feat: sign in through the bulwark-mobile client on stalwart 1.0 (bulwarkmail/webmail#1459)

src/api/__tests__/live-stalwart-auth.test.ts

@@ -17,8 +17,10 @@
  * started.
  *
  * What differs between the lines (checked on 0.16.27 and 1.0.0):
- * - 1.0 knows only registered clients, so the app registers its own public
- *   client (RFC 7591); 0.16 takes `bulwark-webmail`.
+ * - 1.0 knows only registered clients, so the app signs in as
+ *   `bulwark-mobile` where the webmail's admin OAuth setup registered it
+ *   (webmail #1459), else registers its own public client (RFC 7591); 0.16
+ *   takes `bulwark-webmail`. The run checks whichever the server has.
  * - 1.0 rotates refresh tokens and revokes the whole grant when a superseded
  *   one comes back after its successor was used.
  * - 1.0 has a revocation endpoint; 0.16 has none.
@@ -49,6 +51,7 @@ import {
 } from '../account-security';
 import {
   DEFAULT_CLIENT_ID,
+  MOBILE_CLIENT_ID,
   REGISTERED_REDIRECT_URI,
   exchangePasswordForTokens,
   resolveLoginClient,
@@ -116,6 +119,14 @@ async function nextTotpCode(): Promise<string> {
 
 // Stalwart 1.0 is the line with RP-initiated logout; 0.16 has none.
 let isV1 = false;
+// A 1.0 where the webmail's admin OAuth setup registered `bulwark-mobile`.
+let hasMobileClient = false;
+
+/** The client a 1.0 sign-in must have used. */
+function expectV1Client(clientId: string | null | undefined): void {
+  if (hasMobileClient) expect(clientId).toBe(MOBILE_CLIENT_ID);
+  else expect(clientId).toMatch(/^swc1\./);
+}
 
 function useSingleton(client: JMAPClient): void {
   (jmapClient as unknown as JMAPClient).restoreSnapshot(client.snapshot());
@@ -140,6 +151,18 @@ live('live Stalwart sign-in', () => {
   beforeAll(async () => {
     const metadata = await discoverOAuthMetadata(SERVER);
     isV1 = !!(metadata as { end_session_endpoint?: string } | null)?.end_session_endpoint;
+    if (isV1) {
+      const query = new URLSearchParams({
+        response_type: 'code',
+        client_id: MOBILE_CLIENT_ID,
+        redirect_uri: REGISTERED_REDIRECT_URI,
+        state: 's',
+        code_challenge: 'A'.repeat(43),
+        code_challenge_method: 'S256',
+      });
+      const check = (await (await fetch(`${SERVER}/api/auth/client?${query}`)).json()) as { error?: string };
+      hasMobileClient = !check.error;
+    }
     // Optional so the suite also runs against older sign-in code, to show
     // what it does on a server.
     resetLoginClients?.();
@@ -166,7 +189,7 @@ live('live Stalwart sign-in', () => {
     it('signs in with a client the server accepts, on a redirect it accepts', async () => {
       const client = await resolveLoginClient(SERVER);
       if (isV1) {
-        expect(client.clientId).toMatch(/^swc1\./);
+        expectV1Client(client.clientId);
         expect(client.redirectUri).toBe(REGISTERED_REDIRECT_URI);
         // The browser sign-in's authorization request with this client and
         // the scopes the app asks for passes 1.0's client check.
@@ -182,7 +205,8 @@ live('live Stalwart sign-in', () => {
         });
         const check = (await (await fetch(`${SERVER}/api/auth/client?${query}`)).json()) as { error?: string; scopes?: string[] };
         expect(check.error).toBeUndefined();
-        expect(check.scopes?.length).toBeGreaterThan(1);
+        // A first-party client shows as one scope, "Full access to your account".
+        expect(check.scopes?.length).toBeGreaterThan(hasMobileClient ? 0 : 1);
       } else {
         expect(client).toEqual({ clientId: DEFAULT_CLIENT_ID, redirectUri: HANDOFF_REDIRECT_URI });
       }
@@ -208,7 +232,7 @@ live('live Stalwart sign-in', () => {
       expect(tokens.accessToken).toBeTruthy();
       expect(tokens.refreshToken).toBeTruthy();
       expect(tokens.tokenEndpoint).toBe(`${SERVER}/auth/token`);
-      if (isV1) expect(tokens.clientId).toMatch(/^swc1\./);
+      if (isV1) expectV1Client(tokens.clientId);
       else expect(tokens.clientId).toBe(DEFAULT_CLIENT_ID);
     });
 
