Re: Encryption/Decryption

Tech-Archive recommends: Repair Windows Errors & Optimize Windows Performance

From: Arvind (arvinds_at_erivasystems.com)
Date: 08/31/04 

Date: Tue, 31 Aug 2004 11:09:19 +0530

My design goal is simple..

i want to change the file extension and encode the content..

in encrpting

Windows/arvind/toencode/

1.wmv
2.wmv
test.wmv

Thse are the 3 files in side "toencode" folder

i want to pass the parameters such as

\Windows\arvind\toencode\

i want application to encode all the 3 files to same password and change its
extension

to

1.enc
2.enc
test.enc

The same i want to do the same in reverse process for the decryption at
pocket pc level

1.enc
2.enc
test.enc

TO

1.wmv
2.wmv
test.wmv

and sore it in a same directory

is there any way for this?

i couldnt find any guide in this regard 

--
Thanks
Arvind
--
"eRiva Systems" - Where Technology Meets Life, Every Minute.
arvindr@erivasystems.com
www.erivasystems.com
"Don Dumitru [MSFT]" <dondu@online.microsoft.com> wrote in message
news:#xo6tStjEHA.3664@TK2MSFTNGP11.phx.gbl...
> For encrypting / decrypting multiple files at once, I assume that you
would
> need to change the programs.  If your design goal really is to process
*all*
> of the files in the folder, then you would use FindFirstFile /
FindNextFile
> to iterate through the files.  On the other hand, your design goal might
be
> to process the list of files which are named on the command line of the
> program, in which case the program would examine its command line
arguments,
> and apply the encrption / decryption to each of the filenames passed on
the
> command line.
>
> --Don
>
>
> --
> This posting is provided "AS IS" with no warranties, and confers no
rights.
>
> "Arvind" <arvinds@erivasystems.com> wrote in message
> news:%23F1Vw5ljEHA.1048@tk2msftngp13.phx.gbl...
> > your right!
> >
> > Now the problem is fixed and its working fine..
> >
> > now i have 2 applications (desktop/pda)
> >
> > and one more thing..can i do the encryption of list of files present in
> > the
> > folder
> >
> > like
> >
> > test.abc
> > test1.abc
> > etc
> >
> > to
> >
> > encrypt serially one by one?
> >
> > and same for decrypting one by one automatically
> >
> > how can we do that?
> >
> > --
> >
> > Thanks,
> >
> > Arvind
> >
> > --
> > "eRiva Systems" - Where Technology Meets Life, Every Minute.
> >
> > arvindr@erivasystems.com
> >
> > www.erivasystems.com
> >
> > "Don Dumitru [MSFT]" <dondu@online.microsoft.com> wrote in message
> > news:OaZxk9LhEHA.596@TK2MSFTNGP11.phx.gbl...
> >> From the thread going on in the microsoft.public.windowsce.embedded.vc
> >> newsgroup, I am going to assume that this is getting resolved as an
issue
> > of
> >> using an ANSI pass-phrase on the desktop, and a Unicode pass-phrase on
> >> the
> >> device.
> >>
> >> --Don
> >>
> >> --
> >> This posting is provided "AS IS" with no warranties, and confers no
> > rights.
> >>
> >>
> >> "Don Dumitru [MSFT]" <dondu@online.microsoft.com> wrote in message
> >> news:OPB1KmLhEHA.904@TK2MSFTNGP09.phx.gbl...
> >> > Can you provide the full URL for the sample, so I can be sure that we
> > are
> >> > looking at exactly the same thing?  Without it, I don't know which
> > actual
> >> > sample you might be looking at, and I can only guess at what problems
> > you
> >> > are having, and I won'd be able to reliably reproduce the behavior
> > myself.
> >> >
> >> > From your description, it sounds like the sample works by generating
an
> >> > RC4 key into a key container for the user, and then encrypting /
> >> > decrypting the file using that key.  I am guessing here, but...  You
> >> > run
> >> > an "init user" app on both the sender and the receiver, and give it
the
> >> > same pass-phrase?  And it generates an RC4 key and places it in the
> > user's
> >> > key container?  You then run an encryption program, which uses the
> > stored
> >> > key to encrypt a file.  You move the file to the other machine, and
