Signed manifest for run-time verification of software program identity and integrity

• US 20070005992A1
• Filed: 06/30/2005
• Published: 01/04/2007
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Schluessler, Travis, Cox, George, Durham, David, Grewal, Karanvir
• Granted Patent: US 7,953,980 B2
• Time in Patent Office: Days
• US Class Current: 713/193
• CPC Class Codes: G06F 21/54 by adding security routines or objects to programs
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 63/126 the source of the received data
• CPC Class Codes: H04L 63/20 for managing network security; network security policies in general filtering policies H04L63/0227
• CPC Class Codes: H04L 9/004 for fault attacks
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions

Abstract

A measurement engine performs active platform observation. A program includes an integrity manifest to indicate an integrity check value for a section of the program'"'"'s source code. The measurement engine computes a comparison value on the program'"'"'s image in memory and determines if the comparison value matches the expected integrity check value. If the values do not match, the program'"'"'s image is determined to be modified, and appropriate remedial action can be triggered. The integrity manifest can include a secure signature to verify the validity of the integrity manifest.

Claims

1. A method comprising:

generating an integrity check value on a section of a software program loaded from a storage into a memory;

comparing the generated integrity check value to an expected value; and

determining that the section of the software program has been modified if the generated integrity check value and the expected value do not match.

2. A method according to claim 1, wherein the section of the program comprises one or more of code, static configuration data, or dynamic configuration data.

3. A method according to claim 1, wherein generating the integrity check value and comparing the generated integrity check value to the expected value comprise periodically generating an integrity check value and comparing the periodically generated integrity check value to an expected value.

4. A method according to claim 1, wherein generating the integrity check value comprises generating the integrity check value in response to the occurrence of an integrity check event.

5. A method according to claim 4, wherein the integrity check event comprises one or more of:

a configuration parameter change, a data packet transmission, or termination of the execution of the agent.

6. A method according to claim 1, wherein comparing the generated integrity check value to the expected value comprises comparing the generated integrity check value to a result of a cryptographic hash of a section of an image of the software program in storage corresponding to the section for which the integrity check value was generated.

7. A method according to claim 1, further comprising:

alerting an administrator over an out-of-band communication link if the generated integrity check value and the expected value do not match.

8. A method according to claim 1, further comprising:

determining a memory address relocation value used to fix-up function calls in the code section when the section of the software program is loaded into the memory;

wherein generating the integrity check value on the section further comprises offsetting the physical memory address of function calls in an image of the section with the memory address relocation value and generating the integrity check value on the image.

9. A method according to claim 8, wherein determining the memory address relocation value comprises storing a base address offset used by a program loader.

10. A method according to claim 8, further comprising:

storing the generated integrity check value as the expected value for a subsequent integrity check value comparison.

11. A method according to claim 1, wherein the expected value comprises a value generated on the code store of the program prior to loading the program into the memory.

12. A method according to claim 1, wherein the expected value comprises a value from a group of integrity check values compiled as a datastructure having a signature.

13. A method according to claim 12, wherein the signature comprises the result of a cryptographic hash based at least in part on a private key of an asymmetric key pair.

14. An article of manufacture comprising a machine accessible medium having content to provide instructions which, when executed, result in the performance of operations including:

loading a known good integrity check value into a memory local to a measurement engine;

computing an algorithm on a portion of an agent in a system memory to generate an integrity check value for the agent in system memory;

comparing the generated integrity check value with the known good integrity check value to determine if the integrity check values match; and

reporting an error condition if the integrity check values do not match.

15. An article of manufacture according to claim 14, further comprising the content to provide instructions to result in:

determining for a dynamically assigned address referenced within the agent a memory address offset as applied to the dynamically assigned address in conjunction with loading the agent into the system memory;

wherein computing the algorithm to generate the integrity check value on the portion of the agent comprises reversing the offset to determine a pre-offset value for the dynamically assigned address referenced within the agent, and computing the algorithm on the portion of the agent with the pre-offset value.

16. An article of manufacture according to claim 15, wherein the dynamically assigned address referenced within the agent comprises a dynamically addressed function call.

17. An article of manufacture according to claim 14, further comprising the content to provide instructions to result in:

halting execution of the software program if the generated integrity check value and the expected value do not match.

18. An apparatus comprising:

a memory with an image of a software agent having an integrity manifest, the integrity manifest including a relocation fix-up to indicate an offset value to redirect an operation within the software agent to a particular physical memory location, and an identity test value derived from the source code of the software agent;

a processor coupled to the memory to execute the software agent; and

an active management module coupled to the memory to derive an additional identity test value from the image of the software agent in memory, compare the identity test value derived from the image in memory to the identity test value derived from the source code, and indicate an agent identification failure if the identity test values do not match.

19. An apparatus according to claim 18, wherein the software agent comprises one of:

a device driver, an operating system invariant, or a security module.

20. An apparatus according to claim 19, wherein the operating system invariant comprises one of:

a loader or a symbol table.

21. An apparatus according to claim 19, wherein the security module comprises one of:

a software firewall, an intrusion detection system, or an antivirus program.

22. An apparatus according to claim 18, the active management module coupled to the memory comprising a service processor of the active management module having a direct memory access interface to the memory.

23. A system comprising:

a memory having instructions thereon to implement a software program, the software program having an integrity manifest with a relocation fix-up including a physical memory offset value, and an integrity check value representing the result of a cryptographic hash of a section of the software program source code from which the instructions come;

a service processor coupled to the memory to compare a cryptographic hash of a section of the instructions corresponding to the section of the software program source code to the integrity check value to determine if the instructions in the memory are altered from the source code, and indicate if the instructions in the memory are altered;

a network interface coupled to the service processor having an out-of-band communication channel between the service processor and a remote administrator; and

a twisted pair communication line coupled to the network interface to transmit the indication of whether the instructions in the memory are altered.

24. A system according to claim 23, wherein the physical memory offset value comprises the actual physical memory offset applied to function calls within the source code when the software program was loaded into the memory, and wherein to compare the cryptographic hash of the section of the instructions to the integrity check value further comprises reverting the address of the function calls to the pre-offset memory address prior to performing the cryptographic hash on the section of instructions.

25. A system according to claim 24, further comprising the service processor to store the result of the cryptographic hash on the section of the instructions as the integrity check value for a subsequent comparison.

26. A method comprising:

generating an integrity check value on a section of a software program; and

storing the generated integrity check value with the software program to be used as an expected value to verify an image of the software program as loaded into a system memory.

27. A method according to claim 26, further comprising signing the integrity check value with a hash function based at least in part on a cryptographic key, the result of the hash to be stored with the integrity check value with the software program.

28. A method according to claim 26, further comprising:

generating a test integrity check value on a section of the software program loaded from a storage into the system memory;

comparing the generated test integrity check value to the expected value; and

determining that the section of the software program has been modified if the generated integrity check value and the expected value do not match.