From nobody Tue Dec 8 16:38:11 2015 Return-Path: X-Original-To: tcpinc@ietfa.amsl.com Delivered-To: tcpinc@ietfa.amsl.com Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id B4B6D1B2A62 for ; Tue, 8 Dec 2015 16:38:10 -0800 (PST) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -4.311 X-Spam-Level: X-Spam-Status: No, score=-4.311 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_PASS=-0.001, T_RP_MATCHES_RCVD=-0.01] autolearn=ham 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 kEn6a7g-aNaq for ; Tue, 8 Dec 2015 16:38:09 -0800 (PST) Received: from mailuogwdur.emc.com (mailuogwdur.emc.com [128.221.224.79]) (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 F38B51B2A5F for ; Tue, 8 Dec 2015 16:38:08 -0800 (PST) Received: from maildlpprd54.lss.emc.com (maildlpprd54.lss.emc.com [10.106.48.158]) by mailuogwprd53.lss.emc.com (Sentrion-MTA-4.3.1/Sentrion-MTA-4.3.0) with ESMTP id tB90c71U026683 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Tue, 8 Dec 2015 19:38:07 -0500 X-DKIM: OpenDKIM Filter v2.4.3 mailuogwprd53.lss.emc.com tB90c71U026683 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=emc.com; s=jan2013; t=1449621487; bh=wq39+JAiqaJX8H32Avc+kDtRVsg=; h=From:To:CC:Subject:Date:Message-ID:Content-Type: Content-Transfer-Encoding:MIME-Version; b=Y4tGVkEJJYFGJoowIxRf5msBwYPE1kLAfIgDKFNO4LYJVyVYEBetkIPgDIC2nYHhh aMvXNkABW7raROQGZQezDQPc4lyA+9ws0iIaslYwUv0CKjJ3y30GrDf3JZ1Zel1d4N ogZHggpRA9jI+Dkwd6B3206Xh8nFeem9rSQbftD4= X-DKIM: OpenDKIM Filter v2.4.3 mailuogwprd53.lss.emc.com tB90c71U026683 Received: from mailusrhubprd52.lss.emc.com (mailusrhubprd52.lss.emc.com [10.106.48.25]) by maildlpprd54.lss.emc.com (RSA Interceptor) for ; Tue, 8 Dec 2015 19:37:01 -0500 Received: from mxhub21.corp.emc.com (mxhub21.corp.emc.com [128.222.70.133]) by mailusrhubprd52.lss.emc.com (Sentrion-MTA-4.3.1/Sentrion-MTA-4.3.0) with ESMTP id tB90bmnc026596 (version=TLSv1 cipher=AES128-SHA bits=128 verify=NO) for ; Tue, 8 Dec 2015 19:37:49 -0500 Received: from MXHUB205.corp.emc.com (10.253.68.31) by mxhub21.corp.emc.com (128.222.70.133) with Microsoft SMTP Server (TLS) id 8.3.327.1; Tue, 8 Dec 2015 19:37:47 -0500 Received: from MX104CL02.corp.emc.com ([169.254.8.79]) by MXHUB205.corp.emc.com ([10.253.68.31]) with mapi id 14.03.0266.001; Tue, 8 Dec 2015 19:37:47 -0500 From: "Black, David" To: "tcpinc (tcpinc@ietf.org)" Thread-Topic: TCP-ENO - simultaneous open support - Initial consensus Thread-Index: AdEyGc6r6WwLBA6HRHePBtH7pFX0oA== Date: Wed, 9 Dec 2015 00:37:47 +0000 Message-ID: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.238.45.62] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Sentrion-Hostname: mailusrhubprd52.lss.emc.com X-RSA-Classifications: public Archived-At: Cc: "Black, David" Subject: [tcpinc] TCP-ENO - simultaneous open support - Initial consensus X-BeenThere: tcpinc@ietf.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Discussion list for adding encryption to TCP." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Dec 2015 00:38:10 -0000 With the list discussion having run its course, the WG chairs (David and Kyle in Mirja's absence) have conferred and reviewed the discussion. The original question was: ---- - Should tcpinc support TCP simultaneous open? Yes or No -- If "No," should TCP simultaneous open connection attempts be abandoned or proceed unencrypted? ---- The WG chairs believe that the tcpinc's WG's rough consensus is that: - a) there is no requirement for tcpinc to support all possible TCP-SO cases in all circumstances; but - b) tcpinc should support TCP-SO when it can do so cheaply; and - c) tcpinc setup failures for TCP-SO should result in proceeding unencrypt= ed. Disagreements with this should be surfaced on the list. Two more observations from the WG chairs: - 1) The above, particularly "when it can do so cheaply" in b), is well-aligned with what David Mazieres described as C2: C2. Require application configuration and use one bit to detect incompatible configurations and fall back to unencrypted TCP (the current ENO design, called C2 because it's option #2 in the ENO draft section 6.2). We (WG chairs) prefer "Encourage" to "Require" as the first word above. - 2) Bryan Ford reminds us that attackers will be interested in causing "fail-open" downgrade-attacks that result in no encryption on connections that would otherwise have been encrypted, and points out that making active/passive open look like simultaneous open is a possible attack vector for doing so. We do not believe this to be a fatal flaw in the a/b/c rough consensus approach stated above, but this is a concern that merits careful expert and WG consideration in security analysis of tcpinc. Thanks, --David ---------------------------------------------------- David L. Black, Distinguished Engineer EMC Corporation, 176 South St., Hopkinton, MA=A0 01748 +1 (508) 293-7953=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 FAX: +1 (508) 293-778= 6 david.black@emc.com=A0=A0=A0=A0=A0=A0=A0 Mobile: +1 (978) 394-7754 ----------------------------------------------------