Re: [DNSOP] Resolver behaviour with multiple trust anchors

Tony Finch <dot@dotat.at> Thu, 02 November 2017 15:53 UTC

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Date: Thu, 2 Nov 2017 15:53:41 +0000
From: Tony Finch <dot@dotat.at>
To: Paul Hoffman <paul.hoffman@vpnc.org>
cc: Bob Harold <rharolde@umich.edu>, "dnsop@ietf.org" <dnsop@ietf.org>
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Subject: Re: [DNSOP] Resolver behaviour with multiple trust anchors
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Paul Hoffman <paul.hoffman@vpnc.org>; wrote:
> On 2 Nov 2017, at 8:04, Bob Harold wrote:
>
> > I generally agree with you, but wonder if there is a performance penalty to
> > searching every possible path before failing.  Is that a reasonable concern?
>
> These are reasonable questions, ones that were actively discussed in the PKIX
> world 20+ years ago. The consensus conclusion was that any performance penalty
> was worth the consistency of answers, since the relying part (the stub
> resolver in our case) had no control over the order of evaluation.

It's worth noting that the PKIX chain of trust is a directed graph whereas
the DNS is a tree, and trees are a lot easier to follow. (No loops etc.)

Tony.
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