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Public key authentication allows you to login to a remote host via the SSH protocol without a password and is more secure than password-based authentication. Try creating a passwordless connection from linuxconfig.local to linuxconfig.org using public-key authentication.

1. Create key

Press ENTER at every prompt.

linuxconfig.local$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/user/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/user/.ssh/id_rsa.
Your public key has been saved in /home/user/.ssh/id_rsa.pub.
The key fingerprint is:
b2:ad:a0:80:85:ad:6c:16:bd:1c:e7:63:4f:a0:00:15 user@host
The key's randomart image is:
+--[ RSA 2048]----+
| E. |
| . |
|. |
|.o. |
|.ooo o. S |
|oo+ * .+ |
|++ +.+... |
|o. ...+. |
| . .. |
+-----------------+
linuxconfig.local$

For added security '''the key itself''' would be protected using a strong ''passphrase''. If a passphrase is used to protect the key, ssh-agent can be used to cache the passphrase.

2. Copy key to remote host

linuxconfig.local$ ssh-copy-id This email address is being protected from spambots. You need JavaScript enabled to view it.
 
This email address is being protected from spambots. You need JavaScript enabled to view it. 's password:
Now try logging into the machine, with "ssh 'This email address is being protected from spambots. You need JavaScript enabled to view it. '", and check in:

.ssh/authorized_keys

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

3. Login to remote host

Note that no password is required.

linuxconfig.local$ ssh This email address is being protected from spambots. You need JavaScript enabled to view it.
 
Last login: Tue Apr 3 12:47:53 2007 from 192.168.0.39
linuxconfig.org#

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