<?php
session_start();
//假设用户登陆成功获得了以下用户数据
$userinfo = array(
    'uid'=> 10000,
    'name'=>'spark',
    'email'=>'spark@imooc.com',
    'sex'=>'man',
    'age'=>'18'
);
header("content-tpye:text/html;charset=utf-8");
/*将用户信息保存到session中*/
$_SESSION['uid']=$userinfo['uid'];
$_SESSION['name']=$userinfo['name'];
$_SESSION['userinfo']=$userinfo;
//将用户数据保存懂啊cookie中的一个简单方法
$secureKey='imooc';//加密密钥
$str=serialize($userinfo);//将用户信息序列化
//用户信息加密前
$str=base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256,md5($secureKey),$str,MCRYPT_MODE_ECB));
//用户信息加密后
//将加密后的用户数据存储到cookie中
setcookie('userinfo',$str);
//当需要使用时进行解密
$str=mcrypt_decrypt(MCRYPT_RIJNDAEL_256,md5($secureKey),base64_decode($str),MCRYPT_MODE_ECB);
$uinfo=unserialize($str);
echo "解密后的用户信息：<br>";
print_r($uinfo);

结果报错，显示

PHP Fatal error:  Uncaught Error: Call to undefined function mcrypt_encrypt() in D:\Demo\Session control08.php:20

Stack trace:

#0 {main}

  thrown in D:\Demo\Session control08.php on line 20

Fatal error: Uncaught Error: Call to undefined function mcrypt_encrypt() in D:\Demo\Session control08.php:20

Stack trace:

#0 {main}

  thrown in D:\Demo\Session control08.php on line 20

进程已结束,退出代码255