xref: /titanic_51/usr/src/common/crypto/ecc/ec2_163.c (revision bbaa8b60dd95d714741fc474adad3cf710ef4efd)
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
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
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
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
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