// rsa.go

package main

import (

    "crypto/rand"

    "crypto/rsa"

    "crypto/x509"

    "encoding/pem"

    "errors"

    "fmt"

)

// 公钥和私钥可以从文件中读取

var privateKey = []byte(`

-----BEGIN RSA PRIVATE KEY-----

MIICXQIBAAKBgQDZsfv1qscqYdy4vY+P4e3cAtmvppXQcRvrF1cB4drkv0haU24Y

7m5qYtT52Kr539RdbKKdLAM6s20lWy7+5C0DgacdwYWd/7PeCELyEipZJL07Vro7

Ate8Bfjya+wltGK9+XNUIHiumUKULW4KDx21+1NLAUeJ6PeW+DAkmJWF6QIDAQAB

AoGBAJlNxenTQj6OfCl9FMR2jlMJjtMrtQT9InQEE7m3m7bLHeC+MCJOhmNVBjaM

ZpthDORdxIZ6oCuOf6Z2+Dl35lntGFh5J7S34UP2BWzF1IyyQfySCNexGNHKT1G1

XKQtHmtc2gWWthEg+S6ciIyw2IGrrP2Rke81vYHExPrexf0hAkEA9Izb0MiYsMCB

/jemLJB0Lb3Y/B8xjGjQFFBQT7bmwBVjvZWZVpnMnXi9sWGdgUpxsCuAIROXjZ40

IRZ2C9EouwJBAOPjPvV8Sgw4vaseOqlJvSq/C/pIFx6RVznDGlc8bRg7SgTPpjHG

4G+M3mVgpCX1a/EU1mB+fhiJ2LAZ/pTtY6sCQGaW9NwIWu3DRIVGCSMm0mYh/3X9

DAcwLSJoctiODQ1Fq9rreDE5QfpJnaJdJfsIJNtX1F+L3YceeBXtW0Ynz2MCQBI8

9KP274Is5FkWkUFNKnuKUK4WKOuEXEO+LpR+vIhs7k6WQ8nGDd4/mujoJBr5mkrw

DPwqA3N5TMNDQVGv8gMCQQCaKGJgWYgvo3/milFfImbp+m7/Y3vCptarldXrYQWO

AQjxwc71ZGBFDITYvdgJM1MTqc8xQek1FXn1vfpy2c6O

-----END RSA PRIVATE KEY-----

`)

var publicKey = []byte(`

-----BEGIN PUBLIC KEY-----

MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDZsfv1qscqYdy4vY+P4e3cAtmv

ppXQcRvrF1cB4drkv0haU24Y7m5qYtT52Kr539RdbKKdLAM6s20lWy7+5C0Dgacd

wYWd/7PeCELyEipZJL07Vro7Ate8Bfjya+wltGK9+XNUIHiumUKULW4KDx21+1NL

AUeJ6PeW+DAkmJWF6QIDAQAB

-----END PUBLIC KEY-----

`)

// 加密

func RsaEncrypt(origData []byte) ([]byte, error) {

    block, _ := pem.Decode(publicKey)

    if block == nil {

        return nil, errors.New("public key error")

    }

    pubInterface, err := x509.ParsePKIXPublicKey(block.Bytes)

    if err != nil {

        return nil, err

    }

    pub := pubInterface.(*rsa.PublicKey)

    return rsa.EncryptPKCS1v15(rand.Reader, pub, origData)

}

// 解密

func RsaDecrypt(ciphertext []byte) ([]byte, error) {

    block, _ := pem.Decode(privateKey)

    if block == nil {

        return nil, errors.New("private key error!")

    }

    priv, err := x509.ParsePKCS1PrivateKey(block.Bytes)

    if err != nil {

        return nil, err

    }

    return rsa.DecryptPKCS1v15(rand.Reader, priv, ciphertext)

}

func main() {

    data, err := RsaEncrypt([]byte("polaris@studygolang.com"))

    fmt.Println(string(data))

    if err != nil {

        panic(err)

    }

    origData, err := RsaDecrypt(data)

    if err != nil {

        panic(err)

    }

    fmt.Println(string(origData))

}