fix: restrict CORS to configured origins (closes #40)

- Add CORSOrigins config field (UPAAS_CORS_ORIGINS env var)
- Default to same-origin only (no CORS headers when unconfigured)
- When configured, allow specified origins with AllowCredentials: true
- Add tests for CORS middleware behavior

internal/config/config.go

@@ -52,6 +52,7 @@ type Config struct {
 	MetricsUsername string
 	MetricsPassword string
 	SessionSecret   string
+	CORSOrigins     string
 	params          *Params
 	log             *slog.Logger
 }
@@ -102,6 +103,7 @@ func setupViper(name string) {
 	viper.SetDefault("METRICS_USERNAME", "")
 	viper.SetDefault("METRICS_PASSWORD", "")
 	viper.SetDefault("SESSION_SECRET", "")
+	viper.SetDefault("CORS_ORIGINS", "")
 }
 
 func buildConfig(log *slog.Logger, params *Params) (*Config, error) {
@@ -136,6 +138,7 @@ func buildConfig(log *slog.Logger, params *Params) (*Config, error) {
 		MetricsUsername: viper.GetString("METRICS_USERNAME"),
 		MetricsPassword: viper.GetString("METRICS_PASSWORD"),
 		SessionSecret:   viper.GetString("SESSION_SECRET"),
+		CORSOrigins:     viper.GetString("CORS_ORIGINS"),
 		params:          params,
 		log:             log,
 	}

internal/middleware/cors_test.go

@@ -11,6 +11,7 @@ import (
 	"git.eeqj.de/sneak/upaas/internal/config"
 )
 
+//nolint:gosec // test credentials
 func newCORSTestMiddleware(corsOrigins string) *Middleware {
 	return &Middleware{
 		log: slog.Default(),
@@ -24,6 +25,8 @@ func newCORSTestMiddleware(corsOrigins string) *Middleware {
 }
 
 func TestCORS_NoOriginsConfigured_NoCORSHeaders(t *testing.T) {
+	t.Parallel()
+
 	m := newCORSTestMiddleware("")
 	handler := m.CORS()(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 		w.WriteHeader(http.StatusOK)
@@ -31,6 +34,7 @@ func TestCORS_NoOriginsConfigured_NoCORSHeaders(t *testing.T) {
 
 	req := httptest.NewRequest(http.MethodGet, "/", nil)
 	req.Header.Set("Origin", "https://evil.com")
+
 	rec := httptest.NewRecorder()
 	handler.ServeHTTP(rec, req)
 
@@ -39,6 +43,8 @@ func TestCORS_NoOriginsConfigured_NoCORSHeaders(t *testing.T) {
 }
 
 func TestCORS_OriginsConfigured_AllowsMatchingOrigin(t *testing.T) {
+	t.Parallel()
+
 	m := newCORSTestMiddleware("https://app.example.com,https://other.example.com")
 	handler := m.CORS()(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 		w.WriteHeader(http.StatusOK)
@@ -46,6 +52,7 @@ func TestCORS_OriginsConfigured_AllowsMatchingOrigin(t *testing.T) {
 
 	req := httptest.NewRequest(http.MethodGet, "/", nil)
 	req.Header.Set("Origin", "https://app.example.com")
+
 	rec := httptest.NewRecorder()
 	handler.ServeHTTP(rec, req)
 
@@ -56,6 +63,8 @@ func TestCORS_OriginsConfigured_AllowsMatchingOrigin(t *testing.T) {
 }
 
 func TestCORS_OriginsConfigured_RejectsNonMatchingOrigin(t *testing.T) {
+	t.Parallel()
+
 	m := newCORSTestMiddleware("https://app.example.com")
 	handler := m.CORS()(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 		w.WriteHeader(http.StatusOK)
@@ -63,6 +72,7 @@ func TestCORS_OriginsConfigured_RejectsNonMatchingOrigin(t *testing.T) {
 
 	req := httptest.NewRequest(http.MethodGet, "/", nil)
 	req.Header.Set("Origin", "https://evil.com")
+
 	rec := httptest.NewRecorder()
 	handler.ServeHTTP(rec, req)
 

internal/middleware/middleware.go

@@ -177,17 +177,48 @@ func realIP(r *http.Request) string {
 }
 
 // CORS returns CORS middleware.
+// When UPAAS_CORS_ORIGINS is empty (default), no CORS headers are sent
+// (same-origin only). When configured, only the specified origins are
+// allowed and credentials (cookies) are permitted.
 func (m *Middleware) CORS() func(http.Handler) http.Handler {
+	origins := parseCORSOrigins(m.params.Config.CORSOrigins)
+
+	// No origins configured — no CORS headers (same-origin policy).
+	if len(origins) == 0 {
+		return func(next http.Handler) http.Handler {
+			return next
+		}
+	}
+
 	return cors.Handler(cors.Options{
-		AllowedOrigins:   []string{"*"},
+		AllowedOrigins:   origins,
 		AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
 		AllowedHeaders:   []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token"},
 		ExposedHeaders:   []string{"Link"},
-		AllowCredentials: false,
+		AllowCredentials: true,
 		MaxAge:           corsMaxAge,
 	})
 }
 
