File language verification

• US 7,506,175 B2
• Filed: 11/05/2001
• Issued: 03/17/2009
• Est. Priority Date: 11/06/2000
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Baentsch, Michael, Oestreicher, Marcus, Buhler, Peter, Eirich, Thomas, Hoering, Frank, Weigold, Thomas D.
• Primary Examiner(s): Vu; Kim
• Assistant Examiner(s): PATEL, NIRAV B
• Application Number:
  US09/992,984
• Publication Number:
  US 20020093856A1
• Time in Patent Office: 2,689 Days
• Field of Search: 713187-189, 713/165, 713/164, 713/166, 713/167, 713/190, 713/192, 713/193, 713/176, 713/178, 717124-126, 717/114, 717/117, 717106-108, 717/139, 717142-144, 717/118, 717/138, 717/148, 726 22- 24, 726/26, 707/1, 718/1
• US Class Current: 713/187
• CPC Class Codes: G06F 9/44589 Program code verification, e.g. Java bytecode verification, proof-carrying code high-level semantic checks G06F8/43; testing and debugging software G06F11/36
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00

Abstract

A technique for language verification of a Java® card CAP file is provided. The Java® card CAP file is converted from an original Java® code file while conserving its original Java® semantics. The Java® card CAP file is converted into a corresponding converted Java® code file that is semantically identical to the Java® card CAP file. In a language-verification step, the converted Java® code file is then verified if it has been found to comply with a predetermined language specification.

Claims

1. A computer-implemented method of verifying that a reduced set of code adheres to a pre-defined language syntax before being stored in a smart card, the computer-implemented method comprising:

determining if an original full-version code file complies with a pre-defined language syntax, wherein the original full-version code file is capable of executing all instructions and utilizing all features found in a full version of a programming language;

in response to determining that the original full-version code file complies with the pre-defined language syntax, creating a first cryptographic signature for the original full-version code file;

storing the first cryptographic signature on a smart card, wherein the smart card comprises a limited-capacity embedded microcontroller;

converting the original full-version code file into a reduced-version code file, wherein the reduced-version code file is capable of executing only a limited subset of instructions and features found in the full version of the programming language;

converting the reduced-version code file into a converted file, wherein the converted file is capable of utilizing all features found in the full version of the programming language, and wherein converting the reduced-version code file into the converted file is performed by a pre-conversion step, a mapping step, and a final conversion step,

wherein the pre-conversion step includes;

converting the reduced-version code file into a preconverted file, wherein the preconverted file utilizes the pre-defined language syntax, and

wherein the preconverted file includes a preconverted code section and a preconverted code description section, and

wherein the mapping step includes;

utilizing a mapper to replace, in the preconverted file, externally defined names in the reduced-version code file with original names that are used in the full-version code file, wherein the mapper utilizes an export file that was created during the pre-conversion step, and wherein external references found in the preconverted file are resolved and converted into symbolic external reference for every class file that is referenced by the reduced-version code file, and

wherein the final conversion step includes;

converting the preconverted file into the converted file by rearranging individual code sections, header sections and link information so that they comply with the pre-defined language syntax, wherein the converted file includes a converted class description and converted executable instructions that are respectively derived from the preconverted code section and the preconverted code description section in the preconverted file;

in response to determining that the converted file complies with the pre-defined language syntax, creating a second cryptographic signature for the converted file;

storing the second cryptographic signature on the smart card; and

in response to the first cryptographic signature matching the second cryptographic signature, storing the reduced-version code file on the smart card, wherein the first cryptographic signature and the second cryptographic signature match only if the original full-version code file, the reduced-version code file, the preconverted file, and the converted file all comply with the pre-defined language syntax.

2. The computer-implemented method of claim 1, wherein the converted file contains a different class file than the original full-version code file, but wherein the converted file and the original full-version code file are semantically identical according to syntax rules set by the pre-defined language syntax.

3. The computer-implemented method of claim 2, wherein creating and comparing the first cryptographic signature and the second cryptographic signature are performed outside the smart card.

