Detecting corruption in a computer program at execution time using a checksum
AssigneeMicrosoft Corporation
InventorsBenjamin W. Slivka, Chuck Strouss
Life of this patent
Estimating the term…
Abstract
A mechanism for detecting corruption of computer programs is provided. In a preferred embodiment of the present invention, a checksum is used to determine when a computer program has been corrupted. Upon initially starting a computer program, a first checksum is calculated for the computer program. When the computer program is requested to perform an operation, a second checksum is calculated for the computer program. Corruption of the computer program is indicated when the first checksum does not equal the second checksum.
Claims21
A method in a computer system for detecting corruption of a computer program, the computer system having a memory containing the computer program, wherein the computer program receives requests to perform operations and performs the operations, comprising the steps of:
- loading the computer program into the memory;
- initiating execution of the computer program;
- during the execution of the computer program,
- calculating a first checksum for the computer program, for each of a plurality of requests,
- receiving the request to perform an operation by the computer program;
- calculating a second checksum for the computer program in response to said step of receiving the request to perform the operation by the computer program;
- and
- comparing the first checksum to the second checksum wherein when the first checksum does not equal the second checksum, then the computer program has been corrupted.
A method in a computer system for detecting corruption in an operating system, the computer system having a memory containing the operating system, wherein the operating system receives requests to perform operations and performs the operations, the operating system having contents, comprising the steps of:
- loading the operating system into the memory;
- initiating execution of the operating system;
- during the execution of the operating system,
- creating a first identifier based on the contents of the operating system;
- for each of plurality of requests,
- receiving the request to perform an operation by the operating system;
- creating a second identifier based on the contents of the operating system in response to the received request;
- and
- comparing the first identifier to the second identifier wherein when the first identifier does not equal the second identifier, then the operating system has been corrupted.
A method in a computer system for performing an operation in a computer program, the computer system having a memory containing the computer program, the computer program having a data section and a code section, wherein the computer program receives requests to perform operations and wherein the computer program performs operations which access the code section and the data section, comprising the steps of:
- loading the computer program into the memory;
- initiating execution of the computer program;
- during the execution of the computer program,
- calculating a first data checksum for the data section of the computer program;
- calculating a first code checksum for the code section of the computer program;
- for each of a plurality of requests,
- receiving the request to perform an operation;
- determining if performing the operation will access the code section and the data section;
- if performing the operation will access the code section of the computer program then,
- calculating a second code checksum for the code section of the computer program;
- and
- comparing the first code checksum to the second code checksum wherein if the first code checksum does not equal the second code checksum, then the code section of the computer program has been corrupted;
- and
- if performing the operation will access the dam section of the computer program,
- calculating a second data checksum for the data section of the computer program;
- and
- comparing the first data checksum to the second data checksum wherein if the first data checksum does not equal the second data checksum, then the data section of the computer program has been corrupted.
A computer system comprising:
- a processor for executing a computer program;
- a memory containing the computer program that is being executed by the processor for receiving requests to perform operations and for performing the operations;
- means for receiving a request to perform an operation by the computer program;
- a checksum component for calculating a first checksum on the computer program before receiving a request to perform an operation and for calculating a second checksum on the computer program after receiving the request to perform the operation while the computer program is executing;
- and
- a comparison component for comparing the first checksum and the second checksum in response to receiving the request to perform the operation by the computer program and for indicating that the first checksum does not equal the second checksum.
A method in a computer system for detecting corruption of a computer program, the computer system having a memory containing the computer program, comprising the steps of:
- loading the computer program into the memory;
- initiating execution of the computer program;
- during the execution of the computer program,
- calculating a first checksum for the computer program;
- determining when a periodic interval has expired;
- and
- when it is determined that the periodic interval has expired,
- calculating a second checksum for the computer program;
- and
- comparing the first checksum to the second checksum wherein when the first checksum does not equal the second checksum, then the computer program has been corrupted.
A method in a computer system for detecting corruption of a computer program, the computer system having a memory containing the computer program, comprising the steps of:
- loading the computer program into the memory;
- initiating execution of the computer program;
- during the execution of the computer program,
- under the control of the computer program,
- calculating a first checksum for the computer program;
- determining when a periodic interval has expired;
- and
- when the computer program determines that the periodic interval has expired,
- calculating a second checksum for the computer program;
- and
- comparing the first checksum to the second checksum, wherein the first checksum does not equal the second checksum, then the computer program has been corrupted.
A method in a computer system for detecting corruption of a computer program, the computer program having a descriptor, wherein the computer program receives requests to perform operations and performs the operations, comprising the steps of:
- loading the computer program into the memory;
- initiating execution of the computer program;
- during the execution of the computer program,
- creating a first descriptor based on the contents of the computer program;
- for each of a plurality of requests,
- receiving the request to perform an operation by the computer program;
- creating a second descriptor based on the contents of the computer program in response to the step of receiving the request;
- and
- comparing the first descriptor to the second descriptor, wherein when the first descriptor does not equal the second descriptor, then the computer program has been corrupted.
Dependencies are inferred from the claim text.