SolutionThe challenge is about steganography. Given the GIF file, there are two ways the flag could be encoded there: images or the game itself.
It turns out it is possible to encode data in a chess game. Google gives this as a first result: https://incoherency.co.uk/chess-steg/index.html
Also a CLI version: https://github.com/Alheimsins/chess-steg-cli
So, we need to get a PGN representation of the game. We could do this in at least 2 ways:
1. Convert all moves to PGN format by hand.
2. Write a program which splits the GIF into frames, analyzes frames and outputs game in PGN format.
We go with 2nd approach since it's smarter and more reliable.
We implement a simple chess OCR, and get the output for our game. First part of the solution: [solution1.py](https://github.com/oioki/balccon2k20-ctf/blob/master/misc/noob-game/solution/solution1.py)
    ./solution1.py > game1.txt
See [game1.txt](https://github.com/oioki/balccon2k20-ctf/blob/master/misc/noob-game/solution/game1.txt)
We can try to import to lichess.org, and it completes successfully. However, current representation is not complete -- marks for capturing pieces and checks are missing. But after exporting from lichess.org it is fixed. See [game2.txt](https://github.com/oioki/balccon2k20-ctf/blob/master/misc/noob-game/solution/game2.txt)
Now we can try to decode this game with chess-steg-cli. If we try to decode the whole game, the tool shows the error Illegal move played??. This could happen if we have more moves than enough to encode the message. We will try to reduce number of moves in the party and get the flag in a game with 101 moves. See [solution2.py](https://github.com/oioki/balccon2k20-ctf/blob/master/misc/noob-game/solution/solution2.py) and its [output](https://github.com/oioki/balccon2k20-ctf/blob/master/misc/noob-game/solution/solution2.output)