Store id_token and fix up logout implementation

src/domain/LogoutViewModel.ts

@@ -52,7 +52,7 @@ export class LogoutViewModel extends ViewModel<SegmentType, Options> {
         this.emitChange("busy");
         try {
             const client = new Client(this.platform);
-            await client.startLogout(this._sessionId);
+            await client.startLogout(this._sessionId, this.urlRouter);
             this.navigation.push("session", true);
         } catch (err) {
             this._error = err;

src/domain/navigation/URLRouter.ts

@@ -33,6 +33,7 @@ export interface IURLRouter<T> {
     openRoomActionUrl(roomId: string): string;
     createSSOCallbackURL(): string;
     createOIDCRedirectURL(): string;
+    createOIDCPostLogoutRedirectURL(): string;
     absoluteAppUrl(): string;
     absoluteUrlForAsset(asset: string): string;
     normalizeUrl(): void;
@@ -159,6 +160,10 @@ export class URLRouter<T extends {session: string | boolean}> implements IURLRou
         return window.location.origin;
     }
 
+    createOIDCPostLogoutRedirectURL(): string {
+        return window.location.origin;
+    }
+
     absoluteAppUrl(): string {
         return window.location.origin;
     }

src/matrix/Client.js

@@ -209,6 +209,10 @@ export class Client {
                     sessionInfo.expiresIn = loginData.expires_in;
                 }
 
+                if (loginData.id_token) {
+                    sessionInfo.idToken = loginData.id_token;
+                }
+
                 if (loginData.oidc_issuer) {
                     sessionInfo.oidcIssuer = loginData.oidc_issuer;
                     sessionInfo.oidcClientId = loginData.oidc_client_id;
@@ -236,7 +240,7 @@ export class Client {
         });
     }
 
-    async _createSessionAfterAuth({deviceId, userId, accessToken, refreshToken, homeserver, expiresIn, oidcIssuer, oidcClientId, accountManagementUrl}, inspectAccountSetup, log) {
+    async _createSessionAfterAuth({deviceId, userId, accessToken, refreshToken, homeserver, expiresIn, idToken, oidcIssuer, oidcClientId, accountManagementUrl}, inspectAccountSetup, log) {
         const id = this.createNewSessionId();
         const lastUsed = this._platform.clock.now();
         const sessionInfo = {
@@ -251,6 +255,7 @@ export class Client {
             oidcIssuer,
             oidcClientId,
             accountManagementUrl,
+            idToken,
         };
         if (expiresIn) {
             sessionInfo.accessTokenExpiresAt = lastUsed + expiresIn * 1000;
@@ -497,34 +502,51 @@ export class Client {
         return !this._reconnector;
     }
 
-    startLogout(sessionId) {
+    startLogout(sessionId, urlRouter) {
         return this._platform.logger.run("logout", async log => {
             this._sessionId = sessionId;
             log.set("id", this._sessionId);
             const sessionInfo = await this._platform.sessionInfoStorage.get(this._sessionId);
             if (!sessionInfo) {
                 throw new Error(`Could not find session for id ${this._sessionId}`);
             }
+            let endSessionRedirectEndpoint;
             try {
-                const hsApi = new HomeServerApi({
-                    homeserver: sessionInfo.homeServer,
-                    accessToken: sessionInfo.accessToken,
-                    request: this._platform.request
-                });
-                await hsApi.logout({log}).response();
-                const oidcApi = new OidcApi({
-                    issuer: sessionInfo.oidcIssuer,
-                    clientId: sessionInfo.oidcClientId,
-                    request: this._platform.request,
-                    encoding: this._platform.encoding,
-                    crypto: this._platform.crypto,
-                });
-                await oidcApi.revokeToken({ token: sessionInfo.accessToken, type: "access" });
-                if (sessionInfo.refreshToken) {
-                    await oidcApi.revokeToken({ token: sessionInfo.refreshToken, type: "refresh" });
+                if (sessionInfo.oidcClientId) {
+                    // OIDC logout
+                    const oidcApi = new OidcApi({
+                        issuer: sessionInfo.oidcIssuer,
+                        clientId: sessionInfo.oidcClientId,
+                        request: this._platform.request,
+                        encoding: this._platform.encoding,
+                        crypto: this._platform.crypto,
+                        urlRouter,
+                    });
+                    await oidcApi.revokeToken({ token: sessionInfo.accessToken, type: "access" });
+                    if (sessionInfo.refreshToken) {
+                        await oidcApi.revokeToken({ token: sessionInfo.refreshToken, type: "refresh" });
+                    }
+                    endSessionRedirectEndpoint = await oidcApi.endSessionEndpoint({
+                        idTokenHint: sessionInfo.idToken,
+                        logoutHint: sessionInfo.userId,
+                    })
+                } else {
+                    // regular logout
+                    const hsApi = new HomeServerApi({
+                        homeserver: sessionInfo.homeServer,
+                        accessToken: sessionInfo.accessToken,
+                        request: this._platform.request
+                    });
+                    await hsApi.logout({log}).response();
                 }
-            } catch (err) {}
+            } catch (err) {
+                console.error(err);
+            }
             await this.deleteSession(log);
+            // OIDC might have given us a redirect URI to go to do tell the OP we are signing out
+            if (endSessionRedirectEndpoint) {
+                this._platform.openUrl(endSessionRedirectEndpoint);
+            }
         });
     }
 

