Not fully encrypted file [Shibuya Scramble wii]

Extraction and unpacking of game archives and compression, encryption, obfuscation, decoding of unknown files
RetroHelix
Posts: 23
Joined: Sat Aug 09, 2014 2:28 pm

Not fully encrypted file [Shibuya Scramble wii]

Post by RetroHelix »

EDIT: Looks like CriPakGUI, the tool I used to extract the cpks, is just doing something wrong here. I tried some other cpk extractors and the extracted files look ok.
Hi,

I was looking at the files of the game 428: Shibuya Scramble for the Wii. Most of the files are encrypted. But at the end of each file there is a part that is not encrypted. This part seem to be the first 256 bytes of the original file. See:
Image

At 0xC is a pointer (little endian) that points to the end of the encrypted file (0x01D0 + 0x10 (header size maybe) = 0x01E0). The orignial file is a TPL (image) with the identifier "00 20 AF 30".

Any idea how to decrypt this?
Last edited by RetroHelix on Tue Jan 09, 2018 4:45 pm, edited 2 times in total.
RetroHelix
Posts: 23
Joined: Sat Aug 09, 2014 2:28 pm

Re: Not fully encrypted file [Shibuya Scramble wii]

Post by RetroHelix »

Looks like the data is not encrypted but compressed... Luckily there are some uncompressed files on the disc and I was able to find an uncompressed and a compressed version of the same file. When I did a comtypescan with quickbms I got mostly garbage but there was one compressiontype which was able to extract at least a small part right. With comtype 629 COMP_LZW_STELLAR7 the string "DUMMY_LABEL" was extracted correctly:
Image

For the archiveformat:
long unk #always 0x0000
long unk #always 0x0000
SIZE long
ZSIZE long

Can anyone make sense of this?
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: Not fully encrypted file [Shibuya Scramble wii]

Post by aluigi »

Probably that "DUMMY_LABEL" comes from your memory, that's quite normal with wrong compression algorithms that read data outside their buffers.
RetroHelix
Posts: 23
Joined: Sat Aug 09, 2014 2:28 pm

Re: Not fully encrypted file [Shibuya Scramble wii]

Post by RetroHelix »

aluigi wrote:Probably that "DUMMY_LABEL" comes from your memory, that's quite normal with wrong compression algorithms that read data outside their buffers.

I see. Thanks for the information :)