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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:

What organization or people are asking to have this signed?

uib gmbh - we are the developers of opsi. uib gmbh Bonifaziusplatz 1b 55118 Mainz https://www.uib.de

What product or service is this for?

opsi is an open source operating system provisioning and software deployment framework. We want to deploy Windows with support for SecureBoot and therefore request a signing of our SHIM. This SHIM contains ourt company key. With this key we will sign the following data and enable an easy to use way to deploy SecureBoot via opsi.

What's the justification that this really does need to be signed for the whole world to be able to boot it?

opsi is used to deploy operating systems on a large amount of devices. It would be a disadvantage to manually deploy a key on all SecureBoot enabled machines, especially when a customer has a couple hundreds or even more than throusand machines. Therefore we request a signed SHIM to further sign the rets of our deployment with our key, which is included in the shim, to ease the deployment process.

Why are you unable to reuse shim from another distro that is already signed?

We are using a self compiled Linux Kernel and Miniroot. To boot with secure boot enabled, shim needs to know the certificate of the CA used to sign the kernel image.

Who is the primary contact for security updates, etc.?

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: Erol Ülükmen
  • Position: CEO
  • Email address: e.ueluekmen@uib.de
  • PGP key fingerprint: 9083B7BB221D5E6578E3450D06DA6B5DFD200AAE
  • PGP key id: 0x06DA6B5DFD200AAE

(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.)

Who is the secondary contact for security updates, etc.?

  • Name: Mathias Radtke
  • Position: Developer
  • Email address: m.radtke@uib.de
  • PGP key fingerprint: D905656EDA12972F39FD9EB64719E3A9F93C6B3C
  • PGP key id: 0x4719E3A9F93C6B3C

(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.)

Were these binaries created from the 15.8 shim release tar?

Please create your shim binaries starting with the 15.8 shim release tar file: https://github.com/rhboot/shim/releases/download/15.7/shim-15.8.tar.bz2

This matches https://github.com/rhboot/shim/releases/tag/15.8 and contains the appropriate gnu-efi source.

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:

https://github.com/opsi-org/shim-review

What patches are being applied and why:

dell_netboot_fix.patch has been added to fix a bug appearing on some Dell devices. The issue leads to non booting devices via TFTP. More on this issue can be read here: rhboot/shim#649

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)

Upstream GRUB2 shim_lock verifier

If shim is loading GRUB2 bootloader and your previously released shim booted a version of GRUB2 affected by any of the CVEs in the July 2020, the March 2021, the June 7th 2022, the November 15th 2022, or 3rd of October 2023 GRUB2 CVE list, have fixes for all these CVEs been applied?

Yes, all fixed for the above CVEs have been applied

If these fixes have been applied, is the upstream global SBAT generation in your GRUB2 binary set to 4?

The entry should look similar to: grub,4,Free Software Foundation,grub,GRUB_UPSTREAM_VERSION,https://www.gnu.org/software/grub/

Yes

Were old shims hashes provided to Microsoft for verification and to be added to future DBX updates?

Does your new chain of trust disallow booting old GRUB2 builds affected by the CVEs?

Old shim hashes have been provided to microsoft Chain of trust disallows booting old GRUB2 builds affected by mentioned CVEs SBAT Version has been incremented to prevent booting old version Shims

If your boot chain of trust includes a Linux kernel:

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?

All of the above commits are implemented in our linux kernel.

Do you build your signed kernel with additional local patches? What do they do?

No

Do you use an ephemeral key for signing kernel modules?

If not, please describe how you ensure that one kernel build does not load modules built for another kernel.

Yes

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.

no vendor_db functionality in use

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.

Please describe your strategy.

no vendor_db functionality in use as SBAT version has been increased with review #360

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.

No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 22.04.1 LTS
Release:	22.04
Codename:	jammy

