Safe I/O through use of opaque I/O objects

• US 20030167350A1
• Filed: 06/04/2002
• Published: 09/04/2003
• Est. Priority Date: 06/07/2001
• Status: Abandoned Application

• Current Assignee: Sumisho Computer Systems Corporation (Sumitomo Corporation)
• Original Assignee: Curl Corp.
• Inventors: Davis, Donald T., Kranz, David A.
• Application Number:
  US10/163,095
• Publication Number:
  US 20030167350A1
• Time in Patent Office: Days
• US Class Current: 719/316
• CPC Class Codes: G06F 21/52 during program execution, e.g. stack integrity ; Preventing unwanted data erasure; Buffer overflow
• CPC Class Codes: G06F 21/53 by executing in a restricted environment, e.g. sandbox or secure virtual machine
• CPC Class Codes: G06F 9/468 Specific access rights for resources, e.g. using capability register

Abstract

Opaque I/O objects are described which can be used in a variety of mobile code systems to permit unprivileged applets to perform a wide variety of I/O operations in a safe manner. Such opaque objects permit limited I/O without requiring the user of an applet to confer trust or privilege on the applet, and without exposing the user to a risk of his data being destroyed, compromised, or stolen by malicious applets.

Claims

1. A method for safely permitting limited operations by untrusted or unprivileged applets in an object-oriented computer system, comprising:

defining objects that provide for classifying data and methods performing input operations or output operations on the data to limit access to the input operations, the output operations or the data; and

using the objects to control access to the input operations, the output operations or the data.

2. The method of claim 1 wherein the object-oriented computer system is a mobile code computer system.

3. The method of claim 1 wherein the control comprises restricting access to at least one of the input operations, the output operations and the data.

4. The method of claim 1 wherein the control comprises notifying a user prior to accessing to at least one of the input operations, the output operations and the data.

5. The method of claim 1 wherein the control comprises receiving authorization from a user prior to accessing to at least one of the input operations, the output operations and the data.

6. The method of claim 1 wherein the input operations are classified as sensitive or non-sensitive.

7. The method of claim 1 wherein the input operations are classified as loud or silent.

8. The method of claim 1 wherein the output operations are classified as low- risk or high-risk.

9. The method of claim 1 wherein the output operations are classified as immediate or delayed.

10. The method of claim 1 wherein the data is classified as accessible or locked.

11. The method of claim 1 further comprising using the objects to control access to the input operations or the output operations and the data through events.

12. The method of claim 11 wherein the events are classified as authentic or synthetic.