git.distorted.org.uk Git - u/mdw/catacomb/blob - keycheck-mp.c

   1 /* -*-c-*-
   2  *
   3  * $Id: keycheck-mp.c,v 1.2 2004/04/08 01:36:15 mdw Exp $
   4  *
   5  * Key consistency checking tools for large integers
   6  *
   7  * (c) 2001 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Header files ------------------------------------------------------*/
  31
  32 #include <mLib/dstr.h>
  33
  34 #include "fibrand.h"
  35 #include "grand.h"
  36 #include "keycheck.h"
  37 #include "mp.h"
  38 #include "mprand.h"
  39 #include "pfilt.h"
  40 #include "pgen.h"
  41 #include "rabin.h"
  42 #include "rand.h"
  43
  44 /*----- Main code ---------------------------------------------------------*/
  45
  46 /* --- @keycheck_prime@ --- *
  47  *
  48  * Arguments:   @keycheck *kc@ = keycheck state
  49  *              @unsigned sev@ = severity if not prime
  50  *              @mp *m@ = a number to check for primality
  51  *              @const char *name@ = name of this number
  52  *
  53  * Returns:     Zero if OK, or return status from function.
  54  *
  55  * Use:         Checks that a number is prime.
  56  */
  57
  58 int keycheck_prime(keycheck *kc, unsigned sev, mp *m, const char *name)
  59 {
  60   int rc;
  61
  62   rc = pfilt_smallfactor(m);
  63   if (rc == PGEN_TRY) {
  64     rabin rn;
  65     grand *r = fibrand_create(0);
  66     unsigned n;
  67     mp *x = MP_NEW;
  68
  69     r->ops->misc(r, GRAND_SEEDRAND, &rand_global);
  70     n = rabin_iters(mp_bits(m));
  71     rabin_create(&rn, m);
  72     do {
  73       x = mprand_range(x, m, r, 0);
  74       rc = rabin_test(&rn, x);
  75       n--;
  76     } while (n && rc == PGEN_PASS);
  77     rabin_destroy(&rn);
  78     mp_drop(x);
  79     r->ops->destroy(r);
  80   }
  81   if (rc != PGEN_FAIL)
  82     rc = 0;
  83   else
  84     rc = keycheck_report(kc, sev, "%s not prime", name);
  85   return (rc);
  86 }
  87
  88 /*----- That's all, folks -------------------------------------------------*/