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const FLAG: &'static str = "UMASS{pL4YZ_s4d_v1oL1n_s4DlY__g0_3a7_50m37hIN_Pl3453}";
use async_std::io;
use async_std::net::{TcpListener, TcpStream};
use async_std::prelude::*;
use async_std::task;
enum ClientMessage {
North,
South,
East,
West,
Unknown,
}
const SERVER_MAP: u8 = 0;
const SERVER_GOTO: u8 = 1;
const SERVER_MESSAGE: u8 = 2;
const MAZE_SIZE: usize = 24;
use maze_generator::ellers_algorithm::EllersGenerator;
use maze_generator::prelude::*;
const AES_KEY: &'static str = "STRINGS NOT HERE";
use openssl::symm::{decrypt, encrypt, Cipher};
use rand::RngCore;
fn my_encrypt(packet: &[u8]) -> Vec<u8> {
let mut rng = rand::thread_rng();
let mut iv = [0 as u8; 16];
rng.fill_bytes(&mut iv);
let cipher = Cipher::aes_128_cbc();
let key = AES_KEY.as_bytes();
let mut data = encrypt(cipher, key, Some(&iv), packet).unwrap();
let mut ciphertext = Vec::from(iv);
ciphertext.append(&mut data);
ciphertext
}
fn my_decrypt(packet: &[u8]) -> Vec<u8> {
let iv = &packet[..16];
let data = &packet[16..];
let cipher = Cipher::aes_128_cbc();
let key = AES_KEY.as_bytes();
let plaintext = decrypt(cipher, key, Some(iv), data).unwrap();
plaintext
}
fn new_map() -> (Vec<Vec<u8>>, (i32, i32)) {
let mut generator = EllersGenerator::new(None);
let maze = generator.generate((MAZE_SIZE / 3) as i32, (MAZE_SIZE / 3) as i32);
let mut map = vec![vec![0; MAZE_SIZE]; MAZE_SIZE];
for x in 0..MAZE_SIZE {
for y in 0..MAZE_SIZE {
if x == 0 || x == MAZE_SIZE - 1 || y == 0 || y == MAZE_SIZE - 1 {
map[y][x] = 1;
}
}
}
for x in 0..MAZE_SIZE / 3 {
for y in 0..MAZE_SIZE / 3 {
if let Some(field) = maze.get_field(&Coordinates::new(x as i32, y as i32)) {
if !field.has_passage(&Direction::North) {
map[(y * 3)][(x * 3) + 1] = 1;
}
if !field.has_passage(&Direction::South) {
map[(y * 3) + 2][(x * 3) + 1] = 1;
}
if !field.has_passage(&Direction::East) {
map[(y * 3) + 1][(x * 3) + 2] = 1;
}
if !field.has_passage(&Direction::West) {
map[(y * 3) + 1][(x * 3)] = 1;
}
}
}
}
map[(maze.goal.y * 3 + 1) as usize][(maze.goal.x * 3 + 1) as usize] = 2;
(map, (maze.start.x * 3 + 2, maze.start.y * 3 + 2))
}
async fn send_map(map: &Vec<Vec<u8>>, writer: &mut TcpStream) -> std::io::Result<usize> {
// Serialize map.
