ssh-hardening

To disable root login and enforce SSH key authentication, you must create a non-root sudo user, deploy your SSH key pair, and modify sshd_config to disable password authentication. This prevents unauthorized access to your VPS deployment.

Setting up a non-root sudo user for SSH hardening involves creating a new user account, granting it sudo privileges, and verifying sudo access. This ensures you can execute administrative commands without logging in directly as root.

Yes, SSH hardening works across Ubuntu, Debian, CentOS, and RHEL environments. The process applies during initial server setup or security overhauls on Linux-based VPS deployments in both cloud and on-prem environments.

You can test sshd_config changes before applying them by verifying configurations in a new SSH session. Safe operational practices dictate keeping your current session active to rollback changes if needed, preventing administrator lockout.

To generate and deploy SSH keys, create an SSH key pair on your local machine, copy the public key to the server's non-root user, and then harden sshd_config to disable password authentication entirely.

Disabling root login prevents unauthorized access because it eliminates the default administrative target that brute-force attacks exploit. By requiring key-based authentication through a non-root sudo user, access is cryptographically restricted to authorized administrators.