Apple Cache
This is a reverse engineering attempt of the Apple Content Caching system.
Currently the locator service is implemented, but I am in the process of writing documentation on how the cache registration and server work.
The goal of this project is to challenge myself in a serious reverse engineering attempt while also creating something I want to make: an Apple Content Cache that works on Linux servers.
Content Caching
Content Caching is available in the Sharing section of System Preferences.
It is used to cache content on your local network for public Apple content or
iCloud content. The /usr/libexec/AssetCache/AssetCache is responsible for a majority
of the work. It has an HTTP server that has an API that allows fetching and uploading of content from the server.
Research
Methodology
The work here was done by using Charles Proxy and Frida.
The tools/frida-ssl-pin.js file is a Frida script that can attach to any macOS process and disable all SSL verification and SSL certificate pinning. This has allowed me to deeply examine the requests going to Apple's servers. This script is likely useful
for many other use cases. If anyone else uses it, I'd love to hear about how it was used (I'm a super huge nerd and am quite interested in reverse engineering).