Obfuscation of automatically generated code

• US 8,832,646 B1
• Filed: 03/26/2010
• Issued: 09/09/2014
• Est. Priority Date: 01/18/2005
• Status: Active Grant

• Current Assignee: The MathWorks, Inc.
• Original Assignee: The MathWorks, Inc.
• Inventors: Wendling, Bill
• Primary Examiner(s): Deng, Anna
• Application Number:
  US12/732,551
• Time in Patent Office: 1,628 Days
• Field of Search: 717/105, 717/109, 717/110, 717/111, 717/113
• US Class Current: 717/113
• CPC Class Codes: G06F 21/1066 Hiding content
• CPC Class Codes: G06F 21/14 against software analysis or reverse engineering, e.g. by obfuscation
• CPC Class Codes: G06F 8/34 Graphical or visual programming

Abstract

A method is provided for obfuscating code generated from a block diagram model in a graphical programming environment. The obfuscation may be removed through the use of a password. Incorporating the obfuscated code in a block diagram allows for code to be generated from the block diagram incorporating the obfuscated code.

Claims

1. A computing device-implemented method comprising:

receiving a first graphical model;

generating, by a processor of the computing device, textual code for the first graphical model, the generating including;

generating a plurality of related files required for compiling the generated textual code;

converting the generated textual code for the first graphical model into obfuscated textual code, the converting including;

converting the plurality of related files to plurality of obfuscated related files;

receiving a second graphical model, where;

the second graphical model includes the first graphical model, and

the second graphical model is executable;

incorporating the obfuscated textual code into the second graphical model using a graphical element, where;

the incorporating associates the plurality of obfuscated related files with the second graphical model, and

the obfuscated textual code interacts with a portion of the second graphical model, the interacting comprising;

receiving output from the portion of the second graphical model, or

providing input to the portion of the second graphical model; and

generating code for the second graphical model, the generating comprising;

incorporating the obfuscated textual code into the generated code.

2. The computing device-implemented method of claim 1, wherein converting the generated textual code for the first graphical model into obfuscated textual code comprises:

selecting one or more obfuscation techniques based on functional criteria of the first graphical model and/or functional criteria of the generated textual code.

3. The computing device-implemented method of claim 2, wherein the one or more obfuscation techniques comprise at least one of:

altering or removing comments from the generated textual code.

4. The computing device-implemented method of claim 2, wherein the one or more obfuscation techniques comprises:

altering a representation of one or more strings in the generated textual code.

5. The computing device-implemented method of claim 2, wherein the one or more obfuscation techniques comprises:

applying a one-way hash function to the generated textual code.

6. A non-transitory computer-readable medium storing instructions that, when executed on a processor, cause the processor to:

receive a first graphical model;

generate textual code for the first graphical model, the generating including;

generating a plurality of related files required for compiling the generated textual code;

convert the generated textual code for the first graphical model into obfuscated textual code, the converting including;

converting the plurality of related files to plurality of obfuscated related files;

receive a second graphical model, where;

the second graphical model includes the first graphical model, and

the second graphical model is executable; and

incorporate the obfuscated textual code into the second graphical model using a graphical element, where;

the incorporating associates the plurality of obfuscated related files with the second graphical model, and

the obfuscated textual code interacts with a portion of the second graphical model, the interacting comprising;

receiving output from the portion of the second graphical model, or

providing input to the portion of the second graphical model; and

generate code for the second graphical model, the generating comprising;

incorporating the obfuscated textual code into the generated code.

7. The non-transitory computer-readable medium of claim 6, wherein instructions for converting the generated textual code for the first graphical model into obfuscated textual code comprise instructions for selecting one or more obfuscation techniques based on functional criteria of the graphical model and/or functional criteria of the generated textual code.

8. The non-transitory computer-readable medium of claim 7, wherein the one or more obfuscation techniques comprise at least one of:

altering comments or removing comments from the generated textual code.

9. The non-transitory computer-readable medium of claim 7, wherein the one or more obfuscation techniques comprise altering a representation of one or more strings in the generated textual code.

10. The non-transitory computer-readable medium of claim 7, wherein the one or more obfuscation techniques comprise applying a one-way hash function to the generated textual code.

11. The non-transitory computer-readable medium of claim 7, wherein the one or more obfuscation techniques comprise renaming non-system header files.

