usr/src/common/crypto/ecc/ec2_163.c

   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 163-bit curve. Assumes reduction
  57  * polynomial with terms {163, 7, 6, 3, 0}. */
  58 mp_err
  59 ec_GF2m_163_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) < 6) {
  69                 MP_CHECKOK(s_mp_pad(r, 6));
  70         }
  71         u = MP_DIGITS(r);
  72         MP_USED(r) = 6;
  73
  74         /* u[5] only has 6 significant bits */
  75         z = u[5];
  76         u[2] ^= (z << 36) ^ (z << 35) ^ (z << 32) ^ (z << 29);
  77         z = u[4];
  78         u[2] ^= (z >> 28) ^ (z >> 29) ^ (z >> 32) ^ (z >> 35);
  79         u[1] ^= (z << 36) ^ (z << 35) ^ (z << 32) ^ (z << 29);
  80         z = u[3];
  81         u[1] ^= (z >> 28) ^ (z >> 29) ^ (z >> 32) ^ (z >> 35);
  82         u[0] ^= (z << 36) ^ (z << 35) ^ (z << 32) ^ (z << 29);
  83         z = u[2] >> 35;                         /* z only has 29 significant bits */
  84         u[0] ^= (z << 7) ^ (z << 6) ^ (z << 3) ^ z;
  85         /* clear bits above 163 */
  86         u[5] = u[4] = u[3] = 0;
  87         u[2] ^= z << 35;
  88 #else
  89         if (MP_USED(r) < 11) {
  90                 MP_CHECKOK(s_mp_pad(r, 11));
  91         }
  92         u = MP_DIGITS(r);
  93         MP_USED(r) = 11;
  94
  95         /* u[11] only has 6 significant bits */
  96         z = u[10];
  97         u[5] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3);
  98         u[4] ^= (z << 29);
  99         z = u[9];
 100         u[5] ^= (z >> 28) ^ (z >> 29);
 101         u[4] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3);
 102         u[3] ^= (z << 29);
 103         z = u[8];
 104         u[4] ^= (z >> 28) ^ (z >> 29);
 105         u[3] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3);
 106         u[2] ^= (z << 29);
 107         z = u[7];
 108         u[3] ^= (z >> 28) ^ (z >> 29);
 109         u[2] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3);
 110         u[1] ^= (z << 29);
 111         z = u[6];
 112         u[2] ^= (z >> 28) ^ (z >> 29);
 113         u[1] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3);
 114         u[0] ^= (z << 29);
 115         z = u[5] >> 3;                          /* z only has 29 significant bits */
 116         u[1] ^= (z >> 25) ^ (z >> 26);
 117         u[0] ^= (z << 7) ^ (z << 6) ^ (z << 3) ^ z;
 118         /* clear bits above 163 */
 119         u[11] = u[10] = u[9] = u[8] = u[7] = u[6] = 0;
 120         u[5] ^= z << 3;
 121 #endif
 122         s_mp_clamp(r);
 123
 124   CLEANUP:
 125         return res;
 126 }
 127
 128 /* Fast squaring for polynomials over a 163-bit curve. Assumes reduction
 129  * polynomial with terms {163, 7, 6, 3, 0}. */
 130 mp_err
 131 ec_GF2m_163_sqr(const mp_int *a, mp_int *r, const GFMethod *meth)
 132 {
 133         mp_err res = MP_OKAY;
 134         mp_digit *u, *v;
 135
 136         v = MP_DIGITS(a);
 137
 138 #ifdef ECL_SIXTY_FOUR_BIT
 139         if (MP_USED(a) < 3) {
 140                 return mp_bsqrmod(a, meth->irr_arr, r);
 141         }
 142         if (MP_USED(r) < 6) {
 143                 MP_CHECKOK(s_mp_pad(r, 6));
 144         }
 145         MP_USED(r) = 6;
 146 #else
 147         if (MP_USED(a) < 6) {
 148                 return mp_bsqrmod(a, meth->irr_arr, r);
 149         }
 150         if (MP_USED(r) < 12) {
 151                 MP_CHECKOK(s_mp_pad(r, 12));
 152         }
 153         MP_USED(r) = 12;
 154 #endif
 155         u = MP_DIGITS(r);
 156
 157 #ifdef ECL_THIRTY_TWO_BIT
 158         u[11] = gf2m_SQR1(v[5]);
 159         u[10] = gf2m_SQR0(v[5]);
 160         u[9] = gf2m_SQR1(v[4]);
 161         u[8] = gf2m_SQR0(v[4]);
 162         u[7] = gf2m_SQR1(v[3]);
 163         u[6] = gf2m_SQR0(v[3]);
 164 #endif
 165         u[5] = gf2m_SQR1(v[2]);
 166         u[4] = gf2m_SQR0(v[2]);
 167         u[3] = gf2m_SQR1(v[1]);
 168         u[2] = gf2m_SQR0(v[1]);
 169         u[1] = gf2m_SQR1(v[0]);
 170         u[0] = gf2m_SQR0(v[0]);
 171         return ec_GF2m_163_mod(r, r, meth);
 172
 173   CLEANUP:
 174         return res;
