. // }}} /** * OEmbed and OpenGraph implementation for GNU social * * @package GNUsocial * * @author Mikael Nordfeldth * @author Stephen Paul Weber * @author hannes * @author Mikael Nordfeldth * @author Miguel Dantas * @author Diogo Peralta Cordeiro * @authir Hugo Sales * * @copyright 2014-2021 Free Software Foundation, Inc http://www.fsf.org * @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later */ namespace Plugin\Embed; use App\Core\Cache; use App\Core\DB\DB; use App\Core\Event; use App\Core\GSFile; use App\Core\HTTPClient; use App\Core\Log; use App\Core\Modules\Plugin; use App\Core\Router\RouteLoader; use App\Core\Router\Router; use App\Core\Security; use App\Entity\Attachment; use App\Entity\AttachmentThumbnail; use App\Util\Common; use App\Util\Exception\DuplicateFoundException; use App\Util\Exception\NotFoundException; use App\Util\TemporaryFile; use Embed\Embed as LibEmbed; use Symfony\Component\HttpFoundation\Request; /** * Base class for the Embed plugin that does most of the heavy lifting to get * and display representations for remote content. * * @copyright 2014-2021 Free Software Foundation, Inc http://www.fsf.org * @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later */ class Embed extends Plugin { /** * Settings which can be set in social.local.yaml * WARNING, these are _regexps_ (slashes added later). Always escape your dots and end ('$') your strings */ public $domain_allowlist = [ // hostname => service provider '.*' => '', // Default to allowing any host ]; /** * This code executes when GNU social creates the page routing, and we hook * on this event to add our action handler for Embed. * * @param $m URLMapper the router that was initialized. * * @throws Exception * * @return void true if successful, the exception object if it isn't. */ public function onAddRoute(RouteLoader $m) { $m->connect('oembed', 'main/oembed', Controller\Embed::class); $m->connect('embed', 'main/embed', Controller\Embed::class); return Event::next; } /** * Insert oembed and opengraph tags in all HTML head elements */ public function onShowHeadElements(Request $request, array $result) { $matches = []; preg_match(',/?([^/]+)/?.*,', $request->getPathInfo(), $matches); switch ($matches[1]) { case 'attachment': $url = "{$matches[1]}/{$matches[2]}"; break; } if (isset($url)) { foreach (['xml', 'json'] as $format) { $result[] = [ 'link' => [ 'rel' => 'alternate', 'type' => "application/{$format}+oembed", 'href' => Router::url('embed', ['format' => $format, 'url' => $url]), 'title' => 'oEmbed', ], ]; } } return Event::next; } /** * Save embedding information for an Attachment, if applicable. * * Normally this event is called through File::saveNew() * * @param Attachment $attachment The newly inserted Attachment object. * * @return bool success */ public function onAttachmentStoreNew(Attachment $attachment) { try { DB::findOneBy('attachment_embed', ['attachment_id' => $attachment->getId()]); } catch (NotFoundException) { } catch (DuplicateFoundException) { Log::warning("Strangely, an attachment_embed object exists for new file {$attachment->getID()}"); return Event::next; } if (!is_null($attachment->getRemoteUrl()) || (!is_null($mimetype = $attachment->getMimetype()) && (('text/html' === substr($mimetype, 0, 9) || 'application/xhtml+xml' === substr($mimetype, 0, 21))))) { try { $embed_data = $this->getEmbed($attachment->getRemoteUrl(), $attachment); $embed_data['attachment_id'] = $attachment->getId(); DB::persist(Entity\AttachmentEmbed::create($embed_data)); DB::flush(); } catch (Exception $e) { Log::warning($e); return Event::next; } } return Event::next; } /** * Replace enclosure representation of an attachment with the data from embed * * @param mixed $enclosure */ public function onFileEnclosureMetadata(Attachment $attachment, &$enclosure) { // Never treat generic HTML links as an enclosure type! // But if we have embed info, we'll consider it golden. try { $embed = DB::findOneBy('attachment_embed', ['attachment_id' => $attachment->getId()]); } catch (NotFoundException) { return Event::next; } foreach (['mimetype', 'url', 'title', 'modified', 'width', 'height'] as $key) { if (isset($embed->{$key}) && !empty($embed->{$key})) { $enclosure->{$key} = $embed->{$key}; } } return true; } /** Placeholder */ public function onShowAttachment(Attachment $attachment, array &$res) { try { $embed = Cache::get('attachment-embed-' . $attachment->getId(), fn () => DB::findOneBy('attachment_embed', ['attachment_id' => $attachment->getId()])); } catch (DuplicateFoundException $e) { Log::waring($e); return Event::next; } catch (NotFoundException) { return Event::next; } if (is_null($embed) && empty($embed->getAuthorName()) && empty($embed->getProvider())) { return Event::next; } $thumbnail = AttachmentThumbnail::getOrCreate(attachment: $attachment, width: $width, height: $height, crop: $smart_crop); $attributes = $thumbnail->getHTMLAttributes(['class' => 'u-photo embed']); $res[] = Formatting::twigRender(<<
