Static program analysis of a partial software program

• US 10,558,550 B2
• Filed: 11/10/2017
• Issued: 02/11/2020
• Est. Priority Date: 11/10/2017
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Malton, Andrew James, Walenstein, Andrew
• Primary Examiner(s): Zhen, Wei Y
• Assistant Examiner(s): Bourzik, Brahim
• Application Number:
  US15/809,676
• Publication Number:
  US 20190146897A1
• Time in Patent Office: 823 Days
• Field of Search: 717124
• CPC Class Codes: G06F 11/3604 Software analysis for verifying properties of programs byte-code verification G06F9/44589
• CPC Class Codes: G06F 11/3608 using formal methods, e.g. model checking, abstract interpretation theorem proving G06N5/013
• CPC Class Codes: G06F 21/577 Assessing vulnerabilities and evaluating computer system security
• CPC Class Codes: G06F 2221/033 Test or assess software

Abstract

A method for analyzing a partial software program includes receiving a first software program. The first software program is designed to execute using a second software program. A first symbolic value indicates a characteristic of the second software program. The first software program is analyzed using a static program analysis, where the static program analysis generates a second symbolic value based on the first symbolic value. The second symbolic value indicates a characteristic of the first software program. The first software program is analyzed independent of an availability of the second software program. In response to determining that the second symbolic value is associated with a predetermined characteristic and that the first software program would perform an action associated with the second symbolic value if the first software program was executed using the second software program, a warning signal is generated.

Claims

1. A method, comprising:

receiving, by a hardware processor, a first software program, wherein the first software program is designed to execute using a second software program, wherein the first software program comprises a first symbolic value indicating a characteristic of the second software program, the first symbolic value indicating a parameter that the first software program requests from the second software program;

Analyzing, by the hardware processor, the first software program using a static program analysis, wherein the analyzing the first software program using the static program analysis comprises;

Determining whether a concrete value exists for the parameter that the first software program requests from the second software program; and

in response to determining that no concrete value exists for the parameter that the first software program requests from the second software program, generating a second symbolic value based on the first symbolic value, the second symbolic value indicating a characteristic of the first software program, wherein the first software program is analyzed independent of an availability of the second software program;

wherein the static program analysis generates a plurality of threads, each of the plurality of thread corresponding to a conditional branch of the first software program, wherein the plurality of threads are executed separately by the static program analysis;

determining, by the hardware processor, that the second symbolic value is associated with a predetermined characteristic indicating private data associated with a security policy and determining that an action associated with the second symbolic value resulting from executing the first software program using the second software program would be a violation of the security policy, wherein the action is exporting the second symbolic value from the first software program to an unauthorized entity;

In response to the determining, generating, by the hardware processor, a warning signal; and

sending the warning signal to a user interface.

2. The method of claim 1, wherein the first software program is in a machine language format.

3. The method of claim 1, wherein the first software program comprises an application, and the second software program comprises at least a portion of an operating system.

4. The method of claim 1, wherein the first software program is associated with a register, and the second symbolic value is stored in the register.

5. The method of claim 1, wherein the action is exporting the second symbolic value in the register to an entity different than the first software program.

6. The method of claim 1, wherein analyzing the first software program comprises updating the second symbolic value, and the method further comprises continuing a thread until the updating stops.

7. The method of claim 1, wherein the static program analysis includes a symbolic computation and a concrete computation.

8. The method of claim 1, wherein the predetermined characteristic is a security characteristic.

9. A device, comprising:

A memory; and

At least one hardware processor communicatively coupled with the memory and configured to;

receive a first software program, wherein the first software program is designed to execute using a second software program, wherein the first software program comprises a first symbolic value indicating a characteristic of the second software program, the first symbolic value indicating a parameter that the first software program requests from the second software program;

Analyze the first software program using a static program analysis, wherein the analyzing the first software program using the static program analysis comprises;

Determining whether a concrete value exists for the parameter that the first software program requests from the second software program; and

in response to determining that no concrete value exists for the parameter that the first software program requests from the second software program, generating a second symbolic value based on the first symbolic value, the second symbolic value indicating a characteristic of the first software program, wherein the first software program is analyzed independent of an availability of the second software program;

wherein the static program analysis generates a plurality of threads, each of the plurality of thread corresponding to a conditional branch of the first software program, wherein the plurality of threads are executed separately by the static program analysis;

determine that the second symbolic value is associated with a predetermined characteristic indicating private data associated with a security policy and determining that an action associated with the second symbolic value resulting from executing the first software program using the second software program would be a violation of the security policy, wherein the action is exporting the second symbolic value from the first software program to an unauthorized entity;

in response to the determining, generate a warning signal;

send the warning signal to a user interface.

10. The device of claim 9, wherein the first software program comprises an application, and the second software program comprises at least a portion of an operating system.

11. The device of claim 9, wherein the first software program is associated with a register, and the second symbolic value is stored in the register.

12. The device of claim 11, wherein the action is exporting the second symbolic value in the register to an entity different from the first software program.

13. The device of claim 9, wherein analyzing the first software program comprises updating the second symbolic value, and wherein analyzing the first software program further comprises continuing a thread until the updating stops.

14. The device of claim 9, wherein the static program analysis includes a symbolic computation and a concrete computation.

15. The device of claim 9, wherein the predetermined characteristic is a security characteristic.

16. A non-transitory computer-readable medium containing instructions which, when executed, cause a computing device to perform operations comprising:

receiving a first software program, wherein the first software program is designed to execute using a second software program, wherein the first software program comprises a first symbolic value indicating a characteristic of the second software program, the first symbolic value indicating a parameter that the first software program requests from the second software program;

Analyzing the first software program using a static program analysis, wherein the analyzing the first software program using the static program analysis comprises;

determining whether a concrete value exists for the parameter that the first software program requests from the second software program; and

in response to determining that no concrete value exists for the parameter that the first software program requests from the second software program, generating a second symbolic value based on the first symbolic value, the second symbolic value indicating a characteristic of the first software program, wherein the first software program is analyzed independent of an availability of the second software program;

wherein the static program analysis generates a plurality of threads, each of the plurality of thread corresponding to a conditional branch of the first software program, wherein the plurality of threads are executed separately by the static program analysis;

determining that the second symbolic value is associated with a predetermined characteristic indicating private data associated with a security policy and determining that an action associated with the second symbolic value resulting from executing the first software program using the second software program would be a violation of the security policy, wherein the action is exporting the second symbolic value from the first software program to an unauthorized entity;

in response to the determining, generating a warning signal; and

sending the warning signal to a user interface.

17. The non-transitory computer-readable medium of claim 16, wherein the first software program comprises an application, and the second software program comprises at least a portion of an operating system.

18. The non-transitory computer-readable medium of claim 16, wherein the static program analysis includes a symbolic computation and a concrete computation.