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PostPosted: Wed Nov 24, 2021 10:30 am 

Joined: Mon Nov 22, 2021 12:13 am
Posts: 2
So I've been on a long journey to decrypt a mobile game, Mass for the Dead, right? I'm no coding expert by any means, but I've been doing what I can to try and make progress.

Essentially, what I want to do is take the "overlord" script from this thread: viewtopic.php?f=9&t=15671&hilit=mass+for+the+dead (I've already modified it to try more XOR key combinations because the original only decrypts a handful (I'll attach the original work in this post)--

Code:
# Set up a list of possible xor keys

PutArray 0 0 "\x00\xff\xff\xff\x00\x00\x00\x00"
PutArray 0 1 "\x00\xff\xff\xff\xff\x00\x00\x00\x00\x00"
PutArray 0 2 "\x00\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00"
PutArray 0 3 "\x00\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00"
PutArray 0 4 "\x00\xff\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00"
PutArray 0 5 "\x00\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00"
PutArray 0 6 "\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
PutArray 0 7 "\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
PutArray 0 8 "\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
PutArray 0 9 "\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"


Get SIZE asize
Get TEMPNAME basename
String FILENAME P "%TEMPNAME%_dec"

For A = 0 To 9
   GetArray KEY 0 A

   FileXor KEY 0
   Goto 0
   GetDString TEXT1 7
   Goto 0x0c
   GetDString TEXT2 5
   Goto 0x12
   GetDString TEXT3 4

   String TEMP1 P "%TEXT1% %TEXT2% %TEXT3%"

   If TEMP1 = "UnityFS 5.x.x 2017"
      Log FILENAME 0 SIZE
      Exit
   Endif

Next A



--and extend it in a way that it will try more XOR keys to decrypt files. I want to go beyond 5 keys (I added “PutArray”’s 6-9), but I keep breaking the script in the process trying to adapt the rest. There’s also a disconnect between what I’ve added and the rest of the script, so it’s hardly better than the original.

It's probably something somewhat simple, but having some direction to decipher the logic would be nice.

If anyone wants to try any specific sample files to decrypt, I'll post a link to a thread that has most, if not all the files for the game: https://forum.xentax.com/viewtopic.php?f=16&t=24400 (I'm specifically looking at the files in the "u" folder if you want to look at it.) I would attach the files more directly here, but it seems the forum doesn't support the file type.


Attachments:
File comment: From here on zenhax (https://zenhax.com/viewtopic.php?f=9&t=15671&hilit=mass+for+the+dead)
overlord.txt [818 Bytes]
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