/**
* get the file size of the unencrypted file
* @param string $path absolute path
* @return bool
*/
public function getFileSize($path)
{
$result = 0;
// Disable encryption proxy to prevent recursive calls
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
// split the path parts
$pathParts = explode('/', $path);
if (isset($pathParts[2]) && $pathParts[2] === 'files' && $this->view->file_exists($path) && $this->isEncryptedPath($path)) {
$cipher = 'AES-128-CFB';
$realSize = 0;
// get the size from filesystem
$size = $this->view->filesize($path);
// open stream
$stream = $this->view->fopen($path, "r");
if (is_resource($stream)) {
// if the file contains a encryption header we
// we set the cipher
// and we update the size
if ($this->containHeader($path)) {
$data = fread($stream, Crypt::BLOCKSIZE);
$header = Crypt::parseHeader($data);
$cipher = Crypt::getCipher($header);
$size -= Crypt::BLOCKSIZE;
}
// fast path, else the calculation for $lastChunkNr is bogus
if ($size === 0) {
\OC_FileProxy::$enabled = $proxyStatus;
return 0;
}
// calculate last chunk nr
// next highest is end of chunks, one subtracted is last one
// we have to read the last chunk, we can't just calculate it (because of padding etc)
$lastChunkNr = ceil($size / Crypt::BLOCKSIZE) - 1;
// calculate last chunk position
$lastChunkPos = $lastChunkNr * Crypt::BLOCKSIZE;
// get the content of the last chunk
if (@fseek($stream, $lastChunkPos, SEEK_CUR) === 0) {
$realSize += $lastChunkNr * 6126;
}
$lastChunkContentEncrypted = '';
$count = Crypt::BLOCKSIZE;
while ($count > 0) {
$data = fread($stream, Crypt::BLOCKSIZE);
$count = strlen($data);
$lastChunkContentEncrypted .= $data;
if (strlen($lastChunkContentEncrypted) > Crypt::BLOCKSIZE) {
$realSize += 6126;
$lastChunkContentEncrypted = substr($lastChunkContentEncrypted, Crypt::BLOCKSIZE);
}
}
fclose($stream);
$relPath = Helper::stripUserFilesPath($path);
$shareKey = Keymanager::getShareKey($this->view, $this->keyId, $this, $relPath);
if ($shareKey === false) {
\OC_FileProxy::$enabled = $proxyStatus;
return $result;
}
$session = new Session($this->view);
$privateKey = $session->getPrivateKey();
$plainKeyfile = $this->decryptKeyfile($relPath, $privateKey);
$plainKey = Crypt::multiKeyDecrypt($plainKeyfile, $shareKey, $privateKey);
$lastChunkContent = Crypt::symmetricDecryptFileContent($lastChunkContentEncrypted, $plainKey, $cipher);
// calc the real file size with the size of the last chunk
$realSize += strlen($lastChunkContent);
// store file size
$result = $realSize;
}
}
\OC_FileProxy::$enabled = $proxyStatus;
return $result;
}
private function readHeader()
{
if ($this->isLocalTmpFile) {
$handle = fopen($this->localTmpFile, 'r');
} else {
$handle = $this->rootView->fopen($this->rawPath, 'r');
}
if (is_resource($handle)) {
$data = fread($handle, Crypt::BLOCKSIZE);
$header = Crypt::parseHeader($data);
$this->cipher = Crypt::getCipher($header);
// remeber that we found a header
if (!empty($header)) {
$this->containHeader = true;
}
fclose($handle);
}
}
