/**
 * @Author: zhangsan
 * @Description:
 * @File:  rsaTool
 * @Version: 1.0.0
 * @Date: 2021/1/19 下午1:51
 */

package rsa

import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/sha256"
	"crypto/x509"
	"encoding/pem"
	"errors"
)
///
// encryption
///
func Encryption(str []byte,pubKey *rsa.PublicKey)(msg []byte,err error){
	msg, err = rsa.EncryptOAEP(
		sha256.New(),
		rand.Reader,
		pubKey,
		str,
		nil)
	return
}

///
// decryption
///
func Decryption(enStr []byte,priKey *rsa.PrivateKey)(msg []byte,err error){
	msg, err = rsa.DecryptOAEP(
		sha256.New(),
		rand.Reader,
		priKey,
		enStr,
		nil)
	return
}



///
// string to rsa.PublicKey
///
func getPubKey(str []byte)(*rsa.PublicKey, error){
	block, _ := pem.Decode(str)
	if block == nil {
		return nil, errors.New("get public key error")
	}
	// x509 parse public key
	pub, err := x509.ParsePKIXPublicKey(block.Bytes)
	if err != nil {
		return nil, err
	}
	return pub.(*rsa.PublicKey), err
}
///
// string to rsa.PrivateKey
///
func getPriKey(str string)(*rsa.PrivateKey, error){
	block, _ := pem.Decode([]byte(str))
	if block == nil {
		return nil, errors.New("get private key error")
	}
	pri, err := x509.ParsePKCS1PrivateKey(block.Bytes)
	if err == nil {
		return pri, nil
	}
	pri2, err := x509.ParsePKCS8PrivateKey(block.Bytes)
	if err != nil {
		return nil, err
	}
	return  pri2.(*rsa.PrivateKey),err
}

借鉴

借鉴 “github.com/wenzhenxi/gorsa”
https://blog.csdn.net/u011142688/article/details/79380129