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 tag
- approval is ready when the "accepted" label is added to your issue
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.
Check the docs directory in this repo for guidance on submission and getting your shim signed.
Here's the template:
EgoSecure Full Disk Encryption by Matrix42
What's the justification that this really does need to be signed for the whole world to be able to boot it?
EgoSecure Full Disk Encryption secures data on laptops by applying sector level encryption with Pre-boot authentication. We need to be signed because we want to distribute our product to our end users across the world. Our Pre-boot authentication has to support Secure Boot. We have used a Microsoft SecureBoot signed Shim since 2018.
We have updated our vendor certificate bacuse the previous certificate has expired.
The security contacts need to be verified before the shim can be accepted. For subsequent requests, contact verification is only necessary if the security contacts or their PGP keys have changed since the last successful verification.
An authorized reviewer will initiate contact verification by sending each security contact a PGP-encrypted email containing random words.
You will be asked to post the contents of these mails in your shim-review issue to prove ownership of the email addresses and PGP keys.
- Name: Andrei Voicu
- Position: Engineering Manager
- Email address: andrei.voicu@matrix42.com
- PGP key fingerprint: 1B96BC60FA8B9EF41B6A39DE7FC3A7600FCA2CEF
(Key should be signed by the other security contacts, pushed to a keyserver like keyserver.ubuntu.com, and preferably have signatures that are reasonably well known in the Linux community.)
- Name: Bogdan Ariton
- Position: Software Engineer
- Email address: bogdan.ariton@matrix42.com
- PGP key fingerprint: 25EC754AFA008273926CBEA6D6E8CDDF488D0131
(Key should be signed by the other security contacts, pushed to a keyserver like keyserver.ubuntu.com, and preferably have signatures that are reasonably well known in the Linux community.)
Please create your shim binaries starting with the 15.7 shim release tar file: https://github.com/rhboot/shim/releases/download/15.7/shim-15.7.tar.bz2
This matches https://github.com/rhboot/shim/releases/tag/15.7 and contains the appropriate gnu-efi source.
Yes, we use 15.7 shim release https://github.com/rhboot/shim/releases/download/15.7/shim-15.7.tar.bz2
https://github.com/rhboot/shim/releases/tag/15.7
We need to check if "loader_str" is an actual path or not Reason for the patch: Because our shim is replacing the windows boot loader: bootmgfw.efi, the paramters sent to windows boot loader cannot be considered a path to secondary boot loader. Our default boot loader is set while building the shim.
If shim is loading GRUB2 bootloader what exact implementation of Secureboot in GRUB2 do you have? (Either Upstream GRUB2 shim_lock verifier or Downstream RHEL/Fedora/Debian/Canonical-like implementation)
GRUB bootloader is not used
If shim is loading GRUB2 bootloader and your previously released shim booted a version of grub affected by any of the CVEs in the July 2020 grub2 CVE list, the March 2021 grub2 CVE list, the June 7th 2022 grub2 CVE list, or the November 15th 2022 list, have fixes for all these CVEs been applied?
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CVE-2020-14372
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CVE-2020-25632
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CVE-2020-25647
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CVE-2020-27749
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CVE-2020-27779
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CVE-2021-20225
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CVE-2021-20233
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CVE-2020-10713
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CVE-2020-14308
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CVE-2020-14309
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CVE-2020-14310
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CVE-2020-14311
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CVE-2020-15705
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CVE-2021-3418 (if you are shipping the shim_lock module)
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CVE-2021-3695
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CVE-2021-3696
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CVE-2021-3697
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CVE-2022-28733
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CVE-2022-28734
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CVE-2022-28735
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CVE-2022-28736
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CVE-2022-28737
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CVE-2022-2601
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CVE-2022-3775
GRUB bootloader is not used
GRUB bootloader is not used
Our earlier software versions continue to employ the previous build shim, and it is not possible to include it as a DBX exception. We have also SBAT support. GRUB bootloader is not used.
