I use SSH every day. I login to remote machines, push code changes to github and scp files. Like many programmers, I know how to use SSH to get things done but had never looked deeper to understand the protocol itself.

I recently wrote a minimal SSH client to help demystify the protocol. In this post, I'll explain some of the core concepts to help anyone else doing the same. This will be a 10,000ft overview with references to some interesting parts - not an implementation guide.