Systems and methods for establishing core root of trust measurement (CRTM) for basic input/output (BIOS) image recovery
Systems and methods for establishing Core Root of Trust Measurement (CRTM) for Basic Input/Output (BIOS) image recovery are described. In some embodiments, an Information Handling System (IHS) may include a processor and a BIOS coupled to the processor, the BIOS having program instructions that, upon execution, cause the IHS to: during a boot process, verify integrity of a BIOS recovery image using a CRTM, and determine whether to restore the BIOS recovery image in response to the verification.
1. An information Handling System (IHS), comprising:
a processor; and
a memory containing a Basic Input/Output System (BIOS) coupled to the processor, the BIOS comprising program instructions that, upon execution, cause the IHS to:
during a boot process, verify integrity of a BIOS recovery image using a Core Root of Trust Measurement (CRTM);
determine whether to restore the BIOS recovery image in response to the verification, wherein the BIOS includes a first pre-efi initialization phase (PEI) portion and a first Driver Execution Environment (DXE)/System Management Mode (SMM) portion, and wherein the BIOS recovery image includes a second DXE/SMM portion; and
verify the integrity of the first PEI portion using a hardware Root of Trust, wherein the program instructions, upon execution, further cause the first PEI portion to chain the CRTM to the second DXE/SMM portion to verify the second DXE/SMM portion.
2. The IHS of claim 1 , wherein the program instructions, upon execution, further cause the IHS to:
detect changes in the BIOS recovery image; and
prevent the IHS from booting.
3. The IHS of claim 1 , wherein the program instructions, upon execution, further cause the IHS to:
detect no changes in the BIOS recovery image; and
allow the IHS to boot.
4. The IHS of claim 1 , wherein the program instructions, upon execution, further cause the first PEI portion to compare a DXE measurement of the second DXE/SMM portion with a known value stored in the first PEI portion.
5. The IHS of claim 4 , wherein the known value includes a value stored in a Platform Configuration Register (PCR) prior to initiation of the restore.
6. The IHS of claim 4 , wherein the program instructions, upon execution, further cause the IHS to write contents of the second DXE/SMM portion to a Serial Peripheral Interface (SPI) module.
7. The IHS of claim 4 , wherein the program instructions, upon execution, further cause the IHS to:
verify the DXE/SMM contents on the SPI; and
in response to the verification, hand off execution to the second DXE/SMM portion on the SPI module.
8. A memory containing a Basic I/O System (BIOS) comprising program instructions that, upon execution by an information Handling System (IHS), cause the IHS to:
during a boot process, verify integrity of a BIOS recovery image using a Core Root of Trust Measurement (CRTM), wherein the BIOS includes a first pre-efi initialization phase (PEI) portion and a first Driver Execution Environment (DXE)/System Management Mode (SMM) portion, and wherein the BIOS recovery image includes a second DXE/SMM portion;
determine whether to restore the BIOS recovery image in response to the verification;
verify the integrity of the first PEI portion using a hardware Root of Trust, wherein the program instructions, upon execution, further cause the first PEI portion to chain the CRTM to the second DXE/SMM portion to verify the second DXE/SMM portion.
9. The BIOS of claim 8 , wherein the program instructions, upon execution, further cause the first PEI portion to compare a DXE measurement of the second DXE/SMM portion with a known value stored in the first PEI portion.
10. The BIOS of claim 9 , wherein the program instructions, upon execution, further cause the IHS to write contents of the second DXE/SMM portion to a Serial Peripheral Interface (SPI) module.
11. The BIOS of claim 10 , wherein the program instructions, upon execution, further cause the IHS to:
verify the DXE/SMM contents on the SPI; and
in response to the verification, hand off execution to the second DXE/SMM portion on the SPI module.
12. In an Information Handling System (IHS) comprising a memory containing a Basic I/O System (BIOS) coupled to a processor, a method comprising:
during a boot process, verifying integrity of a BIOS recovery image using a Core Root of Trust Measurement (CRTM), wherein the BIOS includes a first pre-efi initialization phase (PEI) portion and a first Driver Execution Environment (DXE)/System Management Mode (SMM) portion, and wherein the BIOS recovery image includes a second DXE/SMM portion;
determining whether to restore the BIOS recovery image in response to the verification; and
verifying the integrity of the first PEI portion using a hardware Root of Trust, and causing the first PEI portion to chain the CRTM to the second DXE/SMM portion.
13. The method of claim 12 , wherein the program instructions, upon execution, further cause the first PEI portion to compare a DXE measurement of the second DXE/SMM portion with a known value stored in the first PEI portion, and to write contents of the second DXE/SMM portion to a Serial Peripheral Interface (SPI) module.
14. The method of claim 13 , further comprising verify the DXE/SMM contents on the SPI; and in response to the verification, handing off execution to the second DXE/SMM portion on the SPI module.