1 /* crypto/bn/bn_blind.c */

     2 /* ====================================================================

     3  * Copyright (c) 1998-2005 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 	unsigned long thread_id; /* added in OpenSSL 0.9.6j and 0.9.7b;

   125 				  * used only by crypto/rsa/rsa_eay.c, rsa_lib.c */

   126 	unsigned int  counter;

   127 	unsigned long flags;

   128 	BN_MONT_CTX *m_ctx;

   129 	int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,

   130 			  const BIGNUM *m, BN_CTX *ctx,

   131 			  BN_MONT_CTX *m_ctx);

   132 	};

   133 

   134 EXPORT_C BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod)

   135 	{

   136 	BN_BLINDING *ret=NULL;

   137 

   138 	bn_check_top(mod);

   139 

   140 	if ((ret=(BN_BLINDING *)OPENSSL_malloc(sizeof(BN_BLINDING))) == NULL)

   141 		{

   142 		BNerr(BN_F_BN_BLINDING_NEW,ERR_R_MALLOC_FAILURE);

   143 		return(NULL);

   144 		}

   145 	memset(ret,0,sizeof(BN_BLINDING));

   146 	if (A != NULL)

   147 		{

   148 		if ((ret->A  = BN_dup(A))  == NULL) goto err;

   149 		}

   150 	if (Ai != NULL)

   151 		{

   152 		if ((ret->Ai = BN_dup(Ai)) == NULL) goto err;

   153 		}

   154 	ret->mod = mod;

   155 	/* save a copy of mod in the BN_BLINDING structure */

   156 	if ((ret->mod = BN_dup(mod)) == NULL) goto err;

   157 	if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)

   158 		BN_set_flags(ret->mod, BN_FLG_CONSTTIME);

   159 	ret->counter = BN_BLINDING_COUNTER;

   160 	return(ret);

   161 err:

   162 	if (ret != NULL) BN_BLINDING_free(ret);

   163 	return(NULL);

   164 	}

   165 

   166 EXPORT_C void BN_BLINDING_free(BN_BLINDING *r)

   167 	{

   168 	if(r == NULL)

   169 	    return;

   170 

   171 	if (r->A  != NULL) BN_free(r->A );

   172 	if (r->Ai != NULL) BN_free(r->Ai);

   173 	if (r->e  != NULL) BN_free(r->e );

   174 	if (r->mod != NULL) BN_free(r->mod); 

   175 	OPENSSL_free(r);

   176 	}

   177 

   178 EXPORT_C int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx)

   179 	{

   180 	int ret=0;

   181 

   182 	if ((b->A == NULL) || (b->Ai == NULL))

   183 		{

   184 		BNerr(BN_F_BN_BLINDING_UPDATE,BN_R_NOT_INITIALIZED);

   185 		goto err;

   186 		}

   187 

   188 	if (--(b->counter) == 0 && b->e != NULL &&

   189 		!(b->flags & BN_BLINDING_NO_RECREATE))

   190 		{

   191 		/* re-create blinding parameters */

   192 		if (!BN_BLINDING_create_param(b, NULL, NULL, ctx, NULL, NULL))

   193 			goto err;

   194 		}

   195 	else if (!(b->flags & BN_BLINDING_NO_UPDATE))

   196 		{

   197 		if (!BN_mod_mul(b->A,b->A,b->A,b->mod,ctx)) goto err;

   198 		if (!BN_mod_mul(b->Ai,b->Ai,b->Ai,b->mod,ctx)) goto err;

   199 		}

   200 

   201 	ret=1;

   202 err:

   203 	if (b->counter == 0)

   204 		b->counter = BN_BLINDING_COUNTER;

   205 	return(ret);

   206 	}

   207 

   208 EXPORT_C int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)

   209 	{

   210 	return BN_BLINDING_convert_ex(n, NULL, b, ctx);

   211 	}

   212 

   213 EXPORT_C int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)

   214 	{

   215 	int ret = 1;

   216 

   217 	bn_check_top(n);

   218 

   219 	if ((b->A == NULL) || (b->Ai == NULL))

   220 		{

   221 		BNerr(BN_F_BN_BLINDING_CONVERT_EX,BN_R_NOT_INITIALIZED);

   222 		return(0);

   223 		}

   224 

   225 	if (r != NULL)

