Linux SSH public key authentication

add_public_key.sh

[ ! -f ~/.ssh/id_rsa.pub ] && ssh-keygen -t rsa;
ssh <username>@<remote_machine> 'mkdir -p ~/.ssh; chmod 700 ~/.ssh'
cat ~/.ssh/id_rsa.pub | ssh <username>@<remote_machine> 'cat >> ~/.ssh/authorized_keys'

description.md

Linux SSH public key authentication

Server side

1. Edit etc/ssh/sshd_config:

• Uncomment PubkeyAuthentication yes

• Setup auth key values path with AuthorizedKeysFile .ssh/authorized_keys

• Set next configs to disable default password authentification (if you need it)

ChallengeResponseAuthentication no
PasswordAuthentication no
UsePAM no

2. Create .ssh folder: mkdir -p ~/.ssh
3. Applay access ruels to the folder: chmod 700 .ssh
4. Reload ssh server to apply changes sudo /etc/init.d/ssh force-reload

Client side

1. Gereate and add to ssh-agent SSH key
2. Copy public key value to authorized_keys:

cat ~/.ssh/id_rsa.pub | ssh <username>@<remote_machine> 'cat >> ~/.ssh/authorized_keys'