W3C home > Mailing lists > Public > ietf-http-wg-old@w3.org > January to April 1997

Re: Comments on the new cookie draft

From: Foteos Macrides <MACRIDES@sci.wfbr.edu>
Date: Wed, 26 Feb 1997 20:31:11 -0500 (EST)
To: http-wg@cuckoo.hpl.hp.com
Message-Id: <01IFVV0A6EJI00F2A5@SCI.WFBR.EDU>
Yaron Goland <yarong@microsoft.com> wrote:
>PS Who is going around saying that Microsoft will be making changes to
>its cookie support? It certainly isn't anyone who works for Microsoft.

	That was indicated in the original report of this problem,
the relevant portion of which is appended.

				Fote

=========================================================================
 Foteos Macrides            Worcester Foundation for Biomedical Research
 MACRIDES@SCI.WFBR.EDU         222 Maple Avenue, Shrewsbury, MA 01545
=========================================================================

From:	IN%"koen@win.tue.nl" 31-DEC-1996 10:01:45.29
To:	IN%"http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com"
Subj:	Problems with ..-state-mgmt-05.txt

draft-ietf-http-state-mgmt-05.txt (HTTP State Management Mechanism)
has been a Proposed Standard for about a month now.  This message
discusses two problems with draft-ietf-http-state-mgmt-05.txt I have
seen so far.  I feel that these problems need to be resolved in some
way as soon as possible.

These problems may or may not have an impact on the standards track
progress of the draft.  I will not discuss that issue in this message,
as others know more about such procedural matters.

Problem 1. Advice about sending Cache-Control: must-revalidate
==========
[...]

Problem 2. Downwards compatibility with existing cookie implementations
==========

(problem first identified by Martijn Koster)

If the following header (without the line breaks) is sent to Microsoft
Internet Explorer V3:

Set-cookie: xx="1=2&3-4";
    Comment="blah";
    Version=1; Max-Age=15552000; Path=/;
    Expires=Sun, 27 Apr 1997 01:16:23 GMT

then MSIE v3 will return the cookie

Cookie: Max-Age=15552000

and not xx="1=2&3-4", which would be the most reasonable thing to do
according to Netscape's cookie specification.  (By the way, Microsoft
will probably fix this problem in MSIE v4.)

The downwards compatibility scheme in the state management draft,
however, _relies_ on all existing browsers sending back xx="1=2&3-4"
when getting the Set-Cookie header above.  It therefore seems that
downwards compatibility, and smooth deployment, is impossible for the
current specification.

The state management draft assumes that existing clients are tolerant
when parsing Set-Cookie headers.  As is shown by MSIE v3, this
assumption is wrong.  A downwards compatibility scheme, which in my
opinion is crucially important if this specification is to be deployed
at all, will therefore have to rely on some other assumption.  

I propose using the assumption that unknown response headers are
ignored by all clients.  This leads to the following fix: the state
management specification defines a _new_ header for setting cookies,
for example "Cookie-Control", together with a rule that if a
Cookie-Control header is present in the response message, a compliant
client must ignore all Set-Cookie headers.  This would allow downwards
compatibility by sending two headers:

Cookie-Control: xx="1=2&3-4";
    Comment="blah";
    Version=1; Max-Age=15552000; Path=/;
Set-Cookie: xx="1=2&3-4"; Path=/; Expires=Sun, 27 Apr 1997 01:16:23 GMT

The "Version=1" directive in the Cookie-Control header above could
possibly also be removed.


Koen.
Received on Wednesday, 26 February 1997 17:33:48 EST

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