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      1 /* crypto/dh/dh_lib.c */
      2 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      3  * All rights reserved.
      4  *
      5  * This package is an SSL implementation written
      6  * by Eric Young (eay (at) cryptsoft.com).
      7  * The implementation was written so as to conform with Netscapes SSL.
      8  *
      9  * This library is free for commercial and non-commercial use as long as
     10  * the following conditions are aheared to.  The following conditions
     11  * apply to all code found in this distribution, be it the RC4, RSA,
     12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
     13  * included with this distribution is covered by the same copyright terms
     14  * except that the holder is Tim Hudson (tjh (at) cryptsoft.com).
     15  *
     16  * Copyright remains Eric Young's, and as such any Copyright notices in
     17  * the code are not to be removed.
     18  * If this package is used in a product, Eric Young should be given attribution
     19  * as the author of the parts of the library used.
     20  * This can be in the form of a textual message at program startup or
     21  * in documentation (online or textual) provided with the package.
     22  *
     23  * Redistribution and use in source and binary forms, with or without
     24  * modification, are permitted provided that the following conditions
     25  * are met:
     26  * 1. Redistributions of source code must retain the copyright
     27  *    notice, this list of conditions and the following disclaimer.
     28  * 2. Redistributions in binary form must reproduce the above copyright
     29  *    notice, this list of conditions and the following disclaimer in the
     30  *    documentation and/or other materials provided with the distribution.
     31  * 3. All advertising materials mentioning features or use of this software
     32  *    must display the following acknowledgement:
     33  *    "This product includes cryptographic software written by
     34  *     Eric Young (eay (at) cryptsoft.com)"
     35  *    The word 'cryptographic' can be left out if the rouines from the library
     36  *    being used are not cryptographic related :-).
     37  * 4. If you include any Windows specific code (or a derivative thereof) from
     38  *    the apps directory (application code) you must include an acknowledgement:
     39  *    "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)"
     40  *
     41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
     42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     51  * SUCH DAMAGE.
     52  *
     53  * The licence and distribution terms for any publically available version or
     54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
     55  * copied and put under another distribution licence
     56  * [including the GNU Public Licence.]
     57  */
     58 
     59 #include <stdio.h>
     60 #include "cryptlib.h"
     61 #include <openssl/bn.h>
     62 #include <openssl/dh.h>
     63 #ifndef OPENSSL_NO_ENGINE
     64 #include <openssl/engine.h>
     65 #endif
     66 
     67 const char DH_version[]="Diffie-Hellman" OPENSSL_VERSION_PTEXT;
     68 
     69 static const DH_METHOD *default_DH_method = NULL;
     70 
     71 void DH_set_default_method(const DH_METHOD *meth)
     72 	{
     73 	default_DH_method = meth;
     74 	}
     75 
     76 const DH_METHOD *DH_get_default_method(void)
     77 	{
     78 	if(!default_DH_method)
     79 		default_DH_method = DH_OpenSSL();
     80 	return default_DH_method;
     81 	}
     82 
     83 int DH_set_method(DH *dh, const DH_METHOD *meth)
     84 	{
     85 	/* NB: The caller is specifically setting a method, so it's not up to us
     86 	 * to deal with which ENGINE it comes from. */
     87         const DH_METHOD *mtmp;
     88         mtmp = dh->meth;
     89         if (mtmp->finish) mtmp->finish(dh);
     90 #ifndef OPENSSL_NO_ENGINE
     91 	if (dh->engine)
     92 		{
     93 		ENGINE_finish(dh->engine);
     94 		dh->engine = NULL;
     95 		}
     96 #endif
     97         dh->meth = meth;
     98         if (meth->init) meth->init(dh);
