🚪 fix: Complete OIDC RP-Initiated Logout With id_token_hint and Redirect Race Fix (#12024)

* fix: complete OIDC logout implementation

The OIDC logout feature added in #5626 was incomplete:

1. Backend: Missing id_token_hint/client_id parameters required by the
   RP-Initiated Logout spec. Keycloak 18+ rejects logout without these.

2. Frontend: The logout redirect URL was passed through isSafeRedirect()
   which rejects all absolute URLs. The redirect was silently dropped.

Backend: Add id_token_hint (preferred) or client_id (fallback) to the
logout URL for OIDC spec compliance.

Frontend: Use window.location.replace() for logout redirects from the
backend, bypassing isSafeRedirect() which was designed for user-input
validation.

Fixes #5506

* fix: accept undefined in setTokenHeader to properly clear Authorization header

When token is undefined, delete the Authorization header instead of
setting it to "Bearer undefined". Removes the @ts-ignore workaround
in AuthContext.

* fix: skip axios 401 refresh when Authorization header is cleared

When the Authorization header has been removed (e.g. during logout),
the response interceptor now skips the token refresh flow. This
prevents a successful refresh from canceling an in-progress OIDC
external redirect via window.location.replace().

* fix: guard against undefined OPENID_CLIENT_ID in logout URL

Prevent literal "client_id=undefined" in the OIDC end-session URL
when OPENID_CLIENT_ID is not set. Log a warning when neither
id_token_hint nor client_id is available.

* fix: prevent race condition canceling OIDC logout redirect

The logout mutation wrapper's cleanup (clearStates, removeQueries)
triggers re-renders and 401s on in-flight requests. The axios
interceptor would refresh the token successfully, firing
dispatchTokenUpdatedEvent which cancels the window.location.replace()
navigation to the IdP's end_session_endpoint.

Fix:
- Clear Authorization header synchronously before redirect so the
  axios interceptor skips refresh for post-logout 401s
- Add isExternalRedirectRef to suppress silentRefresh and useEffect
  side effects during the redirect
- Add JSDoc explaining why isSafeRedirect is bypassed

* test: add LogoutController and AuthContext logout test coverage

LogoutController.spec.js (13 tests):
- id_token_hint from session and cookie fallback
- client_id fallback, including undefined OPENID_CLIENT_ID guard
- Disabled endpoint, missing issuer, non-OpenID user
- post_logout_redirect_uri (custom and default)
- Missing OpenID config and end_session_endpoint
- Error handling and cookie clearing

AuthContext.spec.tsx (3 tests):
- OIDC redirect calls window.location.replace + setTokenHeader
- Non-redirect logout path
- Logout error handling

* test: add coverage for setTokenHeader, axios interceptor guard, and silentRefresh suppression

headers-helpers.spec.ts (3 tests):
- Sets Authorization header with Bearer token
- Deletes Authorization header when called with undefined
- No-op when clearing an already absent header

request-interceptor.spec.ts (2 tests):
- Skips refresh when Authorization header is cleared (the race fix)
- Attempts refresh when Authorization header is present

AuthContext.spec.tsx (1 new test):
- Verifies silentRefresh is not triggered after OIDC redirect

* test: enhance request-interceptor tests with adapter restoration and refresh verification

- Store the original axios adapter before tests and restore it after all tests to prevent side effects.
- Add verification for the refresh endpoint call in the interceptor tests to ensure correct behavior during token refresh attempts.

* test: enhance AuthContext tests with live rendering and improved logout error handling

- Introduced a new `renderProviderLive` function to facilitate testing with silentRefresh.
- Updated tests to use the live rendering function, ensuring accurate simulation of authentication behavior.
- Enhanced logout error handling test to verify that auth state is cleared without external redirects.

* test: update LogoutController tests for OpenID config error handling

- Renamed test suite to clarify that it handles cases when OpenID config is not available.
- Modified test to check for error thrown by getOpenIdConfig instead of returning null, ensuring proper logging of the error message.

* refactor: improve OpenID config error handling in LogoutController

- Simplified error handling for OpenID configuration retrieval by using a try-catch block.
- Updated logging to provide clearer messages when the OpenID config is unavailable.
- Ensured that the end session endpoint is only accessed if the OpenID config is successfully retrieved.

