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

   1 /* -*-c-*-
   2  *
   3  * $Id: keycheck-mp.c,v 1.1 2001/02/03 16:08:24 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 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: keycheck-mp.c,v $
  33  * Revision 1.1  2001/02/03 16:08:24  mdw
  34  * Add consistency checking for public keys.
  35  *
  36  */
  37
  38 /*----- Header files ------------------------------------------------------*/
  39
  40 #include <mLib/dstr.h>
  41
  42 #include "fibrand.h"
  43 #include "grand.h"
  44 #include "keycheck.h"
  45 #include "mp.h"
  46 #include "mprand.h"
  47 #include "pfilt.h"
  48 #include "pgen.h"
  49 #include "rabin.h"
  50 #include "rand.h"
  51
  52 /*----- Main code ---------------------------------------------------------*/
  53
  54 /* --- @keycheck_prime@ --- *
  55  *
  56  * Arguments:   @keycheck *kc@ = keycheck state
  57  *              @unsigned sev@ = severity if not prime
  58  *              @mp *m@ = a number to check for primality
  59  *              @const char *name@ = name of this number
  60  *
  61  * Returns:     Zero if OK, or return status from function.
  62  *
  63  * Use:         Checks that a number is prime.
  64  */
  65
  66 int keycheck_prime(keycheck *kc, unsigned sev, mp *m, const char *name)
  67 {
  68   int rc;
  69
  70   rc = pfilt_smallfactor(m);
  71   if (rc == PGEN_TRY) {
  72     rabin rn;
  73     grand *r = fibrand_create(0);
  74     unsigned n;
  75     mp *x = MP_NEW;
  76
  77     r->ops->misc(r, GRAND_SEEDRAND, &rand_global);
  78     n = rabin_iters(mp_bits(m));
  79     rabin_create(&rn, m);
  80     do {
  81       x = mprand_range(x, m, r, 0);
  82       rc = rabin_test(&rn, x);
  83       n--;
  84     } while (n && rc == PGEN_PASS);
  85     rabin_destroy(&rn);
  86     mp_drop(x);
  87     r->ops->destroy(r);
  88   }
  89   if (rc != PGEN_FAIL)
  90     rc = 0;
  91   else
  92     rc = keycheck_report(kc, sev, "%s not prime", name);
  93   return (rc);
  94 }
  95
  96 /*----- That's all, folks -------------------------------------------------*/