Linux Desktop Hacks

Create a Passwordless Login #78

Chapter 9, Administration and Automation

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239

HACK

Create the Login

With the keys generated, the next step is to upload the public key to the

remote server. If you have never dealt with SSH keys before, you probably

do not have a .ssh/authorized_keys file on the remote server. If this is the

case, you can simply copy the id_rsa.pub to the remote server and call it .ssh/

authorized_keys:

foo@local:~$ scp id_rsa.pub foo@remote:/home/foo/.ssh/authorized_keys

If you have already created an authorized_keys file on the remote server, you

can simply log in to the remote server, open authorized_keys in a text edi-

tor, and paste the contents of id_rsa.pub on the local machine into the file

on a new line. This is how you add multiple keys on the remote server.

Whichever method you use to get your public key on the remote server, you

must set the permissions on the files and directory correctly. Simply issue

the following commands:

foo@remote:~$ cd ~/.ssh

foo@remote:~$ chmod 700 ./

foo@remote:~$ chmod 600 *

These commands ensure that your .ssh directory and files are secured.

Finally, on the local machine, copy the generated id_rsa file to the .ssh in

your home directory to make it the default key for SSH:

foo@local:~$ cp id_rsa ~/.ssh

Now you can test to see that the connection works:

foo@local:~$ ssh foo@remote

You should be able to log in automatically with no password prompt.