System and method for trusted early boot flow

• US 20060224878A1
• Filed: 03/31/2005
• Published: 10/05/2006
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Zimmer, Vincent J., Rothman, Michael A., Datta, Shamanna M.
• Granted Patent: US 7,752,428 B2
• Time in Patent Office: Days
• US Class Current: 713/2
• CPC Class Codes: G06F 21/575 Secure boot
• CPC Class Codes: H04L 9/32 including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials
• CPC Class Codes: H04L 9/3234 involving additional secure or trusted devices, e.g. TPM, smartcard, USB or software token network architectures or network communication protocols for supporting authentication of entities using an additional device in a packet data network H04L63/0853

Abstract

In some embodiments, the invention involves extending trusted computing environments to the boot firmware. In at least one embodiment, the present invention is intended to enable the trusted environment to be extended forward to the pre-boot environment in addition to post-OS load environment. Embodiments of the present invention enable the trusted environment to extend to the firmware at power-on. The firmware is integrated within the secure perimeter which was previously only available to the OS. In other words, the BIOS is made to be a trusted entity, as well as the OS. Extensible firmware interface (EFI) modules are signed with a public key. The processor has an embedded private key. EFI modules are verified using the keys to ensure a trusted environment from boot to OS launch. Other embodiments are described and claimed.

Claims

1. A platform comprising:

a processor utilizing security management extension (SMX) instructions and having a private key, the processor communicatively coupled to firmware comprising one or more authenticated code (AC) modules;

the one or more AC modules comprising a header, instruction code, and data, and further comprising a public key,

wherein the public and private key enable AC modules to be trusted in execution during initialization prior to launch of an operating system.

2. The platform as recited in claim 1 wherein the processor architecture comprises an extensible firmware interface (EFI).

3. The platform as recited in claim 2, wherein the one or more AC modules further comprise:

a firmware file header;

an optional name;

an image section; and

an optional dependency expression section.

4. The platform as recited in claim 2, wherein the private key is embedded in the processor.

5. The platform as recited in claim 2, further comprising:

processor microcode to load an AC module manager upon boot up, the AC module manager to load a pre-EFI (PEI) foundation and commence dispatch of the one or more AC modules.

6. The platform as recited in claim 5, wherein the AC module manager is a security (SEC) module.

7. The platform as recited in claim 6, wherein the SEC module is loaded into cache as random access memory (CRAM), the cache being coupled to the processor.

8. The platform as recited in claim 5, wherein a first SMX instruction is executed prior to loading the AC module manager, and wherein the first SMX instruction enables an AC module to be authenticated using the public and private keys.

9. The platform as recited in claim 8, wherein a second SMX instruction is executed by an AC module to enable execution to resume by the AC module manager or one of the one or more AC modules.

10. The platform as recited in claim 2, wherein platform initialization occurs during a pre-EFI (PEI) initialization stage of boot up, the pre-EFI initialization stage comprising initialization of the processor, platform chipset and platform motherboard, and wherein PEI comprises execution of the one or more AC modules, the AC modules being authenticated by the public and private keys, and wherein PEI ensures a trusted environment through loading of a trusted operating system.

11. The platform as recited in claim 10, wherein the firmware services initialized during PEI are trusted by the trusted operating system

12. A method for enabling a trusted environment in a platform comprising:

authenticating one or more authenticated code (AC) modules during initialization of a platform prior to launch of an operating system, wherein the authenticated AC modules ensure trusted platform firmware services available to a trusted operating system; and

loading authenticated AC modules to perform various initialization tasks.

13. The method as recited in claim 12, wherein authenticating comprises:

using a private key embedded in a processor on the platform and a public key encoded within the one or more AC modules; and

aborting initialization if authentication fails.

14. The method as recited in claim 12, wherein authenticating and loading of the one or more AC modules in enabled by security management extension (SMX) instructions implemented in the platform'"'"'s instruction set architecture (ISA).

15. The method as recited in claim 12, wherein the platform comprises an extensible firmware interface (EFI) architecture and initialization is at a pre-EFI initialization (PEI) phase of execution.

16. The method as recited in claim 15, wherein authenticating and loading of the one or more AC modules in enabled by security management extension (SMX) instructions implemented in the platform'"'"'s instruction set architecture (ISA), and further comprising:

if the platform has multiple processors, issuing a first SMX instruction by an initiating logical processor (ILP) to suspend operations by one or more responding logical processors (RLPs);

if the platform has multiple processors, responding by the RLPs to indicate that the issued SMX instruction has been acknowledged prior to loading authenticated AC modules;

launching an authenticated and loaded AC module comprising a PEI core module;

repeating the authenticating, loading and launching for successive AC modules until PEI initialization succeeds or fails;

if PEI initialization succeeds, issuing a second SMX instruction by an initiating logical processor (ILP) to resume and join operations by the one or more RLPs; and

if the PEI initialization fails, aborting boot up of the platform.

17. A machine accessible medium having instructions that when executed cause the machine to:

authenticate one or more authenticated code (AC) modules during initialization of a platform prior to launch of an operating system, wherein the authenticated AC modules ensure trusted platform firmware services on the machine, the trusted platform firmware services available to a trusted operating system; and

load authenticated AC modules to perform various initialization tasks.

18. The machine accessible medium as recited in claim 17, wherein authenticating further comprises instructions that cause the machine to:

use a private key embedded in a processor on the machine and a public key encoded within the one or more AC modules; and

abort initialization if authentication fails.

19. The machine accessible medium as recited in claim 17, wherein authenticating and loading of the one or more AC modules in enabled by a security management extension (SMX) instructions implemented in the machine'"'"'s instruction set architecture (ISA).

20. The machine accessible medium as recited in claim 17, wherein the machine comprises an extensible firmware interface (EFI) architecture and initialization is at a pre-EFI initialization (PEI) phase of execution.

21. The machine accessible medium as recited in claim 20, wherein authenticating and loading of the one or more AC modules in enabled by security management extension (SMX) instructions implemented in the machine'"'"'s instruction set architecture (ISA), and wherein the medium further comprises instructions that when executed cause the machine to:

if the platform has multiple processors, issue a first SMX instruction by an initiating logical processor (ILP) to suspend operations by one or more responding logical processors (RLPs);

if the platform has multiple processors, respond by the RLPs to indicate that the issued SMX instruction has been acknowledged prior to loading authenticated AC modules;

launch an authenticated and loaded AC module comprising a PEI core module;

repeat the authenticating, loading and launching for successive AC modules until PEI initialization succeeds or fails;

if PEI initialization succeeds, issue a second SMX instruction by an initiating logical processor (ILP) to resume and join operations by the one or more RLPs; and

if the PEI initialization fails, abort boot up of the platform.