golang數據加解密

package ystEncrypt

import (
	"bytes"
	"crypto/aes"
	"crypto/cipher"
	"encoding/base64"
	"errors"
	"strings"
)

type aesEncrypt struct {
	Key        string //
	IvDefValue string //ivDefValue
}

/**
aesEncrypt初始化
*/
func NewAesEncrypt(Key string, IvDefValue string) *aesEncrypt {
	var a aesEncrypt
	a.Key = Key
	a.IvDefValue = IvDefValue
	return &a
}

/**
數據加密
*/
func (a *aesEncrypt) EncodeData(data string, isBase64 bool, isUrlSafe bool) (string, error) {
	if data == "" {
		return "", errors.New("data  is null")
	}

	key := a.Key
	ivDefValue := a.IvDefValue

	decodeBytesKey, err := base64.StdEncoding.DecodeString(key)
	if err != nil {
		return "", err
	}

	decodeBytesivDefValue, err2 := base64.StdEncoding.DecodeString(ivDefValue)
	if err2 != nil {
		return "", err2
	}

	origData, err3 := a.AesEncrypt([]byte(data), decodeBytesKey, decodeBytesivDefValue)
	if err3 != nil {
		return "", err3
	}
	if isBase64 {
		uEnc := ""
		if isUrlSafe {
			uEnc = base64.URLEncoding.EncodeToString(origData)
			uEnc = strings.Replace(uEnc, "=", "", -1)
		} else {
			uEnc = base64.StdEncoding.EncodeToString(origData)
		}
		return uEnc, nil
	}

	return string(origData), nil
}

/**
數據解密
*/
func (a *aesEncrypt) DecodeData(data string, isBase64 bool, isUrlSafe bool) (string, error) {

	if data == "" {
		return "", errors.New("data  is null")
	}
	decodeBytesivData := []byte{}
	err := *new(error)
	if isBase64 {
		if isUrlSafe {
			decodeBytesivData, err = base64.RawURLEncoding.DecodeString(data)
		} else {
			decodeBytesivData, err = base64.StdEncoding.DecodeString(data)
		}
	} else {
		decodeBytesivData = []byte(data)
	}

	if err != nil {
		return "", err
	}

	key := a.Key
	ivDefValue := a.IvDefValue

	decodeBytesKey, err2 := base64.StdEncoding.DecodeString(key)
	if err2 != nil {
		return "", err2
	}

	decodeBytesivDefValue, err4 := base64.StdEncoding.DecodeString(ivDefValue)
	if err4 != nil {
		return "", err4
	}

	origData, err3 := a.AesDecrypt(decodeBytesivData, decodeBytesKey, decodeBytesivDefValue)
	if err3 != nil {
		return "", err3
	}

	return string(origData), nil
}

/**
字符串替換
*/
func (a *aesEncrypt) UrlDecodeForBase64(str string) string {
	str = strings.Replace(str, "-", "+", -1)
	str = strings.Replace(str, "_", "/", -1)
	return str
}

/**
url安全
*/
func (a *aesEncrypt) UrlEncodeForBase64(str string) string {
	str = strings.Replace(str, "+", "-", -1)
	str = strings.Replace(str, "/", "_", -1)
	str = strings.Replace(str, "=", "", -1)
	return str
}

func (a *aesEncrypt) AesEncrypt(plaintext []byte, key []byte, iv []byte) ([]byte, error) {
	block, err := aes.NewCipher(key)
	if err != nil {
		return nil, errors.New("invalid decrypt key")
	}
	blockSize := block.BlockSize()
	plaintext = a.PKCS5Padding(plaintext, blockSize)
	blockMode := cipher.NewCBCEncrypter(block, iv)

	ciphertext := make([]byte, len(plaintext))
	blockMode.CryptBlocks(ciphertext, plaintext)

	return ciphertext, nil
}

func (a *aesEncrypt) AesDecrypt(ciphertext []byte, key []byte, iv []byte) ([]byte, error) {

	block, err := aes.NewCipher(key)
	if err != nil {
		return nil, errors.New("invalid decrypt key")
	}

	blockSize := block.BlockSize()

	if len(ciphertext) < blockSize {
		return nil, errors.New("ciphertext too short")
	}

	if len(ciphertext)%blockSize != 0 {
		return nil, errors.New("ciphertext is not a multiple of the block size")
	}

	blockModel := cipher.NewCBCDecrypter(block, iv)

	plaintext := make([]byte, len(ciphertext))
	blockModel.CryptBlocks(plaintext, ciphertext)
	plaintext = a.PKCS5UnPadding(plaintext)

	return plaintext, nil
}

func (a *aesEncrypt) PKCS5Padding(src []byte, blockSize int) []byte {
	padding := blockSize - len(src)%blockSize
	padtext := bytes.Repeat([]byte{byte(padding)}, padding)
	return append(src, padtext...)
}

func (a *aesEncrypt) PKCS5UnPadding(src []byte) []byte {
	length := len(src)
	unpadding := int(src[length-1])
	if length-unpadding <= 0 {
		return src
	}
	return src[:(length - unpadding)]
}