Lab: Parse a universal Mach-O wrapper

Apple's fat.h defines a wrapper with a fat_header followed by architecture records.

For the classic 32-bit fat_arch form, each architecture record includes:

• CPU type;
• CPU subtype;
• file offset;
• slice size;
• alignment as a power of two.

The classic wrapper structures are stored big-endian.

Build the parser

Write a Python program that:

1. recognizes FAT_MAGIC and swapped representations;
2. reads the architecture count;
3. validates that the architecture table fits in the file;
4. parses every architecture record;
5. validates that each slice offset and size remain inside the file;
6. reports architecture identity, offset, size, and alignment;
7. reads the first four bytes of each slice and reports whether it appears to contain a Mach-O image.

Do not assume slices are adjacent. Use their explicit offsets.

Deliverable

Produce:

• fat_parser.py;
• a JSON architecture map;
• SHA-256 of the tested file;
• one paragraph explaining the wrapper's byte order;
• one paragraph explaining why an offset table is different from “just concatenating binaries.”

Cross-check with lipo -info on macOS if available, or with an independent library such as LIEF on another platform.