Mac OS 9 Serial Number Archive/SN Archive 2023.11.04.toast/BSNG/Plugins/TSNG Contributor/CDFinder/CDFinder Plugin ReadMe.c

Text File | 1997-12-19 | 26.5 KB | 450 lines | [TEXT/R*ch]

/*
Analyzing CDFinder 2.0's SN# algorithm was _highly entertaining_, the author has obviously seen C&N or some such lists entry for CDFinder and has added distributed
checks (except for a minor mistake -- documented with correction below) for the pirate user names "NASA" and "MoonDark".  What was especially entertaining
is how predictable this guy thinks, appart from the naming conventions I bet the following source code is 99.8% _exactly the same_ as the authors.  The
birthdate, authors initials and "PV" = "Pirated Version" insights were bonuses, but the icing on the cake was the logic error in the "MoonDark" test.  I
don't even use the program in question, but as soon as soon as I saw the check code I could see it was interesting so I just had to reverse engineer it.
I hope everyone gets a kick out of this -- MoonDark, especially, should find this funny.  Enclosed at the end is the 68K assembly source dump so you can
see what I'm describing first hand.
*/

//A5 Globals - these are checked and/or used after by the main registration logic.

UInt16    globA5Minus0x0DD6 = 0;    //global that is set to its correct value of 0x07AE iff chars 2,5,9, and 10 of snStr[] are the correct digits
UInt32    globA5Minus0x0DD4;        //holds final nameStr hash value
UInt16    globA5Minus0x0DD0 = 0;    //global that is set to its correct value of 0x0007 iff chars 1 and 7 of snStr[] are correct [note this is the authors (Norbert Doerner) initials]
UInt16    globA5Minus0x0DCE = 0;    //global that is set to its correct value of 0x000D iff chars 3,4,6, and 8 of snStr[] are the correct digits

//notice the magic correct numbers uniquely define the date 1966/07/13, which is almost undoubtedly the author's (or his girlfriend's) birthdate.

//this is a more or less direct translation of the assembly code.
//when combined with the assembly source below is a very good tutorial/example to learn from, especially for those that have difficulty following
//intricate sequences of integer math operations.
//the following returns 1 iff a pirate user name was used, otherwise it returns 0 - it also does almost all the work of validating a serial number
UInt16    Check1CDFinder2SN(Str255 nameStr, Str15 snStr);
UInt16    Check1CDFinder2SN(Str255 nameStr, Str15 snStr)
{
UInt32        d3 = 1;                //flag indicating pirate user name "\pMoonDark" (actually the author made an error in the source code that checks for "oo" in "MoonDark", see below for explanation)
UInt32        d4 = 1;                //flag indicating pirate user name "\pNASA"
SInt32        d5;
UInt32        d7 = 0;
UInt32        d6 = (UInt8) nameStr[0];
SInt32        u, v, w, d7;
Str255        xStr;

    globA5Minus0x0DCE = 0;
    if (nameStr[0] == 0) return 0;
    if (nameStr[0] != 4) d4 = 0;
    if (nameStr[0] != 8) d3 = 0;

    for (d5 = d6; d5 > 0 ; d5--)                                        //this loop calculates a partial hash of the nameStr
    {
        u    = 7UL * (UInt32) (d5 * 17L);                                //note the UInt32 multiply
        v    = (SInt16) ((u / 13L) * 831L);                                //note the SInt16 sign extend
        w    = ((v * (v + 4097L)) / 83L) * 137L;
        d7 += (((SInt16) v / (SInt16) w) + u) * (UInt8) nameStr[d5];    //note the SInt16 divide then extend

    }
    if ((nameStr[8] != 'k') && (d3 != 0)) d3 = 0;            //note: the last part of the conditional expression is unecessary
    if ((nameStr[2] != nameStr[4]) && (d4 != 0)) d4 = 0;    //note: the last part of the conditional expression is unecessary
    d5 = d7 * 53L;

    //the following code should be present here, but due to a parenthesization/logic error in the authors code it is always false and thus never executed
    //if (((nameStr[2] != nameStr[3]) || (nameStr[2] != 'o')) && (d3 != 0)) d3 = 0;    //note: the last part of the conditional expression is unecessary

    //in actuality the author wrote something like this:
    //if (((nameStr[2] != nameStr[3]) == 'o') && (d3 != 0)) d3 = 0;
    //of course the == 'o' condition is always false, thus any user name of the form "M**nDark", where '*' is any character, is in fact also illegal.

