Hello
I have been assigned o build a simple full disk encryption system .
Here is what i think i have to do ( please correct me if im wrong ) .
Write an Extended MBR which hooks int 13 and then loads the encrypted
MBR then this MBR goes to load the kernel . Write a driver for
disk.sys to provide the OTF encryption and decryption facilities later
on .
I have done the Extended MBR but im having some problems handling
extended disk read and write ( Not woking properly once i put in AES
). Also i am not clear on what is the correct way after the system
loads the kernel ( which drivers have to be written ) . I would like
that if any of you have carried out a similar project before please
help me out . Im willing to pay for the support and concultancy
offered . Also if anyone can provide me with skeleton code for such a
system please let me know .
Thanking you in advance
Alex Dirk
Alex,
There’s a lot of discussions about this in the archives. Take a look.
Are you encrypting “in place” or to a separate buffer?
Chuck
----- Original Message -----
From: “Alex Dirk”
To: “Windows System Software Devs Interest List”
Sent: Monday, February 28, 2005 11:43 AM
Subject: [ntdev] Full Disk Encryption - Please help
> Hello
>
> I have been assigned o build a simple full disk encryption system .
> Here is what i think i have to do ( please correct me if im wrong ) .
> Write an Extended MBR which hooks int 13 and then loads the encrypted
> MBR then this MBR goes to load the kernel . Write a driver for
> disk.sys to provide the OTF encryption and decryption facilities later
> on .
>
> I have done the Extended MBR but im having some problems handling
> extended disk read and write ( Not woking properly once i put in AES
> ). Also i am not clear on what is the correct way after the system
> loads the kernel ( which drivers have to be written ) . I would like
> that if any of you have carried out a similar project before please
> help me out . Im willing to pay for the support and concultancy
> offered . Also if anyone can provide me with skeleton code for such a
> system please let me know .
>
> Thanking you in advance
>
> Alex Dirk
Alex,
You should first make sure that your AES encryption system works for
a non boot disk. For this you should develop a filter above disk.sys which
will offset all the requests by +1 sector to account for your encryption header
http://winfs.tripod.com
On Mon, 28 Feb 2005 16:18:43 +0700, Chuck Batson
wrote:
> Alex,
>
> There’s a lot of discussions about this in the archives. Take a look.
> Are you encrypting “in place” or to a separate buffer?
>
> Chuck
>
> ----- Original Message -----
> From: “Alex Dirk”
> To: “Windows System Software Devs Interest List”
> Sent: Monday, February 28, 2005 11:43 AM
> Subject: [ntdev] Full Disk Encryption - Please help
>
> > Hello
> >
> > I have been assigned o build a simple full disk encryption system .
> > Here is what i think i have to do ( please correct me if im wrong ) .
> > Write an Extended MBR which hooks int 13 and then loads the encrypted
> > MBR then this MBR goes to load the kernel . Write a driver for
> > disk.sys to provide the OTF encryption and decryption facilities later
> > on .
> >
> > I have done the Extended MBR but im having some problems handling
> > extended disk read and write ( Not woking properly once i put in AES
> > ). Also i am not clear on what is the correct way after the system
> > loads the kernel ( which drivers have to be written ) . I would like
> > that if any of you have carried out a similar project before please
> > help me out . Im willing to pay for the support and concultancy
> > offered . Also if anyone can provide me with skeleton code for such a
> > system please let me know .
> >
> > Thanking you in advance
> >
> > Alex Dirk
>
> —
> Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256
>
> You are currently subscribed to ntdev as: xxxxx@gmail.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com
>
–
Hello
As for a full disk encryption the sytem is divided into 2 parts the (
Real mode Preboot system , and the later drivers ) . Im right now
stuck with the real mode pre boot driver the problem is that to test
it im first checking it out on an AES ( 256 bit key and 128 bit block
) encrypted disk . But for some strage reason my code does not work
fully . On version < DOS 7 which do not use int 13 extensions it works
fine ( also when i implemented a XOR ( not AES ) based encryption it
worked just fine i even loaded win 98 though it ran in compatibility
mode ) , Also in a simple boot up mode ( after pressing F8 ) when safe
mode is selected in command prompt it works fine ( currently testing
E-MBR for dos only ) . I belive i have problem with how im using the
segments in real mode .
I have hooked int 13 extensions but they do not seem to work properly
when AES comes in. Im using the windows startup floppy to create the
test envoirnment ( so to get the preboot working first ) . If anyone
has any idea what could be wrong or any specific procedure which is to
be followed while loading this pre boot system ? .
Thanking you
Alex Dirk