Element-R: Implement VerificationRequest.accept (#3526)

* Pass `supportedVerificationMethods` into `VerificationRequest`

... so that the application can later call `accept()` and we know what to send.

* Implement `VerificationRequest.accept`

* Implement `VerificationRequest.declining`

* Update src/rust-crypto/verification.ts

spec/integ/crypto/verification.spec.ts

@@ -541,24 +541,18 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
     });
 
     describe("Incoming verification from another device", () => {
-        beforeEach(() => {
+        beforeEach(async () => {
             e2eKeyResponder.addDeviceKeys(TEST_USER_ID, TEST_DEVICE_ID, SIGNED_TEST_DEVICE_DATA);
-        });
 
-        oldBackendOnly("Incoming verification: can accept", async () => {
             aliceClient = await startTestClient();
+            await waitForDeviceList();
+        });
+
+        it("Incoming verification: can accept", async () => {
             const TRANSACTION_ID = "abcd";
 
             // Initiate the request by sending a to-device message
-            returnToDeviceMessageFromSync({
-                type: "m.key.verification.request",
-                content: {
-                    from_device: TEST_DEVICE_ID,
-                    methods: ["m.sas.v1"],
-                    transaction_id: TRANSACTION_ID,
-                    timestamp: Date.now() - 1000,
-                },
-            });
+            returnToDeviceMessageFromSync(buildRequestMessage(TRANSACTION_ID));
             const request: VerificationRequest = await emitPromise(
                 aliceClient,
                 CryptoEvent.VerificationRequestReceived,
@@ -585,6 +579,31 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
             expect(toDeviceMessage.from_device).toEqual(aliceClient.deviceId);
             expect(toDeviceMessage.transaction_id).toEqual(TRANSACTION_ID);
         });
+
+        it("Incoming verification: can refuse", async () => {
+            const TRANSACTION_ID = "abcd";
+
+            // Initiate the request by sending a to-device message
+            returnToDeviceMessageFromSync(buildRequestMessage(TRANSACTION_ID));
+            const request: VerificationRequest = await emitPromise(
+                aliceClient,
+                CryptoEvent.VerificationRequestReceived,
+            );
+            expect(request.transactionId).toEqual(TRANSACTION_ID);
+
+            // Alice declines, by sending a cancellation
+            const sendToDevicePromise = expectSendToDeviceMessage("m.key.verification.cancel");
+            const cancelPromise = request.cancel();
+            expect(canAcceptVerificationRequest(request)).toBe(false);
+            expect(request.accepting).toBe(false);
+            expect(request.declining).toBe(true);
+            await cancelPromise;
+            const requestBody = await sendToDevicePromise;
+            expect(request.phase).toEqual(VerificationPhase.Cancelled);
+
+            const toDeviceMessage = requestBody.messages[TEST_USER_ID][TEST_DEVICE_ID];
+            expect(toDeviceMessage.transaction_id).toEqual(TRANSACTION_ID);
+        });
     });
 
     async function startTestClient(opts: Partial<ICreateClientOpts> = {}): Promise<MatrixClient> {
@@ -668,6 +687,19 @@ function encodeUnpaddedBase64(uint8Array: ArrayBuffer | Uint8Array): string {
     return Buffer.from(uint8Array).toString("base64").replace(/=+$/g, "");
 }
 
+/** build an m.key.verification.request to-device message originating from the dummy device */
+function buildRequestMessage(transactionId: string): { type: string; content: object } {
+    return {
+        type: "m.key.verification.request",
+        content: {
+            from_device: TEST_DEVICE_ID,
+            methods: ["m.sas.v1"],
+            transaction_id: transactionId,
+            timestamp: Date.now() - 1000,
+        },
+    };
+}
+
 /** build an m.key.verification.ready to-device message originating from the dummy device */
 function buildReadyMessage(transactionId: string, methods: string[]): { type: string; content: object } {
     return {

