Add E2EE for embedded mode of Element Call

spec/unit/base64.spec.ts

@@ -17,7 +17,7 @@ limitations under the License.
 import { TextEncoder, TextDecoder } from "util";
 import NodeBuffer from "node:buffer";
 
-import { decodeBase64, encodeBase64, encodeUnpaddedBase64 } from "../../src/base64";
+import { decodeBase64, encodeBase64, encodeUnpaddedBase64, encodeUnpaddedBase64Url } from "../../src/base64";
 
 describe.each(["browser", "node"])("Base64 encoding (%s)", (env) => {
     let origBuffer = Buffer;
@@ -43,19 +43,27 @@ describe.each(["browser", "node"])("Base64 encoding (%s)", (env) => {
         global.btoa = undefined;
     });
 
-    it("Should decode properly encoded data", async () => {
+    it("Should decode properly encoded data", () => {
         const decoded = new TextDecoder().decode(decodeBase64("ZW5jb2RpbmcgaGVsbG8gd29ybGQ="));
 
         expect(decoded).toStrictEqual("encoding hello world");
     });
 
-    it("Should decode URL-safe base64", async () => {
+    it("Should encode unpadded URL-safe base64", () => {
+        const toEncode = "?????";
+        const data = new TextEncoder().encode(toEncode);
+
+        const encoded = encodeUnpaddedBase64Url(data);
+        expect(encoded).toEqual("Pz8_Pz8");
+    });
+
+    it("Should decode URL-safe base64", () => {
         const decoded = new TextDecoder().decode(decodeBase64("Pz8_Pz8="));
 
         expect(decoded).toStrictEqual("?????");
     });
 
-    it("Encode unpadded should not have padding", async () => {
+    it("Encode unpadded should not have padding", () => {
         const toEncode = "encoding hello world";
         const data = new TextEncoder().encode(toEncode);
 
@@ -68,7 +76,7 @@ describe.each(["browser", "node"])("Base64 encoding (%s)", (env) => {
         expect(padding).toStrictEqual("=");
     });
 
-    it("Decode should be indifferent to padding", async () => {
+    it("Decode should be indifferent to padding", () => {
         const withPadding = "ZW5jb2RpbmcgaGVsbG8gd29ybGQ=";
         const withoutPadding = "ZW5jb2RpbmcgaGVsbG8gd29ybGQ";
 

spec/unit/matrixrtc/MatrixRTCSession.spec.ts

@@ -14,11 +14,11 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { EventTimeline, EventType, MatrixClient, Room } from "../../../src";
+import { EventTimeline, EventType, MatrixClient, MatrixError, MatrixEvent, Room } from "../../../src";
 import { CallMembershipData } from "../../../src/matrixrtc/CallMembership";
 import { MatrixRTCSession, MatrixRTCSessionEvent } from "../../../src/matrixrtc/MatrixRTCSession";
 import { randomString } from "../../../src/randomstring";
-import { makeMockRoom, mockRTCEvent } from "./mocks";
+import { makeMockRoom, makeMockRoomState, mockRTCEvent } from "./mocks";
 
 const membershipTemplate: CallMembershipData = {
     call_id: "",
@@ -184,8 +184,15 @@ describe("MatrixRTCSession", () => {
 
     describe("joining", () => {
         let mockRoom: Room;
+        let sendStateEventMock: jest.Mock;
+        let sendEventMock: jest.Mock;
 
         beforeEach(() => {
+            sendStateEventMock = jest.fn();
+            sendEventMock = jest.fn();
+            client.sendStateEvent = sendStateEventMock;
+            client.sendEvent = sendEventMock;
+
             mockRoom = makeMockRoom([]);
             sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
         });
@@ -205,8 +212,6 @@ describe("MatrixRTCSession", () => {
         });
 
         it("sends a membership event when joining a call", () => {
-            client.sendStateEvent = jest.fn();
-
             sess!.joinRoomSession([mockFocus]);
 
             expect(client.sendStateEvent).toHaveBeenCalledWith(
@@ -230,9 +235,6 @@ describe("MatrixRTCSession", () => {
         });
 
         it("does nothing if join called when already joined", () => {
-            const sendStateEventMock = jest.fn();
-            client.sendStateEvent = sendStateEventMock;
-
             sess!.joinRoomSession([mockFocus]);
 
