tripcode.c

#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <string.h>
#include <regex.h>
#include <crypt.h>   // -lcrypt
#include <pthread.h> // -lpthread

const char* chars = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
size_t chars_len;

void* thread(void* arg) {
   char pass[15], salt[3], trip[11];
   size_t pass_len;
   salt[2]  = 0;
   trip[10] = 0;
   int i;
   while(1) {
      pass_len = 5 + rand() % 8; // 5..10
      for(i = 0; i < pass_len; i++)
         pass[i] = chars[rand() % chars_len];
      pass[pass_len] = 0;
      strncpy(salt, &pass[1], 2);
      strncpy(trip, &(crypt(pass, salt))[3], 10);
      if(regexec((regex_t*)arg, trip, 0, NULL, 0) == 0)
         printf("!%s=%s\n", trip, pass);
   }
}

int main(int argc, char* argv[]) {
   if(argc < 2 || argc > 3) {
      printf("Usage: %s [regex] {threads}\n", argv[0]);
      return 0;
   }
   char* find = argv[1];
   chars_len = strlen(chars);
   srand(time(NULL));
   regex_t regex;
   assert(regcomp(&regex, find, REG_EXTENDED | REG_ICASE) == 0);
   if(argc > 2) {
      int num_threads = atoi(argv[2]);
      assert(num_threads > 0 && num_threads <= 20);
      pthread_t threads[num_threads];
      int i;
      for(i = 0; i < num_threads; i++)
         pthread_create(&threads[i], NULL, thread, (void*)&regex);
      for(i = 0; i < num_threads; i++)
         pthread_detach(threads[i]);
   }
   thread((void*)&regex);
   regfree(&regex);
   return 0;
}