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 233-bit curve. Assumes reduction 59 * polynomial with terms {233, 74, 0}. */ 60 mp_err 61 ec_GF2m_233_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) < 8) { 71 MP_CHECKOK(s_mp_pad(r, 8)); 72 } 73 u = MP_DIGITS(r); 74 MP_USED(r) = 8; 75 76 /* u[7] only has 18 significant bits */ 77 z = u[7]; 78 u[4] ^= (z << 33) ^ (z >> 41); 79 u[3] ^= (z << 23); 80 z = u[6]; 81 u[4] ^= (z >> 31); 82 u[3] ^= (z << 33) ^ (z >> 41); 83 u[2] ^= (z << 23); 84 z = u[5]; 85 u[3] ^= (z >> 31); 86 u[2] ^= (z << 33) ^ (z >> 41); 87 u[1] ^= (z << 23); 88 z = u[4]; 89 u[2] ^= (z >> 31); 90 u[1] ^= (z << 33) ^ (z >> 41); 91 u[0] ^= (z << 23); 92 z = u[3] >> 41; /* z only has 23 significant bits */ 93 u[1] ^= (z << 10); 94 u[0] ^= z; 95 /* clear bits above 233 */ 96 u[7] = u[6] = u[5] = u[4] = 0; 97 u[3] ^= z << 41; 98 #else 99 if (MP_USED(r) < 15) { 100 MP_CHECKOK(s_mp_pad(r, 15)); 101 } 102 u = MP_DIGITS(r); 103 MP_USED(r) = 15; 104 105 /* u[14] only has 18 significant bits */ 106 z = u[14]; 107 u[9] ^= (z << 1); 108 u[7] ^= (z >> 9); 109 u[6] ^= (z << 23); 110 z = u[13]; 111 u[9] ^= (z >> 31); 112 u[8] ^= (z << 1); 113 u[6] ^= (z >> 9); 114 u[5] ^= (z << 23); 115 z = u[12]; 116 u[8] ^= (z >> 31); 117 u[7] ^= (z << 1); 118 u[5] ^= (z >> 9); 119 u[4] ^= (z << 23); 120 z = u[11]; 121 u[7] ^= (z >> 31); 122 u[6] ^= (z << 1); 123 u[4] ^= (z >> 9); 124 u[3] ^= (z << 23); 125 z = u[10]; 126 u[6] ^= (z >> 31); 127 u[5] ^= (z << 1); 128 u[3] ^= (z >> 9); 129 u[2] ^= (z << 23); 130 z = u[9]; 131 u[5] ^= (z >> 31); 132 u[4] ^= (z << 1); 133 u[2] ^= (z >> 9); 134 u[1] ^= (z << 23); 135 z = u[8]; 136 u[4] ^= (z >> 31); 137 u[3] ^= (z << 1); 138 u[1] ^= (z >> 9); 139 u[0] ^= (z << 23); 140 z = u[7] >> 9; /* z only has 23 significant bits */ 141 u[3] ^= (z >> 22); 142 u[2] ^= (z << 10); 143 u[0] ^= z; 144 /* clear bits above 233 */ 145 u[14] = u[13] = u[12] = u[11] = u[10] = u[9] = u[8] = 0; 146 u[7] ^= z << 9; 147 #endif 148 s_mp_clamp(r); 149 150 CLEANUP: 151 return res; 152 } 153 154 /* Fast squaring for polynomials over a 233-bit curve. Assumes reduction 155 * polynomial with terms {233, 74, 0}. */ 156 mp_err 157 ec_GF2m_233_sqr(const mp_int *a, mp_int *r, const GFMethod *meth) 158 { 159 mp_err res = MP_OKAY; 160 mp_digit *u, *v; 161 162 v = MP_DIGITS(a); 163 164 #ifdef ECL_SIXTY_FOUR_BIT 165 if (MP_USED(a) < 4) { 166 return mp_bsqrmod(a, meth->irr_arr, r); 167 } 168 if (MP_USED(r) < 8) { 169 MP_CHECKOK(s_mp_pad(r, 8)); 170 } 171 MP_USED(r) = 8; 172 #else 173 if (MP_USED(a) < 8) { 174 return mp_bsqrmod(a, meth->irr_arr, r); 175 } 176 if (MP_USED(r) < 15) { 177 MP_CHECKOK(s_mp_pad(r, 15)); 178 } 179 MP_USED(r) = 15; 180 #endif 181 u = MP_DIGITS(r); 182 183 #ifdef ECL_THIRTY_TWO_BIT 184 u[14] = gf2m_SQR0(v[7]); 185 u[13] = gf2m_SQR1(v[6]); 186 u[12] = gf2m_SQR0(v[6]); 187 u[11] = gf2m_SQR1(v[5]); 188 u[10] = gf2m_SQR0(v[5]); 189 u[9] = gf2m_SQR1(v[4]); 190 u[8] = gf2m_SQR0(v[4]); 191 #endif 192 u[7] = gf2m_SQR1(v[3]); 193 u[6] = gf2m_SQR0(v[3]); 194 