These steps are verified and tested several times and works flawlessly.

1. Install openssh server

sudo apt-get install openssh-server

2. Remove previous .ssh directory (from home directory)

rm -r ~/.ssh/

3. Now Execute the below command. Leave all the field empty when asked.

ssh-keygen -t rsa

4. Execute the following commands after that

cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
sudo chmod go-w ~/
chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys
exec ssh-agent bash
ssh-add

That’s it.

You can test on your machine.

ssh-copy-id localhost
ssh localhost

When you ssh localhost, it will not ask you password again.