[ietf-dkim] Consensus point on ADSP

[Mark Delany]

>>>   Note:   ADSP is incompatible with valid DKIM usage in which a  
>>> signer
>>>      uses "i=" with values that are not the same as addresses in  
>>> mail
>>>      headers.  In that case, a possible workaround could be to add a
>>>      second DKIM signature a "d=" value that matches the Author
>>>      Address, but no "i=".
>>>
>
> I'll start by proposing text that we could use if we adopted an
> alternate definition of Author Signature based on the d= value only.
> Then I'll describe what I think we'll lose by going to that  
> definition.

Given that i= is an arbitrary value assigned by the signer, the  
question to me is what value does it add beyond what signed RFC2822  
headers can do just as well. Eg, why not set an rfc2822.Sender Field  
and sign that rather than invent i=?

IOW, what is the value-add in inventing yet another identity called  
DKIM.i= when we already have rfc2822.From, rfc2822.sender,  
rfc2822.resent-from, rfc2822.resent-sender and rfc2821.mailfrom?

Are you suggesting that DKIM.i= should have preference over signed  
RFC2822 identifiers?


Mark.