fwupd/plugins/uefi-dbx
Richard Hughes c4bc709359 Do not use help2man to build manual pages
This prevents problems when cross compiling. Using help2man is now also of
limited use; if we can just tell the user to use --help we do not need to keep
the manual in sync.

It also allows us to drop the several other supporting files that we use when
the help2man output isn't actually that useful.

Fixes https://github.com/fwupd/fwupd/issues/3025
2021-04-11 13:42:04 +01:00
..
fuzzing uefi-dbx: Add a plugin that analyses the UEFI dbx variable 2020-05-07 16:59:36 +01:00
dbxtool.1 Do not use help2man to build manual pages 2021-04-11 13:42:04 +01:00
fu-dbxtool.c Remove FuFirmwareImage and just use FuFirmware instead 2021-03-09 21:14:12 +00:00
fu-efi-image.c Add fu_bytes_get_data_safe() to check for zero sized data 2021-04-10 13:20:07 +01:00
fu-efi-image.h uefi-dbx: Validate the dbx update is safe to apply 2020-08-17 15:59:02 +01:00
fu-plugin-uefi-dbx.c Use FWUPD_COMPILATION define to indicate an in tree build 2021-01-22 14:01:25 -06:00
fu-self-test.c libfwupdplugin: Subclass FuFirmware in FuEfiSignatureList 2021-01-05 14:45:31 +00:00
fu-uefi-dbx-common.c Remove FuFirmwareImage and just use FuFirmware instead 2021-03-09 21:14:12 +00:00
fu-uefi-dbx-common.h libfwupdplugin: Subclass FuFirmware in FuEfiSignatureList 2021-01-05 14:45:31 +00:00
fu-uefi-dbx-device.c Remove FuFirmwareImage and just use FuFirmware instead 2021-03-09 21:14:12 +00:00
fu-uefi-dbx-device.h uefi-dbx: Allow updating the dbx using the LVFS 2020-08-14 13:22:53 +01:00
meson.build Do not use help2man to build manual pages 2021-04-11 13:42:04 +01:00
README.md Add a new internal flag to opt-in to GUID matching 2021-02-25 15:47:25 +00:00

UEFI dbx Support

Introduction

Updating the UEFI revocation database prevents starting EFI binaries with known security issues, and is typically no longer done from a firmware update due to the risk of the machine being "bricked" if the bootloader is not updated first.

This plugin also checks if the UEFI dbx contains all the most recent revoked checksums. The result will be stored in an security attribute for HSI.

Firmware Format

The daemon will decompress the cabinet archive and extract a firmware blob in EFI_SIGNATURE_LIST format.

See https://www.uefi.org/sites/default/files/resources/UEFI%20Spec%202_6.pdf for details.

This plugin supports the following protocol ID:

  • org.uefi.dbx

GUID Generation

These devices use the GUID constructed of the uppercase SHA256 of the X509 certificates found in the system KEK and optionally the EFI architecture. e.g.

  • UEFI\CRT_{sha256}
  • UEFI\CRT_{sha256}&ARCH_{arch}

...where arch is typically one of IA32, X64, ARM or AA64

Update Behavior

The firmware is deployed when the machine is in normal runtime mode, but it is only activated when the system is restarted.

Vendor ID Security

The vendor ID is hardcoded to UEFI:Microsoft for all devices.

External interface access

This plugin requires:

  • read/write access to /sys/firmware/efi/efivars