Easy SSH Login
Here is a simple way to setup key (password-less) login on Unix-like systems.
Once you’ve configured SSH locally, add your public key to remote hosts using the following command:
**NB** in the next line, be very careful to use cat >> (append) and not cat > (overwrite), or you will trash your remote authorized_keys2 file, leaving your remote inaccessible to everyone but you. Not cool.
cat ~/.ssh/id_rsa.pub | ssh remote_machine 'cat >> .ssh/authorized_keys2'
Replace .ssh/id_rsa.pub with your public key.
Also make sure remote folder ~/.ssh has mode 0700 and ~/.ssh/authorized_keys2 has 0600.