@@ -237,9 +261,9 @@ live('live Stalwart sign-in', () => {
       expect(await client.forceRefreshToken()).toBe(true);
     }, 30_000);
 
-    it('account security: 1.0 refuses it to the registered client, 0.16 allows it', async () => {
+    it('account security: 1.0 refuses it to the registered client, allows it to bulwark-mobile; 0.16 allows it', async () => {
       useSingleton(client);
-      if (isV1) {
+      if (isV1 && !hasMobileClient) {
         // The session hides the extension from this client, and the calls
         // themselves are refused.
         expect(isStalwartSupported()).toBe(false);
@@ -317,7 +341,7 @@ live('live Stalwart sign-in', () => {
     const authUrl = new URL(browser.mock.calls[0][0] as string);
     expect(`${authUrl.origin}${authUrl.pathname}`).toBe(metadata.authorization_endpoint);
     if (isV1) {
-      expect(authUrl.searchParams.get('client_id')).toMatch(/^swc1\./);
+      expectV1Client(authUrl.searchParams.get('client_id'));
       expect(metadata.registration_endpoint).toBeTruthy();
     } else {
       // 0.16 on :8016 names its public address, not the one typed here, and
@@ -355,7 +379,7 @@ live('live Stalwart sign-in', () => {
       tokenSource: string;
     };
     expect(stored.tokenSource).toBe('totp');
-    if (isV1) expect(stored.clientId).toMatch(/^swc1\./);
+    if (isV1) expectV1Client(stored.clientId);
     else expect(stored.clientId).toBe(DEFAULT_CLIENT_ID);
     const res = await client.request([['Mailbox/get', { accountId: client.accountId, properties: ['role'] }, '0']]);
     expect(res.methodResponses[0][0]).toBe('Mailbox/get');

src/lib/__tests__/totp-login.test.ts

@@ -7,6 +7,7 @@ import {
   resolveLoginClient,
   TotpLoginError,
   REGISTERED_REDIRECT_URI,
+  MOBILE_CLIENT_ID,
 } from '../totp-login';
 import { describeLoginError } from '../login-errors';
 
@@ -31,19 +32,28 @@ function json(body: unknown, status = 200): Response {
 interface Call { url: string; method: string; body?: string }
 
