I'm following a couple of links and haven't seem to found an answer to this question: Can I have my own server for private crates?
I was looking at couple of github issues and PRs. It looks like this is possible as this work has been merged etc...but I am confused as to how I set this up.
It's possible, my (stable) cargo outputs warning: unused manifest key: registries, so that may indeed be the case. I think your best bet is to simply try it out.