fix login error

backend/src/app.ts

@@ -8,6 +8,9 @@ import { errorHandler, notFoundHandler } from './middleware/error.middleware';
 
 const app: Application = express();
 
+// Trust proxy (required for correct IP detection behind Traefik/Nginx)
+app.set('trust proxy', 1);
+
 // Security middleware
 app.use(helmet());
 
@@ -17,7 +20,7 @@ app.use(cors({
   credentials: true,
 }));
 
-// Rate limiting
+// Rate limiting - general API routes
 const limiter = rateLimit({
   windowMs: environment.rateLimit.windowMs,
   max: environment.rateLimit.max,
@@ -26,6 +29,16 @@ const limiter = rateLimit({
   legacyHeaders: false,
 });
 
+// Rate limiting - auth routes (more generous to avoid blocking logins)
+const authLimiter = rateLimit({
+  windowMs: 15 * 60 * 1000, // 15 minutes
+  max: 30, // 30 auth attempts per window
+  message: 'Zu viele Anmeldeversuche. Bitte versuchen Sie es später erneut.',
+  standardHeaders: true,
+  legacyHeaders: false,
+});
+
+app.use('/api/auth', authLimiter);
 app.use('/api', limiter);
 
 // Body parsing middleware

frontend/src/components/auth/LoginCallback.tsx

@@ -34,10 +34,13 @@ const LoginCallback: React.FC = () => {
         navigate('/dashboard', { replace: true });
       } catch (err) {
         console.error('Login callback error:', err);
+        const is429 = err && typeof err === 'object' && 'status' in err && (err as any).status === 429;
         setError(
-          err instanceof Error
-            ? err.message
-            : 'Anmeldung fehlgeschlagen. Bitte versuchen Sie es erneut.'
+          is429
+            ? 'Zu viele Anmeldeversuche. Bitte warten Sie einige Minuten und versuchen Sie es erneut.'
+            : err instanceof Error
+              ? err.message
+              : 'Anmeldung fehlgeschlagen. Bitte versuchen Sie es erneut.'
         );
       }
     };

frontend/src/contexts/AuthContext.tsx

@@ -91,7 +91,12 @@ export const AuthProvider: React.FC<AuthProviderProps> = ({ children }) => {
       });
 
       // Show error notification
-      notification.showError('Anmeldung fehlgeschlagen. Bitte versuchen Sie es erneut.');
+      const is429 = error && typeof error === 'object' && 'status' in error && (error as any).status === 429;
+      notification.showError(
+        is429
+          ? 'Zu viele Anmeldeversuche. Bitte warten Sie einige Minuten und versuchen Sie es erneut.'
+          : 'Anmeldung fehlgeschlagen. Bitte versuchen Sie es erneut.'
+      );
       throw error;
     }
   }, [notification]);

frontend/src/services/api.ts

@@ -38,7 +38,7 @@ class ApiService {
     // Response interceptor: Handle errors
     this.axiosInstance.interceptors.response.use(
       (response) => response,
-      (error: AxiosError) => {
+      async (error: AxiosError) => {
         if (error.response?.status === 401) {
           // Clear tokens and redirect to login
           console.warn('Unauthorized request, redirecting to login');
@@ -46,6 +46,22 @@ class ApiService {
           removeUser();
           window.location.href = '/login';
         }
+
+        // Retry on 429 (Too Many Requests) with exponential backoff
+        if (error.response?.status === 429 && error.config) {
+          const config = error.config as AxiosRequestConfig & { _retryCount?: number };
+          const retryCount = config._retryCount || 0;
+          const maxRetries = 3;
+
+          if (retryCount < maxRetries) {
+            config._retryCount = retryCount + 1;
+            const delay = Math.pow(2, retryCount) * 1000; // 1s, 2s, 4s
+            console.warn(`Rate limited (429). Retrying in ${delay}ms (attempt ${retryCount + 1}/${maxRetries})...`);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+            return this.axiosInstance.request(config);
+          }
+        }
+
         return Promise.reject(this.handleError(error));
       }
     );