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@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of Ni, Ray Sent: Wednesday, March 4, 2020 11:46 AM To: Sean Brogan <sean.bro...@microsoft.com>; Kinney, Michael D <michael.d.kin...@intel.com>; Wang, Sunny (HPS SW) <sunnyw...@hpe.com> Cc: Ni, Ray <ray...@intel.com>; devel@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: annou...@edk2.groups.io <annou...@edk2.groups.io> On Behalf Of > Ni, Ray > Sent: Friday, February 21, 2020 5:17 PM > To: annou...@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 > > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#55356): https://edk2.groups.io/g/devel/message/55356 Mute This Topic: https://groups.io/mt/71718822/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
