Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\image\Controller;
Chris@0: 
Chris@0: use Drupal\Component\Utility\Crypt;
Chris@0: use Drupal\Core\Image\ImageFactory;
Chris@0: use Drupal\Core\Lock\LockBackendInterface;
Chris@0: use Drupal\image\ImageStyleInterface;
Chris@0: use Drupal\system\FileDownloadController;
Chris@0: use Symfony\Component\DependencyInjection\ContainerInterface;
Chris@0: use Symfony\Component\HttpFoundation\BinaryFileResponse;
Chris@0: use Symfony\Component\HttpFoundation\Request;
Chris@0: use Symfony\Component\HttpFoundation\Response;
Chris@16: use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
Chris@0: use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
Chris@0: use Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException;
Chris@0: 
Chris@0: /**
Chris@0:  * Defines a controller to serve image styles.
Chris@0:  */
Chris@0: class ImageStyleDownloadController extends FileDownloadController {
Chris@0: 
Chris@0:   /**
Chris@0:    * The lock backend.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Lock\LockBackendInterface
Chris@0:    */
Chris@0:   protected $lock;
Chris@0: 
Chris@0:   /**
Chris@0:    * The image factory.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Image\ImageFactory
Chris@0:    */
Chris@0:   protected $imageFactory;
Chris@0: 
Chris@0:   /**
Chris@0:    * A logger instance.
Chris@0:    *
Chris@0:    * @var \Psr\Log\LoggerInterface
Chris@0:    */
Chris@0:   protected $logger;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a ImageStyleDownloadController object.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Lock\LockBackendInterface $lock
Chris@0:    *   The lock backend.
Chris@0:    * @param \Drupal\Core\Image\ImageFactory $image_factory
Chris@0:    *   The image factory.
Chris@0:    */
Chris@0:   public function __construct(LockBackendInterface $lock, ImageFactory $image_factory) {
Chris@0:     $this->lock = $lock;
Chris@0:     $this->imageFactory = $image_factory;
Chris@0:     $this->logger = $this->getLogger('image');
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public static function create(ContainerInterface $container) {
Chris@0:     return new static(
Chris@0:       $container->get('lock'),
Chris@0:       $container->get('image.factory')
Chris@0:     );
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Generates a derivative, given a style and image path.
Chris@0:    *
Chris@0:    * After generating an image, transfer it to the requesting agent.
Chris@0:    *
Chris@0:    * @param \Symfony\Component\HttpFoundation\Request $request
Chris@0:    *   The request object.
Chris@0:    * @param string $scheme
Chris@0:    *   The file scheme, defaults to 'private'.
Chris@0:    * @param \Drupal\image\ImageStyleInterface $image_style
Chris@0:    *   The image style to deliver.
Chris@0:    *
Chris@0:    * @return \Symfony\Component\HttpFoundation\BinaryFileResponse|\Symfony\Component\HttpFoundation\Response
Chris@0:    *   The transferred file as response or some error response.
Chris@0:    *
Chris@16:    * @throws \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
Chris@16:    *   Thrown when the file request is invalid.
Chris@0:    * @throws \Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException
Chris@0:    *   Thrown when the user does not have access to the file.
Chris@0:    * @throws \Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException
Chris@0:    *   Thrown when the file is still being generated.
Chris@0:    */
Chris@0:   public function deliver(Request $request, $scheme, ImageStyleInterface $image_style) {
Chris@0:     $target = $request->query->get('file');
Chris@0:     $image_uri = $scheme . '://' . $target;
Chris@0: 
Chris@0:     // Check that the style is defined, the scheme is valid, and the image
Chris@0:     // derivative token is valid. Sites which require image derivatives to be
Chris@0:     // generated without a token can set the
Chris@0:     // 'image.settings:allow_insecure_derivatives' configuration to TRUE to
Chris@0:     // bypass the latter check, but this will increase the site's vulnerability
Chris@0:     // to denial-of-service attacks. To prevent this variable from leaving the
Chris@0:     // site vulnerable to the most serious attacks, a token is always required
Chris@0:     // when a derivative of a style is requested.
Chris@0:     // The $target variable for a derivative of a style has
Chris@0:     // styles/<style_name>/... as structure, so we check if the $target variable
Chris@0:     // starts with styles/.
