Enabling SSH U2F authentication.
After some research online I've found a patch to the OpenSSH server that enables U2F authentication.
However there are 2 major caveats that would stop me from using this in a production environment:
- Security - the patch for OpenSSH has not yet been accepted/merged and currently works on an older version of OpenSSH
- Currently doesn't work on Mac OS, though maybe possible once Homebrew/legacy-homebrew#43676 is resolved