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Old 23 September 2012, 18:08   #1
MethodGit
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Battle Chess - obscure on-disk protection?

Been playing with both IPF sets of Battle Chess 1 just now, and I strongly suspect that there's hidden checksum protection that's executed during initial boot-up.

Been wanting to test out a couple of cracks for the game, but as it appears, any modification whatsoever to the "BattleChess" file - heck, even if you just open the file in a hex editor and save it with no changes made - causes this to pop up before one even sees the CLI window:



This, of course, does not happen on a straight ADF copy with no modifications. I checked the bootblock and there's nothing different about it, just the standard dos.library bootblock seen in many other disks. So where the heck is it suddenly performing this random routine that I presume corrupts the stack in some way?


On a related note, there appears to be a bug in regards to the way BC's Workbench environment attempts to write changes to the disk after opening the disk contents window. (Now this is another matter I'm interested in having explained to me first: why - with most WB1.3 based games - does the disk suddenly write stuff to itself after finishing examining the contents of a disk in a WB window, and why does it only ever happen under a WB1.3 environment?) The moment it tries to write anything, you get this:



This never happens on a write-protected disk. Poor programming, mayhaps?
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Old 23 September 2012, 18:42   #2
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Why don't you just give up?
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Old 23 September 2012, 18:54   #3
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I don't know why I even bother to reply but IIRC BattleChess uses "hidden" files and uses trackdisk to load the data. Which means you're corrupting the data when you write to the disk. Looks like another very simple protection you didn't understand.
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Old 23 September 2012, 20:58   #4
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I don't know why I even bother to reply but IIRC BattleChess uses "hidden" files and uses trackdisk to load the data. Which means you're corrupting the data when you write to the disk. Looks like another very simple protection you didn't understand.
I was already aware that the game used data not visible in the filesystem. However, you made a good point there - by altering visible files on the disk, I probably did end up overwriting crucial data on the disk without realising.

And this may be 'simple' to you and the rest, but it's all new to me! Can't I be allowed to learn?
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Old 23 September 2012, 21:19   #5
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I was already aware that the game used data not visible in the filesystem.
Why did you try to write to the disk then? And why did you open the thread here if you know all that already (as usual)?

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And this may be 'simple' to you and the rest, but it's all new to me! Can't I be allowed to learn?
This is VERY simple stuff and seeing that you know everything (just see your very own reply to me) but STILL open threads asking for help, what do you expect? Anyway, I knew I should not have bothered to reply and next time I won't!
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Old 23 September 2012, 21:26   #6
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Why did you try to write to the disk then? And why did you open the thread here if you know all that already (as usual)?
I thought that by altering just one file only slightly and not try to copy over it or move stuff about, that none of the trackdisk data would be affected. Now I've learnt how wrong I was!

Seriously, why do you automatically assume that just because I knew one specific minor thing beforehand, that I'm completely knowledgeable about the rest of the game and its protection? As the saying goes, "Poor Communication Kills", and it's this sort of confusion that is causing so much aggro and for me to be stressed out by people bitching at me again about why I'm asking this or why I'm trying to crack this game. I go here to learn, only to be told "you know EVERYTHING about this game or this protection" even when I don't. Marvellous.
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Old 23 September 2012, 22:20   #7
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I could say a lot to your very "interesting" nonsense but I will just repeat myself: I won't bother to reply anymore. Had you known anything about this game you would not have needed to open a thread and then, when you get answers, as usual pretend you knew it all anyway. Indeed, marvellous! And the only one I see "bitching" here is you, no one else. Anyway, you don't need any help from anyone since it is ALWAYS the same, it's ALWAYS the fault of the others. And now I'm outta here, should really not have spent any single second replying to you.
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Old 23 September 2012, 22:22   #8
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I thought that by altering just one file only slightly and not try to copy over it or move stuff about, that none of the trackdisk data would be affected. Now I've learnt how wrong I was!
You must be very careful when altering files on any disk you wish to investigate.

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Been wanting to test out a couple of cracks for the game, but as it appears, any modification whatsoever to the "BattleChess" file - heck, even if you just open the file in a hex editor and save it with no changes made - causes this to pop up before one even sees the CLI window...
When you edit a file and save it back to disk - even with no changes made - threre is no guarantee that the new file will overwrite the disk blocks used by the old, and if there are any files hidden in 'loose' blocks which are invisible to Workbench, then they may be in danger of being overwritten.

To avoid this, use a disk sector editor to make your changes and recalculate checksums, before writing back to disk.
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Old 23 September 2012, 22:36   #9
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You must be very careful when altering files on any disk you wish to investigate.

When you edit a file and save it back to disk - even with no changes made - threre is no guarantee that the new file will overwrite the disk blocks used by the old, and if there are any files hidden in 'loose' blocks which are invisible to Workbench, then they may be in danger of being overwritten.
Aaaaaaaah, okay! Will keep that in mind in future.

Quote:
To avoid this, use a disk sector editor to make your changes and recalculate checksums, before writing back to disk.
Which editor would you personally recommend? Do any of them allow to search for specific values so that one doesn't need to spend time guessing which sector they have to be on to find the bit they wish to edit?
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Old 23 September 2012, 22:48   #10
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Which editor would you personally recommend? Do any of them allow to search for specific values so that one doesn't need to spend time guessing which sector they have to be on to find the bit they wish to edit?
http://aminet.net/search?query=DiskMonTools

Yes, this one has the search facility (both ASCII and Hex).
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Old 24 September 2012, 00:53   #11
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Theres a far easier to way to crack this particular game, and Interplay even provide you with the very tool to help you
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Old 24 September 2012, 01:42   #12
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I know absolutely next to nothing about cracking, so I do apologise if this is a bit of a naive comment to make, but one of the things I noticed in the screenshots was that there was a hard disk installer there. Have you tried installing it to a HD and working on it from there?

