Reverse Engineering iMessage: Leveraging the Hardware to Protect the Software
iMessage is a widely used secure messaging app and protocol across the Apple ecosystem. Curious about what it would be like to run iMessage on other platforms, we took a reverse engineering approach to understand how iMessage operates and examine possibilities to extend it to other platforms.
The goal of this article is to show how Apple leverages the fact that it produces the hardware to protect its software. To explore this, we will try to connect via Apple Push Notification (APN) directly on the network level, and see what challenges we face. Along the way, we’ll reverse engineer small parts of the apsd daemon on macOS and the APN protocol itself using popular open-source tools.
