On Fri, 2004-09-17 at 23:14 -0700, Jim Fenton wrote:
Which raises a good question: shouldn't the sender have something to
say about this? Might some senders insist that their messages are
sent perfectly in order to verify their signature, while others might
be more lax (perhaps because they know they're going through a mailing
list)?
IMHO, no. Too many people add pointless virus-checker adverts and
disclaimers in transit. Personally I'd _like_ to sign my message with a
prohibition on such idiotic additions, but I don't think that really
promotes interoperability and hence isn't really something we as a
working group should advocate.
The message contains a clear indication of what the sender _did_ write.
The MUA could display that part in a different colour, or on a different
background -- or even choose to omit the additions altogether. I would
be inclined to suggest that this is enough.
Both DomainKeys and the next revision of IIM have provision for
specifying a canonicalization (see the b: tag on the IIM-Sig header on
this message for a sample). Should we have a signature for the strict
(non-canonicalized) form of the message as well, to give that option
to the recipient as well?
I don't think so. I find it hard to imagine an attach in which
canonicalisation gives you a way to abuse mail. Perhaps if the
canonicalisation were to fold all whitespace, someone's answer could be
moved from one column in a table to another column?
But that's a somewhat different problem -- I really don't see how it
could be abused as a spam vector.
If people are sending mail which is _so_ important to keep precisely as
it was sent, there are existing schemes which address that -- PGP and
S/MIME. That's not an interesting problem space, I think.
--
dwmw2