Re: [Doh] Mozilla's plans re: DoH

Brian Dickson <> Mon, 01 April 2019 20:26 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 61E2112001B for <>; Mon, 1 Apr 2019 13:26:27 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.998
X-Spam-Status: No, score=-1.998 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id 9IO8aab7KY_4 for <>; Mon, 1 Apr 2019 13:26:24 -0700 (PDT)
Received: from ( [IPv6:2607:f8b0:4864:20::82c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id DEAAE12004B for <>; Mon, 1 Apr 2019 13:26:23 -0700 (PDT)
Received: by with SMTP id x12so12553884qts.7 for <>; Mon, 01 Apr 2019 13:26:23 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=3Rm5DMLjCx5GgVmHgCLswj1Ins/I05mhlEA6P1XKyLU=; b=jZO+aRE+254K+umPtUUL4RPd6QyDH466Wo6UCwKXE2TNSLUChhoSW77UHeaHJ1rhrN RbGksJ1g3v2xiP18pvZwwvN6EUtxiP2twzAp+ITWcLitf9msluxVuASJmm1FROXxyzcF ldzlB63qe9PaRHY5+7KqjH69XTywaDNGcR1DmAB3UGX/75yGsW0PsZVbVTukxLqk8ZL8 AHLc40FHDBX7GB+mx97Rww4Po8q/VSqGWPKRkohN1BAu6YujDwmRJIUy8ah2od4bEoGW bsdfaXI4p6dv6gEo+yLuEhozwjxS3tNgTNxrMerbdtJzHT4Hv+6hqfLpzmldUVN2uyNG gGFg==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=3Rm5DMLjCx5GgVmHgCLswj1Ins/I05mhlEA6P1XKyLU=; b=BKJmkarTq+04bwXpBs4aOCc2ekcUZ9TDRINfds+QdDiWnMgM3jlosWBHfGyBykcsDm ZgSQHYWKILcR6zaHeJ7vm82tV+Nz0l1oRYP5H05MrXPTjY1szDNDG574utuc6Ra4r0NZ sUeXSmL5AQgWEGSGxsNVMq7kWJww2uy/j9gNRbTZC00ran3/vWgJhy5qrn7ljFi/Zz2s YhDAnQR9HQ4G1etwuY6rZGSkAZHVpBoHGOQ9KySJqGLiNRkUCq+s26nbwM6os5m616WX Q2/Z8e4QgXaKZ34Ju9xtdDsU30ZVb3mLPfGCrXycDB9icVZU6brNAERJ05aRWiAW5VK2 J2+A==
X-Gm-Message-State: APjAAAUa7G2HzZO8ZDaJ3LwnR7NuInZYcWKMPw6uORYH3zYwPUrXvaP0 DixfAneSUmfzFCAWuF6VQ0Xw9R2uht7/0XE2TLI=
X-Google-Smtp-Source: APXvYqw0lpb/c3QrpZO3E1Hlov+du61V4O++Kp+ayqrPtn9ZOH+U9IPjJSLisMwtFrgRzHD2GdYyvLqbI83IdntvajA=
X-Received: by 2002:ac8:38f5:: with SMTP id g50mr55679764qtc.119.1554150382970; Mon, 01 Apr 2019 13:26:22 -0700 (PDT)
MIME-Version: 1.0
References: <> <>
In-Reply-To: <>
From: Brian Dickson <>
Date: Mon, 1 Apr 2019 13:26:10 -0700
Message-ID: <>
To: "Livingood, Jason" <>
Cc: Eric Rescorla <>, DoH WG <>
Content-Type: multipart/alternative; boundary="0000000000008129bd05857dd5af"
Archived-At: <>
Subject: Re: [Doh] Mozilla's plans re: DoH
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: DNS Over HTTPS <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Mon, 01 Apr 2019 20:26:27 -0000

On Fri, Mar 29, 2019 at 11:31 AM Livingood, Jason <> wrote:

> > [2] Many networks redirect NXDOMAIN to a search/advertising page.
> [JL] This is a reply on this somewhat minor point because NXDOMAIN was
> also raised at the side meeting. I wonder if folks have more specific
> references to networks that are *currently* engaged in NXDOMAIN
> redirection. My sense is that this practice was largely fallen by the
> wayside as a result of being overtaken by the browser-based omnibox
> function that launched several years ago and the resulting change in user
> behavior to just type search terms into the address bar and then click on
> search results. In any case, curious to know if there's a list of ISPs
> currently doing this.
It is probably worth pointing out that, with a very few exceptions in the
CCtld space, that TLDs are DNSSEC signed, and DNSSEC validation can help
prevent NXDOMAIN redirection.
There is still a problematic issue with NSEC3 opt-out. With NSEC or NSEC3
with no opt-out, it is possible to distinguish unsigned delegations from
NXDOMAIN results. When opt-out NSEC3 is used, that is not possible.

This means that in NSEC3 opt-out TLDs, it is technically possible for
NXDOMAIN rewriting by re-purposing the DNSSEC "proof" of NXDOMAIN, into a
DNSSEC "proof" of unsigned delegation.

For TLDs that don't do opt-out, NXDOMAIN rewriting can be blocked by doing
DNSSEC validation.
(This would seem to suggest that having TLDs move away from opt-out would
be in everyone else's interest.)