Browse Prior Art Database

Security Limited Program for Modifying Programs Stored on Disks

IP.com Disclosure Number: IPCOM000074733D
Original Publication Date: 1971-Jun-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 3 page(s) / 68K

Publishing Venue

IBM

Related People

Housel, BC: AUTHOR [+2]

Abstract

The subject modification program module may be used to display and modify program modules stored on disks. The program has the ability to retrieve each instruction (record) in a program stored on disk. The retrieved record is displayed and the operator may modify the record by keying in on his console a new record. The modification program routine is security-limited in that to use the program, the user must have an identification indicating that he is authorized to use the program. User identification list is preassembled into the modification program. The modification program asks each user for his identification. If the user's identification is not on the list, the user will not be permitted to use the modification program.

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Security Limited Program for Modifying Programs Stored on Disks

The subject modification program module may be used to display and modify program modules stored on disks. The program has the ability to retrieve each instruction (record) in a program stored on disk. The retrieved record is displayed and the operator may modify the record by keying in on his console a new record. The modification program routine is security-limited in that to use the program, the user must have an identification indicating that he is authorized to use the program. User identification list is preassembled into the modification program. The modification program asks each user for his identification. If the user's identification is not on the list, the user will not be permitted to use the modification program.

As further security, the modification program is inhibited from displaying any record or instruction contained in the modification program itself. This prevents an authorized user from violating the security of the modification program. One violation without this inhibiting limitation might be where an authorized user queries the program itself to determine who the other authorized users are. The program is best understood by proceeding through the flow chart shown.

Operation is initiated by a supervisor program turning over control to the modification program module herein identified as MODISK -- an acronym for MODIFY DISK STORED PROGRAMS. The first step 10 of the program is to display the operating instructions to the console operator. The first request to the operator occurs at step 12. The operator is queried as to his user identification. The operator then keys in his identification at the console. If he is an authorized user, decision block 14 passes program control onto block 16. However, if the user is not authorized, the language "job cancelled" is displayed to the user and program control returns to the supervisory program.

Step 16 is a query as to what program module is to be modified. The operator keys in the program name of the module to be modified. If the name is MODISK - - the operator wishes to operate on the program module which controls modifications -- a SET MODISK flag step 18 occurs. The MODISK flag is used later as a part of the security limitation. If the program module being modified is not MODISK, program control passes directly on to finding the requested program on disk.

At step 20, the program gets the record address of the record to be modified. This record address is the core location of the record if the program stored on disk were loaded into core. If the record address satisfies the END OF JOB address, decision block 22 passes control back to the supervisor. If the record address is not indicative of end of job, program control passes to decision block
24.

Decision block 24 asks the user if he is going to modify the record. If the user's response is yes, the program sets a modify flag and program control returns...