Setup script should offer to turn off password auth for sshd

[konklone]

Since whats_next.py complains about it, and it's easy enough to modify (append a line to the sshd config file), the setup script could:

• check for the existence of $HOME/.ssh/authorized_keys, and if present:
• ask the user if they're already set with a key and not using a password to log in, and if so:
• turn off password authentication and restart sshd.

I'm not good enough with bash to do this as a PR, unfortunately.

[konklone]

One complication that comes to mind is whether $HOME will resolve to the right place during sudo. In my case, I'm logging in to my DO box as root, so I'm not using sudo, and $HOME is where the heart is. Not sure about other situations.

[mkropat]

Not sure if this is a good idea. Every additional prompt during setup takes you one step further from a "one-click, easy-to-deploy" mail server, and should be weighed carefully.

I don't know any major cloud providers that provision VMs with a system account that can be remotely logged in to with a password, and Mailinabox doesn't create such a user, so as a security measure it's unlikely to make a difference.

Perhaps a "Disable Password-based Logins" action can be added to one of the tools/* scripts, so the whats_next.py instructions can be simplified to running a single command. It could guide the user through setting up an SSH public key. What tools/* script it belongs in, I'm not sure.

[konklone]

Not sure if this is a good idea. Every additional prompt during setup takes you one step further from a "one-click, easy-to-deploy" mail server, and should be weighed carefully.

Definitely - and this would only appear as a prompt if $HOME/.ssh/authorized_keys existed. But yeah, it depends on how important mailinabox's recommendation to not use passwords is.

I don't know any major cloud providers that provision VMs with a system account that can be remotely logged in to with a password, and Mailinabox doesn't create such a user, so as a security measure it's unlikely to make a difference.

Digital Ocean (which I'm using, and which the mailinabox site recommends) provisions VMs with password-enabled root accounts, unless you chose to create a keypair in advance and to select it during creation of the VM (it's not selected by default).

Perhaps a "Disable Password-based Logins" action can be added to one of the tools/* scripts, so the whats_next.py instructions can be simplified to running a single command. It could guide the user through setting up an SSH public key. What tools/* script it belongs in, I'm not sure.

Good call, in any case.