Encryption filter above a redirector.

NTFSD
2

I would say the encryption filter must always be below redirector,

but it depends on the logic of the encryption filter.

No, you can’t know, and you should not know what a filter below you

will do with the file. That’s principle of the layered filter stack.

L.

3

Hi,

Encryption and Decryption on Networks is not that easy as in the case of Local files. Please check the article to understand this
http://www.osronline.com/article.cfm?article=226

Thanks & Regards
Aishwary Bhashkar
Sr. Software Engineer
R Systems International Ltd.

4

Hi Ladislav Zezula,

Just one question how asure that you put your filter or minifilter below redirector.

Thanks & Regards

Aishwary Bhashkar
Sr. Software Engineer
R Systems International Ltd.

5

Hi Ladislav Zezula,

Just one question how to asure that you put your filter or minifilter below
redirector.

Thanks & Regards

Aishwary Bhashkar
Sr. Software Engineer
R Systems International Ltd.

6

First, you are using the term redirector which has a specific meaning of a
network file system such as LANMAN, but from your description you are
talking about a driver that places the file in another location on the same
system.

As far as your question, your encryption driver should not care or need to
do anything special. You see file D:\folder\A.txt you encrypt and decrypt
it as needed. Just because a driver below you changes the path to
D:\RedirectFolder\B.rcc should not matter. Now, it is true if your driver
only encrypts D:\folder and the lower driver is removed or disabled in some
manner the file B.rcc is going to be encrypted, but there are always things
like this in such a model. You will never be able to cover them all, so
trying is foolish.

Bottom line, your filter decrypts/encrypts files (perhaps for a limited set
of folders, names, etc). If someone outside of your scope, be it a lower
filter, a user who mounts the disk on another machine, or some other
mechanism changes the environment you cannot stop it. The best you can do
is warn people of potential problems, trying to handle this in your code is
a fools game.

–
Don Burn (MVP, Windows DDK)
Windows 2k/XP/2k3 Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr
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“ganesh pashupathi” wrote in message
news:xxxxx@ntfsd…
Hi,

Assume that below my encryption filter driver there is a redirector driver.

For example if I save a file to the folder D:\Folder\A.txt (A.txt should be
encrypted) this redirecting driver writes the file to
D:\RedirectFolder\B.rcc. “D:” is the drive that the redirecting driver is
monitoring.

Is there a way for me to know that the file B.rcc should be encrypted?

Thanks in advance,
~ganesh