简介

在一些应用中，需要加密解密，增加安全性。

RSA是目前使用最广泛的公钥密码体制之一。

代码

定义一个rsa的包，然后就直接调用这个包

package rsa
?
import (
    "crypto/rand"
    "crypto/rsa"
    "crypto/x509"
    "encoding/base64"
    "encoding/pem"
    "fmt"
    "io/ioutil"
    "os"
?
    "github.com/pkg/errors"
)
?
// Key rsa密钥对
type Key struct {
    PrivateKey *rsa.PrivateKey
    PublicKey  *rsa.PublicKey
}
?
// LoadKey 加载RSA
func LoadKey(privateKeyPath, publicKeyPath string) (key Key, err error) {
    privateKey, err := ioutil.ReadFile(privateKeyPath)
    if err != nil {
        panic(err)
    }
    block, _ := pem.Decode(privateKey)
    if block == nil {
        err = errors.New("private key error")
        return
    }
    priv, err := x509.ParsePKCS1PrivateKey(block.Bytes)
    if err != nil {
        err = errors.Wrap(err, fmt.Sprintf("Parse private key  error:%s", err))
        return
    }
    publicKey, err := ioutil.ReadFile(publicKeyPath)
    if err != nil {
        return
    }
    block, _ = pem.Decode(publicKey)
    if block == nil {
        err = errors.New("public key error")
        return
    }
    public, err := x509.ParsePKIXPublicKey(block.Bytes)
    if err != nil {
        err = errors.Wrap(err, fmt.Sprintf("Parse public key  error:%s", err))
        return
    }
    publicKeyContent, ok := public.(*rsa.PublicKey)
    if !ok {
        err = errors.New("inviliad public key")
        return
    }
    key.PrivateKey = priv
    key.PublicKey = publicKeyContent
    return
}
?
// GenKey 生产密钥对
func GenKey(bits int) (key Key, err error) {
    privateKey, err := rsa.GenerateKey(rand.Reader, bits)
    if err != nil {
        return
    }
    key.PrivateKey = privateKey
    // 生成公钥
    publicKey := &privateKey.PublicKey
    key.PublicKey = publicKey
    return
}
?
// GenKeyFile 生产密钥对文件
func GenKeyFile(bits int, privateKeyPath, publicKeyPath string) error {
    privateKey, err := rsa.GenerateKey(rand.Reader, bits)
    if err != nil {
        return err
    }
    derStream := x509.MarshalPKCS1PrivateKey(privateKey)
    block := &pem.Block{
        Type:  "RSA PRIVATE KEY",
        Bytes: derStream,
    }
    file, err := os.Create(privateKeyPath)
    if err != nil {
        return err
    }
    err = pem.Encode(file, block)
    if err != nil {
        return err
    }
    // 生成公钥文件
    publicKey := &privateKey.PublicKey
    derPkix, err := x509.MarshalPKIXPublicKey(publicKey)
    if err != nil {
        return err
    }
    block = &pem.Block{
        Type:  "RSA PUBLIC KEY",
        Bytes: derPkix,
    }
    file, err = os.Create(publicKeyPath)
    if err != nil {
        return err
    }
    err = pem.Encode(file, block)
    if err != nil {
        return err
    }
    return nil
}
?
// Decrypt rsa解密
func (key *Key) Decrypt(ciphertext []byte) (content []byte, err error) {
    content, err = rsa.DecryptPKCS1v15(rand.Reader, key.PrivateKey, ciphertext)
    return
}
?
// DecryptBase64 rsa解密
func (key *Key) DecryptBase64(encryptPwd string) (content []byte, err error) {
    ciphertext, err := base64.StdEncoding.DecodeString(encryptPwd)
    if err != nil {
        return
    }
    content, err = rsa.DecryptPKCS1v15(rand.Reader, key.PrivateKey, ciphertext)
    return
}
?
// Encrypt 加密密文
func (key *Key) Encrypt(content string) (encodeConent []byte, err error) {
    encodeConent, err = rsa.EncryptPKCS1v15(rand.Reader, key.PublicKey, []byte(content))
    return
}
?

测试

GenKeyFile 函数可以产生对应的密钥对，使用的时候只要加载对应的密钥对就可以开始使用了。

package main
?
import (
    "fmt"
    "rsa"
)
?
func main() {
    privateKeyPath := "/tmp/private.pem"
    publicKeyPath := "/tmp/public.pem"
    rsaKey, err := rsa.LoadKey(privateKeyPath, publicKeyPath)
    if err != nil {
        fmt.Println(err)
        return
    }
    a, err := rsaKey.Encrypt("root")
    if err != nil {
        fmt.Println(err)
        return
    }
    content, err := rsaKey.Decrypt(a)
    if err != nil {
        fmt.Println(err)
        return
    }
    fmt.Println(string(content))
    content, err = rsaKey.DecryptBase64("C+qqN53012tg44VjDDRtrJzQ/I6UMpRCVD7GR9Wv6AK6M/LjWy62XbECKURAw0LMfTKjqJTp7PSPFeAkpt22xHoZnkGXjVJ+6jU+YaI8glMb26Mk/G9QVbC+bBQ7fFW7+KqBjCnDm+aSYEqbV2zadk1RCUX/B/uDUQZK5hyliS0=")
    fmt.Println(string(content), err)
}
?