---------

Co-authored-by: cloudspinner <stijn.tastenhoye@gmail.com>

api/server/controllers/auth/LogoutController.spec.js

@@ -0,0 +1,259 @@
+const cookies = require('cookie');
+
+const mockLogoutUser = jest.fn();
+const mockLogger = { warn: jest.fn(), error: jest.fn() };
+const mockIsEnabled = jest.fn();
+const mockGetOpenIdConfig = jest.fn();
+
+jest.mock('cookie');
+jest.mock('@librechat/api', () => ({ isEnabled: (...args) => mockIsEnabled(...args) }));
+jest.mock('@librechat/data-schemas', () => ({ logger: mockLogger }));
+jest.mock('~/server/services/AuthService', () => ({
+  logoutUser: (...args) => mockLogoutUser(...args),
+}));
+jest.mock('~/strategies', () => ({ getOpenIdConfig: () => mockGetOpenIdConfig() }));
+
+const { logoutController } = require('./LogoutController');
+
+function buildReq(overrides = {}) {
+  return {
+    user: { _id: 'user1', openidId: 'oid1', provider: 'openid' },
+    headers: { cookie: 'refreshToken=rt1' },
+    session: {
+      openidTokens: { refreshToken: 'srt', idToken: 'small-id-token' },
+      destroy: jest.fn(),
+    },
+    ...overrides,
+  };
+}
+
+function buildRes() {
+  const res = {
+    status: jest.fn().mockReturnThis(),
+    send: jest.fn().mockReturnThis(),
+    json: jest.fn().mockReturnThis(),
+    clearCookie: jest.fn(),
+  };
+  return res;
+}
+
+const ORIGINAL_ENV = process.env;
+
+beforeEach(() => {
+  jest.clearAllMocks();
+  process.env = {
+    ...ORIGINAL_ENV,
+    OPENID_USE_END_SESSION_ENDPOINT: 'true',
+    OPENID_ISSUER: 'https://idp.example.com',
+    OPENID_CLIENT_ID: 'my-client-id',
+    DOMAIN_CLIENT: 'https://app.example.com',
+  };
+  cookies.parse.mockReturnValue({ refreshToken: 'cookie-rt' });
+  mockLogoutUser.mockResolvedValue({ status: 200, message: 'Logout successful' });
+  mockIsEnabled.mockReturnValue(true);
+  mockGetOpenIdConfig.mockReturnValue({
+    serverMetadata: () => ({
+      end_session_endpoint: 'https://idp.example.com/logout',
+    }),
+  });
+});
+
+afterAll(() => {
+  process.env = ORIGINAL_ENV;
+});
+
+describe('LogoutController', () => {
+  describe('id_token_hint from session', () => {
+    it('sets id_token_hint when session has idToken', async () => {
+      const req = buildReq();
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      const body = res.send.mock.calls[0][0];
+      expect(body.redirect).toContain('id_token_hint=small-id-token');
+      expect(body.redirect).not.toContain('client_id=');
+    });
+  });
+
+  describe('id_token_hint from cookie fallback', () => {
+    it('uses cookie id_token when session has no tokens', async () => {
+      cookies.parse.mockReturnValue({
+        refreshToken: 'cookie-rt',
+        openid_id_token: 'cookie-id-token',
+      });
+      const req = buildReq({ session: { destroy: jest.fn() } });
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      const body = res.send.mock.calls[0][0];
+      expect(body.redirect).toContain('id_token_hint=cookie-id-token');
+    });
+  });
+
+  describe('client_id fallback', () => {
+    it('falls back to client_id when no idToken is available', async () => {
+      cookies.parse.mockReturnValue({ refreshToken: 'cookie-rt' });
+      const req = buildReq({ session: { destroy: jest.fn() } });
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      const body = res.send.mock.calls[0][0];
+      expect(body.redirect).toContain('client_id=my-client-id');
+      expect(body.redirect).not.toContain('id_token_hint=');
+    });
+
+    it('does not produce client_id=undefined when OPENID_CLIENT_ID is unset', async () => {
+      delete process.env.OPENID_CLIENT_ID;
+      cookies.parse.mockReturnValue({ refreshToken: 'cookie-rt' });
+      const req = buildReq({ session: { destroy: jest.fn() } });
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      const body = res.send.mock.calls[0][0];
+      expect(body.redirect).not.toContain('client_id=');
+      expect(body.redirect).not.toContain('undefined');
+      expect(mockLogger.warn).toHaveBeenCalledWith(
+        expect.stringContaining('Neither id_token_hint nor OPENID_CLIENT_ID'),
+      );
+    });
+  });
+
+  describe('OPENID_USE_END_SESSION_ENDPOINT disabled', () => {