    if ((nameStr[4] != 'A') && (d4 != 0)) d4 = 0;            //note: the last part of the conditional expression is unecessary
    NumToString(d5 * 7L, xStr);
    globA5Minus0x0DD4 = d5 * 7L;
    if ((nameStr[3] != 'S') && (d4 != 0)) d4 = 0;            //note: the last part of the conditional expression is unecessary
    d6 = xStr[0];

    if ((nameStr[1] != 'M') && (d3 != 0)) d3 = 0;            //note: the last part of the conditional expression is unecessary
    if (snStr[0] != 10) return 1;
    if ((nameStr[1] != 'N') && (d4 != 0)) d4 = 0;            //note: the last part of the conditional expression is unecessary
    if (xStr[0] < 8)                                        //extend the hashed string to at least 8 chars in a nonstandard way
    {
        for (d5 = xStr[0] + 1; d5 <= 8; d5++) xStr[d5] = xStr[1];
        xStr[0] = 8;
    }

    if ((nameStr[4] != 'n') && (d3 != 0)) d3 = 0;            //note: the last part of the conditional expression is unecessary
    if (d4 != 0)            //note that at this point (d4 != 0) implies that nameStr[] = "\pNASA"
    {
        xStr[5]        = 'P';    //no doubt this stands for "Pirated Version"
        snStr[7]    = 'V';
        return 1;            //pirate name was used
    }
    if ((nameStr[5] != 'D') && (d3 != 0)) d3 = 0;            //note: the last part of the conditional expression is unecessary
    if (snStr[ 2] != xStr[5]) goto LB1;
    if (snStr[ 9] != xStr[2]) goto LB1;
    if (snStr[ 5] != xStr[7]) goto LB1;
    if (snStr[10] != xStr[6]) goto LB1;
    globA5Minus0x0DD6 = 0x07AE;        //chars 2,5,9, and 10 of snStr[] are the correct digits
LB1:
    if ((nameStr[7] != 'r') && (d3 != 0)) d3 = 0;            //note: the last part of the conditional expression is unecessary
    if (snStr[7] != 'D') goto LB2;                    //Doerner
    if (snStr[1] != 'N') goto LB2;                    //Norbert
    globA5Minus0x0DD0 = 0x0007;        //chars 1 and 7 of snStr[] are correct [note this is the authors (Norbert Doerner) initials]
LB2:
    if ((nameStr[6] != 'a') && (d3 != 0)) d3 = 0;            //note: the last part of the conditional expression is unecessary
    if (snStr[ 4] != xStr[4]) goto LB3;
    if (snStr[ 6] != xStr[3]) goto LB3;
    if (snStr[ 8] != xStr[1]) goto LB3;
    if (snStr[ 3] != xStr[8]) goto LB3;
    globA5Minus0x0DCE = 0x000D;        //chars 3,4,6, and 8 of snStr[] are the correct digits
LB3:
    if (d3 != 0)            //note that at this point (d3 != 0) implies that nameStr[] = "\pM**nDark"
    {
        xStr[5]        = 'P';    //no doubt this stands for "Pirated Version"
        snStr[7]    = 'V';
        return 1;            //pirate name was used
    }
    if (d4 != 0) return d4;    //the author was unsure of himself and added this extraneous check (d4 is always zero here)
    return 0;    //pirate name was not used
}

