Unpacking the Mach-O Mystery: A Deep Dive into Apple's Binary Format

This article delves into the intricacies of Mach-O, the binary format underpinning Apple's operating systems for executables, libraries, and object code. It meticulously dissects Mach-O's structure, encompassing the header, load commands, segments, and sections, alongside universal binaries. Furthermore, the article illuminates Mach-O's role in code signing integrity and Pointer Authentication Codes (PACs) on ARM64e systems. The mechanisms of code signing and PAC operation are explained in detail. Understanding Mach-O provides crucial insight into Apple's security measures and code execution processes.