Cover identity matching and delegation across transport shapes

playwright/url-transport.spec.ts

@@ -116,6 +116,12 @@ for (const { hostShape, guestShape, mode, hostFlows, guestFlows } of cases) {
     for (const request of [...hostRequests, ...guestRequests]) {
       expect(request.status).toBe(200);
       if (request.flow === "cs-api") expect(request.sfuUrl).toBe(sfuUrl);
+      // Clients predating MSC4195 match a publisher by the legacy identity,
+      // which only the JWT service's legacy endpoint assigns. The other flows
+      // hash it.
+      expect(request.identity).toMatch(
+        request.flow === "service-legacy" ? legacyIdentity : hashedIdentity,
+      );
     }
   });
 }
@@ -185,15 +191,26 @@ test("Publisher shows an error when the homeserver lacks MSC4195", async ({
   ).toBeVisible();
 });
 
-test("Delayed leave event delegated to a url transport gets sent on disconnect", async ({
+/**
+ * Delegation follows the flow that authenticated the publisher: the homeserver
+ * for a `url`-only transport, the JWT service wherever there is one.
+ */
+const delegationCases: { shape: Shape; via: Delegation["via"] }[] = [
+  { shape: "url", via: "homeserver" },
+  { shape: "legacy", via: "service" },
+  { shape: "both", via: "service" },
+];
+
+for (const { shape, via } of delegationCases) {
+  test(`Delayed leave event delegated through the ${via} for a ${shape} transport gets sent on disconnect`, async ({
     browser,
     page,
     browserName,
-}) => {
+  }) => {
     skipOnFirefox(browserName);
 
     // The host starts the call.
-  await advertiseTransport(page, shapes.url);
+    await advertiseTransport(page, shapes[shape]);
     await page.goto("/");
     await SpaHelpers.createCall(page, "Androl", "HelloCall", true);
     const inviteLink = await SpaHelpers.getCallInviteLink(page);
@@ -201,7 +218,7 @@ test("Delayed leave event delegated to a url transport gets sent on disconnect",
     // The guest joins.
     const guestContext = await browser.newContext({ reducedMotion: "reduce" });
     const guestPage = await guestContext.newPage();
-  await advertiseTransport(guestPage, shapes.url);
+    await advertiseTransport(guestPage, shapes[shape]);
     const delayedLeave = recordDelayedLeave(guestPage);
     const delegations = recordDelegations(guestPage);
     await SpaHelpers.joinCallFromInviteLink(guestPage, inviteLink, "Pevara");
@@ -210,17 +227,27 @@ test("Delayed leave event delegated to a url transport gets sent on disconnect",
     await SpaHelpers.expectVideoTilesCount(page, 2);
     await SpaHelpers.expectVideoTilesCount(guestPage, 2);
 
-  // The guest handed its delayed leave to the homeserver, after probing it for
+    // The guest handed its delayed leave over, after probing for delegation
-  // delegation support with bodiless requests.
+    // support with bodiless requests, which count as supported unless they
+    // 404. The homeserver is always probed; the JWT service only when there
+    // is one.
     await expect
       .poll(() => delegations.at(-1))
-    .toEqual({ status: 200, sfuUrl, delayId: delayedLeave.delayId });
+      .toEqual({
+        via,
+        status: 200,
+        delayId: delayedLeave.delayId,
+        ...(via === "homeserver" && { sfuUrl }),
+      });
     const probes = delegations.slice(0, -1);
-  expect(probes.length).toBeGreaterThan(0);
+    expect(probes.some((probe) => probe.via === via)).toBe(true);
-  for (const probe of probes) expect(probe).toEqual({ status: 401 });
+    for (const probe of probes) {
+      expect(probe.status).toBeGreaterThanOrEqual(400);
+      expect(probe.status).not.toBe(404);
+    }
 
-  // The delay is long enough that a leave within the window below cannot come
+    // The delay is long enough that a leave within the window below cannot
-  // from the delayed event expiring on its own.
+    // come from the delayed event expiring on its own.
     expect(delayedLeave.delayMs).toBeGreaterThan(60_000);
 
