bruteforce.c

#include "bruteforce.h"

void getGuess()
{
    // TODO: letter frequency analysis
    const char chars[CHAR_COUNT+1] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1203495687.!-@*_$#/,+%&?;=~^)[\\]`(:<'>|\"";
    int i, j;
    int guessc[MAX_SIZE] = {0};     // counter
    char guess[MAX_SIZE+1];         // chars crresponding to counter

    for(i = 1; i < MAX_SIZE ; guessc[i++] = -1);        // initializing counter with -1
    for(i = 1; i <= MAX_SIZE ; guess[i++] = '\0');      // initializing guess with NULL
    // change the initialisation of guess if you want the algorithm to start with a certain word/length.

    // if you want to constrain the algorithm to a certain length of password you could add a new var k, such that k < CHAR_COUNT^max_password_length
    // you could use the following code:
    // add #include <math.h> to the header file
    // and the following to the cpp file:
    //  int k = 0;
    //  while(k++ < pow(CHAR_COUNT,MAX_PASSWORD_LENGTH))
    // you would have to define MAX_PASSWORD_LENGTH as the max length passwords you want to try

    while(1)    // change here if you want to configure the max number of guesses
    {
        // increment guessc[i+1] if guessc[i] is bigger than the number of chars in the array
        i=0;
        while(guessc[i]==CHAR_COUNT)    // check all counter elements wether theire value is bigger than the number of chars stored in CHAR_COUNT or not
        {
            guessc[i]=0;                // reset the element that is bigger than CHAR_COUNT to 0
            guessc[++i]+=1;             // increment the next element (index i+1)
        }

        for(j=0;j<=i;++j)   // change all chars that differ from the last guess (the number of chars changed is equal to the number of counter elements tested(=i))
        {
            // you could remove this if statement since it is infeasibly to bruteforce a 30 char long password in a reasonable amount of time
            // if you want the algorithm to stop after a certain length you should change the while loop at line 23 not MAX_SIZE
            // MAX_SIZE is only used to avoid accessing an index bigger than the array size!
            if(j < MAX_SIZE) // check if an element guess[j] exists
                guess[j]=chars[guessc[j]];
        }
        // output the guess to std::out
        printf("%s\n",guess);   // printf is used since it is way faster than std::cout

        ++guessc[0];    // increment guessc at index 0 for the next run
    }
}