There are two main methods for SSH authentication: the standard user name and password, and Identity key pair.
Identity key pair authentication allows you to log in to the server without having to supply a password. Here is how it works. You generate a private and public key associated with a username to establish that user's authenticity. When you attempt to log in as that user the user name is sent to the server. Next, the server looks in the user's .ssh directory for the user's public key. A challenge is then sent to the user based on his or her public key. The user verifies his or her identity by using the private portion of the key pair to decode the challenge. Once this happens the user is logged in without the need for a password. This is especially useful when automating remote scripts.
To generate the public key pair use the following command on your client machine:
ssh-keygen -t dsa
When prompted for a passphrase and verification, press Return both times without entering a passphrase. Copy the resultant public key to the user's home directory in .ssh/ on the server machine. The next time you log into the server from the client machine you won't need to enter a password.
Date Created: 2006-04-05 16:12:00 Date Last Modified: 2006-04-05 16:12:00