Install openssh with:
dnf install openssh
Configure ssh client
emacs /etc/ssh/ssh_config
Host * HashKnownHosts yes StrictHostKeyChecking ask Protocol 2
Configure ssh daemon
emacs /etc/ssh/sshd_config
Port 22 ListenAddress 0.0.0.0 # HostKey - do not change these lines; Host identity defers a man-in-the-middle attack. Protocol 2 PermitRootLogin no MaxAuthTries 6 MaxSessions 10 PubkeyAuthentication yes PasswordAuthentication no ChallengeResponseAuthentication no AllowUsers mihai
Open ssh port 22 in firewall (iptables)
Check /etc/hosts.allow and /hosts.deny
Start the service
systemctl enable sshd.service systemctl start sshd
Login to server with the user account and generate the ssh keys
Generate a RSA (Rivest-Shamir-Adleman) on 4096 bits -can be imported by Putty
ssh-keygen -t rsa -b 4096
The public key id_rsa.pub contains data for the server
The private key id_rsa contains private data for the client (mobile@localdomain)
cat ~/.ssh/id_rsa.pub cat ~/.ssh/id_rsa cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys chmod 600 ~/.ssh/authorized_keys
Copy the keys from the remote computer to local computer.
You should not be logged into the remote computer.
scp does not require a pre-existing ssh connection.
scp example 1
and
scp example 2
scp mihai@64.227.114.160:/home/mihai/.ssh/id_rsa /home/mihai scp mihai@$DIGITALOCEAN:/home/mihai/.ssh/id_rsa.pub /home/mihai
You can remove the keys from the server.
rm ~/.ssh/id_rsa rm ~/.ssh/id_rsa.pub
Restart ssh to test the new key.
systemctl restart sshd.service systemctl status sshd.service
You have now the private key (id_rsa) on client computer (mobile#localdomain)
mv ~/.ssh/id_rsa ~/.ssh/id_rsa_home_key chmod 400 ~/.ssh/id_rsa_home_key
I do not set a ssh-agent as I need to remember always the pass-phrase for my keys
Login into sshd on my home server (192.168.0.128, port 22)
ssh -l mihai -i ~/.ssh/id_rsa_home_key 192.168.0.128
ssh login with X11 forwarding
ssh -X -l mihai -i ~/.ssh/id_rsa_home_key 192.168.0.128
ssh login with tunnelling to C7 running in virtualbox
ssh -L 5903:192.168.0.18:5903 -i ~/.ssh/id_rsa_c7 -l mihai 192.168.0.18
Set up a connection alias
emacs ~/.bashrc
alias server='ssh -l mihai -i ~/.ssh/id_rsa_home_key 192.168.0.128'
# copy files into server's home over ssh
scp_copy(){
scp -i $HOME/.ssh/id_rsa_home_key $1 mihai@vasilian.net:$HOME
}
alias scp2server=scp_copy