175 lines
5.0 KiB
PHP
175 lines
5.0 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/>.
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* 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 $meta=array();//header/meta for source stream
|
|
private $writeCache;
|
|
private $size;
|
|
private static $rootView;
|
|
|
|
public function stream_open($path, $mode, $options, &$opened_path) {
|
|
if(!self::$rootView) {
|
|
self::$rootView=new \OC\Files\View('');
|
|
}
|
|
$path=str_replace('crypt://','',$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'];
|
|
$this->size=self::$sourceStreams[basename($path)]['size'];
|
|
}else{
|
|
$this->path=$path;
|
|
if($mode=='w' or $mode=='w+' or $mode=='wb' or $mode=='wb+') {
|
|
$this->size=0;
|
|
}else{
|
|
$this->size=self::$rootView->filesize($path,$mode);
|
|
}
|
|
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();
|
|
}
|
|
$pos=ftell($this->source);
|
|
$data=fread($this->source,8192);
|
|
if(strlen($data)) {
|
|
$result=OC_Crypt::decrypt($data);
|
|
}else{
|
|
$result='';
|
|
}
|
|
$length=$this->size-$pos;
|
|
if($length<8192) {
|
|
$result=substr($result,0,$length);
|
|
}
|
|
return $result;
|
|
}
|
|
|
|
public function stream_write($data) {
|
|
$length=strlen($data);
|
|
$currentPos=ftell($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);
|
|
}
|
|
$currentPos=ftell($this->source);
|
|
while($remainingLength=strlen($data)>0) {
|
|
if($remainingLength<8192) {
|
|
$this->writeCache=$data;
|
|
$data='';
|
|
}else{
|
|
$encrypted=OC_Crypt::encrypt(substr($data,0,8192));
|
|
fwrite($this->source,$encrypted);
|
|
$data=substr($data,8192);
|
|
}
|
|
}
|
|
$this->size=max($this->size,$currentPos+$length);
|
|
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,'size'=>$this->size),'');
|
|
}
|
|
return fclose($this->source);
|
|
}
|
|
}
|