OpenSSH Server - anonymous account

Question

so I wanted to make a simple shell app for fun, via SSH. I made a custom shell using Python and the cmd module (that was pretty easy to make), added the shell in /etc/shells, made an account on my server (which login name is visitor), made the custom shell its default shell, and put a simple password (visitor), and it works pretty well.

But here's the deal: I want to remove the password step. I would like that when someone types in ssh [email protected], it goes straight through to the shell (autologin), without any previous step from the user, and I want this to only apply on the visitor account (not on any other existing account, even if a way to add more accounts like this would be cool (every account in a group?)).

Thanks in advance for any solution or answer! :)

Answer 1

I was answering similar question on Unix.SE. In short, I don't think there is possibility to do that without patching OpenSSH. But you can make sshd accept empty passwords:

   PasswordAuthentication yes
   PermitEmptyPasswords yes

Also you need to modify PAM to accept empty passwords by changing nullok_secure to nullok in /etc/pam.d/common-auth.

There is also none authentication, which sshtron is based on, but it is supposed to fail by the RFC4252.

debug1: Authentication succeeded (none).

To achieve the same behaviour, you would need to patch openssh server, or create a server using something different.