Gears of War 3 XP and Trophys Checksum?
Hey guys.
I've found in the PlayerStorage.dat all values.
I think there is a kind of checksum in that file. If i change anything, it will always reset the stats.
I believe the checksum is 160 bit (20 Bytes) long and at the start of file.
Eventually it's SHA-1, RIPEMD or it's a variant checksum from epic. I don't know.
I've tried both checksum but without the knowen length it's a hopeless search.
It's possible to find the checksum in xex files or whatever. I don't know which options there are for.
Can somebody help me out or have a idea?
thanks in advance.
Re: Gears of War 3 XP and Trophys Checksum?
should it now show corrupt instead of reseting you? Reseting I believe usually means it didn't match up with a total value stored somewhere.
Re: Gears of War 3 XP and Trophys Checksum?
No, it's definitely a checksum.
I search in the GPD of the game and there is no matched value. The values are only in the PlayerStorage.dat.
I've saved 3 times with and the first 20 bytes changed. If i change anything the game ignore my modded save and create a new one.
For example my experience, i've changed it from 230 to 231, start the game and all stats are 0.
As i said, i think it's a SHA-1 or RIPEMD, but without the exact lenght hopeless.
Is there no other option?
Re: Gears of War 3 XP and Trophys Checksum?
Quote:
Originally Posted by
Philymaster
No, it's definitely a checksum.
I search in the GPD of the game and there is no matched value. The values are only in the PlayerStorage.dat.
I've saved 3 times with and the first 20 bytes changed. If i change anything the game ignore my modded save and create a new one.
For example my experience, i've changed it from 230 to 231, start the game and all stats are 0.
As i said, i think it's a SHA-1 or RIPEMD, but without the exact lenght hopeless.
Is there no other option?
Bruteforce it?
Re: Gears of War 3 XP and Trophys Checksum?
if you mod the multiplayer of GoW 3, you will get banned
Re: Gears of War 3 XP and Trophys Checksum?
Just to add,
It does use the GPD. and I think it has the same 20 bytes at the bigging of each setting.
dont think its a SHA1, but i think its more todo with the cryprion
Re: Gears of War 3 XP and Trophys Checksum?
@xxXENOPIRATExx:
Not exactly. You can earn xp and all medals in private matches (offline). So there is no problem.
I've now bruteforce all files with ALL checksums. But have no match.
So i guess it's a custom check by epic. Have anyone a other idea to discover the checksum?
I will try XOR and other things.
Re: Gears of War 3 XP and Trophys Checksum?
I've been looking into figuring this out myself. What I've found so far from the disassembly of the GoW3 default.xex is that it definitely implements/uses a standard-looking SHA-1 hashing algorithm at some point. So I'm 99% sure that's what it uses for the TitleSpecific and PlayerStorage.dat checksums. My guesses as to why it's different are that it either adds something onto the data before it hashes it, or it does some kind of transformation on the hash once it's calculated. Just speculating, though. I am not well versed in PPC assembly enough to understand everything that's going on :(
Constants used in the SHA-1 hashing algorithm are found at these offsets/subs (from disassembly in IDA):
.text:822E9018 sub_822E9018 (initial values - 0x67452301, etc.)
.text:822F9EB0 sub_822F9EB0 (values used in algorithm's main loop - 0x5A827999, etc.)
.text:822FB800 sub_822FB800 (initial values - branches to sub_822F9EB0 via sub_822FB590, probably the 'main' hash implementation)
.text:8231330C loc_8231330C (initial values)
.text:8297B5B8 (initial values)
.text:8297B5C8 (initial values)
.text:8297B70C (initial values)
.text:823FE558 sub_823FE558 looks like it could be processing the data to be stored, before it's hashed.
Anyone else want to take a crack at it?