//The following is a 68K assembly dump of the authors code corresponding to the above
/*
+08C1A 0527837A   LINK       A6,#$FFC0
+08C1E 0527837E   MOVEM.L    D3-D7/A2/A3,-(A7)
+08C22 05278382   MOVEA.L    $0008(A6),A2
+08C26 05278386   MOVEA.L    $000C(A6),A3
+08C2A 0527838A   MOVEQ      #$01,D4
+08C2C 0527838C   MOVEQ      #$00,D6
+08C2E 0527838E   MOVE.B     (A2),D6
+08C30 05278390   CLR.W      -$0DCE(A5)
+08C34 05278394   TST.B      (A2)
+08C36 05278396   BNE.S      'CODE 0001 25…urces'+08C3E ; 0527839E
+08C38 05278398   MOVEQ      #$00,D0
+08C3A 0527839A   BRA        'CODE 0001 25…urces'+08E1E ; 0527857E
+08C3E 0527839E   MOVEQ      #$01,D3
+08C40 052783A0   MOVEQ      #$00,D7
+08C42 052783A2   MOVEQ      #$04,D0
+08C44 052783A4   CMP.L      D0,D6
+08C46 052783A6   BEQ.S      'CODE 0001 25…urces'+08C4A ; 052783AA
+08C48 052783A8   MOVEQ      #$00,D4
+08C4A 052783AA   MOVEQ      #$08,D0
+08C4C 052783AC   CMP.L      D0,D6
+08C4E 052783AE   BEQ.S      'CODE 0001 25…urces'+08C52 ; 052783B2
+08C50 052783B0   MOVEQ      #$00,D3
+08C52 052783B2   MOVE.L     D6,D5
+08C54 052783B4   BRA.S      'CODE 0001 25…urces'+08C76 ; 052783D6
+08C56 052783B6      //contents of this math loop are given below - it is quit interesting actually
+08C72 052783D2   SUBQ.L     #$1,D5
+08C74 052783D4   ADDQ.W     #$4,A7
+08C76 052783D6   TST.L      D5
+08C78 052783D8   BGT.S      'CODE 0001 25…urces'+08C56 ; 052783B6
+08C7A 052783DA   CMPI.B     #$6B,$0008(A2)             ; 'k'
+08C80 052783E0   BEQ.S      'CODE 0001 25…urces'+08C88 ; 052783E8
+08C82 052783E2   TST.L      D3
+08C84 052783E4   BEQ.S      'CODE 0001 25…urces'+08C88 ; 052783E8
+08C86 052783E6   MOVEQ      #$00,D3
+08C88 052783E8   MOVE.B     $0002(A2),D0
+08C8C 052783EC   CMP.B      $0004(A2),D0
+08C90 052783F0   BEQ.S      'CODE 0001 25…urces'+08C98 ; 052783F8
+08C92 052783F2   TST.L      D4
+08C94 052783F4   BEQ.S      'CODE 0001 25…urces'+08C98 ; 052783F8
+08C96 052783F6   MOVEQ      #$00,D4
+08C98 052783F8   MOVEQ      #$35,D5                    ; '5'
+08C9A 052783FA   MULS.L     D7,D5
+08C9E 052783FE   MOVE.B     $0002(A2),D0
+08CA2 05278402   CMP.B      $0003(A2),D0
+08CA6 05278406   SEQ        D0                                      //• this is where the "MoonDark" logic error is
+08CA8 05278408   NEG.B      D0                                      //• this is where the "MoonDark" logic error is
+08CAA 0527840A   CMPI.B     #$6F,D0                    ; 'o'
+08CAE 0527840E   BNE.S      'CODE 0001 25…urces'+08CB6 ; 05278416
+08CB0 05278410   TST.L      D3
+08CB2 05278412   BEQ.S      'CODE 0001 25…urces'+08CB6 ; 05278416
+08CB4 05278414   MOVEQ      #$00,D3
+08CB6 05278416   CMPI.B     #$41,$0004(A2)             ; 'A'
+08CBC 0527841C   BEQ.S      'CODE 0001 25…urces'+08CC4 ; 05278424
+08CBE 0527841E   TST.L      D4
+08CC0 05278420   BEQ.S      'CODE 0001 25…urces'+08CC4 ; 05278424
