crypto/bn/bn_blind.c

   1 /* crypto/bn/bn_blind.c */
   2 /* ====================================================================
   3  * Copyright (c) 1998-2006 The OpenSSL Project.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in
  14  *    the documentation and/or other materials provided with the
  15  *    distribution.
  16  *
  17  * 3. All advertising materials mentioning features or use of this
  18  *    software must display the following acknowledgment:
  19  *    "This product includes software developed by the OpenSSL Project
  20  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  21  *
  22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  23  *    endorse or promote products derived from this software without
  24  *    prior written permission. For written permission, please contact
  25  *    openssl-core@openssl.org.
  26  *
  27  * 5. Products derived from this software may not be called "OpenSSL"
  28  *    nor may "OpenSSL" appear in their names without prior written
  29  *    permission of the OpenSSL Project.
  30  *
  31  * 6. Redistributions of any form whatsoever must retain the following
  32  *    acknowledgment:
  33  *    "This product includes software developed by the OpenSSL Project
  34  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  47  * OF THE POSSIBILITY OF SUCH DAMAGE.
  48  * ====================================================================
  49  *
  50  * This product includes cryptographic software written by Eric Young
  51  * (eay@cryptsoft.com).  This product includes software written by Tim
  52  * Hudson (tjh@cryptsoft.com).
  53  *
  54  */
  55 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  56  * All rights reserved.
  57  *
  58  * This package is an SSL implementation written
  59  * by Eric Young (eay@cryptsoft.com).
  60  * The implementation was written so as to conform with Netscapes SSL.
  61  *
  62  * This library is free for commercial and non-commercial use as long as
  63  * the following conditions are aheared to.  The following conditions
  64  * apply to all code found in this distribution, be it the RC4, RSA,
  65  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  66  * included with this distribution is covered by the same copyright terms
  67  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  68  *
  69  * Copyright remains Eric Young's, and as such any Copyright notices in
  70  * the code are not to be removed.
  71  * If this package is used in a product, Eric Young should be given attribution
  72  * as the author of the parts of the library used.
  73  * This can be in the form of a textual message at program startup or
  74  * in documentation (online or textual) provided with the package.
  75  *
  76  * Redistribution and use in source and binary forms, with or without
  77  * modification, are permitted provided that the following conditions
  78  * are met:
  79  * 1. Redistributions of source code must retain the copyright
  80  *    notice, this list of conditions and the following disclaimer.
  81  * 2. Redistributions in binary form must reproduce the above copyright
  82  *    notice, this list of conditions and the following disclaimer in the
  83  *    documentation and/or other materials provided with the distribution.
  84  * 3. All advertising materials mentioning features or use of this software
  85  *    must display the following acknowledgement:
  86  *    "This product includes cryptographic software written by
  87  *     Eric Young (eay@cryptsoft.com)"
  88  *    The word 'cryptographic' can be left out if the rouines from the library
  89  *    being used are not cryptographic related :-).
  90  * 4. If you include any Windows specific code (or a derivative thereof) from
  91  *    the apps directory (application code) you must include an acknowledgement:
  92  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  93  *
  94  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  95  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  96  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  97  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  98  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  99  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 100  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 101  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 102  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 103  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 104  * SUCH DAMAGE.
 105  *
 106  * The licence and distribution terms for any publically available version or
 107  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 108  * copied and put under another distribution licence
 109  * [including the GNU Public Licence.]
