话题排版

golang实现加密解密的库很多, 这里使用的是aes库+base64库来实现.
使用时,需要指定一个私钥,来进行加解密.

上代码:
```
package main

import (
	"bytes"
	"crypto/aes"
	"crypto/cipher"
	"encoding/base64"
	"fmt"
)

type AesCrypt struct {
	Key   []byte
	Text  []byte
	crypt string
}

func (t *AesCrypt) PKCS5Padding(cipherText []byte, blockSize int) []byte {
	padding := blockSize - len(cipherText)%blockSize
	padText := bytes.Repeat([]byte{byte(padding)}, padding)
	return append(cipherText, padText...)
}

func (t *AesCrypt) PKCS5UnPadding(data []byte) []byte {
	length := len(data)
	unPadding := int(data[length-1])
	return data[:(length - unPadding)]
}

func (t *AesCrypt) encrypt() (string, error) {
	block, err := aes.NewCipher(t.Key)
	if err != nil {
		return "", err
	}

blockSize := block.BlockSize()
	t.Text = t.PKCS5Padding(t.Text, blockSize)

blockMode := cipher.NewCBCEncrypter(block, t.Key[:blockSize])
	data := make([]byte, len(t.Text))
	blockMode.CryptBlocks(data, t.Text)

return base64.StdEncoding.EncodeToString(data), nil
}

func (t *AesCrypt) decrypt() ([]byte, error) {
	crypted, err := base64.StdEncoding.DecodeString(t.crypt)
	if err != nil {
		return nil, err
	}

block, err := aes.NewCipher(t.Key)
	if err != nil {
		return nil, err
	}

blockSize := block.BlockSize()
	blockMode := cipher.NewCBCDecrypter(block, t.Key[:blockSize])
	data := make([]byte, len(crypted))
	blockMode.CryptBlocks(data, crypted)
	data = t.PKCS5UnPadding(data)
	return data, nil
}

func main() {

key := []byte("12345678123456cc") //私钥
	word := []byte("this is test!")   //要加密的字符串

var aesCrypt AesCrypt
	//设置key
	aesCrypt.Key = key

//加密
	aesCrypt.Text = word
	crypt, err := aesCrypt.encrypt()
	if err != nil {
		fmt.Println(err)
		return
	}
	fmt.Printf("加密后:%vn", crypt)

//解密
	aesCrypt.crypt = crypt
	word, err = aesCrypt.decrypt()
	if err != nil {
		fmt.Println(err)
		return
	}
	fmt.Printf("解密后:%sn", word)
}

```

输出:

```
加密后:6/soAEkh3oVaIZkABcwjJQ==
解密后:this is test!
```