 // A fake Stalwart of either line. `v1` knows no client but the ones it
-// registered (ids `swc1.<n>`), takes `{query, consent}` and answers with a
+// registered (ids `swc1.<n>`) and those in `admin` (registered by an admin
+// for the given redirect URI), takes `{query, consent}` and answers with a
 // location; 0.16 has no client check and answers `client_code`.
-function fakeServer(version: '0.16' | '1.0', answer?: (query: URLSearchParams) => unknown) {
+function fakeServer(
+  version: '0.16' | '1.0',
+  answer?: (query: URLSearchParams) => unknown,
+  admin: Record<string, string> = {},
+) {
   const calls: Call[] = [];
   let registered = 0;
+  const knows = (clientId: string, redirectUri: string | null) =>
+    clientId.startsWith('swc1.') || (clientId in admin && admin[clientId] === redirectUri);
   fetchMock.mockImplementation(async (url: string, init?: RequestInit) => {
     const call = { url, method: init?.method ?? 'GET', body: typeof init?.body === 'string' ? init.body : undefined };
     calls.push(call);
     const path = url.slice(BASE.length).split('?')[0];
     if (path === '/api/auth/client') {
       if (version === '0.16') return json({ type: 'about:blank', status: 404 }, 404);
-      const clientId = new URL(url).searchParams.get('client_id') ?? '';
-      return json(clientId.startsWith('swc1.') ? { name: 'Bulwark Mobile' } : { error: 'invalid_client', description: 'Unknown client id', redirect: false });
+      const params = new URL(url).searchParams;
+      return json(knows(params.get('client_id') ?? '', params.get('redirect_uri'))
+        ? { name: 'Bulwark Mobile' }
+        : { error: 'invalid_client', description: 'Unknown client id', redirect: false });
     }
     if (path === '/auth/register') {
       if (version === '0.16') return json({ error: 'invalid_redirect_uri' }, 400);
@@ -56,7 +66,7 @@ function fakeServer(version: '0.16' | '1.0', answer?: (query: URLSearchParams) =
       if (typeof body.query !== 'string') return json({ title: 'Invalid parameters', detail: 'JSON deserialization failed' }, 400);
       const query = new URLSearchParams(body.query);
       if (answer) return json(answer(query));
-      if (!query.get('client_id')?.startsWith('swc1.')) return json({ type: 'invalid', error: 'invalid_client', description: 'Unknown client id' });
+      if (!knows(query.get('client_id') ?? '', query.get('redirect_uri'))) return json({ type: 'invalid', error: 'invalid_client', description: 'Unknown client id' });
       return json({
         type: 'authenticated',
         location: `${query.get('redirect_uri')}?code=code-10&state=${query.get('state')}&iss=x`,
@@ -111,6 +121,21 @@ describe('exchangePasswordForTokens', () => {
     expect(tokenCall(calls).get('redirect_uri')).toBe(REGISTERED_REDIRECT_URI);
   });
 
+  it('signs in on Stalwart 1.0 through the bulwark-mobile client the webmail setup registered (webmail #1459)', async () => {
+    const calls = fakeServer('1.0', undefined, { 'bulwark-mobile': REGISTERED_REDIRECT_URI });
+    const tokens = await exchangePasswordForTokens(BASE, 'u@example.org', 'pw', '123456');
+
+    expect(tokens.clientId).toBe(MOBILE_CLIENT_ID);
+    expect(calls.some((c) => c.url.endsWith('/auth/register'))).toBe(false);
+    const query = new URLSearchParams(JSON.parse(authCalls(calls)[0].body!).query);
+    expect(query.get('client_id')).toBe(MOBILE_CLIENT_ID);
+    expect(query.get('redirect_uri')).toBe(REGISTERED_REDIRECT_URI);
+    expect(tokenCall(calls).get('client_id')).toBe(MOBILE_CLIENT_ID);
+    expect(tokenCall(calls).get('redirect_uri')).toBe(REGISTERED_REDIRECT_URI);
+    // A public client: there is no secret to send.
+    expect(tokenCall(calls).has('client_secret')).toBe(false);
+  });
+
   it('keeps the registered client per server for the next sign-in', async () => {
     fakeServer('1.0');
     await exchangePasswordForTokens(BASE, 'u@example.org', 'pw', '123456');
@@ -289,6 +314,27 @@ describe('resolveLoginClient', () => {
     const client = await resolveLoginClient(BASE, { registrationEndpoint: 'https://public.example.com/auth/register' });
 
