Add CryptoApi.encryptToDeviceMessages() and deprecate Crypto.encryptA…

…ndSendToDevices() (#4380)

* Add CryptoApi. encryptToDeviceMessages

Deprecate Crypto. encryptAndSendToDevices and MatrixClient. encryptAndSendToDevices

* Overload MatrixClient. encryptAndSendToDevices instead of deprecating

* Revert "Overload MatrixClient. encryptAndSendToDevices instead of deprecating"

This reverts commit 6a0d8e2.

* Feedback from code review

* Use temporary pre-release build of @matrix-org/matrix-sdk-crypto-wasm

* Deduplicate user IDs

* Test for RustCrypto implementation

* Use ensureSessionsForUsers()

* Encrypt to-device messages in parallel

* Use release version of matrix-sdk-crypto-wasm

* Upgrade matrix-sdk-crypto-wasm to v8

* Sync with develop

* Add test for olmlib CryptoApi

* Fix link

* Feedback from review

* Move libolm implementation to better place in file

* FIx doc

* Integration test

* Make sure test device is known to client

* Feedback from review

spec/integ/crypto/to-device-messages.spec.ts

@@ -0,0 +1,152 @@
+/*
+Copyright 2024 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 fetchMock from "fetch-mock-jest";
+import "fake-indexeddb/auto";
+import { IDBFactory } from "fake-indexeddb";
+
+import { CRYPTO_BACKENDS, getSyncResponse, InitCrypto, syncPromise } from "../../test-utils/test-utils";
+import { createClient, MatrixClient } from "../../../src";
+import * as testData from "../../test-utils/test-data";
+import { E2EKeyResponder } from "../../test-utils/E2EKeyResponder";
+import { SyncResponder } from "../../test-utils/SyncResponder";
+import { E2EKeyReceiver } from "../../test-utils/E2EKeyReceiver";
+
+afterEach(() => {
+    // reset fake-indexeddb after each test, to make sure we don't leak connections
+    // cf https://github.com/dumbmatter/fakeIndexedDB#wipingresetting-the-indexeddb-for-a-fresh-state
+    // eslint-disable-next-line no-global-assign
+    indexedDB = new IDBFactory();
+});
+
+/**
+ * Integration tests for to-device messages functionality.
+ *
+ * These tests work by intercepting HTTP requests via fetch-mock rather than mocking out bits of the client, so as
+ * to provide the most effective integration tests possible.
+ */
+describe.each(Object.entries(CRYPTO_BACKENDS))("to-device-messages (%s)", (backend: string, initCrypto: InitCrypto) => {
+    let aliceClient: MatrixClient;
+
+    /** an object which intercepts `/keys/query` requests on the test homeserver */
+    let e2eKeyResponder: E2EKeyResponder;
+
+    beforeEach(
+        async () => {
+            // anything that we don't have a specific matcher for silently returns a 404
+            fetchMock.catch(404);
+            fetchMock.config.warnOnFallback = false;
+
+            const homeserverUrl = "https://server.com";
+            aliceClient = createClient({
+                baseUrl: homeserverUrl,
+                userId: testData.TEST_USER_ID,
+                accessToken: "akjgkrgjsalice",
+                deviceId: testData.TEST_DEVICE_ID,
+            });
+
+            e2eKeyResponder = new E2EKeyResponder(homeserverUrl);
+            new E2EKeyReceiver(homeserverUrl);
+            const syncResponder = new SyncResponder(homeserverUrl);
+
+            // add bob as known user
+            syncResponder.sendOrQueueSyncResponse(getSyncResponse([testData.BOB_TEST_USER_ID]));
+
+            // Silence warnings from the backup manager
