Binding by hash

• US 7,124,408 B1
• Filed: 06/28/2000
• Issued: 10/17/2006
• Est. Priority Date: 06/28/2000
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Sinclair, Craig T., Parthasarathy, Srivatsan, Pratschner, Steven J.
• Primary Examiner(s): Chaki, Kakali
• Assistant Examiner(s): VU, TUAN A
• Application Number:
  US09/604,987
• Time in Patent Office: 2,302 Days
• Field of Search: 717162-166, 713/187, 713/191, 713/193, 713/156, 713/176, 713/200, 713/167, 709/102, 709/106, 709/315, 709/316, 709/320, 709/332
• US Class Current: 717/170
• CPC Class Codes: G06F 21/51 at application loading time, e.g. accepting, rejecting, starting or inhibiting executable software based on integrity or source reliability
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 2221/2145 Inheriting rights or properties, e.g., propagation of permissions or restrictions within a hierarchy
• CPC Class Codes: G06F 9/44521 Dynamic linking or loading; Link editing at or after load time, e.g. Java class loading
• CPC Class Codes: G06F 9/4494 data driven

Abstract

A system and method is provided for providing security to components or assemblies employed by application programs during runtime. Assemblies carry version information that can be used to enforce the versioning rules described by the application program. At runtime, version numbers requested by the application programs are compared with those version numbers of the assemblies that are actually found. In addition to comparing version numbers, the present invention offers a stricter form of version checking based on cryptographic hashes. An assembly is provided with module information that contains a list of the files that make up the assembly. Part of the information recorded about each module is a hash of the module'"'"'s contents at the time the manifest was built. An assembly referencing another assembly computes the hash of the manifest of the referenced assembly. An assembly manifest may include dependency information, which is information about other assemblies that the assembly depends on or references. Part of the information stored as part of an assembly reference or manifest is a hash of the dependent assembly'"'"'s manifest.

Claims

1. A method for facilitating integrity of an assembly employable by application programs during runtime, comprising:

providing an assembly with an assembly manifest that contains a list of modules that make up the assembly;

providing the assembly manifest with a hash of the contents of at least one module of the list of modules;

providing the assembly manifest with a hash of a manifest of at least one other assembly that the assembly depends on; and

comparing the hash retained in the assembly manifest with a hash of the at least one module obtained at runtime to identify whether a runtime version of the at least one module is substantially similar to a version utilized at build time of the assembly and utilizing said identification to evaluate the integrity of the assembly.

2. The method of claim 1, providing the assembly manifest with the hash of the contents of at least one module of the list of modules comprises providing the assembly manifest with a hash of each module of the list of modules that constitutes the assembly.

3. The method of claim 1, further comprising providing identity information in the assembly manifest.

4. The method of claim 3, the identity information comprising publisher information and version information.

5. The method of claim 1, further comprising providing a hash of the contents of the assembly at the end of the assembly.

6. The method of claim 1, further comprising determining if the contents of the assembly have been modified by determining an actual hash of the contents of the at least one module of the list of modules and comparing the actual hash with the hash of the contents of the at least one module of the list of modules residing in the assembly manifest.

7. The method of claim 6, further comprising determining if the publisher of the assembly is trustworthy if the assembly has been modified.

8. The method of claim 7, determining if the publisher of the assembly is trustworthy if the assembly has been modified comprises checking version information and publisher name information residing in the assembly manifest.

9. A method for facilitating integrity of assemblies employable by application programs during runtime, comprising:

providing an assembly with an assembly manifest that contains a list of referenced assemblies that the assembly depends on;

providing the assembly manifest with a hash of a manifest of at least one referenced assembly of the list of referenced assemblies; and

analyzing the hash provided to the assembly manifest and a second hash of the manifest of the at least one referenced assembly computed at runtime to determine whether changes have been made to the at least one referenced assembly between runtime and at build time of the assembly and utilizing said determination to evaluate the integrity of the assembly.

10. The method of claim 9, providing the assembly manifest with the hash of the manifest of at least one referenced assembly of the list of referenced assemblies comprises providing the assembly manifest with a hash of each referenced assembly of the list of referenced assemblies.

11. The method of claim 9, further comprising providing identity information in the assembly manifest.

12. The method of claim 11, the identity information comprising publisher information and version information.

13. The method of claim 9, further comprising providing a hash of the contents of the assembly at the end of the assembly.