     // The guest drops without leaving.
@@ -230,7 +257,8 @@ test("Delayed leave event delegated to a url transport gets sent on disconnect",
     await expect(page.getByTestId("videoTile")).toHaveCount(1, {
       timeout: 30_000,
     });
-});
+  });
+}
 
 test("Subscribers get tokens for a remote homeserver's SFU over federation", async ({
   browser,
@@ -365,29 +393,43 @@ function recordDelayedLeave(page: Page): DelayedLeave {
 
 /** A recorded delegation request for a delayed leave event. */
 interface Delegation {
+  /** Who was asked to send the leave event on the guest's behalf. */
+  via: "homeserver" | "service";
   status: number;
   sfuUrl?: string;
   delayId?: string;
 }
 
-/** Records requests to the MSC4195 `delegate_delayed_leave` endpoint. */
+/**
+ * Records requests that delegate a delayed leave event, or probe for support:
+ * the MSC4195 `delegate_delayed_leave` endpoint of the homeserver, and the JWT
+ * service's `delegate_delayed_leave` probe and `/sfu/get` with delay fields.
+ */
 function recordDelegations(page: Page): Delegation[] {
   const delegations: Delegation[] = [];
   page.on("response", (response) => {
     const request = response.request();
-    if (
+    if (request.method() !== "POST") return;
-      request.method() !== "POST" ||
+    const url = request.url();
-      !request.url().endsWith("/rtc/livekit/delegate_delayed_leave")
-    )
-      return;
     const body = request.postDataJSON() as {
-      url: string;
+      url?: string;
-      delay_id: string;
+      delay_id?: string;
     } | null;
+    if (url.endsWith("/rtc/livekit/delegate_delayed_leave")) {
       delegations.push({
+        via: "homeserver",
         status: response.status(),
         ...(body && { sfuUrl: body.url, delayId: body.delay_id }),
       });
+    } else if (url.endsWith("/livekit/jwt/delegate_delayed_leave")) {
+      delegations.push({ via: "service", status: response.status() });
+    } else if (url.endsWith("/livekit/jwt/sfu/get") && body?.delay_id) {
+      delegations.push({
+        via: "service",
+        status: response.status(),
+        delayId: body.delay_id,
+      });
+    }
   });
   return delegations;
 }
@@ -398,26 +440,54 @@ interface AuthRequest {
   status: number;
   /** The SFU a request to the MSC4195 `get_token` endpoint asked for. */
   sfuUrl?: string;
+  /** The participant identity the issued token carries. */
+  identity?: string;
 }
 
-/** Records token requests. */
+/** The legacy `<user_id>:<device_id>` participant identity. */
+const legacyIdentity = /^@[^:]+:[^:]+:[A-Z]+$/;
+/** A hashed participant identity: unpadded base64 of a SHA-256. */
+const hashedIdentity = /^[A-Za-z0-9+/]{43}$/;
+
+/** Reads the subject of a JWT without verifying it. */
+function jwtSubject(jwt: string): string {
+  const [, payload] = jwt.split(".");
+  return (
+    JSON.parse(Buffer.from(payload, "base64url").toString()) as {
+      sub: string;
+    }
+  ).sub;
+}
+
+/** Records token requests, including the identity each token carries. */
 function recordAuthRequests(page: Page): AuthRequest[] {
   const requests: AuthRequest[] = [];
   page.on("response", (response) => {
     const request = response.request();
     if (request.method() !== "POST") return;
     const url = request.url();
+    let entry: AuthRequest;
     if (url.endsWith("/rtc/livekit/get_token")) {
-      requests.push({
+      entry = {
         flow: "cs-api",
         status: response.status(),
         sfuUrl: (request.postDataJSON() as { url: string }).url,
-      });
+      };
     } else if (url.endsWith("/livekit/jwt/sfu/get")) {
-      requests.push({ flow: "service-legacy", status: response.status() });
+      entry = { flow: "service-legacy", status: response.status() };
     } else if (url.endsWith("/livekit/jwt/get_token")) {
-      requests.push({ flow: "service-default", status: response.status() });
+      entry = { flow: "service-default", status: response.status() };
+    } else {
+      return;
     }
+    requests.push(entry);
+    if (entry.status !== 200) return;
+    response
+      .json()
+      .then((body: { jwt: string }) => {
+        entry.identity = jwtSubject(body.jwt);
+      })
+      .catch(() => {});
   });
   return requests;
 }

src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.test.ts

@@ -170,6 +170,90 @@ test("should signal participant on a connection that is publishing", async () =>
   );
 });
 
