https://ctf.bugku.com/challenges/detail/id/83.html
http://host:port/index.php.bak
<?php
/**
* Created by PhpStorm.
* User: Norse
* Date: 2017/8/6
* Time: 20:22
*/
include_once "flag.php";
ini_set("display_errors", 0);
$str = strstr($_SERVER['REQUEST_URI'], '?');
$str = substr($str,1);
$str = str_replace('key','',$str);
parse_str($str);
echo md5($key1);
echo md5($key2);
if(md5($key1) == md5($key2) && $key1 !== $key2){
echo $flag."取得flag";
}
?>