lottery
- dirsearch扫描了一下 发现git文件 猜测.git 泄露
- 既然是git泄露 Githack下载源码
- 不着急看源码,先看看网页是干嘛的 我的火狐好像出了点问题 不能注册账号
- 这次用Google做题
- 网页大概就是起初你有20元 类似花钱买彩票 买中几位数 给你多少钱 当你的账户有9990000
- 你就能娶老婆(flag)了
- 买了几次血本无归 (不能赌博)
- 审计一下代码吧 主要代码就是这给api.php
?php
require_once('config.php');
header('Content-Type: application/json');
function response($resp){
die(json_encode($resp));
}
function response_error($msg){
$result = ['status'=>'error'];
$result['msg'] = $msg;
response($result);
}
function require_keys($req, $keys){
foreach ($keys as $key) {
if(!array_key_exists($key, $req)){
response_error('invalid request');
}
}
}
function require_registered(){
if(!isset($_SESSION['name']) || !isset($_SESSION['money'])){
response_error('register first');
}
}
function require_min_money($min_money){
if(!isset($_SESSION['money'])){
response_error('register first');
}
$money = $_SESSION['money'];
if($money < 0){
$_SESSION = array();
session_destroy();
response_error('invalid negative money');
}
if($money < $min_money){
response_error('you don\' have enough money');
}
}
if($_SERVER["REQUEST_METHOD"] != 'POST' || !isset($_SERVER["CONTENT_TYPE"]) || $_SERVER["CONTENT_TYPE"] != 'application/json'){
response_error('please post json data');
}
$data = json_decode(file_get_contents('php://input'), true);
if(json_last_error() != JSON_ERROR_NONE){
response_error('invalid json');
}
require_keys($data, ['action']);
function random_num(){
do {
$byte = openssl_random_pseudo_bytes(10, $cstrong);
$num = ord($byte);
} while ($num >= 250);
if(!$cstrong){
response_error('server need be checked, tell admin');
}
$num /= 25;
return strval(floor($num));
}
function random_win_nums(){
$result = '';
for($i=0; $i<7; $i++){
$result .= random_num();
}
return $result;
}
function buy($req){
require_registered();
require_min_money(2);
$money = $_SESSION['money'];
$numbers = $req['numbers'];
$win_numbers = random_win_nums();
$same_count = 0;
for($i=0; $i<7; $i++){
if($numbers[$i] == $win_numbers[$i]){
$same_count++;
}
}
switch ($same_count) {
case 2:
$prize = 5;
break;
case 3:
$prize = 20;
break;
case 4:
$prize = 300;
break;
case 5:
$prize = 1800;
break;
case 6:
$prize = 200000;
break;
case 7:
$prize = 5000000;
break;
default:
$prize = 0;
break;
}
$money += $prize - 2;
$_SESSION['money'] = $money;
response(['status'=>'ok','numbers'=>$numbers, 'win_numbers'=>$win_numbers, 'money'=>$money, 'prize'=>$prize]);
}
function flag($req){
global $flag;
global $flag_price;
require_registered();
$money = $_SESSION['money'];
if($money < $flag_price){
response_error('you don\' have enough money');
} else {
$money -= $flag_price;
$_SESSION['money'] = $money;
$msg = 'Here is your flag: ' . $flag;
response(['status'=>'ok','msg'=>$msg, 'money'=>$money]);
}
}
function register($req){
$name = $req['name'];
$_SESSION['name'] = $name;
$_SESSION['money'] = 20;
response(['status'=>'ok']);
}
switch ($data['action']) {
case 'buy':
require_keys($data, ['numbers']);
buy($data);
break;
case 'flag':
flag($data);
break;
case 'register':
require_keys($data, ['name']);
register($data);
break;
default:
response_error('invalid request');
break;
function buy($req){
require_registered();
require_min_money(2);
$money = $_SESSION['money'];
$numbers = $req['numbers'];
$win_numbers = random_win_nums();
$same_count = 0;
for($i=0; $i<7; $i++){
if($numbers[$i] == $win_numbers[$i]){
$same_count++;
}
}
switch ($same_count) {
case 2:
$prize = 5;
break;
case 3:
$prize = 20;
break;
case 4:
$prize = 300;
break;
case 5:
$prize = 1800;
break;
case 6:
$prize = 200000;
break;
case 7:
$prize = 5000000;
break;
default:
$prize = 0;
break;
}
$money += $prize - 2;
$_SESSION['money'] = $money;
response(['status'=>'ok','numbers'=>$numbers, 'win_numbers'=>$win_numbers, 'money'=>$money, 'prize'=>$prize]);
}
- numbers[i] == win_numbers[i]) 使用的是弱比较来进行判断
- php在弱比较的时候有以下漏洞
if($numbers[$i] == $win_numbers[$i]),
0=='0'
0 == 'abcdefg'
0 === 'abcdefg'
1 == '1abcdef'
- 所以我们买一次彩票抓包
- 用[true,true,true,true,true,true,true,true]去获取巨大金额
- 购买flag