# NetOn CTF 2021 - PawN PawN

Cryptography – 188 pts (29 solves) – Chall author: eljoselillo7

Some morse and chess board encodings.

## Solution

This challenge provides us with two files, an WAV sound file and a password protected zip file. The WAV file clearly contains morse code that says

the zip password is 75757575


With this, we unlock the zip file to find a txt file containing some weird codes.

8/1P4P1/1PP3P1/1P1P2P1/1P2P1P1/1P3PP1/1P4P1/8 w - - 0 1
8/1PPPPP2/1P6/1P6/1PPPPP2/1P6/1PPPPP2/8 w - - 0 1
8/1PPPPPP1/1PPPPPP1/3PP3/3PP3/3PP3/3PP3/8 w - - 0 1
8/1PPPPPP1/1P4P1/1P4P1/1P4P1/1P4P1/1PPPPPP1/8 w - - 0 1
8/1P4P1/1PP3P1/1P1P2P1/1P2P1P1/1P3PP1/1P4P1/8 w - - 0 1
5P2/3PP3/3P4/3P4/2PP4/3P4/3PP3/5P2 w - - 0 1
8/1PPPPPP1/1P6/1P6/1P6/1P6/1PPPPPP1/8 w - - 0 1
8/1P4P1/1P4P1/1PPPPPP1/1P4P1/1P4P1/1P4P1/8 w - - 0 1
8/1PPPPPP1/1P6/1P6/1PPPPPP1/1P6/1PPPPPP1/8 w - - 0 1
8/1PPPPPP1/1P6/1P6/1P6/1P6/1PPPPPP1/8 w - - 0 1
8/1P2P3/1P1P4/1PP5/1P1P4/1P2P3/1P3P2/8 w - - 0 1
8/8/8/8/8/8/1PPPPPP1/8 w - - 0 1
8/1P4P1/1PP2PP1/1P1PP1P1/1P1PP1P1/1P4P1/1P4P1/8 w - - 0 1
8/3PP3/2P2P2/1P4P1/1PPPPPP1/1P4P1/1P4P1/8 w - - 0 1
8/1PPPPPP1/1PPPPPP1/3PP3/3PP3/3PP3/3PP3/8 w - - 0 1
8/1PPPPP2/1P6/1P6/1PPPPP2/1P6/1PPPPP2/8 w - - 0 1
3P4/4PP2/5P2/5P2/5PP1/5P2/4PP2/3P4 w - - 0 1


I recognised this to be a kind of chess code to display board setups, and a quick Google search confirmed this. Every line represents a single chess board, with eight segments, separated by a ‘/’, each with 8 spaces. The spaces can be empty, represented by the numbers, or occupied by a piece, in which case there is a ‘P’.

If we create these boards, we find something peculiar… a flag!

NETON{CHECK_MATE}