Free (libre) SSHD for Android?

How can I install a **sshd** server (with **scp** support) on Android **without relying on Google Play Store** for my safety? Rooting the device or compiling the application is not a problem, but so far I'm unable to find proper instructions. I don't need a GUI either, some kind of on/off switch would be nice tho, but that's not required.