PGP source code

[M Taylor]

On Tue, 4 Sep 2001, Richard Clayton wrote:

> In 1997 there was a great deal of interest in an announcement by Intel
> of "programmable microcode" such that 2K chunks of microcode could be
> replaced at POST time (when you first switch the machine on) so as to
> correct bugs (such as the "floating point problem" that caused them so
> much PR trouble).
>
> There's a little more in this October 2000 BYTE article:
>
>         http://www.byte.com/documents/s=479/BYT20001016S0006/
>
> Although BYTE talks about "checksums", the microcode is signed (I am
> told on excellent authority [though admittedly, my memory may not be as
> good as the authority!]) by a 2048 bit RSA key...
>
> There is indeed, as BYTE says, very little documented about this on
> Intel's site (and certainly no mention of RSA or of the way that the
> chip checks the signature), though there is occasional mention of
> microcode upgrades for chips such as the Xeon.

<http://developer.intel.com/design/pentium4/manuals/24547204.pdf>
Section 8.11.3 (pg 309)

Based on my reading of the details given, it is not talking about a RSA
style of signature. I might be wrong though, it is lower level then I am
use to dealing with.