Software security system for maintaining integrity of compiled object code by restricting users ability to define compilers

• US 5,111,390 A
• Filed: 08/22/1988
• Issued: 05/05/1992
• Est. Priority Date: 08/22/1988
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Unisys Corporation
• Inventors: Ketcham, Larry R.
• Primary Examiner(s): Williams, Jr., Archie E.
• Assistant Examiner(s): Coleman, Eric
• Application Number:
  US07/234,772
• Time in Patent Office: 1,352 Days
• Field of Search: 364/200 MS File, 364/900 MS File, 364/300, 380/3, 380/4, 380/25, 380/26
• US Class Current: 717/170
• CPC Class Codes: G06F 21/57 Certifying or maintaining trusted computer platforms, e.g. secure boots or power-downs, version controls, system software checks, secure updates or assessing vulnerabilities

Abstract

A computer system which uses a main processor with main memory, and operates under a specialized software operating system, provides for checking the integrity of its compiler by use of software routines which permit an authorized user or an authorized program to authorize a file as a compiler and additionally will operate to identify any ordinary user and ordinary programs so as to prevent such ordinary user or ordinary program from authorizing a code file as a compiler.

Claims

1. In a computer system having program files, the method of authorizing a code file as a compiler, comprising the steps of:

(a) establishing, via an operating system, a FILEKIND attribute value to differentiate files as to being a data file, a code file, or an authorized compiler;

(b) requesting, via a first program, the operating system to assign a FILEKIND value to a secondprogram, where said first program is prevented, by the operating system, from assigning a FILEKIND value that would indicate a code file or a compiler;

(c) establishing, via an operating system routine, the ability to assign a COMPILERCODEFILE value to a program'"'"'s FILEKIND attribute where only a privileged user/privileged program is permitted access to the operating system routine, designated SETSTATUS, wherein said COMPUTERCODE FILE value represents an integer created by the operating system which designates a code file as a compiler;

(d) permitting, via a supervisory program designated DCKEYIN, that only a privileged user or privileged program, will get access capability to request, via said operating system routine, said operating system to authorize a code file as a compiler.

2. The method of claim 1 which includes the step of:

(6e) preventing, via said operating system, any ordinary user or ordinary program from changing the FILEKIND attribute value of a code file into a COMPILERCODEFILE value.

3. The method of claim 1 which includes the step of:

(7e) operating a program that invokes a Master Control Program (MCP) as the said operating system via the SETSTATUS entry point which will authorize a code file as a compiler by changing the FILEKIND value into a COMPILERCODEFILE value.

4. In a computer system, the method of controlling files which might be used as a compiler, comprising the steps of:

(a) providing, through a system administrator, a Master Control Program (MCP) which includes an entry point designated SETSTATUS which has the capability of changing a FILEKIND attribute value of a designated file into a COMPILERCODEFILE value;

(b) establishing a routine, designated as DCKEYIN, for receiving a MAKE COMPILER command from both ordinary programs and privileged programs;

(c) denying, through said DCKEYIN routine, said ordinary programs from transmitting said MAKE COMPILER command to a CONTROLLER program, where said CONTROLLER program initiates entry into said SETSTATUS program entry point of said Master Control Program;

(d) permitting, via said DCKEYIN routine, said privileged program to transmit said MAKE COMPILER command to said CONTROLLER program;

(e) receiving, by said CONTROLLER program, of said MAKE COMPILER command from said DCKEYIN routine;

(f) transmitting, by said CONTROLLER program, of said MAKE COMPILER command to said SETSTATUS entry point of said MCP operating system;

(g) changing, via said SETSTATUS initiation of said MCP operating system, the FILEKIND value of said designated file into the COMPILERCODEFILE value which will authorize said designated file to operate as a compiler.

5. In a computer system, the method of controlling files which might be used as a compiler, comprising the steps of:

(a) establishing, by a system administrator, a Master Control Program (MCP) which includes an entry point designated SETSTATUS having the capability of changing a FILEKIND attribute value of a designated file into a COMPILERCODEFILE value;

(b) providing, via said system administrator, a CONTROLLER program to transmit MAKE COMPILER commands to said SETSTATUS entry point, and to receive MAKE COMPILER commands from a menu-assisted resource control (MARC) program;

(c) inputting, from ordinary users and privileged users, the MAKE COMPILER commands into said MARC program;

(d) inhibiting, by said MARC program, said MAKE COMPILER commands from said ordinary users;

(e) transmitting, by said MARC program, said MAKE COMPILER commands from privileged users to said CONTROLLER program;

(f) initiating, via said CONTROLLER program, of the SETSTATUS entry point of the Master Control Program to authorize the program designated by the MAKE COMPILER command.

6. The method of claim 5 which includes the step of:

(10g) generating, by said CONTROLLER program, the transmission of a MAKE COMPILER command, when originated from a privileged operator terminal, to said CONTROLLER program for input to said SETSTATUS entry point to achieve authorization of a code file as a compiler.

7. A method for ensuring that only properly privileged personnel and programs can authorize a code file as a compiler in a computer system, said method comprising the steps of:

(a) providing, via a system administrator, a Master Control Program (MCP) operating system which includes safeguard routines to check any "MAKE COMPILER" command generated in said system, said MCP being initiated via a SETSTATUS entry point;

(b) recognizing, by checking the FILEKIND attribute, via the said MCP operating system, whether a file is or is not a compiler;

(c) assigning, via a program, a FILEKIND value to a file which will identify it as a "compiler" or as a "code file" or as a "system code file" or as a "data file";

(d) checking out the source of any "MAKE COMPILER" commands by means of programs designated as DCKEYIN, and menu-assisted resource control (MARC) which cooperate with a CONTROLLER program which can allow or deny further transmission of the MAKE COMPILER command to the SETSTATUS entry point of the MCP operating system;

(e) enabling, via the said SETSTATUS entry point and the MCP operating system, the MAKE COMPILER command to authorize a file to act as a compiler.