Re: Comments on draft-allman-dkim-base-00.txt

[Thomas Roessler <tlr@xxxxxx>]

On 2005-08-03 14:44:13 -0700, Jon Callas wrote:

> Forwarding, as in the MUA command, does frequently break things.
> This is one of my peeves with MIME mail in general. This is a
> problem with MIME, not with signing, however. I'm -- umm --
> notorious? -- for my dislike of MIME email of any sort, and the
> reason is that MUAs seem to handle it so badly. For example, my
> usual airline insists on sending itineraries in MIME with lots of
> prettiness in it, and if I want to forward my itinerary to
> someone (and still expect them to meet me at the airport), I have
> to render it into PDF and send the PDF.

I'm wondering about the relevance of that observation in the context
of DKIM -- is there any reason at all to assume that forwarding in
the MUA sense will leave a DKIM signature intact?

My guess would be that simple encapsulation in a message/rfc822 body
would leave it intact, but that's the case which works well for
multipart/signed, too.  

The cases that would break multipart/signed look like they would as
well (or even more likely -- consider the impact of forwarding on
headers) break DKIM signatures.


(Which leaves your observation that there are lots of bad MUAs out
there.  No doubt about that.)

Regards,
-- 
Thomas Roessler, W3C   <tlr@xxxxxx>