Subject: Re: Multipart non-clearsigned messages possible?

From: "Housley, Russ" <[email-masked]>
Date: Tue, 10 Sep 2002 18:58:58 -0400

While the protocol support the signing of arbitrary MIME objects, it
would be quite difficult to write a mail client user interface that
allows the user to select a subset of the message to be covered by the
signature.  So, in practice, we have seen sign-it/do-not-sign-it as
the user interface.

That said, I think that it is very likely that application-to-application
communications will be developed that encrypt and sign selected portions
of a larger data transfer.  I think this is likely because there is
not a user interface issue.

Russ

At 11:40 AM 9/9/2002 +0100, Elanor Foley wrote:

Hello
all,

This may seem like a silly
question, but is it possible to have a multipart, non-clearsigned s/mime
message?

My current thinking is

a) it's not possible: the whole
message gets signed, including attachments.

b) it's possible: some part(s)
of the message get signed, other parts, e.g. audio file, can be attached
without being signed. The verification is only computed across the
eContent inside the signedData anyway.

If b), does anyone know of an
example I could look at (incl. headers)?

Thanks,

-
Lnr