安恒2020四月赛

Posted on 2020-04-25 Edited on 2021-01-16 In CTF , WP Views:

安恒2020四月赛

只会做做简单题混混分😢

web1

<?php

show_source("index.php");
function write ($data) {
	return str_replace(chr(0) . '*' . chr(0), '\0\0\0', $data);
}

function read ($data) {
	return str_replace('\0\0\0', chr(0) . '*' . chr(0), $data);
}

class A {
	public $username;
	public $password;

	function __construct ($a, $b) {
		$this->username = $a;
		$this->password = $b;
	}
}

class B {
	public $b ="gpy";
	function __destruct () {
		$c = 'a' . $this->b;
		echo $c;
	}
}

class C {
	public $c;

	function __toString () {
		//flag.php
		echo file_get_contents($this->c);
		return 'nice';
	}
}
$a = new A($_GET['a'],$_GET['b']);
$b = unserialize(read(write(serialize($a))));
function read ($data) {
	return str_replace('\0\0\0', chr(0) . '*' . chr(0), $data);
}