3 * $Id: f-binpoly.c,v 1.1.2.1 2004/03/21 22:39:46 mdw Exp $
5 * Binary fields with polynomial basis representation
7 * (c) 2004 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 --------------------------------------------------*
32 * $Log: f-binpoly.c,v $
33 * Revision 1.1.2.1 2004/03/21 22:39:46 mdw
34 * Elliptic curves on binary fields work.
38 /*----- Header files ------------------------------------------------------*/
46 /*----- Data structures ---------------------------------------------------*/
53 /*----- Main code ---------------------------------------------------------*/
55 /* --- Field operations --- */
57 static void fdestroy(field *ff)
60 gfreduce_destroy(&f->r);
64 static int fzerop(field *ff, mp *x)
69 static mp *fadd(field *ff, mp *d, mp *x, mp *y)
71 return (gf_add(d, x, y));
74 static mp *fmul(field *ff, mp *d, mp *x, mp *y)
78 return (gfreduce_do(&f->r, d, d));
81 static mp *fsqr(field *ff, mp *d, mp *x)
85 return (gfreduce_do(&f->r, d, d));
88 static mp *finv(field *ff, mp *d, mp *x)
91 gf_gcd(0, 0, &d, f->r.p, x);
95 static mp *freduce(field *ff, mp *d, mp *x)
98 return (gfreduce_do(&f->r, d, x));
101 static mp *fsqrt(field *ff, mp *d, mp *x)
103 fctx *f = (fctx *)ff;
104 return (gfreduce_sqrt(&f->r, d, x));
107 static mp *fquadsolve(field *ff, mp *d, mp *x)
109 fctx *f = (fctx *)ff;
110 return (gfreduce_quadsolve(&f->r, d, x));
113 /* --- Field operations table --- */
115 static field_ops fops = {
118 fzerop, field_id, fadd, fadd, fmul, fsqr, finv, freduce, fsqrt,
123 /* --- @field_binpoly@ --- *
125 * Arguments: @mp *p@ = the reduction polynomial
127 * Returns: A pointer to the field.
129 * Use: Creates a field structure for a binary field mod @p@.
132 field *field_binpoly(mp *p)
134 fctx *f = CREATE(fctx);
138 gfreduce_create(&f->r, p);
142 /*----- That's all, folks -------------------------------------------------*/