Re: [ietf-822] one can re-sign without a permission to re-sign header

Douglas Otis <doug.mtview@gmail.com> Fri, 27 June 2014 21:48 UTC

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From: Douglas Otis <doug.mtview@gmail.com>
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Date: Fri, 27 Jun 2014 14:48:50 -0700
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To: John Levine <johnl@taugh.com>
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Subject: Re: [ietf-822] one can re-sign without a permission to re-sign header
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On May 1, 2014, at 12:54 PM, John Levine <johnl@taugh.com> wrote:

>> author's site. That shouldn't require the mailing list to communicate 
>> with the author's site, but it might require the author's site to get 
>> something from the mailing list's site.
> 
> That seems overcomplicated.  Just make the expiration time fairly
> short, since it's a rare mailing list that takes more than a day to do
> its thing.
> 
>>> Perhaps it's time for a more concrete proposal to be written down.
> 
> It occurred to me that there's a very simple way to do this:
> 
> http://datatracker.ietf.org/doc/draft-levine-may-forward/

Dear John,

This scheme permits replay of From header fields with _any_ content irrespective of actual sources.  DKIM-Delegate at least indicates who to trust, irrespective of how the message is identified.  Neither of these schemes will be effective at dealing with spoofing attacks. 

Once one stops ignoring the overhead associated with DKIM and the like, a straight forward authorization scheme becomes far more reasonable from the overhead standpoint and much more effective at mitigating spoofing attacks.  Such a scheme would only come into play for non-aligned messages and does not involve passing around hapless signed tokens as with DKIM-Delegate or DKIM-May-Forward.

Regards,
Douglas Otis