let mut packet = vec![SERVER_MAP];
let mut buf = [0 as u8; MAZE_SIZE * MAZE_SIZE];
for y in 0..MAZE_SIZE {
for x in 0..MAZE_SIZE {
buf[y * MAZE_SIZE + x] = map[x][y];
}
}
packet.append(&mut Vec::from(buf));
let mut ciphertext = my_encrypt(&packet);
let mut packet = Vec::from((ciphertext.len() as u64).to_be_bytes());
packet.append(&mut ciphertext);
writer.write(&packet).await
}
async fn send_goto(position: (i32, i32), writer: &mut TcpStream) -> std::io::Result<usize> {
let mut packet = vec![SERVER_GOTO];
let mut succ = Vec::from(position.0.to_be_bytes());
packet.append(&mut succ);
let mut succ = Vec::from(position.1.to_be_bytes());
packet.append(&mut succ);
let mut ciphertext = my_encrypt(&packet);
let mut packet = Vec::from((ciphertext.len() as u64).to_be_bytes());
packet.append(&mut ciphertext);
writer.write(&packet).await
}
async fn send_message(msg: String, writer: &mut TcpStream) -> std::io::Result<usize> {
let mut packet = vec![SERVER_MESSAGE];
packet.append(&mut Vec::from(msg.as_bytes()));
let mut ciphertext = my_encrypt(&packet);
let mut packet = Vec::from((ciphertext.len() as u64).to_be_bytes());
packet.append(&mut ciphertext);
writer.write(&packet).await
}
fn deserialize_client_message(buf: &[u8]) -> ClientMessage {
ClientMessage::Unknown
}
use std::convert::TryInto;
use std::iter;
async fn process(stream: TcpStream) -> io::Result<()> {
println!("Accepted from: {}", stream.peer_addr()?);
// Two buffers.
let mut recv = [0 as u8; 1024];
let mut send = [0 as u8; 1024];
let mut reader = stream.clone();
let mut writer = stream;
let mut map = vec![];
let mut position = (2, 2);
let mut level: i32 = 1;
let mut needs_map = true;
loop {
if needs_map {
let (new_map, new_position) = new_map();
map = new_map;
position = new_position;
send_map(&map, &mut writer).await?;
send_goto(position, &mut writer).await?;
needs_map = false;
}
if let Ok(n) = reader.read(&mut recv).await {
let encrypted_length = u64::from_be_bytes((&recv[..8]).try_into().unwrap()) as usize;
let packet = my_decrypt(&recv[8..8 + encrypted_length]);
match packet[0] {
1 => {
let tile = map[(position.1 + 1) as usize][position.0 as usize];
if tile == 0 {
position.1 += 1;
} else if tile == 2 {
level += 1;
send_message(format!("Noice, level {}", level), &mut writer).await;
needs_map = true;
if level == 25 {
send_message(format!("Congratulations nerd, you just wasted a weekend on this. Here's your stupid flag: {}. Hope it was worth it.", FLAG), &mut writer).await;
}
}
}
4 => {
let tile = map[(position.1 - 1) as usize][position.0 as usize];
if tile == 0 {
position.1 -= 1;
} else if tile == 2 {
level += 1;
send_message(format!("Noice, level {}", level), &mut writer).await;
needs_map = true;
if level == 25 {
send_message(format!("Congratulations nerd, you just wasted a weekend on this. Here's your stupid flag: {}. Hope it was worth it.", FLAG), &mut writer).await;
}
}
}
3 => {
let tile = map[position.1 as usize][(position.0 - 1) as usize];
if tile == 0 {
position.0 -= 1;
} else if tile == 2 {
level += 1;
send_message(format!("Noice, level {}", level), &mut writer).await;
needs_map = true;
if level == 25 {
send_message(format!("Congratulations nerd, you just wasted a weekend on this. Here's your stupid flag: {}. Hope it was worth it.", FLAG), &mut writer).await;
}
}
}
2 => {
let tile = map[position.1 as usize][(position.0 + 1) as usize];
if tile == 0 {
position.0 += 1;
} else if tile == 2 {
level += 1;
send_message(format!("Noice, level {}", level), &mut writer).await;
needs_map = true;
if level == 25 {
send_message(format!("Congratulations nerd, you just wasted a weekend on this. Here's your stupid flag: {}. Hope it was worth it.", FLAG), &mut writer).await;
}
}
}
_ => {
break;
}
}
send_goto(position, &mut writer).await?;
}
}
Ok(())
}
fn main() -> io::Result<()> {
task::block_on(async {
// let listener = TcpListener::bind("127.0.0.1:8080").await?;
let listener = TcpListener::bind("0.0.0.0:8080").await?;
println!("Listening on {}", listener.local_addr()?);
let mut incoming = listener.incoming();
while let Some(stream) = incoming.next().await {
let stream = stream?;
task::spawn(async {
process(stream).await.unwrap();
});
}
Ok(())
})
}
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