public function verifyHash($input)
    {
        $salt = substr($input, 0, strrpos($input, '$') + 1);
        $checksum = substr($input, strrpos($input, '$') + 1);

        return ($this->verifySalt($salt) && 1 === preg_match('/^[\.\/0-9A-Za-z]{28}$/', $checksum));
    }