Testing for Debugging Symbols
Overview¶
Static Analysis¶
To verify the existence of debug symbols you can use objdump from binutils or llvm-objdump to inspect all of the app binaries.
In the following snippet we run objdump over TargetApp (the iOS main app executable) to show the typical output of a binary containing debug symbols which are marked with the d (debug) flag. Check the objdump man page for information about various other symbol flag characters.
$ objdump --syms TargetApp
0000000100007dc8 l d *UND* -[ViewController handleSubmitButton:]
000000010000809c l d *UND* -[ViewController touchesBegan:withEvent:]
0000000100008158 l d *UND* -[ViewController viewDidLoad]
...
000000010000916c l d *UND* _disable_gdb
00000001000091d8 l d *UND* _detect_injected_dylds
00000001000092a4 l d *UND* _isDebugged
...
To prevent the inclusion of debug symbols, set Strip Debug Symbols During Copy to YES via the XCode project's build settings. Stripping debugging symbols will not only reduce the size of the binary but also increase the difficulty of reverse engineering.
Dynamic Analysis¶
Dynamic analysis is not applicable for finding debugging symbols.