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   1 /* -*-c-*-
   2  *
   3  * $Id: pfilt.h,v 1.1 1999/12/22 15:49:39 mdw Exp $
   4  *
   5  * Finding and testing prime numbers
   6  *
   7  * (c) 1999 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: pfilt.h,v $
  33  * Revision 1.1  1999/12/22 15:49:39  mdw
  34  * Renamed from `pgen'.  Reworking for new prime-search system.
  35  *
  36  * Revision 1.3  1999/12/10 23:29:48  mdw
  37  * Change header file guard names.
  38  *
  39  * Revision 1.2  1999/11/20 22:23:05  mdw
  40  * Add multiply-and-add function for Diffie-Hellman safe prime generation.
  41  *
  42  * Revision 1.1  1999/11/19 13:17:57  mdw
  43  * Prime number generator and tester.
  44  *
  45  */
  46
  47 #ifndef CATACOMB_PFILT_H
  48 #define CATACOMB_PFILT_H
  49
  50 #ifdef __cplusplus
  51   extern "C" {
  52 #endif
  53
  54 /*----- Header files ------------------------------------------------------*/
  55
  56 #ifndef CATACOMB_MP_H
  57 #  include "mp.h"
  58 #endif
  59
  60 #ifndef CATACOMB_PTAB_H
  61 #  include "primetab.h"
  62 #endif
  63
  64 /*----- Data structures ---------------------------------------------------*/
  65
  66 typedef struct pfilt {
  67   mp *m;
  68   unsigned char r[NPRIME];
  69 } pfilt;
  70
  71 /*----- Functions provided ------------------------------------------------*/
  72
  73 /* --- @pfilt_create@ --- *
  74  *
  75  * Arguments:   @pfilt *p@ = pointer to prime filtering context
  76  *              @mp *m@ = pointer to initial number to test
  77  *
  78  * Returns:     A @PGEN@ result code.
  79  *
  80  * Use:         Tests an initial number for primality by computing its
  81  *              residue modulo various small prime numbers.  This is fairly
  82  *              quick, but not particularly certain.  If a @PGEN_TRY@
  83  *              result is returned, perform Rabin-Miller tests to confirm.
  84  */
  85
  86 extern int pfilt_create(pfilt */*p*/, mp */*m*/);
  87
  88 /* --- @pfilt_destroy@ --- *
  89  *
  90  * Arguments:   @pfilt *p@ = pointer to prime filtering context
  91  *
  92  * Returns:     ---
  93  *
  94  * Use:         Discards a context and all the resources it holds.
  95  */
  96
  97 extern void pfilt_destroy(pfilt */*p*/);
  98
  99 /* --- @pfilt_step@ --- *
 100  *
 101  * Arguments:   @pfilt *p@ = pointer to prime filtering context
 102  *              @mpw step@ = how much to step the number
 103  *
 104  * Returns:     One of the @PGEN@ result codes.
 105  *
 106  * Use:         Steps a number by a small amount.  Stepping is much faster
 107  *              than initializing with a new number.  The test performed is
 108  *              the same simple one used by @primetab_create@, so @PGEN_TRY@
 109  *              results should be followed up by a Rabin-Miller test.
 110  */
 111
 112 extern int pfilt_step(pfilt */*p*/, mpw /*step*/);
 113
 114 /* --- @pfilt_muladd@ --- *
 115  *
 116  * Arguments:   @pfilt *p@ = destination prime filtering context
 117  *              @const pfilt *q@ = source prime filtering context
 118  *              @mpw m@ = number to multiply by
 119  *              @mpw a@ = number to add
 120  *
 121  * Returns:     One of the @PGEN@ result codes.
 122  *
 123  * Use:         Multiplies the number in a prime filtering context by a
 124  *              small value and then adds a small value.  The destination
 125  *              should either be uninitialized or the same as the source.
 126  *
 127  *              Common things to do include multiplying by 2 and adding 0 to
 128  *              turn a prime into a jump for finding other primes with @q@ as
 129  *              a factor of @p - 1@, or multiplying by 2 and adding 1.
 130  */
 131
 132 extern int pfilt_muladd(pfilt */*p*/, const pfilt */*q*/,
 133                         mpw /*m*/, mpw /*a*/);
 134
 135 /* --- @pfilt_jump@ --- *
 136  *
 137  * Arguments:   @pfilt *p@ = pointer to prime filtering context
 138  *              @const pfilt *j@ = pointer to another filtering context
 139  *
 140  * Returns:     One of the @PGEN@ result codes.
 141  *
 142  * Use:         Steps a number by a large amount.  Even so, jumping is much
 143  *              faster than initializing a new number.  The test peformed is
 144  *              the same simple one used by @primetab_create@, so @PGEN_TRY@
 145  *              results should be followed up by a Rabin-Miller test.
 146  *
 147  *              Note that the number stored in the @j@ context is probably
 148  *              better off being even than prime.  The important thing is
 149  *              that all of the residues for the number have already been
 150  *              computed.
 151  */
 152
 153 extern int pfilt_jump(pfilt */*p*/, const pfilt */*j*/);
 154
 155 /*----- That's all, folks -------------------------------------------------*/
 156
 157 #ifdef __cplusplus
 158   }
 159 #endif
 160
 161 #endif