crypto/bn/bn_blind.c - platform/external/openssl.git - Git at Google

 /* 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;
 }
	/* 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;
	}