{{embed.getTitle() | escape}}
{% if embed.getAuthorName() is not null %}
{% if embed.getAuthorUrl() is null %}

{{embed.getAuthorName()}}

{% else %} {{embed.getAuthorName()}} {% endif %}
{% endif %} {% if embed.getProvider() is not null %}
{% if embed.getProviderUrl() is null %}

{{embed.getProvider()}}

{% else %} {{embed.getProvider()}} {% endif %}
{% endif %}
{{ embed.getHtml() | escape }}
END, ['embed' => $embed, 'thumbnail' => $thumbnail, 'attributes' => $attributes]); return Event::stop; } /** * @throws ServerException if check is made but fails * * @return bool false on no check made, provider name on success */ protected function checkAllowlist(string $url) { if ($this->check_allowlist ?? false) { return false; // indicates "no check made" } $host = parse_url($url, PHP_URL_HOST); foreach ($this->domain_allowlist as $regex => $provider) { if (preg_match("/{$regex}/", $host)) { return $provider; // we trust this source, return provider name } } throw new ServerException(_m('Domain not in remote thumbnail source allowlist: {host}', ['host' => $host])); } /** * Check the file size of a remote file using a HEAD request and checking * the content-length variable returned. This isn't 100% foolproof but is * reliable enough for our purposes. * * @param string $url * @param array $headers - if we already made a request * * @return bool|string the file size if it succeeds, false otherwise. */ private function getRemoteFileSize(string $url, ?array $headers = null): ?int { try { if ($headers === null) { if (!Common::isValidHttpUrl($url)) { Log::error('Invalid URL in Embed::getRemoteFileSize()'); return false; } $head = HTTPClient::head($url); $headers = $head->getHeaders(); $headers = array_change_key_case($headers, CASE_LOWER); } return $headers['content-length'][0] ?? false; } catch (Exception $e) { Loog::error($e); return false; } } /** * A private helper function that uses a HEAD request to check the mime type * of a remote URL to see it it's an image. * * @param mixed $url * @param null|mixed $headers * * @return bool true if the remote URL is an image, or false otherwise. */ private function isRemoteImage(string $url, ?array $headers = null): ?int { try { if ($headers === null) { if (!Common::isValidHttpUrl($url)) { Log::error('Invalid URL in Embed::getRemoteFileSize()'); return false; } $head = HTTPClient::head($url); $headers = $head->getHeaders(); $headers = array_change_key_case($headers, CASE_LOWER); } return !empty($headers['content-type']) && GSFile::mimetypeMajor($headers['content-type'][0]) === 'image'; } catch (Exception $e) { Loog::error($e); return false; } } /** * Validate that $imgData is a valid image, place it in it's folder and resize * * @param $imgData - The image data to validate * @param null|string $url - The url where the image came from, to fetch metadata * @param null|array $headers - The headers possible previous request to $url */ protected function validateAndWriteImage($imgData, string $url, array $headers): array { $file = new TemporaryFile(); $file->write($imgData); $mimetype = $headers['content-type'][0]; Event::handle('AttachmentValidation', [&$file, &$mimetype]); Event::handle('HashFile', [$file->getPathname(), &$hash]); $filename = Common::config('attachments', 'dir') . "embed/{$hash}"; $file->commit($filename); unset($file); if (array_key_exists('content-disposition', $headers) && preg_match('/^.+; filename="(.+?)"