exploit-omp.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <omp.h>
#include <math.h>

#define PASSWORD_LEN 8

int found = 0;
int num_threads = 1;
int total_tries = 0;

int main(int argc, char *argv[])
{
    if (argc > 1)
    {
        num_threads = atoi(argv[1]);
    }

    struct timeval start_time, end_time;

    gettimeofday(&start_time, NULL);

    // Set the number of threads
    omp_set_num_threads(num_threads);

    // The total number of possible passwords
    int total = pow(10, PASSWORD_LEN);

// Parallelize the password cracking with OpenMP
#pragma omp parallel for shared(found) reduction(+ : total_tries)
    for (int i = 0; i < total; i++)
    {
        if (found)
        {
            continue;
        }

        char password[7];
        sprintf(password, "%05d", i);

        pid_t pid = fork();

        if (pid == -1)
        {
            perror("fork");
            continue;
        }
        else if (pid == 0)
        {
            char *args[] = {"./prog", password, NULL};
            execv(args[0], args);

            perror("execv");
            exit(1);
        }
        else
        {
            int status;
            waitpid(pid, &status, 0);

            if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
            {
#pragma omp critical
                {
                    if (!found)
                    {
                        printf("Password found: %s\n", password);
                        found = 1;
                    }
                }
            }
        }

        total_tries++;
    }

    gettimeofday(&end_time, NULL);

    if (!found)
    {
        printf("Password not found.\n");
    }

    double elapsed_time = (end_time.tv_sec - start_time.tv_sec) + (end_time.tv_usec - start_time.tv_usec) / 1e6;
    double tries_per_second = total_tries / elapsed_time;

    printf("Time taken: %.6f seconds\n", elapsed_time);
    printf("Estimated tries per second: %.6f\n", tries_per_second);

    return 0;
}