Re: [GIT PULL] Load keys from signed PE binaries

Florian Weimer
2013-02-28T19:41:25Z

* Matthew Garrett:

>> Would it be possible to have a signed bootloader that allows booting
>> Win8 from within the secure environment, or it could exit the secure
>> environment and run unsigned grub?
>
> What would stop the unsigned grub from installing a firmware hook that
> lies about whether or not Secure Boot is enabled, and then booting
> Windows?

Windows would not have access to the product key because it is stored
in a variable without EFI_VARIABLE_RUNTIME_ACCESS, so WGA and other
checks will fail, and the user will notice.

(Not sure if it is implemented this way, my test machine lost the
firmware-embedded product key after the mainboard was replaced.)