a question about forbid file copied?

NTFSD
1

hello, everyone.
I want to forbid the specified files to be copied. if someone use the
copy/paste to copy the specified file, we can compare the last modified
time to forbid the file copied. but if he open the file and copy the file
content to another file, also achieve his purpose of copy file, how can i
forbid this condition occurs?

think you advanced!

2

Forbid the open. There’s NO way to tell why the user opened the file. He
might even read the data do WM_COPYDATA into another process and write from
that process, which would make “forbid creation/writing to files by process
that opened protected file” approach futile.

Regards, Dejan.

deltali wrote:

hello, everyone.
I want to forbid the specified files to be copied. if someone use the
copy/paste to copy the specified file, we can compare the last modified
time to forbid the file copied. but if he open the file and copy the file
content to another file, also achieve his purpose of copy file, how can i
forbid this condition occurs?

think you advanced!

You are currently subscribed to ntfsd as: xxxxx@alfasp.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

–
Kind regards, Dejan M. MVP for DDK
http://www.alfasp.com E-mail: xxxxx@alfasp.com
Alfa Transparent File Encryptor - Transparent file encryption services.
Alfa File Protector - File protection and hiding library for Win32
developers.
Alfa File Monitor - File monitoring library for Win32 developers.

3

thanks Dejan.
what i want is user can read and write the protected file.but he can not
copy the file.
the best way is forbid the file open. thsi can forbid the file copied. but
the user can not use this file also.
if i can find from where the data read when i handle the IRP_MJ_WRITE.i
think this problem may be solved.

4

If I told you you’re asking for the impossible, I’d be underestimating the
problem:-) There is no way to do what you’re asking - if it’s to be 100%
secure.

Regards, Dejan.

deltali wrote:

thanks Dejan.
what i want is user can read and write the protected file.but he can not
copy the file.
the best way is forbid the file open. thsi can forbid the file copied. but
the user can not use this file also.
if i can find from where the data read when i handle the IRP_MJ_WRITE.i
think this problem may be solved.

You are currently subscribed to ntfsd as: xxxxx@alfasp.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

–
Kind regards, Dejan M. MVP for DDK
http://www.alfasp.com E-mail: xxxxx@alfasp.com
Alfa Transparent File Encryptor - Transparent file encryption services.
Alfa File Protector - File protection and hiding library for Win32 developers.

Alfa File Monitor - File monitoring library for Win32 developers.

5

— deltali wrote:
> thanks Dejan.
> what i want is user can read and write the protected
> file.but he can not
> copy the file.
IMHO, if the user is allowed to read the file, the
user can copy it, as long as the user can write
somewhere else…

Regards,
Manoj

________________________________________________________________________
Yahoo! India Matrimony: Find your partner online.
Go to http://yahoo.shaadi.com

6

Not even that much is required - sockets:-) Smart Cards, internal USB
tokens etc.

IMHO, if the user is allowed to read the file, the
user can copy it, as long as the user can write
somewhere else…

–
Kind regards, Dejan M. MVP for DDK
http://www.alfasp.com E-mail: xxxxx@alfasp.com
Alfa Transparent File Encryptor - Transparent file encryption services.
Alfa File Protector - File protection and hiding library for Win32
developers.
Alfa File Monitor - File monitoring library for Win32 developers.

7

> I want to forbid the specified files to be copied. if someone use the

copy/paste to copy the specified file, we can compare the last modified
time to forbid the file copied. but if he open the file and copy the file
content to another file, also achieve his purpose of copy file, how can i
forbid this condition occurs?

You cannot. Just plain and simple.

You can block the user from reading the data from the file, but, if the user
have the right to read, then this is no more your business to block the user
from doing anything with this data - like creating a copy of the file.

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

8

Try to hook Explorer’s Copy function, this is possible by COM object
wrapping.
Nevertheless, the command-line COPY or any other tools like GNU “cp” will
be able to copy.

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

----- Original Message -----
From: “deltali”
To: “Windows File Systems Devs Interest List”
Sent: Sunday, October 19, 2003 9:02 PM
Subject: [ntfsd] Re: a question about forbid file copied?

> thanks Dejan.
> what i want is user can read and write the protected file.but he can not
> copy the file.
> the best way is forbid the file open. thsi can forbid the file copied. but
> the user can not use this file also.
> if i can find from where the data read when i handle the IRP_MJ_WRITE.i
> think this problem may be solved.
>
> —
> You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com

9

Impossible. There is no distinction, at user level, between reading a
file, and copying a file. Reading is copying into memory. Copying is
reading, then writing.

– arlie

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of deltali
Sent: Sunday, October 19, 2003 1:02 PM
To: Windows File Systems Devs Interest List
Subject: [ntfsd] Re: a question about forbid file copied?

thanks Dejan.
what i want is user can read and write the protected file.but he can not
copy the file. the best way is forbid the file open. thsi can forbid the
file copied. but the user can not use this file also. if i can find from
where the data read when i handle the IRP_MJ_WRITE.i think this problem
may be solved.

You are currently subscribed to ntfsd as: xxxxx@sublinear.org To
unsubscribe send a blank email to xxxxx@lists.osr.com