Element-R: pass device list change notifications into rust crypto-sdk (#3254)

Author: florianduros

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

@@ -662,13 +662,17 @@ describe("SlidingSyncSdk", () => {
         });
 
         it("can update device lists", () => {
+            client!.crypto!.processDeviceLists = jest.fn();
             ext.onResponse({
                 device_lists: {
                     changed: ["@alice:localhost"],
                     left: ["@bob:localhost"],
                 },
             });
-            // TODO: more assertions?
+            expect(client!.crypto!.processDeviceLists).toHaveBeenCalledWith({
+                changed: ["@alice:localhost"],
+                left: ["@bob:localhost"],
+            });
         });
 
         it("can update OTK counts and unused fallback keys", () => {

src/common-crypto/CryptoBackend.ts

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import type { IToDeviceEvent } from "../sync-accumulator";
+import type { IDeviceLists, IToDeviceEvent } from "../sync-accumulator";
 import { MatrixEvent } from "../models/event";
 import { Room } from "../models/room";
 import { CryptoApi } from "../crypto-api";
@@ -113,6 +113,14 @@ export interface SyncCryptoCallbacks {
      */
     processKeyCounts(oneTimeKeysCounts?: Record<string, number>, unusedFallbackKeys?: string[]): Promise<void>;
 
+    /**
+     * Handle the notification from /sync that device lists have
+     * been changed.
+     *
+     * @param deviceLists - device_lists field from /sync
+     */
+    processDeviceLists(deviceLists: IDeviceLists): Promise<void>;
+
     /**
      * Called by the /sync loop whenever an m.room.encryption event is received.
      *

src/crypto/index.ts

@@ -71,7 +71,7 @@ import { CryptoStore } from "./store/base";
 import { IVerificationChannel } from "./verification/request/Channel";
 import { TypedEventEmitter } from "../models/typed-event-emitter";
 import { IContent } from "../models/event";
-import { ISyncResponse, IToDeviceEvent } from "../sync-accumulator";
+import { IDeviceLists, ISyncResponse, IToDeviceEvent } from "../sync-accumulator";
 import { ISignatures } from "../@types/signed";
 import { IMessage } from "./algorithms/olm";
 import { CryptoBackend, OnSyncCompletedData } from "../common-crypto/CryptoBackend";
@@ -2893,21 +2893,12 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
     }
 
     /**
-     * Handle the notification from /sync or /keys/changes that device lists have
+     * Handle the notification from /sync that device lists have
      * been changed.
      *
-     * @param syncData - Object containing sync tokens associated with this sync
-     * @param syncDeviceLists - device_lists field from /sync, or response from
-     * /keys/changes
+     * @param deviceLists - device_lists field from /sync
      */
-    public async handleDeviceListChanges(
-        syncData: ISyncStateData,
-        syncDeviceLists: Required<ISyncResponse>["device_lists"],
-    ): Promise<void> {
-        // Initial syncs don't have device change lists. We'll either get the complete list
-        // of changes for the interval or will have invalidated everything in willProcessSync
-        if (!syncData.oldSyncToken) return;
-
+    public async processDeviceLists(deviceLists: IDeviceLists): Promise<void> {
         // Here, we're relying on the fact that we only ever save the sync data after
         // sucessfully saving the device list data, so we're guaranteed that the device
         // list store is at least as fresh as the sync token from the sync store, ie.
@@ -2916,7 +2907,7 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
         // If we didn't make this assumption, we'd have to use the /keys/changes API
         // to get key changes between the sync token in the device list and the 'old'
         // sync token used here to make sure we didn't miss any.
-        await this.evalDeviceListChanges(syncDeviceLists);
+        await this.evalDeviceListChanges(deviceLists);
     }
 
     /**

src/rust-crypto/rust-crypto.ts

@@ -17,7 +17,7 @@ limitations under the License.
 import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-js";
 
 import type { IEventDecryptionResult, IMegolmSessionData } from "../@types/crypto";
-import type { IToDeviceEvent } from "../sync-accumulator";
+import type { IDeviceLists, IToDeviceEvent } from "../sync-accumulator";
 import type { IEncryptedEventInfo } from "../crypto/api";
 import { MatrixEvent } from "../models/event";
 import { Room } from "../models/room";
@@ -176,20 +176,23 @@ export class RustCrypto implements CryptoBackend {
      * @param events - the received to-device messages
      * @param oneTimeKeysCounts - the received one time key counts
      * @param unusedFallbackKeys - the received unused fallback keys
+     * @param devices - the received device list updates
      * @returns A list of preprocessed to-device messages.
      */
     private async receiveSyncChanges({
         events,
         oneTimeKeysCounts = new Map<string, number>(),
         unusedFallbackKeys = new Set<string>(),
+        devices = new RustSdkCryptoJs.DeviceLists(),
     }: {
         events?: IToDeviceEvent[];
         oneTimeKeysCounts?: Map<string, number>;
         unusedFallbackKeys?: Set<string>;
+        devices?: RustSdkCryptoJs.DeviceLists;
     }): Promise<IToDeviceEvent[]> {
         const result = await this.olmMachine.receiveSyncChanges(
             events ? JSON.stringify(events) : "[]",
-            new RustSdkCryptoJs.DeviceLists(),
+            devices,
             oneTimeKeysCounts,
             unusedFallbackKeys,
         );
@@ -229,6 +232,16 @@ export class RustCrypto implements CryptoBackend {
         }
     }
 
+    /** called by the sync loop to process the notification that device lists have
+     * been changed.
+     *
+     * @param deviceLists - device_lists field from /sync
+     */
+    public async processDeviceLists(deviceLists: IDeviceLists): Promise<void> {
+        const devices = new RustSdkCryptoJs.DeviceLists(deviceLists.changed, deviceLists.left);
+        await this.receiveSyncChanges({ devices });
+    }
+
     /** called by the sync loop on m.room.encrypted events
      *
      * @param room - in which the event was received

src/sliding-sync-sdk.ts

@@ -85,13 +85,8 @@ class ExtensionE2EE implements Extension<ExtensionE2EERequest, ExtensionE2EEResp
 
     public async onResponse(data: ExtensionE2EEResponse): Promise<void> {
         // Handle device list updates
-        if (data["device_lists"]) {
-            await this.crypto.handleDeviceListChanges(
-                {
-                    oldSyncToken: "yep", // XXX need to do this so the device list changes get processed :(
-                },
-                data["device_lists"],
-            );
+        if (data.device_lists) {
+            await this.crypto.processDeviceLists(data.device_lists);
         }
 
         // Handle one_time_keys_count and unused_fallback_key_types

src/sync-accumulator.ts

@@ -132,7 +132,7 @@ interface IToDevice {
     events: IToDeviceEvent[];
 }
 
-interface IDeviceLists {
+export interface IDeviceLists {
     changed?: string[];
     left?: string[];
 }

src/sync.ts

@@ -1515,8 +1515,8 @@ export class SyncApi {
 
         // Handle device list updates
         if (data.device_lists) {
-            if (this.syncOpts.crypto) {
-                await this.syncOpts.crypto.handleDeviceListChanges(syncEventData, data.device_lists);
+            if (this.syncOpts.cryptoCallbacks) {
+                await this.syncOpts.cryptoCallbacks.processDeviceLists(data.device_lists);
             } else {
                 // FIXME if we *don't* have a crypto module, we still need to
                 // invalidate the device lists. But that would require a