Re: SMTP RFC: "MUST NOT" change or delete Received header

Dave Crocker <dhc@dcrocker.net> Mon, 31 March 2014 02:16 UTC

Return-Path: <dhc@dcrocker.net>
X-Original-To: ietf@ietfa.amsl.com
Delivered-To: ietf@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 4467F1A08E9 for <ietf@ietfa.amsl.com>; Sun, 30 Mar 2014 19:16:00 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.2
X-Spam-Level:
X-Spam-Status: No, score=-4.2 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3] 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 YiSV_9J8VGxf for <ietf@ietfa.amsl.com>; Sun, 30 Mar 2014 19:15:57 -0700 (PDT)
Received: from sbh17.songbird.com (sbh17.songbird.com [72.52.113.17]) by ietfa.amsl.com (Postfix) with ESMTP id E13611A0412 for <ietf@ietf.org>; Sun, 30 Mar 2014 19:15:57 -0700 (PDT)
Received: from [192.168.1.66] (76-218-8-156.lightspeed.sntcca.sbcglobal.net [76.218.8.156]) (authenticated bits=0) by sbh17.songbird.com (8.13.8/8.13.8) with ESMTP id s2V2Fpf8002593 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Sun, 30 Mar 2014 19:15:54 -0700
Message-ID: <5338CF6A.20304@dcrocker.net>
Date: Sun, 30 Mar 2014 19:14:02 -0700
From: Dave Crocker <dhc@dcrocker.net>
Organization: Brandenburg InternetWorking
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0
MIME-Version: 1.0
To: Ted Lemon <ted.lemon@nominum.com>
Subject: Re: SMTP RFC: "MUST NOT" change or delete Received header
References: <20140330151432.2721.qmail@joyce.lan> <A3DE810811F791EDC532BDFB@JcK-HP8200.jck.com> <CAMm+LwjrY44GhdMCkqEL_YssNNR=isx-cSQ6KZH-1bkXO7RJWQ@mail.gmail.com> <86005B600BB2261DFDEE715B@JcK-HP8200.jck.com> <9EC12CC9-81CD-4C3E-ADD1-283615767B17@nominum.com>
In-Reply-To: <9EC12CC9-81CD-4C3E-ADD1-283615767B17@nominum.com>
Content-Type: text/plain; charset="ISO-8859-1"; format="flowed"
Content-Transfer-Encoding: 7bit
X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0 (sbh17.songbird.com [72.52.113.66]); Sun, 30 Mar 2014 19:15:55 -0700 (PDT)
Archived-At: http://mailarchive.ietf.org/arch/msg/ietf/UNVUGOzdPSKmY7FDsm8joG0uYkk
Cc: IETF Discussion Mailing List <ietf@ietf.org>
X-BeenThere: ietf@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
Reply-To: dcrocker@bbiw.net
List-Id: IETF-Discussion <ietf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ietf>, <mailto:ietf-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/ietf/>
List-Post: <mailto:ietf@ietf.org>
List-Help: <mailto:ietf-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ietf>, <mailto:ietf-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 31 Mar 2014 02:16:00 -0000

On 3/30/2014 5:38 PM, Ted Lemon wrote:
> On Mar 30, 2014, at 6:44 PM, John C Klensin <john-ietf@jck.com> wrote:
>> Whether one accepts it or not, "been here already" tests are not
>> about debugging.  They are about loop detection and DoS attacks.
>
> Are there MTAs that make use of the Received: header for loop detection?


MMDF had it, probably from the early 1980s, but certainly sometime 
during the 80s.

I have a vague recollection of adding it to the code, though that could 
be an invented memory.  The Received header field was not in RFC 733, 
and was standardized in late 1982 (RFC 822), just before I stopped doing 
MMDF work.

More likely, it was added by the folk who did the follow-on work for 
MMDF II, but still probably early/mid 1980s.


Back then, passing through the same host more than a couple of times 
would be a good indication of looping.

d/
-- 
Dave Crocker
Brandenburg InternetWorking
bbiw.net