mirror of https://github.com/acidanthera/audk.git
8d65d3b25e
Call Tcg2PhysicalPresenceLibProcessRequest() to process pending PPI requests from PlatformBootManagerAfterConsole(). Laszlo understanding of edk2 is that the PPI operation processing was meant to occur *entirely* before End-Of-Dxe, so that 3rd party UEFI drivers couldn't interfere with PPI opcode processing *at all*. He suggested that we should *not* call Tcg2PhysicalPresenceLibProcessRequest() from BeforeConsole(). Because, an "auth" console, i.e. one that does not depend on a 3rd party driver, is *in general* impossible to guarantee. Instead we could opt to trust 3rd party drivers, and use the "normal" console(s) in AfterConsole(), in order to let the user confirm the PPI requests. It will depend on the user to enable Secure Boot, so that the trustworthiness of those 3rd party drivers is ensured. If an attacker roots the guest OS from within, queues some TPM2 PPI requests, and also modifies drivers on the EFI system partition and/or in GPU option ROMs (?), then those drivers will not load after guest reboot, and thus the dependent console(s) won't be used for confirming the PPI requests. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> |
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| .. | ||
| BdsPlatform.c | ||
| BdsPlatform.h | ||
| PlatformBootManagerLib.inf | ||
| PlatformData.c | ||
| QemuKernel.c | ||