3 * $Id: pfilt.h,v 1.2 2000/08/15 21:42:56 mdw Exp $
5 * Finding and testing prime numbers
7 * (c) 1999 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
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.
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.
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,
30 /*----- Revision history --------------------------------------------------*
33 * Revision 1.2 2000/08/15 21:42:56 mdw
34 * Use the small primes type from `genprimes' output. New function for
35 * doing trial division the hard way.
37 * Revision 1.1 1999/12/22 15:49:39 mdw
38 * Renamed from `pgen'. Reworking for new prime-search system.
40 * Revision 1.3 1999/12/10 23:29:48 mdw
41 * Change header file guard names.
43 * Revision 1.2 1999/11/20 22:23:05 mdw
44 * Add multiply-and-add function for Diffie-Hellman safe prime generation.
46 * Revision 1.1 1999/11/19 13:17:57 mdw
47 * Prime number generator and tester.
51 #ifndef CATACOMB_PFILT_H
52 #define CATACOMB_PFILT_H
58 /*----- Header files ------------------------------------------------------*/
64 #ifndef CATACOMB_PTAB_H
65 # include "primetab.h"
68 /*----- Data structures ---------------------------------------------------*/
70 typedef struct pfilt
{
75 /*----- Functions provided ------------------------------------------------*/
77 /* --- @pfilt_smallfactor@ --- *
79 * Arguments: @mp *m@ = integer to test
81 * Returns: One of the @PGEN@ result codes.
83 * Use: Tests a number by dividing by a number of small primes. This
84 * is a useful first step if you're testing random primes; for
85 * sequential searches, @pfilt_create@ works better.
88 extern int pfilt_smallfactor(mp */
*m*/
);
90 /* --- @pfilt_create@ --- *
92 * Arguments: @pfilt *p@ = pointer to prime filtering context
93 * @mp *m@ = pointer to initial number to test
95 * Returns: A @PGEN@ result code.
97 * Use: Tests an initial number for primality by computing its
98 * residue modulo various small prime numbers. This is fairly
99 * quick, but not particularly certain. If a @PGEN_TRY@
100 * result is returned, perform Rabin-Miller tests to confirm.
103 extern int pfilt_create(pfilt */
*p*/
, mp */
*m*/
);
105 /* --- @pfilt_destroy@ --- *
107 * Arguments: @pfilt *p@ = pointer to prime filtering context
111 * Use: Discards a context and all the resources it holds.
114 extern void pfilt_destroy(pfilt */
*p*/
);
116 /* --- @pfilt_step@ --- *
118 * Arguments: @pfilt *p@ = pointer to prime filtering context
119 * @mpw step@ = how much to step the number
121 * Returns: One of the @PGEN@ result codes.
123 * Use: Steps a number by a small amount. Stepping is much faster
124 * than initializing with a new number. The test performed is
125 * the same simple one used by @primetab_create@, so @PGEN_TRY@
126 * results should be followed up by a Rabin-Miller test.
129 extern int pfilt_step(pfilt */
*p*/
, mpw
/*step*/);
131 /* --- @pfilt_muladd@ --- *
133 * Arguments: @pfilt *p@ = destination prime filtering context
134 * @const pfilt *q@ = source prime filtering context
135 * @mpw m@ = number to multiply by
136 * @mpw a@ = number to add
138 * Returns: One of the @PGEN@ result codes.
140 * Use: Multiplies the number in a prime filtering context by a
141 * small value and then adds a small value. The destination
142 * should either be uninitialized or the same as the source.
144 * Common things to do include multiplying by 2 and adding 0 to
145 * turn a prime into a jump for finding other primes with @q@ as
146 * a factor of @p - 1@, or multiplying by 2 and adding 1.
149 extern int pfilt_muladd(pfilt */
*p*/
, const pfilt */
*q*/
,
150 mpw
/*m*/, mpw
/*a*/);
152 /* --- @pfilt_jump@ --- *
154 * Arguments: @pfilt *p@ = pointer to prime filtering context
155 * @const pfilt *j@ = pointer to another filtering context
157 * Returns: One of the @PGEN@ result codes.
159 * Use: Steps a number by a large amount. Even so, jumping is much
160 * faster than initializing a new number. The test peformed is
161 * the same simple one used by @primetab_create@, so @PGEN_TRY@
162 * results should be followed up by a Rabin-Miller test.
164 * Note that the number stored in the @j@ context is probably
165 * better off being even than prime. The important thing is
166 * that all of the residues for the number have already been
170 extern int pfilt_jump(pfilt */
*p*/
, const pfilt */
*j*/
);
172 /*----- That's all, folks -------------------------------------------------*/