HowTos/Passwordless SSH

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Passwordless SSH

SSH keys come in pairs, a private key which you want to keep secret and locked with a password, and a public key which you can give away (or store on remote computers which then use it to trust incoming connections from you).

To create an ssh key, use "ssh-keygen -t rsa -b 2048". Save the key pairs to .ssh in your home directory. It's important to use a strong passphrase, with letters, numbers and punctuation - not a word from the dictionary nor a word where numbers are put in place of letters (e.g. "p455w0rd" as password cracker software tries this).

To keep the ssh key secure and yet not need a password every time, use "ssh-agent" which stores the private key. Simply run "ssh-agent" in your startup script and ensure the environment variables it spits out are set in your shell.

Then, add your key to the agent with "ssh-add".

From now on, when you ssh to a remote system which has your public key in the .ssh/authorized_keys file, it should allow you to log straight in. If there's a problem, use "ssh -v" to tell you what it's doing.

NOTE - Password-less keys

It is possible to create a password-less ssh key pair, but this is dangerous and should only be used when you FULLY understand the impact on security!