Re: Packet Number Encryption outside of AEAD

Christian Huitema <huitema@huitema.net> Fri, 27 July 2018 13:43 UTC

Return-Path: <huitema@huitema.net>
X-Original-To: quic@ietfa.amsl.com
Delivered-To: quic@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id A3956130F88 for <quic@ietfa.amsl.com>; Fri, 27 Jul 2018 06:43:40 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.601
X-Spam-Level:
X-Spam-Status: No, score=-2.601 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id joRZw0LWNeSn for <quic@ietfa.amsl.com>; Fri, 27 Jul 2018 06:43:35 -0700 (PDT)
Received: from mx43-out1.antispamcloud.com (mx43-out1.antispamcloud.com [138.201.61.189]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 62411130FC2 for <quic@ietf.org>; Fri, 27 Jul 2018 06:43:33 -0700 (PDT)
Received: from xsmtp04.mail2web.com ([168.144.250.231]) by mx105.antispamcloud.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.89) (envelope-from <huitema@huitema.net>) id 1fj31l-0000jk-9u for quic@ietf.org; Fri, 27 Jul 2018 15:43:30 +0200
Received: from [10.5.2.52] (helo=xmail12.myhosting.com) by xsmtp04.mail2web.com with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.63) (envelope-from <huitema@huitema.net>) id 1fj31g-0004Ka-Vw for quic@ietf.org; Fri, 27 Jul 2018 09:43:25 -0400
Received: (qmail 19053 invoked from network); 27 Jul 2018 13:43:21 -0000
Received: from unknown (HELO [192.168.1.102]) (Authenticated-user:_huitema@huitema.net@[172.56.39.156]) (envelope-sender <huitema@huitema.net>) by xmail12.myhosting.com (qmail-ldap-1.03) with ESMTPA for <quic@ietf.org>; 27 Jul 2018 13:43:21 -0000
To: Kazuho Oku <kazuhooku@gmail.com>, =?UTF-8?Q?Mikkel_Fahn=c3=b8e_J=c3=b8rgensen?= <mikkelfj@gmail.com>
Cc: IETF QUIC WG <quic@ietf.org>
References: <CAN1APdcCdPGVEHJh4FiQBirunHUxY7HV_idYPtyQT09Fe-fSUw@mail.gmail.com> <CANatvzzMhYowiCCCz+_q+zT6LYRjDa9ru33G-tcs44G8r8cBjg@mail.gmail.com>
From: Christian Huitema <huitema@huitema.net>
Openpgp: preference=signencrypt
Autocrypt: addr=huitema@huitema.net; prefer-encrypt=mutual; keydata= xsBNBFIRX8gBCAC26usy/Ya38IqaLBSu33vKD6hP5Yw390XsWLaAZTeQR64OJEkoOdXpvcOS HWfMIlD5s5+oHfLe8jjmErFAXYJ8yytPj1fD2OdSKAe1TccUBiOXT8wdVxSr5d0alExVv/LO I/vA2aU1TwOkVHKSapD7j8/HZBrqIWRrXUSj2f5n9tY2nJzG9KRzSG0giaJWBfUFiGb4lvsy IaCaIU0YpfkDDk6PtK5YYzuCeF0B+O7N9LhDu/foUUc4MNq4K3EKDPb2FL1Hrv0XHpkXeMRZ olpH8SUFUJbmi+zYRuUgcXgMZRmZFL1tu6z9h6gY4/KPyF9aYot6zG28Qk/BFQRtj7V1ABEB AAHNJ0NocmlzdGlhbiBIdWl0ZW1hIDxodWl0ZW1hQGh1aXRlbWEubmV0PsLAeQQTAQIAIwUC UhFfyAIbLwcLCQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJEJNDCbJVyA1yhbYH/1ud6x6m VqGIp0JcZUfSQO8w+TjugqxCyGNn+w/6Qb5O/xENxNQ4HaMQ5uSRK9n8WKKDDRSzwZ4syKKf wbkfj05vgFxrjCynVbm1zs2X2aGXh+PxPL/WHUaxzEP7KjYbLtCUZDRzOOrm+0LMktngT/k3 6+EZoLEM52hwwpIAzJoscyEz7QfqMOZtFm6xQnlvDQeIrHx0KUvwo/vgDLK3SuruG1CSHcR0 D24kEEUa044AIUKBS3b0b8AR7f6mP2NcnLpdsibtpabi9BzqAidcY/EjTaoea46HXALk/eJd 6OLkLE6UQe1PPzQC4jB7rErX2BxnSkHDw50xMgLRcl5/b1bOwE0EUhFfyAEIAKp7Cp8lqKTV CC9QiAf6QTIjW+lie5J44Ad++0k8gRgANZVWubQuCQ71gxDWLtxYfFkEXjG4TXV/MUtnOliG 5rc2E+ih6Dg61Y5PQakm9OwPIsOx+2R+iSW325ngln2UQrVPgloO83QiUoi7mBJPbcHlxkhZ bd3+EjFxSLIQogt29sTcg2oSh4oljUpz5niTt69IOfZx21kf29NfDE+Iw56gfrxI2ywZbu5o G+d0ZSp0lsovygpk4jK04fDTq0vxjEU5HjPcsXC4CSZdq5E2DrF4nOh1UHkHzeaXdYR2Bn1Y wTePfaHBFlvQzI+Li/Q6AD/uxbTM0vIcsUxrv3MNHCUAEQEAAcLBfgQYAQIACQUCUhFfyAIb LgEpCRCTQwmyVcgNcsBdIAQZAQIABgUCUhFfyAAKCRC22tOSFDh1UOlBB/94RsCJepNvmi/c YiNmMnm0mKb6vjv43OsHkqrrCqJSfo95KHyl5Up4JEp8tiJMyYT2mp4IsirZHxz/5lqkw9Az tcGAF3GlFsj++xTyD07DXlNeddwTKlqPRi/b8sppjtWur6Pm+wnAHp0mQ7GidhxHccFCl65w uT7S/ocb1MjrTgnAMiz+x87d48n1UJ7yIdI41Wpg2XFZiA9xPBiDuuoPwFj14/nK0elV5Dvq 4/HVgfurb4+fd74PV/CC/dmd7hg0ZRlgnB5rFUcFO7ywb7/TvICIIaLWcI42OJDSZjZ/MAzz BeXm263lHh+kFxkh2LxEHnQGHCHGpTYyi4Z3dv03HtkH/1SI8joQMQq00Bv+RdEbJXfEExrT u4gtdZAihwvy97OPA2nCdTAHm/phkzryMeOaOztI4PS8u2Ce5lUB6P/HcGtK/038KdX5MYST Fn8KUDt4o29bkv0CUXwDzS3oTzPNtGdryBkRMc9b+yn9+AdwFEH4auhiTQXPMnl0+G3nhKr7 jvzVFJCRif3OAhEm4vmBNDE3uuaXFQnbK56GJrnqVN+KX5Z3M7X3fA8UcVCGOEHXRP/aubiw Ngawj0V9x+43kUapFp+nF69R53UI65YtJ95ec4PTO/Edvap8h1UbdEOc4+TiYwY1TBuIKltY 1cnrjgAWUh/Ucvr++/KbD9tD6C8=
Message-ID: <97ef2887-7e02-7a57-efe9-f6e54dcbf0dc@huitema.net>
Date: Fri, 27 Jul 2018 06:43:22 -0700
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1
MIME-Version: 1.0
In-Reply-To: <CANatvzzMhYowiCCCz+_q+zT6LYRjDa9ru33G-tcs44G8r8cBjg@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Content-Language: en-US
Subject: Re: Packet Number Encryption outside of AEAD
X-Originating-IP: 168.144.250.231
X-AntiSpamCloud-Domain: xsmtpout.mail2web.com
X-AntiSpamCloud-Username: 168.144.250.0/24
Authentication-Results: antispamcloud.com; auth=pass smtp.auth=168.144.250.0/24@xsmtpout.mail2web.com
