Detecting and preventing noncompliant use of source code

• US 8,819,856 B1
• Filed: 08/06/2012
• Issued: 08/26/2014
• Est. Priority Date: 08/06/2012
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Tiffe, Sven, Conradt, Michael, Brown, Jay
• Primary Examiner(s): Reza, Mohammad W
• Application Number:
  US13/567,483
• Time in Patent Office: 750 Days
• Field of Search: 726/31
• US Class Current: 726/31
• CPC Class Codes: G06F 21/12 Protecting executable software
• CPC Class Codes: G06F 21/125 by manipulating the program code, e.g. source code, compiled code, interpreted code, machine code
• CPC Class Codes: G06F 21/16 Program or content traceability, e.g. by watermarking
• CPC Class Codes: G06F 21/563 by source code analysis

Abstract

A system is disclosed for identifying and preventing non-compliant uses of any portion of source code or other protected content. The system includes at least one processor and a memory storing instructions that cause the system to scan files located at a source location for excerpts of protected source code. The instructions may cause the system to create a temporary clone detection structure for the files at the source location. The instructions may cause the system to use the temporary clone structure and a pre-calculated clone structure for source code files in a protected code location, to identify code clones, and to generate data used to alert a user that the source location includes portions of source code from the protected code location. When clones are found, the instructions may optionally cause the system to prevent the copying of the files containing the code clones.

Claims

1. A system comprising:

one or more processors; and

a memory storing instructions that, when executed by the one or more processors, perform operations comprising;

receiving a location for a first source code file,

determining that the received location is a restricted location,

creating, in response to the determining, a temporary index of normalized statements for the first source code file,

comparing the temporary index of normalized statements for the first source code file having the restricted location and a pre-calculated index of normalized statements for second source code files stored in a protected code location to identify a number of code clones in the first source code file,

determining whether the number of identified code clones in the first source code file meets a threshold, and

generating data used to alert a user that the restricted location contains code clones when it is determined that the number of identified code clones meets the threshold.

2. The system of claim 1, wherein the restricted location includes two or more source code files and the operation of determining whether the number of identified code clones meets the threshold includes:

for a specific source code file, determining whether a number of code clones for the specific file meets the threshold.

3. The system of claim 2, the operations further comprising:

preventing the specific source code file from being copied when it is determined that the number of code clones for the specific file meets the threshold.

4. The system of claim 1, wherein the threshold is based on a length of at least one of the number of code clones.

5. The system of claim 1, wherein the restricted location includes two or more source code files and the operation of determining whether the number of identified code clones meets the threshold includes:

for each of the two or more source code files, determining a number of code clones for each file;

calculating an average number of code clones per file; and

determining whether the average number of code clones meets the threshold.

6. The system of claim 1, wherein the restricted location is an attachment location for an e-mail message, and the first source code file is the attachment.

7. The system of claim 6, the operations further comprising:

preventing the first source code file from being sent with the e-mail message when it is determined that the number of identified code clones meets the threshold.

8. The system of claim 1, wherein the restricted location is a source location in a request to copy files from the source location to a destination location.

9. The system of claim 8, the operations further comprising:

preventing the copying of at least one of the source code files when it is determined that the number of identified code clones meets the threshold.

10. The system of claim 1, wherein the restricted location is a destination location in a request to copy files from a source location to the destination location and the operations further comprise:

preventing the copying of the first source code file to the destination location when it is determined that the number of identified code clones meets the threshold.

11. The system of claim 10, wherein the destination location is a directory associated with a remote data center.

12. The system of claim 10, wherein the destination location is a location for an attachment to be sent via e-mail.

13. The system of claim 1, wherein the restricted location is a directory on a mobile computing device.

14. The system of claim 13, wherein the data used to alert the user indicates that the mobile device contains portions of source code from the protected code location.

15. The system of claim 13, wherein the operation of receiving the location is performed in response to the mobile device connecting to a computing device with access to the protected code location.

16. A computer-readable storage device for detecting non-compliant use of portions of source code, the storage device having recorded and embodied thereon instructions that, when executed by one or more processors of a computer system, cause the computer system to:

receive a location of one more source code files;

determine that the location is a restricted location;

create, in response to the receiving, a temporary index of tokenized statements for each of the one or more source code files;

compare the temporary index for one or more source code files having the restricted location and a pre-calculated index of tokenized statements from source code files stored in a protected code location to identify a number of code clones in the one or more source code files;

determine whether the number of identified code clones meets a threshold; and

generate data used to alert a user that the restricted location contains code clones when it is determined that the number of identified code clones meets the threshold.

17. The storage device of claim 16, wherein as part of determining whether the number of identified code clones meets the threshold, the instructions further cause the computer system to, for a specific source code file having the restricted location:

determine a percentage of the specific source code file that contains code clones; and

determine whether the percentage meets the threshold.

18. The storage device of claim 16, wherein the restricted location is a source location from a request to copy the one or more source code files from the source location to the protected code location and the instructions further cause the computer system to:

prevent the one or more source code files from being added to the protected code location when it is determined that the number of identified code clones meets the threshold.

19. The storage device of claim 16, wherein the location is the location of a destination directory in a request to copy files from a source directory to the destination directory.

20. The storage device of claim 19, wherein the instructions further cause the computer system to:

prevent the copying of one or more portions of the at least one of the source code files when it is determined that the number of identified code clones meets the threshold.

21. The storage device of claim 16, wherein the restricted location is an attachment to an email and the instructions further cause the computer system to:

prevent the sending of the one or more source code files as the attachment to the email.

22. The storage device of claim 16, wherein a code clone includes a sequence of normalized statements from the temporary index that match a sequence of normalized statements from the pre-calculated index.

23. A computer-implemented method comprising:

receiving, by one or more processors, a request to copy portions of one or more source code files from a source location to a destination location;

identifying a number of code clones between the one or more source code files and source code from a protected code location;

determining whether the number of identified code clones meets a threshold;

determining whether the destination location is authorized to contain source code from the protected code location; and

preventing one or more portions of the source code files from being copied from the source location to the destination location when it is determined that the number of identified clones meets the threshold and that the destination location is not authorized to contain source code from the protected code location.

24. The method of claim 23, wherein the source location is associated with a first data center and the destination location is associated with a second data center.

25. The method of claim 24, wherein determining whether the destination location is authorized is based on a geographical location of the second data center.

26. The method of claim 23, wherein the destination location is associated with a portable, removable, storage device.