index: 0,
+                                key: expect.stringMatching(".*"),
+                            },
+                        ],
+                    },
+                );
+
+                sendEventMock.mockClear();
+
+                // this should be a no-op:
+                sess.onMembershipUpdate();
+                expect(sendEventMock).toHaveBeenCalledTimes(0);
+
+                // advance time to avoid key throttling
+                jest.advanceTimersByTime(10000);
+
+                // update created_ts
+                member2.created_ts = 5000;
+
+                const keysSentPromise2 = new Promise((resolve) => {
+                    sendEventMock.mockImplementation(resolve);
+                });
+
+                // this should re-send the key
+                sess.onMembershipUpdate();
+
+                await keysSentPromise2;
+
+                expect(sendEventMock).toHaveBeenCalledWith(
+                    expect.stringMatching(".*"),
+                    "io.element.call.encryption_keys",
+                    {
+                        call_id: "",
+                        device_id: "AAAAAAA",
+                        keys: [
+                            {
+                                index: 0,
+                                key: expect.stringMatching(".*"),
+                            },
+                        ],
+                    },
+                );
+            } finally {
+                jest.useRealTimers();
+            }
+        });
+
         it("Rotates key if a member leaves", async () => {
             jest.useFakeTimers();
             try {
@@ -668,7 +955,7 @@ describe("MatrixRTCSession", () => {
 
                 mockRoom.getLiveTimeline().getState = jest
                     .fn()
-                    .mockReturnValue(makeMockRoomState([membershipTemplate], mockRoom.roomId, undefined));
+                    .mockReturnValue(makeMockRoomState([membershipTemplate], mockRoom.roomId));
                 sess.onMembershipUpdate();
 
                 jest.advanceTimersByTime(10000);
@@ -707,7 +994,7 @@ describe("MatrixRTCSession", () => {
 
                 mockRoom.getLiveTimeline().getState = jest
                     .fn()
-                    .mockReturnValue(makeMockRoomState([membershipTemplate, member2], mockRoom.roomId, undefined));
+                    .mockReturnValue(makeMockRoomState([membershipTemplate, member2], mockRoom.roomId));
                 sess.onMembershipUpdate();
 
                 await new Promise((resolve) => {
@@ -739,9 +1026,7 @@ describe("MatrixRTCSession", () => {
         const onMembershipsChanged = jest.fn();
         sess.on(MatrixRTCSessionEvent.MembershipsChanged, onMembershipsChanged);
 
-        mockRoom.getLiveTimeline().getState = jest
-            .fn()
-            .mockReturnValue(makeMockRoomState([], mockRoom.roomId, undefined));
+        mockRoom.getLiveTimeline().getState = jest.fn().mockReturnValue(makeMockRoomState([], mockRoom.roomId));
         sess.onMembershipUpdate();
 
         expect(onMembershipsChanged).toHaveBeenCalled();
@@ -751,7 +1036,7 @@ describe("MatrixRTCSession", () => {
         jest.useFakeTimers();
         try {
             const membership = Object.assign({}, membershipTemplate);
-            const mockRoom = makeMockRoom([membership], 0);
+            const mockRoom = makeMockRoom([membership]);
 
             sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
             const membershipObject = sess.memberships[0];
@@ -779,7 +1064,7 @@ describe("MatrixRTCSession", () => {
                     expires: 1000,
                 }),
             ];
-            const mockRoomNoExpired = makeMockRoom(mockMemberships, 0);
+            const mockRoomNoExpired = makeMockRoom(mockMemberships);
 
             sess = MatrixRTCSession.roomSessionForRoom(client, mockRoomNoExpired);
 
@@ -818,6 +1103,7 @@ describe("MatrixRTCSession", () => {
     it("fills in created_ts for other memberships on update", () => {
         client.sendStateEvent = jest.fn();
         jest.useFakeTimers();
+        jest.setSystemTime(1000);
         const mockRoom = makeMockRoom([
             Object.assign({}, membershipTemplate, {
                 device_id: "OTHERDEVICE",
@@ -875,6 +1161,7 @@ describe("MatrixRTCSession", () => {
                 ],
             }),
             getSender: jest.fn().mockReturnValue("@bob:example.org"),
+            getTs: jest.fn().mockReturnValue(Date.now()),
         } as unknown as MatrixEvent);
 
         const bobKeys = sess.getKeysForParticipant("@bob:example.org", "bobsphone")!;
@@ -898,6 +1185,7 @@ describe("MatrixRTCSession", () => {
                 ],
             }),
             getSender: jest.fn().mockReturnValue("@bob:example.org"),
+            getTs: jest.fn().mockReturnValue(Date.now()),
         } as unknown as MatrixEvent);
 
         const bobKeys = sess.getKeysForParticipant("@bob:example.org", "bobsphone")!;
@@ -909,6 +1197,130 @@ describe("MatrixRTCSession", () => {
         expect(bobKeys[4]).toEqual(Buffer.from("this is the key", "utf-8"));
     });
 
+    it("collects keys by merging", () => {
+        const mockRoom = makeMockRoom([membershipTemplate]);
+        sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
+        sess.onCallEncryption({
+            getType: jest.fn().mockReturnValue("io.element.call.encryption_keys"),
+            getContent: jest.fn().mockReturnValue({
+                device_id: "bobsphone",
+                call_id: "",
+                keys: [
+                    {
+                        index: 0,
+                        key: "dGhpcyBpcyB0aGUga2V5",
+                    },
+                ],
+            }),
+            getSender: jest.fn().mockReturnValue("@bob:example.org"),
+            getTs: jest.fn().mockReturnValue(Date.now()),
+        } as unknown as MatrixEvent);
+
+        let bobKeys = sess.getKeysForParticipant("@bob:example.org", "bobsphone")!;
+        expect(bobKeys).toHaveLength(1);
+        expect(bobKeys[0]).toEqual(Buffer.from("this is the key", "utf-8"));
+
+        sess.onCallEncryption({
+            getType: jest.fn().mockReturnValue("io.element.call.encryption_keys"),
+            getContent: jest.fn().mockReturnValue({
+                device_id: "bobsphone",
+                call_id: "",
+                keys: [
+                    {
+                        index: 4,
+                        key: "dGhpcyBpcyB0aGUga2V5",
+                    },
+                ],
+            }),
+            getSender: jest.fn().mockReturnValue("@bob:example.org"),
+            getTs: jest.fn().mockReturnValue(Date.now()),
+        } as unknown as MatrixEvent);
+
+        bobKeys = sess.getKeysForParticipant("@bob:example.org", "bobsphone")!;
+        expect(bobKeys).toHaveLength(5);
+        expect(bobKeys[4]).toEqual(Buffer.from("this is the key", "utf-8"));
+    });
+
+    it("ignores older keys at same index", () => {
+        const mockRoom = makeMockRoom([membershipTemplate]);
+        sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
+        sess.onCallEncryption({
+            getType: jest.fn().mockReturnValue("io.element.call.encryption_keys"),
+            getContent: jest.fn().mockReturnValue({
+                device_id: "bobsphone",
+                call_id: "",
+                keys: [
+                    {
+                        index: 0,
+                        key: encodeBase64(Buffer.from("newer key", "utf-8")),
+                    },
+                ],
+            }),
+            getSender: jest.fn().mockReturnValue("@bob:example.org"),
+            getTs: jest.fn().mockReturnValue(2000),
+        } as unknown as MatrixEvent);
+
+        sess.onCallEncryption({
+            getType: jest.fn().mockReturnValue("io.element.call.encryption_keys"),
+            getContent: jest.fn().mockReturnValue({
+                device_id: "bobsphone",
+                call_id: "",
+                keys: [
+                    {
+                        index: 0,
+                        key: encodeBase64(Buffer.from("older key", "utf-8")),
+                    },
+                ],
+            }),
+            getSender: jest.fn().mockReturnValue("@bob:example.org"),
+            getTs: jest.fn().mockReturnValue(1000), // earlier timestamp than the newer key
+        } as unknown as MatrixEvent);
+
+        const bobKeys = sess.getKeysForParticipant("@bob:example.org", "bobsphone")!;
+        expect(bobKeys).toHaveLength(1);
+        expect(bobKeys[0]).toEqual(Buffer.from("newer key", "utf-8"));
+    });
+
+    it("key timestamps are treated as monotonic", () => {
+        const mockRoom = makeMockRoom([membershipTemplate]);
+        sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
+        sess.onCallEncryption({
+            getType: jest.fn().mockReturnValue("io.element.call.encryption_keys"),
+            getContent: jest.fn().mockReturnValue({
+                device_id: "bobsphone",
+                call_id: "",
+                keys: [
+                    {
+                        index: 0,
+                        key: encodeBase64(Buffer.from("first key", "utf-8")),
+                    },
+                ],
+            }),
+            getSender: jest.fn().mockReturnValue("@bob:example.org"),
+            getTs: jest.fn().mockReturnValue(1000),
+        } as unknown as MatrixEvent);
+
+        sess.onCallEncryption({
+            getType: jest.fn().mockReturnValue("io.element.call.encryption_keys"),
+            getContent: jest.fn().mockReturnValue({
+                device_id: "bobsphone",
+                call_id: "",
+                keys: [
+                    {
+                        index: 0,
+                        key: encodeBase64(Buffer.from("second key", "utf-8")),
+                    },
+                ],
+            }),
+            getSender: jest.fn().mockReturnValue("@bob:example.org"),
+            getTs: jest.fn().mockReturnValue(1000), // same timestamp as the first key
+        } as unknown as MatrixEvent);
+
+        const bobKeys = sess.getKeysForParticipant("@bob:example.org", "bobsphone")!;
+        expect(bobKeys).toHaveLength(1);
+        expect(bobKeys[0]).toEqual(Buffer.from("second key", "utf-8"));
+    });
+
     it("ignores keys event for the local participant", () => {
         const mockRoom = makeMockRoom([membershipTemplate]);
         sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
@@ -925,6 +1337,7 @@ describe("MatrixRTCSession", () => {
                 ],
             }),
             getSender: jest.fn().mockReturnValue(client.getUserId()),
+            getTs: jest.fn().mockReturnValue(Date.now()),
         } as unknown as MatrixEvent);
 
         const myKeys = sess.getKeysForParticipant(client.getUserId()!, client.getDeviceId()!)!;

