StoreRemoteMedia now checks remote filesize before downloading

This commit is contained in:
Mikael Nordfeldth 2016-06-24 15:56:14 +02:00
parent 7d67eefdf5
commit 948744538c

View File

@ -15,6 +15,11 @@ class StoreRemoteMediaPlugin extends Plugin
public $append_whitelist = array(); // fill this array as domain_whitelist to add more trusted sources public $append_whitelist = array(); // fill this array as domain_whitelist to add more trusted sources
public $check_whitelist = false; // security/abuse precaution public $check_whitelist = false; // security/abuse precaution
public $domain_blacklist = array();
public $check_blacklist = false;
public $max_image_bytes = 10485760; // 10MiB max image size by default
protected $imgData = array(); protected $imgData = array();
// these should be declared protected everywhere // these should be declared protected everywhere
@ -50,7 +55,7 @@ class StoreRemoteMediaPlugin extends Plugin
switch (common_get_mime_media($file->mimetype)) { switch (common_get_mime_media($file->mimetype)) {
case 'image': case 'image':
// Just to set something for now at least... // Just to set something for now at least...
$file->title = $file->mimetype; //$file->title = $file->mimetype;
break; break;
} }
@ -74,19 +79,53 @@ class StoreRemoteMediaPlugin extends Plugin
return true; return true;
} }
$this->checkWhitelist($file->getUrl()); $remoteUrl = $file->getUrl();
if (!$this->checkWhiteList($remoteUrl) ||
!$this->checkBlackList($remoteUrl)) {
return true;
}
// First we download the file to memory and test whether it's actually an image file
common_debug(sprintf('Downloading remote file id==%u with URL: %s', $file->getID(), _ve($file->getUrl())));
try { try {
$imgData = HTTPClient::quickGet($file->getUrl()); /*
$http = new HTTPClient();
common_debug(sprintf('Performing HEAD request for remote file id==%u to avoid unnecessarily downloading too large files. URL: %s', $file->getID(), $remoteUrl));
$head = $http->head($remoteUrl);
$remoteUrl = $head->getEffectiveUrl(); // to avoid going through redirects again
if (!$this->checkBlackList($remoteUrl)) {
common_log(LOG_WARN, sprintf('%s: Non-blacklisted URL %s redirected to blacklisted URL %s', __CLASS__, $file->getUrl(), $remoteUrl));
return true;
}
$headers = $head->getHeader();
$filesize = isset($headers['content-length']) ? $headers['content-length'] : null;
*/
$filesize = $file->getSize();
if (empty($filesize)) {
// file size not specified on remote server
common_debug(sprintf('%s: Ignoring remote media because we did not get a content length for file id==%u', __CLASS__, $file->getID()));
return true;
} elseif ($filesize > $this->max_image_bytes) {
//FIXME: When we perhaps start fetching videos etc. we'll need to differentiate max_image_bytes from that...
// file too big according to plugin configuration
common_debug(sprintf('%s: Skipping remote media because content length (%u) is larger than plugin configured max_image_bytes (%u) for file id==%u', __CLASS__, intval($filesize), $this->max_image_bytes, $file->getID()));
return true;
} elseif ($filesize > common_config('attachments', 'file_quota')) {
// file too big according to site configuration
common_debug(sprintf('%s: Skipping remote media because content length (%u) is larger than file_quota (%u) for file id==%u', __CLASS__, intval($filesize), common_config('attachments', 'file_quota'), $file->getID()));
return true;
}
// Then we download the file to memory and test whether it's actually an image file
common_debug(sprintf('Downloading remote file id==%u (should be size %u) with effective URL: %s', $file->getID(), $filesize, _ve($remoteUrl)));
$imgData = HTTPClient::quickGet($remoteUrl);
} catch (HTTP_Request2_ConnectionException $e) { } catch (HTTP_Request2_ConnectionException $e) {
common_log(LOG_ERR, __CLASS__.': quickGet on URL: '._ve($file->getUrl()).' threw exception: '.$e->getMessage()); common_log(LOG_ERR, __CLASS__.': '._ve(get_class($e)).' on URL: '._ve($file->getUrl()).' threw exception: '.$e->getMessage());
return true; return true;
} }
$info = @getimagesizefromstring($imgData); $info = @getimagesizefromstring($imgData);
if ($info === false) { if ($info === false) {
throw new UnsupportedMediaException(_('Remote file format was not identified as an image.'), $file->getUrl()); throw new UnsupportedMediaException(_('Remote file format was not identified as an image.'), $remoteUrl);
} elseif (!$info[0] || !$info[1]) { } elseif (!$info[0] || !$info[1]) {
throw new UnsupportedMediaException(_('Image file had impossible geometry (0 width or height)')); throw new UnsupportedMediaException(_('Image file had impossible geometry (0 width or height)'));
} }
@ -124,23 +163,39 @@ class StoreRemoteMediaPlugin extends Plugin
} }
/** /**
* @return boolean false on no check made, provider name on success * @return boolean true if given url passes blacklist check
* @throws ServerException if check is made but fails
*/ */
protected function checkWhitelist($url) protected function checkBlackList($url)
{ {
if (!$this->check_whitelist) { if (!$this->check_blacklist) {
return false; // indicates "no check made" return true;
} }
$host = parse_url($url, PHP_URL_HOST); $host = parse_url($url, PHP_URL_HOST);
foreach ($this->domain_whitelist as $regex => $provider) { foreach ($this->domain_blacklist as $regex => $provider) {
if (preg_match("/$regex/", $host)) { if (preg_match("/$regex/", $host)) {
return $provider; // we trust this source, return provider name return false;
} }
} }
throw new ServerException(sprintf(_('Domain not in remote source whitelist: %s'), $host)); return true;
}
/***
* @return boolean true if given url passes whitelist check
*/
protected function checkWhiteList($url)
{
if (!$this->check_whitelist) {
return true;
}
$host = parse_url($url, PHP_URL_HOST);
foreach ($this->domain_whitelist as $regex => $provider) {
if (preg_match("/$regex/", $host)) {
return true;
}
}
return false;
} }
public function onPluginVersion(array &$versions) public function onPluginVersion(array &$versions)