}

	return &rsa.PublicKey{
		E: pub.E,
		N: pub.N,
	}, nil
}

// MarshalPKCS1PublicKey converts an [RSA] public key to PKCS #1, ASN.1 DER form.
//
// This kind of key is commonly encoded in PEM blocks of type "RSA PUBLIC KEY".
func MarshalPKCS1PublicKey(key *rsa.PublicKey) []byte {
	derBytes, _ := asn1.Marshal(pkcs1PublicKey{
		N: key.N,
		E: key.E,
	})
	return derBytes

	}
	err = pem.Encode(privatePem, privateKeyBlock)
	if err != nil {
		fmt.Printf("error when encode private pem: %s n", err)
		os.Exit(1)
	}

	// dump public key to file
	publicKeyBytes := x509.MarshalPKCS1PublicKey(&privatekey.PublicKey)
	if err != nil {
		fmt.Printf("error when dumping publickey: %s n", err)
		os.Exit(1)
	}
	publicKeyBlock := &pem.Block{
		Type:  "PUBLIC KEY",
		Bytes: publicKeyBytes,
	}