run
> >> > the decryption program, which accesses the stored key and decrypts
the
> >> > file.
> >> >
> >> > That's what it sounded like it was doing.
> >> >
> >> > The first thing to verify would be that you can decrypt the file
> >> > successfully, on the desktop, without Windows CE involved.  The next
> > thing
> >> > to do is to build the "init user" app for Windows CE, and run it, and
> > see
> >> > if it succeeds.  Ideally, you would single-step through with a
> >> > debugger,
> >> > and examine each error return, in case the application itself does
not
> >> > adequately report some error that it receives.  Finally, you need to
> > build
> >> > the decryption program for Windows CE, run it, and again hopefully
> >> > single-step through it to examine error codes which might be getting
> >> > returned from various API's.
> >> >
> >> > From your description of how the app's are supposed to work, I would
> > look
> >> > closely at how the "init user" and decryption programs access the RC4
> > key
> >> > stored in the key container.  Since Windows CE has a different user
> > model
> >> > than the desktop, and since key containers are associated with users,
> > this
> >> > is an area where the app could be getting different behavior than it
> >> > was
> >> > expecting.  The most likely case is that some error is being
returned,
> > and
> >> > the app simply isn't checking the error code, and blindly cruising
> >> > along
> >> > as if the API had succeeded.
> >> >
> >> > --Don
> >> >
> >> >
> >> > "Arvind" <arvinds@erivasystems.com> wrote in message
> >> > news:%23yBu2MBhEHA.3964@TK2MSFTNGP12.phx.gbl...
> >> >>i got it from www.msdn.com
> >> >>
> >> >> basically theres 2 applications..
> >> >>
> >> >> desktop for encrypting
> >> >>
> >> >> pocket pc for decrypting..
> >> >>
> >> >> ive used RC4 to encrypt and using the same to decrypt..
> >> >> but im getting the wrong output file.
> >> >>
> >> >> i have used the inituser for client for storing and generating
> >> >> keys(Container)
> >> >>
> >> >> but i couldnt find the same init user application for pocket pc
> >> >>
> >> >> can i get one?
> >> >>
> >> >> --
> >> >> Thanks,
> >> >>
> >> >> Arvind
> >> >>
> >> >>
> >> >> --
> >> >> "eRiva Systems" - Where Technology Meets Life, Every Minute.
> >> >>
> >> >> arvindr@erivasystems.com
> >> >>
> >> >> www.erivasystems.com
> >> >>
> >> >> "Don Dumitru [MSFT]" <dondu@online.microsoft.com> wrote in message
> >> >> news:#5ujxoYgEHA.1356@TK2MSFTNGP09.phx.gbl...
> >> >>> Can you provide a URL for the sample which you used?  Was it a
> > specific
> >> >>> Windows CE sample, or a more general Win32 sample?  Presumably,
some
> >> >>> function call is failing, and the sample isn't reporting the
failure.
> >> >>>
> >> >>> --Don
> >> >>>
> >> >>> --
> >> >>> This posting is provided "AS IS" with no warranties, and confers no
> >> >> rights.
> >> >>>
> >> >>>
> >> >>> "Arvind" <arvinds@erivasystems.com> wrote in message
> >> >>> news:u1BRZURgEHA.2764@TK2MSFTNGP11.phx.gbl...
> >> >>> > Hello,
> >> >>> >
> >> >>> > im trying to use crypto API's in pocket pc (EVC++)
> >> >>> >
> >> >>> > to encrypt the WMV Files and decrypt the same.
> >> >>> >
> >> >>> > what i did is just copied the sample application which is
provided
> > in
> >> >> the
> >> >>> > help and tried to run in the pocket pc
> >> >>> >
> >> >>> > the application for encryption creates the destination file but
the
> >> >>> > content
> >> >>> > are not added in that..
> >> >>> > (File shows 0 BYTES)
> >> >>> >
> >> >>> > is there any other way around i have to try?
> >> >>> >
> >> >>> > plese let me know ur ideas..
> >> >>> >
> >> >>> > --
> >> >>> > "eRiva Systems" - Where Technology Meets Life, Every Minute.
> >> >>> >
> >> >>> > arvindr@erivasystems.com
> >> >>> >
> >> >>> > www.erivasystems.com
> >> >>> >
> >> >>> >
> >> >>>
> >> >>>
> >> >>
> >> >>
> >> >
> >> >
> >>
> >>
> >
> >
>
>

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