     expect(client.clientId).toBe('swc1.pub');
-    expect(urls).toEqual([`${BASE}/api/auth/client`, 'https://public.example.com/auth/register']);
+    expect(urls).toEqual([`${BASE}/api/auth/client`, `${BASE}/api/auth/client`, 'https://public.example.com/auth/register']);
+  });
+
+  it('asks for bulwark-mobile first, then the webmail client, before registering one', async () => {
+    const calls = fakeServer('1.0');
+    await resolveLoginClient(BASE);
+
+    const checked = calls
+      .filter((c) => c.url.startsWith(`${BASE}/api/auth/client`))
+      .map((c) => new URL(c.url).searchParams);
+    expect(checked.map((p) => [p.get('client_id'), p.get('redirect_uri')])).toEqual([
+      [MOBILE_CLIENT_ID, REGISTERED_REDIRECT_URI],
+      ['bulwark-webmail', 'bulwarkmobile://auth/callback'],
+    ]);
+  });
+
+  it('remembers bulwark-mobile for the next sign-in', async () => {
+    fakeServer('1.0', undefined, { 'bulwark-mobile': REGISTERED_REDIRECT_URI });
+    await resolveLoginClient(BASE);
+    const calls = fakeServer('1.0', undefined, { 'bulwark-mobile': REGISTERED_REDIRECT_URI });
+    expect((await resolveLoginClient(BASE)).clientId).toBe(MOBILE_CLIENT_ID);
+    expect(calls).toHaveLength(0);
   });
 });

src/lib/totp-login.ts

@@ -36,14 +36,23 @@ export const DEFAULT_CLIENT_ID = 'bulwark-webmail';
 
 /**
  * Redirect URI of the client the app registers at a Stalwart 1.0 that knows
- * no client for it. 1.0 lets a public client register only a loopback URI or
- * a private-use scheme with a dot in it (RFC 8252), which `bulwarkmobile://`
- * is not; this one is the iOS bundle id. The password login never visits it
- * (/api/auth hands the location back); the browser sign-in comes back on it,
- * so the app registers the scheme too.
+ * no client for it, and of `bulwark-mobile`. 1.0 lets a public client
+ * register only a loopback URI or a private-use scheme with a dot in it
+ * (RFC 8252), which `bulwarkmobile://` is not; this one is the App Store and
+ * Play id. The password login never visits it (/api/auth hands the location
+ * back); the browser sign-in comes back on it, so the app registers the
+ * scheme too.
  */
 export const REGISTERED_REDIRECT_URI = 'org.bulwarkmail.mobile:/auth/callback';
 
+/**
+ * The app's own client, which the webmail's admin OAuth setup registers on
+ * Stalwart 1.0 (webmail #1459): public and first-party, so its tokens reach
+ * the account's Stalwart settings, which those of a client the app
+ * registers itself don't.
+ */
+export const MOBILE_CLIENT_ID = 'bulwark-mobile';
+
 /**
  * The data scopes Stalwart 1.0 grants a client that isn't first-party. A
  * token reaches only what these name (no scope: nothing but the session);
@@ -189,27 +198,20 @@ async function registerPublicClient(base: string, url = `${base}/auth/register`)
 }
 
