On Nov 28, 2007, at 11:35 AM, Jim Fenton wrote:
Michael Thomas wrote:
Frank Ellermann wrote:
So the implication here is that that sort of domain could never run
a mailing list that resigns messages? That doesn't seem right to me.
That's precisely one of the motivations for the local-part of the i=
tag. If a message from this list, for example, were signed with i=ietf-dkim(_at_)mipassoc(_dot_)org
, the signing address would not match jdoe(_at_)mipassoc(_dot_)org, so there's
no confusion about whether it's an originator signature or a mailing
list signature.
1) The i= parameter must include the localpart to help ensure on who's
behalf the message was signed.
(This might be helpful when the the identity is found within a Sender
header instead of the From header.)
2) The localpart must be included within the i= parameter to ensure on
who's behalf the message was signed, but _only_ when the localpart has
been authenticated.
3) The localpart must be included within the i= parameter whenever a
restricted key is used, but where the localpart may not have been
fully authenticated when wildcards are employed.
It is not clear whether the localpart included within the i= parameter
actually implies authentication. I'll even bet that it doesn't in
many cases.
-Doug
_______________________________________________
NOTE WELL: This list operates according to
http://mipassoc.org/dkim/ietf-list-rules.html