Configure passwordless login in ssh

shakir    Information Insemination     linux, security, ssh

This post is just a quick recap on how to configure passwordless ssh login.

In my setting, herugrim is my local machine, and anduril is the remote machine with the ip address of 192.168.1.10

The first step is to (optionally) generate RSA key for use with SSH. Make sure you dont use any passphrase for this or you’ll later need to enter the passphrase upon login instead of password, which doesn’t really server our purpose here.

shakir@herugrim ~ $ ssh-keygen -t rsa -C shakir@192.168.1.10
Generating public/private rsa key pair.
Enter file in which to save the key (/home/shakir/.ssh/id_rsa): /home/shakir/.ssh/id_rsa.192.168.1.10
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/shakir/.ssh/id_rsa.192.168.1.10.
Your public key has been saved in /home/shakir/.ssh/id_rsa.192.168.1.10.pub.
The key fingerprint is: 11:d9:23:2e:68:05:59:d9:ac:5a:00:69:17:3a:b4:24  

Now we can copy the public key to the server. Instead of doing it manually, OpenSSH has a nice program to do just what we need:

shakir@herugrim ~ $ ssh-copy-id -i .ssh/id_rsa.192.168.1.10.pub shakir@192.168.1.10

So now lets test if our passwordless login is successful:

shakir@herugrim ~ $ ssh shakir@192.168.1.10 -i .ssh/id_rsa.192.168.1.10
shakir@anduril:~$

Great, it works The next thing to do is to just make sure you keep your private key safe..