Re: [TLS] WGLC for draft-ietf-tls-exported-authenticator
Eric Rescorla <ekr@rtfm.com> Thu, 10 May 2018 04:07 UTC
Return-Path: <ekr@rtfm.com>
X-Original-To: tls@ietfa.amsl.com
Delivered-To: tls@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 5E8CC12E8D4 for <tls@ietfa.amsl.com>; Wed, 9 May 2018 21:07:26 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.908
X-Spam-Level:
X-Spam-Status: No, score=-1.908 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, T_DKIMWL_WL_MED=-0.01, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=rtfm-com.20150623.gappssmtp.com
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 bVzT_7VQiZXm for <tls@ietfa.amsl.com>; Wed, 9 May 2018 21:07:24 -0700 (PDT)
Received: from mail-ot0-x230.google.com (mail-ot0-x230.google.com [IPv6:2607:f8b0:4003:c0f::230]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 07BF812E8D7 for <tls@ietf.org>; Wed, 9 May 2018 21:07:24 -0700 (PDT)
Received: by mail-ot0-x230.google.com with SMTP id y10-v6so821270otg.10 for <tls@ietf.org>; Wed, 09 May 2018 21:07:24 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rtfm-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=lq6Kq1mhe5leVWSNQ/uxMa/H8d0iC/iK+b64nNUEjBE=; b=kbGtbkgP38HhsOipISEdJ0plvO3yLGhZcDL6RRY7Du5xeJPpCb7Cc/O963s9Nruj0i nfR697lCFDDH2IOsInClj1KlDhfZz4/rMx6Nt/47Pi3XBaIHwfhrRrzL8M92y17QAyhs T9DZU3N3rv1G63tcoJHGVcgjDJDXmy2qcjupTyvGBeNxzUP4agiq1cNu1QupX9qTLtoO 3j4dCpKOf6jRXRsB1pgtcyJ9HnvZrGUlFhipivQptdru3BL/cOZLD8mCbXvdrxoOL4A9 tyNlVG2tmlpZyvO717b2yxBwHD1uQnOE+ggHbnZYzEUdNlPpIjACqWAaV7C0c763Gjkr P7EA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=lq6Kq1mhe5leVWSNQ/uxMa/H8d0iC/iK+b64nNUEjBE=; b=Dw2el+w4+2s2CtzqzdAief0GIWH+u/cqFC64oe6ae0AKHPYEcM5iIMFlBABbDjViIr u0LDlRJn8K83nykzEwxVeIfONyGdm9n7PxEIP2aofxOkSzuvUfH5Hu+sgAnrp928GVZj 7nH4J7y5j/eLJvJwCCEBNBlDqfqivfu0AvYnpWtnP31SNlrHhQ8ONoszGAflyTMkR7Xh MKC3woUMuYEQW+7rHDfhhsWs4QtFBFaX3DDagGLj+JZeFJYjeWsAgQjJJgQRuIqTGNPu CbLWxx2ySJ8qsSeAMpY9UwWZnA3xgeo3YAPlYZC9zYYFrziCknQQun73SxiWPlPBKUWe vK7g==
X-Gm-Message-State: ALKqPwecgK8h8e/JDy16fB6QeIy1e2dPO15NRaGK2l3FOQ5Ic8NTXA2j bnupcFOtJkF2yx8o2zbSlWHjXCd1ZpkppZohbkU5VQ==
X-Google-Smtp-Source: AB8JxZpfDvEur+OWW8c63HE44rd3+22SXV9HYZq6vfd+uyRD/+oYUR4T0qyaFT8qrozK700IFNJ5tMAoux3+6vw/c3w=
X-Received: by 2002:a9d:3694:: with SMTP id h20-v6mr7577235otc.176.1525925243429; Wed, 09 May 2018 21:07:23 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.201.118.130 with HTTP; Wed, 9 May 2018 21:06:42 -0700 (PDT)
In-Reply-To: <CABkgnnXyqzDn4cVmZA87O4+RsoLEQXP5R+BcDMsuGaLQHQme_w@mail.gmail.com>
References: <4E347898-C787-468C-8514-30564D059378@sn3rd.com> <96B30D45-BAA9-4798-B222-F7890157A434@nerd.ninja> <20180504214834.GS5742@akamai.com> <50E87E1B-A2DE-4E0A-B851-B83D2AA9320D@nerd.ninja> <CABcZeBPp_ibhmKJfLvqGMJj4sz6u4bC1-2ncJZ3zbGVCyEHCPw@mail.gmail.com> <EFDFA96E-ED01-42AC-BA8A-7844974FDFF9@nerd.ninja> <726B4BF1-79AA-494E-9852-DC3682E80E3A@nerd.ninja> <CABkgnnWmGYZ8V1a0TJs3eCcDA=sxgyCT0MPUfQdLOR-jVf1kfg@mail.gmail.com> <B62611A2-D9F0-4752-AA90-46974EA47517@nerd.ninja> <CABkgnnV1hp7ueCSPJ9aM0a9B2KN-Uawd_UWwCRaZr=zRZgTRUg@mail.gmail.com> <CABcZeBMXrXxEjB=2FVRtN+Gs5jhkpNETp2RtDb2G7V5ZhemgmA@mail.gmail.com> <CABkgnnXyqzDn4cVmZA87O4+RsoLEQXP5R+BcDMsuGaLQHQme_w@mail.gmail.com>
From: Eric Rescorla <ekr@rtfm.com>
Date: Wed, 09 May 2018 21:06:42 -0700
Message-ID: <CABcZeBO_wgQPd+3m1+sc3DWfs4LTTjek4+bPyE=C0=kPOLVG7g@mail.gmail.com>
To: Martin Thomson <martin.thomson@gmail.com>
Cc: R du Toit <r@nerd.ninja>, "<tls@ietf.org>" <tls@ietf.org>
Content-Type: multipart/alternative; boundary="00000000000016b93e056bd228be"
Archived-At: <https://mailarchive.ietf.org/arch/msg/tls/MMiHSouffsQlb0VhaSizZ6bo02w>
Subject: Re: [TLS] WGLC for draft-ietf-tls-exported-authenticator
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: "This is the mailing list for the Transport Layer Security working group of the IETF." <tls.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tls>, <mailto:tls-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tls/>
List-Post: <mailto:tls@ietf.org>
List-Help: <mailto:tls-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tls>, <mailto:tls-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 10 May 2018 04:07:26 -0000
