nextcloud/apps/files_encryption/lib/proxy.php

129 lines
3.5 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 $metaData=array(); //metadata cache
/**
* check if a file should be encrypted during write
* @param string $path
* @return bool
*/
private static function shouldEncrypt($path){
if(is_null(self::$blackList)){
self::$blackList=explode(',',OC_Appconfig::getValue('files_encryption','type_blacklist','jpg,png,jpeg,avi,mpg,mpeg,mkv,mp3,oga,ogv,ogg'));
}
if(isset(self::$metaData[$path])){
$metadata=self::$metaData[$path];
}else{
$metadata=OC_FileCache::get($path);
self::$metaData[$path]=$metadata;
}
if($metadata['encrypted']){
return true;
}
$extention=substr($path,strrpos($path,'.')+1);
if(array_search($extention,self::$blackList)===false){
return true;
}
}
/**
* check if a file is encrypted
* @param string $path
* @return bool
*/
private static function isEncrypted($path){
if(isset(self::$metaData[$path])){
$metadata=self::$metaData[$path];
}else{
$metadata=OC_FileCache::get($path);
self::$metaData[$path]=$metadata;
}
return (bool)$metadata['encrypted'];
}
public function preFile_put_contents($path,&$data){
if(self::shouldEncrypt($path)){
$exists=OC_Filesystem::file_exists($path);
$target=fopen('crypt://'.$path,'w');
if (is_resource($data)) {
while(!feof($data)){
fwrite($target,fread($data,8192));
}
}else{
fwrite($target,$data);
}
//fake the normal hooks
OC_Hook::emit( 'OC_Filesystem', 'post_create', array( 'path' => $path));
OC_Hook::emit( 'OC_Filesystem', 'post_write', array( 'path' => $path));
return false;
}
}
public function postFile_get_contents($path,$data){
if(self::isEncrypted($path)){
$data=OC_Crypt::blockDecrypt($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 $meta['mode']!='r'){
if(OC_Filesystem::file_exists($path)){
//first encrypt the target file so we don't end up with a half encrypted file
OC_Log::write('files_encryption','Decrypting '.$path.' before writing',OC_Log::DEBUG);
if($result){
fclose($result);
}
$tmpFile=OC_Filesystem::toTmpFile($path);
OC_Filesystem::fromTmpFile($tmpFile,$path);
}
$result=fopen('crypt://'.$path,$meta['mode']);
}
return $result;
}
public function preReadFile($path){
if(self::isEncrypted($path)){
$stream=fopen('crypt://'.$path,'r');
while(!feof($stream)){
print(fread($stream,8192));
}
return false;//cancel the original request
}
}
}