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- /* ====================================================================
- * 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 <openssl/rsa.h>
-
- #include <string.h>
-
- #include <openssl/bn.h>
- #include <openssl/mem.h>
- #include <openssl/err.h>
-
- #include "internal.h"
- #include "../internal.h"
-
-
- #define BN_BLINDING_COUNTER 32
-
- struct bn_blinding_st {
- BIGNUM *A; /* The base blinding factor, Montgomery-encoded. */
- BIGNUM *Ai; /* The inverse of the blinding factor, Montgomery-encoded. */
- unsigned counter;
- };
-
- static int bn_blinding_create_param(BN_BLINDING *b, const BIGNUM *e,
- const BN_MONT_CTX *mont, BN_CTX *ctx);
-
- BN_BLINDING *BN_BLINDING_new(void) {
- BN_BLINDING *ret = OPENSSL_malloc(sizeof(BN_BLINDING));
- if (ret == NULL) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
- return NULL;
- }
- OPENSSL_memset(ret, 0, sizeof(BN_BLINDING));
-
- ret->A = BN_new();
- if (ret->A == NULL) {
- goto err;
- }
-
- ret->Ai = BN_new();
- if (ret->Ai == NULL) {
- goto err;
- }
-
- /* The blinding values need to be created before this blinding can be used. */
- ret->counter = BN_BLINDING_COUNTER - 1;
-
- return ret;
-
- err:
- BN_BLINDING_free(ret);
- return NULL;
- }
-
- void BN_BLINDING_free(BN_BLINDING *r) {
- if (r == NULL) {
- return;
- }
-
- BN_free(r->A);
- BN_free(r->Ai);
- OPENSSL_free(r);
- }
-
- static int bn_blinding_update(BN_BLINDING *b, const BIGNUM *e,
- const BN_MONT_CTX *mont, BN_CTX *ctx) {
- if (++b->counter == BN_BLINDING_COUNTER) {
- /* re-create blinding parameters */
- if (!bn_blinding_create_param(b, e, mont, ctx)) {
- goto err;
- }
- b->counter = 0;
- } else {
- if (!BN_mod_mul_montgomery(b->A, b->A, b->A, mont, ctx) ||
- !BN_mod_mul_montgomery(b->Ai, b->Ai, b->Ai, mont, ctx)) {
- goto err;
- }
- }
-
- return 1;
-
- err:
- /* |A| and |Ai| may be in an inconsistent state so they both need to be
- * replaced the next time this blinding is used. Note that this is only
- * sufficient because support for |BN_BLINDING_NO_UPDATE| and
- * |BN_BLINDING_NO_RECREATE| was previously dropped. */
- b->counter = BN_BLINDING_COUNTER - 1;
-
- return 0;
- }
-
- int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, const BIGNUM *e,
- const BN_MONT_CTX *mont, BN_CTX *ctx) {
- /* |n| is not Montgomery-encoded and |b->A| is. |BN_mod_mul_montgomery|
- * cancels one Montgomery factor, so the resulting value of |n| is unencoded.
- */
- if (!bn_blinding_update(b, e, mont, ctx) ||
- !BN_mod_mul_montgomery(n, n, b->A, mont, ctx)) {
- return 0;
- }
-
- return 1;
- }
-
- int BN_BLINDING_invert(BIGNUM *n, const BN_BLINDING *b, BN_MONT_CTX *mont,
- BN_CTX *ctx) {
- /* |n| is not Montgomery-encoded and |b->A| is. |BN_mod_mul_montgomery|
- * cancels one Montgomery factor, so the resulting value of |n| is unencoded.
- */
- return BN_mod_mul_montgomery(n, n, b->Ai, mont, ctx);
- }
-
- static int bn_blinding_create_param(BN_BLINDING *b, const BIGNUM *e,
- const BN_MONT_CTX *mont, BN_CTX *ctx) {
- int retry_counter = 32;
-
- do {
- if (!BN_rand_range_ex(b->A, 1, &mont->N)) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- /* |BN_from_montgomery| + |BN_mod_inverse_blinded| is equivalent to, but
- * more efficient than, |BN_mod_inverse_blinded| + |BN_to_montgomery|. */
- if (!BN_from_montgomery(b->Ai, b->A, mont, ctx)) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- int no_inverse;
- if (BN_mod_inverse_blinded(b->Ai, &no_inverse, b->Ai, mont, ctx)) {
- break;
- }
-
- if (!no_inverse) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- /* For reasonably-sized RSA keys, it should almost never be the case that a
- * random value doesn't have an inverse. */
- if (retry_counter-- == 0) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_TOO_MANY_ITERATIONS);
- return 0;
- }
- ERR_clear_error();
- } while (1);
-
- if (!BN_mod_exp_mont(b->A, b->A, e, &mont->N, ctx, mont)) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- if (!BN_to_montgomery(b->A, b->A, mont, ctx)) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- return 1;
- }
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