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Dasharo Security: Boot Guard support

BGS001.001 Boot Guard support (Ubuntu 22.04)

Test description

Intel Boot Guard is a hardware-based technology intended to protect the device against executing non-genuine firmware, which could happen when a possible attacker has bypassed protection against modification of BIOS. This test aims to verify that the implemented Boot Guard mechanism works correctly.

Test configuration data

  1. FIRMWARE = Dasharo
  2. OPERATING_SYSTEM = Ubuntu 22.04

Test setup

  1. Proceed with the Generic test setup: firmware.
  2. Proceed with the Generic test setup: OS installer.
  3. Proceed with the Generic test setup: OS installation.
  4. Proceed with the Generic test setup: OS boot from disk.
  5. Download cbmem from the cloud to the DUT.
  6. Disable Secure Boot.

Test steps

  1. Power on the DUT.
  2. Boot into the system.
  3. Log into the system by using the proper login and password.
  4. Open a terminal window and execute the following command:

    sudo ./cbmem -1 | grep CBnT
  5. Analyze the output from the command.

Expected result

The output of the command should indicate the state of the Boot Guard.

Example output:

CBnT: SACM INFO MSR (0x13A) raw: 0x000000130000007d
CBnT:   NEM status:                 1
CBnT:   TPM type:                   TPM 2.0
CBnT:   TPM success:                1
CBnT:   FACB:                       1
CBnT:   measured boot:              1
CBnT:   verified boot:              1
CBnT:   revoked:                    0
CBnT:   BtG capable:                1
CBnT:   Server TXT capable:         0
CBnT: BOOTSTATUS (0xA0) raw: 0x1840000080000000
CBnT:   TXT startup success:        0
CBnT:   BtG startup success:        1
CBnT:   Block boot enabled:         0
CBnT:   PFR startup success:        0
CBnT:   Memory power down executed: 0
CBnT:   BtG thread sync failed:     0
CBnT:   Bios trusted:               1
CBnT:   TXT disabled by policy:     1
CBnT:   Bootguard startup error:    0
CBnT:   TXT ucode or ACM error:     0
CBnT:   S-ACM success:              0
CBnT: ERRORCODE (0x30) raw: 0x00000000
CBnT: TXT disabled in Policy
CBnT: BIOSACM_ERRORCODE (0x328) raw: 0xc000acf0
CBnT:   AC Module Type:          BIOS ACM Error
CBnT:   class:                   0xf
CBnT:   major:                   0xb
CBnT:   External:                0x1

During the analyzing process, the main thing is to pay attention to the following:

  1. The field NEM status should have the value 1.
  2. If the Boot Guard profile is 4 or 5, the field FACB should have the value 1.
  3. If the Boot Guard profile is 3 or 5, the fields measured boot and verified boot should have the value 1.
  4. If TPM is physically mounted on the platform, the TPM type field should contain information about the type of the mounted TPM; also, in that situation, field TPM success should have the value 1.