             expect(client.sendStateEvent).toHaveBeenCalledTimes(1);
@@ -299,6 +301,188 @@ describe("MatrixRTCSession", () => {
                 jest.useRealTimers();
             }
         });
+
+        it("creates a key when joining", () => {
+            sess!.joinRoomSession([mockFocus], true);
+            const keys = sess?.getKeysForParticipant("@alice:example.org", "AAAAAAA");
+            expect(keys).toHaveLength(1);
+
+            const allKeys = sess!.getEncryptionKeys();
+            expect(allKeys).toBeTruthy();
+            expect(Array.from(allKeys)).toHaveLength(1);
+        });
+
+        it("sends keys when joining", async () => {
+            const eventSentPromise = new Promise((resolve) => {
+                sendEventMock.mockImplementation(resolve);
+            });
+
+            sess!.joinRoomSession([mockFocus], true);
+
+            await eventSentPromise;
+
+            expect(sendEventMock).toHaveBeenCalledWith(expect.stringMatching(".*"), "io.element.call.encryption_keys", {
+                call_id: "",
+                device_id: "AAAAAAA",
+                keys: [
+                    {
+                        index: 0,
+                        key: expect.stringMatching(".*"),
+                    },
+                ],
+            });
+        });
+
+        it("retries key sends", async () => {
+            jest.useFakeTimers();
+            let firstEventSent = false;
+
+            try {
+                const eventSentPromise = new Promise<void>((resolve) => {
+                    sendEventMock.mockImplementation(() => {
+                        if (!firstEventSent) {
+                            jest.advanceTimersByTime(10000);
+
+                            firstEventSent = true;
+                            const e = new Error() as MatrixError;
+                            e.data = {};
+                            throw e;
+                        } else {
+                            resolve();
+                        }
+                    });
+                });
+
+                sess!.joinRoomSession([mockFocus], true);
+                jest.advanceTimersByTime(10000);
+
+                await eventSentPromise;
+
+                expect(sendEventMock).toHaveBeenCalledTimes(2);
+            } finally {
+                jest.useRealTimers();
+            }
+        });
+
+        it("cancels key send event that fail", async () => {
+            const eventSentinel = {} as unknown as MatrixEvent;
+
+            client.cancelPendingEvent = jest.fn();
+            sendEventMock.mockImplementation(() => {
+                const e = new Error() as MatrixError;
+                e.data = {};
+                e.event = eventSentinel;
+                throw e;
+            });
+
+            sess!.joinRoomSession([mockFocus], true);
+
+            expect(client.cancelPendingEvent).toHaveBeenCalledWith(eventSentinel);
+        });
+
+        it("Re-sends key if a new member joins", async () => {
+            jest.useFakeTimers();
+            try {
+                const mockRoom = makeMockRoom([membershipTemplate]);
+                sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
+
+                const keysSentPromise1 = new Promise((resolve) => {
+                    sendEventMock.mockImplementation(resolve);
+                });
+
+                sess.joinRoomSession([mockFocus], true);
+                await keysSentPromise1;
+
+                sendEventMock.mockClear();
+                jest.advanceTimersByTime(10000);
+
+                const keysSentPromise2 = new Promise((resolve) => {
+                    sendEventMock.mockImplementation(resolve);
+                });
+
+                const onMembershipsChanged = jest.fn();
+                sess.on(MatrixRTCSessionEvent.MembershipsChanged, onMembershipsChanged);
+
+                const member2 = Object.assign({}, membershipTemplate, {
+                    device_id: "BBBBBBB",
+                });
+
+                mockRoom.getLiveTimeline().getState = jest
+                    .fn()
+                    .mockReturnValue(makeMockRoomState([membershipTemplate, member2], mockRoom.roomId, undefined));
+                sess.onMembershipUpdate();
+
+                await keysSentPromise2;
+
+                expect(sendEventMock).toHaveBeenCalled();
+            } finally {
+                jest.useRealTimers();
+            }
+        });
+
+        it("Doesn't re-send key immediately", async () => {
+            const realSetImmediate = setImmediate;
+            jest.useFakeTimers();
+            try {
+                const mockRoom = makeMockRoom([membershipTemplate]);
+                sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
+
+                const keysSentPromise1 = new Promise((resolve) => {
+                    sendEventMock.mockImplementation(resolve);
+                });
+
+                sess.joinRoomSession([mockFocus], true);
+                await keysSentPromise1;
+
+                sendEventMock.mockClear();
+
+                const onMembershipsChanged = jest.fn();
+                sess.on(MatrixRTCSessionEvent.MembershipsChanged, onMembershipsChanged);
+
+                const member2 = Object.assign({}, membershipTemplate, {
+                    device_id: "BBBBBBB",
+                });
+
+                mockRoom.getLiveTimeline().getState = jest
+                    .fn()
+                    .mockReturnValue(makeMockRoomState([membershipTemplate, member2], mockRoom.roomId, undefined));
+                sess.onMembershipUpdate();
+
+                await new Promise((resolve) => {
+                    realSetImmediate(resolve);
+                });
+
+                expect(sendEventMock).not.toHaveBeenCalled();
+            } finally {
+                jest.useRealTimers();
+            }
+        });
+    });
+
+    it("Does not emits if no membership changes", () => {
+        const mockRoom = makeMockRoom([membershipTemplate]);
+        sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
+
+        const onMembershipsChanged = jest.fn();
+        sess.on(MatrixRTCSessionEvent.MembershipsChanged, onMembershipsChanged);
+        sess.onMembershipUpdate();
+
+        expect(onMembershipsChanged).not.toHaveBeenCalled();
+    });
+
+    it("Emits on membership changes", () => {
+        const mockRoom = makeMockRoom([membershipTemplate]);
+        sess = MatrixRTCSession.roomSessionForRoom(client, mockRoom);
+
+        const onMembershipsChanged = jest.fn();
+        sess.on(MatrixRTCSessionEvent.MembershipsChanged, onMembershipsChanged);
+
+        mockRoom.getLiveTimeline().getState = jest
+            .fn()
+            .mockReturnValue(makeMockRoomState([], mockRoom.roomId, undefined));
+        sess.onMembershipUpdate();
+
+        expect(onMembershipsChanged).toHaveBeenCalled();
     });
 