src/matrix/login/OIDCLoginMethod.ts

@@ -55,7 +55,7 @@ export class OIDCLoginMethod implements ILoginMethod {
     }
 
     async login(hsApi: HomeServerApi, _deviceName: string, log: ILogItem): Promise<Record<string, any>> {
-        const { access_token, refresh_token, expires_in } = await this._oidcApi.completeAuthorizationCodeGrant({
+        const { access_token, refresh_token, expires_in, id_token } = await this._oidcApi.completeAuthorizationCodeGrant({
             code: this._code,
             codeVerifier: this._codeVerifier,
             redirectUri: this._redirectUri,
@@ -72,6 +72,6 @@ export class OIDCLoginMethod implements ILoginMethod {
         const oidc_issuer = this._oidcApi.issuer;
         const oidc_client_id = await this._oidcApi.clientId();
 
-        return { oidc_issuer, oidc_client_id, access_token, refresh_token, expires_in, user_id, device_id, oidc_account_management_url: this._accountManagementUrl };
+        return { oidc_issuer, oidc_client_id, access_token, refresh_token, expires_in, id_token, user_id, device_id, oidc_account_management_url: this._accountManagementUrl };
     }
 }

src/matrix/net/OidcApi.ts

@@ -30,6 +30,7 @@ type BearerToken = {
     access_token: string,
     refresh_token?: string,
     expires_in?: number,
+    id_token?: string,
 }
 
 const isValidBearerToken = (t: any): t is BearerToken =>
@@ -48,6 +49,28 @@ type AuthorizationParams = {
     codeVerifier?: string,
 };
 
+/**
+ * @see https://openid.net/specs/openid-connect-rpinitiated-1_0.html
+ */
+type LogoutParams = {
+    /**
+     * Maps to the `id_token_hint` parameter.
+     */
+    idTokenHint?: string,
+    /**
+     * Maps to the `state` parameter.
+     */
+    state?: string,
+    /**
+     * Maps to the `post_logout_redirect_uri` parameter.
+     */
+    redirectUri?: string,
+    /**
+     * Maps to the `logout_hint` parameter.
+     */
+    logoutHint?: string,
+};
+
 function assert(condition: any, message: string): asserts condition {
     if (!condition) {
         throw new Error(`Assertion failed: ${message}`);
@@ -97,6 +120,7 @@ export class OidcApi<N extends object = SegmentType> {
             redirect_uris: [this._urlRouter.createOIDCRedirectURL()],
             id_token_signed_response_alg: "RS256",
             token_endpoint_auth_method: "none",
+            post_logout_redirect_uris: [this._urlRouter.createOIDCPostLogoutRedirectURL()],
         };
     }
 
@@ -226,6 +250,30 @@ export class OidcApi<N extends object = SegmentType> {
         return metadata["revocation_endpoint"];
     }
 
+    async endSessionEndpoint({idTokenHint, logoutHint, redirectUri, state}: LogoutParams): Promise<string | undefined> {
+        const metadata = await this.metadata();
+        const endpoint = metadata["end_session_endpoint"];
+        if (!endpoint) {
+            return undefined;
+        }
+        if (!redirectUri) {
+            redirectUri =  this._urlRouter.createOIDCPostLogoutRedirectURL();
+        }
+        const url = new URL(endpoint);
+        url.searchParams.append("client_id", await this.clientId());
+        url.searchParams.append("post_logout_redirect_uri", redirectUri);
+        if (idTokenHint) {
+            url.searchParams.append("id_token_hint", idTokenHint);
+        }
+        if (logoutHint) {
+            url.searchParams.append("logout_hint", logoutHint);
+        }
+        if (state) {
+            url.searchParams.append("state", state);
+        }
+        return url.href;
+    }
+
     async isGuestAvailable(): Promise<boolean> {
         const metadata = await this.metadata();
         return metadata["scopes_supported"]?.includes("urn:matrix:org.matrix.msc2967.client:api:guest");
@@ -331,7 +379,6 @@ export class OidcApi<N extends object = SegmentType> {
         const req = this._requestFn(revocationEndpoint, {
             method: "POST",
             headers,
-            format: "json",
             body,
         });
 

src/matrix/sessioninfo/localstorage/SessionInfoStorage.ts

@@ -26,6 +26,7 @@ interface ISessionInfo {
     oidcIssuer?: string;
     accountManagementUrl?: string;
     lastUsed: number;
+    idToken?: string;
 }
 
 // todo: this should probably be in platform/types?