Go语言 如何实现RSA加密解密

import (
	"crypto/rsa"
	"crypto/rand"
	"crypto/x509"
	"os"
	"encoding/pem"
	"fmt"
)
//生成RSA私钥和公钥，保存到文件中
func GenerateRSAKey(bits int){
	//GenerateKey函数使用随机数据生成器random生成一对具有指定字位数的RSA密钥
	//Reader是一个全局、共享的密码用强随机数生成器
	privateKey, err := rsa.GenerateKey(rand.Reader, bits)
	if err!=nil{
		panic(err)
	}
	//保存私钥
	//通过x509标准将得到的ras私钥序列化为ASN.1 的 DER编码字符串
	X509PrivateKey := x509.MarshalPKCS1PrivateKey(privateKey)
	//使用pem格式对x509输出的内容进行编码
	//创建文件保存私钥
	privateFile, err := os.Create("private.pem")
	if err!=nil{
		panic(err)
	}
	defer privateFile.Close()
	//构建一个pem.Block结构体对象
	privateBlock:= pem.Block{Type: "RSA Private Key",Bytes:X509PrivateKey}
	//将数据保存到文件
	pem.Encode(privateFile,&privateBlock)
	//保存公钥
	//获取公钥的数据
	publicKey:=privateKey.PublicKey
	//X509对公钥编码
	X509PublicKey,err:=x509.MarshalPKIXPublicKey(&publicKey)
	if err!=nil{
		panic(err)
	}
	//pem格式编码
	//创建用于保存公钥的文件
	publicFile, err := os.Create("public.pem")
	if err!=nil{
		panic(err)
	}
	defer publicFile.Close()
	//创建一个pem.Block结构体对象
	publicBlock:= pem.Block{Type: "RSA Public Key",Bytes:X509PublicKey}
	//保存到文件
	pem.Encode(publicFile,&publicBlock)
}
//RSA加密
func RSA_Encrypt(plainText []byte,path string)[]byte{
	//打开文件
	file,err:=os.Open(path)
	if err!=nil{
		panic(err)
	}
	defer file.Close()
	//读取文件的内容
	info, _ := file.Stat()
	buf:=make([]byte,info.Size())
	file.Read(buf)
	//pem解码
	block, _ := pem.Decode(buf)
	//x509解码
	publicKeyInterface, err := x509.ParsePKIXPublicKey(block.Bytes)
	if err!=nil{
		panic(err)
	}
	//类型断言
	publicKey:=publicKeyInterface.(*rsa.PublicKey)
	//对明文进行加密
	cipherText, err := rsa.EncryptPKCS1v15(rand.Reader, publicKey, plainText)
	if err!=nil{
		panic(err)
	}
	//返回密文
	return cipherText
}
//RSA解密
func RSA_Decrypt(cipherText []byte,path string) []byte{
	//打开文件
	file,err:=os.Open(path)
	if err!=nil{
		panic(err)
	}
	defer file.Close()
	//获取文件内容
	info, _ := file.Stat()
	buf:=make([]byte,info.Size())
	file.Read(buf)
	//pem解码
	block, _ := pem.Decode(buf)
	//X509解码
	privateKey, err := x509.ParsePKCS1PrivateKey(block.Bytes)
	if err!=nil{
		panic(err)
	}
	//对密文进行解密
	plainText,_:=rsa.DecryptPKCS1v15(rand.Reader,privateKey,cipherText)
	//返回明文
	return plainText
}

func main(){
 //生成密钥对，保存到文件
 GenerateRSAKey(2048)
 message:=[]byte("hello world")
 //加密
 cipherText:=RSA_Encrypt(message,"public.pem")
 fmt.Println("加密后为：",string(cipherText))
 //解密
 plainText := RSA_Decrypt(cipherText, "private.pem")
 fmt.Println("解密后为：",string(plainText))
}

