Sshkeys

New Machines with OpenSSH

Setting up SSH keys between newer computers with OpenSSH (such as Hobart) is very simple.

On your machine, as you, enter the following commands.

ssh-keygen -t rsa

Press enter for default location
Press enter for empty passphrase twice

scp $HOME/.ssh/id_rsa.pub oper@hobart:/home/oper/ (Enter password as usual)
ssh oper@hobart (Login as per usual)
cd .ssh

If there's already a list of authorized keys, you need to append yours, after making a backup.

cp authorized_keys2 authorized_keys2.old
cat authorized_keys2 ../id_rsa.pub >> authorized_keys2
rm ../id_rsa.pub
chmod 600 authorized_keys2

If no authorized_keys2 file exists, then just use

touch authorized_keys2
cat ../id_rsa.pub >> authorized_keys2
rm ../id_rsa.pub
chmod 600 authorized_keys2

Log out of hobart and try ssh'ing. You should be logged in automatically without any prompt for a password or passphrase.

Older machines without SSH2

For older machines such as ceduna which don't support SSH2, the recipe is slightly different

ssh-keygen -t rsa1

Press enter for default location
Press enter for empty passphrase twice

scp $HOME/.ssh/identity.pub oper@hobart:/home/oper/ (Enter password as usual)
ssh oper@hobart (Login as per usual)
cd .ssh

If there's already a list of authorized keys, you need to append yours, after making a backup.

cp authorized_keys authorized_keys.old
cat authorized_keys2 ../identity.pub >> authorized_keys
rm ../identity.pub
chmod 600 authorized_keys
If no authorized_keys2 file exists, then just use

touch authorized_keys
cat ../identity.pub >> authorized_keys
rm ../identity.pub
chmod 600 authorized_keys