feat(backend): 提交后端审计修复与配套测试改动

backend/internal/server/middleware/api_key_auth.go

@@ -96,7 +96,7 @@ func apiKeyAuthWithSubscription(apiKeyService *service.APIKeyService, subscripti
 		// 检查 IP 限制（白名单/黑名单）
 		// 注意：错误信息故意模糊，避免暴露具体的 IP 限制机制
 		if len(apiKey.IPWhitelist) > 0 || len(apiKey.IPBlacklist) > 0 {
-			clientIP := ip.GetClientIP(c)
+			clientIP := ip.GetTrustedClientIP(c)
 			allowed, _ := ip.CheckIPRestriction(clientIP, apiKey.IPWhitelist, apiKey.IPBlacklist)
 			if !allowed {
 				AbortWithError(c, 403, "ACCESS_DENIED", "Access denied")

backend/internal/server/middleware/api_key_auth_test.go

@@ -300,6 +300,57 @@ func TestAPIKeyAuthOverwritesInvalidContextGroup(t *testing.T) {
 	require.Equal(t, http.StatusOK, w.Code)
 }
 
+func TestAPIKeyAuthIPRestrictionDoesNotTrustSpoofedForwardHeaders(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	user := &service.User{
+		ID:          7,
+		Role:        service.RoleUser,
+		Status:      service.StatusActive,
+		Balance:     10,
+		Concurrency: 3,
+	}
+	apiKey := &service.APIKey{
+		ID:          100,
+		UserID:      user.ID,
+		Key:         "test-key",
+		Status:      service.StatusActive,
+		User:        user,
+		IPWhitelist: []string{"1.2.3.4"},
+	}
+
+	apiKeyRepo := &stubApiKeyRepo{
+		getByKey: func(ctx context.Context, key string) (*service.APIKey, error) {
+			if key != apiKey.Key {
+				return nil, service.ErrAPIKeyNotFound
+			}
+			clone := *apiKey
+			return &clone, nil
+		},
+	}
+
+	cfg := &config.Config{RunMode: config.RunModeSimple}
+	apiKeyService := service.NewAPIKeyService(apiKeyRepo, nil, nil, nil, nil, nil, cfg)
+	router := gin.New()
+	require.NoError(t, router.SetTrustedProxies(nil))
+	router.Use(gin.HandlerFunc(NewAPIKeyAuthMiddleware(apiKeyService, nil, cfg)))
+	router.GET("/t", func(c *gin.Context) {
+		c.JSON(http.StatusOK, gin.H{"ok": true})
+	})
+
+	w := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/t", nil)
+	req.RemoteAddr = "9.9.9.9:12345"
+	req.Header.Set("x-api-key", apiKey.Key)
+	req.Header.Set("X-Forwarded-For", "1.2.3.4")
+	req.Header.Set("X-Real-IP", "1.2.3.4")
+	req.Header.Set("CF-Connecting-IP", "1.2.3.4")
+	router.ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusForbidden, w.Code)
+	require.Contains(t, w.Body.String(), "ACCESS_DENIED")
+}
+
 func newAuthTestRouter(apiKeyService *service.APIKeyService, subscriptionService *service.SubscriptionService, cfg *config.Config) *gin.Engine {
 	router := gin.New()
 	router.Use(gin.HandlerFunc(NewAPIKeyAuthMiddleware(apiKeyService, subscriptionService, cfg)))