spec/unit/matrixrtc/MatrixRTCSessionManager.spec.ts

@@ -102,6 +102,7 @@ describe("MatrixRTCSessionManager", () => {
             getContent: jest.fn().mockReturnValue({}),
             getSender: jest.fn().mockReturnValue("@mock:user.example"),
             getRoomId: jest.fn().mockReturnValue("!room:id"),
+            isDecryptionFailure: jest.fn().mockReturnValue(false),
             sender: {
                 userId: "@mock:user.example",
             },
@@ -110,4 +111,93 @@ describe("MatrixRTCSessionManager", () => {
         await new Promise(process.nextTick);
         expect(onCallEncryptionMock).toHaveBeenCalled();
     });
+
+    describe("event decryption", () => {
+        it("Retries decryption and processes success", async () => {
+            try {
+                jest.useFakeTimers();
+                const room1 = makeMockRoom([membershipTemplate]);
+                jest.spyOn(client, "getRooms").mockReturnValue([room1]);
+                jest.spyOn(client, "getRoom").mockReturnValue(room1);
+
+                client.emit(ClientEvent.Room, room1);
+                const onCallEncryptionMock = jest.fn();
+                client.matrixRTC.getRoomSession(room1).onCallEncryption = onCallEncryptionMock;
+                let isDecryptionFailure = true;
+                client.decryptEventIfNeeded = jest
+                    .fn()
+                    .mockReturnValueOnce(Promise.resolve())
+                    .mockImplementation(() => {
+                        isDecryptionFailure = false;
+                        return Promise.resolve();
+                    });
+                const timelineEvent = {
+                    getType: jest.fn().mockReturnValue(EventType.CallEncryptionKeysPrefix),
+                    getContent: jest.fn().mockReturnValue({}),
+                    getSender: jest.fn().mockReturnValue("@mock:user.example"),
+                    getRoomId: jest.fn().mockReturnValue("!room:id"),
+                    isDecryptionFailure: jest.fn().mockImplementation(() => isDecryptionFailure),
+                    getId: jest.fn().mockReturnValue("event_id"),
+                    sender: {
+                        userId: "@mock:user.example",
+                    },
+                } as unknown as MatrixEvent;
+                client.emit(RoomEvent.Timeline, timelineEvent, undefined, undefined, false, {} as IRoomTimelineData);
+
+                expect(client.decryptEventIfNeeded).toHaveBeenCalledTimes(1);
+                expect(onCallEncryptionMock).toHaveBeenCalledTimes(0);
+
+                // should retry after one second:
+                await jest.advanceTimersByTimeAsync(1500);
+
+                expect(client.decryptEventIfNeeded).toHaveBeenCalledTimes(2);
+                expect(onCallEncryptionMock).toHaveBeenCalledTimes(1);
+            } finally {
+                jest.useRealTimers();
+            }
+        });
+
+        it("Retries decryption and processes failure", async () => {
+            try {
+                jest.useFakeTimers();
+                const room1 = makeMockRoom([membershipTemplate]);
+                jest.spyOn(client, "getRooms").mockReturnValue([room1]);
+                jest.spyOn(client, "getRoom").mockReturnValue(room1);
+
+                client.emit(ClientEvent.Room, room1);
+                const onCallEncryptionMock = jest.fn();
+                client.matrixRTC.getRoomSession(room1).onCallEncryption = onCallEncryptionMock;
+                client.decryptEventIfNeeded = jest.fn().mockReturnValue(Promise.resolve());
+                const timelineEvent = {
+                    getType: jest.fn().mockReturnValue(EventType.CallEncryptionKeysPrefix),
+                    getContent: jest.fn().mockReturnValue({}),
+                    getSender: jest.fn().mockReturnValue("@mock:user.example"),
+                    getRoomId: jest.fn().mockReturnValue("!room:id"),
+                    isDecryptionFailure: jest.fn().mockReturnValue(true), // always fail
+                    getId: jest.fn().mockReturnValue("event_id"),
+                    sender: {
+                        userId: "@mock:user.example",
+                    },
+                } as unknown as MatrixEvent;
+                client.emit(RoomEvent.Timeline, timelineEvent, undefined, undefined, false, {} as IRoomTimelineData);
+
+                expect(client.decryptEventIfNeeded).toHaveBeenCalledTimes(1);
+                expect(onCallEncryptionMock).toHaveBeenCalledTimes(0);
+
+                // should retry after one second:
+                await jest.advanceTimersByTimeAsync(1500);
+
+                expect(client.decryptEventIfNeeded).toHaveBeenCalledTimes(2);
+                expect(onCallEncryptionMock).toHaveBeenCalledTimes(0);
+
+                // doesn't retry again:
+                await jest.advanceTimersByTimeAsync(1500);
+
+                expect(client.decryptEventIfNeeded).toHaveBeenCalledTimes(2);
+                expect(onCallEncryptionMock).toHaveBeenCalledTimes(0);
+            } finally {
+                jest.useRealTimers();
+            }
+        });
+    });
 });

spec/unit/matrixrtc/mocks.ts

@@ -20,10 +20,10 @@ import { randomString } from "../../../src/randomstring";
 
 type MembershipData = CallMembershipData[] | SessionMembershipData;
 
-export function makeMockRoom(membershipData: MembershipData, localAge: number | null = null): Room {
+export function makeMockRoom(membershipData: MembershipData): Room {
     const roomId = randomString(8);
     // Caching roomState here so it does not get recreated when calling `getLiveTimeline.getState()`
-    const roomState = makeMockRoomState(membershipData, roomId, localAge);
+    const roomState = makeMockRoomState(membershipData, roomId);
     return {
         roomId: roomId,
         hasMembershipState: jest.fn().mockReturnValue(true),
@@ -34,8 +34,8 @@ export function makeMockRoom(membershipData: MembershipData, localAge: number |
     } as unknown as Room;
 }
 
-export function makeMockRoomState(membershipData: MembershipData, roomId: string, localAge: number | null = null) {
-    const event = mockRTCEvent(membershipData, roomId, localAge);
+export function makeMockRoomState(membershipData: MembershipData, roomId: string) {
+    const event = mockRTCEvent(membershipData, roomId);
     return {
         on: jest.fn(),
         off: jest.fn(),
@@ -57,7 +57,7 @@ export function makeMockRoomState(membershipData: MembershipData, roomId: string
     };
 }
 
-export function mockRTCEvent(membershipData: MembershipData, roomId: string, localAge: number | null): MatrixEvent {
+export function mockRTCEvent(membershipData: MembershipData, roomId: string): MatrixEvent {
     return {
         getType: jest.fn().mockReturnValue(EventType.GroupCallMemberPrefix),
         getContent: jest.fn().mockReturnValue(
@@ -68,11 +68,11 @@ export function mockRTCEvent(membershipData: MembershipData, roomId: string, loc
                   },
         ),
         getSender: jest.fn().mockReturnValue("@mock:user.example"),
-        getTs: jest.fn().mockReturnValue(1000),
-        localTimestamp: Date.now() - (localAge ?? 10),
+        getTs: jest.fn().mockReturnValue(Date.now()),
         getRoomId: jest.fn().mockReturnValue(roomId),
         sender: {
             userId: "@mock:user.example",
         },
+        isDecryptionFailure: jest.fn().mockReturnValue(false),
     } as unknown as MatrixEvent;
 }

spec/unit/models/event.spec.ts

@@ -412,7 +412,12 @@ describe("MatrixEvent", () => {
             const crypto = {
                 decryptEvent: jest
                     .fn()
-                    .mockRejectedValue("DecryptionError: The sender has disabled encrypting to unverified devices."),
+                    .mockRejectedValue(
+                        new DecryptionError(
+                            DecryptionFailureCode.MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE,
+                            "The sender has disabled encrypting to unverified devices.",
+                        ),
+                    ),
             } as unknown as Crypto;
 
             await encryptedEvent.attemptDecryption(crypto);

spec/unit/oidc/authorize.spec.ts

@@ -89,11 +89,8 @@ describe("oidc authorization", () => {
 
     describe("generateAuthorizationUrl()", () => {
         it("should generate url with correct parameters", async () => {
-            // test the no crypto case here
-            // @ts-ignore mocking
-            globalThis.crypto.subtle = undefined;
-
             const authorizationParams = generateAuthorizationParams({ redirectUri: baseUrl });
+            authorizationParams.codeVerifier = "test-code-verifier";
             const authUrl = new URL(
                 await generateAuthorizationUrl(authorizationEndpoint, clientId, authorizationParams),
             );
@@ -105,6 +102,18 @@ describe("oidc authorization", () => {
             expect(authUrl.searchParams.get("scope")).toEqual(authorizationParams.scope);
             expect(authUrl.searchParams.get("state")).toEqual(authorizationParams.state);
             expect(authUrl.searchParams.get("nonce")).toEqual(authorizationParams.nonce);
+            expect(authUrl.searchParams.get("code_challenge")).toEqual("0FLIKahrX7kqxncwhV5WD82lu_wi5GA8FsRSLubaOpU");
+        });
+
+        it("should log a warning if crypto is not available", async () => {
+            // test the no crypto case here
+            // @ts-ignore mocking
+            globalThis.crypto.subtle = undefined;
+
+            const authorizationParams = generateAuthorizationParams({ redirectUri: baseUrl });
+            const authUrl = new URL(
+                await generateAuthorizationUrl(authorizationEndpoint, clientId, authorizationParams),
+            );
 
             // crypto not available, plain text code_challenge is used
             expect(authUrl.searchParams.get("code_challenge")).toEqual(authorizationParams.codeVerifier);

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

@@ -95,6 +95,7 @@ describe("initRustCrypto", () => {
             deleteSecretsFromInbox: jest.fn(),
             registerReceiveSecretCallback: jest.fn(),
             registerDevicesUpdatedCallback: jest.fn(),
+            registerRoomKeysWithheldCallback: jest.fn(),
             outgoingRequests: jest.fn(),
             isBackupEnabled: jest.fn().mockResolvedValue(false),
             verifyBackup: jest.fn().mockResolvedValue({ trusted: jest.fn().mockReturnValue(false) }),

spec/unit/timeline-window.spec.ts

@@ -434,7 +434,7 @@ describe("TimelineWindow", function () {
     });
 
     function idsOf(events: Array<MatrixEvent>): Array<string> {
-        return events.map((e) => (e ? e.getId() ?? "MISSING_ID" : "MISSING_EVENT"));
+        return events.map((e) => (e ? (e.getId() ?? "MISSING_ID") : "MISSING_EVENT"));
     }
 
     describe("removing events", () => {

spec/unit/webrtc/groupCall.spec.ts

@@ -105,7 +105,7 @@ const mockGetStateEvents =
     (events: MatrixEvent[] = FAKE_STATE_EVENTS as MatrixEvent[]) =>
     (type: EventType, userId?: string): MatrixEvent[] | MatrixEvent | null => {
         if (type === EventType.GroupCallMemberPrefix) {
-            return userId === undefined ? events : events.find((e) => e.getStateKey() === userId) ?? null;
+            return userId === undefined ? events : (events.find((e) => e.getStateKey() === userId) ?? null);
         } else {
             const fakeEvent = { getContent: () => ({}), getTs: () => 0 } as MatrixEvent;
             return userId === undefined ? [fakeEvent] : fakeEvent;

src/@types/global.d.ts

@@ -29,20 +29,11 @@ declare global {
 
     namespace NodeJS {
         interface Global {
-            localStorage: Storage;
             // marker variable used to detect both the browser & node entrypoints being used at once
             __js_sdk_entrypoint: unknown;
         }
     }
 
-    interface Window {
-        webkitAudioContext: typeof AudioContext;
-    }
-
-    interface Crypto {
-        webkitSubtle?: Window["crypto"]["subtle"];
-    }
-
     interface MediaDevices {
         // This is experimental and types don't know about it yet
         // https://github.com/microsoft/TypeScript/issues/33232
@@ -76,40 +67,4 @@ declare global {
         // on webkit: we should check if we still need to do this
         webkitGetUserMedia: DummyInterfaceWeShouldntBeUsingThis;
     }
-
-    export interface ISettledFulfilled<T> {
-        status: "fulfilled";
-        value: T;
-    }
-    export interface ISettledRejected {
-        status: "rejected";
-        reason: any;
-    }
-
-    interface PromiseConstructor {
-        allSettled<T>(promises: Promise<T>[]): Promise<Array<ISettledFulfilled<T> | ISettledRejected>>;
-    }
-
-    interface RTCRtpTransceiver {
-        // This has been removed from TS
-        // (https://github.com/microsoft/TypeScript-DOM-lib-generator/issues/1029),
-        // but we still need this for MatrixCall::getRidOfRTXCodecs()
-        setCodecPreferences(codecs: RTCRtpCodecCapability[]): void;
-    }
-
-    interface RequestInit {
-        /**
-         * Specifies the priority of the fetch request relative to other requests of the same type.
-         * Must be one of the following strings:
-         *   high: A high priority fetch request relative to other requests of the same type.
-         *   low: A low priority fetch request relative to other requests of the same type.
-         *   auto: Automatically determine the priority of the fetch request relative to other requests of the same type (default).
-         *
-         * @see https://html.spec.whatwg.org/multipage/urls-and-fetching.html#fetch-priority-attribute
-         * @see https://github.com/microsoft/TypeScript/issues/54472
-         * @see https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API#browser_compatibility
-         * Not yet supported in Safari or Firefox
-         */
-        priority?: "high" | "low" | "auto";
-    }
 }

src/@types/requests.ts

@@ -76,6 +76,56 @@ export interface ISendEventResponse {
     event_id: string;
 }
 
