1 /*
2 * ***** BEGIN LICENSE BLOCK *****
3 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
4 *
5 * The contents of this file are subject to the Mozilla Public License Version
6 * 1.1 (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 * http://www.mozilla.org/MPL/
9 *
10 * Software distributed under the License is distributed on an "AS IS" basis,
11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12 * for the specific language governing rights and limitations under the
13 * License.
14 *
15 * The Original Code is the elliptic curve math library for binary polynomial field curves.
16 *
17 * The Initial Developer of the Original Code is
18 * Sun Microsystems, Inc.
19 * Portions created by the Initial Developer are Copyright (C) 2003
20 * the Initial Developer. All Rights Reserved.
21 *
22 * Contributor(s):
23 * Sheueling Chang-Shantz <sheueling.chang@sun.com>,
24 * Stephen Fung <fungstep@hotmail.com>, and
25 * Douglas Stebila <douglas@stebila.ca>, Sun Microsystems Laboratories.
26 *
27 * Alternatively, the contents of this file may be used under the terms of
28 * either the GNU General Public License Version 2 or later (the "GPL"), or
29 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
30 * in which case the provisions of the GPL or the LGPL are applicable instead
31 * of those above. If you wish to allow use of your version of this file only
32 * under the terms of either the GPL or the LGPL, and not to allow others to
33 * use your version of this file under the terms of the MPL, indicate your
34 * decision by deleting the provisions above and replace them with the notice
35 * and other provisions required by the GPL or the LGPL. If you do not delete
36 * the provisions above, a recipient may use your version of this file under
37 * the terms of any one of the MPL, the GPL or the LGPL.
38 *
39 * ***** END LICENSE BLOCK ***** */
40 /*
41 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
42 * Use is subject to license terms.
43 *
44 * Sun elects to use this software under the MPL license.
45 */
46
47 #pragma ident "%Z%%M% %I% %E% SMI"
48
49 #include "ec2.h"
50 #include "mp_gf2m.h"
51 #include "mp_gf2m-priv.h"
52 #include "mpi.h"
53 #include "mpi-priv.h"
54 #ifndef _KERNEL
55 #include <stdlib.h>
56 #endif
57
58 /* Fast reduction for polynomials over a 163-bit curve. Assumes reduction
59 * polynomial with terms {163, 7, 6, 3, 0}. */
60 mp_err
ec_GF2m_163_mod(const mp_int * a,mp_int * r,const GFMethod * meth)61 ec_GF2m_163_mod(const mp_int *a, mp_int *r, const GFMethod *meth)
62 {
63 mp_err res = MP_OKAY;
64 mp_digit *u, z;
65
66 if (a != r) {
67 MP_CHECKOK(mp_copy(a, r));
68 }
69 #ifdef ECL_SIXTY_FOUR_BIT
70 if (MP_USED(r) < 6) {
71 MP_CHECKOK(s_mp_pad(r, 6));
72 }
