Thread: I do not do a lot of programing but ...

Would really love some help on getting this working.

I was given the decrypt function and was trying to build the shell. I really don't remember my pointers and references, but think it is close...

Please help! - Thanks!

Code:

#include <stdio.h>

void decrypt();

int main() {
char in[255] = "NpfTvZKQKlM8Jh19/vI";

decrypt(in);

}

int index(char *x) {
   char encIndex[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

// Not sure how to reference the array, but I believe I need to take in a char and return
// an int.

return 0;
}
void decrypt (char *in)
{
    char first, second, third, fourth;
    int lf_count = 0,
        i        = 0;
    int byte_count = strlen(in);
    while (byte_count > 0)
    {
        first  = index(&in[i]);
        second = index(&in[i + 1]);
        third  = index(&in[i + 2]);
        fourth = index(&in[i + 3]);

        if (byte_count > 2)
            first = (first << 2) | (second >> 4);
        else
            first = (first << 2);

        printf("%c", first);

        if (byte_count > 2)
        {
            if (byte_count > 3)
                second = (second << 4) | (third >> 2);
            else
                second = (second << 4);
        }

        printf("%c", second);

        if (byte_count > 3)
        {
            third = (third << 6) | fourth;
            printf("%c", third);
        }

        i += 4;
        byte_count -= 4;
        lf_count++;
    }
}