Use Only Key File to Login Linux Server

Beginner guide for SSH keyfile login

Use Only Key File to Login Linux Server

This is a simple guide only for Linux beginners, showing the steps to use only key file to login Linux server and disable password login.

  • Assume that you are now logged as root
adduser ariel
usermod -aG sudo ariel
nano /etc/ssh/sshd_config
  • Modify the following:
    PasswordAuthentication no
    PubkeyAuthentication yes
    Note: If you have any .conf file in /etc/ssh/sshd_config.d/, which has any content of PasswordAuthentication yes, you can either change the value to no or simply delete the conf file(s).
  • Generate key file (for the prompts just hit enter)
su - ariel
cd ~/.ssh
ssh-keygen -t rsa
  • Copy publickey
cat >> authorized_keys
  • Save the privatekey to local
cat id_rsa

Copy the content and paste it to your_key_name.pem in your local computer

  • Restart sshd of your server
systemctl restart sshd
  • On your local, change permission
chmod 400 /your/key/path/your_key_name.pem
  • Login with key file
ssh -i /your/key/path/your_key_name.pem ariel@your-server-ip

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