Re: [Sip] cnonce in RFC 3261

Iñaki Baz Castillo <ibc@aliax.net> Thu, 03 June 2010 15:29 UTC

Return-Path: <ibc@aliax.net>
X-Original-To: sip@core3.amsl.com
Delivered-To: sip@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 4FBC23A69DD for <sip@core3.amsl.com>; Thu, 3 Jun 2010 08:29:13 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: 1.337
X-Spam-Level: *
X-Spam-Status: No, score=1.337 tagged_above=-999 required=5 tests=[BAYES_40=-0.185, FM_FORGED_GMAIL=0.622, J_CHICKENPOX_34=0.6, MIME_8BIT_HEADER=0.3]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id IYQ4hJ5S43AS for <sip@core3.amsl.com>; Thu, 3 Jun 2010 08:29:08 -0700 (PDT)
Received: from mail-pz0-f195.google.com (mail-pz0-f195.google.com [209.85.222.195]) by core3.amsl.com (Postfix) with ESMTP id C05D828C0EF for <sip@ietf.org>; Thu, 3 Jun 2010 08:29:08 -0700 (PDT)
Received: by pzk33 with SMTP id 33so218827pzk.17 for <sip@ietf.org>; Thu, 03 Jun 2010 08:28:52 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.140.247.20 with SMTP id u20mr8351656rvh.122.1275578932474; Thu, 03 Jun 2010 08:28:52 -0700 (PDT)
Received: by 10.140.252.19 with HTTP; Thu, 3 Jun 2010 08:28:52 -0700 (PDT)
In-Reply-To: <345A3596DB43194797927F6ADFBFFFEF02619B68F9@EX41.exchserver.com>
References: <345A3596DB43194797927F6ADFBFFFEF02619B68F9@EX41.exchserver.com>
Date: Thu, 3 Jun 2010 17:28:52 +0200
Message-ID: <AANLkTinfWCU9mpXsZi7g0DCyO3KEQL44vzXGTdtzKpNR@mail.gmail.com>
From: =?UTF-8?Q?I=C3=B1aki_Baz_Castillo?= <ibc@aliax.net>
To: Moloud Mousavi <moloud@blueslice.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Cc: "sip@ietf.org" <sip@ietf.org>
Subject: Re: [Sip] cnonce in RFC 3261
X-BeenThere: sip@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: Session Initiation Protocol <sip.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/sip>, <mailto:sip-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/sip>
List-Post: <mailto:sip@ietf.org>
List-Help: <mailto:sip-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/sip>, <mailto:sip-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 03 Jun 2010 15:29:13 -0000

2010/6/2 Moloud Mousavi <moloud@blueslice.com>om>:
> Hi,
> The Cnonce definition in RFC 3261 is confusing. This is what I found:
>
> cnonce = "cnonce" EQUAL cnonce-value
> cnonce-value = nonce-value
>
> while a bit up an example shows the value of cnonce different than nonce:
>
> nonce="dcd98b7102dd2f0e8b11d0f600bfb0c093",
> uri="sip:bob@biloxi.com",
> qop=auth,
> nc=00000001,
> cnonce="0a4f113b",
> response="6629fae49393a05397450978507c4ef1",

Why do "you" think that cnonce and nonce are different? just because
the different lenght in *your* example? the BNF for nonce-value field
doesn't mandate a strict length for nonce-value, in fact it's just a
queted string:

  nonce-value         =  quoted-string



> I need to calculate the challenge response. I don’t know where to get this
> cnonce from?

Read RFC 2617.




> One more thing: Why are there many names for the same parameter??? Like this
> one: nonce-count = "nc" EQUAL nc-value

Please, read RFC 2617 and 3261 before asking such questions.


-- 
Iñaki Baz Castillo
<ibc@aliax.net>