ii  binutils                              2.38-4ubuntu2.6                         amd64        GNU assembler, linker and binary utilities
ii  gcc                                   4:11.2.0-1ubuntu1                       amd64        GNU C compiler
ii  gcc-10-base:amd64                     10.5.0-1ubuntu1~22.04                   amd64        GCC, the GNU Compiler Collection (base package)
ii  gcc-11                                11.4.0-1ubuntu1~22.04                   amd64        GNU C compiler
ii  gcc-11-base:amd64                     11.4.0-1ubuntu1~22.04                   amd64        GCC, the GNU Compiler Collection (base package)
ii  gcc-11-multilib                       11.4.0-1ubuntu1~22.04                   amd64        GNU C compiler (multilib support)
ii  gcc-12-base:amd64                     12.3.0-1ubuntu1~22.04                   amd64        GCC, the GNU Compiler Collection (base package)
ii  gcc-9                                 9.5.0-1ubuntu1~22.04                    amd64        GNU C compiler
ii  gcc-9-base:amd64                      9.5.0-1ubuntu1~22.04                    amd64        GCC, the GNU Compiler Collection (base package)
ii  gcc-multilib                          4:11.2.0-1ubuntu1                       amd64        GNU C compiler (multilib files)
ii  lib32gcc-11-dev                       11.4.0-1ubuntu1~22.04                   amd64        GCC support library (32 bit development files)
ii  lib32gcc-s1                           12.3.0-1ubuntu1~22.04                   amd64        GCC support library (32 bit Version)
ii  libgcc-11-dev:amd64                   11.4.0-1ubuntu1~22.04                   amd64        GCC support library (development files)
ii  libgcc-9-dev:amd64                    9.5.0-1ubuntu1~22.04                    amd64        GCC support library (development files)
ii  libgcc-s1:amd64                       12.3.0-1ubuntu1~22.04                   amd64        GCC support library
ii  libx32gcc-11-dev                      11.4.0-1ubuntu1~22.04                   amd64        GCC support library (x32 development files)
ii  libx32gcc-s1                          12.3.0-1ubuntu1~22.04                   amd64        GCC support library (x32)
ii  gnu-efi                               3.0.13+git20210716.269ef9d-2ubuntu1     amd64        Library for developing EFI applications

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.

https://github.com/opsi-org/shim-review/blob/master/build.log

What changes were made since your SHIM was last signed?

added dell_netboot_fix.patch to fix issue rhboot/shim#649

What is the SHA256 hash of your final SHIM binary?

9c447ae6ee1010eb19645c9479cb47c35eb4afab8b3b36eda586112c1a68c19e

How do you manage and protect the keys used in your SHIM?

The token we use is a Hardware Token provided by our EV Certificate Issuer (Globalsign). Our signing key for the Secure Boot binaries is stored on this token, next to our EV certificate. The EV certificate itself was used to initially sign the testfile for Microsoft when joining the Microsoft Developers Program for the UEFI submissions and is NOT used to sign Kernel or Grub2 images. The Secure Boot keys are used to sign our Kernel and Grub2 images. Those Secure Boot keys match the embedded CA Cert in our shim submission. This token is only used on this one machine. We run automated build processes for Grub2 binaries and Linux Kernel builds. After the automated build is complete the artifacts are published on an internal only file server. We then download those files on the sign machine, enter the token password and sign the files with the aforementioned Secure Boot keys. Those signed files are then uploaded to the file server again. Afterwards an automated process takes over to create a package with those signed files, along with other files.

Do you use EV certificates as embedded certificates in the SHIM?

No

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.

If you are using a downstream implementation of GRUB2 (e.g. from Fedora or Debian), please preserve the SBAT entry from those distributions and only append your own. More information on how SBAT works can be found here.

shim
sbat,1,SBAT Version,sbat,1,https://github.com/rhboot/shim/blob/main/SBAT.md
shim,4,UEFI shim,shim,1,https://github.com/rhboot/shim
shim.opsi,4,opsi,shim,15.8,https://opsi.org

grub
sbat,1,SBAT Version,sbat,1,https://github.com/rhboot/shim/blob/main/SBAT.md
grub,4,Free Software Foundation,grub,2.12-rc1,https://www.gnu.org/software/grub/
grub.opsi,4,opsi,grub2,2.12,https://opsi.org`

Which modules are built into your signed grub image?

all_video cat chain configfile echo exfat ext2 fat font gfxmenu gfxterm_background gfxterm halt http iso9660 lvm memdisk minicmd msdospart normal ntfs ntfscomp part_apple part_gpt part_msdos password password_pbkdf2 pbkdf2 png read reboot regexp scsi search serial sleep smbios tftp time tar test true video efifwsetup efinet linuxefi biosdisk gzio search_fs_file linux net pxe

What is the origin and full version number of your bootloader (GRUB or other)?

grub2-2.12

If your SHIM launches any other components, please provide further details on what is launched.

It doesn't

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.

It doesn't

How do the launched components prevent execution of unauthenticated code?

grub2 verifies signatures on booted kernels via shim.

Does your SHIM load any loaders that support loading unsigned kernels (e.g. GRUB)?

No, it boots GRUB only.

What kernel are you using? Which patches does it includes to enforce Secure Boot?

linux, various versions. Starting with 6.6.X. They include lockdown patches & ACPI patches, lockdown is enforced when booted with SecureBoot, config enforces kernel module signatures under lockdown.

Add any additional information you think we may need to validate this shim.

[your text here]

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