Rust crypto: emit VerificationRequestReceived events (#3525)

src/rust-crypto/rust-crypto.ts

@@ -19,7 +19,7 @@ import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-js";
 import type { IEventDecryptionResult, IMegolmSessionData } from "../@types/crypto";
 import type { IDeviceLists, IToDeviceEvent } from "../sync-accumulator";
 import type { IEncryptedEventInfo } from "../crypto/api";
-import { MatrixEvent } from "../models/event";
+import { IContent, MatrixEvent } from "../models/event";
 import { Room } from "../models/room";
 import { RoomMember } from "../models/room-member";
 import { CryptoBackend, OnSyncCompletedData } from "../common-crypto/CryptoBackend";
@@ -32,15 +32,15 @@ import { KeyClaimManager } from "./KeyClaimManager";
 import { MapWithDefault } from "../utils";
 import {
     BootstrapCrossSigningOpts,
+    CreateSecretStorageOpts,
     CrossSigningKey,
     CrossSigningStatus,
+    CryptoCallbacks,
     DeviceVerificationStatus,
     GeneratedSecretStorageKey,
     ImportRoomKeyProgressData,
     ImportRoomKeysOpts,
     VerificationRequest,
-    CreateSecretStorageOpts,
-    CryptoCallbacks,
 } from "../crypto-api";
 import { deviceKeysToDeviceMap, rustDeviceToJsDevice } from "./device-converter";
 import { IDownloadKeyResult, IQueryKeysRequest } from "../client";
@@ -52,11 +52,14 @@ import { keyFromPassphrase } from "../crypto/key_passphrase";
 import { encodeRecoveryKey } from "../crypto/recoverykey";
 import { crypto } from "../crypto/crypto";
 import { RustVerificationRequest, verificationMethodIdentifierToMethod } from "./verification";
+import { EventType } from "../@types/event";
+import { CryptoEvent } from "../crypto";
+import { TypedEventEmitter } from "../models/typed-event-emitter";
 
 /**
  * An implementation of {@link CryptoBackend} using the Rust matrix-sdk-crypto.
  */
-export class RustCrypto implements CryptoBackend {
+export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEventMap> implements CryptoBackend {
     public globalErrorOnUnknownDevices = false;
     private _trustCrossSignedDevices = true;
 
@@ -97,6 +100,7 @@ export class RustCrypto implements CryptoBackend {
         /** Crypto callbacks provided by the application */
         private readonly cryptoCallbacks: CryptoCallbacks,
     ) {
+        super();
         this.outgoingRequestProcessor = new OutgoingRequestProcessor(olmMachine, http);
         this.keyClaimManager = new KeyClaimManager(olmMachine, this.outgoingRequestProcessor);
         this.eventDecryptor = new EventDecryptor(olmMachine);
@@ -670,10 +674,18 @@ export class RustCrypto implements CryptoBackend {
      * @param events - the received to-device messages
      * @returns A list of preprocessed to-device messages.
      */
-    public preprocessToDeviceMessages(events: IToDeviceEvent[]): Promise<IToDeviceEvent[]> {
+    public async preprocessToDeviceMessages(events: IToDeviceEvent[]): Promise<IToDeviceEvent[]> {
         // send the received to-device messages into receiveSyncChanges. We have no info on device-list changes,
         // one-time-keys, or fallback keys, so just pass empty data.
-        return this.receiveSyncChanges({ events });
+        const processed = await this.receiveSyncChanges({ events });
+
+        // look for interesting to-device messages
+        for (const message of processed) {
+            if (message.type === EventType.KeyVerificationRequest) {
+                this.onIncomingKeyVerificationRequest(message.sender, message.content);
+            }
+        }
+        return processed;
     }
 
     /** called by the sync loop to process one time key counts and unused fallback keys
@@ -751,6 +763,32 @@ export class RustCrypto implements CryptoBackend {
         this.outgoingRequestLoop();
     }
 
+    /**
+     * Handle an incoming m.key.verification request event
+     *
+     * @param sender - the sender of the event
+     * @param content - the content of the event
+     */
+    private onIncomingKeyVerificationRequest(sender: string, content: IContent): void {
+        const transactionId = content.transaction_id;
+        if (!transactionId || !sender) {
+            // not a valid request: ignore
+            return;
+        }
+
+        const request: RustSdkCryptoJs.VerificationRequest | undefined = this.olmMachine.getVerificationRequest(
+            new RustSdkCryptoJs.UserId(sender),
+            transactionId,
+        );
+
+        if (request) {
+            this.emit(
+                CryptoEvent.VerificationRequestReceived,
+                new RustVerificationRequest(request, this.outgoingRequestProcessor),
+            );
+        }
+    }
+
     ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     //
     // Other public functions
@@ -939,3 +977,12 @@ class EventDecryptor {
         }
     }
 }
+
+type RustCryptoEvents = CryptoEvent.VerificationRequestReceived;
+
+type RustCryptoEventMap = {
+    /**
+     * Fires when a key verification request is received.
+     */
+    [CryptoEvent.VerificationRequestReceived]: (request: VerificationRequest) => void;
+};