Is upstream commit 1957a85b0032a81e6482ca4aab883643b8dae06e "efi: Restrict efivar_ssdt_load when the kernel is locked down" applied?
Is upstream commit 75b0cea7bf307f362057cc778efe89af4c615354 "ACPI: configfs: Disallow loading ACPI tables when locked down" applied?
Is upstream commit eadb2f47a3ced5c64b23b90fd2a3463f63726066 "lockdown: also lock down previous kgdb use" applied?
We are currently running Kernel version 5.5.7. Our intention is to upgrade to the latest kernel version and apply the most recent security patches. However, our current priority is to address the issue involving a certificate mismatch under the shim. Resolving this problem is crucial for unblocking our clients.
It's worth noting that we only utilize the Linux kernel to display a login dialog for user authentication, allowing them to proceed to boot into Windows. We do not grant shell access or permit any actions that involve modifying kernel modules or similar activities.
We build and sign linux kernel locally. No additional local patches.
If not, please describe how you ensure that one kernel build does not load modules built for another kernel.
We do not employ ephemeral keys. Our practice does not involve granting shell access to the kernel. Instead, we utilize a minimal kernel configuration with a login dialog exclusively for user authentication purposes.
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 don't use hashes to verify our own efi binaries. We use VENDOR_CERT_FILE with one certificate that will be used to verify all our efi binaries.
If you are re-using a previously used (CA) certificate, you will need to add the hashes of the previous GRUB2 binaries exposed to the CVEs 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.
We're changing to a new CA certificate. GRUB bootloader is not used.
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 closely 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 what the differences would be.
Please use the included file 'Dockerfile' to reproduce build
This should include logs for creating the buildroots, applying patches, doing the build, creating the archives, etc.
build.log
Update shim version to 15.7
We're not making changes to the shim, we download the source and build it using the option for VENDOR_CERT_FILE and DEFAULT_LOADER.
We're updating the vendor EV certificate because the last certificate has expired.
50501d79a8ecc1648ed4418e5a35207feb08b797f4387ab1876e7e29abdc0b51 (sha256sum shim.efi)
The private key, associated with the vendor EV certificate build with the shim, is saved on an Hardware Security Module that is attached and only available to our internal build machine.
Yes.
Do you add a vendor-specific SBAT entry to the SBAT section in each binary that supports SBAT metadata ( grub2, fwupd, fwupdate, shim + all child shim binaries )?
Please provide exact SBAT entries for all SBAT binaries you are booting or planning to boot directly through shim.
Where your code is only slightly modified from an upstream vendor's, please also preserve their SBAT entries to simplify revocation.
shim.egosecure,1,Matrix42 GmbH,shim,15.7,https://matrix42.com
GRUB bootloader is not used.
GRUB bootloader is not used. We have a custom boot loader.
The shim loads our custom loader (the DEFAULT_LOADER provided to the shim). We use a custom second-stage loader. According to business logic, the loader can start Microsoft Windows Boot Manager or own Linux Kernel image. All of the files we load are code-signed with the EV vendor certificate provided to the shim. To start the loader we create our own EFI boot entry.
If your GRUB2 launches any other binaries that are not the Linux kernel in SecureBoot mode, please provide further details on what is launched and how it enforces Secureboot lockdown.
GRUB bootloader is not used.
All our components are signed with our vendor EV certificate.
No.
Linux kernel 5.5.7, which has the all the required patches to enforce the secure boot.
We are currently running Kernel version 5.5.7. Our intention is to upgrade to the latest kernel version and apply the most recent security patches. However, our current priority is to address the issue involving a certificate mismatch under the shim. Resolving this problem is crucial for unblocking our clients.
It's worth noting that we only utilize the Linux kernel to display a login dialog for user authentication, allowing them to proceed to boot into Windows. We do not grant shell access or permit any actions that involve modifying kernel modules or similar activities.
file: shim.efi
sha256: 50501d79a8ecc1648ed4418e5a35207feb08b797f4387ab1876e7e29abdc0b51