FreeBSD and User Security

[perryh at pluto.rain.com]

> > It is my understanding that since 1995 all computers must have  
> > a hardware back door that permits undetectable access by the 
> > government to the computer. This capability can be implemented 
> > using System Monitor(Maintenance) Mode which is built into all 
> > x86 computers now. It would appear that, if you are connected 
> > to the internet, the government has access to your computer.
>
> if it were true, this "system maintenance mode" would have to 
> access your network card in parallel with main OS without making 
> conflicts
 
A near-trivial exercise in virtualization, provided it knows what 
kind of card is in use and what addresses it occupies, which is
rather easy if the "card" is in fact built onto the mainboard.  Of
course, it is also trivial to defeat it by using an add-in card
instead of the one on the mainboard, esp. a card whose design did
not exist when the bios was written.

Cycles consumed by SMM might also explain why some PCs' clocks seem
to run slower than real time ...