+export type TimeoutDelay = {
+    delay: number;
+};
+
+export type ParentDelayId = {
+    parent_delay_id: string;
+};
+
+export type SendTimeoutDelayedEventRequestOpts = TimeoutDelay & Partial<ParentDelayId>;
+export type SendActionDelayedEventRequestOpts = ParentDelayId;
+
+export type SendDelayedEventRequestOpts = SendTimeoutDelayedEventRequestOpts | SendActionDelayedEventRequestOpts;
+
+export type SendDelayedEventResponse = {
+    delay_id: string;
+};
+
+export enum UpdateDelayedEventAction {
+    Cancel = "cancel",
+    Restart = "restart",
+    Send = "send",
+}
+
+export type UpdateDelayedEventRequestOpts = SendDelayedEventResponse & {
+    action: UpdateDelayedEventAction;
+};
+
+type DelayedPartialTimelineEvent = {
+    room_id: string;
+    type: string;
+    content: IContent;
+};
+
+type DelayedPartialStateEvent = DelayedPartialTimelineEvent & {
+    state_key: string;
+    transaction_id: string;
+};
+
+type DelayedPartialEvent = DelayedPartialTimelineEvent | DelayedPartialStateEvent;
+
+export type DelayedEventInfo = {
+    delayed_events: DelayedPartialEvent &
+        SendDelayedEventResponse &
+        SendDelayedEventRequestOpts &
+        {
+            running_since: number;
+        }[];
+    next_batch?: string;
+};
+
 export interface IPresenceOpts {
     // One of "online", "offline" or "unavailable"
     presence: "online" | "offline" | "unavailable";

src/client.ts

@@ -47,7 +47,7 @@ import { Direction, EventTimeline } from "./models/event-timeline";
 import { IActionsObject, PushProcessor } from "./pushprocessor";
 import { AutoDiscovery, AutoDiscoveryAction } from "./autodiscovery";
 import * as olmlib from "./crypto/olmlib";
-import { decodeBase64, encodeBase64 } from "./base64";
+import { decodeBase64, encodeBase64, encodeUnpaddedBase64Url } from "./base64";
 import { IExportedDevice as IExportedOlmDevice } from "./crypto/OlmDevice";
 import { IOlmDevice } from "./crypto/algorithms/megolm";
 import { TypedReEmitter } from "./ReEmitter";
@@ -114,6 +114,7 @@ import { NotificationCountType, Room, RoomEvent, RoomEventHandlerMap, RoomNameSt
 import { RoomMemberEvent, RoomMemberEventHandlerMap } from "./models/room-member";
 import { IPowerLevelsContent, RoomStateEvent, RoomStateEventHandlerMap } from "./models/room-state";
 import {
+    DelayedEventInfo,
     IAddThreePidOnlyBody,
     IBindThreePidBody,
     IContextResponse,
@@ -134,6 +135,9 @@ import {
     IStatusResponse,
     ITagsResponse,
     KnockRoomOpts,
+    SendDelayedEventRequestOpts,
+    SendDelayedEventResponse,
+    UpdateDelayedEventAction,
 } from "./@types/requests";
 import {
     EventType,
@@ -227,6 +231,7 @@ import { KnownMembership, Membership } from "./@types/membership";
 import { RoomMessageEventContent, StickerEventContent } from "./@types/events";
 import { ImageInfo } from "./@types/media";
 import { Capabilities, ServerCapabilities } from "./serverCapabilities";
+import { sha256 } from "./digest";
 
 export type Store = IStore;
 
@@ -324,10 +329,13 @@ export interface ICreateClientOpts {
     localTimeoutMs?: number;
 
     /**
-     * Set to true to use
-     * Authorization header instead of query param to send the access token to the server.
+     * Set to false to send the access token to the server via a query parameter rather
+     * than the Authorization HTTP header.
      *
-     * Default false.
+     * Note that as of v1.11 of the Matrix spec, sending the access token via a query
+     * is deprecated.
+     *
+     * Default true.
      */
     useAuthorizationHeader?: boolean;
 
@@ -527,6 +535,8 @@ export const UNSTABLE_MSC2666_SHARED_ROOMS = "uk.half-shot.msc2666";
 export const UNSTABLE_MSC2666_MUTUAL_ROOMS = "uk.half-shot.msc2666.mutual_rooms";
 export const UNSTABLE_MSC2666_QUERY_MUTUAL_ROOMS = "uk.half-shot.msc2666.query_mutual_rooms";
 
+export const UNSTABLE_MSC4140_DELAYED_EVENTS = "org.matrix.msc4140";
+
 enum CrossSigningKeyType {
     MasterKey = "master_key",
     SelfSigningKey = "self_signing_key",
@@ -4570,12 +4580,19 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             threadId = threadIdOrEventType;
         }
 
-        // If we expect that an event is part of a thread but is missing the relation
-        // we need to add it manually, as well as the reply fallback
-        if (threadId && !content!["m.relates_to"]?.rel_type) {
-            const isReply = !!content!["m.relates_to"]?.["m.in_reply_to"];
-            content!["m.relates_to"] = {
-                ...content!["m.relates_to"],
+        this.addThreadRelationIfNeeded(content, threadId, roomId);
+        return this.sendCompleteEvent(roomId, threadId, { type: eventType, content }, txnId);
+    }
+
+    /**
+     * If we expect that an event is part of a thread but is missing the relation
+     * we need to add it manually, as well as the reply fallback
+     */
+    private addThreadRelationIfNeeded(content: IContent, threadId: string | null, roomId: string): void {
+        if (threadId && !content["m.relates_to"]?.rel_type) {
+            const isReply = !!content["m.relates_to"]?.["m.in_reply_to"];
+            content["m.relates_to"] = {
+                ...content["m.relates_to"],
                 rel_type: THREAD_RELATION_TYPE.name,
                 event_id: threadId,
                 // Set is_falling_back to true unless this is actually intended to be a reply
@@ -4583,7 +4600,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             };
             const thread = this.getRoom(roomId)?.getThread(threadId);
             if (thread && !isReply) {
-                content!["m.relates_to"]["m.in_reply_to"] = {
+                content["m.relates_to"]["m.in_reply_to"] = {
                     event_id:
                         thread
                             .lastReply((ev: MatrixEvent) => {
@@ -4593,8 +4610,6 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                 };
             }
         }
-
-        return this.sendCompleteEvent(roomId, threadId, { type: eventType, content }, txnId);
     }
 
     /**
@@ -4608,7 +4623,38 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         threadId: string | null,
         eventObject: Partial<IEvent>,
         txnId?: string,
-    ): Promise<ISendEventResponse> {
+    ): Promise<ISendEventResponse>;
+    /**
+     * Sends a delayed event (MSC4140).
+     * @param eventObject - An object with the partial structure of an event, to which event_id, user_id, room_id and origin_server_ts will be added.
+     * @param delayOpts - Properties of the delay for this event.
+     * @param txnId - Optional.
+     * @returns Promise which resolves: to an empty object `{}`
+     * @returns Rejects: with an error response.
+     */
+    private sendCompleteEvent(
+        roomId: string,
+        threadId: string | null,
+        eventObject: Partial<IEvent>,
+        delayOpts: SendDelayedEventRequestOpts,
+        txnId?: string,
+    ): Promise<SendDelayedEventResponse>;
+    private sendCompleteEvent(
+        roomId: string,
+        threadId: string | null,
+        eventObject: Partial<IEvent>,
+        delayOptsOrTxnId?: SendDelayedEventRequestOpts | string,
+        txnIdOrVoid?: string,
+    ): Promise<ISendEventResponse | SendDelayedEventResponse> {
+        let delayOpts: SendDelayedEventRequestOpts | undefined;
+        let txnId: string | undefined;
+        if (typeof delayOptsOrTxnId === "string") {
+            txnId = delayOptsOrTxnId;
+        } else {
+            delayOpts = delayOptsOrTxnId;
+            txnId = txnIdOrVoid;
+        }
+
         if (!txnId) {
             txnId = this.makeTxnId();
         }
@@ -4631,9 +4677,11 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             localEvent.setThread(thread);
         }
 
-        // set up re-emitter for this new event - this is normally the job of EventMapper but we don't use it here
-        this.reEmitter.reEmit(localEvent, [MatrixEventEvent.Replaced, MatrixEventEvent.VisibilityChange]);
-        room?.reEmitter.reEmit(localEvent, [MatrixEventEvent.BeforeRedaction]);
+        if (!delayOpts) {
+            // set up re-emitter for this new event - this is normally the job of EventMapper but we don't use it here
+            this.reEmitter.reEmit(localEvent, [MatrixEventEvent.Replaced, MatrixEventEvent.VisibilityChange]);
+            room?.reEmitter.reEmit(localEvent, [MatrixEventEvent.BeforeRedaction]);
+        }
 
         // if this is a relation or redaction of an event
         // that hasn't been sent yet (e.g. with a local id starting with a ~)
@@ -4648,29 +4696,56 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         }
 
         const type = localEvent.getType();
-        this.logger.debug(`sendEvent of type ${type} in ${roomId} with txnId ${txnId}`);
+        this.logger.debug(
+            `sendEvent of type ${type} in ${roomId} with txnId ${txnId}${delayOpts ? " (delayed event)" : ""}`,
+        );
 
         localEvent.setTxnId(txnId);
         localEvent.setStatus(EventStatus.SENDING);
 
-        // add this event immediately to the local store as 'sending'.
-        room?.addPendingEvent(localEvent, txnId);
+        // TODO: separate store for delayed events?
+        if (!delayOpts) {
+            // add this event immediately to the local store as 'sending'.
+            room?.addPendingEvent(localEvent, txnId);
 
-        // addPendingEvent can change the state to NOT_SENT if it believes
-        // that there's other events that have failed. We won't bother to
-        // try sending the event if the state has changed as such.
-        if (localEvent.status === EventStatus.NOT_SENT) {
-            return Promise.reject(new Error("Event blocked by other events not yet sent"));
+            // addPendingEvent can change the state to NOT_SENT if it believes
+            // that there's other events that have failed. We won't bother to
+            // try sending the event if the state has changed as such.
+            if (localEvent.status === EventStatus.NOT_SENT) {
+                return Promise.reject(new Error("Event blocked by other events not yet sent"));
+            }
+
+            return this.encryptAndSendEvent(room, localEvent);
+        } else {
+            return this.encryptAndSendEvent(room, localEvent, delayOpts);
         }
-
-        return this.encryptAndSendEvent(room, localEvent);
     }
 
