Protecting Source Code

[AwesomeHighFive]

I was just told that UnrealScript source code cannot be protected when publishing a title through the UDK. Is this true, and is there a way to circumvent that issue?

Even if you're just releasing a free mod, it seems like you wouldn't necessarily want your code exposed for the world to see, at least, not all of it.

[MonsOlympus]

Do you have any UnrealScript source code worth protecting?

[ankangronto]

Where did you read this?

[Graylord]

The source code is not available when packaged. Simple as that.

[rogacz]

More like 'the source code is available when packaged in a compiled form'. Which does not exactly mean safe, depending on how well it can be decompiled. Been wondering this myself, whether you can obfuscate or do some other similar stuff to it.

[Unearthly]

Write your code in C++ with DLLBind.

[BlackOps]

The Hunted a mod for UT3 had somehow protected unreal script you could only see default properties after Exporting though i have no idea how to do this.

[Crusha K. Rool]

Every compiled .u file contains the whole source code in uncompiled form at the end of the file (actually the majority of the file is the readable source code, you can check it yourself with a simple text editor).
I don't know if UDK gets rid of that stuff during the cooking process, but if not then you can already slightly increase the safety by deleting the end of the files manually.

[MVGS]

I doubt you could do that. Even from AAA games using UE3 one can extract UnrealScript code.

[Iron_Maniac]

Every compiled .u file contains the whole source code in uncompiled form at the end of the file (actually the majority of the file is the readable source code, you can check it yourself with a simple text editor).

I thought that was a closely guarded secret. You've let the cat outta the bag now.

Seriously though UDK Frontend (link below) has a strip source function (number 4 in the link). I haven't tried it but it may be exactly what you're looking for.

http://forums.epicgames.com/showthread.php?t=741905

Also please stop putting those pics in your posts. They may be briefly amusing to look at but its kinda hard to you seriously with them there.

[Graylord]

More like 'the source code is available when packaged in a compiled form'. Which does not exactly mean safe, depending on how well it can be decompiled. Been wondering this myself, whether you can obfuscate or do some other similar stuff to it.

Source code = / Packaged code.

[rogacz]

Meh so the most you can do is obfuscate which will not be so useful since you want to reuse as much of udk code as possible anyway.

[Graylord]

I doubt you could do that. Even from AAA games using UE3 one can extract UnrealScript code.

You sure about that? How would that be done? The engine doesn't actually run UScript, it runs the compiled form, so it is never "exctracted" in the process.

[Blade[UG]]

theoretically the bytecodes could be decompiled, but i don't actually know of any programs that can do that. You can stripsource on the .u packages, and the cooked packages don't actually have the script in them aside for tiny bits, from what i've seen.

[meowcat]

UT Package Tool appears to decompile the bytecode on select Unreal Engine games. That's how you can look at the SplinterCell or Raven Shield source code for instance (though the results tend to be pretty mangled with most(all) native functions given their number identifier instead of the original name).

[Solid Snake]

It's really not worth protecting. The best way to protect your code, is with a lawyer.

[UnrealEverything]

decompiling works like this with a batch file:

"C:\Program Files\Unreal Tournament 3\Binaries\UT3.exe" batchexport %1 class .uc "C:\Users\XYZ\Documents\My Games\Unreal Tournament 3\UTGame\Decompiled\%~n1\Classes\"

XYZ is your users name ofcourse

You just feed it a .u file and it does the rest for you
I dont know if it would work with UDK though, edit the paths in the batch to UDK/your liking and try it I guess...


Also Planetstorm mod for UT3 had the same protetction in their scriptfiles.

[Blade[UG]]

batchexport doesn't work on cooked script files.

[Wormbo]

And BatchExport doesn't decompile, but only export. The script, as mentioned before, is imported as raw text, excluding class defaultproperties. What BatchExport does is exporting the imported script text and generate a defaultproperties block from the class defaults.

[280Z28]

theoretically the bytecodes could be decompiled, but i don't actually know of any programs that can do that. You can stripsource on the .u packages, and the cooked packages don't actually have the script in them aside for tiny bits, from what i've seen.

It's not just theoretical - I wrote a tool that does exactly that. The script compiler doesn't optimize the scripts, so the decompiled bytecode differs from the source only in a few trivial ways. All you need is the names of the numbered native of functions labeled as native(##), which in the case of UDK is easy since they're publicly available and you can't add new ones.

[MonsOlympus]

It's really not worth protecting. The best way to protect your code, is with a lawyer.

I have to roll with this too. I very much doubt the OP has source they want to protect to this extent. The best form of protection is to not release it!

[toxicFork]

Hey guys I made this game, it's so awesome that I'm not gonna release it because other people will try to clone it.

[Solid Snake]

I have to roll with this too. I very much doubt the OP has source they want to protect to this extent. The best form of protection is to not release it!

Just to further clarify what I meant, is that you can put in X amount of dollars and time to "protect" your code, but given that this is UDK, someone can create a tool which can decompile all UDK games thus your "protection" method ends up costing you money. Thus, instead of spending X amount of dollars and time for a "potential" threat, spend it when it actually occurs.

[Wormbo]

And when it happens, take advantage of the community and make the copyright infringement public. If it causes you actual loss of money, you can still take it to court. But being publicly known as code stealer certainly hurts as well.

[toxicFork]

If a game which is made by stealing your code is more popular than yours, you did something wrong somewhere.