// PROGRAM TO CRACK PASSWORD MADE FROM C's DES bases crypt function

//importing libraries
#define _XOPEN_SOURCE
#include <unistd.h>
#include <stdio.h>
#include <cs50.h>
#include <ctype.h>
#include <string.h>


int main(int argc, string argv[])
{
    if (argc != 2)              //to check if only two arguments are given
    {
        printf("Give only two arguments, the filename and hashed password.\n");
        return 1;
    }

    char key[] = {argv[1][0], argv[1][1]};          //to etract key from hashed password

    char pass[6];                                   //making a temporary array to hold 5 characters
    string testpass;                                //string to hold testing password

    while (true)
    {
        for (pass[0] = 'A'; pass[0] <= 'z'; pass[0]++)      //condition to crack one lettered password
        {
            if (isalpha(pass[0]))
            {
                pass[1] = '\0';
                testpass = pass;
                if (strcmp(crypt(testpass, key), argv[1]) == 0)
                {
                    printf("%s\n", testpass);
                    return 0;
                    break;
                }
            }
        }

        for (pass[0] = 'A'; pass[0] <= 'z'; pass[0]++)      //condition to crack two lettered password
        {
            if(isalpha(pass[0]))
            {
                for (pass[1] = 'A'; pass[1] <= 'z'; pass[1]++)
                {
                    if (isalpha(pass[1]))
                    {
                        pass[2] = '\0';
                        testpass = pass;
                        if (strcmp(crypt(testpass, key), argv[1]) == 0)
                        {
                            printf("%s\n", testpass);
                            return 0;
                            break;
                        }
                    }
                }
            }
        }

        for (pass[0] = 'A'; pass[0] <= 'z'; pass[0]++)      //condition to crack three lettered password
        {
            if (isalpha(pass[0]))
            {
                for (pass[1] = 'A'; pass[1] <= 'z'; pass[1]++)
                {
                    if (isalpha(pass[1]))
                    {
                        for (pass[2] = 'A'; pass[2] <= 'z'; pass[2]++)
                        {
                            if (isalpha(pass[2]))
                            {
                                pass[3] = '\0';
                                testpass = pass;
                                if (strcmp(crypt(testpass, key), argv[1]) == 0)
                                {
                                    printf("%s\n", testpass);
                                    return 0;
                                    break;
                                }
                            }
                        }
                    }
                }
            }
        }

        for (pass[0] = 'A'; pass[0] <= 'z'; pass[0]++)      //condition to crack four lettered password
        {
            if (isalpha(pass[0]))
            {
                for (pass[1] = 'A'; pass[1] <= 'z'; pass[1]++)
                {
                    if (isalpha(pass[1]))
                    {
                        for (pass[2] = 'A'; pass[2] <= 'z'; pass[2]++)
                        {
                            if (isalpha(pass[2]))
                            {
                                for (pass[3] = 'A'; pass[3] <= 'z'; pass[3]++)
                                {
                                    if (isalpha(pass[3]))
                                    {
                                        pass[4] = '\0';
                                        testpass = pass;
                                        if (strcmp(crypt(testpass, key), argv[1]) == 0)
                                        {
                                            printf("%s\n", testpass);
                                            return 0;
                                            break;
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }

        for (pass[0] = 'A'; pass[0] <= 'z'; pass[0]++)      //condition to crack five lettered password
        {
            if (isalpha(pass[0]))
            {
                for (pass[1] = 'A'; pass[1] <= 'z'; pass[1]++)
                {
                    if (isalpha(pass[1]))
                    {
                        for (pass[2] = 'A'; pass[2] <= 'z'; pass[2]++)
                        {
                            if (isalpha(pass[2]))
                            {
                                for (pass[3] = 'A'; pass[3] <= 'z'; pass[3]++)
                                {
                                    if (isalpha(pass[3]))
                                    {
                                        for (pass[4] = 'A'; pass[4] <= 'z'; pass[4]++)
                                        {
                                            if (isalpha(pass[4]))
                                            {
                                                pass[5] = '\0';
                                                testpass = pass;
                                                if (strcmp(crypt(testpass, key), argv[1]) == 0)
                                                {
                                                    printf("%s\n", testpass);
                                                    return 0;
                                                    break;
                                                }
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}