14. The method of claim 9, further comprising determining if the contents of the at least one referenced assembly have been modified by determining an actual hash of the contents of the at least one referenced assembly of the list of referenced assemblies and comparing the actual hash with a hash of the contents of the at least one referenced assembly of the list of referenced assemblies residing in the assembly manifest.

15. The method of claim 14, further comprising determining if the publisher of the at least one referenced assembly is trustworthy if the at least one referenced assembly has been modified.

16. The method of claim 15, determining if the publisher of the at least one referenced assembly is trustworthy if the at least one referenced assembly has been modified comprises checking version information and publisher name information residing in the manifest of the at least one referenced assembly.

17. A computer readable medium having at least one computer executable component employable by an application program at runtime comprising:

an assembly including an assembly manifest that contains a list of at least one referenced assembly that the assembly references, a first hash of a manifest of the at least one referenced assembly, a list of modules that make up the assembly and a hash of the contents of at least one module of the list of modules, the hash of the contents of the at least one module is utilized to control which versions of the modules are employed in connection with the assembly at runtime;

a component that compares the first hash to a second hash produced at runtime and utilizes the determination as to whether the at least one referenced assembly is a same version as the at least one referenced assembly utilized at build time of the assembly to evaluate the integrity of the assembly.

18. The computer readable medium of claim 17, the assembly manifest including identity information and version information.

19. The computer readable medium of claim 17, the assembly being a dynamically linked library.

20. A computer readable medium having at least one computer executable component employable by an application program at runtime comprising:

an assembly including an assembly manifest that contains a list of at least one referenced assembly that the assembly references and a hash of a manifest of the at least one referenced assembly;

a component that compares the hash to a second hash produced at runtime and utilizes the determination as to whether the at least one referenced assembly is a same version as the at least one referenced assembly utilized at build time of the assembly to evaluate the integrity of the assembly.

21. A computer implemented system for facilitating integrity of assemblies employable by application programs at runtime, the system comprising:

a first component that provides an assembly manifest for an assembly, the assembly manifest having a list of modules making up the assembly and a list of at least one referenced assembly that the assembly references;

a second component that provides the assembly manifest with a hash of at least one module of the list of modules and a hash of a manifest of the at least one referenced assembly; and

a third component that compares the hash of the at least one module with a hash of the at least one module generated at runtime to identify changes in the content of the at least one module; and

utilizes said identification to evaluate the integrity of the assembly.

22. The system of claim 21, further comprising a third component adapted to compare the hash of said at least one module with an actual hash value of the at least one module.

23. The system of claim 22, the assembly manifest including identity and version information and the third component adapted to determine if the assembly should be executed based on a review of the originator and version information, if the hash of the at least one module in the assembly manifest and the actual hash value of the at least one module are different.

24. The system of claim 21, further comprising a binding component adapted to provide binding policy information for determining a version of an assembly that an application program will run if another assembly having the same name resides on the system.

25. A computer implemented system for facilitating integrity of assemblies employable by application programs at runtime, the system comprising:

a first component that provides an assembly manifest for an assembly, the assembly manifest having at least one referenced assembly, the at least one referenced assembly comprising a manifest;

a second component that provides the assembly manifest with a hash of the manifest of the at least one referenced assembly; and

a third component that compares the hash of the at least one referenced assembly in the assembly manifest with an actual hash value of the at least one referenced assembly to identify version changes and utilizes said identification to evaluate the integrity of the assembly.

26. The system of claim 25, further comprising a binding component adapted to provide the third component with binding policy information.

27. A computer implemented system for facilitating integrity of an assembly employable by application programs at runtime, the system comprising:

means for relating an assembly manifest having a list of at least one related assembly to an assembly, the at least one related assembly comprising a manifest;

means for providing the assembly manifest with a hash of the manifest of the at least one related assembly; and

means for evaluating integrity of the assembly by comparing the hash value with a hash value of a second related assembly computed at runtime.

28. The system of claim 27, the at least one related assembly being a module.

29. The system of claim 27, the at least one related assembly being a referenced assembly.

30. The system of claim 27, further comprising means for comparing a hash value of the at least one related assembly in the assembly manifest to an actual hash value of the at least one related assembly.

31. The system of claim 27, further comprising means for establishing a binding policy.

32. The system of claim 27, at least one of the assembly and the at least one related assembly being a dynamically linked library.