encoding/pem

pem包实现了PEM数据编码（源自保密增强邮件协议）。目前PEM编码主要用于TLS密钥和证书

PEM 编码格式如下

-----BEGIN Type-----
Headers
base64-encoded Bytes
-----END Type-----

编码

func Encode(out io.Writer, b *Block) error

type Block struct {Type    string            // 得自前言的类型（如"RSA PRIVATE KEY"）Headers map[string]string // 可选的头项Bytes   []byte            // 内容解码后的数据，一般是DER编码的ASN.1结构
}

下面我们就以ras加密方式为例,看一个pem编码的实现过程

package mainimport ("crypto/rsa""crypto/rand""fmt""encoding/pem""crypto/x509""os""log""io/ioutil""errors"
)
var privite_key_path = "/Users/xujie/go/src/awesomeProject/main/private.pem"
var public_key_path = "/Users/xujie/go/src/awesomeProject/main/public.pem"func main() {// 生成公钥和私钥generatePublick(generatePrivate())src := []byte(`{"name":"酷走天涯"}`)// 公钥加密cryptoData,error := rsaEncrypt(src)if error != nil {log.Fatal(error)}fmt.Println("加密:",cryptoData)// 私钥解密dst,error := rsaDecrypt(cryptoData)if error != nil {log.Fatal(error)}fmt.Println("解密:",string(dst))
}// 生成私钥
func generatePrivate() *rsa.PrivateKey{privateKey,error :=  rsa.GenerateKey(rand.Reader,2048)if error != nil {fmt.Println(error)}derStream := x509.MarshalPKCS1PrivateKey(privateKey)block := &pem.Block{Type:"RSA PRIVATE KEY",Bytes:derStream}file,error := os.Create(privite_key_path)if error != nil {fmt.Println(error)}error = pem.Encode(file,block)if error != nil {fmt.Println(error)}return privateKey
}// 生成公钥
func generatePublick(privateKey *rsa.PrivateKey){publicKey := privateKey.Public()derStream,error := x509.MarshalPKIXPublicKey(publicKey)if error != nil{fmt.Println(error)}block := &pem.Block{Type:"RSA PUBLIC KEY",Bytes:derStream}file,error := os.Create(public_key_path)if error != nil {fmt.Println(error)}error = pem.Encode(file,block)if error != nil {fmt.Println(error)}
}// 公钥加密
func rsaEncrypt(origData []byte) ([]byte, error) {// 从文件中读取公钥编码字节流file,error := os.Open(public_key_path)if error != nil{log.Fatal(error)}publicKey,error := ioutil.ReadAll(file)if error != nil{log.Fatal(error)}// 解码对应的block块数据block, _ := pem.Decode(publicKey)if block == nil {return nil, errors.New("public key error")}// 获取公钥key值pubInterface, err := x509.ParsePKIXPublicKey(block.Bytes)if err != nil {return nil, err}pub := pubInterface.(*rsa.PublicKey)// 加密数据return rsa.EncryptPKCS1v15(rand.Reader, pub, origData)
}// 私钥解密
func rsaDecrypt(ciphertext []byte) ([]byte, error) {// 从文件中读取私钥pem字节流file,error := os.Open(privite_key_path)if error != nil{log.Fatal(error)}privateKey,error := ioutil.ReadAll(file)if error != nil{log.Fatal(error)}// 解码出对应的block值block, _ := pem.Decode(privateKey)if block == nil {return nil, errors.New("private key error!")}// 获取私钥对象priv, err := x509.ParsePKCS1PrivateKey(block.Bytes)if err != nil {return nil, err}// 解密文件return rsa.DecryptPKCS1v15(rand.Reader, priv, ciphertext)
}

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rsa.GenerateKey(rand.Reader,2048) 2048 是默认的的数据长度,也可以设置其他值