8 replies to this topic

[forsajt]

Hi guys. I'm having hard time trying to understand the twisted semantics of grub4dos' menu.lst. Could you please help me a bit?

I have 3 partitions on my HD (I have installed grub4dos as default bootmgr entry on active partition (hd0,0)):

hd0,0 - system reserved, active
hd0,1 - windows
hd0,2 - windows

Now what I'm trying to achieve is:

1. Do not display any menus, instead display blank screen with text "Please enter password: ".

2. Take action as described by following pseudocode:

if(password==123456)
{
    if(not hidden(partition 2)) hide partition 2
    if(hidden(partition 1)) unhide partition 1
    boot partition 1
}
else
{
    if(not hidden(partition 1)) hide partition 1
    if(hidden(partition 2)) unhide partition 2
    boot partition 2
}

3. Optionally:
-Set 10 sec timeout (i.e if no key is pressed, then do the second part).
-If ESC key is pressed, then do the second part.

Is it even possible to configure grub4dos this way? Thanks for your time.

Edited by forsajt, 12 March 2015 - 02:32 PM.

[Wonko the Sane]

Maybe you want to look at grub4dos batch language?

Essentially it is very similar to "common" NT/2K/XP/Later CMD.EXE batch, you could get (or congfigure) one of the grub4dos "silent" mods and have it run the batch.

 

Wonko

[steve6375]

http://www.rmprepusb...c-grub4dos-menu

http://www.rmprepusb...orials/grub4dos

 

 

This may go some way - note that it assumes that the two Windows installs are separate and do not use the same BCD.

i.e. each Windows partition has \bootmgr and \boot\BCD

 

menu.lst

=======

clear
# set wanted password
set mypwd=123456
set ask=
# ask a question and get an answer into ask variable
set /p:10 ask=Please enter password:
if "%ask%"=="%mypwd%" hide (hd0,1) && unhide (hd0,2) && root (hd0,2) && chainloader (hd0,2) && boot
hide (hd0,2) && unhide (hd0,1) && root (hd0,1) && chainloader (hd0,1) && boot

[Wonko the Sane]

8 bytes saved :

 

if "%ask%"=="%mypwd%" hide (hd0,1) && unhide (hd0,2) && root (hd0,2) && chainloader +1 && boot
hide (hd0,2) && unhide (hd0,1) && root (hd0,1) && chainloader +1 && boot

 

 

Now, more seriously, isn't there a way through one of the "silent" builds and with some of the usual trickery to make use of the password feature of grub4dos? 

 (not that it is actually "secure", but at least it is not "plain text")

 

 

Wonko

[steve6375]

There is no timeout on the grub4dos password.

Things can be done with the code sample to improve it - e.g. use a black text on black background, redirect to nul, encrypt the whole menu.lst file, etc. But first lets see if the sample works and works the way the 'customer' wants...

[forsajt]

Thanks guys, it seems this is just what I wanted. I have a couple of questions though.
 
What is root command? Do I have to use it? Can't I just issue chainloader (hd0,1)/bootmgr instead?

How about muting the debug messages? 

Edited by forsajt, 13 March 2015 - 12:11 AM.

[steve6375]

root command sets the root partition. It may not be needed but it should not hurt to use it.

If you mean muting the grub4dos startup messages, see the link I gave previously

http://www.rmprepusb...essages-silent-

[steve6375]

If you don't want anyone to see what you have typed for the password, use

set mypwd=123456
set ask=
color standard 11
# ask a question and get an answer into ask variable
echo Please enter password :
# set text color to black (same as background colour)
color standard 0
set /p:10 ask=xx > nul
# set text colour to bright cyan = 8 + 3
color standard 11

[Wonko the Sane]

I was thinking more *along the lines of* (set aside temporarily the "silent" version of grub4dos that will be used in the final form) of:
menu.lst:
 
 

timeout 0
default 0

title
echo Imagine this to be just "Enter password:" centered
serial --unit=0 --speed=115200
terminal --silent serial console
password goofy || clear && configfile /normal.lst
echo This is protected
pause

normal.lst:
 

timeout 5
default 0
title Normal
echo This is normal
pause

Wonko