Re: [quicwg/base-drafts] token-based greasing / initial packet protection (#3166)

Kazuho Oku <> Tue, 05 November 2019 06:58 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id BA66C120020 for <>; Mon, 4 Nov 2019 22:58:50 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -8
X-Spam-Status: No, score=-8 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (1024-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id IpwOvK7bxdC1 for <>; Mon, 4 Nov 2019 22:58:48 -0800 (PST)
Received: from ( []) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 8BF25120013 for <>; Mon, 4 Nov 2019 22:58:48 -0800 (PST)
Received: from ( []) by (Postfix) with ESMTP id AF50E660542 for <>; Mon, 4 Nov 2019 22:58:47 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=pf2014; t=1572937127; bh=5t+yUpyWN0oP/nWBU3R7e9koeP7GGkKijbzkl9w00/Q=; h=Date:From:Reply-To:To:Cc:In-Reply-To:References:Subject:List-ID: List-Archive:List-Post:List-Unsubscribe:From; b=K/gv4tPbUKcTKYub7TDkYfalxKb0pIaRp4s8KoiBqtFg6cxqcJt1/bSoiPOY/UPjx iSwiQJ0evep1p5qn90Uhb4DbvGuBR/oMQQ8nAdLcrFusjo/qMl0EVDLgMNDPQdxXwl nl3hgvUQtIpXRBEvgodrvIaAjRsaJnKL0o3hEJfE=
Date: Mon, 04 Nov 2019 22:58:47 -0800
From: Kazuho Oku <>
Reply-To: quicwg/base-drafts <>
To: quicwg/base-drafts <>
Cc: Subscribed <>
Message-ID: <quicwg/base-drafts/pull/3166/review/>
In-Reply-To: <quicwg/base-drafts/pull/>
References: <quicwg/base-drafts/pull/>
Subject: Re: [quicwg/base-drafts] token-based greasing / initial packet protection (#3166)
Mime-Version: 1.0
Content-Type: multipart/alternative; boundary="--==_mimepart_5dc11da7a0d0f_5ac93f91a36cd9686897b7"; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: list
X-GitHub-Sender: kazuho
X-GitHub-Recipient: quic-issues
X-GitHub-Reason: subscribed
X-Auto-Response-Suppress: All
Archived-At: <>
X-Mailman-Version: 2.1.29
List-Id: Notification list for GitHub issues related to the QUIC WG <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Tue, 05 Nov 2019 06:58:51 -0000

kazuho commented on this pull request.

> +* Initial salt; a 16-byte binary blob that is to be used in place of the initial
+  salt defined in section 5.2 of {{QUIC-TLS}}.
+A server advertises these seeds using a NEW_TOKEN frame {{frame-new-token}}.
+The token MUST permit the server to recover these seeds.  This property can be
+achieved for example by embedding these seeds in the encrypted token.
+For the non-default seeds to work, all the servers within the scope of a
+NEW_TOKEN token are required to have a shared knowledge of those seeds being
+issued and / or how they can be recovered from the tokens. Certain server
+deployments might have difficulty in meeting such a requirement.
+A server (or a set of servers) that cannot satisfy this requirement can stick to
+using the default values by consistently advertising the default version number,
+default initial salt, and a packet type modifier of zero in the NEW_TOKEN frames
+it sends.

Am I correct in assuming that what you are looking for is a clarification that servers can announce a set of alternative versions, each of them tied to a fixed initial salt and packet type modifier?

I think that this is the correct text explaining the multi-CDN use-case, where servers cannot agree on anything.

To paraphrase, we'd be explaining:
1. a server that generates a new initial salt for every connection and embeds it into NEW_TOKEN
2. a server that has a fixed mapping between alternative versions vs. salt (and packet type modifier).
3. a server that does not do greasing at all (multi-CDN).

You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub: