1998-12-21 18:52:47 +08:00
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/* crypto/dh/dh_key.c */
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1998-12-21 18:56:39 +08:00
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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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1998-12-21 18:52:47 +08:00
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* All rights reserved.
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*
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* This package is an SSL implementation written
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* by Eric Young (eay@cryptsoft.com).
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* The implementation was written so as to conform with Netscapes SSL.
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*
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* This library is free for commercial and non-commercial use as long as
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* the following conditions are aheared to. The following conditions
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* apply to all code found in this distribution, be it the RC4, RSA,
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* lhash, DES, etc., code; not just the SSL code. The SSL documentation
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* included with this distribution is covered by the same copyright terms
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* except that the holder is Tim Hudson (tjh@cryptsoft.com).
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*
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* Copyright remains Eric Young's, and as such any Copyright notices in
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* the code are not to be removed.
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* If this package is used in a product, Eric Young should be given attribution
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* as the author of the parts of the library used.
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* This can be in the form of a textual message at program startup or
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* in documentation (online or textual) provided with the package.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* "This product includes cryptographic software written by
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* Eric Young (eay@cryptsoft.com)"
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* The word 'cryptographic' can be left out if the rouines from the library
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* being used are not cryptographic related :-).
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* 4. If you include any Windows specific code (or a derivative thereof) from
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* the apps directory (application code) you must include an acknowledgement:
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* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
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*
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* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* The licence and distribution terms for any publically available version or
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* derivative of this code cannot be changed. i.e. this code cannot simply be
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* copied and put under another distribution licence
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* [including the GNU Public Licence.]
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*/
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#include <stdio.h>
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#include "cryptlib.h"
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1999-04-24 06:13:45 +08:00
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#include <openssl/bn.h>
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#include <openssl/rand.h>
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#include <openssl/dh.h>
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1998-12-21 18:52:47 +08:00
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1999-08-24 07:11:32 +08:00
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static int generate_key(DH *dh);
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static int compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh);
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static int dh_bn_mod_exp(DH *dh, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
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const BIGNUM *m, BN_CTX *ctx,
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BN_MONT_CTX *m_ctx);
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static int dh_init(DH *dh);
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static int dh_finish(DH *dh);
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1999-04-20 05:31:43 +08:00
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int DH_generate_key(DH *dh)
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1999-08-24 07:11:32 +08:00
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{
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return dh->meth->generate_key(dh);
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}
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int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh)
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{
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return dh->meth->compute_key(key, pub_key, dh);
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}
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static DH_METHOD dh_ossl = {
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"OpenSSL DH Method",
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generate_key,
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compute_key,
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dh_bn_mod_exp,
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dh_init,
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dh_finish,
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0,
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NULL
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};
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DH_METHOD *DH_OpenSSL(void)
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{
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return &dh_ossl;
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}
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static int generate_key(DH *dh)
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1998-12-21 18:52:47 +08:00
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{
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int ok=0;
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unsigned int i;
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1998-12-21 19:00:56 +08:00
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BN_CTX ctx;
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BN_MONT_CTX *mont;
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1998-12-21 18:52:47 +08:00
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BIGNUM *pub_key=NULL,*priv_key=NULL;
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1998-12-21 19:00:56 +08:00
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BN_CTX_init(&ctx);
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1998-12-21 18:52:47 +08:00
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if (dh->priv_key == NULL)
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{
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i=dh->length;
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if (i == 0)
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{
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/* Make the number p-1 bits long */
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i=BN_num_bits(dh->p)-1;
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}
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priv_key=BN_new();
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if (priv_key == NULL) goto err;
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if (!BN_rand(priv_key,i,0,0)) goto err;
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}
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else
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priv_key=dh->priv_key;
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if (dh->pub_key == NULL)
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{
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pub_key=BN_new();
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if (pub_key == NULL) goto err;
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}
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else
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pub_key=dh->pub_key;
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1998-12-21 19:00:56 +08:00
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if ((dh->method_mont_p == NULL) && (dh->flags & DH_FLAG_CACHE_MONT_P))
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{
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if ((dh->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
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if (!BN_MONT_CTX_set((BN_MONT_CTX *)dh->method_mont_p,
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dh->p,&ctx)) goto err;
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}
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mont=(BN_MONT_CTX *)dh->method_mont_p;
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1999-08-24 07:11:32 +08:00
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if (!dh->meth->bn_mod_exp(dh, pub_key,dh->g,priv_key,dh->p,&ctx,mont))
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goto err;
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1998-12-21 18:52:47 +08:00
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dh->pub_key=pub_key;
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dh->priv_key=priv_key;
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ok=1;
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err:
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if (ok != 1)
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DHerr(DH_F_DH_GENERATE_KEY,ERR_R_BN_LIB);
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if ((pub_key != NULL) && (dh->pub_key == NULL)) BN_free(pub_key);
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if ((priv_key != NULL) && (dh->priv_key == NULL)) BN_free(priv_key);
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1998-12-21 19:00:56 +08:00
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BN_CTX_free(&ctx);
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1998-12-21 18:52:47 +08:00
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return(ok);
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}
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1999-08-24 07:11:32 +08:00
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static int compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh)
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1998-12-21 18:52:47 +08:00
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{
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1998-12-21 19:00:56 +08:00
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BN_CTX ctx;
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BN_MONT_CTX *mont;
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1998-12-21 18:52:47 +08:00
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BIGNUM *tmp;
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int ret= -1;
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1998-12-21 19:00:56 +08:00
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BN_CTX_init(&ctx);
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tmp= &(ctx.bn[ctx.tos++]);
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1998-12-21 18:52:47 +08:00
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if (dh->priv_key == NULL)
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{
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DHerr(DH_F_DH_COMPUTE_KEY,DH_R_NO_PRIVATE_VALUE);
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goto err;
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}
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1998-12-21 19:00:56 +08:00
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if ((dh->method_mont_p == NULL) && (dh->flags & DH_FLAG_CACHE_MONT_P))
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{
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if ((dh->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
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if (!BN_MONT_CTX_set((BN_MONT_CTX *)dh->method_mont_p,
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dh->p,&ctx)) goto err;
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}
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mont=(BN_MONT_CTX *)dh->method_mont_p;
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1999-08-24 07:11:32 +08:00
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if (!dh->meth->bn_mod_exp(dh, tmp,pub_key,dh->priv_key,dh->p,&ctx,mont))
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1998-12-21 18:52:47 +08:00
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{
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DHerr(DH_F_DH_COMPUTE_KEY,ERR_R_BN_LIB);
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goto err;
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}
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ret=BN_bn2bin(tmp,key);
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err:
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1998-12-21 19:00:56 +08:00
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BN_CTX_free(&ctx);
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1998-12-21 18:52:47 +08:00
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return(ret);
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}
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1999-08-24 07:11:32 +08:00
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static int dh_bn_mod_exp(DH *dh, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
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const BIGNUM *m, BN_CTX *ctx,
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BN_MONT_CTX *m_ctx)
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{
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return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
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}
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static int dh_init(DH *dh)
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{
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dh->flags |= DH_FLAG_CACHE_MONT_P;
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return(1);
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}
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static int dh_finish(DH *dh)
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{
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if(dh->method_mont_p)
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BN_MONT_CTX_free((BN_MONT_CTX *)dh->method_mont_p);
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return(1);
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}
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