DKIM extension tags feature

From: Murray S. Kucherawy <msk_at_blackops.org>
Date: Thu, 7 Apr 2011 16:23:09 -0700 (PDT)

Some debate on the IETF DKIM mailing list is occurring around the ability
to extend DKIM, adding new tags to signatures for various reasons. If you
have some special arrangement with a verifier someplace, you might find it
helpful to be able to add details about the message author that can't
already be expressed through the "i=" tag (which is already supported).

There aren't any specific use cases for this yet, but one example is a
birthdate, which you might encode as "bd=yyyymmdd".

I've already crafted a patch to add support for this to libopendkim in the
next major release (later this year), but now I need to find a good way to
add this to the filter's configuration. My current plan is to add a new
data set called "ExtensionTags" that would would be queried the same way
SigningTable is queried; the filter would expect an even number of values
returned, in tag-value pairs.

Does that sound reasonable? Would tying it to the SigningTable make more
sense? Is there a better idea?

-MSK
Received on Thu Apr 07 2011 - 23:23:25 PST