+// parseCORSOrigins splits a comma-separated origin string into a slice,
+// trimming whitespace. Returns nil if the input is empty.
+func parseCORSOrigins(raw string) []string {
+	if raw == "" {
+		return nil
+	}
+
+	parts := strings.Split(raw, ",")
+	origins := make([]string, 0, len(parts))
+
+	for _, p := range parts {
+		if o := strings.TrimSpace(p); o != "" {
+			origins = append(origins, o)
+		}
+	}
+
+	return origins
+}
+
 // MetricsAuth returns basic auth middleware for metrics endpoint.
 func (m *Middleware) MetricsAuth() func(http.Handler) http.Handler {
 	if m.params.Config.MetricsUsername == "" {
@@ -235,9 +266,9 @@ func (m *Middleware) CSRF() func(http.Handler) http.Handler {
 // loginRateLimit configures the login rate limiter.
 const (
 	loginRateLimit      = rate.Limit(5.0 / 60.0) // 5 requests per 60 seconds
-	loginBurst          = 5                       // allow burst of 5
+	loginBurst          = 5                      // allow burst of 5
-	limiterExpiry       = 10 * time.Minute        // evict entries not seen in 10 minutes
+	limiterExpiry       = 10 * time.Minute       // evict entries not seen in 10 minutes
-	limiterCleanupEvery = 1 * time.Minute         // sweep interval
+	limiterCleanupEvery = 1 * time.Minute        // sweep interval
 )
 
 // ipLimiterEntry stores a rate limiter with its last-seen timestamp.
@@ -249,8 +280,8 @@ type ipLimiterEntry struct {
 // ipLimiter tracks per-IP rate limiters for login attempts with automatic
 // eviction of stale entries to prevent unbounded memory growth.
 type ipLimiter struct {
-	mu       sync.Mutex
+	mu        sync.Mutex
-	limiters map[string]*ipLimiterEntry
+	limiters  map[string]*ipLimiterEntry
 	lastSweep time.Time
 }
 

internal/models/app.go

@@ -32,23 +32,23 @@ const (
 type App struct {
 	db *database.Database
 
-	ID             string
+	ID                string
-	Name           string
+	Name              string
-	RepoURL        string
+	RepoURL           string
-	Branch         string
+	Branch            string
-	DockerfilePath string
+	DockerfilePath    string
 	WebhookSecret     string
 	WebhookSecretHash string
 	SSHPrivateKey     string
-	SSHPublicKey   string
+	SSHPublicKey      string
-	ImageID         sql.NullString
+	ImageID           sql.NullString
-	PreviousImageID sql.NullString
+	PreviousImageID   sql.NullString
-	Status          AppStatus
+	Status            AppStatus
-	DockerNetwork  sql.NullString
+	DockerNetwork     sql.NullString
-	NtfyTopic      sql.NullString
+	NtfyTopic         sql.NullString
-	SlackWebhook   sql.NullString
+	SlackWebhook      sql.NullString
-	CreatedAt      time.Time
+	CreatedAt         time.Time
-	UpdatedAt      time.Time
+	UpdatedAt         time.Time
 }
 
 // NewApp creates a new App with a database reference.

internal/server/routes.go

@@ -54,51 +54,51 @@ func (s *Server) SetupRoutes() {
 		r.Group(func(r chi.Router) {
 			r.Use(s.mw.SessionAuth())
 
-		// Dashboard
+			// Dashboard
-		r.Get("/", s.handlers.HandleDashboard())
+			r.Get("/", s.handlers.HandleDashboard())
 
-		// Logout
+			// Logout
-		r.Post("/logout", s.handlers.HandleLogout())
+			r.Post("/logout", s.handlers.HandleLogout())
 
