BlackholeMiddleware.php

BlackholeMiddleware.php

<?php

declare(strict_types=1);

namespace App\Http\Middleware;

use Cake\Core\Exception\CakeException;
use Cake\Core\InstanceConfigTrait;
use Cake\Http\Response;
use Cake\Log\Log;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\MiddlewareInterface;
use Psr\Http\Server\RequestHandlerInterface;

class BlackholeMiddleware implements MiddlewareInterface
{
    use InstanceConfigTrait;

    /**
     * Configuration options.
     *
     * @var array<string, mixed>
     */
    protected array $_defaultConfig = [
    ];

    /**
     * The amount of time to cache the asset.
     *
     * @var string
     */
    protected string $cacheTime = '+1 day';

    /**
     * Constructor.
     *
     * @param array<string, mixed> $options The options to use
     */
    public function __construct(array $options = [])
    {
        if (!empty($options['cacheTime'])) {
            $this->cacheTime = $options['cacheTime'];
        }
    }

    /**
     * @param \Psr\Http\Message\ServerRequestInterface $request The request.
     * @param \Psr\Http\Server\RequestHandlerInterface $handler The request handler.
     *
     * @return \Psr\Http\Message\ResponseInterface A response.
     */
    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
    {
        if ($this->isBlackholed($request)) {
            Log::write('debug', 'BlackholeMiddleware: blackholed ' . env('REMOTE_ADDR'));

            return $this->respond();
        }

        return $handler->handle($request);
    }

    /**
     * @param \Psr\Http\Message\ServerRequestInterface $request
     *
     * @return bool
     */
    protected function isBlackholed(ServerRequestInterface $request): bool
    {
        $list = [
            '...',
        ];
        $ip = env('REMOTE_ADDR');
        if (in_array($ip, $list, true)) {
            return true;
        }

        return false;
    }

    /**
     * Respond with the 403 code.
     *
     * @throws \Cake\Core\Exception\CakeException
     *
     * @return \Psr\Http\Message\ResponseInterface
     */
    protected function respond(): ResponseInterface
    {
        $expire = strtotime($this->cacheTime);
        if ($expire === false) {
            throw new CakeException(sprintf('Invalid cache time value `%s`', $this->cacheTime));
        }
        $maxAge = $expire - time();

        $message = 'Spam bot or malicious (crawler) request';

        $response = new Response();
        $body = $response->getBody();
        $body->write($message);
        $body->rewind();

        return $response
            ->withStatus(403, $message)
            ->withHeader('Cache-Control', 'public,max-age=' . $maxAge)
            ->withHeader('Date', gmdate(DATE_RFC7231, time()))
            ->withHeader('Expires', gmdate(DATE_RFC7231, $expire));
    }
}