function RedirectResponseSubscriber::checkRedirectUrl

Allows manipulation of the response object when performing a redirect.

Parameters

\Symfony\Component\HttpKernel\Event\ResponseEvent $event: The Event to process.

File

core/lib/Drupal/Core/EventSubscriber/RedirectResponseSubscriber.php, line 53

Class

RedirectResponseSubscriber
Allows manipulation of the response object when performing a redirect.

Namespace

Drupal\Core\EventSubscriber

Code

public function checkRedirectUrl(ResponseEvent $event) {
  $response = $event->getResponse();
  if ($response instanceof RedirectResponse) {
    $request = $event->getRequest();
    // Let the 'destination' query parameter override the redirect target.
    // If $response is already a SecuredRedirectResponse, it might reject the
    // new target as invalid, in which case proceed with the old target.
    $destination = $request->query
      ->get('destination');
    if ($destination && !$this->ignoreDestination) {
      // The 'Location' HTTP header must always be absolute.
      $destination = $this->getDestinationAsAbsoluteUrl($destination, $request->getSchemeAndHttpHost());
      try {
        $response->setTargetUrl($destination);
      } catch (\InvalidArgumentException $e) {
      }
    }
    // Regardless of whether the target is the original one or the overridden
    // destination, ensure that all redirects are safe.
    if (!$response instanceof SecuredRedirectResponse) {
      try {
        // SecuredRedirectResponse is an abstract class that requires a
        // concrete implementation. Default to LocalRedirectResponse, which
        // considers only redirects to within the same site as safe.
        $safe_response = LocalRedirectResponse::createFromRedirectResponse($response);
        $safe_response->setRequestContext($this->requestContext);
      } catch (\InvalidArgumentException $e) {
        // If the above failed, it's because the redirect target wasn't
        // local. Do not follow that redirect. Log an error message instead,
        // then return a 400 response to the client with the error message.
        // We don't throw an exception, because this is a client error rather
        // than a server error.
        $message = 'Redirects to external URLs are not allowed by default, use \\Drupal\\Core\\Routing\\TrustedRedirectResponse for it.';
        /** @var \Psr\Log\LoggerInterface $logger */
        $logger = ($this->loggerClosure)();
        $logger->error($message);
        $safe_response = new Response($message, 400);
      }
      $event->setResponse($safe_response);
    }
  }
}

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