# b01lers CTF 2020 – Welcome to Earth
* **Category:** web
* **Points:** 100
## Challenge
> This was supposed to be my weekend off, but noooo, you got me out here,
> draggin' your heavy ass through the burning desert, with your dreadlocks
> sticking out the back of my parachute. You gotta come down here with an
> attitude, actin' all big and bad. And what the hell is that smell? I coulda
> been at a barbecue, but I ain't mad.
>
> http://web.ctf.b01lers.com:1000/
## Solution
The webpage contains the following HTML.
```html
Welcome to Earth
AMBUSH!
You've gotta escape!
```
So you can discover the `http://web.ctf.b01lers.com:1000/chase/` endpoint.
```html
Welcome to Earth
CHASE!
You managed to chase one of the enemy fighters, but there's a wall coming
up fast!
```
So you can discover the `http://web.ctf.b01lers.com:1000/leftt/` endpoint.
```html
Welcome to Earth
SHOOT IT
You've got the bogey in your sights, take the shot!
```
So you can discover the `http://web.ctf.b01lers.com:1000/shoot/` endpoint.
```html
Welcome to Earth
YOU SHOT IT DOWN!
Well done! You also crash in the process
```
So you can discover the `http://web.ctf.b01lers.com:1000/door/` endpoint.
```html
Welcome to Earth
YOU APPROACH THE ALIEN CRAFT!
How do you get inside?
```
So you can discover the `http://web.ctf.b01lers.com:1000/static/js/door.js`
file.
```javascript
function check_door() {
var all_radio = document.getElementById("door_form").elements;
var guess = null;
for (var i = 0; i < all_radio.length; i++)
if (all_radio[i].checked) guess = all_radio[i].value;
rand = Math.floor(Math.random() * 360);
if (rand == guess) window.location = "/open/";
else window.location = "/die/";
}
```
So you can discover the `http://web.ctf.b01lers.com:1000/open/` endpoint.
```html
Welcome to Earth
YOU FOUND THE DOOR!
How do you open it?
```
So you can discover the
`http://web.ctf.b01lers.com:1000/static/js/open_sesame.js` file.
```javascript
function sleep(ms) {
return new Promise(resolve => setTimeout(resolve, ms));
}
function open(i) {
sleep(1).then(() => {
open(i + 1);
});
if (i == 4000000000) window.location = "/fight/";
}
```
So you can discover the `http://web.ctf.b01lers.com:1000/fight/` endpoint.
```html
Welcome to Earth
AN ALIEN!
What do you do?
```
So you can discover the `http://web.ctf.b01lers.com:1000/static/js/fight.js`
file.
```javascript
// Run to scramble original flag
//console.log(scramble(flag, action));
function scramble(flag, key) {
for (var i = 0; i < key.length; i++) {
let n = key.charCodeAt(i) % flag.length;
let temp = flag[i];
flag[i] = flag[n];
flag[n] = temp;
}
return flag;
}
function check_action() {
var action = document.getElementById("action").value;
var flag = ["{hey", "_boy", "aaaa", "s_im", "ck!}", "_baa", "aaaa", "pctf"];
// TODO: unscramble function
}
```
So the flag is the following.
```
pctf{hey_boys_im_baaaaaaaaaack!}
```
Original writeup (https://github.com/m3ssap0/CTF-
Writeups/blob/master/b01lers%20CTF%202020/Welcome%20to%20Earth/README.md).