function verify($message, $signature)
    {
        if (empty($this->modulus) || empty($this->exponent)) {
            return false;
        }

        switch ($this->signatureMode) {
            case self::SIGNATURE_PKCS1:
                return $this->_rsassa_pkcs1_v1_5_verify($message, $signature);
            //case self::SIGNATURE_PSS:
            default:
                return $this->_rsassa_pss_verify($message, $signature);
        }
    }