release/src/router/openssl/crypto/bn/bn_x931p.c

   1 /* bn_x931p.c */
   2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   3  * project 2005.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2005 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59 #include <stdio.h>
  60 #include <openssl/bn.h>
  61
  62 /* X9.31 routines for prime derivation */
  63
  64 /* X9.31 prime derivation. This is used to generate the primes pi
  65  * (p1, p2, q1, q2) from a parameter Xpi by checking successive odd
  66  * integers.
  67  */
  68
  69 static int bn_x931_derive_pi(BIGNUM *pi, const BIGNUM *Xpi, BN_CTX *ctx,
  70                         BN_GENCB *cb)
  71         {
  72         int i = 0;
  73         if (!BN_copy(pi, Xpi))
  74                 return 0;
  75         if (!BN_is_odd(pi) && !BN_add_word(pi, 1))
  76                 return 0;
  77         for(;;)
  78                 {
  79                 i++;
  80                 BN_GENCB_call(cb, 0, i);
  81                 /* NB 27 MR is specificed in X9.31 */
  82                 if (BN_is_prime_fasttest_ex(pi, 27, ctx, 1, cb))
  83                         break;
  84                 if (!BN_add_word(pi, 2))
  85                         return 0;
  86                 }
  87         BN_GENCB_call(cb, 2, i);
  88         return 1;
  89         }
  90
  91 /* This is the main X9.31 prime derivation function. From parameters
  92  * Xp1, Xp2 and Xp derive the prime p. If the parameters p1 or p2 are
  93  * not NULL they will be returned too: this is needed for testing.
  94  */
  95
  96 int BN_X931_derive_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2,
  97                         const BIGNUM *Xp, const BIGNUM *Xp1, const BIGNUM *Xp2,
  98                         const BIGNUM *e, BN_CTX *ctx, BN_GENCB *cb)
  99         {
 100         int ret = 0;
 101
 102         BIGNUM *t, *p1p2, *pm1;
 103
 104         /* Only even e supported */
 105         if (!BN_is_odd(e))
 106                 return 0;
 107
 108         BN_CTX_start(ctx);
 109         if (!p1)
 110                 p1 = BN_CTX_get(ctx);
 111
 112         if (!p2)
 113                 p2 = BN_CTX_get(ctx);
 114
 115         t = BN_CTX_get(ctx);
 116
 117         p1p2 = BN_CTX_get(ctx);
 118
 119         pm1 = BN_CTX_get(ctx);
 120
 121         if (!bn_x931_derive_pi(p1, Xp1, ctx, cb))
 122                 goto err;
 123
 124         if (!bn_x931_derive_pi(p2, Xp2, ctx, cb))
 125                 goto err;
 126
 127         if (!BN_mul(p1p2, p1, p2, ctx))
 128                 goto err;
 129
 130         /* First set p to value of Rp */
 131
 132         if (!BN_mod_inverse(p, p2, p1, ctx))
 133                 goto err;
 134
 135         if (!BN_mul(p, p, p2, ctx))
 136                 goto err;
 137
 138         if (!BN_mod_inverse(t, p1, p2, ctx))
 139                 goto err;
 140
 141         if (!BN_mul(t, t, p1, ctx))
 142                 goto err;
 143
 144         if (!BN_sub(p, p, t))
 145                 goto err;
 146
 147         if (p->neg && !BN_add(p, p, p1p2))
 148                 goto err;
 149
 150         /* p now equals Rp */
 151
 152         if (!BN_mod_sub(p, p, Xp, p1p2, ctx))
 153                 goto err;
 154
 155         if (!BN_add(p, p, Xp))
 156                 goto err;
 157
 158         /* p now equals Yp0 */
 159
 160         for (;;)
 161                 {
 162                 int i = 1;
 163                 BN_GENCB_call(cb, 0, i++);
 164                 if (!BN_copy(pm1, p))
 165                         goto err;
 166                 if (!BN_sub_word(pm1, 1))
 167                         goto err;
 168                 if (!BN_gcd(t, pm1, e, ctx))
 169                         goto err;
 170                 if (BN_is_one(t)
 171                 /* X9.31 specifies 8 MR and 1 Lucas test or any prime test
 172                  * offering similar or better guarantees 50 MR is considerably
 173                  * better.
