On Wed, Dec 17, 1997 1:26 PM, Paul Hoffman / IMC <phoffman(_at_)imc(_dot_)org>
wrote:
David, I'm not sure what you *would* put in the signature and the cert,
then. When I receive a signed message, I want to verify that it came
from someone I trust. The "came from" information is in the unauthenticated
RFC822 headers. With some DN in the signature and cert, I can verify that
the signature was made by someone our mutually-trusted CA says it does, but
there is no binding between that and the message I received.
The "came from" information is in the authenticated attributes of the
cert. Imagine the cool new S/MIME e-mail client that displayed the
sender certificate's subjectAltName (or whatever) instead of the rfc822
From: to tell you who sent the message.
My question is, if we don't use mail addresses in mail signatures and
certs, what do we use? Or, are you suggesting we say "you cannot
validate signatures on email as being associated with them messages"?
The only binding that is important is that between the cert and the
signature which is provided by the signature validation process. The
user says, "I have a signed message that can be validated by the 'Paul
Hoffman' cert so I know Paul sent the message. The rfc822 From: field
says <anon(_at_)remailer(_dot_)net> but I still know it's Paul because of the
cert
so I'm happy."
--
Ron Craswell
Worldtalk Corp.