Board index » delphi » Password program...Encrypting .pwd files

Andrey

Delphi Developer
Wed, 18 Jun 1902 08:00:00 GMT

Password program...Encrypting .pwd files

Hi!
I'm writing a password program that will start when the pc starts. There
is just on problem, when a pc starts I can easily disable autoexec.bat
from running, is there any way to prevent the user from disabling
autoexet.bat? Also how can I encrypt files?
                                        Andrey

 
Paul Holde

Delphi Developer
Wed, 18 Jun 1902 08:00:00 GMT

Re:Password program...Encrypting .pwd files


Quote
Andrey wrote:
> Hi!
> I'm writing a password program that will start when the pc starts.
> There
> is just on problem, when a pc starts I can easily disable autoexec.bat

> from running, is there any way to prevent the user from disabling
> autoexet.bat? Also how can I encrypt files?
>                                         Andrey

well, encryption is easy and for anyone who isnt a serious hacker
unbreakable.  Read in the passwords as a series of char, for
each char get the ordinate value (ord(char)) and do some calculation
on it, eg (ord(somechar) XOR 4) * 7) XOR 6.

i dont know but something like that!  the next thing is to write it to
a file!

now when the person enters the password in my opinion you should
ONLY HAVE A one way encryption, eg, you encrypt what he has
just entered and compare the number values of what the original
was.

for your other question, i was at this college once and they had
dos and nothing else.  they didnt want access to be given
to everyone so they introduced a password/menu program.  It
wasnt particulary impressive BUT it did have a neat bit of
code which did something to the harddrive which made it
impossible to get out of any of the loadup, never found out
what it was though.... :-(  Might be worht looking through
a list of interupts for the appropriate call, try rbrowns
page..

jim

Eric Lawrenc

Delphi Developer
Wed, 18 Jun 1902 08:00:00 GMT

Re:Password program...Encrypting .pwd files


Quote
>I'm writing a password program that will start when the pc starts. There
>is just on problem, when a pc starts I can easily disable autoexec.bat
>from running, is there any way to prevent the user from disabling
>autoexet.bat? Also how can I encrypt files?

First add the line
SWITCHES= /N
to the first line of the config.sys.  This prevents the f5/f8 bypass of the
startup
processing.  The next line should call a CTRL-Break inhibiter.  This "eats"
the control-break sequence which allows a user to stop the autoexec.bat in
mid run. You can find free inhibitors on the 'net.

Make the password program the first line of the autoexec.bat.

Any particular reason you're not just using the CMOS password?

Eric Lawrence
Lead Programmer
Delta Programming Group
delta...@wam.umd.edu

Kim Robert Bl

Delphi Developer
Wed, 18 Jun 1902 08:00:00 GMT

Re:Password program...Encrypting .pwd files


"Eric Lawrence" <delta...@wam.umd.edu> said:

Quote
>Any particular reason you're not just using the CMOS password?

I just thought I'd mention that on my good old 486 with an
AWARD 4.50G bios, you can bypass the CMOS password by entering
(..drumfill..) "award" as the password :) .. hehe. nice huh?
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 Kim Robert Blix  ( kb...@c2i.net )

 "How do you shoot the devil in the back?"
 "What if you miss?" -Verbal Kint
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

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