SSH Logins without typing a Password

I connect to my desktop computer that runs Linux Mint from my MacBook Pro using SSH. I do this most nights, even just to power down the box.

To save having to type my password each time from my laptop, I configured SSH to allow my laptop to login securely without typing the password. Here's how:

Step 1: Use ssh-keygen to create public and private keys on my MacBookPro

MacBookPro:~ neil$ [Note: I am on the local-host here]

MacBookPro:~ neil$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/Users/neil/.ssh/id_rsa):[ENTER]
Enter passphrase (empty for no passphrase): [ENTER]
Enter same passphrase again: [ENTER]
Your identification has been saved in /Users/neil/.ssh/id_rsa.
Your public key has been saved in /Users/neil/.ssh/id_rsa.pub.
The key fingerprint is:
33:b3:fe:af:95:95:18:11:31:d5:de:96:2f:f2:35:f9 neil@MacBookPro

Step 2: Copy the public key to remote host (Linux Mint)

MacBookPro:~ neil$ cat ~/.ssh/id_rsa.pub | ssh neil@LinuxMint "mkdir ~/.ssh; cat >> ~/.ssh/authorized_keys"

Step 3: Login without a password using SSH

MacBookPro:~ neil$ ssh LinuxMint
Last login: Sun Nov 16 17:22:33 2008 from 192.168.10.2
[Note: SSH did not ask for password.]

neil@LinuxMint$ [Note: You are on the remote-host here]

At that is it!

There is another command called ssh-copy-id that will perform step 2 but this wasn't available on my MacBook Pro. You use that command like so:

neil@ubuntu$ ssh-copy-id -i ~/.ssh/id_rsa.pub LinuxMint
neil@LinuxMint's password:
Now try logging into the machine, with "ssh 'LinuxMint'", and check in:

.ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.