Golang加密系列的最后一篇，嗯，RSA涉及的概念太多，弄了好久才搞清楚。。。
代码的结构如下图
PS:StarUML这玩意在Mac上所有连到Interface的线都变成直线了...我很惆怅...
定义一个对外开放的接口
package rsa import "crypto" type Cipher interface { Encrypt(plaintext []byte) ([]byte, error) Decrypt(ciphertext []byte) ([]byte, error) Sign(src []byte, hash crypto.Hash) ([]byte, error) Verify(src []byte, sign []byte, hash crypto.Hash) error } 定义私有的pkcsClient ，实现Cipher接口， PKCS格式的私钥都使用这个client
package rsa import ( "crypto" "crypto/rand" "crypto/rsa" ) type pkcsClient struct { privateKey *rsa.PrivateKey publicKey *rsa.PublicKey } func (this *pkcsClient) Encrypt(plaintext []byte) ([]byte, error) { return rsa.EncryptPKCS1v15(rand.Reader, this.publicKey, plaintext) } func (this *pkcsClient) Decrypt(ciphertext []byte) ([]byte, error) { return rsa.DecryptPKCS1v15(rand.Reader, this.privateKey, ciphertext) } func (this *pkcsClient) Sign(src []byte, hash crypto.Hash) ([]byte, error) { h := hash.New() h.Write(src) hashed := h.Sum(nil) return rsa.SignPKCS1v15(rand.Reader, this.privateKey, hash, hashed) } func (this *pkcsClient) Verify(src []byte, sign []byte, hash crypto.Hash) error { h := hash.New() h.Write(src) hashed := h.Sum(nil) return rsa.VerifyPKCS1v15(this.publicKey, hash, hashed, sign) } 将私钥类型定义成枚举类型
package privatekey type Type int64 const ( PKCS1 Type = iota PKCS8 )
定义一个New/NewDefault函数，用于创建client
package rsa import ( "crypto/rsa" "crypto/x509" "encoding/pem" "errors" "toast/rsa/privatekey" ) //默认客户端，pkcs8私钥格式，pem编码 func NewDefault(privateKey, publicKey string) (Cipher, error) { blockPri, _ := pem.Decode([]byte(privateKey)) if blockPri == nil { return nil, errors.New("private key error") } blockPub, _ := pem.Decode([]byte(publicKey)) if blockPub == nil { return nil, errors.New("public key error") } return New(blockPri.Bytes, blockPub.Bytes, privatekey.PKCS8) } func New(privateKey, publicKey []byte, privateKeyType privatekey.Type) (Cipher, error) { priKey, err := genPriKey(privateKey, privateKeyType) if err != nil { return nil, err } pubKey, err := genPubKey(publicKey) if err != nil { return nil, err } return &pkcsClient{privateKey: priKey, publicKey: pubKey}, nil } func genPubKey(publicKey []byte) (*rsa.PublicKey, error) { pub, err := x509.ParsePKIXPublicKey(publicKey) if err != nil { return nil, err } return pub.(*rsa.PublicKey), nil } func genPriKey(privateKey []byte, privateKeyType privatekey.Type) (*rsa.PrivateKey, error) { var priKey *rsa.PrivateKey var err error switch privateKeyType { case privatekey.PKCS1: { priKey, err = x509.ParsePKCS1PrivateKey([]byte(privateKey)) if err != nil { return nil, err } } case privatekey.PKCS8: { prkI, err := x509.ParsePKCS8PrivateKey([]byte(privateKey)) if err != nil { return nil, err } priKey = prkI.(*rsa.PrivateKey) } default: { return nil, errors.New("unsupport private key type") } } return priKey, nil } 最后，看看如何使用上面的代码来进行加密/解密，签名验签
package rsa_test import ( "crypto" "encoding/base64" "encoding/hex" "fmt" "testing" "toast/rsa" ) var cipher rsa.Cipher func init() { client, err := rsa.NewDefault(`-----BEGIN PRIVATE KEY----- 私钥信息 -----END PRIVATE KEY-----`, `-----BEGIN PUBLIC KEY----- 公钥信息 -----END PUBLIC KEY-----`) if err != nil { fmt.Println(err) } cipher = client } func Test_DefaultClient(t *testing.T) { cp, err := cipher.Encrypt([]byte("测试加密解密")) if err != nil { t.Error(err) } cpStr := base64.URLEncoding.EncodeToString(cp) fmt.Println(cpStr) ppBy, err := base64.URLEncoding.DecodeString(cpStr) if err != nil { t.Error(err) } pp, err := cipher.Decrypt(ppBy) fmt.Println(string(pp)) } func Test_Sign_DefaultClient(t *testing.T) { src := "测试签名验签" signBytes, err := cipher.Sign([]byte(src), crypto.SHA256) if err != nil { t.Error(err) } sign := hex.EncodeToString(signBytes) fmt.Println(sign) signB, err := hex.DecodeString(sign) errV := cipher.Verify([]byte(src), signB, crypto.SHA256) if errV != nil { t.Error(errV) } fmt.Println("verify success") } 关于RSA相关的一些概念，参见我的另一篇博客.pem引发的血案
这里还有一个已经编写好的AES/RSA加解密的包，可以直接引用，github地址：https://github.com/89hmdys/toast
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