Phred/src/Http/Middleware/Security/SecureHeadersMiddleware.php

<?php
declare(strict_types=1);

namespace Phred\Http\Middleware\Security;

use Phred\Http\Middleware\Middleware;
use Phred\Support\Contracts\ConfigInterface;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\RequestHandlerInterface;

/**
 * Middleware to add common security headers to the response.
 */
final class SecureHeadersMiddleware extends Middleware
{
    public function __construct(
        private readonly ConfigInterface $config
    ) {}

    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
    {
        $response = $this->profile($request, $handler);

        // Standard security headers
        $response = $response->withHeader('X-Content-Type-Options', 'nosniff')
            ->withHeader('X-Frame-Options', 'SAMEORIGIN')
            ->withHeader('X-XSS-Protection', '1; mode=block')
            ->withHeader('Referrer-Policy', 'no-referrer-when-downgrade')
            ->withHeader('Content-Security-Policy', $this->config->get('security.csp', "default-src 'self'"));

        if ($this->config->get('security.hsts', true)) {
            $response = $response->withHeader('Strict-Transport-Security', 'max-age=31536000; includeSubDomains');
        }

        return $response;
    }
}