.model  tiny
.386
Org 100h
.data

INTRONAME     db 13,10,'Crypto v3.1 - Key Generator by Quantico [mEX/c4N]',13,10
              db 13,10,'Enter your name : ','$',13,10

COMPANY       db 13,10,'Enter your company : ','$',13,10

DUMBO         db 13,10,'You must enter something...',13,10,'$'


STORENAME     db 18h, 19h dup(0)
STORECOMP     db 18h, 19h dup(0)

THEIRCODE     db 13,10,'Your code is : '
STORECODE     db 10 dup(0),13,10,'$'

DATATABLE1    db '#serB&nz|mfM1/5(!sd$Mq.{s]+sFjtKpzSdtzoXqmb^Al@dv:s?x/'
DATATABLE2    db '|b!pz*ls;rn|lf$vi^Axpe)rx5aic&9/2m5lsi4@0dmZw94cmqpfhw'

Convert_Digs  db '0123456789ABCDEF'

.code
.startup

MAIN PROC    NEAR

     MOV     AH, 09h
     MOV     DX, OFFSET INTRONAME
     INT     21h                        ; show the lovely intro and
                                        ; ask for our name
     MOV     AH, 0Ah
     MOV     DX, OFFSET STORENAME
     INT     21h                        ; get what they typed
     CMP     BYTE PTR [STORENAME+1], 0  ; did they enter nothing ?
     JE      DUMB                       ; then tell them

     MOV     AH, 09h  
     MOV     DX, OFFSET COMPANY       ; ask for company
     INT     21h

     MOV     AH, 0Ah
     MOV     DX, OFFSET STORECOMP
     INT     21h                        ; get input
     CMP     BYTE PTR [STORECOMP+1], 0  ; enter nothing ?
     JE      DUMB                       ; tell them

     CALL    MAKEKEY                    ; the main procedure

     MOV     AH, 09h
     MOV     DX, OFFSET THEIRCODE       ; show them the code
     INT     21h
     JMP     FINISH                     ; go to quit

DUMB:
     MOV    AH, 09h
     MOV    DX, OFFSET DUMBO            ; tell them to enter something
     INT    21h

FINISH:
     MOV    AH, 4Ch
     INT    21h                         ; quit program

MAIN ENDP

MAKEKEY  PROC   NEAR

     MOV     ESI, 0C69AA96Ch            ; esi = C69AA96C
     OR      ESI, 000000378h            ; 
     PUSH    ESI                        ; save result for use later
     LEA     ESI, STORENAME+2           ; esi = name
     MOVSX   EAX, BYTE PTR [ESI-1]      ; eax = namelength
     CALL    NEXTSTAGE                  ; make first calculations
     POP     ESI                        ; restore esi
     ADD     ESI, EAX                   ; then add the call result
     PUSH    ESI                        ; save it again
     LEA     ESI, STORECOMP+2           ; esi = company
     MOVSX   EAX, BYTE PTR [ESI-1]      ; eax = companylength
     CALL    NEXTSTAGE                  ; make second calculations
     POP     ESI                        ; restore esi
     ADD     EAX, ESI                   ; add both parts

     XOR     EBX, EBX                   ; clear ebx
     XOR     EDX, EDX                   ; clear edx
     MOV     EDI, OFFSET STORECODE      ; place to put the string of the code
     MOV     ECX, 10d                   ; number base 10
     CALL    convert_num                ; number2string so we can print it
     RET                                ; return
MAKEKEY ENDP

NEXTSTAGE  PROC   NEAR
     XOR     EDI, EDI
     XOR     ECX, ECX
GETMORE:
     MOVSX   EBX, BYTE PTR [EAX+ECX+DATATABLE1]
     MOVSX   EBP, BYTE PTR [ECX+ESI]
     LEA     EDX, DWORD PTR [ECX+01]
     IMUL    EBX, EBP
     MOVSX   ECX, BYTE PTR [ECX+DATATABLE2]
     IMUL    EBX, ECX
     IMUL    EBX, EDX
     ADD     EDI, EBX
     MOV     ECX, EDX
     CMP     EDX, EAX                  ; end of input ?
     JL      GETMORE                   ; if not, go for more
     MOV     EAX, EDI                  ; eax = call result
     RET
NEXTSTAGE  ENDP

Convert_Num proc near
        pushf
        pushAD

        sub     esp, 4
        mov     ebp,esp

        cld
        mov     esi, edi
        push    esi

;--- loop for each digit

        sub     bh, bh
        mov     dword ptr [ebp], eax            ;save low word
        mov     dword ptr [ebp+4], edx          ;save high word
        sub     esi, esi                        ;count digits

Connum1:
        inc     esi
        mov     eax, dword ptr [ebp+4]          ;high word of value
        sub     edx, edx                        ;clear for divide
        div     ecx                             ;divide, DX gets remainder
        mov     dword ptr [ebp+4],eax           ;save quotient (new high word)

        mov     eax, dword ptr [ebp]            ;low word of value
        div     ecx                             ;divide, DX gets remainder
                                                ;  (the digit)
        mov     dword ptr [ebp], eax            ;save quotient (new low word)

        mov     bl, dl
        mov     al, byte ptr [Convert_Digs+ebx]  ;get the digit
        stosb                                       ;store

        cmp     dword ptr [ebp], 0                  ;check if low word zero
        jne     Connum1                             ;jump if not
        cmp     dword ptr [ebp+4], 0                ;check if high word zero
        jne     Connum1                             ;jump if not

        sub     al, al
        stosb                                       ;store the terminator

;--- reverse digits

        pop     ecx                          ;restore start of string
        xchg    ecx, esi
        shr     ecx, 1                       ;number of reverses
        jz      Connum3                      ;jump if none

        xchg    edi, esi
        sub     esi, 2                       ;point to last digit

Connum2 :
        mov     al, byte ptr [edi]           ;load front character
        xchg    al, byte ptr [esi]           ;swap with end character
        stosb                                ;store new front character
        dec     esi                          ;back up
        loopd   Connum2                      ;loop back for each digit

;--- finished

Connum3  :
        add     esp, 4

        popad
        popf
        ret
 endp           ;Convert_Num

END MAIN