W3C home > Mailing lists > Public > ietf-http-wg@w3.org > October to December 2010

Re: Does no-store in request imply no-cache?

From: David Morris <dwm@xpasc.com>
Date: Sun, 17 Oct 2010 17:05:53 -0700 (PDT)
cc: HTTP Working Group <ietf-http-wg@w3.org>
Message-ID: <Pine.LNX.4.64.1010171702570.15971@egate.xpasc.com>

I interpret NOSTORE as a stricter restriction than NOCACHE.
If it can't be stored, it can't be used in a subsequent
response.

If I recall the discussion from 10 years ago correctly, the
intent was to reduce the posibility that private information
could leak via even temporary storage.

Dave Morris

On Mon, 18 Oct 2010, Mark Nottingham wrote:

> Thoughts re: the below?
> 
> My inclination is to clarify "any response to it" so that a cache can
> use the same cached response to serve multiple requests with no-store in
> them (or not).
> 
> Cheers,
> 
> 
> Begin forwarded message:
> 
> > From: Alex Rousskov <rousskov@measurement-factory.com>
> > Date: 23 September 2010 9:47:57 AM AEST
> > To: Mark Nottingham <mnot@yahoo-inc.com>
> > Cc: Squid Developers <squid-dev@squid-cache.org>
> > Subject: Re: Does no-store in request imply no-cache?
> > 
> > On 09/22/2010 05:05 PM, Mark Nottingham wrote:
> > 
> >> Strictly, as a request directive it means "you can't store the
> >> response to this request" -- it says nothing about whether or not you
> >> can satisfy the request from a cache.
> > 
> > Hi Mark,
> > 
> >    Let's assume the above is correct and Squid satisfied the no-store 
> > request from the cache. Should Squid purge the cached response afterwards?
> > 
> > If Squid does not purge, the next regular request will get the same 
> > cached response as the no-store request got, kind of violating the "MUST 
> > NOT store any response to it" no-store requirement.
> > 
> > If Squid purges, it is kind of silly because earlier requests could have 
> > gotten the same "sensitive" information before the no-store request came 
> > and declared the already cached information "sensitive".
> > 
> > Thank you,
> > 
> > Alex.
> > 
> > 
> >> See also:
> >>  http://tools.ietf.org/html/draft-ietf-httpbis-p6-cache-11#section-3.2.1
> >> 
> >> 
> >> On 23/09/2010, at 4:27 AM, Alex Rousskov wrote:
> >> 
> >>> Hello,
> >>> 
> >>>    One interpretation of RFC 2616 allows the proxy to serve hits when
> >>> the request contains "Cache-Control: no-store". Do you think such an
> >>> interpretation is valid?
> >>> 
> >>>  no-store
> >>>      The purpose of the no-store directive is to prevent the
> >>>      inadvertent release or retention of sensitive information (for
> >>>      example, on backup tapes). The no-store directive applies to the
> >>>      entire message, and MAY be sent either in a response or in a
> >>>      request. If sent in a request, a cache MUST NOT store any part of
> >>>      either this request or any response to it.
> >>> 
> >>> Thank you,
> >>> 
> >>> Alex.
> 
> --
> Mark Nottingham   http://www.mnot.net/
> 
> 
> 
> 
Received on Monday, 18 October 2010 00:06:27 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 27 April 2012 06:51:29 GMT