//DPFTCCUT JOB (9999,CC7),'CUT/EXTEND HISTORY',
//            CLASS=A,MSGCLASS=X
//*********************************************************************
//*                                                                   *
//* THIS UTILITY SOLVES THE "ORPHANED PASSWORD" PROBLEM IN RACF. THIS *
//* PROBLEM STEMS FROM THE FACT THAT WHEN REDUCING SETROPTS PASSWORD( *
//* HISTORY(..)) USERS MAY BE LEFT WITH OVERSIZE HISTORIES OF OLD     *
//* PASSWORDS, AND A FEW PASSWORDS WILL STAY IN THE HISTORY FOR EVER  *
//* AND CAN NEVER BE REUSED.                                          *
//*                                                                   *
//* CUTPWHIS TRUNCATES THE OLD PASSWORD HISTORY OF SUCH USERS.        *
//*                                                                   *
//* CUTPWHIS MAY ALSO BE USED TO ARTIFICIALLY EXTEND PASSWORD         *
//* HISTORIES WITH ENCRYPTED PASSWORDS THAT ARE BINARY ZEROES.        *
//* THIS MAY E.G. BE USEFUL WHEN MIGRATING TO RACF, AND A LARGE       *
//* SETROPTS PASSWORD(HISTORY(..)) VALUE WILL CAUSE USERIDS TO        *
//* EXTEND OVER MULTIPLE 256 BYTE CHUNKS AFTER SOME PASSWORD          *
//* INTERVAL PERIODS HAVE GONE. SUDDENLY ALMOST ALL USERIDS WILL      *
//* EXPAND INTO MULTIPLE CHUNKS, AND THAT IS BAD FOR PERFORMANCE.     *
//* IT IS BETTER TO EXTEND ALL USERS HISTORY WITH DUMMY ENTRIES       *
//* FROM THE BEGINNING.                                               *
//*                                                                   *
//* CUTPWHIS DOES NOT ALLOW MODIFYING HISTORIES TO A LENGTH ABOVE     *
//* CURRENT SETROPTS PASSWORD(HISTORY(..)) VALUE.                     *
//*                                                                   *
//* DDNAME USERIDS MAY BE USED TO LIMIT CUTPWHIS TO SELECTED USERIDS. *
//* EACH USERID MUST APPEAR AS FIRST 8 BYTES OF A RECORD.             *
//*                                                                   *
//*********************************************************************
//*                                                                   *
//* TO RUN THIS UTILITY, YOU MUST HAVE UPDATE ACCESS TO ENTITY        *
//* RACF.PASSWORD.MAINTENANCE.HISTORY.LNGTH IN CLASS FACILITY.        *
//*                                                                   *
//* THE UTILITY MUST RESIDE IN AN APF AUTHORIZED LIBRARY.             *
//*                                                                   *
//*********************************************************************
//*                                                                   *
//* SET PARM FIELD TO NO OF OLD PASSWORDS TO BE KEPT.                 *
//*                                                                   *
//* THE VALUE TO BE SPECIFIED IN PARM FIELD IS THE SAME AS USED IN    *
//* SETROPTS PASSWORD(HISTORY(..)).                                   *
//*                                                                   *
//* WHEN NO VALUE IS SET VIA THE PARM FIELD, CUTPWHIS TAKES IT DEFAULT*
//* FROM THE SETROPTS VALUES IN FORCE AT THE TIME OF EXECUTION.       *
//*                                                                   *
//*********************************************************************
//*EXAMPLE:  PASSWORD HISTORY VALUE IS 5.  NEW USER STARTS CHANGING   *
//*PASSWORDS USING A, B, C, ...                                       *
//*                                                                   *
//*    CURRENT PW    NEW GENERATION  HISTORY ELEMENTS                 *
//*                    (PWDGEN)OLDPWDNM/OLDPWD                        *
//*    -----------   --------------  -----------------                *
//*     INITIAL          255 OR 0    EMPTY                            *
//*       A                1         0/INITIAL                        *
//*       B                2         0/INITIAL, 1/A                   *
//*       C                3         0/INITIAL, 1/A, 2/B              *
//*       D                4         0/INITIAL, 1/A, 2/B, 3/C         *
//*       E                0         0/INITIAL, 1/A, 2/B, 3/C, 4/D    *
//*       F                1         1/A, 2/B, 3/C, 4/D, 0/E          *
//*       G                2         2/B, 3/C, 4/D, 0/E, 1/F          *
//*                                                                   *
//*PASSWORD HISTORY IS DECREASED TO 3.  THE PASSWORDS YOU NEED TO KEEP*
//*ARE THE LAST 3 IN THE LIST (D, E, F), AS THEY ARE THE MOST RECENT  *
//*3.                                                                 *
//*                                                                   *
//*HOWEVER, THEY NEED TO BE RENUMBERED. IF THE CHANGE HAPPENS AFTER   *
//*ROW G, AND YOU KEEP D, E, AND F, THEY CLEARLY CAN'T BE 4, 0, AND 1 *
//*AS NUMBERS ABOVE 2 ARE NOT LOGICAL. YOU COULD RENUMBER THEM        *
//*2, 0, 1, GIVING 2/D, 0/E, 1/F AND LEAVE PWDGEN UNCHANGED.          *
//*                                                                   *
//*BUT IT'S PROBABLY EASIER TO SET PWDGEN TO 0, AND RENUMBER THEM AS  *
//*0/E, 1/E, AND 2/F.                                                 *
//*                                                                   *
//*SO, IN GENERAL, KEEP THE LAST MIN(RCVTHIST, PWDCNT) ENTRIES. SET   *
//*PWDGEN AND NUMBER THE ENTRIES THAT YOU KEEP 0, 1, ..., N-1.        *
//*                                                                   *
//*AND THAT IS WHAT CUTPWHIS DOES (EXCEPT THAT RCVTHIST MAY BE OVER-  *
//*RULED BY THE PARM FIELD).                                          *
//*                                                                   *
//*********************************************************************
//CUTPWHIS EXEC PGM=CUTPWHIS       PARM=20
//STEPLIB  DD DISP=SHR,DSN=MVSGRP.TEST.APFLIB   <--- YOUR APF LIBRARY
//SYSPRINT DD SYSOUT=*
//*USERIDS  DD *,DCB=BLKSIZE=80      OPTIONALLY SELECTED USERIDS
USERID1
USERID2
//*STARTUSR DD *,DCB=BLKSIZE=80      OPTIONALLY USERID TO START FROM
USERID