[ietf-dkim] DKIM Interoperability Event notes

[Hector Santos]

Murray S. Kucherawy wrote:
> On Thu, 8 Nov 2007, Hector Santos wrote:
>> Attackers will be able to create a FAILED fascimile of a primary 
>> domain DKIM complete message and as long as the primary has a t=y 
>> policy, the attackers need not worry about HASH PERFECTION - it just 
>> randomly creates a signature with a junk hash because the t=y will 
>> promote a IGNORE FAILURE concept.
> 
> OK so in fact the complaint is "t=y is dangerous", not "a hacker could 
> insert t=y into someone's policy" (which is what you originally said). 
> There are other people here who can debate that as well as or better 
> than I so I'll yield.

Ok, I didn't say insert, but I can see how it was read.  I stated:

   It is clearly a threat entry point allowing anyone to try to
   create a DKIM signature and all they have to do is add t=y with
   the hope the receiver will ignore all fail validations.

I should of been clear of saying "exploited domains who added t=y into 
their policy":

   ... and all they have to do is find a DOMAIN with a t=y policy...

> In sticking to the Subject: of this thread, no, this was not discussed 
> at the Interop event.  SSP was determined early on to be out-of-scope 
> for our tests.  We were focusing only on RFC4871 itself.

How unfortunate.

> It was felt, though, that SSP might be the subject of a future Interop 
> event once the draft has become an RFC (or, perhaps, multiple proposals 
> are available).

Its unfortunate that SSP continues to be play 2nd fiddle when in fact, 
in my mind, DKIM is worthless (offers little payoff) without a POLICY 
concept.  I won't recommend DKIM until SSP is part of the fundamental 
picture.

Anyway, I won't go there.  I just hope the t=y comments are not ignored.

Thanks for your own comments.

-- 
Sincerely

Hector Santos, CTO
http://www.santronics.com
http://santronics.blogspot.com