Remote signing

[Dave Symonds]

On Tue, Apr 20, 2004 at 01:28:35PM +0100, Stuart A Yeates wrote:
> >The Sun does all the normal mail handling, but there is no console that I
> >use to access it directly (only via ssh).  The ssh connection from my 
> >laptop
> >to the Sun is the only true TCP connection (made easier with a ssh keypair,
> >private key on laptop). Other things can be tunnelled through the ssh
> >connection.
> 
> It's still not clear where are the (ssh, gpg) keys stored, where are the 
> gpg cryptographic operations are performed and where the passwords and 
> passphrases are input and transfered.

All private keys are kept on the laptop, as is the GPG operations. The
passphrases are entered directly onto the laptop. Emails are entered into
the Sun via the ssh tunnel, but the actual privacy is not really an issue,
only the integrity.

> If the ssh connection is establishable automatically, then an attacker 
> who has compromised the Sun can estalish a connection to the laptop. If 
> the connection is to a general purpose account, all sorts of badness may 
> result.

The ssh connection that is opened from the laptop to the Sun is opened on
the laptop, and the "returning" connection for the signing is tunneled
through this existing connection.

Dave.

-- 
David Symonds
USyd::SITRG::PhD Student
http://www.it.usyd.edu.au/~dasymond/