The VG Resource

hi, I am looking for help regarding how to extract .bfz file archives (changed to .pkn sometime around 2015/2016) used for the Korean game "Crazy Shooting Bubble Fighter" (크레이지슈팅 버블파이터). you can view the contents of .bfz files with a zip program of your choice (WinRAR, 7-Zip, etc) or by simply renaming it to .zip, but the .zip files are encrypted, and as far as I know, no one actually knows the passwords for them. 

linked below are some sample files so you can see where I'm getting at. no dedicated unpackers for these sorts of files exist because the game itself is a bit obscure even in its home country, so any help would be greatly appreciated.

https://files.catbox.moe/00oo21.bfz
https://files.catbox.moe/vnim29.bfz
https://files.catbox.moe/hyymbp.bfz (texture files for characters in the game)

1. Download and start GAME RIPPER
2. Press F2 key, and copy'n'paste the following bytes: E3 6A 7E 44 1E 92 97 51 6E 6E 5D BA
3. Drag'n'drop your .bfz file onto the window
4. Click on the "Decrypt / Unpack all" button
5. If you have more .bfz files, go to step 3.

Note: if you don't know the key then skip step 2, GAME RIPPER can crack ZIP encryption if there's at least one uncompressed PNG, WEBP, WAV or OGG in the archive (which is the case with your hyymbp.bfz file, the others seem to have .msh files only). This uses the Biham and Kocher attack running simultaneously on all CPU cores, so takes only a few minutes on a typical PC.

(10-09-2024, 02:24 PM)gameripper Wrote: [ -> ]1. Download and start GAME RIPPER
2. Press F2 key, and copy'n'paste the following bytes: E3 6A 7E 44 1E 92 97 51 6E 6E 5D BA
3. Drag'n'drop your .bfz file onto the window
4. Click on the "Decrypt / Unpack all" button
5. If you have more .bfz files, go to step 3.

Note: if you don't know the key then skip step 2, GAME RIPPER can crack ZIP encryption if there's at least one uncompressed PNG, WEBP, WAV or OGG in the archive (which is the case with your hyymbp.bfz file, the others seem to have .msh files only). This uses the Biham and Kocher attack running simultaneously on all CPU cores, so takes only a few minutes on a typical PC.

holy crap, wasn't expecting a reply this fast. The only gripe I have is that there doesn't seem to be an option to specify where the extracted files should be dumped, but otherwise your tool works wonders. 

only question I have is, does the above key only work for the hyymbp.bfz file? I tried dragging other .bfz files such as this one (og filename: ActionMessage) to the program and nothing loads, yet when I try dragging the file to the program first without entering the encryption key above it starts the key decryption process...but it takes awfully long since I'm using a low-spec laptop with a weak CPU. maybe someone with a better computer could try using the program.

edit: this is probably a dumb question but how can you tell if the archive contains an uncompressed PNG/WEBP/WAV/OGG/etc file in it? is it just a matter of guessing?

(10-18-2024, 02:56 PM)luxmaridia Wrote: [ -> ]holy crap, wasn't expecting a reply this fast. The only gripe I have is that there doesn't seem to be an option to specify where the extracted files should be dumped, but otherwise your tool works wonders.

You're welcome! Files are saved to the current working directory.

(10-18-2024, 02:56 PM)luxmaridia Wrote: [ -> ]only question I have is, does the above key only work for the hyymbp.bfz file?

No, it depends on the game. It is highly likely that all .bfz files for a specific game use the same password.

(10-18-2024, 02:56 PM)luxmaridia Wrote: [ -> ]I tried dragging other .bfz files such as this one (og filename: ActionMessage) to the program and nothing loads, yet when I try dragging the file to the program first without entering the encryption key above it starts the key decryption process...but it takes awfully long

Be patient! Start it before you go to sleep and it will surely find the key by the time you wake up!

The progress bar shows how long it would take to process all hash combinations. It exists as soon as a key is found, meaning 100% only reached if you're extremely unlucky and the very last hash candidate is the correct one. Also the progressbar isn't linear: if a group of hash values can be ruled out soon enough, then it will progress much faster.

(10-18-2024, 02:56 PM)luxmaridia Wrote: [ -> ]I'm using a low-spec laptop with a weak CPU.

On a low-spec laptop (assuming 1 CPU core running at 1GHz) in the worst case it should take no more than an hour tops.

(10-18-2024, 02:56 PM)luxmaridia Wrote: [ -> ]edit: this is probably a dumb question but how can you tell if the archive contains an uncompressed PNG/WEBP/WAV/OGG/etc file in it? is it just a matter of guessing?

Short answer: You don't need to know. GAME RIPPER autodetects this, and if key detection starts, then there is for sure (in case there isn't any, you'll see a "failed to retrieve encryption key, press F2 and specify manually" message).

Long answer: Nope, no guessing, if you want to know just list the archive with infozip or 7z, they will tell. The filename should end in PNG/WEBP/WAV/OGG/FBX/DAE/XML/EXE/etc. and method should be "Stored".

For your file for example:
FYI, the encryption key for this zip is: ED F6 45 3E 8C 8E 9F 95 49 FE 23 2B, took 00:27:18 to crack on my desktop PC (more than 5 years old, 1.4GHz).