package unionpay

import (
	"crypto"
	"crypto/rand"
	"crypto/rsa"
	"crypto/sha1"
	"crypto/sha256"
)

// encrypt RSA 加密
func encrypt(publicKey *rsa.PublicKey, src []byte) (data []byte, err error) {
	data, err = rsa.EncryptPKCS1v15(rand.Reader, publicKey, src)
	return
}

// decrypt RSA 解密
func decrypt(priveKey *rsa.PrivateKey, ciphertext []byte) (data []byte, err error) {
	data, err = rsa.DecryptPKCS1v15(rand.Reader, priveKey, ciphertext)

	return
}

// sign RSA 签名
func sign(priveKey *rsa.PrivateKey, src []byte) (data []byte, err error) {
	hashed := sha256.Sum256(src)
	//hashed = sha256.Sum256(hashed[:])
	data, err = rsa.SignPKCS1v15(rand.Reader, priveKey, crypto.SHA256, hashed[:])
	return
}

// signsha1 RSA sha1签名
func signsha1(priveKey *rsa.PrivateKey, src []byte) (data []byte, err error) {
	hashed := sha1.Sum(src)
	data, err = rsa.SignPKCS1v15(rand.Reader, priveKey, crypto.SHA1, hashed[:])
	return
}

// verify RSA 签名验证
func verify(publicKey *rsa.PublicKey, src, sig []byte) (err error) {
	hashed := sha256.Sum256(src)
	err = rsa.VerifyPKCS1v15(publicKey, crypto.SHA256, hashed[:], sig)
	return
}