bn_blind.c 11.2 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385
/* crypto/bn/bn_blind.c */
/* ====================================================================
 * Copyright (c) 1998-2006 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include "cryptlib.h"
#include "bn_lcl.h"

#define BN_BLINDING_COUNTER	32

struct bn_blinding_st
	{
	BIGNUM *A;
	BIGNUM *Ai;
	BIGNUM *e;
	BIGNUM *mod; /* just a reference */
#ifndef OPENSSL_NO_DEPRECATED
	unsigned long thread_id; /* added in OpenSSL 0.9.6j and 0.9.7b;
				  * used only by crypto/rsa/rsa_eay.c, rsa_lib.c */
#endif
	CRYPTO_THREADID tid;
	int counter;
	unsigned long flags;
	BN_MONT_CTX *m_ctx;
	int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
			  const BIGNUM *m, BN_CTX *ctx,
			  BN_MONT_CTX *m_ctx);
	};

BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod)
	{
	BN_BLINDING *ret=NULL;

	bn_check_top(mod);

	if ((ret=(BN_BLINDING *)OPENSSL_malloc(sizeof(BN_BLINDING))) == NULL)
		{
		BNerr(BN_F_BN_BLINDING_NEW,ERR_R_MALLOC_FAILURE);
		return(NULL);
		}
	memset(ret,0,sizeof(BN_BLINDING));
	if (A != NULL)
		{
		if ((ret->A  = BN_dup(A))  == NULL) goto err;
		}
	if (Ai != NULL)
		{
		if ((ret->Ai = BN_dup(Ai)) == NULL) goto err;
		}

	/* save a copy of mod in the BN_BLINDING structure */
	if ((ret->mod = BN_dup(mod)) == NULL) goto err;
	if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)
		BN_set_flags(ret->mod, BN_FLG_CONSTTIME);

	/* Set the counter to the special value -1
	 * to indicate that this is never-used fresh blinding
	 * that does not need updating before first use. */
	ret->counter = -1;
	CRYPTO_THREADID_current(&ret->tid);
	return(ret);
err:
	if (ret != NULL) BN_BLINDING_free(ret);
	return(NULL);
	}

void BN_BLINDING_free(BN_BLINDING *r)
	{
	if(r == NULL)
	    return;

	if (r->A  != NULL) BN_free(r->A );
	if (r->Ai != NULL) BN_free(r->Ai);
	if (r->e  != NULL) BN_free(r->e );
	if (r->mod != NULL) BN_free(r->mod); 
	OPENSSL_free(r);
	}

int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx)
	{
	int ret=0;

	if ((b->A == NULL) || (b->Ai == NULL))
		{
		BNerr(BN_F_BN_BLINDING_UPDATE,BN_R_NOT_INITIALIZED);
		goto err;
		}

	if (b->counter == -1)
		b->counter = 0;

	if (++b->counter == BN_BLINDING_COUNTER && b->e != NULL &&
		!(b->flags & BN_BLINDING_NO_RECREATE))
		{
		/* re-create blinding parameters */
		if (!BN_BLINDING_create_param(b, NULL, NULL, ctx, NULL, NULL))
			goto err;
		}
	else if (!(b->flags & BN_BLINDING_NO_UPDATE))
		{
		if (!BN_mod_mul(b->A,b->A,b->A,b->mod,ctx)) goto err;
		if (!BN_mod_mul(b->Ai,b->Ai,b->Ai,b->mod,ctx)) goto err;
		}

	ret=1;
err:
	if (b->counter == BN_BLINDING_COUNTER)
		b->counter = 0;
	return(ret);
	}

int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
	{
	return BN_BLINDING_convert_ex(n, NULL, b, ctx);
	}

int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
	{
	int ret = 1;

	bn_check_top(n);

	if ((b->A == NULL) || (b->Ai == NULL))
		{
		BNerr(BN_F_BN_BLINDING_CONVERT_EX,BN_R_NOT_INITIALIZED);
		return(0);
		}

	if (b->counter == -1)
		/* Fresh blinding, doesn't need updating. */
		b->counter = 0;
	else if (!BN_BLINDING_update(b,ctx))
		return(0);

	if (r != NULL)
		{
		if (!BN_copy(r, b->Ai)) ret=0;
		}

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

int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
	{
	return BN_BLINDING_invert_ex(n, NULL, b, ctx);
	}

int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
	{
	int ret;

	bn_check_top(n);

	if (r != NULL)
		ret = BN_mod_mul(n, n, r, b->mod, ctx);
	else
		{
		if (b->Ai == NULL)
			{
			BNerr(BN_F_BN_BLINDING_INVERT_EX,BN_R_NOT_INITIALIZED);
			return(0);
			}
		ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx);
		}

	bn_check_top(n);
	return(ret);
	}

#ifndef OPENSSL_NO_DEPRECATED
unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *b)
	{
	return b->thread_id;
	}

void BN_BLINDING_set_thread_id(BN_BLINDING *b, unsigned long n)
	{
	b->thread_id = n;
	}
#endif

CRYPTO_THREADID *BN_BLINDING_thread_id(BN_BLINDING *b)
	{
	return &b->tid;
	}

unsigned long BN_BLINDING_get_flags(const BN_BLINDING *b)
	{
	return b->flags;
	}

void BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags)
	{
	b->flags = flags;
	}

BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
	const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
	int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
			  const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),
	BN_MONT_CTX *m_ctx)
{
	int    retry_counter = 32;
	BN_BLINDING *ret = NULL;

	if (b == NULL)
		ret = BN_BLINDING_new(NULL, NULL, m);
	else
		ret = b;

	if (ret == NULL)
		goto err;

	if (ret->A  == NULL && (ret->A  = BN_new()) == NULL)
		goto err;
	if (ret->Ai == NULL && (ret->Ai	= BN_new()) == NULL)
		goto err;

	if (e != NULL)
		{
		if (ret->e != NULL)
			BN_free(ret->e);
		ret->e = BN_dup(e);
		}
	if (ret->e == NULL)
		goto err;

	if (bn_mod_exp != NULL)
		ret->bn_mod_exp = bn_mod_exp;
	if (m_ctx != NULL)
		ret->m_ctx = m_ctx;

	do {
		if (!BN_rand_range(ret->A, ret->mod)) goto err;
		if (BN_mod_inverse(ret->Ai, ret->A, ret->mod, ctx) == NULL)
			{
			/* this should almost never happen for good RSA keys */
			unsigned long error = ERR_peek_last_error();
			if (ERR_GET_REASON(error) == BN_R_NO_INVERSE)
				{
				if (retry_counter-- == 0)
				{
					BNerr(BN_F_BN_BLINDING_CREATE_PARAM,
						BN_R_TOO_MANY_ITERATIONS);
					goto err;
				}
				ERR_clear_error();
				}
			else
				goto err;
			}
		else
			break;
	} while (1);

	if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL)
		{
		if (!ret->bn_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx, ret->m_ctx))
			goto err;
		}
	else
		{
		if (!BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx))
			goto err;
		}

	return ret;
err:
	if (b == NULL && ret != NULL)
		{
		BN_BLINDING_free(ret);
		ret = NULL;
		}

	return ret;
}