 175 }
 176
 177 /* Fast multiplication for polynomials over a 163-bit curve. Assumes
 178  * reduction polynomial with terms {163, 7, 6, 3, 0}. */
 179 mp_err
 180 ec_GF2m_163_mul(const mp_int *a, const mp_int *b, mp_int *r,
 181                                 const GFMethod *meth)
 182 {
 183         mp_err res = MP_OKAY;
 184         mp_digit a2 = 0, a1 = 0, a0, b2 = 0, b1 = 0, b0;
 185
 186 #ifdef ECL_THIRTY_TWO_BIT
 187         mp_digit a5 = 0, a4 = 0, a3 = 0, b5 = 0, b4 = 0, b3 = 0;
 188         mp_digit rm[6];
 189 #endif
 190
 191         if (a == b) {
 192                 return ec_GF2m_163_sqr(a, r, meth);
 193         } else {
 194                 switch (MP_USED(a)) {
 195 #ifdef ECL_THIRTY_TWO_BIT
 196                 case 6:
 197                         a5 = MP_DIGIT(a, 5);
 198                         /* FALLTHROUGH */
 199                 case 5:
 200                         a4 = MP_DIGIT(a, 4);
 201                         /* FALLTHROUGH */
 202                 case 4:
 203                         a3 = MP_DIGIT(a, 3);
 204 #endif
 205                         /* FALLTHROUGH */
 206                 case 3:
 207                         a2 = MP_DIGIT(a, 2);
 208                         /* FALLTHROUGH */
 209                 case 2:
 210                         a1 = MP_DIGIT(a, 1);
 211                         /* FALLTHROUGH */
 212                 default:
 213                         a0 = MP_DIGIT(a, 0);
 214                 }
 215                 switch (MP_USED(b)) {
 216 #ifdef ECL_THIRTY_TWO_BIT
 217                 case 6:
 218                         b5 = MP_DIGIT(b, 5);
 219                         /* FALLTHROUGH */
 220                 case 5:
 221                         b4 = MP_DIGIT(b, 4);
 222                         /* FALLTHROUGH */
 223                 case 4:
 224                         b3 = MP_DIGIT(b, 3);
 225 #endif
 226                         /* FALLTHROUGH */
 227                 case 3:
 228                         b2 = MP_DIGIT(b, 2);
 229                         /* FALLTHROUGH */
 230                 case 2:
 231                         b1 = MP_DIGIT(b, 1);
 232                         /* FALLTHROUGH */
 233                 default:
 234                         b0 = MP_DIGIT(b, 0);
 235                 }
 236 #ifdef ECL_SIXTY_FOUR_BIT
 237                 MP_CHECKOK(s_mp_pad(r, 6));
 238                 s_bmul_3x3(MP_DIGITS(r), a2, a1, a0, b2, b1, b0);
 239                 MP_USED(r) = 6;
 240                 s_mp_clamp(r);
 241 #else
 242                 MP_CHECKOK(s_mp_pad(r, 12));
 243                 s_bmul_3x3(MP_DIGITS(r) + 6, a5, a4, a3, b5, b4, b3);
 244                 s_bmul_3x3(MP_DIGITS(r), a2, a1, a0, b2, b1, b0);
 245                 s_bmul_3x3(rm, a5 ^ a2, a4 ^ a1, a3 ^ a0, b5 ^ b2, b4 ^ b1,
 246                                    b3 ^ b0);
 247                 rm[5] ^= MP_DIGIT(r, 5) ^ MP_DIGIT(r, 11);
 248                 rm[4] ^= MP_DIGIT(r, 4) ^ MP_DIGIT(r, 10);
 249                 rm[3] ^= MP_DIGIT(r, 3) ^ MP_DIGIT(r, 9);
 250                 rm[2] ^= MP_DIGIT(r, 2) ^ MP_DIGIT(r, 8);
 251                 rm[1] ^= MP_DIGIT(r, 1) ^ MP_DIGIT(r, 7);
 252                 rm[0] ^= MP_DIGIT(r, 0) ^ MP_DIGIT(r, 6);
 253                 MP_DIGIT(r, 8) ^= rm[5];
 254                 MP_DIGIT(r, 7) ^= rm[4];
 255                 MP_DIGIT(r, 6) ^= rm[3];
 256                 MP_DIGIT(r, 5) ^= rm[2];
 257                 MP_DIGIT(r, 4) ^= rm[1];
 258                 MP_DIGIT(r, 3) ^= rm[0];
 259                 MP_USED(r) = 12;
 260                 s_mp_clamp(r);
 261 #endif
 262                 return ec_GF2m_163_mod(r, r, meth);
 263         }
 264
 265   CLEANUP:
 266         return res;
 267 }
 268
 269 /* Wire in fast field arithmetic for 163-bit curves. */
 270 mp_err
 271 ec_group_set_gf2m163(ECGroup *group, ECCurveName name)
 272 {
 273         group->meth->field_mod = &ec_GF2m_163_mod;
 274         group->meth->field_mul = &ec_GF2m_163_mul;
 275         group->meth->field_sqr = &ec_GF2m_163_sqr;
 276         return MP_OKAY;
 277 }