encryption proxy wip

1 files changed, 121 insertions, 0 deletions

diff --git a/apps/files_encryption/lib/cryptstream.php b/apps/files_encryption/lib/cryptstream.php
new file mode 100644
index 00000000000..e4544313f63
--- /dev/null
+++ b/apps/files_encryption/lib/cryptstream.php
@@ -0,0 +1,121 @@
+<?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
+ */
+
+class OC_CryptStream{
+	private $source;
+
+	public function stream_open($path, $mode, $options, &$opened_path){
+		$path=str_replace('crypt://','',$path);
+		$this->source=OC_FileSystem::fopen($path.'.enc',$mode);
+		if(!is_resource($this->source)){
+			OC_Log::write('files_encryption','failed to open '.$path.'.enc',OC_Log::ERROR);
+		}
+		return is_resource($this->source);
+	}
+	
+	public function stream_seek($offset, $whence=SEEK_SET){
+		fseek($this->source,$offset,$whence);
+	}
+	
+	public function stream_tell(){
+		return ftell($this->source);
+	}
+	
+	public function stream_read($count){
+		$pos=0;
+		$currentPos=ftell($this->source);
+		$offset=$currentPos%8192;
+		fseek($this->source,-$offset,SEEK_CUR);
+		$result='';
+		while($count>$pos){
+			$data=fread($this->source,8192);
+			$pos+=8192;
+			$result.=OC_Crypt::decrypt($data);
+		}
+		return substr($result,$offset,$count);
+	}
+	
+	public function stream_write($data){
+		$length=strlen($data);
+		$written=0;
+		$currentPos=ftell($this->source);
+		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;
+		}
+		while(strlen($data)>0){
+			if(strlen($data)<8192){
+				//fetch the current data in that block and append it to the input so we always write entire blocks
+				$oldPos=ftell($this->source);
+				$encryptedBlock=fread($this->source,8192);
+				fseek($this->source,$oldPos);
+				$block=OC_Crypt::decrypt($encryptedBlock);
+				$data.=substr($block,strlen($data));
+			}
+			$encrypted=OC_Crypt::encrypt(substr($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($this->source);
+	}
+
+	public function stream_close(){
+		return fclose($this->source);
+	}
+}
\ No newline at end of file