微盾PHP脚本加密专家解密算法
neeaosblog
今天工作中某合作商拿过来代码让检查安全，一看代码加密了，比较汗，类似下面代码：
<?php // This file is protected by copyright law & provided under license. Copyright(C) 2005-2009 www.vidun.com, All rights reserved. $OOO0O0O00=__FILE__;$OOO000000=urldecode(%74%68%36%73%62%65%68%71%6c%61%34%63%6f%5f%73%61%64%66%70%6e%72);$OO00O0000=28;$OOO0000O0=$OOO000000{4}.$OOO000000{9}.$OOO000000{3}.$OOO000000{5};$OOO0000O0.=$OOO000000{2}.$OOO000000{10}.$OOO000000{13}.$OOO000000{16};$OOO0000O0.=$OOO0000O0{3}.$OOO000000{11}.$OOO000000{12}.$OOO0000O0{7}.$OOO000000{5};$O0O0000O0=OOO0000O0;eval(($$O0O0000O0(JE9PME9PMDAwMD0kT09PMDAwMDAwezE3fS4kT09PMDAwMDAwezEyfS4kT09PMDAwMDAwez
E4fS4kT09PMDAwMDAwezV9LiRPT08wMDAwMDB7MTl9O2lmKCEwKSRPMDAwTzBPMDA9JE9PME9PMDAwMCgkT09PME8wTzAwLCdyYicpOyRPTzBPTzAw
ME89JE9PTzAwMDAwMHsxN30uJE9PTzAwMDAwMHsyMH0uJE9PTzAwMDAwMHs1fS4kT09PMDAwMDAwezl9LiRPT08wMDAwMDB7MTZ9OyRPTzBPTzAwTzA
9JE9PTzAwMDAwMHsxNH0uJE9PTzAwMDAwMHswfS4kT09PMDAwMDAwezIwfS4kT09PMDAwMDAwezB9LiRPT08wMDAwMDB7MjB9OyRPTzBPTzAwME8oJE8w
MDBPME8wMCwxMjU5KTskT08wME8wME8wPSgkT09PMDAwME8wKCRPTzBPTzAwTzAoJE9PME9PMDAwTygkTzAwME8wTzAwLDM4MCksJ0VudGVyeW91d2to
UkhZS05XT1VUQWFCYkNjRGRGZkdnSWlKakxsTW1QcFFxU3NWdlh4WnowMTIzNDU2Nzg5Ky89JywnQUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVphYmNk
ZWZnaGlqa2xtbm9wcXJzdHV2d3h5ejAxMjM0NTY3ODkrLycpKSk7ZXZhbCgkT08wME8wME8wKTs=)));return;?> kr9NHenNHenNHe1zfukgFMaXdoyjcUImb19oUAxyb18mRtwmwJ4LT09NHr8XTzEXRJwmwJXPkr9NTzEXHenNHtILT08XT08XHr8XhtONTznNTzEXHr8Pkr8XHenNHr
8XHtXLT08XHr8XHeEXhUXmOB50cbk5d3a3D2iUUylRTlfNaaOnCAkJW2YrcrcMO2fkDApQToxYdanXAbyTF1c2BuiDGjExHjH0YTC3KeLqRz0mRtfnWLYrOAc
uUrlhU0xYTL9WAakTayaBa1icBMyJC2OlcMfPDBpqdo1Vd3nxFmY0fbc3Gul6HerZHzW1YjF4KUSvkZLphUL7cMYSd3YlhtONHeEXTznNHeEpK2a2CBXPkr9N
HenNHenNHtL7eWplC2ivwunPFolVcM8PhTSYtI== 很明显，是使用了某种PHP代码混淆工具混淆了下，Google一把，原来是使用的微盾PHP脚本加密专家加密的，网上搜了下，没找到免费的解密工具，于是乎，自己就研究了下，写了个解密算法，share下，给遇到同样问题的朋友一个方便。
另外需要说明的是，我测试，本地解密出来的代码可以阅读的，由于代码混淆过，可能还原出来的有些地方和原代码有出入，有需要可自行修改之。
<?php
/***********************************
*威盾PHP加密专家解密算法 By：Neeao
*http://Neeao.com
*2009-09-10
***********************************/
$filename="install.php";//要解密的文件
$lines = file($filename);//0,1,2行
//第一次base64解密
$content="";
if(preg_match("/O0O0000O0(.*)/",$lines[1],$y))
{
$content=str_replace("O0O0000O0(","",$y[0]);
$content=str_replace(")","",$content);
$content=base64_decode($content);
}
//第一次base64解密后的内容中查找密钥
$decode_key="";
if(preg_match("/),.*,/",$content,$k))
{
$decode_key=str_replace("),","",$k[0]);
$decode_key=str_replace(",","",$decode_key);
}
//截取文件加密后的密文
$Secret=substr($lines[2],380);
//echo $Secret;
//直接还原密文输出
echo "<?php ".base64_decode(strtr($Secret,$decode_key,ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/))."?>";
?>