internal/api/middleware/security.go

package middleware

import (
	"strings"

	"github.com/gin-gonic/gin"
)

func SecurityHeaders() gin.HandlerFunc {
	return func(c *gin.Context) {
		// Prevent clickjacking
		c.Header("X-Frame-Options", "DENY")

		// Prevent MIME type sniffing
		c.Header("X-Content-Type-Options", "nosniff")

		// XSS Protection
		c.Header("X-XSS-Protection", "1; mode=block")

		// Referrer Policy
		c.Header("Referrer-Policy", "strict-origin-when-cross-origin")

		// Permissions Policy
		c.Header("Permissions-Policy", "geolocation=(), microphone=(), camera=()")

		// HSTS (HTTPS only)
		c.Header("Strict-Transport-Security", "max-age=31536000; includeSubDomains; preload")

		// CSP for API (restrictive)
		if !strings.HasPrefix(c.Request.URL.Path, "/management") {
			c.Header("Content-Security-Policy", "default-src 'none'")
		}

		c.Next()
	}
}

// CSP for Management UI
func ManagementCSP() gin.HandlerFunc {
	return func(c *gin.Context) {
		csp := strings.Join([]string{
			"default-src 'self'",
			"script-src 'self' 'unsafe-inline' 'unsafe-eval'",
			"style-src 'self' 'unsafe-inline'",
			"img-src 'self' data: https:",
			"font-src 'self'",
			"connect-src 'self'",
			"frame-ancestors 'none'",
			"base-uri 'self'",
			"form-action 'self'",
		}, "; ")

		c.Header("Content-Security-Policy", csp)
		c.Next()
	}
}