4. A tangible computer-readable medium on which is stored a computer program code, the computer program code comprising computer executable instructions configured for verifying that a reduced set of code adheres to a pre-defined language syntax before being loaded onto a smart card, and wherein the computer executable instructions, when executed, perform the steps of:

determining if an original full-version code file complies with a pre-defined language syntax, wherein the original full-version code file is capable of executing all instructions and utilizing all features found in a full version of a programming language;

in response to determining that the original full-version code file compiles with the pre-defined language syntax, creating a first cryptographic signature for the original full-version code file;

storing the first cryptographic signature on a smart card, wherein the smart card comprises a limited-capacity embedded microcontroller;

converting the original full-version code file into a reduced-version code file, wherein the reduced-version code file is capable of executing only a limited subset of instructions and features found in the full version of the programming language;

converting the reduced-version code file into a converted file, wherein the converted file is capable of utilizing all features found in the full version of the programming language, and wherein converting the reduced-version code file into the converted file is performed by a pre-conversion step, a mapping step, and a final conversion step,

wherein the pre-conversion step includes;

converting the reduced-version code file into a preconverted file, wherein the preconverted file utilizes the pre-defined language syntax, and

wherein the preconverted file includes a preconverted code section and a preconverted code description section, and

wherein the mapping step includes;

utilizing a mapper to replace, in the preconverted file, externally defined names in the reduced-version code file with original names that are used in the full-version code file, wherein the mapper utilizes an export file that was created during the pre-conversion step, and wherein external references found in the preconverted file are resolved and converted into symbolic external reference for every class file that is referenced by the reduced-version code file, and

wherein the final conversion step includes;

converting the preconverted file into the converted file by rearranging individual code sections, header sections and link information so that they comply with the pre-defined language syntax, wherein the converted file includes a converted class description and converted executable instructions that are respectively derived from the preconverted code section and the preconverted code description section in the preconverted file;

in response to determining that the converted file complies with the pre-defined language syntax, creating a second cryptographic signature for the converted file;

storing the second cryptographic signature on the smart card; and

in response to the first cryptographic signature matching the second cryptographic signature, storing the reduced-version code file on the smart card, wherein the first cryptographic signature and the second cryptographic signature match only if the original full-version code file, the reduced-version code file and the converted file comply with the pre-defined language syntax.

5. The tangible computer-readable medium of claim 4, wherein the converted file contains a different class file than the original full-version code file, but wherein the converted file and the original full-version code file are semantically identical according to syntax rules set by the pre-defined language syntax.

6. The tangible computer-readable medium of claim 5, wherein creating and comparing the first cryptographic signature and the second cryptographic signature are performed outside the smart card.

7. A computer system comprising a tangible computer-readable medium on which is stored a computer program code, the computer program code comprising computer executable instructions configured for verifying that a reduced set of code adheres to a pre-defined language syntax before being loaded onto a smart card, and wherein the computer executable instructions, when executed, perform the steps of:

determining if an original full-version code file complies with a pre-defined language syntax, wherein the original full-version code file is capable of executing all instructions and utilizing all features found in a full version of a programming language;

in response to determining that the original full-version code file complies with the pre-defined language syntax, creating a first cryptographic signature for the original full-version code file;

storing the first cryptographic signature on a smart card, wherein the smart card comprises a limited-capacity embedded microcontroller;

converting the original full-version code file into a reduced-version code file, wherein the reduced-version code file is capable of executing only a limited subset of instructions and features found in the full version of the programming language;

converting the reduced-version code file into a converted file, wherein the converted file is capable of utilizing all features found in the full version of the programming language, and wherein converting the reduced-version code file into the converted file is performed by a pre-conversion step, a mapping step, and a final conversion step,

wherein the pre-conversion step includes;

converting the reduced-version code file into a preconverted file, wherein the preconverted file utilizes the pre-defined language syntax, and

wherein the preconverted file includes a preconverted code section and a preconverted code description section, and

wherein the mapping step includes;

utilizing a mapper to replace, in the preconverted file, externally defined names in the reduced-version code file with original names that are used in the full-version code file, wherein the mapper utilizes an export file that was created during the pre-conversion step, and wherein external references found in the preconverted file are resolved and converted into symbolic external reference for every class file that is referenced by the reduced-version code file, and

wherein the final conversion step includes;

converting the preconverted file into the converted file by rearranging individual code sections, header sections and link information so that they comply with the pre-defined language syntax, wherein the converted file includes a converted class description and converted executable instructions that are respectively derived from the preconverted code section and the preconverted code description section in the preconverted file;

in response to determining that the converted file complies with the pre-defined language syntax, creating a second cryptographic signature for the converted file;

storing the second cryptographic signature on the smart card; and

in response to the first cryptographic signature matching the second cryptographic signature, storing the reduced-version code file on the smart card, wherein the first cryptographic signature and the second cryptographic signature match only if the original full-version code file, the reduced-version code file and the converted file comply with the pre-defined language syntax.

8. The computer system of claim 7, wherein the converted file contains a different class file than the original full-version code file, but wherein the converted file and the original full-version code file are semantically identical according to syntax rules set by the pre-defined language syntax.

9. The computer system of claim 8, wherein creating and comparing the first cryptographic signature and the second cryptographic signature are performed outside the smart card.