CRYPTOGRAPHIC CERTIFICATION OF SECURE HOSTED EXECUTION ENVIRONMENTS

• US 20130151848A1
• Filed: 02/13/2012
• Published: 06/13/2013
• Est. Priority Date: 12/12/2011
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Baumann, Andrew A., Hunt, Galen C., Peinado, Marcus
• Granted Patent: US 9,425,965 B2
• Time in Patent Office: Days
• US Class Current: 713/164
• CPC Class Codes: G06F 21/577 Assessing vulnerabilities and evaluating computer system security
• CPC Class Codes: G06F 2221/034 Test or assess a computer or a system
• CPC Class Codes: H04L 9/3263 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823

Abstract

Implementations for providing a persistent secure execution environment with a hosted computer are described. A host operating system of a computing system provides an encrypted checkpoint to a persistence module that executes in a secure execution environment of a hardware-protected memory area initialized by a security-enabled processor. The encrypted checkpoint is derived at least partly from another secure execution environment that is cryptographically certifiable as including another hardware-protected memory area established in an activation state to refrain from executing software not trusted by the client system.

Claims

1. A method comprising:

initializing, by a security-enabled processor of a computing system, a secure execution environment cryptographically certifiable as including a hardware-protected memory area established in an activation state to refrain from executing software not trusted by a client system, the hardware-protected memory area inaccessible to code that executes outside of the hardware-protected memory area, the hardware-protected memory area executing non-kernel mode code; and

providing, by a host operating system of the computing system, a persistence module executing in the secure execution environment with an encrypted checkpoint, the encrypted checkpoint derived at least partly from another secure execution environment cryptographically certifiable as including another hardware-protected memory area established in an activation state to refrain from executing software not trusted by the client system.

2. The method of claim 1, wherein the encrypted checkpoint is encrypted with a persistence key, wherein the persistence key is sealed, and wherein the method further comprises providing the persistence module with the sealed persistence key.

3. The method of claim 2, wherein the persistence key is sealed with a public key of the client system.

4. The method of claim 2, wherein the persistence key is sealed with a public key of the security-enabled processor.

5. The method of claim 1, wherein the other secure execution environment was established on another computing system, and wherein the providing is performed as part of a migration of the other secure execution environment to the computing system.

6. The method of claim 1, wherein the encrypted checkpoint includes state information of the other protected memory area prior to a shut-down of execution of the other secure execution environment.

7. The method of claim 1, wherein the other secure execution environment was established on the computing system, and wherein the providing is performed as part of a re-creation of the other secure execution environment.

8. Computer-readable media comprising a plurality of programming instructions that are executable by one or more processors to cause a computing system to:

execute a secure execution environment that is cryptographically certifiable as including a hardware-protected memory area that is established in an activation state to refrain from executing software not trusted by a client system, the hardware-protected memory area inaccessible to code that executes outside of the hardware-protected memory area, the hardware-protected memory area configured to execute non-kernel mode code;

provide a persistence module in the secure execution environment with an encrypted checkpoint and a sealed persistence key, the encrypted checkpoint derived at least partly from another secure execution environment that is cryptographically certifiable as including another hardware-protected memory area that includes no software untrusted by the client system.

9. The computer-readable media of claim 8, wherein the persistence key is sealed with a public key of the client system.

10. The computer-readable media of claim 8, wherein the persistence key is sealed with a public key of the security-enabled processor.

11. The computer-readable media of claim 8, wherein the persistence module is configured to transmit the sealed persistence key to the client system, and to cause the persistence module to receive an unsealed persistence key from the client system.

12. The computer-readable media of claim 8, wherein persistence module is configured to unseal the sealed persistence key and to decrypt the encrypted checkpoint using the unsealed persistence key.

13. The computer-readable media of claim 8, wherein the other secure execution environment was established on another computing system, and wherein the encrypted checkpoint and the sealed persistence key are provided as part of a migration of the other secure execution environment to the computing system.

14. The computer-readable media of claim 8, wherein the other secure execution environment was established on the computing system, and wherein the encrypted checkpoint and the sealed persistence key are provided as part of a re-creation of the other secure execution environment.

15. A computing system comprising:

memory;

one or more processors, including a security-enabled processor configured to establish at least a hardware-protected memory area on the memory in an activation state to refrain from executing software not trusted by a client system, the hardware-protected memory area inaccessible to code that executes outside of the hardware-protected memory area, the hardware-protected memory area configured to execute non-kernel mode code; and

a persistence module stored in the protected memory area and executable by the one or more processors to;

receive from a host Operating System a request to persist an execution state of a secure execution environment executing within the protected memory area;

cause, at least partly in response to the request, one or more threads associated with the execution state of the secure execution environment to quiesce;

store state information of the execution state to the protected memory area;

encrypt contents of the protected memory area, including the state information, to form an encrypted checkpoint, the encrypted checkpoint encrypted with a persistence key; and

transmit to persistent storage the encrypted checkpoint and a sealed persistence key, the sealed persistence key derived at least partly from the persistence key.

16. The computing system of claim 15, wherein the persistence key is sealed with a public key of the client system.

17. The computing system of claim 15, wherein the persistence key is sealed with a public key of the security-enabled processor.

18. The computing system of claim 15, wherein the request to persist the execution state is a request to migrate the secure execution environment to another computing system.

19. The computing system of claim 15, wherein the request to persist the execution state is a request to re-create the secure execution environment on the computing system.

20. The computing system of claim 19, wherein the hardware-protected memory area comprises a first hardware-protected memory area, and further comprising another persistence module stored on a second hardware-protected memory area established by the security-enabled processor, the other persistence module configured to:

receive the encrypted checkpoint and the sealed persistence key from persistent storage; and

cause the sealed persistence key to be unsealed and to decrypt the encrypted checkpoint using the unsealed persistence key.