public function stream_open($path, $mode, $options, &$opened_path)
{
$this->loadContext('ocencryption');
$this->position = 0;
$this->cache = '';
$this->writeFlag = false;
$this->unencryptedBlockSize = $this->encryptionModule->getUnencryptedBlockSize($this->signed);
if ($mode === 'w' || $mode === 'w+' || $mode === 'wb' || $mode === 'wb+' || $mode === 'r+' || $mode === 'rb+') {
$this->readOnly = false;
} else {
$this->readOnly = true;
}
$sharePath = $this->fullPath;
if (!$this->storage->file_exists($this->internalPath)) {
$sharePath = dirname($sharePath);
}
$accessList = $this->file->getAccessList($sharePath);
$this->newHeader = $this->encryptionModule->begin($this->fullPath, $this->uid, $mode, $this->header, $accessList);
if ($mode === 'w' || $mode === 'w+' || $mode === 'wb' || $mode === 'wb+') {
// We're writing a new file so start write counter with 0 bytes
$this->unencryptedSize = 0;
$this->writeHeader();
$this->headerSize = $this->util->getHeaderSize();
$this->size = $this->headerSize;
} else {
$this->skipHeader();
}
return true;
}
public function stream_seek($offset, $whence = SEEK_SET)
{
$return = false;
switch ($whence) {
case SEEK_SET:
if ($offset < $this->unencryptedSize && $offset >= 0) {
$newPosition = $offset;
}
break;
case SEEK_CUR:
if ($offset >= 0) {
$newPosition = $offset + $this->position;
}
break;
case SEEK_END:
if ($this->unencryptedSize + $offset >= 0) {
$newPosition = $this->unencryptedSize + $offset;
}
break;
default:
return $return;
}
$newFilePosition = floor($newPosition / $this->unencryptedBlockSize) * $this->util->getBlockSize() + $this->util->getHeaderSize();
$oldFilePosition = parent::stream_tell();
if (parent::stream_seek($newFilePosition)) {
parent::stream_seek($oldFilePosition);
$this->flush();
parent::stream_seek($newFilePosition);
$this->position = $newPosition;
$return = true;
}
return $return;
}
/**
* read first block of encrypted file, typically this will contain the
* encryption header
*
* @param string $path
* @return string
*/
protected function readFirstBlock($path) {
$firstBlock = '';
if ($this->storage->file_exists($path)) {
$handle = $this->storage->fopen($path, 'r');
$firstBlock = fread($handle, $this->util->getHeaderSize());
fclose($handle);
}
return $firstBlock;
}
/**
* read header from file
*
* @param string $path
* @return array
*/
protected function getHeader($path)
{
$header = '';
if ($this->storage->file_exists($path)) {
$handle = $this->storage->fopen($path, 'r');
$header = fread($handle, $this->util->getHeaderSize());
fclose($handle);
}
return $this->util->readHeader($header);
}
/**
* read header from file
*
* @param string $path
* @return array
*/
protected function getHeader($path)
{
$header = '';
if ($this->storage->file_exists($path)) {
$handle = $this->storage->fopen($path, 'r');
$firstBlock = fread($handle, $this->util->getHeaderSize());
fclose($handle);
if (substr($firstBlock, 0, strlen(Util::HEADER_START)) === Util::HEADER_START) {
$header = $firstBlock;
}
}
return $header;
}
/**
* return header size of given file
*
* @param string $path
* @return int
*/
protected function getHeaderSize($path)
{
$headerSize = 0;
$realFile = $this->util->stripPartialFileExtension($path);
if ($this->storage->file_exists($realFile)) {
$path = $realFile;
}
$firstBlock = $this->readFirstBlock($path);
if (substr($firstBlock, 0, strlen(Util::HEADER_START)) === Util::HEADER_START) {
$headerSize = $this->util->getHeaderSize();
}
return $headerSize;
}
