ietf-dkim
[Top] [All Lists]

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

2006-04-07 09:09:39

On Apr 7, 2006, at 8:20 AM, Michael Thomas wrote:

Stephen Farrell wrote:

Yes, but this was a non-goal. We've said all along that it could be done in an MUA, but not that it was generally a good idea to put in an MUA since DKIM is intended to have a transport lifetime relevance.

True. Maybe the wording on "x=" could make that clearer if it said that the value is "how long I expect the message to be in transit" rather than "signature expiration"?

You could, but the semantic is more of a "I don't want this to be in transit after X". You mentioned NNTP Expires, and I think that's a pretty good analogy, though not exact.

Unlike a news article, there is some danger this expiry time might generate a message bounce when it establishes a basis for refusal in a rule-set. Although these would not be the rules you and others would create, a provider may bounce a message as it passes an expiration while within their AU. With an expiry in place, disabling the account could be seen as a adequate response to a replay issue. A strategy where the signer relies upon message expiration to curtail abuse reports will also likely lead to expired messages then being refused.

If x= is retained, there needs to be some cautions added about handling messages within the AU.

-Doug

_______________________________________________
NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html