[ietf-dkim] Are verifiers expected to query SSP on a successful verify?

[Stephen Farrell]

John Levine wrote:
>> Scenario 3a:
>> 1) A is a popular phishing target and prefers to suffer message
>> rejections for messages that don't carry a valid signature by A (or a
>> designated third party) than to have messages that are unsigned or
>> signed by other parties delivered.
>> 2) C sends message on A's behalf using C's identity.
>> 3) B would like to know if C's signature has any relationship to A.
>> 4) If C's signature does not have a relationship to A, then A prefers
>> that the message not be accepted for delivery
> 
> This is the same as scenario 1.  The message doesn't have A's
> signature, B wants to know if that's OK.  The set of possible C's that
> we don't trust is unlimited, and I can't see any point in trying to
> enumerate them.

I *think* he was trying to differentiate between:

- A says that he signs everything, and,

- A says that he signs everything and if A's sig is missing/bad A would
   like verifiers to drop/kill/whatever the message.

I've no idea if that 2nd one ought be a requirement for ssp, but I do
see the difference (and the fact that there're ratholes there!)

S.