 110  */
 111
 112 #include <stdio.h>
 113 #include "cryptlib.h"
 114 #include "bn_lcl.h"
 115
 116 #define BN_BLINDING_COUNTER     32
 117
 118 struct bn_blinding_st
 119         {
 120         BIGNUM *A;
 121         BIGNUM *Ai;
 122         BIGNUM *e;
 123         BIGNUM *mod; /* just a reference */
 124 #ifndef OPENSSL_NO_DEPRECATED
 125         unsigned long thread_id; /* added in OpenSSL 0.9.6j and 0.9.7b;
 126                                   * used only by crypto/rsa/rsa_eay.c, rsa_lib.c */
 127 #endif
 128         CRYPTO_THREADID tid;
 129         unsigned int  counter;
 130         unsigned long flags;
 131         BN_MONT_CTX *m_ctx;
 132         int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
 133                           const BIGNUM *m, BN_CTX *ctx,
 134                           BN_MONT_CTX *m_ctx);
 135         };
 136
 137 BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod)
 138         {
 139         BN_BLINDING *ret=NULL;
 140
 141         bn_check_top(mod);
 142
 143         if ((ret=(BN_BLINDING *)OPENSSL_malloc(sizeof(BN_BLINDING))) == NULL)
 144                 {
 145                 BNerr(BN_F_BN_BLINDING_NEW,ERR_R_MALLOC_FAILURE);
 146                 return(NULL);
 147                 }
 148         memset(ret,0,sizeof(BN_BLINDING));
 149         if (A != NULL)
 150                 {
 151                 if ((ret->A  = BN_dup(A))  == NULL) goto err;
 152                 }
 153         if (Ai != NULL)
 154                 {
 155                 if ((ret->Ai = BN_dup(Ai)) == NULL) goto err;
 156                 }
 157
 158         /* save a copy of mod in the BN_BLINDING structure */
 159         if ((ret->mod = BN_dup(mod)) == NULL) goto err;
 160         if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)
 161                 BN_set_flags(ret->mod, BN_FLG_CONSTTIME);
 162
 163         ret->counter = BN_BLINDING_COUNTER;
 164         CRYPTO_THREADID_current(&ret->tid);
 165         return(ret);
 166 err:
 167         if (ret != NULL) BN_BLINDING_free(ret);
 168         return(NULL);
 169         }
 170
 171 void BN_BLINDING_free(BN_BLINDING *r)
 172         {
 173         if(r == NULL)
 174             return;
 175
 176         if (r->A  != NULL) BN_free(r->A );
 177         if (r->Ai != NULL) BN_free(r->Ai);
 178         if (r->e  != NULL) BN_free(r->e );
 179         if (r->mod != NULL) BN_free(r->mod);
 180         OPENSSL_free(r);
 181         }
 182
 183 int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx)
 184         {
 185         int ret=0;
 186
 187         if ((b->A == NULL) || (b->Ai == NULL))
 188                 {
 189                 BNerr(BN_F_BN_BLINDING_UPDATE,BN_R_NOT_INITIALIZED);
 190                 goto err;
 191                 }
 192
 193         if (--(b->counter) == 0 && b->e != NULL &&
 194                 !(b->flags & BN_BLINDING_NO_RECREATE))
 195                 {
 196                 /* re-create blinding parameters */
 197                 if (!BN_BLINDING_create_param(b, NULL, NULL, ctx, NULL, NULL))
 198                         goto err;
 199                 }
 200         else if (!(b->flags & BN_BLINDING_NO_UPDATE))
 201                 {
 202                 if (!BN_mod_mul(b->A,b->A,b->A,b->mod,ctx)) goto err;
 203                 if (!BN_mod_mul(b->Ai,b->Ai,b->Ai,b->mod,ctx)) goto err;
 204                 }
 205
 206         ret=1;
 207 err:
 208         if (b->counter == 0)
 209                 b->counter = BN_BLINDING_COUNTER;
 210         return(ret);
 211         }
 212
 213 int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
 214         {
 215         return BN_BLINDING_convert_ex(n, NULL, b, ctx);
 216         }
 217
 218 int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
 219         {
 220         int ret = 1;
 221
 222         bn_check_top(n);
 223
 224         if ((b->A == NULL) || (b->Ai == NULL))
 225                 {
 226                 BNerr(BN_F_BN_BLINDING_CONVERT_EX,BN_R_NOT_INITIALIZED);
 227                 return(0);
 228                 }
 229
 230         if (r != NULL)
 231                 {
 232                 if (!BN_copy(r, b->Ai)) ret=0;
 233                 }
 234
 235         if (!BN_mod_mul(n,n,b->A,b->mod,ctx)) ret=0;
 236
 237         return ret;
 238         }
 239
 240 int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
 241         {
 242         return BN_BLINDING_invert_ex(n, NULL, b, ctx);
 243         }
