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 #include "ec2.h" 48 #include "mp_gf2m.h" 49 #include "mp_gf2m-priv.h" 50 #include "mpi.h" 51 #include "mpi-priv.h" 52 #ifndef _KERNEL 53 #include <stdlib.h> 54 #endif 55 56 /* Fast reduction for polynomials over a 233-bit curve. Assumes reduction 57 * polynomial with terms {233, 74, 0}. */ 58 mp_err 59 ec_GF2m_233_mod(const mp_int *a, mp_int *r, const GFMethod *meth) 60 { 61 mp_err res = MP_OKAY; 62 mp_digit *u, z; 63 64 if (a != r) { 65 MP_CHECKOK(mp_copy(a, r)); 66 } 67 #ifdef ECL_SIXTY_FOUR_BIT 68 if (MP_USED(r) < 8) { 69 MP_CHECKOK(s_mp_pad(r, 8)); 70 } 71 u = MP_DIGITS(r); 72 MP_USED(r) = 8; 73 74 /* u[7] only has 18 significant bits */ 75 z = u[7]; 76 u[4] ^= (z << 33) ^ (z >> 41); 77 u[3] ^= (z << 23); 78 z = u[6]; 79 u[4] ^= (z >> 31); 80 u[3] ^= (z << 33) ^ (z >> 41); 81 u[2] ^= (z << 23); 82 z = u[5]; 83 u[3] ^= (z >> 31); 84 u[2] ^= (z << 33) ^ (z >> 41); 85 u[1] ^= (z << 23); 86 z = u[4]; 87 u[2] ^= (z >> 31); 88 u[1] ^= (z << 33) ^ (z >> 41); 89 u[0] ^= (z << 23); 90 z = u[3] >> 41; /* z only has 23 significant bits */ 91 u[1] ^= (z << 10); 92 u[0] ^= z; 93 /* clear bits above 233 */ 94 u[7] = u[6] = u[5] = u[4] = 0; 95 u[3] ^= z << 41; 96 #else 97 if (MP_USED(r) < 15) { 98 MP_CHECKOK(s_mp_pad(r, 15)); 99 } 100 u = MP_DIGITS(r); 101 MP_USED(r) = 15; 102 103 /* u[14] only has 18 significant bits */ 104 z = u[14]; 105 u[9] ^= (z << 1); 106 u[7] ^= (z >> 9); 107 u[6] ^= (z << 23); 108 z = u[13]; 109 u[9] ^= (z >> 31); 110 u[8] ^= (z << 1); 111 u[6] ^= (z >> 9); 112 u[5] ^= (z << 23); 113 z = u[12]; 114 u[8] ^= (z >> 31); 115 u[7] ^= (z << 1); 116 u[5] ^= (z >> 9); 117 u[4] ^= (z << 23); 118 z = u[11]; 119 u[7] ^= (z >> 31); 120 u[6] ^= (z << 1); 121 u[4] ^= (z >> 9); 122 u[3] ^= (z << 23); 123 z = u[10]; 124 u[6] ^= (z >> 31); 125 u[5] ^= (z << 1); 126 u[3] ^= (z >> 9); 127 u[2] ^= (z << 23); 128 z = u[9]; 129 u[5] ^= (z >> 31); 130 u[4] ^= (z << 1); 131 u[2] ^= (z >> 9); 132 u[1] ^= (z << 23); 133 z = u[8]; 134 u[4] ^= (z >> 31); 135 u[3] ^= (z << 1); 136 u[1] ^= (z >> 9); 137 u[0] ^= (z << 23); 138 z = u[7] >> 9; /* z only has 23 significant bits */ 139 u[3] ^= (z >> 22); 140 u[2] ^= (z << 10); 141 u[0] ^= z; 142 /* clear bits above 