gnu-social/plugins/Embed/Embed.php
2021-09-14 13:12:51 +01:00

485 lines
18 KiB
PHP

<?php
// {{{ License
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// GNU social is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with GNU social. If not, see <http://www.gnu.org/licenses/>.
// }}}
/**
* 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 <mail@diogo.site>
* @authir Hugo Sales <hugo@hsal.es>
*
* @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(<<<END
<article class="h-entry embed">
<header>
<img class="u-photo embed" width="{{attributes['width']}}" height="{{attributes['height']}}" src="{{attributes['src']}}" />
<h5 class="p-name embed">
<a class="u-url" href="{{attachment.getUrl()}}">{{embed.getTitle() | escape}}</a>
</h5>
<div class="p-author embed">
{% if embed.getAuthorName() is not null %}
<div class="fn vcard author">
{% if embed.getAuthorUrl() is null %}
<p>{{embed.getAuthorName()}}</p>
{% else %}
<a href="{{embed.getAuthorUrl()}}" class="url">{{embed.getAuthorName()}}</a>
{% endif %}
</div>
{% endif %}
{% if embed.getProvider() is not null %}
<div class="fn vcard">
{% if embed.getProviderUrl() is null %}
<p>{{embed.getProvider()}}</p>
{% else %}
<a href="{{embed.getProviderUrl()}}" class="url">{{embed.getProvider()}}</a>
{% endif %}
</div>
{% endif %}
</div>
</header>
<div class="p-summary embed">
{{ embed.getHtml() | escape }}
</div>
</article>
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;
}
}