 174                  */
 175                         && BN_is_prime_fasttest_ex(p, 50, ctx, 1, cb))
 176                         break;
 177                 if (!BN_add(p, p, p1p2))
 178                         goto err;
 179                 }
 180
 181         BN_GENCB_call(cb, 3, 0);
 182
 183         ret = 1;
 184
 185         err:
 186
 187         BN_CTX_end(ctx);
 188
 189         return ret;
 190         }
 191
 192 /* Generate pair of paramters Xp, Xq for X9.31 prime generation.
 193  * Note: nbits paramter is sum of number of bits in both.
 194  */
 195
 196 int BN_X931_generate_Xpq(BIGNUM *Xp, BIGNUM *Xq, int nbits, BN_CTX *ctx)
 197         {
 198         BIGNUM *t;
 199         int i;
 200         /* Number of bits for each prime is of the form
 201          * 512+128s for s = 0, 1, ...
 202          */
 203         if ((nbits < 1024) || (nbits & 0xff))
 204                 return 0;
 205         nbits >>= 1;
 206         /* The random value Xp must be between sqrt(2) * 2^(nbits-1) and
 207          * 2^nbits - 1. By setting the top two bits we ensure that the lower
 208          * bound is exceeded.
 209          */
 210         if (!BN_rand(Xp, nbits, 1, 0))
 211                 return 0;
 212
 213         BN_CTX_start(ctx);
 214         t = BN_CTX_get(ctx);
 215
 216         for (i = 0; i < 1000; i++)
 217                 {
 218                 if (!BN_rand(Xq, nbits, 1, 0))
 219                         return 0;
 220                 /* Check that |Xp - Xq| > 2^(nbits - 100) */
 221                 BN_sub(t, Xp, Xq);
 222                 if (BN_num_bits(t) > (nbits - 100))
 223                         break;
 224                 }
 225
 226         BN_CTX_end(ctx);
 227
 228         if (i < 1000)
 229                 return 1;
 230
 231         return 0;
 232
 233         }
 234
 235 /* Generate primes using X9.31 algorithm. Of the values p, p1, p2, Xp1
 236  * and Xp2 only 'p' needs to be non-NULL. If any of the others are not NULL
 237  * the relevant parameter will be stored in it.
 238  *
 239  * Due to the fact that |Xp - Xq| > 2^(nbits - 100) must be satisfied Xp and Xq
 240  * are generated using the previous function and supplied as input.
 241  */
 242
 243 int BN_X931_generate_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2,
 244                         BIGNUM *Xp1, BIGNUM *Xp2,
 245                         const BIGNUM *Xp,
 246                         const BIGNUM *e, BN_CTX *ctx,
 247                         BN_GENCB *cb)
 248         {
 249         int ret = 0;
 250
 251         BN_CTX_start(ctx);
 252         if (!Xp1)
 253                 Xp1 = BN_CTX_get(ctx);
 254         if (!Xp2)
 255                 Xp2 = BN_CTX_get(ctx);
 256
 257         if (!BN_rand(Xp1, 101, 0, 0))
 258                 goto error;
 259         if (!BN_rand(Xp2, 101, 0, 0))
 260                 goto error;
 261         if (!BN_X931_derive_prime_ex(p, p1, p2, Xp, Xp1, Xp2, e, ctx, cb))
 262                 goto error;
 263
 264         ret = 1;
 265
 266         error:
 267         BN_CTX_end(ctx);
 268
 269         return ret;
 270
 271         }
 272