233 */ 143 u[14] = u[13] = u[12] = u[11] = u[10] = u[9] = u[8] = 0; 144 u[7] ^= z << 9; 145 #endif 146 s_mp_clamp(r); 147 148 CLEANUP: 149 return res; 150 } 151 152 /* Fast squaring for polynomials over a 233-bit curve. Assumes reduction 153 * polynomial with terms {233, 74, 0}. */ 154 mp_err 155 ec_GF2m_233_sqr(const mp_int *a, mp_int *r, const GFMethod *meth) 156 { 157 mp_err res = MP_OKAY; 158 mp_digit *u, *v; 159 160 v = MP_DIGITS(a); 161 162 #ifdef ECL_SIXTY_FOUR_BIT 163 if (MP_USED(a) < 4) { 164 return mp_bsqrmod(a, meth->irr_arr, r); 165 } 166 if (MP_USED(r) < 8) { 167 MP_CHECKOK(s_mp_pad(r, 8)); 168 } 169 MP_USED(r) = 8; 170 #else 171 if (MP_USED(a) < 8) { 172 return mp_bsqrmod(a, meth->irr_arr, r); 173 } 174 if (MP_USED(r) < 15) { 175 MP_CHECKOK(s_mp_pad(r, 15)); 176 } 177 MP_USED(r) = 15; 178 #endif 179 u = MP_DIGITS(r); 180 181 #ifdef ECL_THIRTY_TWO_BIT 182 u[14] = gf2m_SQR0(v[7]); 183 u[13] = gf2m_SQR1(v[6]); 184 u[12] = gf2m_SQR0(v[6]); 185 u[11] = gf2m_SQR1(v[5]); 186 u[10] = gf2m_SQR0(v[5]); 187 u[9] = gf2m_SQR1(v[4]); 188 u[8] = gf2m_SQR0(v[4]); 189 #endif 190 u[7] = gf2m_SQR1(v[3]); 191 u[6] = gf2m_SQR0(v[3]); 192 u[5] = gf2m_SQR1(v[2]); 193 u[4] = gf2m_SQR0(v[2]); 194 u[3] = gf2m_SQR1(v[1]); 195 u[2] = gf2m_SQR0(v[1]); 196 u[1] = gf2m_SQR1(v[0]); 197 u[0] = gf2m_SQR0(v[0]); 198 return ec_GF2m_233_mod(r, r, meth); 199 200 CLEANUP: 201 return res; 202 } 203 204 /* Fast multiplication for polynomials over a 233-bit curve. Assumes 205 * reduction polynomial with terms {233, 74, 0}. */ 206 mp_err 207 ec_GF2m_233_mul(const mp_int *a, const mp_int *b, mp_int *r, 208 const GFMethod *meth) 209 { 210 mp_err res = MP_OKAY; 211 mp_digit a3 = 0, a2 = 0, a1 = 0, a0, b3 = 0, b2 = 0, b1 = 0, b0; 212 213 #ifdef ECL_THIRTY_TWO_BIT 214 mp_digit a7 = 0, a6 = 0, a5 = 0, a4 = 0, b7 = 0, b6 = 0, b5 = 0, b4 = 215 0; 216 mp_digit rm[8]; 217 #endif 218 219 if (a == b) { 220 return ec_GF2m_233_sqr(a, r, meth); 221 } else { 222 switch (MP_USED(a)) { 223 #ifdef ECL_THIRTY_TWO_BIT 224 case 8: 225 a7 = MP_DIGIT(a, 7); 226 /* FALLTHROUGH */ 227 case 7: 228 a6 = MP_DIGIT(a, 6); 229 /* FALLTHROUGH */ 230 case 6: 231 a5 = MP_DIGIT(a, 5); 232 /* FALLTHROUGH */ 233 case 5: 234 a4 = MP_DIGIT(a, 4); 235 #endif 236 /* FALLTHROUGH */ 237 case 4: 238 a3 = MP_DIGIT(a, 3); 239 /* FALLTHROUGH */ 240 case 3: 241 a2 = MP_DIGIT(a, 2); 242 /* FALLTHROUGH */ 243 case 2: 244 a1 = MP_DIGIT(a, 1); 245 /* FALLTHROUGH */ 246 default: 247 a0 = MP_DIGIT(a, 0); 248 } 249 switch (MP_USED(b)) { 250 #ifdef ECL_THIRTY_TWO_BIT 251 case 8: 252 b7 = MP_DIGIT(b, 7); 253 /* FALLTHROUGH */ 254 case 7: 255 b6 = MP_DIGIT(b, 6); 256 /* FALLTHROUGH */ 257 case 6: 258 b5 = MP_DIGIT(b, 5); 259 /* FALLTHROUGH */ 260 case 5: 261 b4 = MP_DIGIT(b, 4); 262 #endif 263 /* FALLTHROUGH */ 264 case 4: 265 b3 = MP_DIGIT(b, 3); 266 /* FALLTHROUGH */ 267 case 3: 268 b2 = MP_DIGIT(b, 2); 269 /* FALLTHROUGH */ 270 case 2: 271 b1 = MP_DIGIT(b, 1); 272 /* FALLTHROUGH */ 273 default: 274 b0 = MP_DIGIT(b, 0); 275 } 276 #ifdef ECL_SIXTY_FOUR_BIT 277 MP_CHECKOK(s_mp_pad(r, 8)); 278 s_bmul_4x4(MP_DIGITS(r), a3, a2, a1, a0, b3, b2, b1, b0); 279 MP_USED(r) = 8; 280 s_mp_clamp(r); 281 #else 282 MP_CHECKOK(s_mp_pad(r, 16)); 283 s_bmul_4x4(MP_DIGITS(r) + 8, a7, a6, a5, a4, b7, b6, b5, b4); 284 s_bmul_4x4(MP_DIGITS(r), a3, a2, a1, a0, b3, b2, b1, b0); 285 s_bmul_4x4(rm, a7 ^ a3, a6 ^ a2, a5 ^ a1, a4 ^ a0, b7 ^ b3, 286 b6 ^ b2, b5 ^ b1, b4 ^ b0); 287 rm[7] ^= MP_DIGIT(r, 7) ^ MP_DIGIT(r, 15); 288 rm[6] ^= MP_DIGIT(r, 6) ^ MP_DIGIT(r, 14); 289 rm[5] ^= MP_DIGIT(r, 5) ^ MP_DIGIT(r, 13); 290 rm[4] ^= MP_DIGIT(r, 4) ^ MP_DIGIT(r, 12); 291 rm[3] ^= MP_DIGIT(r, 3) ^ MP_DIGIT(r, 11); 292 rm[2] ^= MP_DIGIT(r, 2) ^ MP_DIGIT(r, 10); 293 rm[1] ^= MP_DIGIT(r, 1) ^ MP_DIGIT(r, 9); 294 rm[0] ^= MP_DIGIT(r, 0) ^ MP_DIGIT(r, 8); 295 MP_DIGIT(r, 11) ^= rm[7]; 296 MP_DIGIT(r, 10) ^= rm[6]; 297 MP_DIGIT(r, 9) ^= rm[5]; 298 MP_DIGIT(r, 8) ^= rm[4]; 299 MP_DIGIT(r, 7) ^= rm[3]; 300 MP_DIGIT(r, 6) ^= rm[2]; 301 MP_DIGIT(r, 5) ^= rm[1]; 302 MP_DIGIT(r, 4) ^= rm[0]; 303 MP_USED(r) = 16; 304 s_mp_clamp(r); 305 #endif 306 return ec_GF2m_233_mod(r, r, meth); 307 } 308 309 CLEANUP: 310 return res; 311 } 312 313 /* Wire in fast field arithmetic for 233-bit curves. */ 314 mp_err 315 ec_group_set_gf2m233(ECGroup *group, ECCurveName name) 316 { 317 group->meth->field_mod = &ec_GF2m_233_mod; 318 group->meth->field_mul = &ec_GF2m_233_mul; 319 group->meth->field_sqr = &ec_GF2m_233_sqr; 320 return MP_OKAY; 321 } 322