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- <?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/>.
- *
- */
- /**
- * transparently encrypted filestream
- *
- * you can use it as wrapper around an existing stream by setting OC_CryptStream::$sourceStreams['foo']=array('path'=>$path,'stream'=>$stream)
- * and then fopen('crypt://streams/foo');
- */
- class OC_CryptStream{
- public static $sourceStreams=array();
- private $source;
- private $path;
- private $readBuffer;//for streams that dont support seeking
- private $meta=array();//header/meta for source stream
- private $count;
- private $writeCache;
- private static $rootView;
- public function stream_open($path, $mode, $options, &$opened_path){
- if(!self::$rootView){
- self::$rootView=new OC_FilesystemView('');
- }
- $path=str_replace('crypt://','',$path);
- if(dirname($path)=='streams' and isset(self::$sourceStreams[basename($path)])){
- $this->source=self::$sourceStreams[basename($path)]['stream'];
- $this->path=self::$sourceStreams[basename($path)]['path'];
- }else{
- $this->path=$path;
- OC_FileProxy::$enabled=false;//disable fileproxies so we can open the source file
- $this->source=self::$rootView->fopen($path,$mode);
- OC_FileProxy::$enabled=true;
- if(!is_resource($this->source)){
- OCP\Util::writeLog('files_encryption','failed to open '.$path,OCP\Util::ERROR);
- }
- }
- if(is_resource($this->source)){
- $this->meta=stream_get_meta_data($this->source);
- }
- return is_resource($this->source);
- }
-
- public function stream_seek($offset, $whence=SEEK_SET){
- $this->flush();
- fseek($this->source,$offset,$whence);
- }
-
- public function stream_tell(){
- return ftell($this->source);
- }
-
- public function stream_read($count){
- //$count will always be 8192 https://bugs.php.net/bug.php?id=21641
- //This makes this function a lot simpler but will breake everything the moment it's fixed
- $this->writeCache='';
- if($count!=8192){
- OCP\Util::writeLog('files_encryption','php bug 21641 no longer holds, decryption will not work',OCP\Util::FATAL);
- die();
- }
- $data=fread($this->source,8192);
- if(strlen($data)){
- $result=OC_Crypt::decrypt($data);
- }else{
- $result='';
- }
- if($this->stream_eof()){
- $result=rtrim($result, "\0");
- }
- return $result;
- }
-
- public function stream_write($data){
- $length=strlen($data);
- $written=0;
- $currentPos=ftell($this->source);
- if($this->writeCache){
- $data=$this->writeCache.$data;
- $this->writeCache='';
- }
- if($currentPos%8192!=0){
- //make sure we always start on a block start
- fseek($this->source,-($currentPos%8192),SEEK_CUR);
- $encryptedBlock=fread($this->source,8192);
- fseek($this->source,-($currentPos%8192),SEEK_CUR);
- $block=OC_Crypt::decrypt($encryptedBlock);
- $data=substr($block,0,$currentPos%8192).$data;
- fseek($this->source,-($currentPos%8192),SEEK_CUR);
- }
- while(strlen($data)>0){
- if(strlen($data)<8192){
- $this->writeCache=$data;
- $data='';
- }else{
- $encrypted=OC_Crypt::encrypt(substr($data,0,8192));
- fwrite($this->source,$encrypted);
- $data=substr($data,8192);
- }
- }
- return $length;
- }
- public function stream_set_option($option,$arg1,$arg2){
- switch($option){
- case STREAM_OPTION_BLOCKING:
- stream_set_blocking($this->source,$arg1);
- break;
- case STREAM_OPTION_READ_TIMEOUT:
- stream_set_timeout($this->source,$arg1,$arg2);
- break;
- case STREAM_OPTION_WRITE_BUFFER:
- stream_set_write_buffer($this->source,$arg1,$arg2);
- }
- }
- public function stream_stat(){
- return fstat($this->source);
- }
-
- public function stream_lock($mode){
- flock($this->source,$mode);
- }
-
- public function stream_flush(){
- return fflush($this->source);
- }
- public function stream_eof(){
- return feof($this->source);
- }
- private function flush(){
- if($this->writeCache){
- $encrypted=OC_Crypt::encrypt($this->writeCache);
- fwrite($this->source,$encrypted);
- $this->writeCache='';
- }
- }
- public function stream_close(){
- $this->flush();
- if($this->meta['mode']!='r' and $this->meta['mode']!='rb'){
- OC_FileCache::put($this->path,array('encrypted'=>true));
- }
- return fclose($this->source);
- }
- }
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