private function encrypt($text, $corpId)
    {
        try {
            $key = $this->getAESKey();
            $random = $this->getRandomStr();
            $text = $this->encode($random.pack('N', strlen($text)).$text.$corpId);

            $iv = substr($key, 0, 16);

            $encrypted = openssl_encrypt($text, 'aes-256-cbc', $key, OPENSSL_RAW_DATA | OPENSSL_NO_PADDING, $iv);

            return base64_encode($encrypted);
        } catch (BaseException $e) {
            throw new EncryptionException($e->getMessage(), EncryptionException::ERROR_ENCRYPT_AES);
        }
    }