Re: [DNSOP] Validating responses when following unsigned CNAME chains...

Brian Somers <bsomers@opendns.com> Thu, 30 April 2020 16:00 UTC

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From: Brian Somers <bsomers@opendns.com>
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Date: Thu, 30 Apr 2020 09:00:00 -0700
Cc: Brian Somers <bsomers@opendns.com>, Shumon Huque <shuque@gmail.com>, "dnsop@ietf.org WG" <dnsop@ietf.org>, Michael StJohns <msj@nthpermutation.com>
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To: Ted Lemon <mellon@fugue.com>
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Subject: Re: [DNSOP] Validating responses when following unsigned CNAME chains...
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On Apr 30, 2020, at 8:17 AM, Ted Lemon <mellon@fugue.com> wrote:
> 
> On Apr 29, 2020, at 11:38 PM, Brian Somers <bsomers@opendns.com> wrote:
>> Furthermore, the CNAME alias RRset must be validated unless the CD bit is set.
>> A validating resolver MUST validate and can only return RRsets if they are proven
>> to be either insecure or secure.  If the aliased RRset is bogus, the answer is
>> SERVFAIL.
> 
> Ah. I like this answer. Is there a place where this is stated in the RFC that we can point to?
> 

I would say RFC 4035 sections 4.2 and 4.3 say this.  Section 5.5 re-iterates that
SERVFAIL should be sent if signatures don’t validate.

—
Brian