ceb3f0c0 |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: f-binpoly.c,v 1.1.2.1 2004/03/21 22:39:46 mdw Exp $ |
4 | * |
5 | * Binary fields with polynomial basis representation |
6 | * |
7 | * (c) 2004 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: f-binpoly.c,v $ |
33 | * Revision 1.1.2.1 2004/03/21 22:39:46 mdw |
34 | * Elliptic curves on binary fields work. |
35 | * |
36 | */ |
37 | |
38 | /*----- Header files ------------------------------------------------------*/ |
39 | |
40 | #include <mLib/sub.h> |
41 | |
42 | #include "field.h" |
43 | #include "gf.h" |
44 | #include "gfreduce.h" |
45 | |
46 | /*----- Data structures ---------------------------------------------------*/ |
47 | |
48 | typedef struct fctx { |
49 | field f; |
50 | gfreduce r; |
51 | } fctx; |
52 | |
53 | /*----- Main code ---------------------------------------------------------*/ |
54 | |
55 | /* --- Field operations --- */ |
56 | |
57 | static void fdestroy(field *ff) |
58 | { |
59 | fctx *f = (fctx *)ff; |
60 | gfreduce_destroy(&f->r); |
61 | DESTROY(f); |
62 | } |
63 | |
64 | static int fzerop(field *ff, mp *x) |
65 | { |
66 | return (!MP_LEN(x)); |
67 | } |
68 | |
69 | static mp *fadd(field *ff, mp *d, mp *x, mp *y) |
70 | { |
71 | return (gf_add(d, x, y)); |
72 | } |
73 | |
74 | static mp *fmul(field *ff, mp *d, mp *x, mp *y) |
75 | { |
76 | fctx *f = (fctx *)ff; |
77 | d = gf_mul(d, x, y); |
78 | return (gfreduce_do(&f->r, d, d)); |
79 | } |
80 | |
81 | static mp *fsqr(field *ff, mp *d, mp *x) |
82 | { |
83 | fctx *f = (fctx *)ff; |
84 | d = gf_sqr(d, x); |
85 | return (gfreduce_do(&f->r, d, d)); |
86 | } |
87 | |
88 | static mp *finv(field *ff, mp *d, mp *x) |
89 | { |
90 | fctx *f = (fctx *)ff; |
91 | gf_gcd(0, 0, &d, f->r.p, x); |
92 | return (d); |
93 | } |
94 | |
95 | static mp *freduce(field *ff, mp *d, mp *x) |
96 | { |
97 | fctx *f = (fctx *)ff; |
98 | return (gfreduce_do(&f->r, d, x)); |
99 | } |
100 | |
101 | static mp *fsqrt(field *ff, mp *d, mp *x) |
102 | { |
103 | fctx *f = (fctx *)ff; |
104 | return (gfreduce_sqrt(&f->r, d, x)); |
105 | } |
106 | |
107 | static mp *fquadsolve(field *ff, mp *d, mp *x) |
108 | { |
109 | fctx *f = (fctx *)ff; |
110 | return (gfreduce_quadsolve(&f->r, d, x)); |
111 | } |
112 | |
113 | /* --- Field operations table --- */ |
114 | |
115 | static field_ops fops = { |
116 | fdestroy, |
117 | freduce, field_id, |
118 | fzerop, field_id, fadd, fadd, fmul, fsqr, finv, freduce, fsqrt, |
119 | fquadsolve, |
120 | 0, 0, 0, 0 |
121 | }; |
122 | |
123 | /* --- @field_binpoly@ --- * |
124 | * |
125 | * Arguments: @mp *p@ = the reduction polynomial |
126 | * |
127 | * Returns: A pointer to the field. |
128 | * |
129 | * Use: Creates a field structure for a binary field mod @p@. |
130 | */ |
131 | |
132 | field *field_binpoly(mp *p) |
133 | { |
134 | fctx *f = CREATE(fctx); |
135 | f->f.ops = &fops; |
136 | f->f.zero = MP_ZERO; |
137 | f->f.one = MP_ONE; |
138 | gfreduce_create(&f->r, p); |
139 | return (&f->f); |
140 | } |
141 | |
142 | /*----- That's all, folks -------------------------------------------------*/ |