 /**
- * The OAuth client to sign in to `serverUrl` as. Stalwart 1.0's client check
- * (GET /api/auth/client, which 0.16 doesn't have) says whether it knows the
- * webmail's client id with the app's redirect URI; when it doesn't, the app
- * registers its own public client, at `registrationEndpoint` when the OAuth
- * metadata names one. Any other server, and 0.16, gets `bulwark-webmail` as
- * before. A server having a bad moment (5xx, 429) gets the default without
- * it being remembered; an unreachable one throws `NetworkError`, as the
- * default would only end in the server refusing a client it doesn't know.
+ * Stalwart 1.0's client check (GET /api/auth/client, which 0.16 doesn't
+ * have): does the server take `clientId` on `redirectUri`? `busy` for a
+ * server having a bad moment (5xx, 429), `none` where there is no such
+ * check; an unreachable server throws `NetworkError`.
  */
-export async function resolveLoginClient(
-  serverUrl: string,
-  opts?: { registrationEndpoint?: string },
-): Promise<LoginClient> {
-  const base = trimBase(serverUrl);
-  const cached = loginClients.get(base);
-  if (cached) return cached;
-  const fallback: LoginClient = { clientId: DEFAULT_CLIENT_ID, redirectUri: HANDOFF_REDIRECT_URI };
+async function checkClient(
+  base: string,
+  clientId: string,
+  redirectUri: string,
+): Promise<'known' | 'unknown' | 'none' | 'busy'> {
   const query = new URLSearchParams({
     response_type: 'code',
-    client_id: DEFAULT_CLIENT_ID,
-    redirect_uri: HANDOFF_REDIRECT_URI,
+    client_id: clientId,
+    redirect_uri: redirectUri,
     state: 'probe',
     code_challenge: 'A'.repeat(43),
     code_challenge_method: 'S256',
@@ -228,24 +230,50 @@ export async function resolveLoginClient(
   } finally {
     t.done();
   }
-  if (!response || typeof response.status !== 'number') return fallback;
+  if (!response || typeof response.status !== 'number') return 'busy';
   assertSameServer(url, response);
-  if (response.status >= 500 || response.status === 429 || response.status === 408) return fallback;
+  if (response.status >= 500 || response.status === 429 || response.status === 408) return 'busy';
   // 0.16 and servers that aren't Stalwart: no such endpoint.
-  if (!response.ok) {
-    rememberClient(base, fallback);
-    return fallback;
-  }
+  if (!response.ok) return 'none';
   const body = (await response.json().catch(() => null)) as { error?: unknown } | null;
-  if (!body || typeof body !== 'object') {
-    rememberClient(base, fallback);
-    return fallback;
+  if (!body || typeof body !== 'object') return 'none';
+  // `invalid_client` (unknown id) or a redirect URI the client doesn't list.
+  return typeof body.error === 'string' && body.error ? 'unknown' : 'known';
+}
+
+/**
+ * The OAuth client to sign in to `serverUrl` as. On Stalwart 1.0 that is
+ * `bulwark-mobile` where the admin's OAuth setup registered it, else the
+ * webmail's client if it takes the app's redirect URI, else a public client
+ * the app registers itself, at `registrationEndpoint` when the OAuth
+ * metadata names one. Any other server, and 0.16, gets `bulwark-webmail` as
+ * before. A server having a bad moment (5xx, 429) gets the default without
+ * it being remembered; an unreachable one throws `NetworkError`, as the
+ * default would only end in the server refusing a client it doesn't know.
+ */
+export async function resolveLoginClient(
+  serverUrl: string,
+  opts?: { registrationEndpoint?: string },
+): Promise<LoginClient> {
+  const base = trimBase(serverUrl);
+  const cached = loginClients.get(base);
+  if (cached) return cached;
+  const fallback: LoginClient = { clientId: DEFAULT_CLIENT_ID, redirectUri: HANDOFF_REDIRECT_URI };
+
+  const own = await checkClient(base, MOBILE_CLIENT_ID, REGISTERED_REDIRECT_URI);
+  if (own === 'busy') return fallback;
+  if (own === 'known') {
+    const client = { clientId: MOBILE_CLIENT_ID, redirectUri: REGISTERED_REDIRECT_URI };
+    rememberClient(base, client);
+    return client;
   }
-  // `invalid_client` (unknown id) or a redirect URI the admin's client
-  // doesn't list: either way the webmail's client isn't the app's to use.
-  if (typeof body.error === 'string' && body.error) {
-    const endpoint = opts?.registrationEndpoint;
-    return registerPublicClient(base, endpoint && /^https?:\/\//i.test(endpoint) ? endpoint : undefined);
+  if (own === 'unknown') {
+    const shared = await checkClient(base, DEFAULT_CLIENT_ID, HANDOFF_REDIRECT_URI);
+    if (shared === 'busy') return fallback;
+    if (shared === 'unknown') {
+      const endpoint = opts?.registrationEndpoint;
+      return registerPublicClient(base, endpoint && /^https?:\/\//i.test(endpoint) ? endpoint : undefined);
+    }
   }
   rememberClient(base, fallback);
   return fallback;