Re: SSH Passphrase

["Janus N." Tøndering <janus () bananus dk>]

If you use a password protected keyfile you need to have ssh-agent
running to do password-less logins. You can let ssh-agent span over
several sessions by setting the SSH_AUTH_SOCK environment variable to
the same as the session where you ran ssh-agent. If you do not use
passphrases you can only protect the key using basic file permissions.

Under all circumstances you have to trust root on the machine you store
your key. root can always get the key and if you password protect it but
use ssh-agent he can do the same SSH_AUTH_SOCK trick and bypass the
needed password. Also, the box could be cracked and assuming the cracker
has root he will have access to the scp system with trouble at all.

Janus

On Wed, 2003-03-05 at 22:06, Stefan Lesicnik wrote:
> Hi, 
>
> Im fairly new to private and public key encryption, so dont quite
> understand all the concepts.
>
> I have the need to scp a file to a remote server without specifying the
> password as it is done from a non-interactive script.
>
> I have accomplished this by generating a dsa key without a passphrase.
> Although this works I am worried about the security concerns of doing
> this? (Without a passphrase, how does it authenticate? Based on the
> machines dsa key which was made from machine specific entropy?)
>
> I know of programs such as ssh-agent, but these require you to enter a
> passphrase at the beginning of the session which it then remembers, this
> isnt possible as it is non-interactive in my case. Does anyone have any
> ideas or comments?
>
> TIA
> Stefan Lesicnik
-- 
Janus N. Tøndering <janus () bananus dk>