diff options
Diffstat (limited to 'p/ext.php')
| -rw-r--r-- | p/ext.php | 34 |
1 files changed, 33 insertions, 1 deletions
@@ -7,10 +7,42 @@ if (!isset($_GET['f']) || require('../constants.php'); +/** + * Check if a file can be served by ext.php. A valid file is under a + * EXTENSIONS_PATH/extension_name/static/ directory. + * + * You should sanitize path by using the realpath() function. + * + * @param $path the path to the file we want to serve. + * @return true if it can be served, false else. + * + */ +function is_valid_path($path) { + // It must be under the extension path. + $in_ext_path = (substr($path, 0, strlen(EXTENSIONS_PATH)) === EXTENSIONS_PATH); + if (!$in_ext_path) { + return false; + } + + // File to serve must be under a `ext_dir/static/` directory. + $path_relative_to_ext = substr($path, strlen(EXTENSIONS_PATH) + 1); + $path_splitted = explode('/', $path_relative_to_ext); + if (count($path_splitted) < 3 || $path_splitted[1] !== 'static') { + return false; + } + + return true; +} + $file_name = urldecode($_GET['f']); $file_type = $_GET['t']; -$absolute_filename = EXTENSIONS_PATH . '/' . $file_name; +$absolute_filename = realpath(EXTENSIONS_PATH . '/' . $file_name); + +if (!is_valid_path($absolute_filename)) { + header('HTTP/1.1 400 Bad Request'); + die(); +} switch ($file_type) { case 'css': |