Ssh no pass

From Cryptolife

Sometime is better don't have a password rather than have a weak one. I strongly advise to use this method only with an encrypted file system , because without adequate protection your ssh keys can be easily copied and the remote system might be compromised. In this short how-to I'm going to explain how to log in via ssh without password and use the ssh-copy-id to upload the ssh key to the remote system, ssh-copy-id also changes the permissions of the remote user's home, ~/.ssh, and ~/.ssh/authorized_keys to remove group writability (which would otherwise prevent you from logging in, if the remote sshd has StrictModes set in its configuration).
 

1)Ssh keys generation

test$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/test/.ssh/id_rsa): server1
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in server1.
Your public key has been saved in server1.pub.

ls -la ~/.ssh/

total 68
drwx------ 2 test test 4096 2010-03-23 11:23 .
drwxr-xr-x 109 test test 4096 2010-03-23 11:16 ..
-rw-r--r-- 1 test test 53044 2010-03-23 10:51 known_hosts
-rw------- 1 test test 1675 2010-03-23 11:23 server1
-rw-r--r-- 1 test test 402 2010-03-23 11:23 server1.pub

2)Secure ssh key copy to the remote server.

ssh-copy-id -i server1.pub user@remoteserver

user@remoteserver's password:
Now try logging into the machine, with "ssh user@remoteserver", and check in:

.ssh/authorized_keys

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

3)Ssh remote login test.

ssh -i ~/.ssh/server1 user@remoteserver

user@remoteserver#

You're done!