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Re: [dmarc-ietf] indeterminisim of ARC-Seal b= value

"Murray S. Kucherawy" <superuser@gmail.com> Thu, 30 March 2017 08:54 UTC

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From: "Murray S. Kucherawy" <superuser@gmail.com>
Date: Thu, 30 Mar 2017 03:54:01 -0500
Message-ID: <CAL0qLwa7+uo++C0evi+DOUxq-omD4PiWqU3dMXj2kBHRpmyfPg@mail.gmail.com>
To: Brandon Long <blong@google.com>
Cc: Peter Goldstein <peter@valimail.com>, "dmarc@ietf.org" <dmarc@ietf.org>, John R Levine <johnl@taugh.com>, Gene Shuman <gene@valimail.com>
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Subject: Re: [dmarc-ietf] indeterminisim of ARC-Seal b= value
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On Mon, Mar 27, 2017 at 1:06 PM, Brandon Long <blong@google.com> wrote:

> What does validating the exact signature generated benefit us over just
> verifying that the signature verifies?
>

The most obvious benefit I can think of is that the output of signing is
entirely deterministic.  You could test it with strcmp() on a disconnected
computer, rather than invoking a complete ARC verifier that might need DNS
and would have to invoke crypto functions.

-MSK

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