ietf-dkim
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Re: [ietf-dkim] Today's jabber

2006-05-18 12:23:10

On May 18, 2006, at 10:38 AM, Mark Delany wrote:

OLD:    TXT records are encoded as described in Section 3.6.1.

One of the big questions asked in that draft relates to the relationship between TXT and DKK semantics. Which one is authoritative and which one is a mirror? Or should base be authoritative and both the TXT and DKK simply be particular representations?

There could be two drafts, one for the TXT RR and the other for DKK RR. If presented at the same time as the base-draft, these two drafts might also be merged. It seems the base draft will need to resolve these issues in tandem anyway.


I guess by way of example. The MX RR only defines the contents and not the semantics, so perhaps DKK and TXT should do similar with the semantics defined in the base?

One reason for reviewing these two records together would be concerns regarding an algorithm transition. The manner the algorithm is represented within the key could be problematic. If this representation is different than the manner used on the TXT record, then offering fictitious signatures claiming a new, but fictitious, algorithm not supported by the verifier would be an easy exploit owing to an inability to confirm what the sender is offering. The verifier would accept the deprecated signature in the belief the sender offered a non-deprecated signature together with the deprecated, but that it is using an algorithm unknown to the verifier.

-Doug

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