+08CC2 05278422   MOVEQ      #$00,D4
+08CC4 05278424   MOVEQ      #$07,D0
+08CC6 05278426   MULS.L     D5,D0
+08CCA 0527842A   MOVE.L     D0,-(A7)
+08CCC 0527842C   PEA        -$0040(A6)
+08CD0 05278430   JSR        'CODE 0003 25…aries'+023D6              //this is just a NumToString call
+08CD6 05278436   MOVEQ      #$07,D0
+08CD8 05278438   MULS.L     D5,D0
+08CDC 0527843C   MOVE.L     D0,-$0DD4(A5)
+08CE0 05278440   CMPI.B     #$53,$0003(A2)             ; 'S'
+08CE6 05278446   BEQ.S      'CODE 0001 25…urces'+08CEE ; 0527844E
+08CE8 05278448   TST.L      D4
+08CEA 0527844A   BEQ.S      'CODE 0001 25…urces'+08CEE ; 0527844E
+08CEC 0527844C   MOVEQ      #$00,D4
+08CEE 0527844E   MOVEQ      #$00,D6
+08CF0 05278450   MOVE.B     -$0040(A6),D6
+08CF4 05278454   CMPI.B     #$4D,$0001(A2)             ; 'M'
+08CFA 0527845A   BEQ.S      'CODE 0001 25…urces'+08D02 ; 05278462
+08CFC 0527845C   TST.L      D3
+08CFE 0527845E   BEQ.S      'CODE 0001 25…urces'+08D02 ; 05278462
+08D00 05278460   MOVEQ      #$00,D3
+08D02 05278462   CMPI.B     #$0A,(A3)
+08D06 05278466   BEQ.S      'CODE 0001 25…urces'+08D0E ; 0527846E
+08D08 05278468   MOVEQ      #$01,D0
+08D0A 0527846A   BRA        'CODE 0001 25…urces'+08E1E ; 0527857E
+08D0E 0527846E   CMPI.B     #$4E,$0001(A2)             ; 'N'
+08D14 05278474   BEQ.S      'CODE 0001 25…urces'+08D1C ; 0527847C
+08D16 05278476   TST.L      D4
+08D18 05278478   BEQ.S      'CODE 0001 25…urces'+08D1C ; 0527847C
+08D1A 0527847A   MOVEQ      #$00,D4
+08D1C 0527847C   MOVEQ      #$08,D0
+08D1E 0527847E   CMP.L      D0,D6
+08D20 05278480   BGE.S      'CODE 0001 25…urces'+08D40 ; 052784A0
+08D22 05278482   MOVE.B     #$08,-$0040(A6)
+08D28 05278488   MOVE.L     D6,D5
+08D2A 0527848A   ADDQ.L     #$1,D5
+08D2C 0527848C   BRA.S      'CODE 0001 25…urces'+08D3A ; 0527849A
+08D2E 0527848E   LEA        -$0040(A6),A0
+08D32 05278492   MOVE.B     -$003F(A6),$00(A0,D5.L)
+08D38 05278498   ADDQ.L     #$1,D5
+08D3A 0527849A   MOVEQ      #$08,D0
+08D3C 0527849C   CMP.L      D0,D5
+08D3E 0527849E   BLE.S      'CODE 0001 25…urces'+08D2E ; 0527848E
+08D40 052784A0   CMPI.B     #$6E,$0004(A2)             ; 'n'
+08D46 052784A6   BEQ.S      'CODE 0001 25…urces'+08D4E ; 052784AE
+08D48 052784A8   TST.L      D3
+08D4A 052784AA   BEQ.S      'CODE 0001 25…urces'+08D4E ; 052784AE
+08D4C 052784AC   MOVEQ      #$00,D3
+08D4E 052784AE   TST.L      D4
+08D50 052784B0   BEQ.S      'CODE 0001 25…urces'+08D64 ; 052784C4
+08D52 052784B2   MOVE.B     #$50,-$003B(A6)            ; 'P'
+08D58 052784B8   MOVE.B     #$56,$0007(A3)             ; 'V'
+08D5E 052784BE   MOVEQ      #$01,D0
+08D60 052784C0   BRA        'CODE 0001 25…urces'+08E1E ; 0527857E
+08D64 052784C4   CMPI.B     #$44,$0005(A2)             ; 'D'
+08D6A 052784CA   BEQ.S      'CODE 0001 25…urces'+08D72 ; 052784D2
+08D6C 052784CC   TST.L      D3
+08D6E 052784CE   BEQ.S      'CODE 0001 25…urces'+08D72 ; 052784D2
