ParagonIE\EasyRSA\EasyRSA::rsaDecrypt PHP Method

    protected static function rsaDecrypt($ciphertext, PrivateKey $rsaPrivateKey)
    {
        static $rsa = null;
        if (!$rsa) {
            $rsa = new RSA();
            $rsa->setEncryptionMode(RSA::ENCRYPTION_OAEP);
            $rsa->setMGFHash('sha256');
        }
        $rsa->loadKey($rsaPrivateKey->getKey());
        $return = @$rsa->decrypt($ciphertext);
        if ($return === false) {
            throw new InvalidCiphertextException('Decryption failed');
        }
        return $return;
    }