Re: Leif's MIFHASH usage (was RE: Generate hash code for a source member?)

From: Leif Svalgaard <leif@leif.org>
> Dan,
> I'm also sending the program to you by private email.
> Below is basically what you want.

I reread the specs for CIPHER (it has been a while since I did this)
and there is a new little twist, where the Hash function x'0005' now also can
be used for message authentication. To prevent it from doing that (and only
doing the simple hashing) a new control field CTRL-OUTPUT has to be
set to x'00'. The updated program follows (I also added a few more
descriptive labels):

DCL SPCPTR .ODP;
DCL SPC     ODP BAS(.ODP);
    DCL DD  ODP.DCB  BIN(4) DEF(ODP) POS(17);

DCL SPCPTR .OPEN-FEEDBACK;
DCL SPC     OPEN-FEEDBACK BAS(.OPEN-FEEDBACK);
    DCL DD  OPEN-RECORD-LENGTH BIN(2) DEF(OPEN-FEEDBACK) POS(45);

DCL SPCPTR .DCB;
DCL SPC     DCB BAS(.DCB);
    DCL DD  DCB-GET  BIN(2) DEF (DCB) POS(25);

DCL SPCPTR .NULL;
DCL SPCPTR @SEPT BASPCO;
DCL SYSPTR .SEPT(6440) BAS(@SEPT);

DCL CON CLOSE-ENTRY BIN(2) INIT(11);
DCL CON OPEN-ENTRY  BIN(2) INIT(12);

DCL SPCPTR .IFCB INIT(IFCB);
DCL DD IFCB CHAR(211) BDRY(16);
    DCL SPCPTR .IFCB-ODP               DEF(IFCB) POS(  1);
    DCL SPCPTR .IFCB-INBUF             DEF(IFCB) POS( 17);
    DCL SPCPTR .IFCB-OPEN-FEEDBACK     DEF(IFCB) POS( 49);
    DCL DD IFCB-FILE          CHAR(10) DEF(IFCB) POS(129);
    DCL DD IFCB-LIB-ID        BIN(2)   DEF(IFCB) POS(139) INIT(72);
    DCL DD IFCB-LIBRARY       CHAR(10) DEF(IFCB) POS(141);
    DCL DD IFCB-MBR-ID        BIN(2)   DEF(IFCB) POS(151) INIT(73);
    DCL DD IFCB-MEMBER        CHAR(10) DEF(IFCB) POS(153);
    DCL DD IFCB-FLAGS-1       CHAR(1)  DEF(IFCB) POS(175) INIT(X'80');
    DCL DD IFCB-FLAGS-2       CHAR(1)  DEF(IFCB) POS(176) INIT(X'20');
    DCL DD IFCB-NO-MORE-PARMS BIN (2)  DEF(IFCB) POS(209) INIT(32767);

DCL OL  OPEN-I(.IFCB);
DCL OL CLOSE-I(.IFCB);

DCL DD GET-ENTRY BIN(2);
DCL DD INBUF  CHAR(268) BAS(.IFCB-INBUF);
DCL DD      GET-OPTION  BIN(4) INIT(H'03000001');
DCL SPCPTR .GET-OPTION         INIT(GET-OPTION);
DCL OL GET-OPERATION(.IFCB, .GET-OPTION, .NULL);

DCL EXCM * EXCID(H'5001') BP(EOF-DETECTED) CV("CPF") IMD;

DCL DD CONTROL CHAR(32) BDRY(16);
    DCL DD CTRL-FUNCTION  CHAR(2) DEF(CONTROL) POS( 1);
    DCL DD CTRL-ALGORITHM CHAR(1) DEF(CONTROL) POS( 3);
    DCL DD CTRL-SEQUENCE  CHAR(1) DEF(CONTROL) POS( 4);
    DCL DD CTRL-LENGTH     BIN(4) DEF(CONTROL) POS( 5);
    DCL DD CTRL-OUTPUT    CHAR(1) DEF(CONTROL) POS( 9);
    DCL DD *              CHAR(7) DEF(CONTROL) POS(10);
    DCL SPCPTR .WORK              DEF(CONTROL) POS(17);

DCL DD WORK CHAR(96); /* PRIVATE WORK AREA FOR CIPHER */

DCL SPCPTR .CIPHER-RESULT INIT(CIPHER-RESULT);
DCL DD      CIPHER-RESULT CHAR(20);

DCL SPCPTR .CIPHER-SOURCE INIT(CIPHER-SOURCE);
DCL DD      CIPHER-SOURCE CHAR(257);

DCL DD TEXT-LENGTH BIN(2);

DCL SPCPTR .PARM1 PARM;
DCL DD PARM-LIBRARY CHAR(10) BAS(.PARM1);

DCL SPCPTR .PARM2 PARM;
DCL DD PARM-FILE    CHAR(10) BAS(.PARM2);

DCL SPCPTR .PARM3 PARM;
DCL DD PARM-MEMBER  CHAR(10) BAS(.PARM3);

DCL SPCPTR .PARM4 PARM;
DCL DD PARM-HASH    CHAR(40) BAS(.PARM4);

DCL OL PARMS(.PARM1, .PARM2, .PARM3, .PARM4) PARM EXT MIN(4);

/**************************************************************/

ENTRY * (PARMS) EXT;

OPEN-INPUT-FILE:
    CPYBLA      IFCB-LIBRARY, PARM-LIBRARY;
    CPYBLA      IFCB-FILE,    PARM-FILE   ;
    CPYBLA      IFCB-MEMBER,  PARM-MEMBER ;
    CALLX      .SEPT(OPEN-ENTRY), OPEN-I, *;

    CPYBWP     .OPEN-FEEDBACK, .IFCB-OPEN-FEEDBACK;
    SUBN        TEXT-LENGTH,  OPEN-RECORD-LENGTH, 12;

    CPYBWP     .NULL, *; /* MAKE NULL PTR */
    CPYBWP     .ODP, .IFCB-ODP;
    ADDSPP     .DCB, .ODP, ODP.DCB;
    CPYNV       GET-ENTRY, DCB-GET;

INITIALIZE-CIPHER-CONTROL:
    CPYBLA      CTRL-FUNCTION,  X'0005'; /* HASH  */
    CPYBLA      CTRL-ALGORITHM,   X'01'; /* SHA-1 */
    CPYBLA      CTRL-OUTPUT,      X'00'; /* HASH  */
    SETSPP     .WORK, WORK;
    CPYBREP     WORK, X'00';

HASH-DUMMY-FIRST-RECORD:
    CPYBLA      CIPHER-SOURCE, " ";
    CPYNV       CTRL-LENGTH,    1;
    CPYBLA      CTRL-SEQUENCE, X'01'; /* FIRST */
    CIPHER     .CIPHER-RESULT, CONTROL, .CIPHER-SOURCE;

GET-NEXT-RECORD:
    CALLX      .SEPT(GET-ENTRY), GET-OPERATION, *;
    CPYBLAP     CIPHER-SOURCE, INBUF(13:TEXT-LENGTH), " ";

TRIM-AWAY-EXTRA-TRAILING-BLANKS:
    TRIML       CTRL-LENGTH, CIPHER-SOURCE, " ";
    ADDN(S)     CTRL-LENGTH, 1; /* LEAVE EXACTLY ONE BLANK */

HASH-REAL-MIDDLE-RECORD:
    CPYBLA      CTRL-SEQUENCE, X'02'; /* MIDDLE */
    CIPHER     .CIPHER-RESULT, CONTROL, .CIPHER-SOURCE;
    B           GET-NEXT-RECORD;

EOF-DETECTED:
    CALLX      .SEPT(CLOSE-ENTRY), CLOSE-I, *;

HASH-DUMMY-FINAL-RECORD:
    CPYBLA      CIPHER-SOURCE, " ";
    CPYNV       CTRL-LENGTH,    1;
    CPYBLA      CTRL-SEQUENCE, X'03'; /* FINAL */
    CIPHER     .CIPHER-RESULT, CONTROL, .CIPHER-SOURCE;

RETURN-WITH-RESULT:
    CVTHC       PARM-HASH, CIPHER-RESULT;
    RTX         *;

PEND;