[peteradio]

That is very cool, how is this accomplished??

[humblebee]

Enable empty password for a particular user, and set the default login shell to the registration program.

[0]https://github.com/jackdoe/baxx/blob/3d2f6f014e5def3b5c35496...

[1]https://github.com/jackdoe/baxx/blob/3d2f6f014e5def3b5c35496...

[cat199]

not author, but you can force login commands for users in ssh configuration, so make this your script and away you go