server/apps/files_encryption/lib/proxy.php
2012-11-02 19:53:02 +01:00

130 lines
3.8 KiB
PHP

<?php
/**
* ownCloud
*
* @author Robin Appelman
* @copyright 2011 Robin Appelman icewind1991@gmail.com
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
* License as published by the Free Software Foundation; either
* version 3 of the License, or any later version.
*
* This library 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 this library. If not, see <http://www.gnu.org/licenses/>.
*
*/
/**
* transparent encryption
*/
class OC_FileProxy_Encryption extends OC_FileProxy{
private static $blackList=null; //mimetypes blacklisted from encryption
private static $enableEncryption=null;
/**
* check if a file should be encrypted during write
* @param string $path
* @return bool
*/
private static function shouldEncrypt($path) {
if(is_null(self::$enableEncryption)) {
self::$enableEncryption=(OCP\Config::getAppValue('files_encryption','enable_encryption','true')=='true');
}
if(!self::$enableEncryption) {
return false;
}
if(is_null(self::$blackList)) {
self::$blackList=explode(',', OCP\Config::getAppValue('files_encryption', 'type_blacklist', 'jpg,png,jpeg,avi,mpg,mpeg,mkv,mp3,oga,ogv,ogg'));
}
if(self::isEncrypted($path)) {
return true;
}
$extension=substr($path, strrpos($path, '.')+1);
if(array_search($extension, self::$blackList)===false) {
return true;
}
}
/**
* check if a file is encrypted
* @param string $path
* @return bool
*/
private static function isEncrypted($path) {
$metadata=OC_FileCache_Cached::get($path,'');
return isset($metadata['encrypted']) and (bool)$metadata['encrypted'];
}
public function preFile_put_contents($path,&$data) {
if(self::shouldEncrypt($path)) {
if (!is_resource($data)) {//stream put contents should have been converter to fopen
$size=strlen($data);
$data=OC_Crypt::blockEncrypt($data);
OC_FileCache::put($path, array('encrypted'=>true,'size'=>$size),'');
}
}
}
public function postFile_get_contents($path,$data) {
if(self::isEncrypted($path)) {
$cached=OC_FileCache_Cached::get($path,'');
$data=OC_Crypt::blockDecrypt($data, '', $cached['size']);
}
return $data;
}
public function postFopen($path,&$result) {
if(!$result) {
return $result;
}
$meta=stream_get_meta_data($result);
if(self::isEncrypted($path)) {
fclose($result);
$result=fopen('crypt://'.$path, $meta['mode']);
}elseif(self::shouldEncrypt($path) and $meta['mode']!='r' and $meta['mode']!='rb') {
if(OC_Filesystem::file_exists($path) and OC_Filesystem::filesize($path)>0) {
//first encrypt the target file so we don't end up with a half encrypted file
OCP\Util::writeLog('files_encryption','Decrypting '.$path.' before writing',OCP\Util::DEBUG);
$tmp=fopen('php://temp');
OCP\Files::streamCopy($result, $tmp);
fclose($result);
OC_Filesystem::file_put_contents($path, $tmp);
fclose($tmp);
}
$result=fopen('crypt://'.$path, $meta['mode']);
}
return $result;
}
public function postGetMimeType($path, $mime) {
if(self::isEncrypted($path)) {
$mime=OCP\Files::getMimeType('crypt://'.$path,'w');
}
return $mime;
}
public function postStat($path, $data) {
if(self::isEncrypted($path)) {
$cached=OC_FileCache_Cached::get($path,'');
$data['size']=$cached['size'];
}
return $data;
}
public function postFileSize($path, $size) {
if(self::isEncrypted($path)) {
$cached=OC_FileCache_Cached::get($path,'');
return $cached['size'];
}else{
return $size;
}
}
}