[ietf-dkim] Choices about Practice vs. Publication

[Douglas Otis]

On Jul 8, 2007, at 4:46 PM, Steve Atkins wrote:

>
> On Jul 8, 2007, at 4:37 PM, Douglas Otis wrote:
>
>>
>>>   Steve pointed out to me that a basic challenge, here, is that  
>>> DKIM does not define a signature as meaning that the signer is  
>>> asserting the truthfulness of any particular bit of information  
>>> in the message.  That's the inherent difference between the mild  
>>> "taking responsibility" semantics that we have given to a DKIM  
>>> signature, versus "asserting correctness" or the like.
>>>
>>>    My suggestion to deal with this is to define the basic DKIM  
>>> sematnic that all DKIM-* headers are asserted to be valid, if  
>>> they are included in the signature.
>>
>> This assertion in many cases would need to exclude the From  
>> address, but this header is required to be signed.  Use of the  
>> "i=' parameter is likely the only positive means to communicate  
>> such an assurance and is already defined within DKIM base.
>
> "From" does not start with "DKIM-".

The From: field is intimately combined with the DKIM-Signature: field.

Per rfc4871:
---
5.4. Determine the Header Fields to Sign

  The From header field MUST be signed (that is, included in the "h="
  tag of the resulting DKIM-Signature header field).
___

Are you suggesting the intent is to sign other DKIM-Signatures and  
thereby assert they are also valid?

-Doug