Re: [quicwg/base-drafts] handling of coalesced packets with decryption errors creates DoS opportunity (#2308)

Martin Thomson <> Fri, 01 February 2019 01:51 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 70C641311DD for <>; Thu, 31 Jan 2019 17:51:45 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -12.553
X-Spam-Status: No, score=-12.553 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-4.553, 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_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 gQKaAhUEWRkX for <>; Thu, 31 Jan 2019 17:51:43 -0800 (PST)
Received: from ( []) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 7A62A1311A8 for <>; Thu, 31 Jan 2019 17:51:43 -0800 (PST)
Date: Thu, 31 Jan 2019 17:51:42 -0800
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=pf2014; t=1548985902; bh=/trarzye/awSTdUZUox43upjSkFNPAWhiyZJBfz3aVo=; h=Date:From:Reply-To:To:Cc:In-Reply-To:References:Subject:List-ID: List-Archive:List-Post:List-Unsubscribe:From; b=qtDnFQesngLruKMRoknATJHaXrN0/a6uZBNycOUMtaHqlbbUS6sHngC80Le1d7Otk nNYRdM1uD7k8x8Kq5fMbHTYucJP3OTt50C0pw7ClZ5etsGr50zo98FvFrygTXNo2t5 BoTV2VuHOfGouYClXOGfpU+uuIIfvZIwqBZ0LpGE=
From: Martin Thomson <>
Reply-To: quicwg/base-drafts <>
To: quicwg/base-drafts <>
Cc: Subscribed <>
Message-ID: <quicwg/base-drafts/issues/2308/>
In-Reply-To: <quicwg/base-drafts/issues/>
References: <quicwg/base-drafts/issues/>
Subject: Re: [quicwg/base-drafts] handling of coalesced packets with decryption errors creates DoS opportunity (#2308)
Mime-Version: 1.0
Content-Type: multipart/alternative; boundary="--==_mimepart_5c53a62e72c3_2d53f9fb6cd45c01326a6"; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Precedence: list
X-GitHub-Sender: martinthomson
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: Fri, 01 Feb 2019 01:51:45 -0000

Yes, but @igorlord's point made me reconsider.  I think that the rule would need to be: a) senders MUST NOT coalesce packets of the same encryption level (there is no need to do so, so this is basically a no-op requirement); b) receivers SHOULD/MAY/MUST? discard packets if a packet of the same encryption level was received in the same datagram.  Unfortunately we can't do any more than this because an attacker has complete control over coalescing.

I realize now that this dovetails nicely with the requirement we already added here to require exactly one Retry or Version Negotiation in response to a packet.

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