Authenticationless ssh login

How to setup a user on a machine that anyone can connect to, without asking for a password. This is of course not something to do with a machine that exposes the ssh port to the internet, but I don't see how this would be so bad in a LAN).

So let's say we want to leave access to freeuser open.

1. Remove password : passwd -d freeuser
2. Allow empty password in /etc/ssh/sshd_config :

   PermitEmptyPasswords yes

3. Finally, depending on your distro, you might have to modify pam behaviour.

   For example, on debian systems, modify /etc/pam.d/common-auth by replacing the line

   auth    [success=1 default=ignore]      pam_unix.so nullok_secure

   by

   auth    [success=1 default=ignore]      pam_unix.so nullok