pset2 crack.c not working on 5 digits codes but working on all others

Question

i'm brand new here also bit dyslexic my spelling can be rough in comments so bee gentle pls:)

basically I've made a code for crack.c which cracks 1-4digit passwords but does not work with 5 digit passwords i think I've declared the array correctly to have space for the null ect.

when running though in debug mode starting it at char pass[6] = { 'A' , 'A' , 'A' , 'A' , 'A' , '\0' }; // too make sure i don't need 2 go thought all the 1-4digit passwords

the hash I'm looking for CAAAA when hashed is different than when i hash it using crypt with the same salt of course. (i checked with the output hash from crack.c and did it find CAAAA)

I also checked if the hash matched AAAA or CAAA incase it was chopping off a letter cause of some part of C i don't understand yet.

another side note atm my code is way away from being optimised that was what i was planning to work on next and wanna try figure out for myself:)

anyway heres the code in question:

#include <stdio.h>
#include <cs50.h>
#include <math.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#define _XOPEN_SOURCE
#include <unistd.h>
#include <crypt.h>


int main(int argc , string argv[]){

if (argc != 2){     //checks for valid commend line input
    printf("Invalid");
    return 1;
} else {




int passSize = 6; // sets password max length to check
char pass[6] = { 0 , 0 , 0 , 0 , 0 , 0 };//makes array 4 brute 

string cryptPass;
int digit = 0;
string hashPass = argv[1];

char salt[3];

strncpy(salt, hashPass, 2);  //copys first to digits of hashed password salt


printf("%s\n", salt);



while (passSize >= digit){  //loop to go over every combo of alphabet 

 digit = 0;
while (digit < passSize){

    if (pass[digit] == 0){
    pass[digit] = 'A';

    break;
    }
        if (pass[digit] >= 'A' && pass[digit] <'z'){
        pass[digit]++;

        break;
        }
            if (pass[digit] == 'z') {
            pass[digit] = 'A';
            digit++;
            }


                if (digit >= passSize){ // checks if all combos hav bin done

                    printf("no PassWord found\n");
                    return 0;
                    break;
                }



}
printf("password: '%s'\n", pass); // used for debugging
//printf("password: '%s'\n", salt);
cryptPass = crypt(pass, salt); //creates a variable with a hashed try
if (strcmp(hashPass , cryptPass) == 0) { //compares hashed try too hash
printf("password Found: %s\n" , pass); // if they are match returns pword

return 0;
break;
//printf("%s\n", crypt(pass, "50"));
}printf("%s\n", cryptPass);
printf("%s\n", hashPass);


}
}
}

any help / insight appreciated!

Answer 1

First, please fix your indentation. It's hard to see what belongs to which code block.

Is int passSize = 6 intentional? Shouldn't it be 5?

Your code never sets salt[2] to '\0'. But I guess crypt won't look at the third character anyway, as the salt is two characters by definition. Your printf does care. Maybe you're lucky and the next byte is zero by coincidence.

Note that pass[digit] >= 'A' && pass[digit] <'z' includes 6 characters that are not alphabetic. Might make your code slightly less efficient.