SYSTEM AND METHOD TO SECURE BOOT BOTH UEFI AND LEGACY OPTION ROM'S WITH COMMON POLICY ENGINE

• US 20100169633A1
• Filed: 12/31/2008
• Published: 07/01/2010
• Est. Priority Date: 12/31/2008
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Yao, Jiewen, Kumar, Mohan, Zimmer, Vincent, Cui, Liang, Natu, Mahesh, Long, Qin
• Granted Patent: US 8,694,761 B2
• Time in Patent Office: Days
• US Class Current: 713/2
• CPC Class Codes: G06F 21/575 Secure boot

Abstract

In some embodiments, the invention involves using a policy engine during boot, in the driver execution environment (DXE) phases to authenticate that drivers and executable images to be loaded are authenticated. Images to be authenticated include the operating system (OS) loader. The policy engine utilizes a certificate database to hold valid certificates for third party images, according to platform policy. Images that are not authenticated are not loaded at boot time. Other embodiments are described and claimed.

Claims

1. A system for securely booting a platform, comprising:

a processor coupled to a memory store and communicatively coupled to a trusted platform module component, the trusted platform module to provide platform status to a policy engine executing on the processor;

the policy engine communicatively coupled to a certificate database stored in the memory store, wherein the policy engine is configured to authenticate each of a plurality of images to be loaded during boot of the platform, and when an image is not authenticated, the policy engine to prohibit the unauthenticated image from being loaded and launched during boot.

2. The system as recited in claim 1, wherein the certificate database is configured according to a platform policy and comprises a plurality of certificates, each certificate corresponding to one of a plurality of images that is permitted to be loaded during platform boot.

3. The system as recited in claim 2, wherein each certificate in the certificate database is associated with an image authorized to be loaded, and the certificate further comprises a public key, wherein the policy engine is configured to match the public key with an image identifier signature to verify that the image is authorized to be loaded.

4. The system as recited in claim 2, wherein the certificate database comprises:

a certificate database header; and

a plurality of certificate lists,

wherein each certificate list further comprises;

a certificate list size;

a certificate count;

a certificate type;

a certificate header size;

a certificate size;

a certificate header; and

a plurality of certificates, each certificate having a identifier,

wherein each certificate corresponds to an image authorized to be loaded on the platform.

5. The system as recited in claim 1, wherein the policy engine is to be executed during a driver execution environment phase of a boot on a platform conforming to unified extensible interface architecture.

6. The system as recited in claim 1, wherein the plurality of images to be loaded included an operating system loader.

7. The system as recited in claim 6, wherein when the operating system loader is not authorized, the policy engine to prohibit booting of an operating system.

8. The system as recited in claim 1, wherein the plurality of images to be loaded during boot of the platform conform to one of extensible firmware interface image format and legacy image format.

9. The system as recited in claim 8, wherein an image of the plurality of images comprises one of an option-ROM driver and an operating system loader.

10. The system as recited in claim 1, wherein the certificate database is configured to be initialized and updated by an administrator, wherein administrator authority is to be validated prior to allowing administrator action.

11. The system as recited in claim 10, wherein when an administrator removes policy settings from the certificate database, the policy engine is configured to boot the platform in legacy mode and load all images and drivers without further authentication.

12. A method for securely booting a platform, comprising:

retrieving a boot image to be loaded on a platform;

comparing, by a policy engine, a signature associated with the boot image with a certificate in a certificate database stored in memory coupled to the platform;

when the comparison results in a valid match, allowing the boot image to be loaded on the platform during boot; and

when the comparison results in a failed match, then disallowing the image to be loaded on the platform, during boot.

13. The method as recited in claim 12, further comprising executing the policy engine during a driver execution environment phase of boot on the platform, wherein the platform conforms to a unified extensible interface architecture.

14. The method as recited in claim 12, when the image to be loaded is an operating system loader and the comparison to the certificate database fails, prohibiting launch of an operating system on the platform.

15. The method as recited in claim 12, further comprising:

before initiating a full boot of the platform,

validating authority of an administrator; and

configuring the certificate database by initialization or update by the administrator when the administrator has valid authority.

16. The method as recited in claim 15, wherein when the initializing comprises removing policy settings from the certificate database, booting the platform in legacy mode and loading all images and drivers without further authentication.

17. The method as recited in claim 12, further comprising:

configuring the certificate database according to a platform policy, wherein the certificate database comprises a plurality of certificates, each certificate corresponding to one of a plurality of images that is permitted to be loaded during platform boot.

18. The method as recited in claim 17, further comprising matching a public key in a certificate with an image identifier signature to verify that the image is authorized to be loaded,

wherein each certificate in the certificate database is associated with an image authorized to be loaded, and the certificate further comprises a public key.

19. A computer readable storage medium having instructions for securely booting a platform stored therein, the instructions when executed on a platform cause the platform to:

retrieve a boot image to be loaded on a platform;

compare, by a policy engine, a signature associated with the boot image with a certificate in a certificate database stored in memory coupled to the platform;

when the comparison results in a valid match, allow the boot image to be loaded on the platform during boot; and

when the comparison results in a failed match, then disallow the image to be loaded on the platform, during boot.

20. The medium as recited in claim 19, further comprising instructions to execute the policy engine during a driver execution environment phase of boot on the platform, wherein the platform conforms to a unified extensible interface architecture.

21. The medium as recited in claim 19, when the image to be loaded is an operating system loader and the comparison to the certificate database fails, prohibit launch of an operating system on the platform.

22. The medium as recited in claim 19, further comprising instructions to:

before initiating a full boot of the platform,

validate authority of an administrator; and

configure the certificate database by initialization or update by the administrator when the administrator has valid authority.

23. The medium as recited in claim 22, wherein when the initializing comprises removing policy settings from the certificate database, boot the platform in legacy mode and load all images and drivers without further authentication.

24. The medium as recited in claim 19, further comprising instructions to:

configure the certificate database according to a platform policy, wherein the certificate database comprises a plurality of certificates, each certificate corresponding to one of a plurality of images that is permitted to be loaded during platform boot.

25. The medium as recited in claim 24, further comprising instructions to match a public key in a certificate with an image identifier signature to verify that the image is authorized to be loaded,

wherein each certificate in the certificate database is associated with an image authorized to be loaded, and the certificate further comprises a public key.