{
    "mchOrderNo": "test-payout-000024",
    "notifyUrl": "https://webhook.site/8f874726-a8c3-458b-8525-0abb921f243a",
    "amount": 1000,
    "accountName": "jack",
    "accountNo": "0987654321",
    "accountType": 1,
    "phone": "+551234567890",
    "email": "FrancesStanley@Gabspot.com",
    "remark": "ullam qui laborum iste vitae."
}

import (
    "crypto"
    "crypto/rand"
    "crypto/rsa"
    "crypto/sha256"
    "crypto/x509"
    "encoding/pem"
    "encoding/base64"
    "errors"
)

const (
	PrivateKeyTypeStringPKCS8 = "PRIVATE KEY"
	PublicKeyTypeStringPKCS8  = "PUBLIC KEY"
)
func RSASignaturePKCS8(msg []byte, priKey []byte) ([]byte, error) {
	block, _ := pem.Decode(priKey)
	if block == nil || block.Type != PrivateKeyTypeStringPKCS8 {
		log.Println("failed to decode PEM block containing private key")
		return nil, errors.New("failed to decode PEM block containing private key")
	}
	key, err := x509.ParsePKCS8PrivateKey(block.Bytes)
	if err != nil {
		return nil, err
	}
	privateKey := key.(*rsa.PrivateKey)
	hashed := sha256.Sum256(msg)
	data, err := rsa.SignPKCS1v15(rand.Reader, privateKey, crypto.SHA256, hashed[:])
	if err != nil {
		return nil, err
	}
	return data, nil
}

func RSAVerifyPKCS8(msg []byte, signature []byte, pubKey []byte) error {
	block, _ := pem.Decode(pubKey)
	if block == nil || block.Type != PublicKeyTypeStringPKCS8 {
		log.Println("failed to decode PEM block containing public key")
		return errors.New("failed to decode PEM block containing public key")
	}
	key, err := x509.ParsePKIXPublicKey(block.Bytes)
	if err != nil {
		return err
	}
	publicKey := key.(*rsa.PublicKey)
	hashed := sha256.Sum256(msg)
	return rsa.VerifyPKCS1v15(publicKey, crypto.SHA256, hashed[:], signature)
}

func Base64Encode(src []byte) string {
        return base64.StdEncoding.EncodeToString(src)
}