     /**
      * encrypts the event if necessary; adds the event to the queue, or sends it; marks the event as sent/unsent
      * @returns returns a promise which resolves with the result of the send request
      */
-    protected async encryptAndSendEvent(room: Room | null, event: MatrixEvent): Promise<ISendEventResponse> {
+    protected async encryptAndSendEvent(room: Room | null, event: MatrixEvent): Promise<ISendEventResponse>;
+    /**
+     * Simply sends a delayed event without encrypting it.
+     * TODO: Allow encrypted delayed events, and encrypt them properly
+     * @param delayOpts - Properties of the delay for this event.
+     * @returns returns a promise which resolves with the result of the delayed send request
+     */
+    protected async encryptAndSendEvent(
+        room: Room | null,
+        event: MatrixEvent,
+        delayOpts: SendDelayedEventRequestOpts,
+    ): Promise<SendDelayedEventResponse>;
+    protected async encryptAndSendEvent(
+        room: Room | null,
+        event: MatrixEvent,
+        delayOpts?: SendDelayedEventRequestOpts,
+    ): Promise<ISendEventResponse | SendDelayedEventResponse> {
+        if (delayOpts) {
+            return this.sendEventHttpRequest(event, delayOpts);
+        }
+
         try {
             let cancelled: boolean;
             this.eventsBeingEncrypted.add(event.getId()!);
@@ -4821,7 +4896,15 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         }
     }
 
-    private sendEventHttpRequest(event: MatrixEvent): Promise<ISendEventResponse> {
+    private sendEventHttpRequest(event: MatrixEvent): Promise<ISendEventResponse>;
+    private sendEventHttpRequest(
+        event: MatrixEvent,
+        delayOpts: SendDelayedEventRequestOpts,
+    ): Promise<SendDelayedEventResponse>;
+    private sendEventHttpRequest(
+        event: MatrixEvent,
+        delayOpts?: SendDelayedEventRequestOpts,
+    ): Promise<ISendEventResponse | SendDelayedEventResponse> {
         let txnId = event.getTxnId();
         if (!txnId) {
             txnId = this.makeTxnId();
@@ -4853,12 +4936,20 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             path = utils.encodeUri("/rooms/$roomId/send/$eventType/$txnId", pathParams);
         }
 
-        return this.http
-            .authedRequest<ISendEventResponse>(Method.Put, path, undefined, event.getWireContent())
-            .then((res) => {
+        const content = event.getWireContent();
+        if (!delayOpts) {
+            return this.http.authedRequest<ISendEventResponse>(Method.Put, path, undefined, content).then((res) => {
                 this.logger.debug(`Event sent to ${event.getRoomId()} with event id ${res.event_id}`);
                 return res;
             });
+        } else {
+            return this.http.authedRequest<SendDelayedEventResponse>(
+                Method.Put,
+                path,
+                getUnstableDelayQueryOpts(delayOpts),
+                content,
+            );
+        }
     }
 
     /**
@@ -5188,6 +5279,101 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         return this.sendMessage(roomId, threadId, content);
     }
 
+    /**
+     * Send a delayed timeline event.
+     *
+     * Note: This endpoint is unstable, and can throw an `Error`.
+     *   Check progress on [MSC4140](https://github.com/matrix-org/matrix-spec-proposals/pull/4140) for more details.
+     */
+    // eslint-disable-next-line
+    public async _unstable_sendDelayedEvent<K extends keyof TimelineEvents>(
+        roomId: string,
+        delayOpts: SendDelayedEventRequestOpts,
+        threadId: string | null,
+        eventType: K,
+        content: TimelineEvents[K],
+        txnId?: string,
+    ): Promise<SendDelayedEventResponse> {
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
+            throw Error("Server does not support the delayed events API");
+        }
+
+        this.addThreadRelationIfNeeded(content, threadId, roomId);
+        return this.sendCompleteEvent(roomId, threadId, { type: eventType, content }, delayOpts, txnId);
+    }
+
+    /**
+     * Send a delayed state event.
+     *
+     * Note: This endpoint is unstable, and can throw an `Error`.
+     *   Check progress on [MSC4140](https://github.com/matrix-org/matrix-spec-proposals/pull/4140) for more details.
+     */
+    // eslint-disable-next-line
+    public async _unstable_sendDelayedStateEvent<K extends keyof StateEvents>(
+        roomId: string,
+        delayOpts: SendDelayedEventRequestOpts,
+        eventType: K,
+        content: StateEvents[K],
+        stateKey = "",
+        opts: IRequestOpts = {},
+    ): Promise<SendDelayedEventResponse> {
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
+            throw Error("Server does not support the delayed events API");
+        }
+
+        const pathParams = {
+            $roomId: roomId,
+            $eventType: eventType,
+            $stateKey: stateKey,
+        };
+        let path = utils.encodeUri("/rooms/$roomId/state/$eventType", pathParams);
+        if (stateKey !== undefined) {
+            path = utils.encodeUri(path + "/$stateKey", pathParams);
+        }
+        return this.http.authedRequest(Method.Put, path, getUnstableDelayQueryOpts(delayOpts), content as Body, opts);
+    }
+
+    /**
+     * Get all pending delayed events for the calling user.
+     *
+     * Note: This endpoint is unstable, and can throw an `Error`.
+     *   Check progress on [MSC4140](https://github.com/matrix-org/matrix-spec-proposals/pull/4140) for more details.
+     */
+    // eslint-disable-next-line
+    public async _unstable_getDelayedEvents(fromToken?: string): Promise<DelayedEventInfo> {
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
+            throw Error("Server does not support the delayed events API");
+        }
+
+        const queryDict = fromToken ? { from: fromToken } : undefined;
+        return await this.http.authedRequest(Method.Get, "/delayed_events", queryDict, undefined, {
+            prefix: `${ClientPrefix.Unstable}/${UNSTABLE_MSC4140_DELAYED_EVENTS}`,
+        });
+    }
+
+    /**
+     * Manage a delayed event associated with the given delay_id.
+     *
+     * Note: This endpoint is unstable, and can throw an `Error`.
+     *   Check progress on [MSC4140](https://github.com/matrix-org/matrix-spec-proposals/pull/4140) for more details.
+     */
+    // eslint-disable-next-line
+    public async _unstable_updateDelayedEvent(delayId: string, action: UpdateDelayedEventAction): Promise<{}> {
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
+            throw Error("Server does not support the delayed events API");
+        }
+
+        const path = utils.encodeUri("/delayed_events/$delayId", {
+            $delayId: delayId,
+        });
+        const data = {
+            action,
+        };
+        return await this.http.authedRequest(Method.Post, path, undefined, data, {
+            prefix: `${ClientPrefix.Unstable}/${UNSTABLE_MSC4140_DELAYED_EVENTS}`,
+        });
+    }
+
     /**
      * Send a receipt.
      * @param event - The event being acknowledged
@@ -5401,10 +5587,15 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
     private findPredecessorRooms(room: Room, verifyLinks: boolean, msc3946ProcessDynamicPredecessor: boolean): Room[] {
         const ret: Room[] = [];
+        const seenRoomIDs = new Set<string>([room.roomId]);
 
         // Work backwards from newer to older rooms
         let predecessorRoomId = room.findPredecessor(msc3946ProcessDynamicPredecessor)?.roomId;
         while (predecessorRoomId !== null) {
+            if (predecessorRoomId) {
+                if (seenRoomIDs.has(predecessorRoomId)) break;
+                seenRoomIDs.add(predecessorRoomId);
+            }
             const predecessorRoom = this.getRoom(predecessorRoomId);
             if (predecessorRoom === null) {
                 break;
@@ -9299,20 +9490,19 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
         // When picking an algorithm, we pick the hashed over no hashes
         if (hashes["algorithms"].includes("sha256")) {
-            // Abuse the olm hashing
-            const olmutil = new global.Olm.Utility();
-            params["addresses"] = addressPairs.map((p) => {
-                const addr = p[0].toLowerCase(); // lowercase to get consistent hashes
-                const med = p[1].toLowerCase();
-                const hashed = olmutil
-                    .sha256(`${addr} ${med} ${params["pepper"]}`)
-                    .replace(/\+/g, "-")
-                    .replace(/\//g, "_"); // URL-safe base64
-                // Map the hash to a known (case-sensitive) address. We use the case
-                // sensitive version because the caller might be expecting that.
-                localMapping[hashed] = p[0];
-                return hashed;
-            });
+            params["addresses"] = await Promise.all(
+                addressPairs.map(async (p) => {
+                    const addr = p[0].toLowerCase(); // lowercase to get consistent hashes
+                    const med = p[1].toLowerCase();
+                    const hashBuffer = await sha256(`${addr} ${med} ${params["pepper"]}`);
+                    const hashed = encodeUnpaddedBase64Url(hashBuffer);
+
+                    // Map the hash to a known (case-sensitive) address. We use the case
+                    // sensitive version because the caller might be expecting that.
+                    localMapping[hashed] = p[0];
+                    return hashed;
+                }),
+            );
             params["algorithm"] = "sha256";
         } else if (hashes["algorithms"].includes("none")) {
             params["addresses"] = addressPairs.map((p) => {
@@ -9889,6 +10079,12 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     }
 }
 
+function getUnstableDelayQueryOpts(delayOpts: SendDelayedEventRequestOpts): QueryDict {
+    return Object.fromEntries(
+        Object.entries(delayOpts).map(([k, v]) => [`${UNSTABLE_MSC4140_DELAYED_EVENTS}.${k}`, v]),
+    );
+}
+
 /**
  * recalculates an accurate notifications count on event decryption.
  * Servers do not have enough knowledge about encrypted events to calculate an

src/crypto-api/index.ts

@@ -557,6 +557,12 @@ export enum DecryptionFailureCode {
     /** Message was encrypted with a Megolm session whose keys have not been shared with us. */
     MEGOLM_UNKNOWN_INBOUND_SESSION_ID = "MEGOLM_UNKNOWN_INBOUND_SESSION_ID",
 
+    /** A special case of {@link MEGOLM_UNKNOWN_INBOUND_SESSION_ID}: the sender has told us it is withholding the key. */
+    MEGOLM_KEY_WITHHELD = "MEGOLM_KEY_WITHHELD",
+
+    /** A special case of {@link MEGOLM_KEY_WITHHELD}: the sender has told us it is withholding the key, because the current device is unverified. */
+    MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE = "MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE",
+
     /** Message was encrypted with a Megolm session which has been shared with us, but in a later ratchet state. */
     OLM_UNKNOWN_MESSAGE_INDEX = "OLM_UNKNOWN_MESSAGE_INDEX",
 
@@ -848,9 +854,14 @@ export interface CreateSecretStorageOpts {
     setupNewSecretStorage?: boolean;
 