+            fetchMock.getOnce(new URL("/_matrix/client/v3/room_keys/version", homeserverUrl).toString(), {
+                status: 404,
+                body: { errcode: "M_NOT_FOUND" },
+            });
+
+            fetchMock.get(new URL("/_matrix/client/v3/pushrules/", homeserverUrl).toString(), {});
+            fetchMock.get(new URL("/_matrix/client/versions/", homeserverUrl).toString(), {});
+            fetchMock.post(
+                new URL(
+                    `/_matrix/client/v3/user/${encodeURIComponent(testData.TEST_USER_ID)}/filter`,
+                    homeserverUrl,
+                ).toString(),
+                { filter_id: "fid" },
+            );
+
+            await initCrypto(aliceClient);
+        },
+        /* it can take a while to initialise the crypto library on the first pass, so bump up the timeout. */
+        10000,
+    );
+
+    afterEach(async () => {
+        aliceClient.stopClient();
+        fetchMock.mockReset();
+    });
+
+    describe("encryptToDeviceMessages", () => {
+        it("returns empty batch for device that is not known", async () => {
+            await aliceClient.startClient();
+
+            const toDeviceBatch = await aliceClient
+                .getCrypto()
+                ?.encryptToDeviceMessages(
+                    "m.test.event",
+                    [{ userId: testData.BOB_TEST_USER_ID, deviceId: testData.BOB_TEST_DEVICE_ID }],
+                    {
+                        some: "content",
+                    },
+                );
+
+            expect(toDeviceBatch).toBeDefined();
+            const { batch, eventType } = toDeviceBatch!;
+            expect(eventType).toBe("m.room.encrypted");
+            expect(batch.length).toBe(0);
+        });
+
+        it("returns encrypted batch for known device", async () => {
+            await aliceClient.startClient();
+            e2eKeyResponder.addDeviceKeys(testData.BOB_SIGNED_TEST_DEVICE_DATA);
+            fetchMock.post("express:/_matrix/client/v3/keys/claim", () => ({
+                one_time_keys: testData.BOB_ONE_TIME_KEYS,
+            }));
+            await syncPromise(aliceClient);
+
+            const toDeviceBatch = await aliceClient
+                .getCrypto()
+                ?.encryptToDeviceMessages(
+                    "m.test.event",
+                    [{ userId: testData.BOB_TEST_USER_ID, deviceId: testData.BOB_TEST_DEVICE_ID }],
+                    {
+                        some: "content",
+                    },
+                );
+
+            expect(toDeviceBatch?.batch.length).toBe(1);
+            expect(toDeviceBatch?.eventType).toBe("m.room.encrypted");
+            const { deviceId, payload, userId } = toDeviceBatch!.batch[0];
+            expect(deviceId).toBe(testData.BOB_TEST_DEVICE_ID);
+            expect(userId).toBe(testData.BOB_TEST_USER_ID);
+            expect(payload.algorithm).toBe("m.olm.v1.curve25519-aes-sha2");
+            expect(payload.sender_key).toEqual(expect.any(String));
+            expect(payload.ciphertext).toEqual(
+                expect.objectContaining({
+                    [testData.BOB_SIGNED_TEST_DEVICE_DATA.keys[`curve25519:${testData.BOB_TEST_DEVICE_ID}`]]: {
+                        body: expect.any(String),
+                        type: 0,
+                    },
+                }),
+            );
+
+            // for future: check that bob's device can decrypt the ciphertext?
+        });
+    });
+});

