ietf-dkim
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Re: [ietf-dkim] Proposal: get rid of x=

2006-04-11 19:04:51
At 5:43 PM -0700 4/11/06, Dave Crocker wrote:
Paul Hoffman wrote:
At 7:46 AM -0700 4/11/06, Michael Thomas wrote:
But that's
a much different proposition than saying that they will be able to
validate them whenever they get around to reading them. That is not
the problem we set off trying to solve.

If the WG agrees with that last sentence, then many parts of -base need to be rewritten. Currently, the protocol document puts no limit on quickly the recipient is expected to do the validation.


The focus on transit-related validation -- as distinctly different from open-ended, long-term validation, has been fundamental for the entire life of this effort.

Then that should be stated in the document, not just in the lore of the WG. If it is there and I missed it, I apologize, but I don't see it. Further, nothing in the discussions of MUAs doing validation seem to talk about the obvious case that an MUA might do first validation long after "transit".

Further, section 6.4 makes no sense and has to be eliminated or seriously re-written. You can't put a header in a message for a fact that will become untrue in the future.

The header simply says that the
message was validated. Not that it can be validated at some point in the future.

There is a huge disconnect here. x= is *not* talking about the ability to validate at some point in the future; it talks about a message that is valid at one point becoming invalid at a later point.

The text in draft-kucherawy-sender-auth-header-03, which is a normative reference from dkim-base, gives the following semantics for the "pass" label:
        sending domain publishes an authentication policy of some kind,
        and the message passed the authentication tests
Note the past tense used: "passed the authentication tests". In a normal environment, that is sufficient for a MUA to give a sensible notice. But in an environment where a message can be valid at one moment and invalid at the next, that is not sufficient to tell the MUA what to display at any particular time.

Is this clearer?

Further, section 6.5 will have to be re-written as well to say that when passing the signature validation information to higher-level processes, they will need to come with the time after which the signature is no longer valid.

huh?  why?

So that the higher level process can determine when the signature on the message is no longer valid. Think of it this way: Two people look at a check. One says to you "this check written out to you is for $100", and the other person says "this check written out to you is for $100, but it is no longer valid after tomorrow". Both those statements are true, but the only the second statement is useful in making a policy decision about what you should do with the check.
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