hex.DecodeString(s string)//解密
hex.EncodeToString(src []byte) string//加密

base64.StdEncoding.DecodeString(s string) ([]byte, error)//解密
base64.StdEncoding.EncodeToString(src []byte) string//加密

x509.ParsePKCS1PrivateKey(der []byte) (key interface{}, err error)

x509.ParsePKCS8PrivateKey(der []byte) (key interface{}, err error)

    hash := sha1.New()
 hash.Write([]byte(originalData))
 encryptedData, err := rsa.SignPKCS1v15(rand.Reader, prvKey, crypto.SHA1, hash.Sum(nil))

    hash := sha256.New()
 hash.Write([]byte(originalData))
 encryptedData, err := rsa.SignPKCS1v15(rand.Reader, prvKey, crypto.SHA256, hash.Sum(nil))

rsa.EncryptPKCS1v15(rand io.Reader, pub *PublicKey, msg []byte) ([]byte, error)

rsa.DecryptPKCS1v15(rand io.Reader, priv *PrivateKey, ciphertext []byte) ([]byte, error)

rsa.SignPKCS1v15(rand io.Reader, priv *PrivateKey, hash crypto.Hash, hashed []byte) ([]byte, error)

rsa.VerifyPKCS1v15(pub *PublicKey, hash crypto.Hash, hashed []byte, sig []byte) error

（1）加密：采用sha1算法加密后转base64格式
func RsaEncryptWithSha1Base64(originalData,publicKey string)(string,error){
   key, _ := base64.StdEncoding.DecodeString(publicKey)
   pubKey, _ := x509.ParsePKIXPublicKey(key)
   encryptedData,err:=rsa.EncryptPKCS1v15(rand.Reader, pubKey.(*rsa.PublicKey), []byte(originalData))
   return base64.StdEncoding.EncodeToString(encryptedData),err
}
（2）解密：对采用sha1算法加密后转base64格式的数据进行解密（私钥PKCS1格式）
func RsaDecryptWithSha1Base64(encryptedData,privateKey string)(string,error){
   encryptedDecodeBytes,err:=base64.StdEncoding.DecodeString(encryptedData)
   if err!=nil {
      return "",err
   }
   key,_:=base64.StdEncoding.DecodeString(privateKey)
   prvKey,_:=x509.ParsePKCS1PrivateKey(key)
   originalData,err:=rsa.DecryptPKCS1v15(rand.Reader,prvKey,encryptedDecodeBytes)
   return string(originalData),err
}
（3）签名：采用sha1算法进行签名并输出为hex格式（私钥PKCS8格式）
func RsaSignWithSha1Hex(data string, prvKey string) (string, error) {
   keyByts, err := hex.DecodeString(prvKey)
   if err != nil {
      fmt.Println(err)
      return "", err
   }
   privateKey, err := x509.ParsePKCS8PrivateKey(keyByts)
   if err != nil {
      fmt.Println("ParsePKCS8PrivateKey err", err)
      return "", err
   }
   h := sha1.New()
   h.Write([]byte([]byte(data)))
   hash := h.Sum(nil)
   signature, err := rsa.SignPKCS1v15(rand.Reader, privateKey.(*rsa.PrivateKey), crypto.SHA1, hash[:])
   if err != nil {
      fmt.Printf("Error from signing: %s\n", err)
      return "", err
   }
   out := hex.EncodeToString(signature)
   return out, nil
}
（4）验签：对采用sha1算法进行签名后转base64格式的数据进行验签
func RsaVerySignWithSha1Base64(originalData, signData, pubKey string) error{
   sign, err := base64.StdEncoding.DecodeString(signData)
   if err != nil {
      return err
   }
   public, _ := base64.StdEncoding.DecodeString(pubKey)
   pub, err := x509.ParsePKIXPublicKey(public)
   if err != nil {
      return err
   }
   hash := sha1.New()
   hash.Write([]byte(originalData))
   return rsa.VerifyPKCS1v15(pub.(*rsa.PublicKey), crypto.SHA1, hash.Sum(nil), sign)
}