u[5] = gf2m_SQR1(v[2]); 195 u[4] = gf2m_SQR0(v[2]); 196 u[3] = gf2m_SQR1(v[1]); 197 u[2] = gf2m_SQR0(v[1]); 198 u[1] = gf2m_SQR1(v[0]); 199 u[0] = gf2m_SQR0(v[0]); 200 return ec_GF2m_233_mod(r, r, meth); 201 202 CLEANUP: 203 return res; 204 } 205 206 /* Fast multiplication for polynomials over a 233-bit curve. Assumes 207 * reduction polynomial with terms {233, 74, 0}. */ 208 mp_err 209 ec_GF2m_233_mul(const mp_int *a, const mp_int *b, mp_int *r, 210 const GFMethod *meth) 211 { 212 mp_err res = MP_OKAY; 213 mp_digit a3 = 0, a2 = 0, a1 = 0, a0, b3 = 0, b2 = 0, b1 = 0, b0; 214 215 #ifdef ECL_THIRTY_TWO_BIT 216 mp_digit a7 = 0, a6 = 0, a5 = 0, a4 = 0, b7 = 0, b6 = 0, b5 = 0, b4 = 217 0; 218 mp_digit rm[8]; 219 #endif 220 221 if (a == b) { 222 return ec_GF2m_233_sqr(a, r, meth); 223 } else { 224 switch (MP_USED(a)) { 225 #ifdef ECL_THIRTY_TWO_BIT 226 case 8: 227 a7 = MP_DIGIT(a, 7); 228 case 7: 229 a6 = MP_DIGIT(a, 6); 230 case 6: 231 a5 = MP_DIGIT(a, 5); 232 case 5: 233 a4 = MP_DIGIT(a, 4); 234 #endif 235 case 4: 236 a3 = MP_DIGIT(a, 3); 237 case 3: 238 a2 = MP_DIGIT(a, 2); 239 case 2: 240 a1 = MP_DIGIT(a, 1); 241 default: 242 a0 = MP_DIGIT(a, 0); 243 } 244 switch (MP_USED(b)) { 245 #ifdef ECL_THIRTY_TWO_BIT 246 case 8: 247 b7 = MP_DIGIT(b, 7); 248 case 7: 249 b6 = MP_DIGIT(b, 6); 250 case 6: 251 b5 = MP_DIGIT(b, 5); 252 case 5: 253 b4 = MP_DIGIT(b, 4); 254 #endif 255 case 4: 256 b3 = MP_DIGIT(b, 3); 257 case 3: 258 b2 = MP_DIGIT(b, 2); 259 case 2: 260 b1 = MP_DIGIT(b, 1); 261 default: 262 b0 = MP_DIGIT(b, 0); 263 } 264 #ifdef ECL_SIXTY_FOUR_BIT 265 MP_CHECKOK(s_mp_pad(r, 8)); 266 s_bmul_4x4(MP_DIGITS(r), a3, a2, a1, a0, b3, b2, b1, b0); 267 MP_USED(r) = 8; 268 s_mp_clamp(r); 269 #else 270 MP_CHECKOK(s_mp_pad(r, 16)); 271 s_bmul_4x4(MP_DIGITS(r) + 8, a7, a6, a5, a4, b7, b6, b5, b4); 272 s_bmul_4x4(MP_DIGITS(r), a3, a2, a1, a0, b3, b2, b1, b0); 273 s_bmul_4x4(rm, a7 ^ a3, a6 ^ a2, a5 ^ a1, a4 ^ a0, b7 ^ b3, 274 b6 ^ b2, b5 ^ b1, b4 ^ b0); 275 rm[7] ^= MP_DIGIT(r, 7) ^ MP_DIGIT(r, 15); 276 rm[6] ^= MP_DIGIT(r, 6) ^ MP_DIGIT(r, 14); 277 rm[5] ^= MP_DIGIT(r, 5) ^ MP_DIGIT(r, 13); 278 rm[4] ^= MP_DIGIT(r, 4) ^ MP_DIGIT(r, 12); 279 rm[3] ^= MP_DIGIT(r, 3) ^ MP_DIGIT(r, 11); 280 rm[2] ^= MP_DIGIT(r, 2) ^ MP_DIGIT(r, 10); 281 rm[1] ^= MP_DIGIT(r, 1) ^ MP_DIGIT(r, 9); 282 rm[0] ^= MP_DIGIT(r, 0) ^ MP_DIGIT(r, 8); 283 MP_DIGIT(r, 11) ^= rm[7]; 284 MP_DIGIT(r, 10) ^= rm[6]; 285 MP_DIGIT(r, 9) ^= rm[5]; 286 MP_DIGIT(r, 8) ^= rm[4]; 287 MP_DIGIT(r, 7) ^= rm[3]; 288 MP_DIGIT(r, 6) ^= rm[2]; 289 MP_DIGIT(r, 5) ^= rm[1]; 290 MP_DIGIT(r, 4) ^= rm[0]; 291 MP_USED(r) = 16; 292 s_mp_clamp(r); 293 #endif 294 return ec_GF2m_233_mod(r, r, meth); 295 } 296 297 CLEANUP: 298 return res; 299 } 300 301 /* Wire in fast field arithmetic for 233-bit curves. */ 302 mp_err 303 ec_group_set_gf2m233(ECGroup *group, ECCurveName name) 304 { 305 group->meth->field_mod = &ec_GF2m_233_mod; 306 group->meth->field_mul = &ec_GF2m_233_mul; 307 group->meth->field_sqr = &ec_GF2m_233_sqr; 308 return MP_OKAY; 309 } 310