公钥加密 私钥解密

// 公钥加密-分段

func RsaEncryptBlock(src, publicKeyByte []byte) (bytesEncrypt []byte, err error) {
    // 解码公钥文件，返回block结构
    // The encoded form is:
    //    -----BEGIN Type-----
    //    Headers
    //    base64-encoded Bytes
    //    -----END Type-----
	block, _ := pem.Decode(publicKeyByte)
	if block == nil {
		return nil, errors.New("Decode PublicKey Fail")
	}
	
	// 解析 PKIX 格式的公钥，返回 *rsa.PublicKey, *dsa.PublicKey, *ecdsa.PublicKey 等格式的struct
	publicKey, err := x509.ParsePKIXPublicKey(block.Bytes)
	if err != nil {
		return nil, err
	}
	
	//根据自己具体使用的格式做推测
	pub, keySize :=  publicKey.(*rsa.PublicKey), publicKey.(*rsa.PublicKey).Size()
	srcSize := len(src)
	
    fmt.Println("密钥长度：", keySize, "\t明文长度：\t", srcSize)
	//单次加密的长度需要减掉padding的长度，PKCS1为11
	

    // 按需加密
	offSet, once := 0, keySize-11
	buffer := bytes.Buffer{}
	for offSet < srcSize {
		endIndex := offSet + once
		if endIndex > srcSize {
			endIndex = srcSize
		}
		// 加密一部分
		bytesOnce, err := rsa.EncryptPKCS1v15(myrand.Reader, pub, src[offSet:endIndex])
		if err != nil {
			return nil, err
		}
		buffer.Write(bytesOnce)
		offSet = endIndex
	}
	bytesEncrypt = buffer.Bytes()
	return
}

**
私钥解密-分段
 */
func RsaDecryptBlock(src, privateKeyByte []byte) (bytesDecrypt  []byte, err error) {
	block, _ := pem.Decode(privateKeyByte)
	if block == nil {
		return nil, errors.New("Decode PrivateKey Fail")
	}
	
	// 注意格式 PKCS8 / PKCS1
	privateKey, err := x509.ParsePKCS8PrivateKey(block.Bytes)
	if err != nil {
		return nil, err
	}
	
	private := privateKey.(*rsa.PrivateKey)
	keySize, srcSize := private.Size(), len(src)
	fmt.Println("密钥长度：", keySize, "\t密文长度：\t", srcSize)
	
	var offSet = 0
	var buffer = bytes.Buffer{}
	for offSet < srcSize {
		endIndex := offSet + keySize
		if endIndex > srcSize {
			endIndex = srcSize
		}
		// 解密
		bytesOnce, err := rsa.DecryptPKCS1v15(myrand.Reader, private, src[offSet:endIndex])
		if err != nil {
			return nil, err
		}
		buffer.Write(bytesOnce)
		offSet = endIndex
	}
	bytesDecrypt = buffer.Bytes()
	return
}

hmac_sha256加密

hmac_sha256加密
func HmacSha256(message string, secret string) string {
	key := []byte(secret)
	h := hmac.New(sha256.New, key)
	h.Write([]byte(message))
	return base64.StdEncoding.EncodeToString(h.Sum(nil))  // 转base64str
}