+08D70 052784D0   MOVEQ      #$00,D3
+08D72 052784D2   MOVE.B     -$003B(A6),D0
+08D76 052784D6   CMP.B      $0002(A3),D0
+08D7A 052784DA   BNE.S      'CODE 0001 25…urces'+08DA0 ; 05278500
+08D7C 052784DC   MOVE.B     -$003E(A6),D0
+08D80 052784E0   CMP.B      $0009(A3),D0
+08D84 052784E4   BNE.S      'CODE 0001 25…urces'+08DA0 ; 05278500
+08D86 052784E6   MOVE.B     -$0039(A6),D0
+08D8A 052784EA   CMP.B      $0005(A3),D0
+08D8E 052784EE   BNE.S      'CODE 0001 25…urces'+08DA0 ; 05278500
+08D90 052784F0   MOVE.B     -$003A(A6),D0
+08D94 052784F4   CMP.B      $000A(A3),D0
+08D98 052784F8   BNE.S      'CODE 0001 25…urces'+08DA0 ; 05278500
+08D9A 052784FA   MOVE.W     #$07AE,-$0DD6(A5)
+08DA0 05278500   CMPI.B     #$72,$0007(A2)             ; 'r'
+08DA6 05278506   BEQ.S      'CODE 0001 25…urces'+08DAE ; 0527850E
+08DA8 05278508   TST.L      D3
+08DAA 0527850A   BEQ.S      'CODE 0001 25…urces'+08DAE ; 0527850E
+08DAC 0527850C   MOVEQ      #$00,D3
+08DAE 0527850E   CMPI.B     #$44,$0007(A3)             ; 'D'
+08DB4 05278514   BNE.S      'CODE 0001 25…urces'+08DC4 ; 05278524
+08DB6 05278516   CMPI.B     #$4E,$0001(A3)             ; 'N'
+08DBC 0527851C   BNE.S      'CODE 0001 25…urces'+08DC4 ; 05278524
+08DBE 0527851E   MOVE.W     #$0007,-$0DD0(A5)
+08DC4 05278524   CMPI.B     #$61,$0006(A2)             ; 'a'
+08DCA 0527852A   BEQ.S      'CODE 0001 25…urces'+08DD2 ; 05278532
+08DCC 0527852C   TST.L      D3
+08DCE 0527852E   BEQ.S      'CODE 0001 25…urces'+08DD2 ; 05278532
+08DD0 05278530   MOVEQ      #$00,D3
+08DD2 05278532   MOVE.B     -$003C(A6),D0
+08DD6 05278536   CMP.B      $0004(A3),D0
+08DDA 0527853A   BNE.S      'CODE 0001 25…urces'+08E00 ; 05278560
+08DDC 0527853C   MOVE.B     -$003D(A6),D0
+08DE0 05278540   CMP.B      $0006(A3),D0
+08DE4 05278544   BNE.S      'CODE 0001 25…urces'+08E00 ; 05278560
+08DE6 05278546   MOVE.B     -$003F(A6),D0
+08DEA 0527854A   CMP.B      $0008(A3),D0
+08DEE 0527854E   BNE.S      'CODE 0001 25…urces'+08E00 ; 05278560
+08DF0 05278550   MOVE.B     -$0038(A6),D0
+08DF4 05278554   CMP.B      $0003(A3),D0
+08DF8 05278558   BNE.S      'CODE 0001 25…urces'+08E00 ; 05278560
+08DFA 0527855A   MOVE.W     #$000D,-$0DCE(A5)
+08E00 05278560   TST.L      D3
+08E02 05278562   BEQ.S      'CODE 0001 25…urces'+08E14 ; 05278574
+08E04 05278564   MOVE.B     #$50,-$003B(A6)            ; 'P'
+08E0A 0527856A   MOVE.B     #$56,$0007(A3)             ; 'V'
+08E10 05278570   MOVEQ      #$01,D0
+08E12 05278572   BRA.S      'CODE 0001 25…urces'+08E1E ; 0527857E
+08E14 05278574   TST.L      D4
+08E16 05278576   BEQ.S      'CODE 0001 25…urces'+08E1C ; 0527857C
+08E18 05278578   MOVE.B     D4,D0
+08E1A 0527857A   BRA.S      'CODE 0001 25…urces'+08E1E ; 0527857E
+08E1C 0527857C   MOVEQ      #$00,D0
+08E1E 0527857E   MOVEM.L    (A7)+,D3-D7/A2/A3
+08E22 05278582   UNLK       A6
+08E24 05278584   RTS

