Crack Final

#include <stdio.h>
#include <cs50.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <crypt.h>

// easy passwords for testing:
// aaaaa:50XcgR31jl/4M
// from problem set docs:
// Z = 50R.6FuTGui8U
// https://cs50.stackexchange.com/questions/24856/pset2-crack-vs-pointers
// anushree:50xcIMJ0y.RXo = YES
// brian:50mjprEcqC/ts = CA
// bjbrown:50GApilQSG3E2 = UPenn (takes a while)
// lloyd:50n0AAUD.pL8g = lloyd (takes a while)
// malan:50CcfIk1QrPr6 = maybe (takes a while)
// maria:509nVI8B9VfuA = TF
// natmelo:50JIIyhDORqMU = nope
// rob:50JGnXUgaafgc = ROFL
// stelios:51u8F0dkeDSbY = NO
// zamyla:50cI2vYkF0YU2 = LOL

int main(int argc, char *argv[])  // declaring char *argv[] here is telling the function to expect a char type input & a its gonna be a pointer to an array of characters (remember how these work?)
{
    if (argc != 2)  // prevent the user from not entering the correct number of command line arguments
    {
        printf("Invalid Hash Needed!:\n ");
        return 1;
    }
    char *user_input;      // declare a pointer (it's own variable in memory) called user_input
    user_input = argv[1];  // pointing to the array of characters, that the user inputted in each index of memory from arg[1]

    char salt[3] = {user_input[0], user_input[1], '\0'};  // declare an array of size 3. To store each of the two characters of the salt. The user input at the [0]th index of user_input & [1]st index of user_input + the null character at the end
    string alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";  // declare an array of ALL OF THE test letters in the alphabet (a string is also an array of chars remember)
    char guess[5];  // declare an array of size FIVE that will store our guesses spat out (X to XXXX)

    for (int i = 0; i < strlen(alphabet); i++)  // check your onenote for how these forloops work. This loops through 1 char (a-Z)
    {
        guess[0] = alphabet[i];
        guess[1] = '\0';

        if (strcmp(crypt(guess, salt), argv[1]) == 0)  // check to compare the plaintext guess + salt & the hash in argv[1] with the strcmp() function AFTER it's encrypted into a hash with the crypt() function
        {
            printf("Password: %s\n", guess);  // print the guess on the last iteration of the loop if the above condition is true
            return 0; // program is kill if the loop if above was successful
        }
    }

    for (int i = 0; i < strlen(alphabet); i++)  // check onenote for how these nested forloops work. This loops through 2 chars (a-ZZ)
    {
        guess[0] = alphabet[i];
        for (int j = 0; j < strlen(alphabet); j++)
        {
            guess[1] = alphabet[j];
            guess[2] = '\0';

            if (strcmp(crypt(guess, salt), argv[1]) == 0)  // check to compare the plaintext guess + salt & the hash in argv[1] with the strcmp() function AFTER it's encrypted into a hash with the crypt() function
            {
                printf("Password: %s\n", guess);  // print the guess on the last iteration of the loop if the above condition is true
                return 0; // program is kill if the loop if above was successful
            }
        }
    }

    for (int i = 0; i < strlen(alphabet); i++)  // check onenote for how thes enested forloops work. This loops through 3 chars (a-ZZZ)
    {
        guess[0] = alphabet[i];
        for (int j = 0; j < strlen(alphabet); j++)
        {
            guess[1] = alphabet[j];
            for (int k = 0; k < strlen(alphabet); k++)
            {
                guess[2] = alphabet[k];
                guess[3] = '\0';

                if (strcmp(crypt(guess, salt), argv[1]) == 0)  // check to compare the plaintext guess + salt & the hash in argv[1] with the strcmp() function AFTER it's encrypted into a hash with the crypt() function
                {
                    printf("Password: %s\n", guess);  // print the guess on the last iteration of the loop if the above condition is true
                    return 0; // program is kill if the loop if above was successful
                }
            }
        }
    }

    for (int i = 0; i < strlen(alphabet); i++)  // check onenote for how these nested forloops work. This loops through 4 chars (a-ZZZZ)
    {
        guess[0] = alphabet[i];
        for (int j = 0; j < strlen(alphabet); j++)
        {
            guess[1] = alphabet[j];
            for (int k = 0; k < strlen(alphabet); k++)
            {
                guess[2] = alphabet[k];
                for (int l = 0; l < strlen(alphabet); l++)
                {
                    guess[3] = alphabet[l];
                    guess[4] = '\0';

                    if (strcmp(crypt(guess, salt), argv[1]) == 0)  // check to compare the plaintext guess + salt & the hash in argv[1] with the strcmp() function AFTER it's encrypted into a hash with the crypt() function
                    {
                        printf("Password: %s\n", guess);  // print the guess on the last iteration of the loop if the above condition is true
                        return 0; // program is kill if the loop if above was successful
                    }
                }
            }
        }
    }
    printf("\n");
}