protected function _getSettings($input)
    {
        $parts = array ();
        $matches = array ();
        if (1 === preg_match('/^\$sha1\$(\d+)\$([\.\/0-9A-Za-z]{0,64})(?:\$([\.\/0-9A-Za-z]{28}))?$/', rtrim($input, '$'), $matches)) {
            $parts['rounds'] = $matches[1];
            $parts['salt'] = $matches[2];
            $parts['checksum'] = $matches[3] ?: null;
        }

        return $parts;
    }