Login to LINUX / Unix box using SSH without password

Here is a mini HOWTO to SSH onto a UNIX Box without typing password.


Server: LINUXSERVER (user --> linuxuser)
Client: iMAC ( user --> demouser)

• Generate Authentication keys using ssh-keygen on client

$ ssh-keygen -t rsa 

Generating public/private rsa key pair.

Enter file in which to save the key (/home/demouser/.ssh/id_rsa): 

Enter passphrase (empty for no passphrase): 

Enter same passphrase again: 

Your identification has been saved in /home/demouser/.ssh/id_rsa.

Your public key has been saved in /home/demouser/.ssh/id_rsa.pub.

The key fingerprint is:

xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx demouser@iMAC

The key's randomart image is:

+--[ RSA 2048]----+

+-----------------+

• Copy the id_rsa.pub to server onto $HOME_DIR/.ssh/authorized_keys2
• Setup a symbolic link to authorized_keys

          ln -s authorized_keys2 authorized_keys

• chmod 0600 on authorized_keys2 & authorized_keys file

Testing 

• From the client try ssh linuxuser@linuxserver, ssh shouldn't ask for password.