[edk2-devel] TianoCore Community Design Meeting Minutes - Feb 21, 2020

[Ni, Ray]

Sunny,
Let's discuss in this week's meeting to see whether the below enhancement proposal can be aligned first.

Thanks,
Ray

> -----Original Message-----
> From: devel at edk2.groups.io <devel at edk2.groups.io> On Behalf Of Wang, Sunny (HPS SW)
> Sent: Wednesday, March 4, 2020 12:12 PM
> To: devel at edk2.groups.io; Ni, Ray <ray.ni at intel.com>; Sean Brogan <sean.brogan at microsoft.com>; Kinney, Michael D
> <michael.d.kinney at intel.com>
> Cc: Wang, Sunny (HPS SW) <sunnywang at hpe.com>; Wei, Kent (HPS SW) <kent.wei at hpe.com>; Spottswood, Jason
> <jason.spottswood at hpe.com>
> Subject: Re: [edk2-devel] TianoCore Community Design Meeting Minutes - Feb 21, 2020
> 
> Sorry for not making any progress since last meeting.
> Sure! I will work on enhancing the variable policy to support partial protection and recovery. However, the update will be
> late because I need to first deal with other urgent stuff.
> By the way, thanks for giving a lot of valuable comments at our offline discussion, Ray.  :)
> 
> Regards,
> Sunny Wang
> 
> -----Original Message-----
> From: devel at edk2.groups.io [mailto:devel at edk2.groups.io] On Behalf Of Ni, Ray
> Sent: Wednesday, March 4, 2020 11:46 AM
> To: Sean Brogan <sean.brogan at microsoft.com>; Kinney, Michael D <michael.d.kinney at intel.com>; Wang, Sunny (HPS SW)
> <sunnywang at hpe.com>
> Cc: Ni, Ray <ray.ni at intel.com>; devel at edk2.groups.io
> Subject: Re: [edk2-devel] TianoCore Community Design Meeting Minutes - Feb 21, 2020
> 
> Variable policy works well on protecting a whole variable.
> But the BootOrder in Sunny's case may require a partial protection, which means portion of the variable buffer needs to
> be read-only.
> Today's variable policy proposal doesn't take this into consideration.
> If we could enhance variable policy to support partial protection, @Sunny can you please check whether it can meet your
> requirement?
> 
> The enhancement I think of is: Introduce two fields to the policy structure Offset and Length.
> Offset (-1) indicates a whole variable protection.
> Offset (>= 0) indicates a partial variable protection and the protection range starts from Offset with Length bytes.
> 
> This enhancement is also useful when some policy fields inside a big policy structure needs to be read-only.
> Protecting multiple discontinuous ranges of  a variable can be achieved by adding multiple policy entries with different
> Offset/Length.
> 
> 
> Thanks,
> Ray
> 
> > -----Original Message-----
> > From: announce at edk2.groups.io <announce at edk2.groups.io> On Behalf Of
> > Ni, Ray
> > Sent: Friday, February 21, 2020 5:17 PM
> > To: announce at edk2.groups.io
> > Subject: [edk2-announce] TianoCore Community Design Meeting Minutes -
> > Feb 21, 2020
> >
> > OPEN:
> >   Today's meeting is using Zoom because of the long latency using BlueJeans.
> >   The URL to join meeting is changed. Make sure to check https://edk2.groups.io/g/devel/calendar  for details.
> >   We will try Zoom for next meeting as well. If everything is good, we will continue to use Zoom.
> >
> > 1. Platform Libraries for Supporting UEFI Variable Resiliency (HPE)
> > Presenter: Sunny Wang
> > Slides:
> > INVALID URI REMOVED
> > devel_files_Designs_2020_0221_Platform-2520Libraries-2520for-2520Suppo
> > rting-2520UEFI-2520Variable-25&d=DwIFAg&c=C5b8zRQO1miGmBeVZ2LFWg&r=Z9c
> > LgEMdGZCI1_R0bW6KqOAGzCXLJUR24f8N3205AYw&m=U5okqrn3H585vxU4GwALnIBwi0s
> > 0dQ0hYIDuFj2z-4Y&s=oG0quXKBZu3XD7Drm04CsF445C8kfOGOJGzeqACJxAA&e=
> > 20Resiliency.pdf
> >
> > Problem: Support UEFI variable resiliency to compliant to security
> > related guidelines and requirements. #page 2
> >
> > Locking BootOrder causes issues in OSes which is not acceptable.
> > EDKII is lack of interfaces for adding platform variable protection.
> > Today's presentation is to propose a solution.
> > Basic rule of how variable resiliency manages BootOrder changes: #5-#6
> > - Put down untrusted changes
> > - Keep trusted changes
> >
> > @Mike: Where is the reference data stored?
> > @Sunny: In BMC.
> >
> > <Can variable policy protocol help?>
> > @Mike: Would like to see a small enhancement in variable policy protocol proposed by Microsoft to meet your case.
> > @Sunny: I checked the variable policy proposal by Microsoft. Using that might be complicated.
> > @Sean: We (Microsoft) have looked this. Variable hook in DXE phase not
> > in SMM is a security hole. Don't like the way of managing BootOrder by
> > allowing OS to change BootOrder and reverting. Boot#### may contain critical data for OS and reverting that may cause
> troubles.
> > @Sunny: I cannot think of solutions for OS runtime change.
> >
> > <Problem discussion>
> > @Mike: I would break the big problem to 3 smaller ones:
> >    1. variable data corruption
> >         It requires a way to detect corruption and recovery.
> >    2. critical platform variables
> >         It usually requires a lock mechanism and variable policy proposal is more general for this protection.
> >    3. UEFI variables with multiple producers
> >         How to protect them could be a topic for USWG.
> > @Sean: The scope of the problem discussed in this presentation is
> > huge. Can a platform module run at a different point of time to manage the variable storage instead of using hook way?
> > @Sunny: BootOrder is just one of the variables that need protection.
> >
> > <Can using a separate platform module instead of hooking help?>
> > @Mike: Using a separate platform module might be better because it
> > will also check the variables not changed by firmware.
> > @Sean: PEI modules may access the wrong data modified by untrusted entity.
> > @Ray: Is the protection based on not just the variable GUID/name, but also who requests the change?
> > @Sunny: Yes. Following sides (#page 10+) will talk about protection from non-trusted entity.
> > @Ray: Let's move to email discussion first. Identify the scope of the problem first.
> >
> > Thanks,
> > Ray
> >
> >
> 
> 
> 
> 
> 
> 


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