How to generate ssh keys on Linux

20 February 2019

Sometimes, by security or usability reasons authentication with SSH keys looks much better than passwords. To generate personal keys, please, do next:

Login your remote instance
Generate ssh keys by

ssh-keygen -t rsa -f ~/.ssh/[KEY_FILENAME] -C [USERNAME]
cat [KEY_FILENAME].pub >> ~/.ssh/authorized_keys

Download private key ([KEY_FILENAME]) to your local PC
Try to connect from your local with key:

chmod 400 [KEY_FILENAME]
ssh -i [KEY_FILENAME] [USERNAME]@yourhost.com

To disable root login and password based login refer to /etc/ssh/sshd_config and edid next sections:

PasswordAuthentication no
PermitRootLogin no

Then reload ssh server

sudo service ssh restart