3 namespace Drupal\image\Controller;
5 use Drupal\Component\Utility\Crypt;
6 use Drupal\Core\Image\ImageFactory;
7 use Drupal\Core\Lock\LockBackendInterface;
8 use Drupal\image\ImageStyleInterface;
9 use Drupal\system\FileDownloadController;
10 use Symfony\Component\DependencyInjection\ContainerInterface;
11 use Symfony\Component\HttpFoundation\BinaryFileResponse;
12 use Symfony\Component\HttpFoundation\Request;
13 use Symfony\Component\HttpFoundation\Response;
14 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
15 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
16 use Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException;
19 * Defines a controller to serve image styles.
21 class ImageStyleDownloadController extends FileDownloadController {
26 * @var \Drupal\Core\Lock\LockBackendInterface
33 * @var \Drupal\Core\Image\ImageFactory
35 protected $imageFactory;
40 * @var \Psr\Log\LoggerInterface
45 * Constructs a ImageStyleDownloadController object.
47 * @param \Drupal\Core\Lock\LockBackendInterface $lock
49 * @param \Drupal\Core\Image\ImageFactory $image_factory
52 public function __construct(LockBackendInterface $lock, ImageFactory $image_factory) {
54 $this->imageFactory = $image_factory;
55 $this->logger = $this->getLogger('image');
61 public static function create(ContainerInterface $container) {
63 $container->get('lock'),
64 $container->get('image.factory')
69 * Generates a derivative, given a style and image path.
71 * After generating an image, transfer it to the requesting agent.
73 * @param \Symfony\Component\HttpFoundation\Request $request
75 * @param string $scheme
76 * The file scheme, defaults to 'private'.
77 * @param \Drupal\image\ImageStyleInterface $image_style
78 * The image style to deliver.
80 * @return \Symfony\Component\HttpFoundation\BinaryFileResponse|\Symfony\Component\HttpFoundation\Response
81 * The transferred file as response or some error response.
83 * @throws \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
84 * Thrown when the file request is invalid.
85 * @throws \Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException
86 * Thrown when the user does not have access to the file.
87 * @throws \Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException
88 * Thrown when the file is still being generated.
90 public function deliver(Request $request, $scheme, ImageStyleInterface $image_style) {
91 $target = $request->query->get('file');
92 $image_uri = $scheme . '://' . $target;
94 // Check that the style is defined, the scheme is valid, and the image
95 // derivative token is valid. Sites which require image derivatives to be
96 // generated without a token can set the
97 // 'image.settings:allow_insecure_derivatives' configuration to TRUE to
98 // bypass the latter check, but this will increase the site's vulnerability
99 // to denial-of-service attacks. To prevent this variable from leaving the
100 // site vulnerable to the most serious attacks, a token is always required
101 // when a derivative of a style is requested.
102 // The $target variable for a derivative of a style has
103 // styles/<style_name>/... as structure, so we check if the $target variable
104 // starts with styles/.
105 $valid = !empty($image_style) && file_stream_wrapper_valid_scheme($scheme);
106 if (!$this->config('image.settings')->get('allow_insecure_derivatives') || strpos(ltrim($target, '\/'), 'styles/') === 0) {
107 $valid &= $request->query->get(IMAGE_DERIVATIVE_TOKEN) === $image_style->getPathToken($image_uri);
110 // Return a 404 (Page Not Found) rather than a 403 (Access Denied) as the
111 // image token is for DDoS protection rather than access checking. 404s
112 // are more likely to be cached (e.g. at a proxy) which enhances
113 // protection from DDoS.
114 throw new NotFoundHttpException();
117 $derivative_uri = $image_style->buildUri($image_uri);
120 // If using the private scheme, let other modules provide headers and
121 // control access to the file.
122 if ($scheme == 'private') {
123 $headers = $this->moduleHandler()->invokeAll('file_download', [$image_uri]);
124 if (in_array(-1, $headers) || empty($headers)) {
125 throw new AccessDeniedHttpException();
129 // Don't try to generate file if source is missing.
130 if (!file_exists($image_uri)) {
131 // If the image style converted the extension, it has been added to the
132 // original file, resulting in filenames like image.png.jpeg. So to find
133 // the actual source image, we remove the extension and check if that
135 $path_info = pathinfo($image_uri);
136 $converted_image_uri = $path_info['dirname'] . DIRECTORY_SEPARATOR . $path_info['filename'];
137 if (!file_exists($converted_image_uri)) {
138 $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' => $derivative_uri]);
139 return new Response($this->t('Error generating image, missing source file.'), 404);
142 // The converted file does exist, use it as the source.
143 $image_uri = $converted_image_uri;
147 // Don't start generating the image if the derivative already exists or if
148 // generation is in progress in another thread.
149 if (!file_exists($derivative_uri)) {
150 $lock_name = 'image_style_deliver:' . $image_style->id() . ':' . Crypt::hashBase64($image_uri);
151 $lock_acquired = $this->lock->acquire($lock_name);
152 if (!$lock_acquired) {
153 // Tell client to retry again in 3 seconds. Currently no browsers are
154 // known to support Retry-After.
155 throw new ServiceUnavailableHttpException(3, $this->t('Image generation in progress. Try again shortly.'));
159 // Try to generate the image, unless another thread just did it while we
160 // were acquiring the lock.
161 $success = file_exists($derivative_uri) || $image_style->createDerivative($image_uri, $derivative_uri);
163 if (!empty($lock_acquired)) {
164 $this->lock->release($lock_name);
168 $image = $this->imageFactory->get($derivative_uri);
169 $uri = $image->getSource();
171 'Content-Type' => $image->getMimeType(),
172 'Content-Length' => $image->getFileSize(),
174 // \Drupal\Core\EventSubscriber\FinishResponseSubscriber::onRespond()
175 // sets response as not cacheable if the Cache-Control header is not
176 // already modified. We pass in FALSE for non-private schemes for the
177 // $public parameter to make sure we don't change the headers.
178 return new BinaryFileResponse($uri, 200, $headers, $scheme !== 'private');
181 $this->logger->notice('Unable to generate the derived image located at %path.', ['%path' => $derivative_uri]);
182 return new Response($this->t('Error generating image.'), 500);