[SSH] SSH connection with users who don't have password set fails even with public key authentication only
I’ll introduce the issue where SSH connection fails even with public key authentication only when trying to connect with a user who doesn’t have a password set.
When trying SSH connection with the -v option, you get Permission denied (publickey).
ssh [email protected] -v
...
debug1: No more authentication methods to try.
Permission denied (publickey).
When “Permission denied (publickey).” is displayed, logs are written to /var/log/secure on the server, so let’s check it.
# tail -F /var/log/secure
Jun 28 18:44:57 host sshd[1370]: User your_username not allowed because account is locked
Jun 28 18:44:57 host sshd[1372]: input_userauth_request: invalid user your_username
Jun 28 18:44:57 host sshd[1372]: Connection closed by 123.123.123.123
It seems that the sshd_config setting prevents users without passwords from logging in via SSH, so let’s obediently set a password for the user.
passwd your_username
To improve security, it’s better to set passwords for users from the beginning. That’s all from the Gemba.