非对称加密示意图：
在此可以看到，非对称加密是通过两个密钥（公钥-私钥）来实现对数据的加密和解密的。公钥用于加密，私钥用于解密。
RSA公钥和私钥生成：
package main
import (
"crypto/rsa"
"crypto/rand"
"fmt"
"crypto/x509"
"encoding/pem"
"os"
"flag"
)
func RSAKeyGen(bits int) error {
privatekey, err := rsa.GenerateKey(rand.Reader, bits)
if err != nil {
fmt.Println("私钥文件生成失败")
}
fmt.Println("私钥为：", privatekey)
derStream := x509.MarshalPKCS1PrivateKey(privatekey)
block := &pem.Block{
Type:"RSA Private key",
Bytes: derStream,
}
privatefile, err := os.Create("myprivatekey.pem")
defer privatefile.Close()
err = pem.Encode(privatefile, block)
if err != nil {
fmt.Println(err.Error())
return err
}
publickey := &privatekey.PublicKey;
fmt.Println("公钥为：", publickey)
derpkix, err := x509.MarshalPKIXPublicKey(publickey)
block = &pem.Block{
Type:"RSA Public key",
Bytes: derpkix,
}
if err != nil {
fmt.Println(err.Error())
return err
}
publickfile, err := os.Create("mypublic.pem")
defer publickfile.Close()
err = pem.Encode(publickfile, block)
if err != nil {
fmt.Println(err.Error())
return err
}
return nil
}
func main() {
var bits int
flag.IntVar(&bits,"b",1024,"密码默认长度1024")
err := RSAKeyGen(bits)
if err != nil{
fmt.Println("RSA密码文件生成失败")
}
fmt.Println("RSA密码生成成功")
}
利用公钥和私钥进行加密解密：
package main
import (
"encoding/pem"
"errors"
"crypto/x509"
"crypto/rsa"
"crypto/rand"
"fmt"
"encoding/base64"
"os"
)
var publickey = FileLoad("mypublic.pem")
var privatekey = FileLoad("myprivatekey.pem")
func RSAEncrypt(orgidata []byte) ([]byte, error) {
block, _ := pem.Decode(publickey)
if block == nil {
return nil, errors.New("public key is bad")
}
pubInterface, err := x509.ParsePKIXPublicKey(block.Bytes)
if err != nil {
return nil, err
}
pub := pubInterface.(*rsa.PublicKey)
return rsa.EncryptPKCS1v15(rand.Reader, pub, orgidata)//加密
}
func RSADecrypt(cipertext []byte) ([]byte, error) {
block, _ := pem.Decode(privatekey)
if block == nil {
return nil, errors.New("public key is bad")
}
priv, err := x509.ParsePKCS1PrivateKey(block.Bytes)
if err != nil {
return nil, err
}
return rsa.DecryptPKCS1v15(rand.Reader, priv, cipertext)
}
func FileLoad(filepath string) ([]byte) {
privatefile,err := os.Open(filepath)
defer privatefile.Close()
if err!=nil{
return nil
}
privateKey := make([]byte,2048)
num,err := privatefile.Read(privateKey)
return privateKey[:num]
}
func main() {
var data []byte
var err error
data, err = RSAEncrypt([]byte("QQ77025077"))
if err != nil {
fmt.Println("错误", err)
}
fmt.Println("加密：", base64.StdEncoding.EncodeToString(data))
origData, err := RSADecrypt(data)//解密
if err != nil {
fmt.Println("错误", err)
}
fmt.Println("解密:", string(origData))
//pk := FileLoad("myprivatekey.pem")
//fmt.Println(string(pk))
}