[PC] Octogeddon .ayg file

Extraction and unpacking of game archives and compression, encryption, obfuscation, decoding of unknown files
kvn
Posts: 21
Joined: Sat Aug 29, 2015 11:43 pm

[PC] Octogeddon .ayg file

Post by kvn »

Hi there!
This is the only file in the game that has this extension, I'm sure it contains all the resources of the game
The size is big, hope you guys can help me to unpack this :D

http://www.mediafire.com/file/f3p19a6f77zmkka/data.ayg
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: [PC] Octogeddon .ayg file

Post by aluigi »

The files are xored with a 32bit key probably derived from the filename, but don't know what's the crc algorithm so files are extracted encrypted:
http://aluigi.org/bms/octogeddon.bms

If someone will provide the algorithm for calculating the key I will implement it in the script.
ash47
Posts: 3
Joined: Fri Mar 30, 2018 7:49 am

Re: [PC] Octogeddon .ayg file

Post by ash47 »

Hi guys,

I've written a tool which allows you to extract the Data.ayg, including fully decrypting all the files, you can then make changes to the files, and then repack the Data.ayg.

The encryption they used was rather trivial, not exactly sure how to explain it, but if you're still interested:

Link to the tool: https://github.com/ash47/OctogeddonHack ... ck-dataayg
Link to a tutorial explaining how to use it: https://youtu.be/F_AHkUhxUiU

The repo also contains tools to read and make changes to the save files. If you have any questions, feel free to ask :)
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: [PC] Octogeddon .ayg file

Post by aluigi »

Well done ash47, I have updated my script to version 0.1.1 :)
ash47
Posts: 3
Joined: Fri Mar 30, 2018 7:49 am

Re: [PC] Octogeddon .ayg file

Post by ash47 »

aluigi wrote:Well done ash47, I have updated my script to version 0.1.1 :)


I didn't test your new script, but your old script was a bit *SPAM* and didn't extract the folders correctly, and no idea if it can repack -- the script I put up allows you to create an entire archive from scratch, given a directory :)
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: [PC] Octogeddon .ayg file

Post by aluigi »

Right, path needed to be updated before calling the function recursively.
Fixed in 0.2
ash47
Posts: 3
Joined: Fri Mar 30, 2018 7:49 am

Re: [PC] Octogeddon .ayg file

Post by ash47 »

It's pretty cool that you do this, and I'm pretty impressed with quick BMS, tbh :O
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: [PC] Octogeddon .ayg file

Post by aluigi »

:D
SuperSocker
Posts: 1
Joined: Sun Jun 24, 2018 10:02 pm

Re: [PC] Octogeddon .ayg file

Post by SuperSocker »

I've noticed there's a number of what appear to be image files that end in .m5k. These can't be opened normally, and I've searched around the forums (and Google) and it seems this is the only game using this extension. Is there another way to crack these open?