3 * $Id: field.h,v 1.2 2001/05/07 17:30:13 mdw Exp $
5 * Definitions for field arithmetic
7 * (c) 2000 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 2001/05/07 17:30:13 mdw
34 * Add an internal-representation no-op function.
36 * Revision 1.1 2001/04/29 18:12:33 mdw
41 #ifndef CATACOMB_FIELD_H
42 #define CATACOMB_FIELD_H
48 /*----- Header files ------------------------------------------------------*/
54 /*----- Data structures ---------------------------------------------------*/
56 typedef struct field
{
57 const struct field_ops
*ops
; /* Field operations */
58 mp
*zero
, *one
; /* Identities in the field */
61 typedef struct field_ops
{
63 /* --- Universal operations --- */
65 void (*destroy
)(field */
*f*/
);
67 mp
*(*in
)(field */
*f*/
, mp */
*d*/
, mp */
*x*/
);
68 mp
*(*out
)(field */
*f*/
, mp */
*d*/
, mp */
*x*/
);
70 mp
*(*add
)(field */
*f*/
, mp */
*d*/
, mp */
*x*/
, mp */
*y*/
);
71 mp
*(*sub
)(field */
*f*/
, mp */
*d*/
, mp */
*x*/
, mp */
*y*/
);
72 mp
*(*mul
)(field */
*f*/
, mp */
*d*/
, mp */
*x*/
, mp */
*y*/
);
73 mp
*(*sqr
)(field */
*f*/
, mp */
*d*/
, mp */
*x*/
);
74 mp
*(*inv
)(field */
*f*/
, mp */
*d*/
, mp */
*x*/
);
75 mp
*(*reduce
)(field */
*f*/
, mp */
*d*/
, mp */
*x*/
);
77 /* --- Operations for prime fields only --- */
79 mp
*(*dbl
)(field */
*f*/
, mp */
*d*/
, mp */
*x*/
);
80 mp
*(*tpl
)(field */
*f*/
, mp */
*d*/
, mp */
*x*/
);
81 mp
*(*sqrt
)(field */
*f*/
, mp */
*d*/
, mp */
*x*/
);
85 #define F_DESTROY(f) (f)->ops->destroy((f))
87 #define F_IN(f, d, x) (f)->ops->in((f), (d), (x))
88 #define F_OUT(f, d, x) (f)->ops->out((f), (d), (x))
89 #define F_ADD(f, d, x, y) (f)->ops->add((f), (d), (x), (y))
90 #define F_SUB(f, d, x, y) (f)->ops->sub((f), (d), (x), (y))
91 #define F_MUL(f, d, x, y) (f)->ops->mul((f), (d), (x), (y))
92 #define F_SQR(f, d, x) (f)->ops->sqr((f), (d), (x))
93 #define F_INV(f, d, x) (f)->ops->inv((f), (d), (x))
94 #define F_REDUCE(f, d, x) (f)->ops->reduce((f), (d), (x))
96 #define F_DBL(f, d, x) (f)->ops->dbl((f), (d), (x))
97 #define F_TPL(f, d, x) (f)->ops->tpl((f), (d), (x))
98 #define F_SQRT(f, d, x) (f)->ops->sqrt((f), (d), (x))
100 /*----- Helpful field operations ------------------------------------------*/
102 /* --- @field_id@ --- *
104 * Arguments: @field *f@ = pointer to a field
105 * @mp *d@ = a destination element
106 * @mp *x@ = a source element
108 * Returns: The result element.
110 * Use: An identity operation which can be used if your field has no
111 * internal representation.
114 extern mp
*field_id(field */
*f*/
, mp */
*d*/
, mp */
*x*/
);
116 /*----- Creating fields ---------------------------------------------------*/
118 /* --- @field_prime@ --- *
120 * Arguments: @mp *p@ = the characteristic of the field
122 * Returns: A pointer to the field.
124 * Use: Creates a field structure for a prime field of size %$p$%,
125 * using Montgomery reduction for arithmetic.
128 extern field
*field_prime(mp */
*p*/
);
130 /* --- @field_binpoly@ --- *
132 * Arguments: @mp *p@ = an irreducible polynomial over %$\gf{2}$%
134 * Returns: A pointer to the field.
136 * Use: Creates a field structure for a binary field using naive
140 extern field
*field_binpoly(mp */
*p*/
);
142 /* --- @field_binsparsepoly@ --- *
144 * Arguments: @unsigned deg@ = the degree of the field polynomial
145 * @const unsigned *c@ = degrees of nonzero coefficients
147 * Returns: A pointer to the field.
149 * Use: Creates a field structure for a binary field taking advantage
150 * of the sparseness of the given polynomial to improve
151 * reduction performance.
154 extern field
*field_binsparsepoly(unsigned /*deg*/, const unsigned */
*c*/
);
156 /*----- That's all, folks -------------------------------------------------*/