Re: Sections 3.3.2 and 3.3.3 allow bogus Content-Length?
"Adrien de Croy" <adrien@qbik.com> Tue, 14 February 2017 23:21 UTC
Return-Path: <ietf-http-wg-request+bounce-httpbisa-archive-bis2juki=lists.ie@listhub.w3.org>
X-Original-To: ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com
Delivered-To: ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 915DF12953F for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Tue, 14 Feb 2017 15:21:30 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -6.902
X-Spam-Level:
X-Spam-Status: No, score=-6.902 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.001, RCVD_IN_DNSWL_HI=-5, RP_MATCHES_RCVD=-0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
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 uCZLpanRzhon for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Tue, 14 Feb 2017 15:21:28 -0800 (PST)
Received: from frink.w3.org (frink.w3.org [128.30.52.56]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 90EEB12958A for <httpbisa-archive-bis2Juki@lists.ietf.org>; Tue, 14 Feb 2017 15:21:28 -0800 (PST)
Received: from lists by frink.w3.org with local (Exim 4.80) (envelope-from <ietf-http-wg-request@listhub.w3.org>) id 1cdmNG-0005ns-Ns for ietf-http-wg-dist@listhub.w3.org; Tue, 14 Feb 2017 23:19:06 +0000
Resent-Date: Tue, 14 Feb 2017 23:19:06 +0000
Resent-Message-Id: <E1cdmNG-0005ns-Ns@frink.w3.org>
Received: from mimas.w3.org ([128.30.52.79]) by frink.w3.org with esmtps (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from <adrien@qbik.com>) id 1cdmNC-0005mT-Uu for ietf-http-wg@listhub.w3.org; Tue, 14 Feb 2017 23:19:02 +0000
Received: from smtp.qbik.com ([122.56.26.1]) by mimas.w3.org with esmtps (TLS1.2:ECDHE_RSA_ARCFOUR_128_SHA1:128) (Exim 4.84_2) (envelope-from <adrien@qbik.com>) id 1cdmN5-0001Da-EQ for ietf-http-wg@w3.org; Tue, 14 Feb 2017 23:18:57 +0000
Received: From [192.168.1.146] (unverified [192.168.1.146]) by SMTP Server [192.168.1.3] (WinGate SMTP Receiver v9.0.4 (Build 5915)) with SMTP id <0000964558@smtp.qbik.com>; Wed, 15 Feb 2017 12:18:24 +1300
From: Adrien de Croy <adrien@qbik.com>
To: Alex Rousskov <rousskov@measurement-factory.com>, "ietf-http-wg@w3.org" <ietf-http-wg@w3.org>
Date: Tue, 14 Feb 2017 23:18:24 +0000
Message-Id: <em95b13204-3a33-4bd5-81d2-791e809b9cd2@bodybag>
In-Reply-To: <874938e6-2153-e02a-ab0e-814f468c58f8@measurement-factory.com>
References: <emdcb96fc0-0d2f-436c-9f1f-05beffe7593e@bodybag> <e01c4945-1116-d258-7004-ea917843bf3d@ninenines.eu> <ema747b801-6dcc-4b2d-ac95-9a027e10c0b4@bodybag> <7874c62b-c6a0-5d84-8115-20016b45118a@measurement-factory.com> <em541e3407-4e99-468e-a1e7-85a7bf074bdd@bodybag> <874938e6-2153-e02a-ab0e-814f468c58f8@measurement-factory.com>
Reply-To: Adrien de Croy <adrien@qbik.com>
User-Agent: eM_Client/7.0.27943.0
Mime-Version: 1.0
Content-Type: text/plain; format="flowed"; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
Received-SPF: pass client-ip=122.56.26.1; envelope-from=adrien@qbik.com; helo=smtp.qbik.com
X-W3C-Hub-Spam-Status: No, score=-4.6
X-W3C-Hub-Spam-Report: AWL=-0.709, BAYES_00=-1.9, RP_MATCHES_RCVD=-0.001, SPF_PASS=-0.001, W3C_AA=-1, W3C_WL=-1
X-W3C-Scan-Sig: mimas.w3.org 1cdmN5-0001Da-EQ 06086247bc288157ce360c8aa226a0a5
X-Original-To: ietf-http-wg@w3.org
Subject: Re: Sections 3.3.2 and 3.3.3 allow bogus Content-Length?
