Inline:
On 9/20/06 1:23 PM, "James D. Stallard" <james@leafgrove.com> spoketh to
all:
Thor
I have to ask the obvious question:
. Why are you re-inventing the (perfectly god) wheel?
The filesystem is easy to manipulate from within SQL Stored Procedures, or
directly from the app, with VB or WSH - or you're preferred development
environment. We already know how to secure a filesystem and it's credentials
database is already available to you as part of the OS. Lastly, the
filesystem is much faster than SQL at returning file objects, due to the way
in which they are stored.
Well, a couple of reasons. Like I said in my post to Matthew,
replication/portability to secure destinations is the most pressing reason.
If this were a static app that only lived in the DMZ, it would be a no
brainer-I'd leave things as they are now. But it's not-- I need to securely
move files around to various locations from the internal to the DMZ and to
my off-site location. Doing this from a file-system standpoint brings in
issues of transport (CIFS,FTP, HTTP, etc), authorization infrastructures,
trusts, and also file replication integrity. To do it securely is tricky...
I'm doing it now at the file-system level, but it just seems like there is a
better way to do it.
It's quite likely that the only thing SQL can do faster/better in your
scenario is return the "Select *" query faster than the filesystem could
return a "DIR" command. Everything else will be ponderous by comparison.
It strikes me that this may have something to do with why WinFS hasn't made
it into Longhorn as databases simply aren't designed for this type of data.>
Valid points all... But to me, binary data is binary data - I don't know
that I would say "dbs are not designed for this type of data," particularly
in the case of SQL 2005 - what's the real difference between a web server
delivering binary data to a browser from a file or a stream object? I've
done a good bit of research into various developer newsgroups about this,
and many people share your feelings of "why re-invent the wheel." But I
have to say, in most of the cases where people say "I want to do this- how
do I?" no one really answers the question- rather, they say "don't do it
like that."
I can totally see how performance could be an issue, but when my clients log
on to my secure site to view project status, they'll only be looking at a
few documents per project site. But I'm still not totally convinced that
performance issues will be evident to the user at all. There is something
to be said for dynamically creating needed content streamed directly to the
user's browser in these cases.
Re-inventing the wheel here I think really gives us the opportunity to take
advantage of some interesting security mechanisms, both in the areas of
replication/portability and access controls (think views).
Thanks for the thoughts... Still chewing on it all ;)
t
Hope this helps crystallise your thoughts.
Cheers
James
James D. Stallard, MIoD
Microsoft and Networks Infrastructure Technical Architect
Leafgrove Limited
Web: www.leafgrove.com
Email: j a m e s @ l e a f g r o v e . c o m (remove the spaces)
Mobile: +44 (0) 7979 49 8880
Skype: JamesDStallard
-----Original Message-----
From: listbounce@securityfocus.com [mailto:listbounce@securityfocus.com] On
Behalf Of Thor (Hammer of God)
Sent: 19 September 2006 19:35
To: Focus-MS
Subject: Storing Images in SQL Server (2005)
Greetings security professionals:
I'm starting a new development project where I'm considering moving image
and document data into my database rather than storing the files in the
server filesystem.
I've been mulling over the security implications of this, and want to see
what others are doing in this area. The first thing that comes to mind is
row-level security, and how others are handling the "flow-through" from
table permissions to file system permissions where you're creating the
resultant files. In my environment, I have directory structures for
individual clients, with NTFS permissions applied to the different client
directories so Client A can only see their own data, and not Client B's.
I'm concerned that a possible breach could allow Client A to see Client B's
data unless I impose row-level security on the DB or create multiple views
for each client. I'm open to thoughts on how to best manage that. Also,
are you guys "streaming" the content from DB directly into the browser, or
are you creating a temporary file first, storing that in the file system,
and then referencing that temp file? If so, how are you handling
permissions on that? Via inherited directory permissions? And what about
the context of the web user? You give them delete permissions to "clean up"
the temporary files? The "steaming" context seems a better way to do it...
Just seeing what issues those who have gone through the deployment process
have run into.
Thx
T
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