lkml.org 
[lkml]   [1999]   [Mar]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: P-III serial number security in Linux
    On Wed, Mar 03, 1999 at 11:49:07PM +0000, Philipp Rumpf wrote:

    > > The serial number, although proven by c't to be possible to switch on
    > > without rebooting the machine (using a powermanagement trick), is not
    >
    > Processor reset, AFAIK. Not Power Management. You set the CMOS shutdown state
    > byte, ask the keyboard controller to reset (or have a triple-fault) and come
    > back to life. As Intel's proposal at that time was to switch off the PSN after
    > the system booted, it would not have been disabled. The current way is to dis-
    > able it in the BIOS, which will work.

    Well, I can only base on what I've heard. The approach you describe above
    will certainly work, but I have read somewhere that putting the CPU into off
    mode for a short moment through power management worked too, somehow.

    > > Intel's serial number disabling utility 'fixes' this security hole (or
    > > backdoor?) by disabling the serial number feature repeatedly every 15
    > > seconds.
    >
    > Oh. New to me. AFAIK, they only said it to be disabled by the BIOS.

    Hmm, I think I'll have to dig the article out somewhere. I think the
    BIOS way is 'fix #2' when they realized the first won't work.

    > Nope, you have to change the bit in the NVRAM that says the PSN is to be
    > disabled. No problem though if you know what mobo you're running on.

    Yeah, both the Awards and AMIs (which are the most common) have a
    NVRAM layout description in the FlashROMs, all with bit fields and menu
    item texts. Piece of cake to find the right bit in this case.

    Have fun,
    Vojtech

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.rutgers.edu
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:50    [W:0.021 / U:121.736 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site