This repo is for review of requests for signing shim. To create a request for review:
- clone this repo
- edit the template below
- add the shim.efi to be signed
- add build logs
- add any additional binaries/certificates/SHA256 hashes that may be needed
- commit all of that
- tag it with a tag of the form “myorg-shim-arch-YYYYMMDD”
- push that to github
- file an issue at https://github.com/rhboot/shim-review/issues with a link to your branch
- approval is ready when you have accepted tag
Note that we really only have experience with using GRUB2 on Linux, so asking us to endorse anything else for signing is going to require some convincing on your part.
Here's the template:
What organization or people are asking to have this signed:
What product or service is this for:
Chrome OS (reven board)
What's the justification that this really does need to be signed for the whole world to be able to boot it:
Chrome OS is a Linux distribution. We want to enable (and encourage) our user base to boot Chrome OS (reven) with secure boot enabled.
Who is the primary contact for security updates, etc.
Who is the secondary contact for security updates, etc.
Please create your shim binaries starting with the 15.4 shim release tar file: https://github.com/rhboot/shim/releases/download/15.4/shim-15.4.tar.bz2
We can confirm that all of our shim binaries are built from the referenced tarball.
URL for a repo that contains the exact code which was built to get this binary:
What patches are being applied and why:
We are applying the following patches to fix critical regressions that have been identified in shim 15.4:
https://github.com/rhboot/shim/pull/364 https://github.com/rhboot/shim/pull/362 https://github.com/rhboot/shim/pull/357 https://github.com/rhboot/shim/pull/361
If bootloader, shim loading is, GRUB2: is CVE-2020-14372, CVE-2020-25632, CVE-2020-25647, CVE-2020-27749, CVE-2020-27779, CVE-2021-20225, CVE-2021-20233, CVE-2020-10713, CVE-2020-14308, CVE-2020-14309, CVE-2020-14310, CVE-2020-14311, CVE-2020-15705, and if you are shipping the shim_lock module CVE-2021-3418
We're using upstream GRUB2
What exact implementation of Secureboot in GRUB2 ( if this is your bootloader ) you have ?
- Upstream GRUB2 shim_lock verifier or * Downstream RHEL/Fedora/Debian/Canonical like implementation ?
Upstream GRUB2 shim_lock verifier
If bootloader, shim loading is, GRUB2, and previous shims were trusting affected by CVE-2020-14372, CVE-2020-25632, CVE-2020-25647, CVE-2020-27749, CVE-2020-27779, CVE-2021-20225, CVE-2021-20233, CVE-2020-10713, CVE-2020-14308, CVE-2020-14309, CVE-2020-14310, CVE-2020-14311, CVE-2020-15705, and if you were shipping the shim_lock module CVE-2021-3418 ( July 2020 grub2 CVE list + March 2021 grub2 CVE list ) grub2:
- were old shims hashes provided to Microsoft for verification and to be added to future DBX update ?
- Does your new chain of trust disallow booting old, affected by CVE-2020-14372, CVE-2020-25632, CVE-2020-25647, CVE-2020-27749, CVE-2020-27779, CVE-2021-20225, CVE-2021-20233, CVE-2020-10713, CVE-2020-14308, CVE-2020-14309, CVE-2020-14310, CVE-2020-14311, CVE-2020-15705, and if you were shipping the shim_lock module CVE-2021-3418 ( July 2020 grub2 CVE list + March 2021 grub2 CVE list ) grub2 builds ?
If your boot chain of trust includes linux kernel, is “efi: Restrict efivar_ssdt_load when the kernel is locked down” upstream commit 1957a85b0032a81e6482ca4aab883643b8dae06e applied ? Is “ACPI: configfs: Disallow loading ACPI tables when locked down” upstream commit 75b0cea7bf307f362057cc778efe89af4c615354 applied ?
- Yes, 1957a85b0032a81e6482ca4aab883643b8dae06e is applied in our kernel (https://chromium.googlesource.com/chromiumos/third_party/kernel/+/1957a85b0032a81e6482ca4aab883643b8dae06e)
- Yes, 75b0cea7bf307f362057cc778efe89af4c615354 is applied in our kernel (https://chromium.googlesource.com/chromiumos/third_party/kernel/+/75b0cea7bf307f362057cc778efe89af4c615354)
If you use vendor_db functionality of providing multiple certificates and/or hashes please briefly describe your certificate setup. If there are allow-listed hashes please provide exact binaries for which hashes are created via file sharing service, available in public with anonymous access for verification
We do not use this functionality.
If you are re-using a previously used (CA) certificate, you will need to add the hashes of the previous GRUB2 binaries to vendor_dbx in shim in order to prevent GRUB2 from being able to chainload those older GRUB2 binaries. If you are changing to a new (CA) certificate, this does not apply. Please describe your strategy.
We are changing to a new certificate.
What OS and toolchain must we use to reproduce this build? Include where to find it, etc. We‘re going to try to reproduce your build as close as possible to verify that it’s really a build of the source tree you tell us it is, so these need to be fairly thorough. At the very least include the specific versions of gcc, binutils, and gnu-efi which were used, and where to find those binaries. If the shim binaries can‘t be reproduced using the provided Dockerfile, please explain why that’s the case and the differences would be.
All shim binaries can be built using our Dockerfile and instructions in the README.md of https://chromium.googlesource.com/external/github.com/neverware/shim-build/+/refs/tags/v8
Which files in this repo are the logs for your build? This should include logs for creating the buildroots, applying patches, doing the build, creating the archives, etc.
Add any additional information you think we may need to validate this shim
We made our initial shim submissions as Neverware (see https://github.com/rhboot/shim-review/issues/27 and https://github.com/rhboot/shim-review/issues/106). We had a recent shim submission as Google approved for CloudReady (https://github.com/rhboot/shim-review/issues/193). This submission is for the project as it will be built on Google infrastructure, switching to the chromeos/reven identifier.