Enhance security architecture and guidelines across documentation and middleware; implement input validation, logging improvements, and security headers in API handlers.

go_cloud/internal/middleware/middleware.go

@@ -25,6 +25,27 @@ var RequestID = middleware.RequestID
 var Logger = middleware.Logger
 var Recoverer = middleware.Recoverer
 
+// SecurityHeaders adds security-related HTTP headers
+func SecurityHeaders() func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			// Prevent MIME type sniffing
+			w.Header().Set("X-Content-Type-Options", "nosniff")
+			// Prevent clickjacking - allow for WOPI routes
+			if !strings.HasPrefix(r.URL.Path, "/wopi") && !strings.HasPrefix(r.URL.Path, "/user/files/") && !strings.HasPrefix(r.URL.Path, "/orgs/") {
+				w.Header().Set("X-Frame-Options", "DENY")
+			}
+			// Enable XSS protection
+			w.Header().Set("X-XSS-Protection", "1; mode=block")
+			// Referrer policy
+			w.Header().Set("Referrer-Policy", "strict-origin-when-cross-origin")
+			// Content Security Policy - basic policy
+			w.Header().Set("Content-Security-Policy", "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self' data:; connect-src 'self' https://go.b0esche.cloud https://of.b0esche.cloud; frame-src 'self' https://of.b0esche.cloud;")
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
 // CORS middleware - accepts allowedOrigins comma-separated string
 func CORS(allowedOrigins string) func(http.Handler) http.Handler {
 	allowedList, allowAll := compileAllowedOrigins(allowedOrigins)