Chris@0:     $valid = !empty($image_style) && file_stream_wrapper_valid_scheme($scheme);
Chris@0:     if (!$this->config('image.settings')->get('allow_insecure_derivatives') || strpos(ltrim($target, '\/'), 'styles/') === 0) {
Chris@0:       $valid &= $request->query->get(IMAGE_DERIVATIVE_TOKEN) === $image_style->getPathToken($image_uri);
Chris@0:     }
Chris@0:     if (!$valid) {
Chris@16:       // Return a 404 (Page Not Found) rather than a 403 (Access Denied) as the
Chris@16:       // image token is for DDoS protection rather than access checking. 404s
Chris@16:       // are more likely to be cached (e.g. at a proxy) which enhances
Chris@16:       // protection from DDoS.
Chris@16:       throw new NotFoundHttpException();
Chris@0:     }
Chris@0: 
Chris@0:     $derivative_uri = $image_style->buildUri($image_uri);
Chris@0:     $headers = [];
Chris@0: 
Chris@0:     // If using the private scheme, let other modules provide headers and
Chris@0:     // control access to the file.
Chris@0:     if ($scheme == 'private') {
Chris@0:       $headers = $this->moduleHandler()->invokeAll('file_download', [$image_uri]);
Chris@0:       if (in_array(-1, $headers) || empty($headers)) {
Chris@0:         throw new AccessDeniedHttpException();
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     // Don't try to generate file if source is missing.
Chris@0:     if (!file_exists($image_uri)) {
Chris@0:       // If the image style converted the extension, it has been added to the
Chris@0:       // original file, resulting in filenames like image.png.jpeg. So to find
Chris@0:       // the actual source image, we remove the extension and check if that
Chris@0:       // image exists.
Chris@0:       $path_info = pathinfo($image_uri);
Chris@0:       $converted_image_uri = $path_info['dirname'] . DIRECTORY_SEPARATOR . $path_info['filename'];
Chris@0:       if (!file_exists($converted_image_uri)) {
Chris@0:         $this->logger->notice('Source image at %source_image_path not found while trying to generate derivative image at %derivative_path.', ['%source_image_path' => $image_uri, '%derivative_path' => $derivative_uri]);
Chris@0:         return new Response($this->t('Error generating image, missing source file.'), 404);
Chris@0:       }
Chris@0:       else {
Chris@0:         // The converted file does exist, use it as the source.
Chris@0:         $image_uri = $converted_image_uri;
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     // Don't start generating the image if the derivative already exists or if
Chris@0:     // generation is in progress in another thread.
Chris@0:     if (!file_exists($derivative_uri)) {
Chris@0:       $lock_name = 'image_style_deliver:' . $image_style->id() . ':' . Crypt::hashBase64($image_uri);
Chris@0:       $lock_acquired = $this->lock->acquire($lock_name);
Chris@0:       if (!$lock_acquired) {
Chris@0:         // Tell client to retry again in 3 seconds. Currently no browsers are
Chris@0:         // known to support Retry-After.
Chris@0:         throw new ServiceUnavailableHttpException(3, $this->t('Image generation in progress. Try again shortly.'));
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     // Try to generate the image, unless another thread just did it while we
Chris@0:     // were acquiring the lock.
Chris@0:     $success = file_exists($derivative_uri) || $image_style->createDerivative($image_uri, $derivative_uri);
Chris@0: 
Chris@0:     if (!empty($lock_acquired)) {
Chris@0:       $this->lock->release($lock_name);
Chris@0:     }
Chris@0: 
Chris@0:     if ($success) {
Chris@0:       $image = $this->imageFactory->get($derivative_uri);
Chris@0:       $uri = $image->getSource();
Chris@0:       $headers += [
Chris@0:         'Content-Type' => $image->getMimeType(),
Chris@0:         'Content-Length' => $image->getFileSize(),
Chris@0:       ];
Chris@0:       // \Drupal\Core\EventSubscriber\FinishResponseSubscriber::onRespond()
Chris@0:       // sets response as not cacheable if the Cache-Control header is not
Chris@0:       // already modified. We pass in FALSE for non-private schemes for the
Chris@0:       // $public parameter to make sure we don't change the headers.
Chris@0:       return new BinaryFileResponse($uri, 200, $headers, $scheme !== 'private');
Chris@0:     }
Chris@0:     else {
Chris@0:       $this->logger->notice('Unable to generate the derived image located at %path.', ['%path' => $derivative_uri]);
Chris@0:       return new Response($this->t('Error generating image.'), 500);
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0: }