spec/unit/rust-crypto/verification.spec.ts

@@ -32,7 +32,7 @@ describe("VerificationRequest", () => {
                 startSas: jest.fn(),
             } as unknown as Mocked<RustSdkCryptoJs.VerificationRequest>;
             mockedOutgoingRequestProcessor = {} as Mocked<OutgoingRequestProcessor>;
-            request = new RustVerificationRequest(mockedInner, mockedOutgoingRequestProcessor);
+            request = new RustVerificationRequest(mockedInner, mockedOutgoingRequestProcessor, undefined);
         });
 
         it("does not permit methods other than SAS", async () => {

src/rust-crypto/rust-crypto.ts

@@ -553,7 +553,14 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
         );
         return requests
             .filter((request) => request.roomId === undefined)
-            .map((request) => new RustVerificationRequest(request, this.outgoingRequestProcessor));
+            .map(
+                (request) =>
+                    new RustVerificationRequest(
+                        request,
+                        this.outgoingRequestProcessor,
+                        this.supportedVerificationMethods,
+                    ),
+            );
     }
 
     /**
@@ -600,7 +607,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
                 this.supportedVerificationMethods?.map(verificationMethodIdentifierToMethod),
             );
         await this.outgoingRequestProcessor.makeOutgoingRequest(outgoingRequest);
-        return new RustVerificationRequest(request, this.outgoingRequestProcessor);
+        return new RustVerificationRequest(request, this.outgoingRequestProcessor, this.supportedVerificationMethods);
     }
 
     /**
@@ -630,7 +637,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
                 this.supportedVerificationMethods?.map(verificationMethodIdentifierToMethod),
             );
         await this.outgoingRequestProcessor.makeOutgoingRequest(outgoingRequest);
-        return new RustVerificationRequest(request, this.outgoingRequestProcessor);
+        return new RustVerificationRequest(request, this.outgoingRequestProcessor, this.supportedVerificationMethods);
     }
 
     ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -784,7 +791,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
         if (request) {
             this.emit(
                 CryptoEvent.VerificationRequestReceived,
-                new RustVerificationRequest(request, this.outgoingRequestProcessor),
+                new RustVerificationRequest(request, this.outgoingRequestProcessor, this.supportedVerificationMethods),
             );
         }
     }

src/rust-crypto/verification.ts

@@ -38,11 +38,25 @@ export class RustVerificationRequest
     extends TypedEventEmitter<VerificationRequestEvent, VerificationRequestEventHandlerMap>
     implements VerificationRequest
 {
+    /** Are we in the process of sending an `m.key.verification.ready` event? */
+    private _accepting = false;
+
+    /** Are we in the process of sending an `m.key.verification.cancellation` event? */
+    private _cancelling = false;
+
     private _verifier: Verifier | undefined;
 
+    /**
+     * Construct a new RustVerificationRequest to wrap the rust-level `VerificationRequest`.
+     *
+     * @param inner - VerificationRequest from the Rust SDK
+     * @param outgoingRequestProcessor - `OutgoingRequestProcessor` to use for making outgoing HTTP requests
+     * @param supportedVerificationMethods - Verification methods to use when `accept()` is called
+     */
     public constructor(
         private readonly inner: RustSdkCryptoJs.VerificationRequest,
         private readonly outgoingRequestProcessor: OutgoingRequestProcessor,
+        private readonly supportedVerificationMethods: string[] | undefined,
     ) {
         super();
 
@@ -113,7 +127,9 @@ export class RustVerificationRequest
             case RustSdkCryptoJs.VerificationRequestPhase.Requested:
                 return VerificationPhase.Requested;
             case RustSdkCryptoJs.VerificationRequestPhase.Ready:
-                return VerificationPhase.Ready;
+                // if we're still sending the `m.key.verification.ready`, that counts as "Requested" in the js-sdk's
+                // parlance.
+                return this._accepting ? VerificationPhase.Requested : VerificationPhase.Ready;
             case RustSdkCryptoJs.VerificationRequestPhase.Transitioned:
                 return VerificationPhase.Started;
             case RustSdkCryptoJs.VerificationRequestPhase.Done:
@@ -137,15 +153,15 @@ export class RustVerificationRequest
      * the remote echo which causes a transition to {@link VerificationPhase.Ready}.
      */
     public get accepting(): boolean {
-        throw new Error("not implemented");
+        return this._accepting;
     }
 