//Math contained inside the 'Math loop', note code is linear with no branching
//thus you may read top to bottom as if the jsr/bsr are not there
//ie. I have traced thru and listed the code in the order it executes.
//notice that there is some very subtle type changing going on…
//specifically almost all the math is signed long, but watch out for the
//exceptions -- they are critical

+08C56 053405D6   MOVEQ      #$11,D0
+08C58 053405D8   MULS.L     D5,D0
+08C5C 053405DC   MOVE.L     D0,-(A7)

+08C5E 053405DE   BSR.L      'CODE 0001 25…urces'+08E26 ; 053407A6

+08E26 053407A6   LINK       A6,#$FFFC
+08E2A 053407AA   MOVE.L     D3,-(A7)
+08E2C 053407AC   MOVEQ      #$07,D3
+08E2E 053407AE   MULU.L     $0008(A6),D3                            //••• exception
+08E34 053407B4   MOVE.L     D3,D0
+08E36 053407B6   DIVS.L     #$0000000D,D0
+08E3E 053407BE   MULS.L     #$0000033F,D0
+08E46 053407C6   MOVE.L     D0,-$0004(A6)
+08E4A 053407CA   MOVE.W     -$0002(A6),-(A7)
+08E4E 053407CE   MOVE.L     D3,-(A7)
+08E50 053407D0   JSR        'CODE 0001 25…urces'+08BBC ; 0534053C

+08BBC 0534053C   LINK       A6,#$0000
+08BC0 05340540   MOVE.W     $000C(A6),-(A7)
+08BC4 05340544   BSR.L      'CODE 0001 25…urces'+08BDE ; 0534055E

+08BDE 0534055E   LINK       A6,#$FFFC
+08BE2 05340562   MOVE.L     D5,-(A7)
+08BE4 05340564   MOVE.W     $0008(A6),D5
+08BE8 05340568   MOVEQ      #$53,D2                    ; 'S'
+08BEA 0534056A   MOVEA.W    D5,A0                                   //••• exception, sign extension is implicit here
+08BEC 0534056C   MOVE.L     A0,D1
+08BEE 0534056E   ADDI.L     #$00001001,D1
+08BF4 05340574   MOVE.L     D1,D0
+08BF6 05340576   ADD.L      A0,D0
+08BF8 05340578   MOVE.L     D0,-$0004(A6)
+08BFC 0534057C   MOVE.L     A0,D0
+08BFE 0534057E   MULS.L     D1,D0
+08C02 05340582   DIVS.L     D2,D0
+08C06 05340586   MOVE.L     D0,D2
+08C08 05340588   MOVE.L     #$00000089,D1
+08C0E 0534058E   MOVE.L     D1,D0
+08C10 05340590   MULS.L     D2,D0
+08C14 05340594   MOVE.L     (A7)+,D5
+08C16 05340596   UNLK       A6
+08C18 05340598   RTS

+08BCA 0534054A   MOVEA.W    $000C(A6),A0
+08BCE 0534054E   MOVE.L     A0,D1
+08BD0 05340550   DIVS.W     D0,D1                                   //••• exception
+08BD2 05340552   EXT.L      D1
+08BD4 05340554   ADD.L      $0008(A6),D1
+08BD8 05340558   MOVE.W     D1,D0
+08BDA 0534055A   UNLK       A6
+08BDC 0534055C   RTS

+08E54 053407D4   EXT.L      D0
+08E56 053407D6   ADDQ.W     #$6,A7
+08E58 053407D8   MOVE.L     (A7)+,D3
+08E5A 053407DA   UNLK       A6
+08E5C 053407DC   RTS

+08C64 053405E4   MOVEQ      #$00,D1
+08C66 053405E6   MOVE.B     $00(A2,D5.L),D1
+08C6A 053405EA   EXT.L      D1
+08C6C 053405EC   MULS.L     D0,D1
+08C70 053405F0   ADD.L      D1,D7