     /**
-     * Function called to get the user's
-     * current key backup passphrase. Should return a promise that resolves with a Uint8Array
+     * Function called to get the user's current key backup passphrase.
+     *
+     * Should return a promise that resolves with a Uint8Array
      * containing the key, or rejects if the key cannot be obtained.
+     *
+     * Only used when the client has existing key backup, but no secret storage.
+     *
+     * @deprecated Not used by the Rust crypto stack.
      */
     getKeyBackupPassphrase?: () => Promise<Uint8Array>;
 }

src/crypto/OlmDevice.ts

@@ -1221,13 +1221,13 @@ export class OlmDevice {
                 this.getInboundGroupSession(roomId, senderKey, sessionId, txn, (session, sessionData, withheld) => {
                     if (session === null || sessionData === null) {
                         if (withheld) {
-                            error = new DecryptionError(
-                                DecryptionFailureCode.MEGOLM_UNKNOWN_INBOUND_SESSION_ID,
-                                calculateWithheldMessage(withheld),
-                                {
-                                    session: senderKey + "|" + sessionId,
-                                },
-                            );
+                            const failureCode =
+                                withheld.code === "m.unverified"
+                                    ? DecryptionFailureCode.MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE
+                                    : DecryptionFailureCode.MEGOLM_KEY_WITHHELD;
+                            error = new DecryptionError(failureCode, calculateWithheldMessage(withheld), {
+                                session: senderKey + "|" + sessionId,
+                            });
                         }
                         result = null;
                         return;
@@ -1237,13 +1237,13 @@ export class OlmDevice {
                         res = session.decrypt(body);
                     } catch (e) {
                         if ((<Error>e)?.message === "OLM.UNKNOWN_MESSAGE_INDEX" && withheld) {
-                            error = new DecryptionError(
-                                DecryptionFailureCode.MEGOLM_UNKNOWN_INBOUND_SESSION_ID,
-                                calculateWithheldMessage(withheld),
-                                {
-                                    session: senderKey + "|" + sessionId,
-                                },
-                            );
+                            const failureCode =
+                                withheld.code === "m.unverified"
+                                    ? DecryptionFailureCode.MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE
+                                    : DecryptionFailureCode.MEGOLM_KEY_WITHHELD;
+                            error = new DecryptionError(failureCode, calculateWithheldMessage(withheld), {
+                                session: senderKey + "|" + sessionId,
+                            });
                         } else {
                             error = <Error>e;
                         }

src/crypto/algorithms/base.ts

@@ -66,7 +66,6 @@ export abstract class EncryptionAlgorithm {
     protected readonly crypto: Crypto;
     protected readonly olmDevice: OlmDevice;
     protected readonly baseApis: MatrixClient;
-    protected readonly roomId?: string;
 
     /**
      * @param params - parameters
@@ -77,7 +76,6 @@ export abstract class EncryptionAlgorithm {
         this.crypto = params.crypto;
         this.olmDevice = params.olmDevice;
         this.baseApis = params.baseApis;
-        this.roomId = params.roomId;
     }
 
     /**
@@ -127,14 +125,12 @@ export abstract class DecryptionAlgorithm {
     protected readonly crypto: Crypto;
     protected readonly olmDevice: OlmDevice;
     protected readonly baseApis: MatrixClient;
-    protected readonly roomId?: string;
 
     public constructor(params: DecryptionClassParams) {
         this.userId = params.userId;
         this.crypto = params.crypto;
         this.olmDevice = params.olmDevice;
         this.baseApis = params.baseApis;
-        this.roomId = params.roomId;
     }
 
     /**

src/digest.ts

@@ -0,0 +1,34 @@
+/*
+Copyright 2024 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+/**
+ * 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
+ * @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> {
+    if (!globalThis.crypto.subtle) {
+        throw new Error("Crypto.subtle is not available: insecure context?");
+    }
+    const utf8 = new TextEncoder().encode(plaintext);
+
+    const digest = await globalThis.crypto.subtle.digest("SHA-256", utf8);
+
+    return digest;
+}

src/embedded.ts

@@ -26,8 +26,13 @@ import {
 } from "matrix-widget-api";
 
 import { MatrixEvent, IEvent, IContent, EventStatus } from "./models/event";
-import { ISendEventResponse } from "./@types/requests";
-import { EventType } from "./@types/event";
+import {
+    ISendEventResponse,
+    SendDelayedEventRequestOpts,
+    SendDelayedEventResponse,
+    UpdateDelayedEventAction,
+} from "./@types/requests";
+import { EventType, StateEvents } from "./@types/event";
 import { logger } from "./logger";
 import {
     MatrixClient,
@@ -36,6 +41,7 @@ import {
     IStartClientOpts,
     SendToDeviceContentMap,
     IOpenIDToken,
+    UNSTABLE_MSC4140_DELAYED_EVENTS,
 } from "./client";
 import { SyncApi, SyncState } from "./sync";
 import { SlidingSyncSdk } from "./sliding-sync-sdk";
@@ -95,6 +101,20 @@ export interface ICapabilities {
      * @defaultValue false
      */
     turnServers?: boolean;
+
+    /**
+     * Whether this client needs to be able to send delayed events.
+     * @experimental Part of MSC4140 & MSC4157
+     * @defaultValue false
+     */
+    sendDelayedEvents?: boolean;
+
+    /**
+     * Whether this client needs to be able to update delayed events.
+     * @experimental Part of MSC4140 & MSC4157
+     * @defaultValue false
+     */
+    updateDelayedEvents?: boolean;
 }
 
 /**
@@ -162,6 +182,18 @@ export class RoomWidgetClient extends MatrixClient {
         );
         capabilities.sendToDevice?.forEach((eventType) => widgetApi.requestCapabilityToSendToDevice(eventType));
         capabilities.receiveToDevice?.forEach((eventType) => widgetApi.requestCapabilityToReceiveToDevice(eventType));
+        if (
+            capabilities.sendDelayedEvents &&
+            (capabilities.sendEvent?.length ||
+                capabilities.sendMessage === true ||
+                (Array.isArray(capabilities.sendMessage) && capabilities.sendMessage.length) ||
+                capabilities.sendState?.length)
+        ) {
+            widgetApi.requestCapability(MatrixCapabilities.MSC4157SendDelayedEvent);
+        }
+        if (capabilities.updateDelayedEvents) {
+            widgetApi.requestCapability(MatrixCapabilities.MSC4157UpdateDelayedEvent);
+        }
         if (capabilities.turnServers) {
             widgetApi.requestCapability(MatrixCapabilities.MSC3846TurnServers);
         }
@@ -248,7 +280,29 @@ export class RoomWidgetClient extends MatrixClient {
         throw new Error(`Unknown room: ${roomIdOrAlias}`);
     }
 
-    protected async encryptAndSendEvent(room: Room, event: MatrixEvent): Promise<ISendEventResponse> {
+    protected async encryptAndSendEvent(room: Room, event: MatrixEvent): Promise<ISendEventResponse>;
+    protected async encryptAndSendEvent(
+        room: Room,
+        event: MatrixEvent,
+        delayOpts: SendDelayedEventRequestOpts,
+    ): Promise<SendDelayedEventResponse>;
+    protected async encryptAndSendEvent(
+        room: Room,
+        event: MatrixEvent,
+        delayOpts?: SendDelayedEventRequestOpts,
+    ): Promise<ISendEventResponse | SendDelayedEventResponse> {
+        if (delayOpts) {
+            // TODO: updatePendingEvent for delayed events?
+            const response = await this.widgetApi.sendRoomEvent(
+                event.getType(),
+                event.getContent(),
+                room.roomId,
+                "delay" in delayOpts ? delayOpts.delay : undefined,
+                "parent_delay_id" in delayOpts ? delayOpts.parent_delay_id : undefined,
+            );
+            return this.validateSendDelayedEventResponse(response);
+        }
+
         let response: ISendEventFromWidgetResponseData;
         try {
             response = await this.widgetApi.sendRoomEvent(event.getType(), event.getContent(), room.roomId);
@@ -257,8 +311,9 @@ export class RoomWidgetClient extends MatrixClient {
             throw e;
         }
 
+        // This also checks for an event id on the response
         room.updatePendingEvent(event, EventStatus.SENT, response.event_id);
-        return { event_id: response.event_id };
+        return { event_id: response.event_id! };
     }
 
     public async sendStateEvent(
@@ -267,7 +322,56 @@ export class RoomWidgetClient extends MatrixClient {
         content: any,
         stateKey = "",
     ): Promise<ISendEventResponse> {
-        return await this.widgetApi.sendStateEvent(eventType, stateKey, content, roomId);
+        const response = await this.widgetApi.sendStateEvent(eventType, stateKey, content, roomId);
+        if (response.event_id === undefined) {
+            throw new Error("'event_id' absent from response to an event request");
+        }
+        return { event_id: response.event_id };
+    }
+
+    /**
+     * @experimental This currently relies on an unstable MSC (MSC4140).
+     */
+    // eslint-disable-next-line
+    public async _unstable_sendDelayedStateEvent<K extends keyof StateEvents>(
+        roomId: string,
+        delayOpts: SendDelayedEventRequestOpts,
+        eventType: K,
+        content: StateEvents[K],
+        stateKey = "",
+    ): Promise<SendDelayedEventResponse> {
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
+            throw Error("Server does not support the delayed events API");
+        }
+
+        const response = await this.widgetApi.sendStateEvent(
+            eventType,
+            stateKey,
+            content,
+            roomId,
+            "delay" in delayOpts ? delayOpts.delay : undefined,
+            "parent_delay_id" in delayOpts ? delayOpts.parent_delay_id : undefined,
+        );
+        return this.validateSendDelayedEventResponse(response);
+    }
+
+    private validateSendDelayedEventResponse(response: ISendEventFromWidgetResponseData): SendDelayedEventResponse {
+        if (response.delay_id === undefined) {
+            throw new Error("'delay_id' absent from response to a delayed event request");
+        }
+        return { delay_id: response.delay_id };
+    }
+
+    /**
+     * @experimental This currently relies on an unstable MSC (MSC4140).
+     */
+    // eslint-disable-next-line
+    public async _unstable_updateDelayedEvent(delayId: string, action: UpdateDelayedEventAction): Promise<{}> {
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
+            throw Error("Server does not support the delayed events API");
+        }
+
+        return await this.widgetApi.updateDelayedEvent(delayId, action);
     }
 
     public async sendToDevice(eventType: string, contentMap: SendToDeviceContentMap): Promise<{}> {

src/matrixrtc/CallMembership.ts

@@ -156,8 +156,14 @@ export class CallMembership {
         return this.membershipData.created_ts ?? this.parentEvent.getTs();
     }
 
+    /**
+     * Gets the absolute expiry time of the membership if applicable to this membership type.
+     * @returns The absolute expiry time of the membership as a unix timestamp in milliseconds or undefined if not applicable
+     */
     public getAbsoluteExpiry(): number | undefined {
+        // if the membership is not a legacy membership, we assume it is MSC4143
         if (!isLegacyCallMembershipData(this.membershipData)) return undefined;
+
         if ("expires" in this.membershipData) {
             // we know createdTs exists since we already do the isLegacyCallMembershipData check
             return this.createdTs() + this.membershipData.expires;
@@ -167,9 +173,15 @@ export class CallMembership {
         }
     }
 
-    // gets the expiry time of the event, converted into the device's local time
+    /**
+     * Gets the expiry time of the event, converted into the device's local time.
+     * @deprecated This function has been observed returning bad data and is no longer used by MatrixRTC.
+     * @returns The local expiry time of the membership as a unix timestamp in milliseconds or undefined if not applicable
+     */
     public getLocalExpiry(): number | undefined {
+        // if the membership is not a legacy membership, we assume it is MSC4143
         if (!isLegacyCallMembershipData(this.membershipData)) return undefined;
+
         if ("expires" in this.membershipData) {
             // we know createdTs exists since we already do the isLegacyCallMembershipData check
             const relativeCreationTime = this.parentEvent.getTs() - this.createdTs();
@@ -184,10 +196,24 @@ export class CallMembership {
         }
     }
 
