Adobe Serial Number Decrypter

adobe-decrypt-serial.c

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

int main(int argc, const char *argv[])
{
    int i, idx;
    const char *adobe_cipher[] = {
        "0000000001", "5038647192", "1456053789", "2604371895", 
        "4753896210", "8145962073", "0319728564", "7901235846", 
        "7901235846", "0319728564", "8145962073", "4753896210", 
        "2604371895", "1426053789", "5038647192", "3267408951", 
        "5038647192", "2604371895", "8145962073", "7901235846", 
        "3267408951", "1426053789", "4753896210", "0319728564"
    };
    char decrypted_key[25] = {0};
    const char *encrypted_key;

    encrypted_key = argv[1];

    for (i = 0; i < 24; i++)
    {
        idx = encrypted_key[i] - '0';
        decrypted_key[i] = adobe_cipher[i][idx];
    }

    printf("Serial number: ");
    for (i = 0; i < 6; i++)
    {
       fwrite(&decrypted_key[i * 4], 1, 4, stdout);
       if (i != 5)
        putchar('-');
    }
    putchar('\n');

    return EXIT_SUCCESS;
}