/* crypto/bn/bn_blind.c */
/* ====================================================================
* Copyright (c) 1998-2005 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 */
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 */
unsigned 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, /* const */ 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);
ret->counter = BN_BLINDING_COUNTER;
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) == 0 && 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 == 0)
b->counter = BN_BLINDING_COUNTER;
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 (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 ((b->A == NULL) || (b->Ai == NULL))
{
BNerr(BN_F_BN_BLINDING_INVERT_EX,BN_R_NOT_INITIALIZED);
return(0);
}
if (r != NULL)
ret = BN_mod_mul(n, n, r, b->mod, ctx);
else
ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx);
if (ret >= 0)
{
if (!BN_BLINDING_update(b,ctx))
return(0);
}
bn_check_top(n);
return(ret);
}
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;
}
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, /* const */ 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;
}
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