-		// App routes
+			// App routes
-		r.Get("/apps/new", s.handlers.HandleAppNew())
+			r.Get("/apps/new", s.handlers.HandleAppNew())
-		r.Post("/apps", s.handlers.HandleAppCreate())
+			r.Post("/apps", s.handlers.HandleAppCreate())
-		r.Get("/apps/{id}", s.handlers.HandleAppDetail())
+			r.Get("/apps/{id}", s.handlers.HandleAppDetail())
-		r.Get("/apps/{id}/edit", s.handlers.HandleAppEdit())
+			r.Get("/apps/{id}/edit", s.handlers.HandleAppEdit())
-		r.Post("/apps/{id}", s.handlers.HandleAppUpdate())
+			r.Post("/apps/{id}", s.handlers.HandleAppUpdate())
-		r.Post("/apps/{id}/delete", s.handlers.HandleAppDelete())
+			r.Post("/apps/{id}/delete", s.handlers.HandleAppDelete())
-		r.Post("/apps/{id}/deploy", s.handlers.HandleAppDeploy())
+			r.Post("/apps/{id}/deploy", s.handlers.HandleAppDeploy())
-		r.Post("/apps/{id}/deployments/cancel", s.handlers.HandleCancelDeploy())
+			r.Post("/apps/{id}/deployments/cancel", s.handlers.HandleCancelDeploy())
-		r.Get("/apps/{id}/deployments", s.handlers.HandleAppDeployments())
+			r.Get("/apps/{id}/deployments", s.handlers.HandleAppDeployments())
-		r.Get("/apps/{id}/deployments/{deploymentID}/logs", s.handlers.HandleDeploymentLogsAPI())
+			r.Get("/apps/{id}/deployments/{deploymentID}/logs", s.handlers.HandleDeploymentLogsAPI())
-		r.Get("/apps/{id}/deployments/{deploymentID}/download", s.handlers.HandleDeploymentLogDownload())
+			r.Get("/apps/{id}/deployments/{deploymentID}/download", s.handlers.HandleDeploymentLogDownload())
-		r.Get("/apps/{id}/logs", s.handlers.HandleAppLogs())
+			r.Get("/apps/{id}/logs", s.handlers.HandleAppLogs())
-		r.Get("/apps/{id}/container-logs", s.handlers.HandleContainerLogsAPI())
+			r.Get("/apps/{id}/container-logs", s.handlers.HandleContainerLogsAPI())
-		r.Get("/apps/{id}/status", s.handlers.HandleAppStatusAPI())
+			r.Get("/apps/{id}/status", s.handlers.HandleAppStatusAPI())
-		r.Get("/apps/{id}/recent-deployments", s.handlers.HandleRecentDeploymentsAPI())
+			r.Get("/apps/{id}/recent-deployments", s.handlers.HandleRecentDeploymentsAPI())
-		r.Post("/apps/{id}/rollback", s.handlers.HandleAppRollback())
+			r.Post("/apps/{id}/rollback", s.handlers.HandleAppRollback())
-		r.Post("/apps/{id}/restart", s.handlers.HandleAppRestart())
+			r.Post("/apps/{id}/restart", s.handlers.HandleAppRestart())
-		r.Post("/apps/{id}/stop", s.handlers.HandleAppStop())
+			r.Post("/apps/{id}/stop", s.handlers.HandleAppStop())
-		r.Post("/apps/{id}/start", s.handlers.HandleAppStart())
+			r.Post("/apps/{id}/start", s.handlers.HandleAppStart())
 
-		// Environment variables
+			// Environment variables
-		r.Post("/apps/{id}/env-vars", s.handlers.HandleEnvVarAdd())
+			r.Post("/apps/{id}/env-vars", s.handlers.HandleEnvVarAdd())
-		r.Post("/apps/{id}/env-vars/{varID}/edit", s.handlers.HandleEnvVarEdit())
+			r.Post("/apps/{id}/env-vars/{varID}/edit", s.handlers.HandleEnvVarEdit())
-		r.Post("/apps/{id}/env-vars/{varID}/delete", s.handlers.HandleEnvVarDelete())
+			r.Post("/apps/{id}/env-vars/{varID}/delete", s.handlers.HandleEnvVarDelete())
 
-		// Labels
+			// Labels
-		r.Post("/apps/{id}/labels", s.handlers.HandleLabelAdd())
+			r.Post("/apps/{id}/labels", s.handlers.HandleLabelAdd())
-		r.Post("/apps/{id}/labels/{labelID}/edit", s.handlers.HandleLabelEdit())
+			r.Post("/apps/{id}/labels/{labelID}/edit", s.handlers.HandleLabelEdit())
-		r.Post("/apps/{id}/labels/{labelID}/delete", s.handlers.HandleLabelDelete())
+			r.Post("/apps/{id}/labels/{labelID}/delete", s.handlers.HandleLabelDelete())
 
-		// Volumes
+			// Volumes
-		r.Post("/apps/{id}/volumes", s.handlers.HandleVolumeAdd())
+			r.Post("/apps/{id}/volumes", s.handlers.HandleVolumeAdd())
-		r.Post("/apps/{id}/volumes/{volumeID}/edit", s.handlers.HandleVolumeEdit())
+			r.Post("/apps/{id}/volumes/{volumeID}/edit", s.handlers.HandleVolumeEdit())
-		r.Post("/apps/{id}/volumes/{volumeID}/delete", s.handlers.HandleVolumeDelete())
+			r.Post("/apps/{id}/volumes/{volumeID}/delete", s.handlers.HandleVolumeDelete())
 
-		// Ports
+			// Ports
-		r.Post("/apps/{id}/ports", s.handlers.HandlePortAdd())
+			r.Post("/apps/{id}/ports", s.handlers.HandlePortAdd())
-		r.Post("/apps/{id}/ports/{portID}/delete", s.handlers.HandlePortDelete())
+			r.Post("/apps/{id}/ports/{portID}/delete", s.handlers.HandlePortDelete())
 		})
 	})
 

internal/service/deploy/deploy.go

@@ -82,7 +82,7 @@ type deploymentLogWriter struct {
 	lineBuffer bytes.Buffer // buffer for incomplete lines
 	mu         sync.Mutex
 	done       chan struct{}
-	flushed    sync.WaitGroup // waits for flush goroutine to finish
+	flushed    sync.WaitGroup  // waits for flush goroutine to finish
 	flushCtx   context.Context //nolint:containedctx // needed for async flush goroutine
 }