 244
 245 int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
 246         {
 247         int ret;
 248
 249         bn_check_top(n);
 250         if ((b->A == NULL) || (b->Ai == NULL))
 251                 {
 252                 BNerr(BN_F_BN_BLINDING_INVERT_EX,BN_R_NOT_INITIALIZED);
 253                 return(0);
 254                 }
 255
 256         if (r != NULL)
 257                 ret = BN_mod_mul(n, n, r, b->mod, ctx);
 258         else
 259                 ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx);
 260
 261         if (ret >= 0)
 262                 {
 263                 if (!BN_BLINDING_update(b,ctx))
 264                         return(0);
 265                 }
 266         bn_check_top(n);
 267         return(ret);
 268         }
 269
 270 #ifndef OPENSSL_NO_DEPRECATED
 271 unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *b)
 272         {
 273         return b->thread_id;
 274         }
 275
 276 void BN_BLINDING_set_thread_id(BN_BLINDING *b, unsigned long n)
 277         {
 278         b->thread_id = n;
 279         }
 280 #endif
 281
 282 CRYPTO_THREADID *BN_BLINDING_thread_id(BN_BLINDING *b)
 283         {
 284         return &b->tid;
 285         }
 286
 287 unsigned long BN_BLINDING_get_flags(const BN_BLINDING *b)
 288         {
 289         return b->flags;
 290         }
 291
 292 void BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags)
 293         {
 294         b->flags = flags;
 295         }
 296
 297 BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
 298         const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
 299         int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
 300                           const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),
 301         BN_MONT_CTX *m_ctx)
 302 {
 303         int    retry_counter = 32;
 304         BN_BLINDING *ret = NULL;
 305
 306         if (b == NULL)
 307                 ret = BN_BLINDING_new(NULL, NULL, m);
 308         else
 309                 ret = b;
 310
 311         if (ret == NULL)
 312                 goto err;
 313
 314         if (ret->A  == NULL && (ret->A  = BN_new()) == NULL)
 315                 goto err;
 316         if (ret->Ai == NULL && (ret->Ai = BN_new()) == NULL)
 317                 goto err;
 318
 319         if (e != NULL)
 320                 {
 321                 if (ret->e != NULL)
 322                         BN_free(ret->e);
 323                 ret->e = BN_dup(e);
 324                 }
 325         if (ret->e == NULL)
 326                 goto err;
 327
 328         if (bn_mod_exp != NULL)
 329                 ret->bn_mod_exp = bn_mod_exp;
 330         if (m_ctx != NULL)
 331                 ret->m_ctx = m_ctx;
 332
 333         do {
 334                 int rv;
 335                 if (!BN_rand_range(ret->A, ret->mod)) goto err;
 336                 if (!int_bn_mod_inverse(ret->Ai, ret->A, ret->mod, ctx, &rv))
 337                         {
 338                         /* this should almost never happen for good RSA keys */
 339                         if (rv)
 340                                 {
 341                                 if (retry_counter-- == 0)
 342                                 {
 343                                         BNerr(BN_F_BN_BLINDING_CREATE_PARAM,
 344                                                 BN_R_TOO_MANY_ITERATIONS);
 345                                         goto err;
 346                                 }
 347                                 }
 348                         else
 349                                 goto err;
 350                         }
 351                 else
 352                         break;
 353         } while (1);
 354
 355         if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL)
 356                 {
 357                 if (!ret->bn_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx, ret->m_ctx))
 358                         goto err;
 359                 }
 360         else
 361                 {
 362                 if (!BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx))
 363                         goto err;
 364                 }
 365
 366         return ret;
 367 err:
 368         if (b == NULL && ret != NULL)
 369                 {
 370                 BN_BLINDING_free(ret);
 371                 ret = NULL;
 372                 }
 373
 374         return ret;
 375 }