12. The non-transitory computer-readable medium of claim 7, wherein the one or more obfuscation techniques comprise replacing constants with obfuscated representations.

13. The non-transitory computer-readable medium of claim 6, further storing instructions that, when executed on the processor, cause the processor to:

compile the obfuscated textual code.

14. The non-transitory computer-readable medium of claim 13, further storing instructions that, when executed on the processor, cause the processor to:

obfuscate files necessary to compile the obfuscated textual code.

15. The non-transitory computer-readable medium of claim 6, wherein the obfuscation is deterministic.

16. The non-transitory computer-readable medium of claim 15, further storing instructions that, when executed on the processor, cause the processor to:

receive an indication from a user to break determinism of the obfuscation; and

wherein instructions for converting the generated textual code to obfuscated textual code comprise instructions for generating the obfuscated textual code in a non-deterministic manner.

17. The non-transitory computer-readable medium of claim 6, wherein instructions for converting the generated textual code into obfuscated textual code further comprise instructions for converting files containing functionality as well as non-system interface files used by the functionality files.

18. The non-transitory computer-readable medium of claim 17, wherein the functionality files are C files and the interface files are header files.

19. A computer-implemented system comprising:

a memory storing a first graphical model;

a processor executing instructions for generating textual code for the first graphical model, the generating including;

generating a plurality of related files required for compiling the generated textual code;

a converter for converting the generated textual code for the first graphical model into obfuscated textual code, the converting including;

converting the plurality of related files to plurality of obfuscated related files;

wherein the memory stores;

a second graphical model, where;

the second graphical model includes the first graphical model,

the obfuscated textual code is incorporated into the second graphical model using a graphical element,

the second graphical model is executable,

the incorporating associates the plurality of obfuscated related files with the second graphical model, and

the obfuscated textual code interacts with a portion of the second graphical model, the interacting comprising;

receiving output from the portion of the second graphical model, or

providing input to the portion of the second graphical model; and

code generated from the second graphical model, the code generated from the second graphical model including the obfuscated textual code.

20. A non-transitory computer readable medium storing instructions that, when executed on a processor, cause the processor to:

receive a first graphical model;

generate textual code for at least a portion of the first graphical model, the generating including;

generating a plurality of related files required for compiling the generated textual code;

convert the generated textual code for at least the portion of the first graphical model into obfuscated textual code, where the converting includes;

converting the plurality of related files to plurality of obfuscated related files, and

applying a one-way hash function to the generated textual code;

incorporate the generated obfuscated textual code into a second graphical model using a graphical element, where;

the second graphical model is executable,

the incorporating associates the plurality of obfuscated related files with the second graphical model, and

the obfuscated textual code interacts with a portion of the second graphical model, the interacting comprising;

receiving output from the portion of the second graphical model, or

providing input to the portion of the second graphical model; and

generate code for the second graphical model, the generating comprising;

incorporating the obfuscated textual code into the generated code.

21. The non-transitory computer-readable medium of claim 20, wherein the second graphical model is the same as the first graphical model.

22. The non-transitory computer-readable medium of claim 20, wherein instructions for converting the generated textual code into obfuscated textual code further comprise instructions for:

structurally manipulating textual code while preserving functionality of the textual code.

23. The non-transitory computer-readable medium of claim 22, wherein instructions for structurally manipulating textual code further comprise instructions for at least one or a combination of:

replacing constants with obfuscated representations;

altering or removing comments from the generated textual code;

altering a representation of one or more strings in the generated textual code; and

changing location of sections of the generated textual code relative to each other.

24. A computing device-implemented method comprising:

receiving a first graphical model;

generating, by a processor of the computing device, textual code for at least a portion of the first graphical model, the generating including;

generating a plurality of related files required for compiling the generated textual code;

converting the generated textual code for at least the portion of the first graphical model into obfuscated textual code, where the converting includes;

converting the plurality of related files to plurality of obfuscated related files, and

applying a one-way hash function to the generated textual code; and

incorporating the generated obfuscated textual code into a second graphical model via a graphical element, where;

the second graphical model is executable,

the incorporating associates the plurality of obfuscated related files with the second graphical model, and

the obfuscated textual code interacts with a portion of the second graphical model, the interacting comprising;

receiving output from the portion of the second graphical model, or

providing input to the portion of the second graphical model; and

generating code for the second graphical model, the generating comprising;

incorporating the obfuscated textual code into the generated code.