fix: move implementation to "internal" package

internal/handler/middleware/security_headers.go

@@ -0,0 +1,40 @@
+package middleware
+
+import (
+	"net/http"
+
+	"spend-sparrow/internal/types"
+)
+
+func SecurityHeaders(serverSettings *types.Settings) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("X-Content-Type-Options", "nosniff")
+			w.Header().Set("Access-Control-Allow-Origin", serverSettings.BaseUrl)
+			w.Header().Set("Access-Control-Allow-Methods", "GET, POST, DELETE")
+			w.Header().Set("Content-Security-Policy",
+				"default-src 'none'; "+
+					"script-src 'self'; "+
+					"font-src 'self'; "+
+					"connect-src 'self'; "+
+					"img-src 'self'; "+
+					"style-src 'self'; "+
+					"form-action 'self'; "+
+					"frame-ancestors 'none'; ",
+			)
+			w.Header().Set("Cross-Origin-Resource-Policy", "same-origin")
+			w.Header().Set("Cross-Origin-Opener-Policy", "same-origin")
+			w.Header().Set("Cross-Origin-Embedder-Policy", "require-corp")
+			w.Header().Set("Permissions-Policy", "geolocation=(), camera=(), microphone=(), interest-cohort=()")
+			w.Header().Set("Referrer-Policy", "strict-origin-when-cross-origin")
+			w.Header().Set("Strict-Transport-Security", "max-age=63072000; includeSubDomains; preload")
+
+			if r.Method == http.MethodOptions {
+				w.WriteHeader(http.StatusOK)
+				return
+			}
+
+			next.ServeHTTP(w, r)
+		})
+	}
+}