3 * $Id: pfilt.h,v 1.3 2004/04/01 12:50:09 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 1.3 2004/04/01 12:50:09 mdw
34 * Add cyclic group abstraction, with test code. Separate off exponentation
35 * functions for better static linking. Fix a buttload of bugs on the way.
36 * Generally ensure that negative exponents do inversion correctly. Add
37 * table of standard prime-field subgroups. (Binary field subgroups are
38 * currently unimplemented but easy to add if anyone ever finds a good one.)
40 * Revision 1.2 2000/08/15 21:42:56 mdw
41 * Use the small primes type from `genprimes' output. New function for
42 * doing trial division the hard way.
44 * Revision 1.1 1999/12/22 15:49:39 mdw
45 * Renamed from `pgen'. Reworking for new prime-search system.
47 * Revision 1.3 1999/12/10 23:29:48 mdw
48 * Change header file guard names.
50 * Revision 1.2 1999/11/20 22:23:05 mdw
51 * Add multiply-and-add function for Diffie-Hellman safe prime generation.
53 * Revision 1.1 1999/11/19 13:17:57 mdw
54 * Prime number generator and tester.
58 #ifndef CATACOMB_PFILT_H
59 #define CATACOMB_PFILT_H
65 /*----- Header files ------------------------------------------------------*/
71 #ifndef CATACOMB_PRIMETAB_H
72 # include "primetab.h"
75 /*----- Data structures ---------------------------------------------------*/
77 typedef struct pfilt
{
82 /*----- Functions provided ------------------------------------------------*/
84 /* --- @pfilt_smallfactor@ --- *
86 * Arguments: @mp *m@ = integer to test
88 * Returns: One of the @PGEN@ result codes.
90 * Use: Tests a number by dividing by a number of small primes. This
91 * is a useful first step if you're testing random primes; for
92 * sequential searches, @pfilt_create@ works better.
95 extern int pfilt_smallfactor(mp */
*m*/
);
97 /* --- @pfilt_create@ --- *
99 * Arguments: @pfilt *p@ = pointer to prime filtering context
100 * @mp *m@ = pointer to initial number to test
102 * Returns: A @PGEN@ result code.
104 * Use: Tests an initial number for primality by computing its
105 * residue modulo various small prime numbers. This is fairly
106 * quick, but not particularly certain. If a @PGEN_TRY@
107 * result is returned, perform Rabin-Miller tests to confirm.
110 extern int pfilt_create(pfilt */
*p*/
, mp */
*m*/
);
112 /* --- @pfilt_destroy@ --- *
114 * Arguments: @pfilt *p@ = pointer to prime filtering context
118 * Use: Discards a context and all the resources it holds.
121 extern void pfilt_destroy(pfilt */
*p*/
);
123 /* --- @pfilt_step@ --- *
125 * Arguments: @pfilt *p@ = pointer to prime filtering context
126 * @mpw step@ = how much to step the number
128 * Returns: One of the @PGEN@ result codes.
130 * Use: Steps a number by a small amount. Stepping is much faster
131 * than initializing with a new number. The test performed is
132 * the same simple one used by @primetab_create@, so @PGEN_TRY@
133 * results should be followed up by a Rabin-Miller test.
136 extern int pfilt_step(pfilt */
*p*/
, mpw
/*step*/);
138 /* --- @pfilt_muladd@ --- *
140 * Arguments: @pfilt *p@ = destination prime filtering context
141 * @const pfilt *q@ = source prime filtering context
142 * @mpw m@ = number to multiply by
143 * @mpw a@ = number to add
145 * Returns: One of the @PGEN@ result codes.
147 * Use: Multiplies the number in a prime filtering context by a
148 * small value and then adds a small value. The destination
149 * should either be uninitialized or the same as the source.
151 * Common things to do include multiplying by 2 and adding 0 to
152 * turn a prime into a jump for finding other primes with @q@ as
153 * a factor of @p - 1@, or multiplying by 2 and adding 1.
156 extern int pfilt_muladd(pfilt */
*p*/
, const pfilt */
*q*/
,
157 mpw
/*m*/, mpw
/*a*/);
159 /* --- @pfilt_jump@ --- *
161 * Arguments: @pfilt *p@ = pointer to prime filtering context
162 * @const pfilt *j@ = pointer to another filtering context
164 * Returns: One of the @PGEN@ result codes.
166 * Use: Steps a number by a large amount. Even so, jumping is much
167 * faster than initializing a new number. The test peformed is
168 * the same simple one used by @primetab_create@, so @PGEN_TRY@
169 * results should be followed up by a Rabin-Miller test.
171 * Note that the number stored in the @j@ context is probably
172 * better off being even than prime. The important thing is
173 * that all of the residues for the number have already been
177 extern int pfilt_jump(pfilt */
*p*/
, const pfilt */
*j*/
);
179 /*----- That's all, folks -------------------------------------------------*/