On Apr 7, 2011, at 5:13 AM, Charles Lindsey wrote:
On Wed, 06 Apr 2011 17:29:49 +0100, Steve Atkins
<steve(_at_)wordtothewise(_dot_)com>
wrote:
As a concrete example, if I wanted to include the authenticated
age of each email sender (something the gambling industry might
be interested in) then I can do that within the DKIM signature:
DKIM-Signature: v=1; d=corp.example.com; <blah>; db=19700224
Actually, what you want is a gerenal purpose txt or comment header, in
which the signer can place any remark that he considers worthy of his
signature (including the capacity in which he is adding his signature -
another feature that people argue about).
E.g. DKIM-Signature: v=1; d=corp.example.com; <blah>;
tx="birthdate=1970-02-24"
or DKIM-Signature: v=1; d=corp.example.com; <blah>;
tx="signed by List Expander"
I suppose such a tag would have to be an extension to avoid recycling at
Proposed.
It's not machine readable and has no semantics - so a sender who just
wants to stash human readable trace or advertising content (a-la User-Agent)
could use a 5322 field just as well, possibly the "Comments".
If the thought is (as your first example seems to imply) that it's
a plain text field in which any implementor can make up a syntax
for adding additional fields then I think that's probably a bad idea
and would end up just being used to end-run around the tag
registry, and likely lead to all sorts of grungy heuristic hacks (much
as we see in TXT records in DNS, but worse as there's no namespace).
Cheers,
Steve
_______________________________________________
NOTE WELL: This list operates according to
http://mipassoc.org/dkim/ietf-list-rules.html