$/', $headers['content-disposition'][0], $matches) === 1) { $original_name = $matches[1]; } $info = getimagesize($filename); $width = $info[0]; $height = $info[1]; return [$filename, $width, $height, $original_name ?? null, $mimetype]; } /** * Create and store a thumbnail representation of a remote image */ protected function storeRemoteThumbnail(Attachment $attachment): array | bool { if ($attachment->haveFilename() && file_exists($attachment->getPath())) { throw new AlreadyFulfilledException(_m('A thumbnail seems to already exist for remote file with id=={id}', ['id' => $attachment->getId()])); } $url = $attachment->getRemoteUrl(); if (substr($url, 0, 7) == 'file://') { $filename = substr($url, 7); $info = getimagesize($filename); $filename = basename($filename); $width = $info[0]; $height = $info[1]; } else { $this->checkAllowlist($url); $head = HTTPClient::head($url); $headers = $head->getHeaders(); $headers = array_change_key_case($headers, CASE_LOWER); try { $is_image = $this->isRemoteImage($url, $headers); if ($is_image == true) { $file_size = $this->getRemoteFileSize($url, $headers); $max_size = Common::config('attachments', 'file_quota'); if (($file_size != false) && ($file_size > $max_size)) { throw new \Exception("Wanted to store remote thumbnail of size {$file_size} but the upload limit is {$max_size} so we aborted."); } } else { return false; } } catch (Exception $err) { Log::debug('Could not determine size of remote image, aborted local storage.'); throw $err; } // First we download the file to memory and test whether it's actually an image file Log::debug('Downloading remote thumbnail for file id==' . $attachment->getId() . " with thumbnail URL: {$url}"); try { $imgData = HTTPClient::get($url)->getContent(); if (isset($imgData)) { [$filename, $width, $height, $original_name, $mimetype] = $this->validateAndWriteImage($imgData, $url, $headers); } else { throw new UnsupportedMediaException(_m('HTTPClient returned an empty result')); } } catch (UnsupportedMediaException $e) { // Couldn't find anything that looks like an image, nothing to do Log::debug($e); return false; } } DB::persist(AttachmentThumbnail::create(['attachment_id' => $attachment->getId(), 'width' => $width, 'height' => $height])); $attachment->setFilename($filename); DB::flush(); return [$filename, $width, $height, $original_name, $mimetype]; } /** * Perform an oEmbed or OpenGraph lookup for the given $url. * * Some known hosts are allowlisted with API endpoints where we * know they exist but autodiscovery data isn't available. * * Throws exceptions on failure. * * @param string $url * * @throws EmbedHelper_BadHtmlException * @throws HTTP_Request2_Exception * * @return object */ public function getEmbed(string $url, Attachment $attachment): array { Log::info('Checking for remote URL metadata for ' . $url); try { Log::info("Trying to find Embed data for {$url} with 'oscarotero/Embed'"); $embed = new LibEmbed(); $info = $embed->get($url); $metadata['title'] = $info->title; $metadata['html'] = Security::sanitize($info->description); $metadata['url'] = $info->url; $metadata['author_name'] = $info->authorName; $metadata['author_url'] = $info->authorUrl; $metadata['provider_name'] = $info->providerName; $metadata['provider_url'] = $info->providerUrl; if (!is_null($info->image)) { if (substr($info->image, 0, 4) === 'data') { // Inline image $imgData = base64_decode(substr($info->image, stripos($info->image, 'base64,') + 7)); [$filename, $width, $height, $original_name, $mimetype] = $this->validateAndWriteImage($imgData); } else { $attachment->setRemoteUrl((string) $info->image); [$filename, $width, $height, $original_name, $mimetype] = $this->storeRemoteThumbnail($attachment); } $metadata['width'] = $height; $metadata['height'] = $width; $metadata['mimetype'] = $mimetype; } } catch (Exception $e) { Log::info("Failed to find Embed data for {$url} with 'oscarotero/Embed', got exception: " . get_class($e)); } $metadata = self::normalize($metadata); $attachment->setTitle($metadata['title']); return $metadata; } /** * Normalize fetched info. */ public static function normalize(array $data): array { if (isset($metadata['url'])) { // sometimes sites serve the path, not the full URL, for images // let's "be liberal in what you accept from others"! // add protocol and host if the thumbnail_url starts with / if ($metadata['url'][0] == '/') { $thumbnail_url_parsed = parse_url($metadata['url']); $metadata['url'] = "{$thumbnail_url_parsed['scheme']}://{$thumbnail_url_parsed['host']}{$metadata['url']}"; } // Some wordpress opengraph implementations sometimes return a white blank image // no need for us to save that! if ($metadata['url'] == 'https://s0.wp.com/i/blank.jpg') { $metadata['url'] = null; } if (!isset($data['width'])) { $data['width'] = Common::config('thumbnail', 'width'); $data['height'] = Common::config('thumbnail', 'height'); } } return $data; } }