ubuntu - root login not possible through ssh

ubuntu 14.04 - Enable root login for ssh

If you are trying to log into root account of ubuntu system using ssh and you are getting permission denied error. You are quite sure that your password is correct but still you are facing this error. It means root account is disabled for ssh.
Follow the steps to enable it.

Open file /etc/ssh/sshd_config on your ubuntu system.
Replace line
PermitRootLogin without-password
with
PermitRootLogin yes
Restart ssh.
Now try to log into root account using ssh.