FluxArchiv (Part 2) (Category: Reversing) Author(s): sqall
These sneaky humans! They do not just use one passcode, but two to enter the
Festzelt. We heard that the passcode is hidden inside the archive file. It
seems that the FluxFingers overrated their programming skill and had a major
logical flaw in the archive file structure. Some of the drunken Oktoberfest
humans found it and abused this flaw in order to transfer hidden messages.
Find this passcode so we can finally drink their beer!

(only solvable when FluxArchiv (Part 1) was solved)
Here is the challenge:
https://ctf.fluxfingers.net/static/downloads/fluxarchiv/hacklu2013_archiv_challenge1.tar.gz