On Wed, May 9, 2018 at 7:15 PM, Martin Thomson <martin.thomson@gmail.com> wrote: > I'm not that concerned about this, though I will concede that it's worth > pointing out. > > Failing to validate a secondary certificate for a server shouldn't be cause > for terminating an otherwise usable connection. To be clear: it's not failing to validate the *certificate* it's that the CertificateVerify to validate. This should ordinarily never happen, so I definitely think we should call that out. -Ekr The same goes for clients > that authenticate using this. As long as users of exported authenticators > are aware of this, then they can design for it. > > If those users wanted confirmation, then we could provide a > confirmation-of-mechanism-viability in the application layer. That could > just be by including a value derived from the exporter in the negotiation. > > In h2, we could do as much as 4 octets of confirmation for cheap, and maybe > we should. > https://github.com/httpwg/http-extensions/issues/617 > On Wed, May 9, 2018 at 11:28 PM Eric Rescorla <ekr@rtfm.com> wrote: > > > Regardless of where it goes in the document, I think there's a real > deployment > > consideration here: if you run this mechanism through a conventional MITM > > proxy, what will happen will be that the secondary cert auth will appear > to just > > fail with a bogus signature. If clients respond to that by terminating > the connection, > > then we're going to be in pretty bad shape [0]. So I think we either > need: > > > 1. To negotiate this with an extension > > 2. To tell people not to treat signature failures as a hard failure. > > 3. To have some way to indicate that there was a MITM on-path (e.g., have > the > > application level mechanism include some separate value that's tied > to > > the channel that lets the endpoints detect when its two separate > channels). > > > -Ekr > > > > [0] Note that this also applies to post-handshake authentication, but > that's negotiated > > with an extension, so S 9.3 applies. > > > > On Wed, May 9, 2018 at 12:39 AM, Martin Thomson < > martin.thomson@gmail.com> > wrote: > > >> This isn't really a security consideration though, it's a truism. A > MitM > >> can break things that depend on end-to-end integrity of the connection. > >> On Wed, May 9, 2018 at 11:25 AM Roelof duToit <r@nerd.ninja> wrote: > > >> > If the use of the mechanism is not negotiated on the TLS level then I > >> would appreciate it if the “Security Considerations” section of the > draft > >> could be amended to include a paragraph that warns potential > implementors > >> that protocol-agnostic middleboxes will break the mechanism without any > >> clear failure indicators. > > >> > > On May 8, 2018, at 8:13 PM, Martin Thomson < > martin.thomson@gmail.com> > >> wrote: > >> > > > >> > > On Wed, May 9, 2018 at 2:20 AM Roelof duToit <r@nerd.ninja> wrote: > >> > > > >> > >> I understand that there is not really anything to negotiate per se, > but > >> > > would it not be prudent to add a TLS extension to negotiate support > for > >> > > exported-authenticator in the TLS layer prior to using it in the > >> > > application layer? > >> > > > >> > > We don't signal the potential need for exporters. I see no reason > to > >> > > signal this either. Any signaling necessary really belongs at the > >> higher > >> > > layer. >
- [TLS] WGLC for draft-ietf-tls-exported-authentica… Sean Turner
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Sean Turner
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Sean Turner
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Nick Sullivan
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Martin Thomson
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Nikos Mavrogiannopoulos
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Tim Hollebeek
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Jonathan Hoyland
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Roelof duToit
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Christopher Wood
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Benjamin Kaduk
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Benjamin Kaduk
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Roelof duToit
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Eric Rescorla
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Roelof duToit
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Roelof duToit
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Mike Bishop
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Martin Thomson
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Roelof duToit
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Martin Thomson
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Roelof duToit
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Salz, Rich
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Eric Rescorla
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Martin Thomson
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Eric Rescorla
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Nick Sullivan
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Martin Thomson
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Nick Sullivan
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Martin Thomson
- Re: [TLS] WGLC for draft-ietf-tls-exported-authen… Nick Sullivan