Friday, July 10, 2009

HOWTO : SSH to use RSA key for login

Generate RSA key.

ssh-keygen -t rsa -b 2048

or

ssh-keygen -t rsa -b 4096

“Enter file in which to save the key (/home/samiux/.ssh/id_rsa): (Hit Enter)”

Press “Enter”

“Enter passphrase (empty for no passphrase):”

Enter your password twice.

nano /home/samiux/.ssh/id_rsa.pub

Copy the content.

SSH to your server. At the username directory.

sudo mkdir .ssh
sudo nano /home/username/.ssh/authorized_keys

Then pasted the previous copied key onto the authorized_keys file. Save it.

Still at the server.

sudo nano /etc/ssh/sshd_config

Change the following settings as is.

AuthorizedKeysFile %h/.ssh/authorized_keys
IgnoreUserKnownHosts yes
PasswordAuthentication no
#UseLogin no
UsePAM no

sudo /etc/init.d/ssh restart

When you login to the server again, you will ask for your RSA key passphrase once. Later, you will not be asked for any passphrase or password in the same session.

For Ubuntu Desktop users, you may consider to install SSHMenu. It will make your work more easily.

http://sshmenu.sourceforge.net/
That's all. See you!