package socialwork_sdk

import (
	"crypto"
	"crypto/md5"
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"encoding/base64"
	"encoding/pem"
)

func rsaSignWithMd5Hex(data string, prvKey string) (string, error) {
	block, _ := pem.Decode([]byte(prvKey))
	privateKey, err := x509.ParsePKCS8PrivateKey(block.Bytes)
	if err != nil {
		privateKey, err = x509.ParsePKCS1PrivateKey(block.Bytes)
		if err != nil {
			return "", err
		}
	}
	md5 := md5.New()
	md5.Write([]byte(data))
	hash := md5.Sum(nil)
	signature, err := rsa.SignPKCS1v15(rand.Reader, privateKey.(*rsa.PrivateKey), crypto.MD5, hash[:])
	if err != nil {
		return "", err
	}
	out := base64.StdEncoding.EncodeToString(signature)
	return out, nil
}

func rsaVerifySignWithMd5Base64(originalData, signData, pubKey string) error {
	sign, err := base64.StdEncoding.DecodeString(signData)
	if err != nil {
		return err
	}
	block, _ := pem.Decode([]byte(pubKey))
	pub, err := x509.ParsePKIXPublicKey(block.Bytes)
	if err != nil {
		return err
	}
	hash := md5.New()
	hash.Write([]byte(originalData))
	err = rsa.VerifyPKCS1v15(pub.(*rsa.PublicKey), crypto.MD5, hash.Sum(nil), sign)
	if err != nil {
		return err
	}
	return nil
}