Archived-At: <http://www.w3.org/mid/em95b13204-3a33-4bd5-81d2-791e809b9cd2@bodybag>
Resent-From: ietf-http-wg@w3.org
X-Mailing-List: <ietf-http-wg@w3.org> archive/latest/33507
X-Loop: ietf-http-wg@w3.org
Resent-Sender: ietf-http-wg-request@w3.org
Precedence: list
List-Id: <ietf-http-wg.w3.org>
List-Help: <http://www.w3.org/Mail/>
List-Post: <mailto:ietf-http-wg@w3.org>
List-Unsubscribe: <mailto:ietf-http-wg-request@w3.org?subject=unsubscribe>
I disagree Content-Length the concept is indeed the content length. Content-Length the header is a _header_ which _represents_ Content-Length the concept. It's a promise made by the sender that the sender will send that many bytes of body. The only true size of a body is what you obtain by counting its bytes. The Content-Length header is not part of that body, it's sent in the headers, we parse it, convert the string to a number. Yet we have no rule stating it must be consistent with what is sent. I think we could be a little less timid about this and call it like it is. Adrien ------ Original Message ------ From: "Alex Rousskov" <rousskov@measurement-factory.com> To: "Adrien de Croy" <adrien@qbik.com>; "ietf-http-wg@w3.org" <ietf-http-wg@w3.org> Sent: 15/02/2017 12:13:56 PM Subject: Re: Sections 3.3.2 and 3.3.3 allow bogus Content-Length? >On 02/14/2017 03:54 PM, Adrien de Croy wrote: >> I have no problem with the concept of adding a rule that states that >> >> objects labelled as weighing 5T MUST weigh 5T or the label is >> incorrect/invalid. > >Thinking of Content-Length as a packaging label gets you into the very >trap you want to escape: Yes, rules for labeling accuracy would be >fine, >but Content-Length (in relevant contexts) is _not_ a label! >Content-Length does not merely document weight that you can >independently measure and validate. Content-Length _is_ weight. > >Alex. > > > >> ------ Original Message ------ >> From: "Alex Rousskov" <rousskov@measurement-factory.com> >> To: "ietf-http-wg@w3.org" <ietf-http-wg@w3.org> >> Cc: "Adrien de Croy" <adrien@qbik.com> >> Sent: 15/02/2017 11:38:17 AM >> Subject: Re: Sections 3.3.2 and 3.3.3 allow bogus Content-Length? >> >>> On 02/14/2017 02:12 PM, Adrien de Croy wrote: >>> >>>> I did quote that section, but it doesn't define what an invalid >>>>C-L is. >>> >>> The term "valid" in that section means "syntactically correct". 123 >>>is >>> valid. 0x123 is not. 0123 is valid unless the recipient is paranoid. >>> >>> >>>> Nowhere does it explicitly state that C-L value must equal the >>>>body >>>> size >>>> in order to be valid. >>> >>> You are correct. The message framing rules (3.3.3.1-5) establish >>>that >>> C-L value and body length are the same concept (for the applicable >>>cases >>> where C-L value is used for framing and only for those cases). >>> >>> In other words, one should not add a "C-L value MUST match the body >>> length" or "the body length MUST match the C-L value" rule because >>>the >>> body length _is_ the C-L value (for the applicable cases). Adding >>>such a >>> rule would be like saying "an object with a weight of 5 tons MUST >>>weigh >>> 5 tons". >>> >>> >>> HTH, >>> >>> Alex. >>> >>> >>>> ------ Original Message ------ >>>> From: "Loïc Hoguin" <essen@ninenines.eu> >>>> To: "Adrien de Croy" <adrien@qbik.com>; "ietf-http-wg@w3.org" >>>> <ietf-http-wg@w3.org> >>>> Sent: 15/02/2017 10:05:46 AM >>>> Subject: Re: Sections 3.3.2 and 3.3.3 allow bogus Content-Length? >>>> >>>>> On 02/14/2017 09:49 PM, Adrien de Croy wrote: >>>>>> >>>>>> The language in RFC 7230 section 3.3.2 is extremely non-commital >>>>>> about >>>>>> whether Content-Length needs to be correct or not. >>>>>> >>>>>> I'm currently having a dispute about this with someone who >>>>>>quoted >>>>>> these >>>>>> sections at me as being proof that you can use any value for C-L >>>>>> regardless of the body length. >>>>>> >>>>>> I think it could be a lot more forcefully written >>>>>> >>>>>> Or is the person correct and we don't need to have C-L match the >>>>>>body >>>>>> length? >>>>> >>>>> It sounds pretty explicit to me: >>>>> >>>>> 4. If a message is received without Transfer-Encoding and >>>>>with >>>>> either multiple Content-Length header fields having >>>>>differing >>>>> field-values or a single Content-Length header field >>>>>having an >>>>> invalid value, then the message framing is invalid and the >>>>> recipient MUST treat it as an unrecoverable error. If >>>>>this >>>>> is a >>>>> request message, the server MUST respond with a 400 (Bad >>>>> Request) >>>>> status code and then close the connection. >>>>> >>>>> If it's both invalid and required for handling the request, send >>>>>a 400 >>>>> and close the connection. >>>>> >>>>> I suppose the spec allows you to have an invalid Content-Length >>>>>if and >>>>> only if the request also has a Transfer-Encoding header, however: >>>>> >>>>> If a message is received with both a Transfer-Encoding and >>>>>a >>>>> Content-Length header field, the Transfer-Encoding >>>>>overrides >>>>> the >>>>> Content-Length. Such a message might indicate an attempt >>>>>to >>>>> perform request smuggling (Section 9.5) or response >>>>>splitting >>>>> (Section 9.4) and ought to be handled as an error. >>>>> >>>>> So sending a 400 and closing does not sound crazy even in that >>>>>case, >>>>> despite the spec not requiring it. >>>>> >>>>> -- Loïc Hoguin >>>>> https://ninenines.eu >>>> >>> >> >
- Sections 3.3.2 and 3.3.3 allow bogus Content-Leng… Adrien de Croy
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Loïc Hoguin
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Poul-Henning Kamp
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Adrien de Croy
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Adrien de Croy
- RE: Sections 3.3.2 and 3.3.3 allow bogus Content-… Mike Bishop
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Matthew Kerwin
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Jason T. Greene
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Jacob Champion
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Poul-Henning Kamp
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Daniel Stenberg
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Willy Tarreau
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Adrien de Croy
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Adrien de Croy
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Alex Rousskov
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Jacob Champion
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Adrien de Croy
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Alex Rousskov
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Adrien de Croy
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Jacob Champion
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Adrien de Croy
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Adrien de Croy
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Alex Rousskov
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Adrien de Croy
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Alex Rousskov
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Matthew Kerwin
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Adrien de Croy
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Alex Rousskov
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Mark Nottingham
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Willy Tarreau
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Poul-Henning Kamp
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Cory Benfield
- Re: Sections 3.3.2 and 3.3.3 allow bogus Content-… Patrick McManus