ceb3f0c0 |
1 | /* -*-apcalc-*- |
2 | * |
3 | * $Id: ec2.cal,v 1.1.2.1 2004/03/21 22:39:46 mdw Exp $ |
4 | * |
5 | * Testbed for elliptic curve arithmetic over binary fields |
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: ec2.cal,v $ |
33 | * Revision 1.1.2.1 2004/03/21 22:39:46 mdw |
34 | * Elliptic curves on binary fields work. |
35 | * |
36 | * Revision 1.1.4.2 2004/03/20 00:13:31 mdw |
37 | * Projective coordinates for prime curves |
38 | * |
39 | * Revision 1.1.4.1 2003/06/10 13:43:53 mdw |
40 | * Simple (non-projective) curves over prime fields now seem to work. |
41 | * |
42 | * Revision 1.1 2000/10/08 16:01:37 mdw |
43 | * Prototypes of various bits of code. |
44 | * |
45 | */ |
46 | |
47 | /*----- Object types ------------------------------------------------------*/ |
48 | |
49 | obj ec2_curve { a, b, p }; |
50 | obj ec2_pt { x, y, e }; |
51 | obj ecpp_pt { x, y, z, e }; |
52 | |
53 | /*----- Main code ---------------------------------------------------------*/ |
54 | |
55 | define ec2_curve(a, b, p) |
56 | { |
57 | local obj ec2_curve e; |
58 | e.a = a; |
59 | e.b = b; |
60 | e.p = p; |
61 | return (e); |
62 | } |
63 | |
64 | define ec2_pt(x, y, e) |
65 | { |
66 | local obj ec2_pt p; |
67 | p.x = x % e.p; |
68 | p.y = y % e.p; |
69 | p.e = e; |
70 | return (p); |
71 | } |
72 | |
73 | define ec2_pt_print(a) |
74 | { |
75 | print "(" : a.x : ", " : a.y : ")" :; |
76 | } |
77 | |
78 | define ec2_pt_add(a, b) |
79 | { |
80 | local e, alpha; |
81 | local obj ec2_pt d; |
82 | |
83 | print "> ecadd: ", a, b; |
84 | if (a == 0) |
85 | d = b; |
86 | else if (b == 0) |
87 | d = a; |
88 | else if (!istype(a, b)) |
89 | quit "bad type arguments to ec2_pt_add"; |
90 | else if (a.e != b.e) |
91 | quit "points from different curves in ec2_pt_add"; |
92 | else { |
93 | e = a.e; |
94 | if (a.x != b.x) { |
95 | alpha = ((a.y + b.y) * gf_inv(a.x + b.x, e.p)) % e.p; |
96 | d.x = (e.a + alpha^2 + alpha + a.x + b.x) % e.p; |
97 | } else if (a.y != b.y || a.x == gf(0)) |
98 | return 0; |
99 | else { |
100 | alpha = a.x + a.y * gf_inv(a.x, e.p) % e.p; |
101 | d.x = (e.a + alpha^2 + alpha) % e.p; |
102 | } |
103 | d.y = ((a.x + d.x) * alpha + d.x + a.y) % e.p; |
104 | d.e = e; |
105 | } |
106 | |
107 | print "< ecadd: ", d; |
108 | return (d); |
109 | } |
110 | |
111 | define ec2_pt_dbl(a) |
112 | { |
113 | local e, alpha; |
114 | local obj ec2_pt d; |
115 | print "> ecdbl: ", a; |
116 | if (istype(a, 1)) |
117 | return (0); |
118 | e = a.e; |
119 | alpha = a.x + a.y * gf_inv(a.x, e.p) % e.p; |
120 | d.x = (e.a + alpha^2 + alpha) % e.p; |
121 | d.y = ((a.x + d.x) * alpha + d.x + a.y) % e.p; |
122 | d.e = e; |
123 | print "< ecdbl: ", d; |
124 | return (d); |
125 | } |
126 | |
127 | define ec2_pt_sub(a, b) { return ec2_pt_add(a, ec2_pt_neg(b)); } |
128 | |
129 | define ec2_pt_neg(a) |
130 | { |
131 | local obj ec2_pt d; |
132 | d.x = a.x; |
133 | d.y = a.x + a.y; |
134 | d.e = a.e; |
135 | return (d); |
136 | } |
137 | |
138 | define ec2_pt_check(a) |
139 | { |
140 | local e; |
141 | |
142 | e = a.e; |
143 | if ((a.y^2 + a.x * a.y) % e.p != (a.x^3 + e.a * a.x^2 + e.b) % e.p) |
144 | quit "bad curve point"; |
145 | } |
146 | |
147 | define ec2_pt_mul(a, b) |
148 | { |
149 | local p, n; |
150 | local d; |
151 | |
152 | if (istype(a, 1)) { |
153 | n = a; |
154 | p = b; |
155 | } else if (istype(b, 1)) { |
156 | n = b; |
157 | p = a; |
158 | } else |
159 | return (newerror("bad arguments to ec2_pt_mul")); |
160 | |
161 | d = 0; |
162 | while (n) { |
163 | if (n & 1) |
164 | d += p; |
165 | n >>= 1; |
166 | p = ec2_pt_dbl(p); |
167 | } |
168 | return (d); |
169 | } |
170 | |
171 | /*----- FIPS186-2 standard curves -----------------------------------------*/ |
172 | |
173 | b163 = ec2_curve(gf(1),gf(0x20a601907b8c953ca1481eb10512f78744a3205fd), |
174 | gf(0x800000000000000000000000000000000000000c9)); |
175 | b163_r = 5846006549323611672814742442876390689256843201587; |
176 | b163_g = ec2_pt(0x3f0eba16286a2d57ea0991168d4994637e8343e36, |
177 | 0x0d51fbc6c71a0094fa2cdd545b11c5c0c797324f1, b163); |
178 | |
179 | /*----- That's all, folks -------------------------------------------------*/ |
180 | |