[ietf-dkim] [Fwd: I-D ACTION:draft-fenton-dkim-threats-02.txt]

[Stephen Farrell]

Hi Doug,

Douglas Otis wrote:
> Stephen,
> 
> I will concede the term "policy" generally describes the SSP record.  

Good. I think its easier if we use the same terms.

> [...]  Any "open" policy exposes the email-address
> domain owner to unjustified complaint traffic.

No more than could happen today. I don't see any reason why complaints
will rise that couldn't happen right now.

 > However, "closed"
> policies also disrupt common email practices, and therefore are not 
> suitable for general use.

Probably not. But as I understand it, those are designed for special
(and not general) cases.


> A large domain has an advantage that a smaller domain does not.[...]

I don't see how we can design a protocol to level that playing
field.

> ... This problem in general also runs afoul of a desire to 
> not force the publication of "open" policies creating a paradox.

I don't see any paradox unless you want one domain with both
an open and a closed policy.

> There is a practical alternative to the SSP policy approach described in 
> the dkim-options that would entail far far less overhead and would not 
> impose the need for "open" policies.

I'll take a look.

> On Jan 12, 2006, at 6:17 AM, Stephen Farrell wrote:
> 
> Some small nits then:
> 
>> "Policies can be open or closed. Open policies define a set of 
>> conformant messages and are silent about other messages. Closed 
>> policies define the set of conformant messages and other messages do 
>> not conform to the policy.
> 
> Policy is not checked when the email/signing domains match.   Policy is 
> therefore silent when email/signing domains match.  When email/signing 
> domains do not match, SSP indicates whether unsigned or foreign signed 
> messages are acceptable.   With respect to open policies, _all_ such 
> messages are conformant and acceptable.

Nope. You're confusing the sender's policy statement with what
the verifier considers acceptable, which is out of scope.

I guess Jim can handle your other wordsmithing changes which
seem fine,

Cheers,
Stephen.