Edit: Just used the hard drive installer to "install" to 'ram:' by assigning 'dhx:' to 'ram:', upon installation it reveals two files named 'ChessStuff' and 'ChessSaves'. I assume that these are the hidden files on the disk that the custom file loader uses. The reasoning/my hunch behind this is I had a feeling a custom floppy loader couldn't be used upon installation to a HD, so anything hidden had to be 'extracted' to regular files.

I don't know if this was what Galahad was referring to, but I can't see anything else on the disk (if it was what he was referring to, then YAY, I suppose!)... I just saw StingRay mention 'hidden files' and 'trackloader', and saw there was a HD installer and thought it may have been worth a go.

Last edited by Sektor 83; 24 September 2012 at 02:07. Reason: Things and bits and stuff.
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Old 24 September 2012, 02:39   #13
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I know absolutely next to nothing about cracking, so I do apologise if this is a bit of a naive comment to make, but one of the things I noticed in the screenshots was that there was a hard disk installer there. Have you tried installing it to a HD and working on it from there?

Edit: Just used the hard drive installer to "install" to 'ram:' by assigning 'dhx:' to 'ram:', upon installation it reveals two files named 'ChessStuff' and 'ChessSaves'. I assume that these are the hidden files on the disk that the custom file loader uses. The reasoning/my hunch behind this is I had a feeling a custom floppy loader couldn't be used upon installation to a HD, so anything hidden had to be 'extracted' to regular files.

I don't know if this was what Galahad was referring to, but I can't see anything else on the disk (if it was what he was referring to, then YAY, I suppose!)... I just saw StingRay mention 'hidden files' and 'trackloader', and saw there was a HD installer and thought it may have been worth a go.
Big ups to the chap that doesn't know about cracking, but has single handedly done something that Methodgit should have considered.

Yes my friend, by using the supplied hard drive installer, in the exact way you suggested, means you can then extract all the relevant information.

The bonus is, you can then stick all of the installed files back onto an AmigaDOS disk, and then crack to your hearts content from there, knowing that the game will work from floppy, and can still be copied to hard drive.

It is of course still completely possible to crack it in the same layout that it comes on the original disk, but thats what cracking is all about, is finding a way around the difficulties set by the programmer.
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Old 24 September 2012, 03:47   #14
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Ah, thanks man Although admittedly, I wouldn't have known there were hidden files/a trackloader there to begin with unless StingRay had said so (or I'd looked at the code, which I didn't, and I very much consider myself a beginner at assembly language anyway :/). I can't help but feel that Interplay shot themselves in the foot a little with that, though!??

Last edited by Sektor 83; 24 September 2012 at 03:50. Reason: ...
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Old 24 September 2012, 09:42   #15
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I can't help but feel that Interplay shot themselves in the foot a little with that, though!??
Possibly, but how many of us had Hard Drives back in '86?
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Old 24 September 2012, 14:17   #16
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On a related note, there appears to be a bug in regards to the way BC's Workbench environment attempts to write changes to the disk after opening the disk contents window. (Now this is another matter I'm interested in having explained to me first: why - with most WB1.3 based games - does the disk suddenly write stuff to itself after finishing examining the contents of a disk in a WB window, and why does it only ever happen under a WB1.3 environment?)
Under Workbench 1.x (at least versions 1.2 and 1.3), whenever you open a drawer or disk icon Workbench writes a file named ".info" to that directory. I'm not sure exactly why it does that (does anyone know?), but it's quite annoying. Because, if you want to preserve the contents of your original game disks, never boot with the disk write-enabled, or insert the disk write-enabled after booting Workbench 1.x. As soon as you click the disk's icon, Workbench writes to the disk.

I don't know why you got a crash when WB tries to write to the Battle Chess disk. It would be interesting to see whether you get the same crash after booting an unmodified Workbench 1.3 disk, then inserting Battle Chess and opening its disk icon.
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Old 24 September 2012, 15:44   #17
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Probably the most pointless thread over eab in past few months
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Old 24 September 2012, 15:48   #18
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Don't forget such pearls like http://eab.abime.net/showthread.php?t=65562 But this is a good candidate indeed
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Old 24 September 2012, 16:04   #19
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You know, I don't appreciate having threads where I had genuine problems understanding an error in a game be called "pointless".

I thought this community knew better than to be so snobbish.
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Old 24 September 2012, 16:46   #20
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Its not snobbish i'm pretty sure when you started this venture of yours everyone was willing to help you but the lack of humility and big headedness from yourself has what has turned people against you. People in general like helpibg people who are grateful and take on advice and criticism in the manner it is intended (ie to make you think about what you are doing and maybe ways you can improve yourself)

People certainly do not like helping people that want you to do everything for them.

You are trying to learn which is commendable but it is not the likes of stingray and galqhads job to teach you. Get stuck in ruin a few things learn from your mistakes yourself. Thats how they did it. an

And as a teacher i can asure you something discovered by yourself is far more rewarding than someone spoon feeding you the info and it also makes it easier to remember.
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