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 #define OPENSSL_FIPSAPI
 113
 114 #include <stdio.h>
 115 #include "cryptlib.h"
 116 #include "bn_lcl.h"
 117
 118 #define BN_BLINDING_COUNTER     32
 119
 120 struct bn_blinding_st
 121         {
 122         BIGNUM *A;
 123         BIGNUM *Ai;
 124         BIGNUM *e;
 125         BIGNUM *mod; /* just a reference */
 126 #ifndef OPENSSL_NO_DEPRECATED
 127         unsigned long thread_id; /* added in OpenSSL 0.9.6j and 0.9.7b;
 128                                   * used only by crypto/rsa/rsa_eay.c, rsa_lib.c */
 129 #endif
 130         CRYPTO_THREADID tid;
 131         int counter;
 132         unsigned long flags;
 133         BN_MONT_CTX *m_ctx;
 134         int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
 135                           const BIGNUM *m, BN_CTX *ctx,
 136                           BN_MONT_CTX *m_ctx);
 137         };
 138
 139 BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod)
 140         {
 141         BN_BLINDING *ret=NULL;
 142
 143         bn_check_top(mod);
 144
 145         if ((ret=(BN_BLINDING *)OPENSSL_malloc(sizeof(BN_BLINDING))) == NULL)
 146                 {
 147                 BNerr(BN_F_BN_BLINDING_NEW,ERR_R_MALLOC_FAILURE);
 148                 return(NULL);
 149                 }
 150         memset(ret,0,sizeof(BN_BLINDING));
 151         if (A != NULL)
 152                 {
 153                 if ((ret->A  = BN_dup(A))  == NULL) goto err;
 154                 }
 155         if (Ai != NULL)
 156                 {
 157                 if ((ret->Ai = BN_dup(Ai)) == NULL) goto err;
 158                 }
 159
 160         /* save a copy of mod in the BN_BLINDING structure */
 161         if ((ret->mod = BN_dup(mod)) == NULL) goto err;
 162         if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)
 163                 BN_set_flags(ret->mod, BN_FLG_CONSTTIME);
 164
 165         /* Set the counter to the special value -1
 166          * to indicate that this is never-used fresh blinding
 167          * that does not need updating before first use. */
 168         ret->counter = -1;
 169         CRYPTO_THREADID_current(&ret->tid);
 170         return(ret);
 171 err:
 172         if (ret != NULL) BN_BLINDING_free(ret);
 173         return(NULL);
 174         }
 175
 176 void BN_BLINDING_free(BN_BLINDING *r)
 177         {
 178         if(r == NULL)
 179             return;
 180
 181         if (r->A  != NULL) BN_free(r->A );
 182         if (r->Ai != NULL) BN_free(r->Ai);
 183         if (r->e  != NULL) BN_free(r->e );
 184         if (r->mod != NULL) BN_free(r->mod);
 185         OPENSSL_free(r);
 186         }
 187
 188 int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx)
 189         {
 190         int ret=0;
 191
 192         if ((b->A == NULL) || (b->Ai == NULL))
 193                 {
 194                 BNerr(BN_F_BN_BLINDING_UPDATE,BN_R_NOT_INITIALIZED);
 195                 goto err;
 196                 }
 197
 198         if (b->counter == -1)
 199                 b->counter = 0;
 200
 201         if (++b->counter == BN_BLINDING_COUNTER && b->e != NULL &&
 202                 !(b->flags & BN_BLINDING_NO_RECREATE))
 203                 {
 204                 /* re-create blinding parameters */
 205                 if (!BN_BLINDING_create_param(b, NULL, NULL, ctx, NULL, NULL))
 206                         goto err;
 207                 }
 208         else if (!(b->flags & BN_BLINDING_NO_UPDATE))
 209                 {
 210                 if (!BN_mod_mul(b->A,b->A,b->A,b->mod,ctx)) goto err;
 211                 if (!BN_mod_mul(b->Ai,b->Ai,b->Ai,b->mod,ctx)) goto err;
 212                 }
 213
 214         ret=1;
 215 err:
 216         if (b->counter == BN_BLINDING_COUNTER)
 217                 b->counter = 0;
 218         return(ret);
 219         }
 220
 221 int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
 222         {
 223         return BN_BLINDING_convert_ex(n, NULL, b, ctx);
 224         }
 225
 226 int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
 227         {
 228         int ret = 1;
 229
 230         bn_check_top(n);
 231
 232         if ((b->A == NULL) || (b->Ai == NULL))
 233                 {
 234                 BNerr(BN_F_BN_BLINDING_CONVERT_EX,BN_R_NOT_INITIALIZED);
 235                 return(0);
 236                 }
 237
 238         if (b->counter == -1)
 239                 /* Fresh blinding, doesn't need updating. */
 240                 b->counter = 0;
 241         else if (!BN_BLINDING_update(b,ctx))
 242                 return(0);
 243
 244         if (r != NULL)
 245                 {