+    it('does not include redirect when disabled', async () => {
+      mockIsEnabled.mockReturnValue(false);
+      const req = buildReq();
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      const body = res.send.mock.calls[0][0];
+      expect(body.redirect).toBeUndefined();
+    });
+  });
+
+  describe('OPENID_ISSUER unset', () => {
+    it('does not include redirect when OPENID_ISSUER is missing', async () => {
+      delete process.env.OPENID_ISSUER;
+      const req = buildReq();
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      const body = res.send.mock.calls[0][0];
+      expect(body.redirect).toBeUndefined();
+    });
+  });
+
+  describe('non-OpenID user', () => {
+    it('does not include redirect for non-OpenID users', async () => {
+      const req = buildReq({
+        user: { _id: 'user1', provider: 'local' },
+      });
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      const body = res.send.mock.calls[0][0];
+      expect(body.redirect).toBeUndefined();
+    });
+  });
+
+  describe('post_logout_redirect_uri', () => {
+    it('uses OPENID_POST_LOGOUT_REDIRECT_URI when set', async () => {
+      process.env.OPENID_POST_LOGOUT_REDIRECT_URI = 'https://custom.example.com/logged-out';
+      const req = buildReq();
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      const body = res.send.mock.calls[0][0];
+      const url = new URL(body.redirect);
+      expect(url.searchParams.get('post_logout_redirect_uri')).toBe(
+        'https://custom.example.com/logged-out',
+      );
+    });
+
+    it('defaults to DOMAIN_CLIENT/login when OPENID_POST_LOGOUT_REDIRECT_URI is unset', async () => {
+      delete process.env.OPENID_POST_LOGOUT_REDIRECT_URI;
+      const req = buildReq();
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      const body = res.send.mock.calls[0][0];
+      const url = new URL(body.redirect);
+      expect(url.searchParams.get('post_logout_redirect_uri')).toBe(
+        'https://app.example.com/login',
+      );
+    });
+  });
+
+  describe('OpenID config not available', () => {
+    it('warns and returns no redirect when getOpenIdConfig throws', async () => {
+      mockGetOpenIdConfig.mockImplementation(() => {
+        throw new Error('OpenID configuration has not been initialized');
+      });
+      const req = buildReq();
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      const body = res.send.mock.calls[0][0];
+      expect(body.redirect).toBeUndefined();
+      expect(mockLogger.warn).toHaveBeenCalledWith(
+        expect.stringContaining('OpenID config not available'),
+        'OpenID configuration has not been initialized',
+      );
+    });
+  });
+
+  describe('end_session_endpoint not in metadata', () => {
+    it('warns and returns no redirect when end_session_endpoint is missing', async () => {
+      mockGetOpenIdConfig.mockReturnValue({
+        serverMetadata: () => ({}),
+      });
+      const req = buildReq();
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      const body = res.send.mock.calls[0][0];
+      expect(body.redirect).toBeUndefined();
+      expect(mockLogger.warn).toHaveBeenCalledWith(
+        expect.stringContaining('end_session_endpoint not found'),
+      );
+    });
+  });
+
+  describe('error handling', () => {
+    it('returns 500 on logoutUser error', async () => {
+      mockLogoutUser.mockRejectedValue(new Error('session error'));
+      const req = buildReq();
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      expect(res.status).toHaveBeenCalledWith(500);
+      expect(res.json).toHaveBeenCalledWith({ message: 'session error' });
+    });
+  });
+
+  describe('cookie clearing', () => {
+    it('clears all auth cookies on successful logout', async () => {
+      const req = buildReq();
+      const res = buildRes();
+
+      await logoutController(req, res);
+
+      expect(res.clearCookie).toHaveBeenCalledWith('refreshToken');
+      expect(res.clearCookie).toHaveBeenCalledWith('openid_access_token');
+      expect(res.clearCookie).toHaveBeenCalledWith('openid_id_token');
+      expect(res.clearCookie).toHaveBeenCalledWith('openid_user_id');
+      expect(res.clearCookie).toHaveBeenCalledWith('token_provider');
+    });
+  });
+});