     /**
      * True if we have started the process of sending an `m.key.verification.cancel` (but have not necessarily received
      * the remote echo which causes a transition to {@link VerificationPhase.Cancelled}).
      */
     public get declining(): boolean {
-        throw new Error("not implemented");
+        return this._cancelling;
     }
 
     /**
@@ -198,8 +214,28 @@ export class RustVerificationRequest
      *
      * @returns Promise which resolves when the event has been sent.
      */
-    public accept(): Promise<void> {
-        throw new Error("not implemented");
+    public async accept(): Promise<void> {
+        if (this.inner.phase() !== RustSdkCryptoJs.VerificationRequestPhase.Requested || this._accepting) {
+            throw new Error(`Cannot accept a verification request in phase ${this.phase}`);
+        }
+
+        this._accepting = true;
+        try {
+            const req: undefined | OutgoingRequest =
+                this.supportedVerificationMethods === undefined
+                    ? this.inner.accept()
+                    : this.inner.acceptWithMethods(
+                          this.supportedVerificationMethods.map(verificationMethodIdentifierToMethod),
+                      );
+            if (req) {
+                await this.outgoingRequestProcessor.makeOutgoingRequest(req);
+            }
+        } finally {
+            this._accepting = false;
+        }
+
+        // phase may have changed, so emit a 'change' event
+        this.emit(VerificationRequestEvent.Change);
     }
 
     /**
@@ -211,9 +247,19 @@ export class RustVerificationRequest
      * @returns Promise which resolves when the event has been sent.
      */
     public async cancel(params?: { reason?: string; code?: string }): Promise<void> {
-        const req: undefined | OutgoingRequest = this.inner.cancel();
-        if (req) {
-            await this.outgoingRequestProcessor.makeOutgoingRequest(req);
+        if (this._cancelling) {
+            // already cancelling; do nothing
+            return;
+        }
+
+        this._cancelling = true;
+        try {
+            const req: undefined | OutgoingRequest = this.inner.cancel();
+            if (req) {
+                await this.outgoingRequestProcessor.makeOutgoingRequest(req);
+            }
+        } finally {
+            this._cancelling = false;
         }
     }
 

yarn.lock

@@ -1427,9 +1427,9 @@
     lodash "^4.17.21"
 
 "@matrix-org/matrix-sdk-crypto-js@^0.1.0-alpha.11":
-  version "0.1.0-alpha.11"
-  resolved "https://registry.yarnpkg.com/@matrix-org/matrix-sdk-crypto-js/-/matrix-sdk-crypto-js-0.1.0-alpha.11.tgz#24d705318c3159ef7dbe43bca464ac2bdd11e45d"
-  integrity sha512-HD3rskPkqrUUSaKzGLg97k/bN+OZrkcX7ODB/pNBs/jqq+/A0wDKqsszJotzFwsQcDPpWn78BmMyvBo4tLxKjw==
+  version "0.1.0"
+  resolved "https://registry.yarnpkg.com/@matrix-org/matrix-sdk-crypto-js/-/matrix-sdk-crypto-js-0.1.0.tgz#766580036d4df12120ded223e13b5640e77db136"
+  integrity sha512-ra/bcFdleC1iRNms2I96UXA0NvQYWpMsHrV5EfJRS7qV1PtnQNvgsvMfjMbkx8QT2ErEmIhsvB5fPCpfp8BSuw==
 
 "@matrix-org/olm@https://gitlab.matrix.org/api/v4/projects/27/packages/npm/@matrix-org/olm/-/@matrix-org/olm-3.2.14.tgz":
   version "3.2.14"