 246                 if (!BN_copy(r, b->Ai)) ret=0;
 247                 }
 248
 249         if (!BN_mod_mul(n,n,b->A,b->mod,ctx)) ret=0;
 250
 251         return ret;
 252         }
 253
 254 int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
 255         {
 256         return BN_BLINDING_invert_ex(n, NULL, b, ctx);
 257         }
 258
 259 int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
 260         {
 261         int ret;
 262
 263         bn_check_top(n);
 264
 265         if (r != NULL)
 266                 ret = BN_mod_mul(n, n, r, b->mod, ctx);
 267         else
 268                 {
 269                 if (b->Ai == NULL)
 270                         {
 271                         BNerr(BN_F_BN_BLINDING_INVERT_EX,BN_R_NOT_INITIALIZED);
 272                         return(0);
 273                         }
 274                 ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx);
 275                 }
 276
 277         bn_check_top(n);
 278         return(ret);
 279         }
 280
 281 #ifndef OPENSSL_NO_DEPRECATED
 282 unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *b)
 283         {
 284         return b->thread_id;
 285         }
 286
 287 void BN_BLINDING_set_thread_id(BN_BLINDING *b, unsigned long n)
 288         {
 289         b->thread_id = n;
 290         }
 291 #endif
 292
 293 CRYPTO_THREADID *BN_BLINDING_thread_id(BN_BLINDING *b)
 294         {
 295         return &b->tid;
 296         }
 297
 298 unsigned long BN_BLINDING_get_flags(const BN_BLINDING *b)
 299         {
 300         return b->flags;
 301         }
 302
 303 void BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags)
 304         {
 305         b->flags = flags;
 306         }
 307
 308 BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
 309         const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
 310         int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
 311                           const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),
 312         BN_MONT_CTX *m_ctx)
 313 {
 314         int    retry_counter = 32;
 315         BN_BLINDING *ret = NULL;
 316
 317         if (b == NULL)
 318                 ret = BN_BLINDING_new(NULL, NULL, m);
 319         else
 320                 ret = b;
 321
 322         if (ret == NULL)
 323                 goto err;
 324
 325         if (ret->A  == NULL && (ret->A  = BN_new()) == NULL)
 326                 goto err;
 327         if (ret->Ai == NULL && (ret->Ai = BN_new()) == NULL)
 328                 goto err;
 329
 330         if (e != NULL)
 331                 {
 332                 if (ret->e != NULL)
 333                         BN_free(ret->e);
 334                 ret->e = BN_dup(e);
 335                 }
 336         if (ret->e == NULL)
 337                 goto err;
 338
 339         if (bn_mod_exp != NULL)
 340                 ret->bn_mod_exp = bn_mod_exp;
 341         if (m_ctx != NULL)
 342                 ret->m_ctx = m_ctx;
 343
 344         do {
 345                 int rv;
 346                 if (!BN_rand_range(ret->A, ret->mod)) goto err;
 347                 if (!int_bn_mod_inverse(ret->Ai, ret->A, ret->mod, ctx, &rv))
 348                         {
 349                         /* this should almost never happen for good RSA keys */
 350                         if (rv)
 351                                 {
 352                                 if (retry_counter-- == 0)
 353                                 {
 354                                         BNerr(BN_F_BN_BLINDING_CREATE_PARAM,
 355                                                 BN_R_TOO_MANY_ITERATIONS);
 356                                         goto err;
 357                                 }
 358                                 }
 359                         else
 360                                 goto err;
 361                         }
 362                 else
 363                         break;
 364         } while (1);
 365
 366         if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL)
 367                 {
 368                 if (!ret->bn_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx, ret->m_ctx))
 369                         goto err;
 370                 }
 371         else
 372                 {
 373                 if (!BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx))
 374                         goto err;
 375                 }
 376
 377         return ret;
 378 err:
 379         if (b == NULL && ret != NULL)
 380                 {
 381                 BN_BLINDING_free(ret);
 382                 ret = NULL;
 383                 }
 384
 385         return ret;
 386 }