nextcloud/apps/files_encryption/lib/proxy.php

170 lines
4.2 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 requires encryption
* @param string $path
* @return bool
*
* Tests if encryption is enabled, and file is allowed by blacklists
*/
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;
}
return false;
}
/**
* Check if a file is encrypted according to database file cache
* @param string $path
* @return bool
*/
private static function isEncrypted( $path ){
// Fetch all file metadata from DB
$metadata = OC_FileCache_Cached::get( $path, '' );
// Return encryption status
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 = OCA_Encryption\Crypt::symmetricEncryptFileContent( $data, '', $cached['size'] );
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 = OCA_Encryption\Crypt::symmetricDecryptFileContent( $data, '' );
}
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;
}
}
}