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View Full Version : How to spoof a hash check?



Rakeris
05-25-2008, 02:45 PM
Well, might as well tell the whole story.

I recently got Age of Conan, and at the start of the game there are a number of intro screens. I find them rather annoying and would like to remove them. But the problem is the launcher checks for certain files, if they are not there they get redownloaded. It also does a hash check on them.

So is there anyway to spoof a hash check, on some random file so I can replace the rather large in size videos with them.

Thanks!

pifpaf
05-25-2008, 09:19 PM
as far as I know it is not possible to skip intro movies, there is no in-game setup for that and you cant delete the movies files.

mbucari1
05-26-2008, 07:44 AM
you try putting empty files in their place instead of deleting them?

Sometimes the game has to read the metadata of the file in order to run (in the case of Rainbow six vegas 2).

Rakeris
05-26-2008, 01:58 PM
Yes I have tried that, hence why I am asking how to spoof a hash check. I tried editing the move files down to .01 second. But it scans and then redownloads them, even with the exact same name. So I assume it is doing some sort of hash check.

mbucari1
05-26-2008, 05:51 PM
Yes I have tried that, hence why I am asking how to spoof a hash check. I tried editing the move files down to .01 second. But it scans and then redownloads them, even with the exact same name. So I assume it is doing some sort of hash check.
my guess is a size check combined with a file format check (or maybe just one of the two) Try creating a file with the same number of bytes as the movie files. It probably won't work, but you can give it a try.

But if it is a hash check, there is no spoffing it. You'd have to hack the game and enter your own hash.

jayz707
05-26-2008, 06:08 PM
you will prolly have to mess with the game code....

or try and modify its memory... contents...(ex where it keeps the hash...)

lynx
05-29-2008, 05:00 PM
It's unusual for things like this to be hard coded into the application, it's just too much work to change a simple intro file.

More probably there's a config file which contains the name of the intro files (and probably all the other files too). If so, you might find that it also contains the size of the file, and possibly even a hash check.

If that's the case, and it is a plain text file, you can simply edit the file. Of course, if it contains a hash check then your next problem is knowing how they calculate that hash checksum.

Snee
05-29-2008, 07:30 PM
Looks like like you are on the right track wrt shutting them off, assuming this still works:
pkbO5-6CpZY

Additional instructions. (http://conanq.com/viewtopic.php?f=3&t=23)


Start AoC using AgeOfConan.exe (located in your AoC Directory) after deleting the files...

Another (probably better) method:
Alternatively you could just rename the "Movies" folder to something like "Movies-zzz" and then when you wanted to run AoC using the ConanPacher.exe you could switch the filename back to "Movies"...

Basically, like it says there, the best current method might just be to get in the habit of starting it from the game .exe rather than the patcher, and just run the patcher when it's really needed.

I have had a similar setup with other games, with two different versions of the shortcut, one for updating and one for playing.

It's also possible that there's a config or .ini you can change, might even be an option to set "show movies" or something to 0, but given it's the company logos, they won't be wanting people to do it, so don't count on finding any such option easily.

As for spoofing hashes, I was thinking of doing that with md5s, once upon a time. The idea was to create something you input a hash string into, and get a string back that'd become the same hash when run through md5, like. Never sorted out the problems with it, but I imagine someone could write something similar that generated files, possibly, which could trick md5-checks, anyways. It was all pretty sketchy, though.

Rakeris
05-30-2008, 05:45 PM
Sadly that doesn't work anymore. It seem it was changed so the .exe now links to the patcher as well. As launching the .exe launches the patcher right after. =\

tesco
05-30-2008, 11:20 PM
Looks like like you are on the right track wrt shutting them off, assuming this still works:
pkbO5-6CpZY

Additional instructions. (http://conanq.com/viewtopic.php?f=3&t=23)


Start AoC using AgeOfConan.exe (located in your AoC Directory) after deleting the files...

Another (probably better) method:
Alternatively you could just rename the "Movies" folder to something like "Movies-zzz" and then when you wanted to run AoC using the ConanPacher.exe you could switch the filename back to "Movies"...Basically, like it says there, the best current method might just be to get in the habit of starting it from the game .exe rather than the patcher, and just run the patcher when it's really needed.

I have had a similar setup with other games, with two different versions of the shortcut, one for updating and one for playing.

It's also possible that there's a config or .ini you can change, might even be an option to set "show movies" or something to 0, but given it's the company logos, they won't be wanting people to do it, so don't count on finding any such option easily.

As for spoofing hashes, I was thinking of doing that with md5s, once upon a time. The idea was to create something you input a hash string into, and get a string back that'd become the same hash when run through md5, like. Never sorted out the problems with it, but I imagine someone could write something similar that generated files, possibly, which could trick md5-checks, anyways. It was all pretty sketchy, though.How did you do that?
You can't reverse MD5s. :unsure:

lynx
05-31-2008, 01:17 AM
Looks like like you are on the right track wrt shutting them off, assuming this still works:
pkbO5-6CpZY

Additional instructions. (http://conanq.com/viewtopic.php?f=3&t=23)

Basically, like it says there, the best current method might just be to get in the habit of starting it from the game .exe rather than the patcher, and just run the patcher when it's really needed.

I have had a similar setup with other games, with two different versions of the shortcut, one for updating and one for playing.

It's also possible that there's a config or .ini you can change, might even be an option to set "show movies" or something to 0, but given it's the company logos, they won't be wanting people to do it, so don't count on finding any such option easily.

As for spoofing hashes, I was thinking of doing that with md5s, once upon a time. The idea was to create something you input a hash string into, and get a string back that'd become the same hash when run through md5, like. Never sorted out the problems with it, but I imagine someone could write something similar that generated files, possibly, which could trick md5-checks, anyways. It was all pretty sketchy, though.How did you do that?
You can't reverse MD5s. :unsure:
Although you can't reverse MD5s, the calculation to work them out is pretty simple. As long as you know the calculation (and by definition that is publicly available) it is reasonably easy to create another file that has the same checksum. Even brute force can do it in a short period of time for a small file. Of course, this assumes that the file length is unimportant, that can be the killer for this sort of hack.