Re: [DNSOP] extension of DoH to authoritative servers

Stephane Bortzmeyer <bortzmeyer@nic.fr> Wed, 13 February 2019 14:23 UTC

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Date: Wed, 13 Feb 2019 15:22:56 +0100
From: Stephane Bortzmeyer <bortzmeyer@nic.fr>
To: Paul Vixie <paul@redbarn.org>
Cc: David Conrad <drc@virtualized.org>, dnsop <dnsop@ietf.org>
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Subject: Re: [DNSOP] extension of DoH to authoritative servers
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On Tue, Feb 12, 2019 at 10:34:19AM -0800,
 Paul Vixie <paul@redbarn.org>; wrote 
 a message of 15 lines which said:

> > How can you be sure folks on your network aren’t already tunneling
> > their evil deeds through HTTPS?
> 
> netflow. such traffic _looks_ abnormal.
> 
> the deliberate design premise of DoH is that it look normal.

If TLS does its job, how can you make the difference between DoH and
EvilNonStandardNameResolutionProtocolRunningOverTLS?

There are some metadata that can help (such as sizes and timing) but
IETF continue to develop tricks like padding to make them as
inefficient as possible.

I would really like to know how you could detect
EvilNonStandardNameResolutionProtocolRunningOverTLS but not DoH?