+    /**
+     * @returns The number of milliseconds until the membership expires or undefined if applicable
+     */
     public getMsUntilExpiry(): number | undefined {
-        if (isLegacyCallMembershipData(this.membershipData)) return this.getLocalExpiry()! - Date.now();
+        if (isLegacyCallMembershipData(this.membershipData)) {
+            // Assume that local clock is sufficiently in sync with other clocks in the distributed system.
+            // We used to try and adjust for the local clock being skewed, but there are cases where this is not accurate.
+            // The current implementation allows for the local clock to be -infinity to +MatrixRTCSession.MEMBERSHIP_EXPIRY_TIME/2
+            return this.getAbsoluteExpiry()! - Date.now();
+        }
+
+        // Assumed to be MSC4143
+        return undefined;
     }
 
+    /**
+     * @returns true if the membership has expired, otherwise false
+     */
     public isExpired(): boolean {
         if (isLegacyCallMembershipData(this.membershipData)) return this.getMsUntilExpiry()! <= 0;
 

src/matrixrtc/MatrixRTCSession.ts

@@ -20,6 +20,7 @@ import { EventTimeline } from "../models/event-timeline";
 import { Room } from "../models/room";
 import { MatrixClient } from "../client";
 import { EventType } from "../@types/event";
+import { UpdateDelayedEventAction } from "../@types/requests";
 import {
     CallMembership,
     CallMembershipData,
@@ -55,9 +56,9 @@ const USE_KEY_DELAY = 5000;
 const getParticipantId = (userId: string, deviceId: string): string => `${userId}:${deviceId}`;
 const getParticipantIdFromMembership = (m: CallMembership): string => getParticipantId(m.sender!, m.deviceId);
 
-function keysEqual(a: Uint8Array, b: Uint8Array): boolean {
+function keysEqual(a: Uint8Array | undefined, b: Uint8Array | undefined): boolean {
     if (a === b) return true;
-    return a && b && a.length === b.length && a.every((x, i) => x === b[i]);
+    return !!a && !!b && a.length === b.length && a.every((x, i) => x === b[i]);
 }
 
 export enum MatrixRTCSessionEvent {
@@ -133,10 +134,14 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
 
     private manageMediaKeys = false;
     private useLegacyMemberEvents = true;
-    // userId:deviceId => array of keys
-    private encryptionKeys = new Map<string, Array<Uint8Array>>();
+    // userId:deviceId => array of (key, timestamp)
+    private encryptionKeys = new Map<string, Array<{ key: Uint8Array; timestamp: number }>>();
     private lastEncryptionKeyUpdateRequest?: number;
 
+    // We use this to store the last membership fingerprints we saw, so we can proactively re-send encryption keys
+    // if it looks like a membership has been updated.
+    private lastMembershipFingerprints: Set<string> | undefined;
+
     /**
      * The callId (sessionId) of the call.
      *
@@ -160,26 +165,27 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
         const callMemberships: CallMembership[] = [];
         for (const memberEvent of callMemberEvents) {
             const content = memberEvent.getContent();
+            const eventKeysCount = Object.keys(content).length;
+            // Dont even bother about empty events (saves us from costly type/"key in" checks in bigger rooms)
+            if (eventKeysCount === 0) continue;
+
             let membershipContents: any[] = [];
+
             // We first decide if its a MSC4143 event (per device state key)
-            if ("memberships" in content) {
+            if (eventKeysCount > 1 && "focus_active" in content) {
+                // We have a MSC4143 event membership event
+                membershipContents.push(content);
+            } else if (eventKeysCount === 1 && "memberships" in content) {
                 // we have a legacy (one event for all devices) event
                 if (!Array.isArray(content["memberships"])) {
                     logger.warn(`Malformed member event from ${memberEvent.getSender()}: memberships is not an array`);
                     continue;
                 }
                 membershipContents = content["memberships"];
-            } else {
-                // We have a MSC4143 event membership event
-                if (Object.keys(content).length !== 0) {
-                    // We checked for empty content to not try to construct CallMembership's with {}.
-                    membershipContents.push(content);
-                }
-            }
-            if (membershipContents.length === 0) {
-                continue;
             }
 
+            if (membershipContents.length === 0) continue;
+
             for (const membershipData of membershipContents) {
                 try {
                     const membership = new CallMembership(memberEvent, membershipData);
@@ -372,8 +378,15 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
         }
     }
 
+    /**
+     * Get the known encryption keys for a given participant device.
+     *
+     * @param userId the user ID of the participant
+     * @param deviceId the device ID of the participant
+     * @returns The encryption keys for the given participant, or undefined if they are not known.
+     */
     public getKeysForParticipant(userId: string, deviceId: string): Array<Uint8Array> | undefined {
-        return this.encryptionKeys.get(getParticipantId(userId, deviceId));
+        return this.encryptionKeys.get(getParticipantId(userId, deviceId))?.map((entry) => entry.key);
     }
 
     /**
@@ -381,7 +394,10 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
      * cipher) given participant's media. This also includes our own key
      */
     public getEncryptionKeys(): IterableIterator<[string, Array<Uint8Array>]> {
-        return this.encryptionKeys.entries();
+        // the returned array doesn't contain the timestamps
+        return Array.from(this.encryptionKeys.entries())
+            .map(([participantId, keys]): [string, Uint8Array[]] => [participantId, keys.map((k) => k.key)])
+            .values();
     }
 
     private getNewEncryptionKeyIndex(): number {
@@ -396,13 +412,15 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
 
     /**
      * Sets an encryption key at a specified index for a participant.
-     * The encryption keys for the local participanmt are also stored here under the
+     * The encryption keys for the local participant are also stored here under the
      * user and device ID of the local participant.
+     * If the key is older than the existing key at the index, it will be ignored.
      * @param userId - The user ID of the participant
      * @param deviceId - Device ID of the participant
      * @param encryptionKeyIndex - The index of the key to set
      * @param encryptionKeyString - The string representation of the key to set in base64
-     * @param delayBeforeuse - If true, delay before emitting a key changed event. Useful when setting
+     * @param timestamp - The timestamp of the key. We assume that these are monotonic for each participant device.
+     * @param delayBeforeUse - If true, delay before emitting a key changed event. Useful when setting
      *                         encryption keys for the local participant to allow time for the key to
      *                         be distributed.
      */
@@ -411,18 +429,39 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
         deviceId: string,
         encryptionKeyIndex: number,
         encryptionKeyString: string,
-        delayBeforeuse = false,
+        timestamp: number,
+        delayBeforeUse = false,
     ): void {
         const keyBin = decodeBase64(encryptionKeyString);
 
         const participantId = getParticipantId(userId, deviceId);
-        const encryptionKeys = this.encryptionKeys.get(participantId) ?? [];
+        if (!this.encryptionKeys.has(participantId)) {
+            this.encryptionKeys.set(participantId, []);
+        }
+        const participantKeys = this.encryptionKeys.get(participantId)!;
 
-        if (keysEqual(encryptionKeys[encryptionKeyIndex], keyBin)) return;
+        const existingKeyAtIndex = participantKeys[encryptionKeyIndex];
 
-        encryptionKeys[encryptionKeyIndex] = keyBin;
-        this.encryptionKeys.set(participantId, encryptionKeys);
-        if (delayBeforeuse) {
+        if (existingKeyAtIndex) {
+            if (existingKeyAtIndex.timestamp > timestamp) {
+                logger.info(
+                    `Ignoring new key at index ${encryptionKeyIndex} for ${participantId} as it is older than existing known key`,
+                );
+                return;
+            }
+
+            if (keysEqual(existingKeyAtIndex.key, keyBin)) {
+                existingKeyAtIndex.timestamp = timestamp;
+                return;
+            }
+        }
+
+        participantKeys[encryptionKeyIndex] = {
+            key: keyBin,
+            timestamp,
+        };
+
+        if (delayBeforeUse) {
             const useKeyTimeout = setTimeout(() => {
                 this.setNewKeyTimeouts.delete(useKeyTimeout);
                 logger.info(`Delayed-emitting key changed event for ${participantId} idx ${encryptionKeyIndex}`);
@@ -449,7 +488,7 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
         const encryptionKey = secureRandomBase64Url(16);
         const encryptionKeyIndex = this.getNewEncryptionKeyIndex();
         logger.info("Generated new key at index " + encryptionKeyIndex);
-        this.setEncryptionKey(userId, deviceId, encryptionKeyIndex, encryptionKey, delayBeforeUse);
+        this.setEncryptionKey(userId, deviceId, encryptionKeyIndex, encryptionKey, Date.now(), delayBeforeUse);
     }
 
     /**
@@ -568,6 +607,13 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
         }
     }
 
+    /**
+     * Process `m.call.encryption_keys` events to track the encryption keys for call participants.
+     * This should be called each time the relevant event is received from a room timeline.
+     * If the event is malformed then it will be logged and ignored.
+     *
+     * @param event the event to process
+     */
     public onCallEncryption = (event: MatrixEvent): void => {
         const userId = event.getSender();
         const content = event.getContent<EncryptionKeysEventContent>();
@@ -629,11 +675,19 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
                     `Embedded-E2EE-LOG onCallEncryption userId=${userId}:${deviceId} encryptionKeyIndex=${encryptionKeyIndex}`,
                     this.encryptionKeys,
                 );
-                this.setEncryptionKey(userId, deviceId, encryptionKeyIndex, encryptionKey);
+                this.setEncryptionKey(userId, deviceId, encryptionKeyIndex, encryptionKey, event.getTs());
             }
         }
     };
 
+    private isMyMembership = (m: CallMembership): boolean =>
+        m.sender === this.client.getUserId() && m.deviceId === this.client.getDeviceId();
+
+    /**
+     * Examines the latest call memberships and handles any encryption key sending or rotation that is needed.
+     *
+     * This function should be called when the room members or call memberships might have changed.
+     */
     public onMembershipUpdate = (): void => {
         const oldMemberships = this.memberships;
         this.memberships = MatrixRTCSession.callMembershipsForRoom(this.room);
@@ -649,19 +703,22 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
             this.emit(MatrixRTCSessionEvent.MembershipsChanged, oldMemberships, this.memberships);
         }
 
-        const isMyMembership = (m: CallMembership): boolean =>
-            m.sender === this.client.getUserId() && m.deviceId === this.client.getDeviceId();
-
         if (this.manageMediaKeys && this.isJoined() && this.makeNewKeyTimeout === undefined) {
-            const oldMebershipIds = new Set(
-                oldMemberships.filter((m) => !isMyMembership(m)).map(getParticipantIdFromMembership),
+            const oldMembershipIds = new Set(
+                oldMemberships.filter((m) => !this.isMyMembership(m)).map(getParticipantIdFromMembership),
             );
-            const newMebershipIds = new Set(
-                this.memberships.filter((m) => !isMyMembership(m)).map(getParticipantIdFromMembership),
+            const newMembershipIds = new Set(
+                this.memberships.filter((m) => !this.isMyMembership(m)).map(getParticipantIdFromMembership),
             );
 
