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/security/nss/lib/freebl/mpi/utils/isprime.c

http://github.com/zpao/v8monkey
C | 121 lines | 58 code | 18 blank | 45 comment | 15 complexity | eb9144af3438a676b38eb43102e1b790 MD5 | raw file
  1/*
  2 *  isprime.c
  3 *
  4 *  Probabilistic primality tester command-line tool
  5 *
  6 * ***** BEGIN LICENSE BLOCK *****
  7 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  8 *
  9 * The contents of this file are subject to the Mozilla Public License Version
 10 * 1.1 (the "License"); you may not use this file except in compliance with
 11 * the License. You may obtain a copy of the License at
 12 * http://www.mozilla.org/MPL/
 13 *
 14 * Software distributed under the License is distributed on an "AS IS" basis,
 15 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 16 * for the specific language governing rights and limitations under the
 17 * License.
 18 *
 19 * The Original Code is the MPI Arbitrary Precision Integer Arithmetic library.
 20 *
 21 * The Initial Developer of the Original Code is
 22 * Michael J. Fromberger.
 23 * Portions created by the Initial Developer are Copyright (C) 1998
 24 * the Initial Developer. All Rights Reserved.
 25 *
 26 * Contributor(s):
 27 *
 28 * Alternatively, the contents of this file may be used under the terms of
 29 * either the GNU General Public License Version 2 or later (the "GPL"), or
 30 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 31 * in which case the provisions of the GPL or the LGPL are applicable instead
 32 * of those above. If you wish to allow use of your version of this file only
 33 * under the terms of either the GPL or the LGPL, and not to allow others to
 34 * use your version of this file under the terms of the MPL, indicate your
 35 * decision by deleting the provisions above and replace them with the notice
 36 * and other provisions required by the GPL or the LGPL. If you do not delete
 37 * the provisions above, a recipient may use your version of this file under
 38 * the terms of any one of the MPL, the GPL or the LGPL.
 39 *
 40 * ***** END LICENSE BLOCK ***** */
 41/* $Id: isprime.c,v 1.3 2004/04/27 23:04:37 gerv%gerv.net Exp $ */
 42
 43#include <stdio.h>
 44#include <stdlib.h>
 45#include <string.h>
 46
 47#include "mpi.h"
 48#include "mpprime.h"
 49
 50#define  RM_TESTS       15   /* how many iterations of Rabin-Miller? */
 51#define  MINIMUM        1024 /* don't bother us with a < this        */
 52
 53int      g_tests = RM_TESTS;
 54char    *g_prog = NULL;
 55
 56int main(int argc, char *argv[])
 57{
 58  mp_int   a;
 59  mp_digit np = prime_tab_size; /* from mpprime.h */
 60  int      res = 0;
 61
 62  g_prog = argv[0];
 63
 64  if(argc < 2) {
 65    fprintf(stderr, "Usage: %s <a>, where <a> is a decimal integer\n"
 66	    "Use '0x' prefix for a hexadecimal value\n", g_prog);
 67    return 1;
 68  }
 69
 70  /* Read number of tests from environment, if present */
 71  {
 72    char *tmp;
 73
 74    if((tmp = getenv("RM_TESTS")) != NULL) {
 75      if((g_tests = atoi(tmp)) <= 0)
 76	g_tests = RM_TESTS;
 77    }
 78  }
 79
 80  mp_init(&a);
 81  if(argv[1][0] == '0' && argv[1][1] == 'x')
 82    mp_read_radix(&a, argv[1] + 2, 16);
 83  else
 84    mp_read_radix(&a, argv[1], 10);
 85
 86  if(mp_cmp_d(&a, MINIMUM) <= 0) {
 87    fprintf(stderr, "%s: please use a value greater than %d\n", 
 88	    g_prog, MINIMUM);
 89    mp_clear(&a);
 90    return 1;
 91  }
 92
 93  /* Test for divisibility by small primes */
 94  if(mpp_divis_primes(&a, &np) != MP_NO) {
 95    printf("Not prime (divisible by small prime %d)\n", np);
 96    res = 2;
 97    goto CLEANUP;
 98  }
 99
100  /* Test with Fermat's test, using 2 as a witness */
101  if(mpp_fermat(&a, 2) != MP_YES) {
102    printf("Not prime (failed Fermat test)\n");
103    res = 2;
104    goto CLEANUP;
105  }
106 
107  /* Test with Rabin-Miller probabilistic test */
108  if(mpp_pprime(&a, g_tests) == MP_NO) {
109      printf("Not prime (failed pseudoprime test)\n");
110      res = 2;
111      goto CLEANUP;
112  }
113
114  printf("Probably prime, 1 in 4^%d chance of false positive\n", g_tests);
115
116CLEANUP:
117  mp_clear(&a);
118  
119  return res;
120
121}