crackme06

 crackme6 分析

註冊機：

#include <stdio.h>
#include <stdlib.h>

#define _DEBUG

int main (int argc, const char * argv[])
{
    // title : crackme6
    // author: edmond
    // date: 2012.6.25

    // Register Name: edmond
    // Serial: T8166813790
    char *name = "";

    // f1(Name) = mid_serial;
    char *code_table = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    char *sec_mid_serial = {0};
    int name_sum = 0;
    sec_mid_serial = malloc(strlen(name)+1);

    for (int i=0; i<strlen(name); i++)
        name_sum += name[i];
    for (int i=0; i<strlen(name); i++)
        sec_mid_serial[i] = (char)(
                                   (
                                    (
                                     ( (code_table[i*3-1]^name[i]) +
                                       (name_sum*(i-1)^0xFFFFFFFF) +
                                       0x14D +
                                       strlen(name)*(i+3)*name[i]
                                     )%10+0x30
                                    )^0xADAC
                                   )*(i+2)%10+0x30
                                  );
    char *mid_serial = malloc(100);
    sprintf(mid_serial, "T%s-%d", sec_mid_serial, (int)(strlen(name)*name_sum%0x64+0x30));

    // f2(mid_serial) = last_serial;
    char *final_serial = malloc(100);
    final_serial[0] = mid_serial[0];
    for (int i=1; i<strlen(mid_serial); i++)
        final_serial[i] = (mid_serial[i]^0x20)%10+0x30;

#ifdef _DEBUG
    printf("%s\n",final_serial);
#endif

    free(sec_mid_serial);
    free(mid_serial);
    free(final_serial);
    return 0;
}