Make Jitsi widgets in video rooms immutable (#8244)

* Make Jitsi widgets in video rooms immutable

* Test video room creation

src/createRoom.ts

@@ -126,11 +126,14 @@ export default async function createRoom(opts: IOpts): Promise<string | null> {
             [RoomCreateTypeField]: opts.roomType,
         };
 
-        // In video rooms, allow all users to send video member updates
+        // Video rooms require custom power levels
         if (opts.roomType === RoomType.ElementVideo) {
             createOpts.power_level_content_override = {
                 events: {
+                    // Allow all users to send video member updates
                     [VIDEO_CHANNEL_MEMBER]: 0,
+                    // Make widgets immutable, even to admins
+                    "im.vector.modular.widgets": 200,
                     // Annoyingly, we have to reiterate all the defaults here
                     [EventType.RoomName]: 50,
                     [EventType.RoomAvatar]: 50,
@@ -141,6 +144,10 @@ export default async function createRoom(opts: IOpts): Promise<string | null> {
                     [EventType.RoomServerAcl]: 100,
                     [EventType.RoomEncryption]: 100,
                 },
+                users: {
+                    // Temporarily give ourselves the power to set up a widget
+                    [client.getUserId()]: 200,
+                },
             };
         }
     }
@@ -259,10 +266,15 @@ export default async function createRoom(opts: IOpts): Promise<string | null> {
         if (opts.parentSpace) {
             return SpaceStore.instance.addRoomToSpace(opts.parentSpace, roomId, [client.getDomain()], opts.suggested);
         }
-    }).then(() => {
-        // Set up video rooms with a Jitsi widget
+    }).then(async () => {
         if (opts.roomType === RoomType.ElementVideo) {
-            return addVideoChannel(roomId, createOpts.name);
+            // Set up video rooms with a Jitsi widget
+            await addVideoChannel(roomId, createOpts.name);
+
+            // Reset our power level back to admin so that the widget becomes immutable
+            const room = client.getRoom(roomId);
+            const plEvent = room?.currentState.getStateEvents(EventType.RoomPowerLevels, "");
+            await client.setPowerLevel(roomId, client.getUserId(), 100, plEvent);
         }
     }).then(function() {
         // NB createRoom doesn't block on the client seeing the echo that the

test/createRoom-test.ts

@@ -0,0 +1,100 @@
+/*
+Copyright 2022 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 { mocked } from "jest-mock";
+import { MatrixClient } from "matrix-js-sdk/src/matrix";
+import { IDevice } from "matrix-js-sdk/src/crypto/deviceinfo";
+import { RoomType } from "matrix-js-sdk/src/@types/event";
+
+import { stubClient, setupAsyncStoreWithClient } from "./test-utils";
+import { MatrixClientPeg } from "../src/MatrixClientPeg";
+import WidgetStore from "../src/stores/WidgetStore";
+import WidgetUtils from "../src/utils/WidgetUtils";
+import { VIDEO_CHANNEL, VIDEO_CHANNEL_MEMBER } from "../src/utils/VideoChannelUtils";
+import createRoom, { canEncryptToAllUsers } from '../src/createRoom';
+
+describe("createRoom", () => {
+    let client: MatrixClient;
+    beforeEach(() => {
+        stubClient();
+        client = MatrixClientPeg.get();
+    });
+
+    it("sets up video rooms correctly", async () => {
+        setupAsyncStoreWithClient(WidgetStore.instance, client);
+        jest.spyOn(WidgetUtils, "waitForRoomWidget").mockResolvedValue();
+
+        const userId = client.getUserId();
+        const roomId = await createRoom({ roomType: RoomType.ElementVideo });
+
+        const [[{
+            power_level_content_override: {
+                users: {
+                    [userId]: userPower,
+                },
+                events: {
+                    "im.vector.modular.widgets": widgetPower,
+                    [VIDEO_CHANNEL_MEMBER]: videoMemberPower,
+                },
+            },
+        }]] = mocked(client.createRoom).mock.calls as any;
+        const [[widgetRoomId, widgetStateKey, , widgetId]] = mocked(client.sendStateEvent).mock.calls;
+
+        // We should have had enough power to be able to set up the Jitsi widget
+        expect(userPower).toBeGreaterThanOrEqual(widgetPower);
+        // and should have actually set it up
+        expect(widgetRoomId).toEqual(roomId);
+        expect(widgetStateKey).toEqual("im.vector.modular.widgets");
+        expect(widgetId).toEqual(VIDEO_CHANNEL);
+
+        // All members should be able to update their connected devices
+        expect(videoMemberPower).toEqual(0);
+        // Jitsi widget should be immutable for admins
+        expect(widgetPower).toBeGreaterThan(100);
+        // and we should have been reset back to admin
+        expect(client.setPowerLevel).toHaveBeenCalledWith(roomId, userId, 100, undefined);
+    });
+});
+
+describe("canEncryptToAllUsers", () => {
+    const trueUser = {
+        "@goodUser:localhost": {
+            "DEV1": {} as unknown as IDevice,
+            "DEV2": {} as unknown as IDevice,
+        },
+    };
+    const falseUser = {
+        "@badUser:localhost": {},
+    };
+
+    let client: MatrixClient;
+    beforeEach(() => {
+        stubClient();
+        client = MatrixClientPeg.get();
+    });
+
+    it("returns true if all devices have crypto", async () => {
+        mocked(client.downloadKeys).mockResolvedValue(trueUser);
+        const response = await canEncryptToAllUsers(client, ["@goodUser:localhost"]);
+        expect(response).toBe(true);
+    });
+
+    it("returns false if not all users have crypto", async () => {
+        mocked(client.downloadKeys).mockResolvedValue({ ...trueUser, ...falseUser });
+        const response = await canEncryptToAllUsers(client, ["@goodUser:localhost", "@badUser:localhost"]);
+        expect(response).toBe(false);
+    });
+});

test/test-utils/test-utils.ts

@@ -108,6 +108,8 @@ export function createTestClient(): MatrixClient {
         getRoomHierarchy: jest.fn().mockReturnValue({
             rooms: [],
         }),
+        createRoom: jest.fn().mockResolvedValue({ room_id: "!1:example.org" }),
+        setPowerLevel: jest.fn().mockResolvedValue(undefined),
 
         // Used by various internal bits we aren't concerned with (yet)
         sessionStore: {
@@ -135,6 +137,7 @@ export function createTestClient(): MatrixClient {
         setPushRuleActions: jest.fn().mockResolvedValue(undefined),
         relations: jest.fn().mockRejectedValue(undefined),
         isCryptoEnabled: jest.fn().mockReturnValue(false),
+        downloadKeys: jest.fn(),
         fetchRoomEvent: jest.fn(),
     } as unknown as MatrixClient;
 }