String changer working program but needs some polishing

andrewkennedy1_at_ev1.net
Date: 01/31/04 

Date: Sat, 31 Jan 2004 00:21:53 -0000

Just posted relevant sections.

Few questions though.

What if sting isn't evenly divisible by 2.

Would the program still work if all the chars were still there but in
wrong order?

     Andrew Kennedy

andrewkennedy2@ev1LOG.net
To respond by email remove the LOG from the address.

DETA_it db " Don't hex with me"
       afraid_not db 13,10,'File has been tampered with!!',13,10
                   db 13,10,'Now aborting...$'
                   
;string_changer: ; NEED TO CHECK VALUE OF STRING AND COMPARE AGAINST
                ; A STORED VALUE
                ; WE COULD ENCRYPT THE VALUE AND HIDE IT IN THE CODE SECTION
                ; BUT I'M JUST TRYING TO STOP GENERIC "HEXERS"
                ; If they restore it back to original it'll work again
     xor cx,cx
     mov cx, 9 ; count = string bytes / 2
     mov si, offset [DETA_it] ; address of start-of-strings
     xor ax, ax
more:
     xor ax, [si]
     inc si
     inc si
     dec cx
     jnz more
     cmp ax, 0861h ; previously calc'd value of string
     je short message

      mov dx,offset afraid_not
      mov ah,9
      int 21h

     mov ax, 4c01h
     int 21h ; abort

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