//this is the main registration logic that calls the above
'CODE 0001 25D4 Sources'
+089F2 05278152   PEA        -$0084(A6)
+089F6 05278156   PEA        -$0044(A6)
+089FA 0527815A   BSR.L      'CODE 0001 25…urces'+08C1A ; 0527837A   //call the checking routine
+08A00 05278160   SUBQ.B     #$1,D0
+08A02 05278162   ADDQ.W     #$8,A7
+08A04 05278164   BNE.S      'CODE 0001 25…urces'+08A1E ; 0527817E   //will branch if user name was ok
+08A06 05278166   CLR.W      -$0DD0(A5)
+08A0A 0527816A   MOVE.W     #$FFFF,-$0DCE(A5)
+08A10 05278170   BSR.L      'CODE 0001 25…urces'+08A76 ; 052781D6
+08A16 05278176   MOVE.W     #$000B,-$0DD6(A5)
+08A1C 0527817C   MOVEQ      #$01,D5
+08A1E 0527817E   CMPI.W     #$0007,-$0DD0(A5)                      //check for correct magic globals combination starts here
+08A24 05278184   BEQ.S      'CODE 0001 25…urces'+08A2E ; 0527818E
+08A26 05278186   CMPI.W     #$000D,-$0DCE(A5)
+08A2C 0527818C   BNE.S      'CODE 0001 25…urces'+08A38 ; 05278198
+08A2E 0527818E   CMPI.W     #$07AE,-$0DD6(A5)
+08A34 05278194   BNE.S      'CODE 0001 25…urces'+08A38 ; 05278198
+08A36 05278196   MOVEQ      #$01,D4
+08A38 05278198   TST.B      D4
+08A3A 0527819A   BNE.S      'CODE 0001 25…urces'+08A4C ; 052781AC
+08A3C 0527819C   TST.B      D5
+08A3E 0527819E   BNE.S      'CODE 0001 25…urces'+08A4C ; 052781AC
+08A40 052781A0   MOVE.W     #$0002,-(A7)
+08A44 052781A4   BSR.L      'CODE 0001 25…urces'+00CC0 ; 05270420
+08A4A 052781AA   ADDQ.W     #$2,A7
+08A4C 052781AC   TST.B      D4
+08A4E 052781AE   BEQ        'CODE 0001 25…urces'+0892C ; 0527808C
+08A52 052781B2   PEA        -$0084(A6)
+08A56 052781B6   PEA        -$0044(A6)
+08A5A 052781BA   BSR.L      'CODE 0001 25…urces'+06560 ; 05275CC0
+08A60 052781C0   MOVE.W     #$0001,-(A7)
+08A64 052781C4   BSR.L      'CODE 0001 25…urces'+00CC0 ; 05270420
+08A6A 052781CA   LEA        $000A(A7),A7
+08A6E 052781CE   MOVEM.L    (A7)+,D3-D5
+08A72 052781D2   UNLK       A6
+08A74 052781D4   RTS
*/


//this is needed for the generator, which is below
static Boolean myEqualPStrWithWildcardPStr(const Str255 s, const Str255 t);
static Boolean myEqualPStrWithWildcardPStr(const Str255 s, const Str255 t)
{
UInt8    *p = (UInt8 *) s;
UInt8    *q = (UInt8 *) t;
UInt8    *r = &p[p[0] + 1];

    if (*(p++) != *(q++)) return FALSE;
    if (p != r) while (((*p == *q) || (*q == '*')) && (++p != r)) ++q;
    return (Boolean) (p == r);
}


static void Generate1CDFinder2SN(const Str255 nameStr, Str15 snStr);
static void Generate1CDFinder2SN(const Str255 nameStr, Str15 snStr)
{
SInt32        len = (UInt8) nameStr[0];
SInt32        i, u, v, w, x    = 0;
Str15        xStr;


    if ((len == 0) || myEqualPStr(nameStr, "\pNASA") || myEqualPStrWithWildcardPStr(nameStr, "\pM**nDark"))
    {
        snStr[0] = 0;
        return;
    }
    for (i = len; i > 0 ; i--)
    {
        u = 7UL * (UInt32) (i * 17L);                                //note the UInt32 multiply
        v = (SInt16) ((u / 13L) * 831L);                            //note the SInt16 sign extend
        w = ((v * (v + 4097L)) / 83L) * 137L;
        x+= (((SInt16) v / (SInt16) w) + u) * (UInt8) nameStr[i];    //note the SInt16 divide then extend
    }
    x*= 53L;
    x*=  7L;
    NumToString(x, xStr);
    if (xStr[0] < 8)            //extend xStr to 8 chars in a nonstandard way
    {
        for (i = xStr[0] + 1; i <= 8; i++) xStr[i] = xStr[1];
        xStr[0] = 8;
    }
    snStr[ 0] = 10;
    snStr[ 1] = 'N';                    //Norbert
    snStr[ 2] = xStr[5];
    snStr[ 3] = xStr[8];
    snStr[ 4] = xStr[4];
    snStr[ 5] = xStr[7];
    snStr[ 6] = xStr[3];
    snStr[ 7] = 'D';                    //Doerner
    snStr[ 8] = xStr[1];
    snStr[ 9] = xStr[2];
    snStr[10] = xStr[6];
}