RayCity .JMD Files

Extraction and unpacking of game archives and compression, encryption, obfuscation, decoding of unknown files
luke3107
Posts: 2
Joined: Tue May 15, 2018 10:00 pm

RayCity .JMD Files

Post by luke3107 »

Hey Guys,

i wanted to ask if anyone has a script to unpack .JMD Files. I would be very thankful.

I attached the file as example.

Regards, Luke3107
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: RayCity .JMD Files

Post by aluigi »

There is an unicode magic: "J2m Data Format 1.0"
The data looks partially obfuscated, for example from offset 0x80 till 0x2ae0 and some other subsequent blocks.
It's strange the presence of "IEND" without the "PNG" header which means the file is partially encrypted.
All the DDS files are in clear text so you can dump them with a file ripper.
luke3107
Posts: 2
Joined: Tue May 15, 2018 10:00 pm

Re: RayCity .JMD Files

Post by luke3107 »

Thanks for the fast answer and i got the .DDS Files. but there are also 3D Models inside, can u somehow extract them even when its encrypted?

Regrads, Luke
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: RayCity .JMD Files

Post by aluigi »

no, I didn't see a way to guess/crack the obfuscation. It's necessary reverse engineering but I don't know if someone is interested in doing it.