Configure SSH on a VPS

Context

I am not a teacher, this is my own, an insignificant student, Aaron (Iso) Pescasio's notes.

Instead of allowing password authentication on my VPS, I wanted to remove it and enforce SSH key authentication.

First, I generate an SSH key.

ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

I press the "Enter" key 3 times, then copy the full content of the generated .pub file.

I connect to my server.

ssh username@Your_VPS_IPv4 -p PortNumber

I create the ~/.ssh/authorized_keys file (if it doesn't already exist) and paste the content of the .pub file into it.

nano ~/.ssh/authorized_keys

Finally, I disable password authentication and restart the SSH service using this bash script.

update-sshdconfig.sh

sudo sed -i "s/^#PasswordAuthentication yes/PasswordAuthentication no/" /etc/ssh/sshd_config
sudo systemctl restart sshd

I reconnect to my server and normally no password will be asked.

ssh username@Your_VPS_IPv4 -p PortNumber