}
	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,
	}