PHP对称加密算法（DES/AES）类的实现代码

<?php  
header('Content-Type:text/html;Charset=utf-8;');  
  
include "xcrypt.php";  
  
echo '<pre>';  
//////////////////////////////////////  
$a = isset($_GET['a']) ? $_GET['a'] : '测试123';  
  
//密钥  
$key = '12345678123456781234567812345678'; //256 bit  
$key = '1234567812345678'; //128 bit  
$key = '12345678'; //64 bit  
  
//设置模式和IV  
$m = new Xcrypt($key, 'cbc', 'auto');  
  
//获取向量值  
echo '向量：';  
var_dump($m->getIV());  
  
//加密  
$b = $m->encrypt($a, 'base64');  
//解密  
$c = $m->decrypt($b, 'base64');  
  
echo '加密后：';  
var_dump($b);  
echo '解密后：';  
var_dump($c);  
  
/////////////////////////////////////////  
echo '</pre>';