Computer system security method and apparatus for creating and using program authorization information data structures

• US 5,311,591 A
• Filed: 06/03/1993
• Issued: 05/10/1994
• Est. Priority Date: 05/15/1992
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: Addison M. Fischer
• Inventors: Fischer, Addison M.
• Primary Examiner(s): Cain, David C.
• Application Number:
  US08/070,787
• Time in Patent Office: 341 Days
• Field of Search: 380/4
• US Class Current: 713/156
• CPC Class Codes: G06F 12/1483 using an access-table, e.g. matrix or list
• CPC Class Codes: G06F 21/54 by adding security routines or objects to programs
• CPC Class Codes: G06F 2211/007 Encryption, En-/decode, En-/decipher, En-/decypher, Scramble, (De-)compress

Abstract

Method and apparatus are disclosed including a system monitor which limits the ability of a program about to be executed to the use of predefined resources (e.g., data files, disk writing capabilities, etc.). The system monitor processes a data structure including a set of authorities defining that which a program is permitted to do and/or that which the program is precluded from doing. The set of authorities and/or restrictions assigned to a program to be executed are referred to as "program authorization information" (or "PAI"). Once defined, the program authorization information is thereafter associated with at least one program to be executed to thereby delineate the resources and functions that the program is allowed to utilize and/or is not allowed to utilize. The PAI associated with a particular program may be assigned by a computer system owner/user or by someone who the computer system owner/user implicitly trusts. The PAI permits an associated program to access what has been authorized and nothing else. The program may be regarded as being placed in a program capability limiting "safety box". This "safety box" is thereafter associated with the program such that when the system monitor runs the program, the PAI for that program is likewise loaded and monitored. When the program is to perform a function or access a resource, the associated PAI is monitored to confirm that the operation is within the defined program limits. If the program is prevented from doing anything outside the authorized limits.

Claims

1. In a computer system including processing means for executing a plurality of programs and memory means coupled to said processing means for storing data and for storing at least one program, said computer system having a plurality of computer resources and being capable of performing a wide range of information processing related functions under program control, a method for protecting a computer user from operations typically performable by a program while it is executing on behalf of a user, comprising the steps of:

establishing a program authorizing information data structure for storing a plurality of authorization entries each indicating at least one of those computer resources and information processing related functions which may be used by an associated program;

storing said program authorizing information data structure; and

associating the program authorizing information data structure with at least one program to be executed by said computer system to thereby protect the computer user from operations that might be performed by said at least one program, whereby the program authorizing information is available to be monitored when its associated program is executed.

2. A method according to claim 1, further including the step of including a digital hash of said program to be executed as part of the program authorization information data structure.

3. A method according to claim 1, further including the step of digitally signing at least a part of the program authorization information data structure with the private key of an authorizing entity.

4. A method according to claim 3, wherein the digitally signing step includes indicating that a plurality of digital signatures are required in order for any digital signature to be valid.

5. A method according to claim 3, wherein the digitally signing step includes the step of indicating at least one qualification of authority which has been granted to the signer.

6. A method according to claim 1, wherein the program authorization information data structure is defined by a computer user before an associated program is executed.

7. A method according to claim 1, wherein the step of establishing provides an indication of at least a part of at least one data file to which the program may have access.

8. A method according to claim 7, wherein the indication of at least one data file includes an indication of the file by designating a portion of the file name.

9. A method according to claim 8, wherein said indication of the file by designating a portion of the file name, operates to define a set of files.

10. A method according to claim 1, wherein the step of establishing provides an indication of at least a subset of at least one file to which a program to be executed has access.

11. A method according to claim 1, wherein the step of establishing associates a set of files to which a program to be executed has access.

12. A method according to claim 1, wherein the step of establishing provides an indication of at least a subset of at least one file to which the program does not have access.

13. A method according to claim 1, wherein the step of establishing associates at least one file to which a program to be executed has access and indicates the ability to read information from said file.

14. A method according to claim 1, wherein the step of establishing associates at least part of one file to which a program to be executed has access and indicates the limitations in the ability to use said part.