X-AntiSpamCloud-Outgoing-Class: unsure
X-AntiSpamCloud-Outgoing-Evidence: Combined (0.11)
X-Recommended-Action: accept
X-Filter-ID: EX5BVjFpneJeBchSMxfU5sAWxx+raDIKj4lxLTm7F3N602E9L7XzfQH6nu9C/Fh9KJzpNe6xgvOx q3u0UDjvO37pNwwF1lRXh5rzvPzo9Jts1ujulqUFmMITHM77eiViSSeRRXp+kIstRaiReIekXs7i TvJ2/ZGzVWB9scFAaCdIFaUvXN+CI+RGy3Me16pB1VzUjpi3KNxdQZ39cmOPHk5EpHPznVavQp4h 1cyzxbQFXqQgkkYk8mNUb0+uxPxhiSGt4Ko2sv7hY6P0Yu3OA+AIcPc2JG++Fh0y/kogNkMJ0464 etNXHOU+5Kb0QuG3bATPP9eeLWC5kDweN7crsXBXvrLBlKCVRjjdPbjQ4HmidG0pg2HLuLsP3mPp isElTs5Ex5aNZlcgVQFtAhrEij3dKxLhoxcmaInYbR5vlqETd+klAX+KFYkIxu6zxdn+X2XX9bIs GDSYq5OAASmskVIcMSgqtcKbU9La+AHiCFB9vuYMeDoXsMJDD9CZFW2Drvl3AsHuisl/RSyh5DLe 1OidX4Ts4xdG+C13IyWeZaKFx/oZIYfnv6X4HqmwQedqF8FcHzzV3acxBudgYcInb9GkghycT1df ko8m/t56ZgyZ4+t4LK79cWIqQA4tGr3po0jfgLl+Ahd0TIbt0Zij6hgeJ07QR0GiieIKGR3KfdmQ xACKGgjW6av7lJfpYBfZN1zg8T9ahw4hquQDupK1jlwBl1z1+w2zS/h3e6UiVRcINLwG6Bo+JaQM +C8JASYyS//k0VHDkAzPFlaOxUvkWmeqA47D/juB1cx4exzYk7wfjirBnMSvLt+oZCsKZvqt647l NwN4qOsSZg+fYhVZG9EQ9b9YI+9ZsqMLtlmzzH7VwaDsyRiTeu4Ip+KAECko9HdE0Smt1e6HZuGs N7RwePAFMvX7q8M4x6bP/gjzw0OFbIWNJOiaifOc2xlkb46Pa4K5MPGI7fF8+j7E9IwdcQR2aish SbQcCCOvcJLn8v/2OKHH5lr9xXvSM4nM3avg
X-Report-Abuse-To: spam@quarantine6.antispamcloud.com
Archived-At: <https://mailarchive.ietf.org/arch/msg/quic/EvL-1fgtV3ID9wI2SJ4indUUwBs>
X-BeenThere: quic@ietf.org
X-Mailman-Version: 2.1.27
Precedence: list
List-Id: Main mailing list of the IETF QUIC working group <quic.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/quic>, <mailto:quic-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/quic/>
List-Post: <mailto:quic@ietf.org>
List-Help: <mailto:quic-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/quic>, <mailto:quic-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 27 Jul 2018 13:43:48 -0000


On 7/26/2018 9:14 PM, Kazuho Oku wrote:
> Consider the case where a sender encodes a packet number using 4
> octets even when just using 1 octet is enough.
>
> An on-path attacker rewrites the packet by applying XOR 0x80 to the
> first octet of the encrypted PN, and trimming the latter three octets
> of the encrypted PN.
That attack does not work, because the encoding of the PN is big-endian.
The actual packet number is in the fourth octet. Or rather, it only
works in the special case where the PN is 0.

-- Christian Huitema