From owner-freebsd-security@FreeBSD.ORG  Wed Dec 10 18:41:07 2003
Return-Path: <owner-freebsd-security@FreeBSD.ORG>
Delivered-To: freebsd-security@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id A6E1D16A4CE
	for <security@freebsd.org>; Wed, 10 Dec 2003 18:41:07 -0800 (PST)
Received: from lariat.org (lariat.org [63.229.157.2])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 4C46A43D13
	for <security@freebsd.org>; Wed, 10 Dec 2003 18:41:06 -0800 (PST)
	(envelope-from brett@lariat.org)
Received: from runaround.lariat.org (IDENT:ppp1000.lariat.org@lariat.org
	[63.229.157.2])	by lariat.org (8.9.3/8.9.3) with ESMTP id TAA24503;
	Wed, 10 Dec 2003 19:40:53 -0700 (MST)
X-message-flag: Warning! Use of Microsoft Outlook renders your system
	susceptible to Internet worms.
Message-Id: <6.0.0.22.2.20031210193940.04f82c20@localhost>
X-Sender: brett@localhost (Unverified)
X-Mailer: QUALCOMM Windows Eudora Version 6.0.0.22
Date: Wed, 10 Dec 2003 19:40:50 -0700
To: Michael Sierchio <kudzu@tenebras.com>
From: Brett Glass <brett@lariat.org>
In-Reply-To: <3FD7C240.4030005@tenebras.com>
References: <6.0.0.22.2.20031210115335.04c2fc50@localhost>
 <20031210093927.70c87960.amonk@gnutec.com>
 <6.0.0.22.2.20031210124332.04e94ac0@localhost>
 <16343.33321.632599.190251@oscar.buszard-welcher.com>
 <6.0.0.22.2.20031210173916.04f57be8@localhost>
 <3FD7C240.4030005@tenebras.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
cc: Kyle Amon <amonk@gnutec.com>
cc: security@freebsd.org
Subject: Re: s/key authentication for Apache on FreeBSD?
X-BeenThere: freebsd-security@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Security issues [members-only posting]
	<freebsd-security.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-security>,
	<mailto:freebsd-security-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-security>
List-Post: <mailto:freebsd-security@freebsd.org>
List-Help: <mailto:freebsd-security-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-security>,
	<mailto:freebsd-security-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 11 Dec 2003 02:41:07 -0000

An excellent reason to use SSL together with S/key.

--Brett

At 06:02 PM 12/10/2003, Michael Sierchio wrote:

>The problem with S/key or OPIE authentication is that it
>is sadly subject to a MITM attack, and relies on
>blind trust in the server.
>
>The challenge is not a random challenge, it is unfortunately
>a sequence number and salt -- if I trick you into typing in
>the one-time password with a lower sequence number than the
>current one you are proper fucked.  I can then generate all of
>the subsequent "one-time" passwords.
>
>If you have a half-authenticated SSL connection, and are
>conducting the exchange over it, then it should be fine.