Cracking Projects For Newbies

Task 3, Q. 1
Saturday, 06-Feb-99 16:51:54
    206.248.47.206 writes:

    Task 3, Question 1

    0040B73A E881150000 call 0040CCC0 < == this is the call where the real serial # and the input serial number are compared number by number

    :0040B73F 83C408 add esp, 00000008 < == there are 8 loops in the call above when the whole serial is checked, so to keep everything in correct order so it will pop properly 8 has been added to the stack pointer (I believe .)

    :0040B742 85C0 test eax, eax < == eax will have a value when it returns from the call at 40CCC0 . This will be either 00, or 01.
    If 00 then the matching of the real generated serial and the serial we entered match. If eax was 01 then the serials do not match and we get the error screen.
    This test will set the zero flag to either on or off.
    On if 00, off if 01 ( to understand test eax, eax think of it like this test eax if zero, and don't worry about the semantics.)

    :0040B744 0F8572020000 jne 0040B9BC < == this jump will cause us to go to the "Sorry, the registration code does not match!" error message if the above test fails

    Princess


    Princess


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Princess: Princess' tread Project 6 (03-Feb-99 18:51:42)

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