     99         return 1;
    100 	}
    101 
    102 DH *DH_new(void)
    103 	{
    104 	return DH_new_method(NULL);
    105 	}
    106 
    107 DH *DH_new_method(ENGINE *engine)
    108 	{
    109 	DH *ret;
    110 
    111 	ret=(DH *)OPENSSL_malloc(sizeof(DH));
    112 	if (ret == NULL)
    113 		{
    114 		DHerr(DH_F_DH_NEW_METHOD,ERR_R_MALLOC_FAILURE);
    115 		return(NULL);
    116 		}
    117 
    118 	ret->meth = DH_get_default_method();
    119 #ifndef OPENSSL_NO_ENGINE
    120 	if (engine)
    121 		{
    122 		if (!ENGINE_init(engine))
    123 			{
    124 			DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
    125 			OPENSSL_free(ret);
    126 			return NULL;
    127 			}
    128 		ret->engine = engine;
    129 		}
    130 	else
    131 		ret->engine = ENGINE_get_default_DH();
    132 	if(ret->engine)
    133 		{
    134 		ret->meth = ENGINE_get_DH(ret->engine);
    135 		if(!ret->meth)
    136 			{
    137 			DHerr(DH_F_DH_NEW_METHOD,ERR_R_ENGINE_LIB);
    138 			ENGINE_finish(ret->engine);
    139 			OPENSSL_free(ret);
    140 			return NULL;
    141 			}
    142 		}
    143 #endif
    144 
    145 	ret->pad=0;
    146 	ret->version=0;
    147 	ret->p=NULL;
    148 	ret->g=NULL;
    149 	ret->length=0;
    150 	ret->pub_key=NULL;
    151 	ret->priv_key=NULL;
    152 	ret->q=NULL;
    153 	ret->j=NULL;
    154 	ret->seed = NULL;
    155 	ret->seedlen = 0;
    156 	ret->counter = NULL;
    157 	ret->method_mont_p=NULL;
    158 	ret->references = 1;
    159 	ret->flags=ret->meth->flags;
    160 	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
    161 	if ((ret->meth->init != NULL) && !ret->meth->init(ret))
    162 		{
    163 #ifndef OPENSSL_NO_ENGINE
    164 		if (ret->engine)
    165 			ENGINE_finish(ret->engine);
    166 #endif
    167 		CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
    168 		OPENSSL_free(ret);
    169 		ret=NULL;
    170 		}
    171 	return(ret);
    172 	}
    173 
    174 void DH_free(DH *r)
    175 	{
    176 	int i;
    177 	if(r == NULL) return;
    178 	i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DH);
    179 #ifdef REF_PRINT
    180 	REF_PRINT("DH",r);
    181 #endif
    182 	if (i > 0) return;
    183 #ifdef REF_CHECK
    184 	if (i < 0)
    185 		{
    186 		fprintf(stderr,"DH_free, bad reference count\n");
    187 		abort();
    188 	}
    189 #endif
    190 
    191 	if (r->meth->finish)
    192 		r->meth->finish(r);
    193 #ifndef OPENSSL_NO_ENGINE
    194 	if (r->engine)
    195 		ENGINE_finish(r->engine);
    196 #endif
    197 
    198 	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, r, &r->ex_data);
    199 
    200 	if (r->p != NULL) BN_clear_free(r->p);
    201 	if (r->g != NULL) BN_clear_free(r->g);
    202 	if (r->q != NULL) BN_clear_free(r->q);
    203 	if (r->j != NULL) BN_clear_free(r->j);
    204 	if (r->seed) OPENSSL_free(r->seed);
    205 	if (r->counter != NULL) BN_clear_free(r->counter);
    206 	if (r->pub_key != NULL) BN_clear_free(r->pub_key);
    207 	if (r->priv_key != NULL) BN_clear_free(r->priv_key);
    208 	OPENSSL_free(r);
    209 	}
    210 
    211 int DH_up_ref(DH *r)
    212 	{
    213 	int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DH);
    214 #ifdef REF_PRINT
    215 	REF_PRINT("DH",r);
    216 #endif
    217 #ifdef REF_CHECK
    218 	if (i < 2)
    219 		{
    220 		fprintf(stderr, "DH_up, bad reference count\n");
    221 		abort();
    222 		}
    223 #endif
    224 	return ((i > 1) ? 1 : 0);
    225 	}
    226 
    227 int DH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
    228 	     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
    229         {
    230 	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DH, argl, argp,
    231 				new_func, dup_func, free_func);
    232         }
    233 
    234 int DH_set_ex_data(DH *d, int idx, void *arg)
    235 	{
    236 	return(CRYPTO_set_ex_data(&d->ex_data,idx,arg));
    237 	}
    238 
    239 void *DH_get_ex_data(DH *d, int idx)
    240 	{
    241 	return(CRYPTO_get_ex_data(&d->ex_data,idx));
    242 	}
    243 
    244 int DH_size(const DH *dh)
    245 	{
    246 	return(BN_num_bytes(dh->p));
    247 	}
    248