15. A method according to claim 1, wherein the step of establishing provides an indication of at least one file to which a program to be executed has access and specifies the ability to write information in said at least one file.

16. A method according to claim 1, wherein the step of establishing provides an indication of the set of programs which are authorized to be invoked by said program.

17. A method according to claim 1, wherein the step of establishing associates the ability to invoke other programs which may have different authorizing information than the associated program with said associated program.

18. A method according to claim 1, wherein the step of establishing provides as indication of denying said associated program the ability to invoke other programs having different program authorizing information.

19. A method according to claim 1, wherein the establishing step provides an indication of the ability to invoke other programs restricted only by the limits of the calling program.

20. A method in accordance with claim 16, wherein the associated program authorizing information limits the effective program authorization of an invoked program by the combination of its own program authorizing information and that of the calling program.

21. A method according to claim 1, wherein the step of establishing associates an indication of the set of programs which are authorized to invoke said program.

22. A method according to claim 1, further including the step of limiting, using said stored program authorizing information associated with a program to be executed, the use of at least one of the resources and functions which would otherwise be available to said program.

23. A method according to claim 22, wherein the step of limiting includes limiting the resources and functions which are available to other programs which are invoked by the program which is being executed.

24. A method according to claim 1, wherein the step of establishing provides an indication of at least one rule governing the authority of said associated program to transmit information.

25. A method according to claim 24, wherein said at least one rule provides an indication of the authority to transmit information and the step of establishing includes the step of defining the ability to utilize electronic mail.

26. A method according to claim 24, wherein said at least one rule provides an indication of the authority to transmit information and the step of establishing includes the step of indicating a subset of all possible recipients.

27. A method according to claim 1, wherein the step of establishing provides at least one rule governing the program'"'"'s ability to solicit digital signatures on behalf of the user.

28. A method according to claim 1, wherein the step of establishing provides at least one rule governing the program'"'"'s ability to create digital signatures.

29. A method according to claim 28, wherein said at least one rule governs the ability to solicit digital signatures by defining the type of material to which the digital signature can be applied.

30. A method according to claim 28, wherein said at least one rule limits the information which may digitally signed to those involving a predetermined maximum amount of money value.

31. A method according to claim 1, wherein the step of establishing qualifies the ability of other programs to perform document release operations on behalf of the user.

32. A method according to claim 1, wherein at least one rule qualifies program operation to a subset of possible security classifications.

33. A method according to claim 1, wherein the step of establishing provides a qualification of the ability of said associated program to execute machine language instructions.

34. A method according to claim 1, wherein the step of establishing qualifies the set of memory which the said associated program is permitted to access.

35. A method according to claim 34, wherein the permission to access includes the ability to alter.

36. A method according to claim 34, further including indicating that a particular class of memory is alterable.

37. A method according to claim 1, wherein the step of establishing provides an indication of the set of qualifications governing the ability of a program to display information to the user.

38. A method according to claim 1, wherein the step of establishing provides an indication of the set of qualifications governing the ability of the program to solicit information from a user.

39. A method according to claim 1, wherein the step of establishing provides an indication of the set of qualifications governing the ability of a program to control computer controlled resources which are coupled to the computer.

40. A method according to claim 39, wherein said computer controlled resources includes robot apparatus.

41. A method according to claim 39, wherein the set of qualifications governs the ability of the program to transmit information via a modem.

42. In a computer system having means for executing a plurality of programs and a memory means coupled to said means for executing, for storing data and program instructions, said computer system being capable of performing a wide range of information processing related operations under program control, a method for executing programs by said means for executing for a computer user comprising the steps of:

identifying a program to be executed;

determining whether a program authorizing information data structure has been associated with the program, wherein said program authorizing information qualifies the ability of the program from performing information processing related operations which are available to said computer user;

examining said program authorizing information data structure if one has been associated with said program;

determining from an examination of said program authorization information whether the associated program is allowed to perform an attempted information processing related operation; and

suppressing performance of said operation if said program authorizing information data structure indicates that said program is not allowed to perform an attempted operation.

