/*
 * Copyright (c) 2005-2008 robert wilson
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#define _GNU_SOURCE

#include <ctype.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <time.h>
#include <unistd.h>
#include <openssl/des.h>

#ifndef HEADER_NEW_DES_H
#define DES_fcrypt des_fcrypt
#endif

#ifdef __predict_false
#define probably_false(x) __predict_false(x)
#else
#define probably_false(x) (x)
#endif

#ifdef NO_STRCASESTR
char *strcasestr(const char *a, const char *b){
 size_t l;
 char f[3];
 snprintf(f, sizeof(f), "%c%c", tolower(*b), toupper(*b));
 for(l = strcspn(a, f); l != strlen(a); l += strcspn(a + l + 1, f) + 1)
  if(strncasecmp(a + l, b, strlen(b)) == 0) return (char *)(a + l);
 return NULL;
}
#endif

uint_fast32_t z1, z2, z3, z4;

static inline uint32_t lfsr113(){
 z1 = ((z1 & 4294967294) << 18) ^ ((((z1 << 6) ^ z1) & UINT32_MAX) >> 13);
 z2 = ((z2 & 4294967288) << 2) ^ ((((z2 << 2) ^ z2) & UINT32_MAX) >> 27);
 z3 = ((z3 & 4294967280) << 7) ^ ((((z3 << 13) ^ z3) & UINT32_MAX) >> 21);
 z4 = ((z4 & 4294967168) << 13) ^ ((((z4 << 3) ^ z4) & UINT32_MAX) >> 12);
 return z1 ^ z2 ^ z3 ^ z4;
}

static inline void init_lfsr113(long seed){
 srand48(seed);
 z1 = lrand48();
 z2 = lrand48();
 z3 = lrand48();
 z4 = lrand48();
 for(int i = 0; i < 256; ++i) lfsr113();
}

int main(int argc, char *argv[]){
 const char tripc[] = " !#$%()*+-./0123456789:;=?ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]"
  "^_`abcdefghijklmnopqrstuvwxyz{|}~&";
 const char saltc[] = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqr"
  "stuvwxyz";
 char salt[2] = {0}, cap[24] = {0};
 char *searchstring, *temp = cap + 10, *trip = temp + 3;
 char *(*compare)(const char *, const char *);
 int c;
 uint_fast8_t i, cflag = 0;
 while((c = getopt(argc, argv, "c")) != -1)
  switch(c){
   case 'c':
    cflag = 1;
    break;
   case '?':
    printf("Usage: %s [-c] [regex]\n", argv[0]);
    return 1;
   default:
    abort();
  }
 if(optind < argc) searchstring = argv[optind];
 else{
  searchstring = "";
  cflag = 1;
 }
 init_lfsr113(time(0));
 compare = cflag ? &strstr : &strcasestr;
 cap[8] = cap[9] = ' ';
 for(;;){
  cap[0] = tripc[lfsr113() % (sizeof(tripc) - 2)];
  salt[0] = saltc[lfsr113() % (sizeof(saltc) - 1)];
  salt[1] = saltc[lfsr113() % (sizeof(saltc) - 1)];
  memcpy(cap + 1, salt, 2);
  for(i = 3; i < 7; ++i) cap[i] = tripc[lfsr113() % (sizeof(tripc) - 2)];
  cap[7] = tripc[lfsr113() % (sizeof(tripc) - 1)];
  DES_fcrypt(cap, salt, temp);
  if(probably_false(compare(trip, searchstring))){
   cap[10] = '=';
   cap[11] = cap[12] = ' ';
   cap[23] = '\n';
   fwrite(cap, 24, 1, stdout);
  }
 }
 return(0);
}