On 12/10/2022 2:15 PM, Al Iverson wrote:
That the charter said "during transit" is a perfectly fine and accurate response that misses the point slightly -- that other folks did and do see the value of post-transit use of DKIM, and that there is significant usage of it in this way today, and to me, it seems unreasonable to wholly discount that. Perhaps the documentation doesn't align with common usage. Point granted, but simply holding up a sign that says that and implying that this thus solves some level of the problem doesn't seem right to me. There'd be an awful lot of existing, current usage to unwind there to get back to your desired square one, and I'd argue that there's value and utility to lose by doing so.
There is usage that is reasonable, in terms of the technology, administration, and operations involving DKIM. And then there is usage that is not reasonable. On the basis of only DKIM, for example, making assertions about the authenticity of the rfc5322.From field contents is something that is often cited but never valid. So we need some care in considering which uses to cover here and which to ignore or even explicitly exclude.
I think a simple -- and hopefully not too simplistic -- question to consider in the context of replay and other misuses of DKIM, is when is it reasonable to make a fresh validation effort invalid? When should a random, remote agent no longer be able to 'validate' the signature?
This does not have any effect on how to handle results from an earlier validation, but only later retrieval and use of the public key, I think.
So let's at least distinguish between post-delivery validation and post-delivery use of an earlier validation.
d/ -- Dave Crocker Brandenburg InternetWorking bbiw.net mast:@dcrocker@mastodon.social _______________________________________________ Ietf-dkim mailing list Ietf-dkim@ietf.org https://www.ietf.org/mailman/listinfo/ietf-dkim
