Decompiling Objective-C Libraries

Question

I just finished the library in Objective-C, which I compiled as a static library for distribution.

I wanted to know what are the chances of getting this decompiled file.

• Do you know any software that can do this?
• If so, how can I protect me better?

EDIT: My static library is for iPhone / ARM

I created an algorithm that, depending on some parameters of the application, can work as demo or full code. You start the object using X variables and unlock the full version. I was wondering if they could see this algorithm so that they could create a key generator.

Answer 1

It is not clear what you are trying to protect yourself from. Yes, it could be reverse engineering. The simplest tool is otool , part of the standard developer distribution:

 otool -tV <library> 

From this, they come across things like IDA Pro , which supports the iPhone and is very good for this kind of work. Meanwhile, I am really surprised that I have not yet seen the otx refinement for iPhone / ARM. I would not be surprised if I see that in the end there will be a show. And, of course, gdb, if you are trying to figure out how everything happens and what data is at different points.

If you have more detailed information about what you are trying to protect yourself from, there may be some targeted answers. In addition, read Chuck.

Answer 2

If it is executed, it can be decompiled. Objective-C is especially easy to decompile into readable code due to its dynamic functions. If you want to make something a little more complicated, you can write most of your code in simple C and strip the executable - which, of course, has a trade-off that makes managing your application design difficult. But be honest with yourself: if someone wants to crack your code, you cannot stop them. Crackers have an almost unlimited amount of time and enthusiasm and will be really excited by any new efforts that you make to stop them. No one has developed copyrightable software yet, and the largest corporations in the world have tried. You will not do better than them, especially if you need to ask about it in Stack Overflow.

Spend the time spent decompiling and use it to make your product better - it will have much better profitability.

Answer 3

ChanceGetsDecompiled = ExpectedGainFromBeingDecompiled / PopularityOfLibrary

Well, if you REALLY want to know that I will try to decompile it myself. You do not say that it is for PPC, Intel or ARM, which matters. Here is the decompiler for the Intel i386 Decompiler

I don’t know what you could do (I don’t think there is much) to limit this. The code can always be the opposite. Be happy that you are not using java or .net. Their decompilation is so enjoyable.