Create and verify file download keys without adding too much data to the session

This commit is contained in:
Kijin Sung 2015-07-14 21:20:49 +09:00
parent 0dc114b5b2
commit dda0ad41f7

View file

@ -263,25 +263,30 @@ class fileController extends file
}
}
}
// Call a trigger (before)
$output = ModuleHandler::triggerCall('file.downloadFile', 'before', $file_obj);
if(!$output->toBool()) return $this->stop(($output->message)?$output->message:'msg_not_permitted_download');
// 다운로드 후 (가상)
// Increase download_count
$args = new stdClass();
$args->file_srl = $file_srl;
executeQuery('file.updateFileDownloadCount', $args);
// Call a trigger (after)
$output = ModuleHandler::triggerCall('file.downloadFile', 'after', $file_obj);
$random = new Password();
$file_key = $_SESSION['__XE_FILE_KEY__'][$file_srl] = $random->createSecureSalt(32, 'hex');
// Redirect to procFileOutput using file key
if(!isset($_SESSION['__XE_FILE_KEY__']) || !is_string($_SESSION['__XE_FILE_KEY__']) || strlen($_SESSION['__XE_FILE_KEY__']) != 32)
{
$random = new Password();
$_SESSION['__XE_FILE_KEY__'] = $random->createSecureSalt(32, 'hex');
}
$file_key_data = $file_obj->file_srl . $file_obj->file_size . $file_obj->uploaded_filename . $_SERVER['REMOTE_ADDR'] . $_SERVER['HTTP_USER_AGENT'];
$file_key = substr(hash_hmac('sha256', $file_key_data, $_SESSION['__XE_FILE_KEY__']), 0, 32);
header('Location: '.getNotEncodedUrl('', 'act', 'procFileOutput','file_srl',$file_srl,'file_key',$file_key));
Context::close();
exit();
}
public function procFileOutput()
@ -297,6 +302,18 @@ class fileController extends file
$filename = $file_obj->source_filename;
$etag = md5($file_srl . $file_key . $_SERVER['HTTP_USER_AGENT']);
// Check file key
if(strlen($file_key) != 32 || !isset($_SESSION['__XE_FILE_KEY__']) || !is_string($_SESSION['__XE_FILE_KEY__']))
{
return $this->stop('msg_invalid_request');
}
$file_key_data = $file_srl . $file_obj->file_size . $file_obj->uploaded_filename . $_SERVER['REMOTE_ADDR'] . $_SERVER['HTTP_USER_AGENT'];
$file_key_compare = substr(hash_hmac('sha256', $file_key_data, $_SESSION['__XE_FILE_KEY__']), 0, 32);
if($file_key !== $file_key_compare)
{
return $this->stop('msg_invalid_request');
}
// Check if file exists
$uploaded_filename = $file_obj->uploaded_filename;
if(!file_exists($uploaded_filename))
@ -318,34 +335,6 @@ class fileController extends file
exit();
}
// Android <= 4.0 tries to download the same file twice, so we allow it
if(strstr($_SERVER['HTTP_USER_AGENT'], "Android"))
{
$is_android = true;
}
if($is_android && $_SESSION['__XE_FILE_KEY_AND__'][$file_srl])
{
$session_key = '__XE_FILE_KEY_AND__';
}
else
{
$session_key = '__XE_FILE_KEY__';
}
// If not Android, we do not allow downloading the same file twice
if(!$file_key || $_SESSION[$session_key][$file_srl] != $file_key)
{
unset($_SESSION[$session_key][$file_srl]);
return $this->stop('msg_invalid_request');
}
if($is_android)
{
if($_SESSION['__XE_FILE_KEY__'][$file_srl]) $_SESSION['__XE_FILE_KEY_AND__'][$file_srl] = $file_key;
}
unset($_SESSION[$session_key][$file_srl]);
// Filename encoding for browsers that support RFC 5987
if(preg_match('#(?:Chrome|Edge)/(\d+)\.#', $_SERVER['HTTP_USER_AGENT'], $matches) && $matches[1] >= 11)
{