[lkml]   [1999]   [Mar]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    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,

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:50    [W:0.021 / U:1.648 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site