CrackMe® Practices for Newbies
PROJECT 5: zipfile.exe

Re: Re: An workable solution. But difficult.
Wednesday, 10-Feb-99 17:50:18
    195.102.196.97 writes:

    Hi Princess


    Here is the CRC-32 routine:

    This routine calculates a running CRC-32
    value on the buffer passed to it. You
    should use proper CRC pre and post-conditioning,
    meaning an initial start value of ~0 (all ones)
    and the final value be one's complemented.
    Below is an example pseudo-code using the
    CRC 32 routine:

    unsigned long far pascal crc32(
    unsigned char far *buffer,
    unsigned short int far *size,
    unsigned long far *old_crc);

    unsigned long crc_cal = ~0;
    unsigned short int size;
    extern char far buffer[];
    /* some buffer containing */
    /* data to be CRC'd */


    while (data is being put in buffer)
    { size = amount of data in buffer;
    crc_val=crc32(buffer,&size,&crc_val);
    }

    crc_val=~crc_val;
    printf("Final CRC residual value is: %lu\n",crc_val);



    L8R Mushy!!!


    mushy


Message thread:

The Mushy thread (mushy) (09-Feb-99 16:31:15)

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