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View Full Version : Finding The Checksum?



007sonic
01-22-2012, 02:35 AM
Ok so I read a lot of stuff that you guys posted about checksums but the only trouble I'm having right now is actually finding the checksum. Cause either I'm blind, or just too noob to find it. I've tried comparing multiple saves and I've figured out that the offset that I'm changing isn't encrypted cause it says what I'm trying to change in the right side of the hex editor (gvExperience) and I'm pretty sure it's a checksum cause I've tried to change my exp points multiple times but the game tells me the save is corrupted. I've checked to make sure I changed the correct value everytime and even tried to change the value just a little bit to make sure I wasn't going over a "cap" on exp points but no good, still said save was corrupted. So yea is there any specific way to find out the checksum in the hex editor cause I've found a MD5 checksum for the gamesave through an outside program called "Simple Checksum" but I haven't found the checksum in the hex editor.

007sonic
01-23-2012, 12:39 AM
Ok so I found a checksum button *facepalm* that will generate a checksum for the savegame

007sonic
01-23-2012, 01:03 AM
But I'm still not to sure what to do now that I have a checksum...

Vincent Valentine
01-23-2012, 01:20 AM
I believe you first have to figure out what type it is and switch it with a different checksum but have it still be the same type of checksum

If that didn't make to much sense then go to this link and scroll down to where it says something about checksums, basically in that thread it explains what I'm talking about

http://www.360haven.com/forums/showthread.php?1588-Introduction-to-Hexing-Programming-and-Game-Modding

007sonic
01-23-2012, 03:23 AM
Ok I think I found the checksum at the end of the data.dat file and it seems to me like its a MD5 checksum but for both the saves (modded, non-modded) they both have the same last four bytes "6B B1 3D 02" and on the right side of the hex editor it shows "k . - ." are they suppose to be different?

Vincent Valentine
01-23-2012, 04:41 PM
Did you ever figure it out yet?

pureIso
01-23-2012, 04:47 PM
Checksums always change. If the checksum file length is in the save, it never changes.

Noctis Caelum
01-23-2012, 04:51 PM
Ok so I read a lot of stuff that you guys posted about checksums but the only trouble I'm having right now is actually finding the checksum. Cause either I'm blind, or just too noob to find it. I've tried comparing multiple saves and I've figured out that the offset that I'm changing isn't encrypted cause it says what I'm trying to change in the right side of the hex editor (gvExperience) and I'm pretty sure it's a checksum cause I've tried to change my exp points multiple times but the game tells me the save is corrupted. I've checked to make sure I changed the correct value everytime and even tried to change the value just a little bit to make sure I wasn't going over a "cap" on exp points but no good, still said save was corrupted. So yea is there any specific way to find out the checksum in the hex editor cause I've found a MD5 checksum for the gamesave through an outside program called "Simple Checksum" but I haven't found the checksum in the hex editor.
I asked this question awhile ago and I dont understand them either...its goin to suck makin tools for newer games seein as most newer games has some type of security on them...

pureIso
01-23-2012, 04:52 PM
Even if you find it reversing it will be the super problem then ....you have to start learning ppc assembly hahaha

Vincent Valentine
01-23-2012, 04:57 PM
Even if you find it reversing it will be the super problem then ....you have to start learning ppc assembly hahaha
That's why we have Fairchild <3 lol

PUR3 RAF3X
01-23-2012, 05:20 PM
Yes the security are allways Shit lol

Ok I can aggre reversing are the best way but for this you need good skills.

You can start create 1,2,3 Saves with very short progress then you see if the Checksum etc change then you look which bytes change inside the data. And know have a Info where the security can start- end the calculation.Hex Workshop can calculate or use Algorithm Tool.
I have discover many Games with this way.

This work with Checksum32 very good ;)

pureIso
01-23-2012, 05:33 PM
When the new Algorithm Tool is released things should be a lot easier. ;)

Noctis Caelum
01-23-2012, 05:34 PM
That's why we have Fairchild <3 lol
true lol..also like the new name

Noctis Caelum
01-23-2012, 05:35 PM
When the new Algorithm Tool is released things should be a lot easier. ;)
i hope ur rite

007sonic
01-23-2012, 06:40 PM
Alright I'll start a couple more new games and see if those last 4 bytes change and if anyone else wants to help me figure out the checksum the game is Castlevania Lords of Shadow

Noctis Caelum
01-24-2012, 04:49 AM
Alright I'll start a couple more new games and see if those last 4 bytes change and if anyone else wants to help me figure out the checksum the game is Castlevania Lords of Shadow
damn thats crazy cause when i first learned to make SE thats one of the first games i wanted to do and heard it had a crazy checksum on it..so hope u figure this out and make a SE for it...i'll be waitin for ur editor lol...

Vincent Valentine
01-24-2012, 04:53 AM
Oh I herd it's like impossible to mod after you get around to almost the second disc but hey let's change that :P

Noctis Caelum
01-24-2012, 04:58 AM
Oh I herd it's like impossible to mod after you get around to almost the second disc but hey let's change that :P
He aims and shoots down plane good job ODD...A Hole lol.....o well on to the next lol

007sonic
01-24-2012, 05:40 AM
Oh I herd it's like impossible to mod after you get around to almost the second disc but hey let's change that :P
:humph: Is that why I seem to be having some trouble with this game >.< well time to learn some ppc

Vincent Valentine
01-24-2012, 05:51 AM
:humph: Is that why I seem to be having some trouble with this game >.< well time to learn some ppc
Yeah, the easiest way to find the money or whatever is mostly easiest to search for it when ur in the beginning of the game

007sonic
01-24-2012, 05:57 AM
Yeah, the easiest way to find the money or whatever is mostly easiest to search for it when ur in the beginning of the game
Oh no I've already found everything the only problem I have left to deal with is the checksum :x_x:

Vincent Valentine
01-24-2012, 06:01 AM
Oh no I've already found everything the only problem I have left to deal with is the checksum :x_x:
Oh well give xbox36Haz's checksum thingy he released and see if it helps and of u figure out how to use it... Make a video lol

007sonic
01-24-2012, 07:53 AM
Oh well give xbox36Haz's checksum thingy he released and see if it helps and of u figure out how to use it... Make a video lol
Oh cool a checksum thingy maybe that will fix it.

Vincent Valentine
01-24-2012, 08:19 AM
Hope it does help, of not wait tell Fairchild is done with his project to fix security for games and what not and see if that works then

Note: 666 post <3 the devil is coming to get me, by haven :,{

Noctis Caelum
01-25-2012, 08:02 PM
Hope it does help, of not wait tell Fairchild is done with his project to fix security for games and what not and see if that works then

Note: 666 post <3 the devil is coming to get me, by haven :,{
correction pureiso is working on something for that

007sonic
01-26-2012, 05:27 AM
correction pureiso is working on something for that
Yea i'm just going to wait for pureiso to finish that up and see how that goes cause I have no idea how to use XB36Hazards checksum finder

Noctis Caelum
01-26-2012, 05:39 AM
Yea i'm just going to wait for pureiso to finish that up and see how that goes cause I have no idea how to use XB36Hazards checksum finder
pretty much...pure is the man anyway