-            const anyLeft = Array.from(oldMebershipIds).some((x) => !newMebershipIds.has(x));
-            const anyJoined = Array.from(newMebershipIds).some((x) => !oldMebershipIds.has(x));
+            // We can use https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set/symmetricDifference
+            // for this once available
+            const anyLeft = Array.from(oldMembershipIds).some((x) => !newMembershipIds.has(x));
+            const anyJoined = Array.from(newMembershipIds).some((x) => !oldMembershipIds.has(x));
+
+            const oldFingerprints = this.lastMembershipFingerprints;
+            // always store the fingerprints of these latest memberships
+            this.storeLastMembershipFingerprints();
 
             if (anyLeft) {
                 logger.debug(`Member(s) have left: queueing sender key rotation`);
@@ -669,12 +726,33 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
             } else if (anyJoined) {
                 logger.debug(`New member(s) have joined: re-sending keys`);
                 this.requestKeyEventSend();
+            } else if (oldFingerprints) {
+                // does it look like any of the members have updated their memberships?
+                const newFingerprints = this.lastMembershipFingerprints!;
+
+                // We can use https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set/symmetricDifference
+                // for this once available
+                const candidateUpdates =
+                    Array.from(oldFingerprints).some((x) => !newFingerprints.has(x)) ||
+                    Array.from(newFingerprints).some((x) => !oldFingerprints.has(x));
+                if (candidateUpdates) {
+                    logger.debug(`Member(s) have updated/reconnected: re-sending keys`);
+                    this.requestKeyEventSend();
+                }
             }
         }
 
         this.setExpiryTimer();
     };
 
+    private storeLastMembershipFingerprints(): void {
+        this.lastMembershipFingerprints = new Set(
+            this.memberships
+                .filter((m) => !this.isMyMembership(m))
+                .map((m) => `${getParticipantIdFromMembership(m)}:${m.membershipID}:${m.createdTs()}`),
+        );
+    }
+
     /**
      * Constructs our own membership
      * @param prevMembership - The previous value of our call membership, if any
@@ -824,9 +902,7 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
         if (!localUserId || !localDeviceId) throw new Error("User ID or device ID was null!");
 
         const callMemberEvents = roomState.events.get(EventType.GroupCallMemberPrefix);
-        const legacy =
-            !!this.useLegacyMemberEvents ||
-            (callMemberEvents?.size && this.stateEventsContainOngoingLegacySession(callMemberEvents));
+        const legacy = this.stateEventsContainOngoingLegacySession(callMemberEvents);
         let newContent: {} | ExperimentalGroupCallRoomMemberState | SessionMembershipData = {};
         if (legacy) {
             const myCallMemberEvent = callMemberEvents?.get(localUserId);
@@ -864,28 +940,64 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
             newContent = this.makeNewMembership(localDeviceId);
         }
 
+        const stateKey = legacy ? localUserId : this.makeMembershipStateKey(localUserId, localDeviceId);
         try {
-            await this.client.sendStateEvent(
-                this.room.roomId,
-                EventType.GroupCallMemberPrefix,
-                newContent,
-                legacy ? localUserId : this.makeMembershipStateKey(localUserId, localDeviceId),
-            );
+            await this.client.sendStateEvent(this.room.roomId, EventType.GroupCallMemberPrefix, newContent, stateKey);
             logger.info(`Sent updated call member event.`);
 
             // check periodically to see if we need to refresh our member event
-            if (this.isJoined() && legacy) {
-                this.memberEventTimeout = setTimeout(this.triggerCallMembershipEventUpdate, MEMBER_EVENT_CHECK_PERIOD);
+            if (this.isJoined()) {
+                if (legacy) {
+                    this.memberEventTimeout = setTimeout(
+                        this.triggerCallMembershipEventUpdate,
+                        MEMBER_EVENT_CHECK_PERIOD,
+                    );
+                } else {
+                    try {
+                        // TODO: If delayed event times out, re-join!
+                        const res = await this.client._unstable_sendDelayedStateEvent(
+                            this.room.roomId,
+                            {
+                                delay: 8000,
+                            },
+                            EventType.GroupCallMemberPrefix,
+                            {}, // leave event
+                            stateKey,
+                        );
+                        this.scheduleDelayDisconnection(res.delay_id);
+                    } catch (e) {
+                        logger.error("Failed to send delayed event:", e);
+                    }
+                }
             }
         } catch (e) {
             const resendDelay = CALL_MEMBER_EVENT_RETRY_DELAY_MIN + Math.random() * 2000;
-            logger.warn(`Failed to send call member event: retrying in ${resendDelay}`);
+            logger.warn(`Failed to send call member event (retrying in ${resendDelay}): ${e}`);
             await new Promise((resolve) => setTimeout(resolve, resendDelay));
             await this.triggerCallMembershipEventUpdate();
         }
     }
 
-    private stateEventsContainOngoingLegacySession(callMemberEvents: Map<string, MatrixEvent>): boolean {
+    private scheduleDelayDisconnection(delayId: string): void {
+        this.memberEventTimeout = setTimeout(() => this.delayDisconnection(delayId), 5000);
+    }
+
+    private async delayDisconnection(delayId: string): Promise<void> {
+        try {
+            await this.client._unstable_updateDelayedEvent(delayId, UpdateDelayedEventAction.Restart);
+            this.scheduleDelayDisconnection(delayId);
+        } catch (e) {
+            logger.error("Failed to delay our disconnection event", e);
+        }
+    }
+
+    private stateEventsContainOngoingLegacySession(callMemberEvents: Map<string, MatrixEvent> | undefined): boolean {
+        if (!callMemberEvents?.size) {
+            return this.useLegacyMemberEvents;
+        }
+
+        let containsAnyOngoingSession = false;
+        let containsUnknownOngoingSession = false;
         for (const callMemberEvent of callMemberEvents.values()) {
             const content = callMemberEvent.getContent();
             if (Array.isArray(content["memberships"])) {
@@ -894,14 +1006,17 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
                         return true;
                     }
                 }
+            } else if (Object.keys(content).length > 0) {
+                containsAnyOngoingSession ||= true;
+                containsUnknownOngoingSession ||= !("focus_active" in content);
             }
         }
-        return false;
+        return containsAnyOngoingSession && !containsUnknownOngoingSession ? false : this.useLegacyMemberEvents;
     }
 
     private makeMembershipStateKey(localUserId: string, localDeviceId: string): string {
         const stateKey = `${localUserId}_${localDeviceId}`;
-        if (/^org\.matrix\.msc3779\b/.exec(this.room.getVersion())) {
+        if (/^org\.matrix\.msc(3757|3779)\b/.exec(this.room.getVersion())) {
             return stateKey;
         } else {
             return `_${stateKey}`;

src/matrixrtc/MatrixRTCSessionManager.ts

@@ -98,8 +98,23 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
         return this.roomSessions.get(room.roomId)!;
     }
 
-    private async consumeCallEncryptionEvent(event: MatrixEvent): Promise<void> {
+    private async consumeCallEncryptionEvent(event: MatrixEvent, isRetry = false): Promise<void> {
         await this.client.decryptEventIfNeeded(event);
+        if (event.isDecryptionFailure()) {
+            if (!isRetry) {
+                logger.warn(
+                    `Decryption failed for event ${event.getId()}: ${event.decryptionFailureReason} will retry once only`,
+                );
+                // retry after 1 second. After this we give up.
+                setTimeout(() => this.consumeCallEncryptionEvent(event, true), 1000);
+            } else {
+                logger.warn(`Decryption failed for event ${event.getId()}: ${event.decryptionFailureReason}`);
+            }
+            return;
+        } else if (isRetry) {
+            logger.info(`Decryption succeeded for event ${event.getId()} after retry`);
+        }
+
         if (event.getType() !== EventType.CallEncryptionKeysPrefix) return Promise.resolve();
 
         const room = this.client.getRoom(event.getRoomId());

src/matrixrtc/index.ts

@@ -0,0 +1,22 @@
+/*
+Copyright 2024 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+export * from "./CallMembership";
+export * from "./focus";
+export * from "./LivekitFocus";
+export * from "./MatrixRTCSession";
+export * from "./MatrixRTCSessionManager";
+export * from "./types";

src/models/event.ts

@@ -43,7 +43,6 @@ import { MatrixError } from "../http-api";
 import { TypedEventEmitter } from "./typed-event-emitter";
 import { EventStatus } from "./event-status";
 import { CryptoBackend, DecryptionError } from "../common-crypto/CryptoBackend";
-import { WITHHELD_MESSAGES } from "../crypto/OlmDevice";
 import { IAnnotatedPushRule } from "../@types/PushRules";
 import { Room } from "./room";
 import { EventTimeline } from "./event-timeline";
@@ -312,12 +311,6 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
     private thread?: Thread;
     private threadId?: string;
 
-    /*
-     * True if this event is an encrypted event which we failed to decrypt, the receiver's device is unverified and
-     * the sender has disabled encrypting to unverified devices.
-     */
-    private encryptedDisabledForUnverifiedDevices = false;
-
     /* Set an approximate timestamp for the event relative the local clock.
      * This will inherently be approximate because it doesn't take into account
      * the time between the server putting the 'age' field on the event as it sent
@@ -411,7 +404,7 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
         // The fallback in these cases will be to use the origin_server_ts.
         // For EDUs, the origin_server_ts also is not defined so we use Date.now().
         const age = this.getAge();
-        this.localTimestamp = age !== undefined ? Date.now() - age : this.getTs() ?? Date.now();
+        this.localTimestamp = age !== undefined ? Date.now() - age : (this.getTs() ?? Date.now());
         this.reEmitter = new TypedReEmitter(this);
     }
 
@@ -787,12 +780,14 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
         return this._decryptionFailureReason;
     }
 
-    /*
+    /**
      * True if this event is an encrypted event which we failed to decrypt, the receiver's device is unverified and
      * the sender has disabled encrypting to unverified devices.
+     *
+     * @deprecated: Prefer `event.decryptionFailureReason === DecryptionFailureCode.MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE`.
      */
     public get isEncryptedDisabledForUnverifiedDevices(): boolean {
-        return this.isDecryptionFailure() && this.encryptedDisabledForUnverifiedDevices;
+        return this.decryptionFailureReason === DecryptionFailureCode.MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE;
     }
 
     public shouldAttemptDecryption(): boolean {
@@ -982,7 +977,6 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
         this.claimedEd25519Key = decryptionResult.claimedEd25519Key ?? null;
         this.forwardingCurve25519KeyChain = decryptionResult.forwardingCurve25519KeyChain || [];
         this.untrusted = decryptionResult.untrusted || false;
-        this.encryptedDisabledForUnverifiedDevices = false;
         this.invalidateExtensibleEvent();
     }
 
@@ -1003,7 +997,6 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
         this.claimedEd25519Key = null;
         this.forwardingCurve25519KeyChain = [];
         this.untrusted = false;
-        this.encryptedDisabledForUnverifiedDevices = reason === `DecryptionError: ${WITHHELD_MESSAGES["m.unverified"]}`;
         this.invalidateExtensibleEvent();
     }
 

src/models/room.ts

@@ -24,7 +24,7 @@ import {
 } from "./event-timeline-set";
 import { Direction, EventTimeline } from "./event-timeline";
 import { getHttpUriForMxc } from "../content-repo";
-import { compare, removeElement } from "../utils";
+import { removeElement } from "../utils";
 import { normalize, noUnsafeEventProps } from "../utils";
 import { IEvent, IThreadBundledRelationship, MatrixEvent, MatrixEventEvent, MatrixEventHandlerMap } from "./event";
 import { EventStatus } from "./event-status";
@@ -3451,7 +3451,8 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
                 return true;
             });
             // make sure members have stable order
-            otherMembers.sort((a, b) => compare(a.userId, b.userId));
+            const collator = new Intl.Collator();
+            otherMembers.sort((a, b) => collator.compare(a.userId, b.userId));
             // only 5 first members, immitate summaryHeroes
             otherMembers = otherMembers.slice(0, 5);
             otherNames = otherMembers.map((m) => m.name);

src/oidc/authorize.ts

@@ -27,6 +27,8 @@ import {
     validateIdToken,
     validateStoredUserState,
 } from "./validate";
+import { sha256 } from "../digest";
+import { encodeUnpaddedBase64Url } from "../base64";
 
