Protected computing environment

• US 9,189,605 B2
• Filed: 02/23/2009
• Issued: 11/17/2015
• Est. Priority Date: 04/22/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Barde, Sumedh N., Schwartz, Jonathan D., Kuhn, Reid Joseph, Grigorovitch, Alexandre Vicktorovich, Debique, Kirt A., Knowlton, Chadd B., Alkove, James M., Dunbar, Geoffrey T., Grier, Michael J., Ma, Ming, Upadhyay, Chaitanya D., Sherwani, Adil Ahmed, Kishan, Arun Upadhyaya
• Primary Examiner(s): Popham, Jeffrey D
• Application Number:
  US12/390,505
• Publication Number:
  US 20090158036A1
• Time in Patent Office: 2,458 Days
• Field of Search: 713/164
• US Class Current: 1/1
• CPC Class Codes: G06F 21/1064 Restricting content processing at operating system level
• CPC Class Codes: G06F 21/57 Certifying or maintaining trusted computer platforms, e.g. secure boots or power-downs, version controls, system software checks, secure updates or assessing vulnerabilities
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 9/3247 involving digital signatures
• 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

A method of establishing a protected environment within a computing device including validating a kernel component loaded into a kernel of the computing device, establishing a security state for the kernel based on the validation, creating a secure process and loading a software component into the secure process, periodically checking the security state of the kernel, and notifying the secure process when the security state of the kernel has changed.

Claims

1. A method of loading a plurality of kernel components to create a secure computing environment within a computing device, the method comprising:

loading, by a kernel loader of the plurality of kernel components of a kernel of an operating system of the computing device, a protected environment (“

PE”

) management component into the kernel, where the loaded PE management component is operational on the computing device, where the PE management component is one of the plurality of kernel components, and where the kernel loader is operational on the computing device;

validating, by the loaded and operational PE management component, that the operational kernel loader is secure, the validating based on a valid signature of the operational kernel loader;

determining that a debugger is coupled to the computing device; and

determining that a debug credential that corresponds to the debugger indicates that debugging via the debugger is authorized on the computing device with the secure computing environment.

2. The method of claim 1, further comprising setting, based on the debug credential, a kernel secure flag.

3. The method of claim 1, further comprising:

loading a revocation list into the kernel of the operating system;

determining that there is another component of the plurality of kernel components to load into the kernel;

validating a signature of the another component;

verifying that a certificate of the another component is valid;

determining that the signature is not on the loaded revocation list; and

determining that the certificate in not on the loaded revocation list.

4. The method of claim 3, further comprising:

determining that the signature is acceptable for use;

determining that the certificate is acceptable for use; and

loading, in response to the determinings, the validating, and the verifying, the another component into the kernel.

5. A computer comprising:

a memory;

an operating system including a kernel that includes a plurality of kernel components;

a kernel loader configured for loading a protected environment (“

PE”

) management component into the kernel, where the kernel loader and the PE management component are each being one of the plurality of kernel components;

the protected environment (“

PE”

) management component configured for validating that the kernel loader is secure based on a valid signature of the operational kernel loader; and

a kernel secure flag maintained in the kernel and configured to indicate, in response to the validating, that the computer is allowed to load a trusted application into the memory, and where the kernel secure flag is further configured to indicate, in response to the validating, that the computer is not allowed to load the trusted application into the memory.

6. The system of claim 5 further comprising a revocation list.

7. At least one storage device that is not a signal per se, the at least one storage device storing computer-executable instruction that, when executed by a computer, cause the computer to perform a method of loading a plurality of kernel components to create a protected environment (“

PE”

), the method comprising;

loading, by a kernel loader of the plurality of kernel components of a kernel of an operating system of the computer, a PE management component into the kernel, where the loaded PE management component is operational on the computer, where the PE management component is one of the plurality of kernel components, and where the kernel loader is operational on the computer;

validating, by the loaded and operational PE management component, that the operational kernel loader is secure based on a valid signature of the operational kernel loader;

determining that a debugger is coupled to the computer; and

determining that a debug credential that corresponds to the debugger indicates that debugging via the debugger is authorized on the computer computing device with the protected environment.

8. The at least one storage device of claim 7, the method further comprising setting, based on the debug credential, the kernel secure flag.

9. The at least one storage device of claim 7, the method further comprising:

loading a revocation list into the kernel;

determining that there is another component to load into the kernel;

validating a signature of the another component of the plurality of kernel components;

verifying that a certificate associated with the component is valid;

determining that the signature is not on the loaded revocation list; and

determining that the certificate in not on the loaded revocation list.

10. The at least one storage device of claim 9, the method further comprising:

determining that the signature is acceptable for use;

determining that the certificate is acceptable for use; and

loading, in response to the determinings, the validating, and the verifying, the loaded component into the kernel.