   226 		{

   227 		if (!BN_copy(r, b->Ai)) ret=0;

   228 		}

   229 

   230 	if (!BN_mod_mul(n,n,b->A,b->mod,ctx)) ret=0;

   231 	

   232 	return ret;

   233 	}

   234 

   235 EXPORT_C int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)

   236 	{

   237 	return BN_BLINDING_invert_ex(n, NULL, b, ctx);

   238 	}

   239 

   240 EXPORT_C int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)

   241 	{

   242 	int ret;

   243 

   244 	bn_check_top(n);

   245 	if ((b->A == NULL) || (b->Ai == NULL))

   246 		{

   247 		BNerr(BN_F_BN_BLINDING_INVERT_EX,BN_R_NOT_INITIALIZED);

   248 		return(0);

   249 		}

   250 

   251 	if (r != NULL)

   252 		ret = BN_mod_mul(n, n, r, b->mod, ctx);

   253 	else

   254 		ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx);

   255 

   256 	if (ret >= 0)

   257 		{

   258 		if (!BN_BLINDING_update(b,ctx))

   259 			return(0);

   260 		}

   261 	bn_check_top(n);

   262 	return(ret);

   263 	}

   264 

   265 EXPORT_C unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *b)

   266 	{

   267 	return b->thread_id;

   268 	}

   269 

   270 EXPORT_C void BN_BLINDING_set_thread_id(BN_BLINDING *b, unsigned long n)

   271 	{

   272 	b->thread_id = n;

   273 	}

   274 

   275 EXPORT_C unsigned long BN_BLINDING_get_flags(const BN_BLINDING *b)

   276 	{

   277 	return b->flags;

   278 	}

   279 

   280 EXPORT_C void BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags)

   281 	{

   282 	b->flags = flags;

   283 	}

   284 

   285 EXPORT_C BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,

   286 	const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,

   287 	int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,

   288 			  const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),

   289 	BN_MONT_CTX *m_ctx)

   290 {

   291 	int    retry_counter = 32;

   292 	BN_BLINDING *ret = NULL;

   293 

   294 	if (b == NULL)

   295 		ret = BN_BLINDING_new(NULL, NULL, m);

   296 	else

   297 		ret = b;

   298 

   299 	if (ret == NULL)

   300 		goto err;

   301 

   302 	if (ret->A  == NULL && (ret->A  = BN_new()) == NULL)

   303 		goto err;

   304 	if (ret->Ai == NULL && (ret->Ai	= BN_new()) == NULL)

   305 		goto err;

   306 

   307 	if (e != NULL)

   308 		{

   309 		if (ret->e != NULL)

   310 			BN_free(ret->e);

   311 		ret->e = BN_dup(e);

   312 		}

   313 	if (ret->e == NULL)

   314 		goto err;

   315 

   316 	if (bn_mod_exp != NULL)

   317 		ret->bn_mod_exp = bn_mod_exp;

   318 	if (m_ctx != NULL)

   319 		ret->m_ctx = m_ctx;

   320 

   321 	do {

   322 		if (!BN_rand_range(ret->A, ret->mod)) goto err;

   323 		if (BN_mod_inverse(ret->Ai, ret->A, ret->mod, ctx) == NULL)

   324 			{

   325 			/* this should almost never happen for good RSA keys */

   326 			unsigned long error = ERR_peek_last_error();

   327 			if (ERR_GET_REASON(error) == BN_R_NO_INVERSE)

   328 				{

   329 				if (retry_counter-- == 0)

   330 				{

   331 					BNerr(BN_F_BN_BLINDING_CREATE_PARAM,

   332 						BN_R_TOO_MANY_ITERATIONS);

   333 					goto err;

   334 				}

   335 				ERR_clear_error();

   336 				}

   337 			else

   338 				goto err;

   339 			}

   340 		else

   341 			break;

   342 	} while (1);

   343 

   344 	if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL)

   345 		{

   346 		if (!ret->bn_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx, ret->m_ctx))

   347 			goto err;

   348 		}

   349 	else

   350 		{

   351 		if (!BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx))

   352 			goto err;

   353 		}

   354 

   355 	return ret;

   356 err:

   357 	if (b == NULL && ret != NULL)

   358 		{

   359 		BN_BLINDING_free(ret);

   360 		ret = NULL;

   361 		}

   362 

   363 	return ret;

   364 }