     it("emits an event at the time a membership event expires", () => {
@@ -409,4 +593,54 @@ describe("MatrixRTCSession", () => {
             "@alice:example.org",
         );
     });
+
+    it("collects keys from encryption events", () => {
+        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"),
+        } as unknown as MatrixEvent);
+
+        const bobKeys = sess.getKeysForParticipant("@bob:example.org", "bobsphone")!;
+        expect(bobKeys).toHaveLength(1);
+        expect(bobKeys[0]).toEqual(Buffer.from("this is the key", "utf-8"));
+    });
+
+    it("collects keys at non-zero indices", () => {
+        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: 4,
+                        key: "dGhpcyBpcyB0aGUga2V5",
+                    },
+                ],
+            }),
+            getSender: jest.fn().mockReturnValue("@bob:example.org"),
+        } as unknown as MatrixEvent);
+
+        const bobKeys = sess.getKeysForParticipant("@bob:example.org", "bobsphone")!;
+        expect(bobKeys).toHaveLength(5);
+        expect(bobKeys[0]).toBeFalsy();
+        expect(bobKeys[1]).toBeFalsy();
+        expect(bobKeys[2]).toBeFalsy();
+        expect(bobKeys[3]).toBeFalsy();
+        expect(bobKeys[4]).toEqual(Buffer.from("this is the key", "utf-8"));
+    });
 });

spec/unit/matrixrtc/MatrixRTCSessionManager.spec.ts

@@ -14,7 +14,15 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { ClientEvent, EventTimeline, MatrixClient } from "../../../src";
+import {
+    ClientEvent,
+    EventTimeline,
+    EventType,
+    IRoomTimelineData,
+    MatrixClient,
+    MatrixEvent,
+    RoomEvent,
+} from "../../../src";
 import { RoomStateEvent } from "../../../src/models/room-state";
 import { CallMembershipData } from "../../../src/matrixrtc/CallMembership";
 import { MatrixRTCSessionManagerEvents } from "../../../src/matrixrtc/MatrixRTCSessionManager";
@@ -78,4 +86,26 @@ describe("MatrixRTCSessionManager", () => {
 
         expect(onEnded).toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
     });
+
+    it("Calls onCallEncryption on encryption keys event", () => {
+        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;
+
+        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"),
+            sender: {
+                userId: "@mock:user.example",
+            },
+        } as unknown as MatrixEvent;
+        client.emit(RoomEvent.Timeline, timelineEvent, undefined, undefined, false, {} as IRoomTimelineData);
+        expect(onCallEncryptionMock).toHaveBeenCalled();
+    });
 });

spec/unit/matrixrtc/mocks.ts

@@ -31,7 +31,11 @@ export function makeMockRoom(
     } as unknown as Room;
 }
 
-function makeMockRoomState(memberships: CallMembershipData[], roomId: string, getLocalAge: (() => number) | undefined) {
+export function makeMockRoomState(
+    memberships: CallMembershipData[],
+    roomId: string,
+    getLocalAge: (() => number) | undefined,
+) {
     return {
         getStateEvents: (_: string, stateKey: string) => {
             const event = mockRTCEvent(memberships, roomId, getLocalAge);