Obj C and class-dump protection

Question

I understand that it is easy to hack Mach-O executable, I just want simple protection against \"class-dump\" tool. Is there any tool or XCode plugin that can change all classes

Answer 1

I wrote a bit about this in this blog post, but to summarise: you can avoid having methods appearing in class-dump by registering them at runtime, or just keeping them as functions.

If really all you want to do is rename the classes/methods, you can use the tops command-line tool or Xcode's refactoring feature.

Answer 2

Are you looking for Objective C obfuscators?

This page has a great discussion on Obfuscating Cocoa.

Answer 3

If you're not doing already, you can at least strip your executable of certain unnecessary symbols by enabling 'Deployment Postprocessing' and 'Strip Linked Product 'in the Xcode build setting. (Or just use the strip tool directly.) Better than nothing.

Answer 4

You really probably don't want to bother with this. Obfuscation will not prevent a determined hacker from reverse engineering a truly valuable algorithm. Casual users won't bother, so you're likely doing a lot of work for little added value. As @mvds points out in a comment to your question, NIB connections will betray the purpose of many classes and a determined hacker could use dtrace/Instruments.app to trace messages to uncover much of the rest of what they need.

Any truly valuable IP needs to be protected by something stronger than obfuscation and should probably be written in C/C++ as well as having legal patent and copyright protection (and enforcement).