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2016-08-06 Ubuntu-Debian

How To Setup Key Based Ssh Authentication

How to Setup key-based (SSH) authentication on your Server#

  1. Create the key pair on client

    ssh-keygen -t rsa

    Convention over configuration keep the default location

  2. Install the public key on remote server

    ssh-copy-id -i $HOME/.ssh/id_rsa.pub user@fixes.co.za

    Not if you don’t have the private key you need to use the -f option:

    ssh-copy-id -f -i $HOME/.ssh/id_rsa.pub user@fixes.co.za

    or

    scp $HOME/.ssh/id_rsa.pub user@fixes.co.za:~/.ssh/authorized_keys
    No ssh-copy-id installed?#
    First create .ssh directory on server

ssh user@fixes.co.za umask 077; test -d .ssh || mkdir .ssh

cat local id.rsa.pub file and pipe over ssh to append the public key in remote server

cat $HOME/.ssh/id_rsa.pub | ssh user@fixes.co.za cat >> .ssh/authorized_keys

  3. Test

    ssh -T user@fixes.co.za

or

scp foo.txt user@fixes.co.za:/tmp

    Get rid of password:

    eval $(ssh-agent)

    add passphrase for private key maintained by ssh agent

    ssh-add

    Try login you shouldn’t be prompted for password

    ssh user@fixes.co.za

Now to Disable Password Authentication on your server#

sudo vim /etc/ssh/sshd_config
Set:#
PasswordAuthentication no

Restart SSH

sudo service ssh restart
Sources:#