43. A method according to claim 42, further including the step of checking said authorization information prior to permitting said program to utilize a required computer system resource.

44. A method according to claim 42, further including the step of checking whether said program authorization information data structure allows the performance of an operation defined in said associated program.

45. A method according to claim 42, further including the step of checking to determine whether a user has been assigned the authority to run programs performing a predetermined operation.

46. A method according to claim 42, further including the step of creating a program control data structure for said program and storing authorizing information related indicia in said program control data structure.

47. A method according to claim 46, wherein said authorizing information related indicia is a pointer to said authorizing information.

48. A method according to claim 42, further including the step of assigning a default program authorization information if said determining step reveals that no valid authorizing information has been associated with said program.

49. A method according to claim 42, further including the step of verifying any digital signature associated with said program authorization information data structure.

50. A method according to claim 49, including the step of suppressing the execution of said program if said digital signature is not valid.

51. A method according to claim 49, further including the step of allocating storage for said program if said digital signature is valid.

52. A method according to claim 42, further including the step of combining the authorizing information of said program with the authorizing information associated with a routine calling said program.

53. A method according to claim 42, wherein said authorizing information data structure includes means for storing a hash of said program, and further including the step of computing the hash of said program and comparing the computed hash with said stored hash.

54. A method according to claim 42, further including the step of verifying the authority associated with the signer of a digital signature.

55. A method according to claim 42, further including the step of combining the authorizing information of said program with the authorizing information associated with a routine called by said program.

56. A method according to claim 42, wherein said authorization information includes an indication of the set of data to which said associated program has authority to access.

57. A method according to claim 42, wherein said authorization information includes an indication of the set of fields of at least one file to which said associated program has the authority to access.

58. A method according to claim 42, wherein said authorization information includes an indication of the set of data to which said associated program has the authority to access and the nature of the operations on said data which the program is permitted to perform.

59. A method according to claim 42, wherein said authorization information includes an indication of the set of data to which said associated program has authority to read.

60. A method according to claim 42, wherein said authorization information includes an indication of the set of data to which said associated program has authority to process.

61. A method according to claim 42, wherein said authorization information includes an indication of the set of data to which said associated program has authority to modify.

62. A method according to claim 42, wherein said authorization information includes an indication of the set of data to which said associated program has authority to erase.

63. A method according to claim 42, wherein said authorization information includes an indication of the set of data to which said associated program has authority to transmit.

64. A method according to claim 42, wherein said authorization information includes an indication of whether said associated program has the ability to call programs.

65. A method according to claim 42, wherein said authorization information includes an indication of the set of programs which are allowed to invoke said associated program.

66. A method according to claim 42, wherein said authorization information includes an indication of at least one rule governing the authority of the associated program to generate electronic mail.

67. A method according to claim 42, wherein said authorization information includes an indication of at least one rule governing the authority of said said associated program to transmit data to other users.

68. A method according to claim 42, wherein said authorization information includes an indication of the ability of the associated program to perform document release.

69. A method according to claim 42, wherein said authorization information includes an indication of at least one rule governing the authority of said associated program to execute machine language programs.

70. A method according to claim 42, wherein said authorization information includes an indication of at least one rule governing the authority of said associated program to access memory.

71. A method according to claim 42, wherein said authorization information includes as indication of at least one rule governing the authority of said associated program to display information to a user.

72. A method according to claim 42, wherein said authorization information includes an indication of at least one rule governing the authority of said associated program to solicit input from a user.

73. A method according to claim 42, wherein said authorization information includes an indication of at least one rule governing the authority of said associated program to create digital signatures.

74. A method according to claim 42, wherein said authorization information includes an indication of at least one rule governing the authority of said associated program to control other devices.

75. A method according to claim 74, wherein said other devices includes robot devices.

76. A method according to claim 42, wherein said authorization information includes an indication of at least one rule indicating that access is governed by a security clearance.

77. A method according to claim 42, wherein said authorization information is included as part of a digital signature.