3

So, I am aware I can disable password authentication via ssh by modifying /etc/ssh/sshd_config by changing PasswordAuthentication Yes to PasswordAuthentication no. I want to ensure ssh logins can only be done via a keyfile for every user.

Is there a nice one-liner command that sets this option?

Kyu96
  • 137

1 Answers1

4

I successfully tested this:

sudo sed -E -i 's|^#?(PasswordAuthentication)\s.*|\1 no|' /etc/ssh/sshd_config
if ! grep '^PasswordAuthentication\s' /etc/ssh/sshd_config; then echo 'PasswordAuthentication no' |sudo tee -a /etc/ssh/sshd_config; fi

This will use sed to edit the file in-place. In addition to replacing whatever follows PasswordAuthentication with no, it will remove the comment at the beginning of the line, which is there by default on Ubuntu. If this command is run a 2nd or 3rd time, there will be no additional change to the file.

The second line adds the config option to the file in case it was deleted somehow.

bitinerant
  • 758