2007, HTTP and session based authentication.

[Anthony Jones]

I've been searching the web and have found very little info about the
following problem. This surprises me because I would have thought it to
affect a lot of sites. Therefore I'm wondering if I missing something
obvious that everyone else knows.

I have a site which in part contains a Document management system, many
documents are office documents of which some are powerpoint presentations.

The site requires the user to login and tracks the login status via the
session. (An ASP session is tracked by an 'in-memory' cookie, such a cookie
is held only in process memory and is not persisted to disk).

When a user requests a document such as a powerpoint presentation the server
checks that the authenticated user is authorized to view the document and if
so allows the user view it.

Up until Powerpoint 2007 this approach worked fine.

Now with 2007 powerpoint hijacks the download of the document. It spins up a
separate powerpoint process (rather than using components integrated into
the IE process). It aborts the current download initiated IE and sends its
own request for the URL of the document(it uses range headers so that it can
utalise whats been downloaded so far).

The problem is that the request generated by the powerpoint process will not
include the session cookie which is held only in-memory in the IE process.
Therefore the server sees an unauthenticated session and rejects the
download.

I'm finding it difficult to believe the I'm in the minority for having sites
require authentication before allow access to powerpoint slides. Therefore
my current thinking is I'm being dense and missing something obvious.

 

[Steve Rindsberg]

I'm finding it difficult to believe the I'm in the minority for having sites

require authentication before allow access to powerpoint slides. Therefore
my current thinking is I'm being dense and missing something obvious.

I rather suspect that you are indeed in the minority, both for requiring
authentication before access and again because of the method. That's not to
suggest that there's anything wrong with what you're doing, just that I doubt
that many people are doing it, else we'd hear about this sort of thing far more
often here over time.

PPT 2007 breaks existing code in quite a few different ways. It wouldn't
surprise me that it breaks something in your process. It sounds as though you
have the tools you need to present a very thorough and convincing case to MS
support, and I suspect that's where you'll need to turn for help with this.

Not much of an answer, I know ...

[OK folks. Prove me wrong.]

 

[Austin Myers]

Anthony,

Drop me an email, I would like to kick this around with you.

Austin


(e-mail address removed)

 

[John Langhans [MSFT]]

Hello Anthony,

It's possible that your problem is addressed by the hotfix for the issue
described in the following KB article:

http://support.microsoft.com/kb/935869

Hope this helps,

John Langhans [MSFT]
Supportability Program Manager | Product Quality and Online