Trusted Communications With Child Processes

• US 20120174210A1
• Filed: 03/14/2012
• Published: 07/05/2012
• Est. Priority Date: 07/19/2006
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Dubhashi, Kedarnath Atmaram, Schwartz, Jonathan D., Muthukrishnan, Sambavi, Skaria, Simon
• Granted Patent: US 8,943,579 B2
• Time in Patent Office: Days
• US Class Current: 726/17
• CPC Class Codes: G06F 9/547 Remote procedure calls [RPC]; Web services

Abstract

A method to identify a child process to a parent process in an operating system includes obtaining a token and login identifier from the operating system. The parent process creates a remote procedure call communications endpoint to communicate with the child process. Thereafter, a child process is spawned by the parent process. A child-initiated request to communicate with the parent process is then received by the parent process. In order to verify the identity of the child-initiated request, the parent process impersonates the child process and receives as identifier that identifies the requestor child process. The requestor process identifier and the spawned child identifier are compared. Based on the comparison, the parent process responds to the child-initiated request. In another embodiment, process identifiers are used by the parent process to verify the identity of a child process the requests communication with the parent process.

Claims

1. A computer readable storage medium comprising computer readable instructions for identifying a child process to a parent process, comprising:

instructions for creating a communications endpoint;

instructions for spawning, by the parent process, the child process and passing the communications endpoint to the child process, the child process having a child security identifier;

instructions for receiving a request to communicate with the parent process, the request including a security identifier for the requesting process;

instructions for impersonating the requesting process by the parent process;

instructions for comparing the requesting process with the child security identifier, thereby identifying the requesting process as a child process spawned by the parent process; and

instructions for responding, by the parent process, to the request if the comparison is a match of security identifiers.

2. The computer readable storage medium of claim 1, further comprising instructions for obtaining a token from the operating system, the token obtained by the parent process.

3. The computer readable storage medium of claim 1, further comprising instructions for creating a communications endpoint by the parent process.

4. The computer readable storage medium of claim 1, further comprising instructions for establishing a parent server for processing requests.

5. The computer readable storage medium of claim 1, wherein the operating system provides a security identifier that identifies the requestor process to the parent process.

6. The computer readable storage medium of claim 2, wherein said instructions for obtaining a token from the operating system comprises calling into a security subsystem of the operating system by the parent process and receiving a token containing a logon identifier.

7. The computer readable storage medium of claim 1, wherein said instructions for creating a communications endpoint comprises instructions for creating a remote procedure call (RPC) communications endpoint.

8. The computer readable storage medium of claim 1, wherein said instructions for spawning further comprises instructions for setting, by the parent process, a discretionary access control list that identifies processes allowed to access the child process.

9. The computer readable storage medium of claim 1, wherein only a parent process identity is permitted access to the child process.

10. The computer readable storage medium of claim 1, further comprising:

instructions for receiving, by the parent process, a notification returned by the operating system identifying a termination of child process; and

instructions for refusing communications requests once the child process terminates.

11. The computer readable storage medium of claim 1, wherein the termination notification is returned in a separate thread and the endpoint is closed by the parent process.

12. The computer readable storage medium of claim 1, wherein said instructions for receiving the request comprises instructions for receiving by the parent process a requestor-initiated request for sending and receiving data.

13. The computer readable storage medium of claim 1, wherein said instructions for impersonating the requestor process to the operating system comprises using an application programming interface invoked by the parent process upon the operating system.

14. The computer readable storage medium of claim 1, further comprising instructions for closing the endpoint, by the parent process, if the comparison of security identifiers is not a match.

15. The computer readable storage medium of claim 1, further comprising instructions for repeating said instructions for impersonating, comparing, and responding in response to new requests to communicate with the parent process.

16. A system for identifying a child process to a parent process in an operating system in computer software using a process identifier, the system comprising:

a computing device comprising a processor;

a memory communicatively coupled to said processor when said system is operational;

said memory having stored therein computer instructions that upon execution by the processor cause;

creating a communications endpoint;

spawning, by the parent process, the child process and passing the communications endpoint to the child process wherein access to the child process is limited, the spawning also producing a child process identifier;

receiving a request to communicate with the parent process, the request made to the communications endpoint and including a requestor process identifier;

comparing the requestor process identifier with the spawned child process identifier, thereby identifying the requesting process as the child process spawned by the parent process; and

responding, by the parent process, to the request if the comparison is a match of process identifiers.

17. The system of claim 16, wherein the communications endpoint is created by the parent process, further comprising:

obtaining a token from the operating system, the token obtained by the parent process;

establishing a parent server for process responses; and

querying the operating system, by the parent process, for the spawned child process identifier, the operating system providing the spawned child process identifier;

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18. The system of claim 16, further comprising:

receiving, by the parent process, a notification returned by the child process identifying a terminated child process; and

refusing communications requests with the terminated child process.

19. The system of claim 16, further comprising closing the communications endpoint, by the parent process, if the comparison of process identifiers is not a match.

20. The system of claim 16, wherein if the parent process receives a child process notification corresponding to the child process, the notification received in a separate thread, then the child process is terminated and the parent process subsequently refuses all communication requests from the child process and closes the communications endpoint.