73 u = MP_DIGITS(r);
74 MP_USED(r) = 6;
75
76 /* u[5] only has 6 significant bits */
77 z = u[5];
78 u[2] ^= (z << 36) ^ (z << 35) ^ (z << 32) ^ (z << 29);
79 z = u[4];
80 u[2] ^= (z >> 28) ^ (z >> 29) ^ (z >> 32) ^ (z >> 35);
81 u[1] ^= (z << 36) ^ (z << 35) ^ (z << 32) ^ (z << 29);
82 z = u[3];
83 u[1] ^= (z >> 28) ^ (z >> 29) ^ (z >> 32) ^ (z >> 35);
84 u[0] ^= (z << 36) ^ (z << 35) ^ (z << 32) ^ (z << 29);
85 z = u[2] >> 35; /* z only has 29 significant bits */
86 u[0] ^= (z << 7) ^ (z << 6) ^ (z << 3) ^ z;
87 /* clear bits above 163 */
88 u[5] = u[4] = u[3] = 0;
89 u[2] ^= z << 35;
90 #else
91 if (MP_USED(r) < 11) {
92 MP_CHECKOK(s_mp_pad(r, 11));
93 }
94 u = MP_DIGITS(r);
95 MP_USED(r) = 11;
96
97 /* u[11] only has 6 significant bits */
98 z = u[10];
99 u[5] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3);
100 u[4] ^= (z << 29);
101 z = u[9];
102 u[5] ^= (z >> 28) ^ (z >> 29);
103 u[4] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3);
104 u[3] ^= (z << 29);
105 z = u[8];
106 u[4] ^= (z >> 28) ^ (z >> 29);
107 u[3] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3);
108 u[2] ^= (z << 29);
109 z = u[7];
110 u[3] ^= (z >> 28) ^ (z >> 29);
111 u[2] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3);
112 u[1] ^= (z << 29);
113 z = u[6];
114 u[2] ^= (z >> 28) ^ (z >> 29);
115 u[1] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3);
116 u[0] ^= (z << 29);
117 z = u[5] >> 3; /* z only has 29 significant bits */
118 u[1] ^= (z >> 25) ^ (z >> 26);
119 u[0] ^= (z << 7) ^ (z << 6) ^ (z << 3) ^ z;
120 /* clear bits above 163 */
121 u[11] = u[10] = u[9] = u[8] = u[7] = u[6] = 0;
122 u[5] ^= z << 3;
123 #endif
124 s_mp_clamp(r);
125
126 CLEANUP:
127 return res;
128 }
129
130 /* Fast squaring for polynomials over a 163-bit curve. Assumes reduction
131 * polynomial with terms {163, 7, 6, 3, 0}. */
132 mp_err
ec_GF2m_163_sqr(const mp_int * a,mp_int * r,const GFMethod * meth)133 ec_GF2m_163_sqr(const mp_int *a, mp_int *r, const GFMethod *meth)
134 {
135 mp_err res = MP_OKAY;
136 mp_digit *u, *v;
137
138 v = MP_DIGITS(a);
139
140 #ifdef ECL_SIXTY_FOUR_BIT
141 if (MP_USED(a) < 3) {
142 return mp_bsqrmod(a, meth->irr_arr, r);
143 }
144 if (MP_USED(r) < 6) {
145 MP_CHECKOK(s_mp_pad(r, 6));
146 }
147 MP_USED(r) = 6;
148 #else
149 if (MP_USED(a) < 6) {
150 return mp_bsqrmod(a, meth->irr_arr, r);
151 }
152 if (MP_USED(r) < 12) {
153 MP_CHECKOK(s_mp_pad(r, 12));
154 }
155 MP_USED(r) = 12;
156 #endif
157 u = MP_DIGITS(r);
158
159 #ifdef ECL_THIRTY_TWO_BIT
160 u[11] = gf2m_SQR1(v[5]);
161 u[10] = gf2m_SQR0(v[5]);
162 u[9] = gf2m_SQR1(v[4]);
163 u[8] = gf2m_SQR0(v[4]);
164 u[7] = gf2m_SQR1(v[3]);
165 u[6] = gf2m_SQR0(v[3]);
166 #endif
167 u[5] = gf2m_SQR1(v[2]);
168 u[4] = gf2m_SQR0(v[2]);
