WIP: MSC2918 initial implementation

Author: sandhose

src/matrix/SessionContainer.js

@@ -21,6 +21,7 @@ import {Reconnector, ConnectionStatus} from "./net/Reconnector.js";
 import {ExponentialRetryDelay} from "./net/ExponentialRetryDelay.js";
 import {MediaRepository} from "./net/MediaRepository.js";
 import {RequestScheduler} from "./net/RequestScheduler.js";
+import {TokenRefresher} from "./net/TokenRefresher.js";
 import {HomeServerError, ConnectionError, AbortError} from "./error.js";
 import {Sync, SyncStatus} from "./Sync.js";
 import {Session} from "./Session.js";
@@ -105,7 +106,13 @@ export class SessionContainer {
                 accessToken: loginData.access_token,
                 lastUsed: clock.now()
             };
-            await this._platform.sessionInfoStorage.add(sessionInfo);            
+
+            if (loginData.refresh_token) {
+                sessionInfo.accessTokenExpiresAt = clock.now() + loginData.expires_in * 1000;
+                sessionInfo.refreshToken = loginData.refresh_token;
+            }
+
+            await this._platform.sessionInfoStorage.add(sessionInfo);
         } catch (err) {
             this._error = err;
             if (err instanceof HomeServerError) {
@@ -143,13 +150,31 @@ export class SessionContainer {
             retryDelay: new ExponentialRetryDelay(clock.createTimeout),
             createMeasure: clock.createMeasure
         });
+
+        let accessToken;
+        if (sessionInfo.refreshToken) {
+            this._tokenRefresher = new TokenRefresher({
+                accessToken: sessionInfo.accessToken,
+                accessTokenExpiresAt: sessionInfo.accessTokenExpiresAt,
+                refreshToken: sessionInfo.refreshToken,
+                anticipation: 10 * 1000, // Refresh 10 seconds before the expiration
+                clock,
+            });
+            accessToken = this._tokenRefresher.accessToken;
+        } else {
+            accessToken = new ObservableValue(sessionInfo.accessToken);
+        }
+
         const hsApi = new HomeServerApi({
             homeServer: sessionInfo.homeServer,
-            accessToken: sessionInfo.accessToken,
+            accessToken,
             request: this._platform.request,
             reconnector: this._reconnector,
             createTimeout: clock.createTimeout
         });
+        if (this._tokenRefresher) {
+            await this._tokenRefresher.start(hsApi);
+        }
         this._sessionId = sessionInfo.id;
         this._storage = await this._platform.storageFactory.create(sessionInfo.id);
         // no need to pass access token to session

src/matrix/net/HomeServerApi.js

@@ -101,6 +101,10 @@ export class HomeServerApi {
         return `${this._homeserver}/_matrix/client/r0${csPath}`;
     }
 
+    _unstableUrl(feature, csPath) {
+        return `${this._homeserver}/_matrix/client/unstable/${feature}${csPath}`;
+    }
+
     _baseRequest(method, url, queryParams, body, options, accessToken) {
         const queryString = encodeQueryParams(queryParams);
         url = `${url}?${queryString}`;
@@ -157,7 +161,7 @@ export class HomeServerApi {
     }
 
     _authedRequest(method, url, queryParams, body, options) {
-        return this._baseRequest(method, url, queryParams, body, options, this._accessToken);
+        return this._baseRequest(method, url, queryParams, body, options, this._accessToken.get());
     }
 
     _post(csPath, queryParams, body, options) {
@@ -196,7 +200,9 @@ export class HomeServerApi {
     }
 
     passwordLogin(username, password, initialDeviceDisplayName, options = null) {
-        return this._unauthedRequest("POST", this._url("/login"), null, {
+        return this._unauthedRequest("POST", this._url("/login"), {
+          "org.matrix.msc2918.refresh_token": "true"
+        }, {
           "type": "m.login.password",
           "identifier": {
             "type": "m.id.user",
@@ -207,6 +213,12 @@ export class HomeServerApi {
         }, options);
     }
 
+    refreshToken(token, options = null) {
+        return this._unauthedRequest("POST", this._unstableUrl("org.matrix.msc2918.refresh_token", "/refresh"), null, {
+            "refresh_token": token
+        }, options);
+    }
+
     createFilter(userId, filter, options = null) {
         return this._post(`/user/${encodeURIComponent(userId)}/filter`, null, filter, options);
     }

src/matrix/net/TokenRefresher.js

@@ -0,0 +1,70 @@
+import { ObservableValue } from "../../observable/ObservableValue.js";
+
+export class TokenRefresher {
+    constructor({
+        refreshToken,
+        accessToken,
+        accessTokenExpiresAt,
+        anticipation,
+        clock,
+    }) {
+        this._refreshToken = new ObservableValue(refreshToken);
+        this._accessToken = new ObservableValue(accessToken);
+        this._accessTokenExpiresAt = new ObservableValue(accessTokenExpiresAt);
+        this._anticipation = anticipation;
+        this._clock = clock;
+    }
+
+    async start(hsApi) {
+        this._hsApi = hsApi;
+        if (this.needsRenewing) {
+            await this.renew();
+        }
+
+        this._renewingLoop();
+    }
+
+    get needsRenewing() {
+        const remaining = this._accessTokenExpiresAt.get() - this._clock.now();
+        const anticipated = remaining - this._anticipation;
+        return anticipated < 0;
+    }
+
+    async _renewingLoop() {
+        while (true) {
+            const remaining =
+                this._accessTokenExpiresAt.get() - this._clock.now();
+            const anticipated = remaining - this._anticipation;
+
+            if (anticipated > 0) {
+                this._timeout = this._clock.createTimeout(anticipated);
+                await this._timeout.elapsed();
+            }
+
+            await this.renew();
+        }
+    }
+
+    async renew() {
+        const response = await this._hsApi
+            .refreshToken(this._refreshToken.get())
+            .response();
+
+        if (response["refresh_token"]) {
+            this._refreshToken.set(response["refresh_token"]);
+        }
+
+        this._accessToken.set(response["access_token"]);
+        this._accessTokenExpiresAt.set(
+            this._clock.now() + response["expires_in"] * 1000
+        );
+    }
+
+    get accessToken() {
+        return this._accessToken;
+    }
+
+    get refreshToken() {
+        return this._refreshToken;
+    }
+}