WIP

src/domain/session/room/RoomViewModel.js

@@ -28,6 +28,7 @@ import {LocalMedia} from "../../../matrix/calls/LocalMedia";
 // this is a breaking SDK change though to make this option mandatory
 import {tileClassForEntry as defaultTileClassForEntry} from "./timeline/tiles/index";
 import {joinRoom} from "../../../matrix/room/joinRoom";
+import {SASVerification} from "../../../matrix/verification/SAS/SASVerification";
 
 export class RoomViewModel extends ErrorReportViewModel {
     constructor(options) {
@@ -49,6 +50,15 @@ export class RoomViewModel extends ErrorReportViewModel {
         this._setupCallViewModel();
     }
 
+    async _startCrossSigning(otherUserId) {
+        await this.logAndCatch("startCrossSigning", async log => {
+            const session = this.getOption("session");
+            const { userId, deviceId } = session;
+            const sas = new SASVerification(this.room, { userId, deviceId }, otherUserId, log);
+            await sas.start();
+        });
+    }
+
     _setupCallViewModel() {
         if (!this.features.calls) {
             return;

src/matrix/verification/SAS/SASVerification.ts

@@ -0,0 +1,33 @@
+/*
+Copyright 2023 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 {StartVerificationStage} from "./stages/StartVerificationStage";
+import type {ILogItem} from "../../../logging/types";
+import type {Room} from "../../room/Room.js";
+import type {BaseSASVerificationStage, UserData} from "./stages/BaseSASVerificationStage";
+
+export class SASVerification {
+    private stages: BaseSASVerificationStage[] = [];
+   
+    constructor(private room: Room, private ourUser: UserData, otherUserId: string, log: ILogItem) {
+        this.stages.push(new StartVerificationStage(room, ourUser, otherUserId, log));
+    }
+
+    async start() {
+        for (const stage of this.stages) {
+            await stage.completeStage(); 
+        }
+    }
+}

src/matrix/verification/SAS/stages/BaseSASVerificationStage.ts

@@ -0,0 +1,35 @@
+/*
+Copyright 2023 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 type {ILogItem} from "../../../../lib.js";
+import type {Room} from "../../../room/Room.js";
+
+export type UserData = {
+    userId: string;
+    deviceId: string;
+}
+
+export abstract class BaseSASVerificationStage {
+    constructor(protected room: Room,
+        protected ourUser: UserData,
+        protected otherUserId: string,
+        protected log: ILogItem) {
+
+    }
+
+    abstract get type(): string;
+    abstract completeStage(): boolean | Promise<boolean>;
+    abstract get nextStage(): BaseSASVerificationStage;
+}

src/matrix/verification/SAS/stages/StartVerificationStage.ts

@@ -0,0 +1,55 @@
+/*
+Copyright 2023 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 {BaseSASVerificationStage} from "./BaseSASVerificationStage";
+
+// From element-web
+// type KeyAgreement = "curve25519-hkdf-sha256" | "curve25519";
+// type MacMethod = "hkdf-hmac-sha256.v2" | "org.matrix.msc3783.hkdf-hmac-sha256" | "hkdf-hmac-sha256" | "hmac-sha256";
+
+// const KEY_AGREEMENT_LIST: KeyAgreement[] = ["curve25519-hkdf-sha256", "curve25519"];
+// const HASHES_LIST = ["sha256"];
+// const MAC_LIST: MacMethod[] = [
+//     "hkdf-hmac-sha256.v2",
+//     "org.matrix.msc3783.hkdf-hmac-sha256",
+//     "hkdf-hmac-sha256",
+//     "hmac-sha256",
+// ];
+
+// const SAS_LIST = Object.keys(sasGenerators);
+export class StartVerificationStage extends BaseSASVerificationStage {
+    
+    async completeStage() {
+        await this.log.wrap("StartVerificationStage.completeStage", async (log) => {
+            const content = {
+                "body": `${this.ourUser.userId} is requesting to verify your device, but your client does not support verification, so you may need to use a different verification method.`,
+                "from_device": this.ourUser.deviceId,
+                "methods": ["m.sas.v1"],
+                "msgtype": "m.key.verification.request",
+                "to": this.otherUserId,
+            };
+            await this.room.sendEvent("m.room.message", content, null, log);
+        });
+        return true;
+    }
+
+    get type() {
+        return "m.key.verification.request";
+    }
+
+    get nextStage(): BaseSASVerificationStage {
+        return this;    
+    }
+}