169 u[3] = gf2m_SQR1(v[1]);
170 u[2] = gf2m_SQR0(v[1]);
171 u[1] = gf2m_SQR1(v[0]);
172 u[0] = gf2m_SQR0(v[0]);
173 return ec_GF2m_163_mod(r, r, meth);
174
175 CLEANUP:
176 return res;
177 }
178
179 /* Fast multiplication for polynomials over a 163-bit curve. Assumes
180 * reduction polynomial with terms {163, 7, 6, 3, 0}. */
181 mp_err
ec_GF2m_163_mul(const mp_int * a,const mp_int * b,mp_int * r,const GFMethod * meth)182 ec_GF2m_163_mul(const mp_int *a, const mp_int *b, mp_int *r,
183 const GFMethod *meth)
184 {
185 mp_err res = MP_OKAY;
186 mp_digit a2 = 0, a1 = 0, a0, b2 = 0, b1 = 0, b0;
187
188 #ifdef ECL_THIRTY_TWO_BIT
189 mp_digit a5 = 0, a4 = 0, a3 = 0, b5 = 0, b4 = 0, b3 = 0;
190 mp_digit rm[6];
191 #endif
192
193 if (a == b) {
194 return ec_GF2m_163_sqr(a, r, meth);
195 } else {
196 switch (MP_USED(a)) {
197 #ifdef ECL_THIRTY_TWO_BIT
198 case 6:
199 a5 = MP_DIGIT(a, 5);
200 case 5:
201 a4 = MP_DIGIT(a, 4);
202 case 4:
203 a3 = MP_DIGIT(a, 3);
204 #endif
205 case 3:
206 a2 = MP_DIGIT(a, 2);
207 case 2:
208 a1 = MP_DIGIT(a, 1);
209 default:
210 a0 = MP_DIGIT(a, 0);
211 }
212 switch (MP_USED(b)) {
213 #ifdef ECL_THIRTY_TWO_BIT
214 case 6:
215 b5 = MP_DIGIT(b, 5);
216 case 5:
217 b4 = MP_DIGIT(b, 4);
218 case 4:
219 b3 = MP_DIGIT(b, 3);
220 #endif
221 case 3:
222 b2 = MP_DIGIT(b, 2);
223 case 2:
224 b1 = MP_DIGIT(b, 1);
225 default:
226 b0 = MP_DIGIT(b, 0);
227 }
228 #ifdef ECL_SIXTY_FOUR_BIT
229 MP_CHECKOK(s_mp_pad(r, 6));
230 s_bmul_3x3(MP_DIGITS(r), a2, a1, a0, b2, b1, b0);
231 MP_USED(r) = 6;
232 s_mp_clamp(r);
233 #else
234 MP_CHECKOK(s_mp_pad(r, 12));
235 s_bmul_3x3(MP_DIGITS(r) + 6, a5, a4, a3, b5, b4, b3);
236 s_bmul_3x3(MP_DIGITS(r), a2, a1, a0, b2, b1, b0);
237 s_bmul_3x3(rm, a5 ^ a2, a4 ^ a1, a3 ^ a0, b5 ^ b2, b4 ^ b1,
238 b3 ^ b0);
239 rm[5] ^= MP_DIGIT(r, 5) ^ MP_DIGIT(r, 11);
240 rm[4] ^= MP_DIGIT(r, 4) ^ MP_DIGIT(r, 10);
241 rm[3] ^= MP_DIGIT(r, 3) ^ MP_DIGIT(r, 9);
242 rm[2] ^= MP_DIGIT(r, 2) ^ MP_DIGIT(r, 8);
243 rm[1] ^= MP_DIGIT(r, 1) ^ MP_DIGIT(r, 7);
244 rm[0] ^= MP_DIGIT(r, 0) ^ MP_DIGIT(r, 6);
245 MP_DIGIT(r, 8) ^= rm[5];
246 MP_DIGIT(r, 7) ^= rm[4];
247 MP_DIGIT(r, 6) ^= rm[3];
248 MP_DIGIT(r, 5) ^= rm[2];
249 MP_DIGIT(r, 4) ^= rm[1];
250 MP_DIGIT(r, 3) ^= rm[0];
251 MP_USED(r) = 12;
252 s_mp_clamp(r);
253 #endif
254 return ec_GF2m_163_mod(r, r, meth);
255 }
256
257 CLEANUP:
258 return res;
259 }
260
261 /* Wire in fast field arithmetic for 163-bit curves. */
262 mp_err
ec_group_set_gf2m163(ECGroup * group,ECCurveName name)263 ec_group_set_gf2m163(ECGroup *group, ECCurveName name)
264 {
265 group->meth->field_mod = &ec_GF2m_163_mod;
266 group->meth->field_mul = &ec_GF2m_163_mul;
267 group->meth->field_sqr = &ec_GF2m_163_sqr;
268 return MP_OKAY;
269 }
270