 // reexport for backwards compatibility
 export type { BearerTokenResponse };
@@ -61,14 +63,9 @@ const generateCodeChallenge = async (codeVerifier: string): Promise<string> => {
         logger.warn("A secure context is required to generate code challenge. Using plain text code challenge");
         return codeVerifier;
     }
-    const utf8 = new TextEncoder().encode(codeVerifier);
 
-    const digest = await globalThis.crypto.subtle.digest("SHA-256", utf8);
-
-    return btoa(String.fromCharCode(...new Uint8Array(digest)))
-        .replace(/=/g, "")
-        .replace(/\+/g, "-")
-        .replace(/\//g, "_");
+    const hashBuffer = await sha256(codeVerifier);
+    return encodeUnpaddedBase64Url(hashBuffer);
 };
 
 /**

src/rust-crypto/RoomEncryptor.ts

@@ -14,16 +14,17 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-wasm";
 import {
+    CollectStrategy,
     EncryptionAlgorithm,
     EncryptionSettings,
+    HistoryVisibility as RustHistoryVisibility,
     OlmMachine,
     RoomId,
-    UserId,
-    HistoryVisibility as RustHistoryVisibility,
     ToDeviceRequest,
+    UserId,
 } from "@matrix-org/matrix-sdk-crypto-wasm";
-import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-wasm";
 
 import { EventType } from "../@types/event";
 import { IContent, MatrixEvent } from "../models/event";
@@ -142,7 +143,7 @@ export class RoomEncryptor {
      * @param globalBlacklistUnverifiedDevices - When `true`, it will not send encrypted messages to unverified devices
      */
     public encryptEvent(event: MatrixEvent | null, globalBlacklistUnverifiedDevices: boolean): Promise<void> {
-        const logger = new LogSpan(this.prefixedLogger, event ? event.getTxnId() ?? "" : "prepareForEncryption");
+        const logger = new LogSpan(this.prefixedLogger, event ? (event.getTxnId() ?? "") : "prepareForEncryption");
         // Ensure order of encryption to avoid message ordering issues, as the scheduler only ensures
         // events order after they have been encrypted.
         const prom = this.currentEncryptionPromise
@@ -252,8 +253,11 @@ export class RoomEncryptor {
 
         // When this.room.getBlacklistUnverifiedDevices() === null, the global settings should be used
         // See Room#getBlacklistUnverifiedDevices
-        rustEncryptionSettings.onlyAllowTrustedDevices =
-            this.room.getBlacklistUnverifiedDevices() ?? globalBlacklistUnverifiedDevices;
+        if (this.room.getBlacklistUnverifiedDevices() ?? globalBlacklistUnverifiedDevices) {
+            rustEncryptionSettings.sharingStrategy = CollectStrategy.DeviceBasedStrategyOnlyTrustedDevices;
+        } else {
+            rustEncryptionSettings.sharingStrategy = CollectStrategy.DeviceBasedStrategyAllDevices;
+        }
 
         await logDuration(this.prefixedLogger, "shareRoomKey", async () => {
             const shareMessages: ToDeviceRequest[] = await this.olmMachine.shareRoomKey(

src/rust-crypto/index.ts

@@ -174,6 +174,9 @@ async function initOlmMachine(
     await olmMachine.registerRoomKeyUpdatedCallback((sessions: RustSdkCryptoJs.RoomKeyInfo[]) =>
         rustCrypto.onRoomKeysUpdated(sessions),
     );
+    await olmMachine.registerRoomKeysWithheldCallback((withheld: RustSdkCryptoJs.RoomKeyWithheldInfo[]) =>
+        rustCrypto.onRoomKeysWithheld(withheld),
+    );
     await olmMachine.registerUserIdentityUpdatedCallback((userId: RustSdkCryptoJs.UserId) =>
         rustCrypto.onUserIdentityUpdated(userId),
     );

src/rust-crypto/rust-crypto.ts

@@ -1486,7 +1486,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
         this.logger.debug(
             `Got update for session ${key.senderKey.toBase64()}|${key.sessionId} in ${key.roomId.toString()}`,
         );
-        const pendingList = this.eventDecryptor.getEventsPendingRoomKey(key);
+        const pendingList = this.eventDecryptor.getEventsPendingRoomKey(key.roomId.toString(), key.sessionId);
         if (pendingList.length === 0) return;
 
         this.logger.debug(
@@ -1507,6 +1507,37 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
         }
     }
 
+    /**
+     * Callback for `OlmMachine.registerRoomKeyWithheldCallback`.
+     *
+     * Called by the rust sdk whenever we are told that a key has been withheld. We see if we had any events that
+     * failed to decrypt for the given session, and update their status if so.
+     *
+     * @param withheld - Details of the withheld sessions.
+     */
+    public async onRoomKeysWithheld(withheld: RustSdkCryptoJs.RoomKeyWithheldInfo[]): Promise<void> {
+        for (const session of withheld) {
+            this.logger.debug(`Got withheld message for session ${session.sessionId} in ${session.roomId.toString()}`);
+            const pendingList = this.eventDecryptor.getEventsPendingRoomKey(
+                session.roomId.toString(),
+                session.sessionId,
+            );
+            if (pendingList.length === 0) return;
+
+            // The easiest way to update the status of the event is to have another go at decrypting it.
+            this.logger.debug(
+                "Retrying decryption on events:",
+                pendingList.map((e) => `${e.getId()}`),
+            );
+
+            for (const ev of pendingList) {
+                ev.attemptDecryption(this, { isRetry: true }).catch((_e) => {
+                    // It's somewhat expected that we still can't decrypt here.
+                });
+            }
+        }
+    }
+
     /**
      * Callback for `OlmMachine.registerUserIdentityUpdatedCallback`
      *
@@ -1683,7 +1714,7 @@ class EventDecryptor {
     /**
      * Events which we couldn't decrypt due to unknown sessions / indexes.
      *
-     * Map from senderKey to sessionId to Set of MatrixEvents
+     * Map from roomId to sessionId to Set of MatrixEvents
      */
     private eventsPendingKey = new MapWithDefault<string, MapWithDefault<string, Set<MatrixEvent>>>(
         () => new MapWithDefault<string, Set<MatrixEvent>>(() => new Set()),
@@ -1787,6 +1818,17 @@ class EventDecryptor {
             }
         }
 
+        // If we got a withheld code, expose that.
+        if (err.maybe_withheld) {
+            // Unfortunately the Rust SDK API doesn't let us distinguish between different withheld cases, other than
+            // by string-matching.
+            const failureCode =
+                err.maybe_withheld === "The sender has disabled encrypting to unverified devices."
+                    ? DecryptionFailureCode.MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE
+                    : DecryptionFailureCode.MEGOLM_KEY_WITHHELD;
+            throw new DecryptionError(failureCode, err.maybe_withheld, errorDetails);
+        }
+
         switch (err.code) {
             case RustSdkCryptoJs.DecryptionErrorCode.MissingRoomKey:
                 throw new DecryptionError(
@@ -1832,30 +1874,27 @@ class EventDecryptor {
      * Look for events which are waiting for a given megolm session
      *
      * Returns a list of events which were encrypted by `session` and could not be decrypted
-     *
-     * @param session -
      */
-    public getEventsPendingRoomKey(session: RustSdkCryptoJs.RoomKeyInfo): MatrixEvent[] {
-        const senderPendingEvents = this.eventsPendingKey.get(session.senderKey.toBase64());
-        if (!senderPendingEvents) return [];
+    public getEventsPendingRoomKey(roomId: string, sessionId: string): MatrixEvent[] {
+        const roomPendingEvents = this.eventsPendingKey.get(roomId);
+        if (!roomPendingEvents) return [];
 
-        const sessionPendingEvents = senderPendingEvents.get(session.sessionId);
+        const sessionPendingEvents = roomPendingEvents.get(sessionId);
         if (!sessionPendingEvents) return [];
 
-        const roomId = session.roomId.toString();
-        return [...sessionPendingEvents].filter((ev) => ev.getRoomId() === roomId);
+        return [...sessionPendingEvents];
     }
 
     /**
      * Add an event to the list of those awaiting their session keys.
      */
     private addEventToPendingList(event: MatrixEvent): void {
-        const content = event.getWireContent();
-        const senderKey = content.sender_key;
-        const sessionId = content.session_id;
+        const roomId = event.getRoomId();
+        // We shouldn't have events without a room id here.
+        if (!roomId) return;
 
-        const senderPendingEvents = this.eventsPendingKey.getOrCreate(senderKey);
-        const sessionPendingEvents = senderPendingEvents.getOrCreate(sessionId);
+        const roomPendingEvents = this.eventsPendingKey.getOrCreate(roomId);
+        const sessionPendingEvents = roomPendingEvents.getOrCreate(event.getWireContent().session_id);
         sessionPendingEvents.add(event);
     }
 
@@ -1863,23 +1902,22 @@ class EventDecryptor {
      * Remove an event from the list of those awaiting their session keys.
      */
     private removeEventFromPendingList(event: MatrixEvent): void {
-        const content = event.getWireContent();
-        const senderKey = content.sender_key;
-        const sessionId = content.session_id;
+        const roomId = event.getRoomId();
+        if (!roomId) return;
 
-        const senderPendingEvents = this.eventsPendingKey.get(senderKey);
-        if (!senderPendingEvents) return;
+        const roomPendingEvents = this.eventsPendingKey.getOrCreate(roomId);
+        if (!roomPendingEvents) return;
 
-        const sessionPendingEvents = senderPendingEvents.get(sessionId);
+        const sessionPendingEvents = roomPendingEvents.get(event.getWireContent().session_id);
         if (!sessionPendingEvents) return;
 
         sessionPendingEvents.delete(event);
 
         // also clean up the higher-level maps if they are now empty
         if (sessionPendingEvents.size === 0) {
-            senderPendingEvents.delete(sessionId);
-            if (senderPendingEvents.size === 0) {
-                this.eventsPendingKey.delete(senderKey);
+            roomPendingEvents.delete(event.getWireContent().session_id);
+            if (roomPendingEvents.size === 0) {
+                this.eventsPendingKey.delete(roomId);
             }
         }
     }

src/sync-accumulator.ts

@@ -504,7 +504,7 @@ export class SyncAccumulator {
 
             currentData._timeline.push({
                 event: transformedEvent,
-                token: index === 0 ? data.timeline.prev_batch ?? null : null,
+                token: index === 0 ? (data.timeline.prev_batch ?? null) : null,
             });
         });
 

src/sync.ts

@@ -1403,7 +1403,9 @@ export class SyncApi {
                 if (limited) {
                     room.resetLiveTimeline(
                         joinObj.timeline.prev_batch,
-                        this.syncOpts.canResetEntireTimeline!(room.roomId) ? null : syncEventData.oldSyncToken ?? null,
+                        this.syncOpts.canResetEntireTimeline!(room.roomId)
+                            ? null
+                            : (syncEventData.oldSyncToken ?? null),
                     );
 
                     // We have to assume any gap in any timeline is

src/utils.ts

@@ -649,16 +649,6 @@ export function lexicographicCompare(a: string, b: string): number {
     }
 }
 
-const collator = new Intl.Collator();
-/**
- * Performant language-sensitive string comparison
- * @param a - the first string to compare
- * @param b - the second string to compare
- */
-export function compare(a: string, b: string): number {
-    return collator.compare(a, b);
-}
-
 /**
  * This function is similar to Object.assign() but it assigns recursively and
  * allows you to ignore nullish values from the source