http://samdmarshall.com/re.html

Reverse Engineering Resources

Debugging

These are very important guides for understanding the debugging process and how applications work.

• Mac OS X Debugging Magic Technical Note (TN2124) (link - PDF Mirror)
• iOS Debugging Magic Technical Note (TN2239) (link - PDF Mirror)
• Understanding and Analyzing iOS Application Crash Reports (TN2151) (link - PDF Mirror)
• Malloc Debug Environment Variables (link - PDF Mirror)

Mach-O Binaries

Mac OS X and iOS use Mach-O file format for executable binaries and shared libraries. It supports multiple architectures in one binary file (Universal or fat binaries).

• Mach-O Wikipedia (link)
• OS X ABI Mach-O File Format Reference (link - PDF - PDF Mirror)
• Mach-O Programming Topics (link - PDF - PDF Mirror)

Analysis

Guides and introductory material to binary analysis.

• Analyzing Binaries with Hopper (link)

System ABIs

Calling conventions define how functions and subroutines receive the parameters passed to them from the calling function.

• ABI Wikipedia (link)
• Calling Conventions Wikipedia (link)
• Mac OS X ABI (link - PDF - PDF Mirror)
• iOS ABI (link - PDF - PDF Mirror)
• Dynamic Library Programming Topics (link - PDF - PDF Mirror) (Companion File - Companion File Mirror)
• OS X ABI Dynamic Loader Reference (link - PDF - PDF Mirror)

Language Resources

Language specific knowledge is often required to understand what is going on behind the scenes.

• Intel x86 Architecture (PDF - PDF Mirror)
• Introduction to x64 Assembly (PDF - PDF Mirror)
• ARM Architecture for ARMv7 (PDF Mirror)
• OS X Assembler Reference (link - PDF - PDF Mirror)
• Learn C The Hard Way (link)
• The C Library Reference Guide (link)
• Objective-C Language (link - PDF - PDF Mirror)
• Objective-C Runtime (link - PDF - PDF Mirror)

Further Reading

Collection of blogs and reading resources that give deep insight into how many aspects of languages and system functionality.

• NSBlog (link)
• Reverse Engineering Mac OS X (link)
• Landon‘s Blog (link)
• OS X Internals (link)
• Greg Parker‘s Blog (link)
• Ridiculous Fish (link)
• Snare‘s Blog (link)
• To The Apple‘s Core (link)
• The Objective-C Runtime: Understanding and Abusing (link)

Tools

Mach-O Binary Analyzers:

• MachOViewer (Homepage)

Hex Editors:

• Hex Fiend (Homepage)
• 0xED (Homepage)
• Synalyze It! (Homepage)

Disassemblers:

• Hopper (Homepage)
• IDA (Homepage)
• otool (man page)
• otx (Homepage)

Decompilers:

• Hopper (Homepage)
• Hex-Rays (Homepage)
• classdump (Homepage)
• codedump (i386) (Source ZIP)

Debuggers:

• GDB (Not shipped on OS X anymore) (Homepage)
• LLDB (Homepage - man page)
• PonyDebugger (link)

Memory Editors:

• Bit Slicer (Homepage - Source)

Various Command Line Tools:

• nm (man page)
• strings (man page)
• dsymutil (man page)
• install_name_tool (man page)
• ld (man page)
• lipo (man page)
• codesign (man page)
• hexdump (man page)
• dyld_shared_cache (link)
• vbindiff (link)
• binwalk (link)
• xpwntool (link)
• objdump (link)

Useful Source Repositories:

• Apple Source Code (link)
• PLCrashReporter (link)
• Mike Ash‘s Github (link)
• Landon Fuller‘s Github (link)
• Jonathan Rentzsch‘s Github (link)
• fG!‘s Github (link)
• openjailbreak (link)