spec/unit/crypto.spec.ts

@@ -26,6 +26,7 @@ import { CryptoBackend } from "../../src/common-crypto/CryptoBackend";
 import { EventDecryptionResult } from "../../src/common-crypto/CryptoBackend";
 import * as testData from "../test-utils/test-data";
 import { KnownMembership } from "../../src/@types/membership";
+import type { DeviceInfoMap } from "../../src/crypto/DeviceList";
 
 const Olm = global.Olm;
 
@@ -1245,6 +1246,117 @@ describe("Crypto", function () {
         });
     });
 
+    describe("encryptToDeviceMessages", () => {
+        let client: TestClient;
+        let ensureOlmSessionsForDevices: jest.SpiedFunction<typeof olmlib.ensureOlmSessionsForDevices>;
+        let encryptMessageForDevice: jest.SpiedFunction<typeof olmlib.encryptMessageForDevice>;
+        const payload = { hello: "world" };
+        let encryptedPayload: object;
+        let crypto: Crypto;
+
+        beforeEach(async () => {
+            ensureOlmSessionsForDevices = jest.spyOn(olmlib, "ensureOlmSessionsForDevices");
+            ensureOlmSessionsForDevices.mockResolvedValue(new Map());
+            encryptMessageForDevice = jest.spyOn(olmlib, "encryptMessageForDevice");
+            encryptMessageForDevice.mockImplementation(async (...[result, , , , , , payload]) => {
+                result.plaintext = { type: 0, body: JSON.stringify(payload) };
+            });
+
+            client = new TestClient("@alice:example.org", "aliceweb");
+
+            // running initCrypto should trigger a key upload
+            client.httpBackend.when("POST", "/keys/upload").respond(200, {});
+            await Promise.all([client.client.initCrypto(), client.httpBackend.flush("/keys/upload", 1)]);
+
+            encryptedPayload = {
+                algorithm: "m.olm.v1.curve25519-aes-sha2",
+                sender_key: client.client.crypto!.olmDevice.deviceCurve25519Key,
+                ciphertext: { plaintext: { type: 0, body: JSON.stringify(payload) } },
+            };
+
+            crypto = client.client.getCrypto() as Crypto;
+        });
+
+        afterEach(async () => {
+            ensureOlmSessionsForDevices.mockRestore();
+            encryptMessageForDevice.mockRestore();
+            await client.stop();
+        });
+
+        it("returns encrypted batch where devices known", async () => {
+            const deviceInfoMap: DeviceInfoMap = new Map([
+                [
+                    "@bob:example.org",
+                    new Map([
+                        ["bobweb", new DeviceInfo("bobweb")],
+                        ["bobmobile", new DeviceInfo("bobmobile")],
+                    ]),
+                ],
+                ["@carol:example.org", new Map([["caroldesktop", new DeviceInfo("caroldesktop")]])],
+            ]);
+            jest.spyOn(crypto.deviceList, "downloadKeys").mockResolvedValue(deviceInfoMap);
+            // const deviceInfoMap = await this.downloadKeys(Array.from(userIds), false);
+
+            const batch = await client.client.getCrypto()?.encryptToDeviceMessages(
+                "m.test.type",
+                [
+                    { userId: "@bob:example.org", deviceId: "bobweb" },
+                    { userId: "@bob:example.org", deviceId: "bobmobile" },
+                    { userId: "@carol:example.org", deviceId: "caroldesktop" },
+                    { userId: "@carol:example.org", deviceId: "carolmobile" }, // not known
+                ],
+                payload,
+            );
+            expect(crypto.deviceList.downloadKeys).toHaveBeenCalledWith(
+                ["@bob:example.org", "@carol:example.org"],
+                false,
+            );
+            expect(encryptMessageForDevice).toHaveBeenCalledTimes(3);
+            const expectedPayload = expect.objectContaining({
+                ...encryptedPayload,
+                "org.matrix.msgid": expect.any(String),
+                "sender_key": expect.any(String),
+            });
+            expect(batch?.eventType).toEqual("m.room.encrypted");
+            expect(batch?.batch.length).toEqual(3);
+            expect(batch).toEqual({
+                eventType: "m.room.encrypted",
+                batch: expect.arrayContaining([
+                    {
+                        userId: "@bob:example.org",
+                        deviceId: "bobweb",
+                        payload: expectedPayload,
+                    },
+                    {
+                        userId: "@bob:example.org",
+                        deviceId: "bobmobile",
+                        payload: expectedPayload,
+                    },
+                    {
+                        userId: "@carol:example.org",
+                        deviceId: "caroldesktop",
+                        payload: expectedPayload,
+                    },
+                ]),
+            });
+        });
+
+        it("returns empty batch if no devices known", async () => {
+            jest.spyOn(crypto.deviceList, "downloadKeys").mockResolvedValue(new Map());
+            const batch = await crypto.encryptToDeviceMessages(
+                "m.test.type",
+                [
+                    { deviceId: "AAA", userId: "@user1:domain" },
+                    { deviceId: "BBB", userId: "@user1:domain" },
+                    { deviceId: "CCC", userId: "@user2:domain" },
+                ],
+                payload,
+            );
+            expect(batch?.eventType).toEqual("m.room.encrypted");
+            expect(batch?.batch).toEqual([]);
+        });
+    });
+
     describe("checkSecretStoragePrivateKey", () => {
         let client: TestClient;