+// A member advertising both a `url` and a `livekit_service_url` may have
+// authenticated through either flow, so it has two candidate identities.
+const bothTransport: UnstableLivekitTransport = {
+  type: "livekit",
+  url: "wss://sfu.example.org",
+  livekit_service_url: "https://lk.example.org",
+};
+const bobLegacyId = fallbackMemberId("@bob:example.org", "DEV000");
+const bobHashedId = "2qkXfWz1S7jQmU0bJ6yN8aVtR3pLcDgHe9oZxKwMiA4";
+const bobWithBothIdentities = mockRtcMembership("@bob:example.org", "DEV000", {
+  fociPreferred: [bothTransport],
+  backendIdentities: [bobHashedId, bobLegacyId],
+});
+
+test.each([
+  ["legacy", bobLegacyId],
+  ["hashed", bobHashedId],
+])(
+  "matches a member with two candidate identities publishing under the %s one",
+  async (_name, identity) => {
+    const { memberships$, membershipsWithTransport$ } =
+      createEpochedMemberships$(constant([bobWithBothIdentities]));
+
+    const connection = {
+      transport: bothTransport,
+      serverName: "example.org",
+    } as unknown as Connection;
+    const dataWithPublisher = new ConnectionMap();
+    dataWithPublisher.add(connection, [mockRemoteParticipant({ identity })]);
+
+    const remoteMatrixLivekitMembers$ = createRemoteMatrixLivekitMembers$({
+      scope: testScope,
+      membershipsWithTransport$: testScope.behavior(membershipsWithTransport$),
+      connectionMap$: testScope.behavior(
+        epochMeWith$(memberships$, constant(dataWithPublisher)),
+      ),
+      localUser: localRtcMember,
+    });
+
+    await flushPromises();
+    expect(remoteMatrixLivekitMembers$.value.value).toSatisfy(
+      (data: RemoteMatrixLivekitMember[]) => {
+        expect(data.length).toEqual(1);
+        expect(data[0].participant.value$.value?.identity).toEqual(identity);
+        expect(data[0].connection$.value).toBe(connection);
+        return true;
+      },
+    );
+  },
+);
+
+test("does not match a member with two candidate identities to anyone else", async () => {
+  const { memberships$, membershipsWithTransport$ } = createEpochedMemberships$(
+    constant([bobWithBothIdentities]),
+  );
+
+  const connection = {
+    transport: bothTransport,
+    serverName: "example.org",
+  } as unknown as Connection;
+  const dataWithStranger = new ConnectionMap();
+  dataWithStranger.add(connection, [
+    mockRemoteParticipant({ identity: "@stranger:example.org:DEV999" }),
+  ]);
+
+  const remoteMatrixLivekitMembers$ = createRemoteMatrixLivekitMembers$({
+    scope: testScope,
+    membershipsWithTransport$: testScope.behavior(membershipsWithTransport$),
+    connectionMap$: testScope.behavior(
+      epochMeWith$(memberships$, constant(dataWithStranger)),
+    ),
+    localUser: localRtcMember,
+  });
+
+  await flushPromises();
+  expect(remoteMatrixLivekitMembers$.value.value).toSatisfy(
+    (data: RemoteMatrixLivekitMember[]) => {
+      expect(data.length).toEqual(1);
+      expect(data[0].participant.value$.value).toBe(null);
+      return true;
+    },
+  );
+});
+
 test("should signal participant on a connection that is not publishing", async () => {
   const { memberships$, membershipsWithTransport$ } = createEpochedMemberships$(
     constant([bobMembership]),

src/utils/test.ts

@@ -224,6 +224,8 @@ export function mockRtcMembership(
   deviceId: string,
   customOverwrites?: {
     rtcBackendIdentity?: string;
+    /** Every identity the member may have in LiveKit, when more than one. */
+    backendIdentities?: string[];
     callId?: string;
     fociPreferred?: Transport[];
     focusActive?: LivekitFocusSelection;
@@ -263,7 +265,7 @@ export function mockRtcMembership(
   const cms = new CallMembership(
     event,
     CallMembership.membershipDataFromMatrixEvent(event),
-    [backendIdentity],
+    customOverwrites?.backendIdentities ?? [backendIdentity],
     backendIdentity,
   );
   vi.mocked(cms).getTransport = vi.fn().mockReturnValue(fociPreferred[0]);