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      1 /* crypto/dsa/dsa_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 /* Original version from Steven Schoch <schoch (at) sheba.arc.nasa.gov> */
     60 
     61 #include <stdio.h>
     62 #include "cryptlib.h"
     63 #include <openssl/bn.h>
     64 #include <openssl/dsa.h>
     65 #include <openssl/asn1.h>
     66 #ifndef OPENSSL_NO_ENGINE
     67 #include <openssl/engine.h>
     68 #endif
     69 #ifndef OPENSSL_NO_DH
     70 #include <openssl/dh.h>
     71 #endif
     72 
     73 const char DSA_version[]="DSA" OPENSSL_VERSION_PTEXT;
     74 
     75 static const DSA_METHOD *default_DSA_method = NULL;
     76 
     77 void DSA_set_default_method(const DSA_METHOD *meth)
     78 	{
     79 	default_DSA_method = meth;
     80 	}
     81 
     82 const DSA_METHOD *DSA_get_default_method(void)
     83 	{
     84 	if(!default_DSA_method)
     85 		default_DSA_method = DSA_OpenSSL();
     86 	return default_DSA_method;
     87 	}
     88 
     89 DSA *DSA_new(void)
     90 	{
     91 	return DSA_new_method(NULL);
     92 	}
     93 
     94 int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
     95 	{
     96 	/* NB: The caller is specifically setting a method, so it's not up to us
     97 	 * to deal with which ENGINE it comes from. */
     98         const DSA_METHOD *mtmp;
     99         mtmp = dsa->meth;
    100         if (mtmp->finish) mtmp->finish(dsa);
    101 #ifndef OPENSSL_NO_ENGINE
    102 	if (dsa->engine)
    103 		{
    104 		ENGINE_finish(dsa->engine);
    105 		dsa->engine = NULL;
    106 		}
    107 #endif
    108         dsa->meth = meth;
    109         if (meth->init) meth->init(dsa);
    110         return 1;
    111 	}
    112 
    113 DSA *DSA_new_method(ENGINE *engine)
    114 	{
    115 	DSA *ret;
    116 
    117 	ret=(DSA *)OPENSSL_malloc(sizeof(DSA));
    118 	if (ret == NULL)
    119 		{
    120 		DSAerr(DSA_F_DSA_NEW_METHOD,ERR_R_MALLOC_FAILURE);
    121 		return(NULL);
    122 		}
    123 	ret->meth = DSA_get_default_method();
    124 #ifndef OPENSSL_NO_ENGINE
    125 	if (engine)
    126 		{
    127 		if (!ENGINE_init(engine))
    128 			{
    129 			DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
    130 			OPENSSL_free(ret);
    131 			return NULL;
    132 			}
    133 		ret->engine = engine;
    134 		}
    135 	else
    136 		ret->engine = ENGINE_get_default_DSA();
    137 	if(ret->engine)
    138 		{
    139 		ret->meth = ENGINE_get_DSA(ret->engine);
    140 		if(!ret->meth)
    141 			{
    142 			DSAerr(DSA_F_DSA_NEW_METHOD,
    143 				ERR_R_ENGINE_LIB);
    144 			ENGINE_finish(ret->engine);
    145 			OPENSSL_free(ret);
    146 			return NULL;
    147 			}
    148 		}
    149 #endif
    150 
    151 	ret->pad=0;
    152 	ret->version=0;
    153 	ret->write_params=1;
    154 	ret->p=NULL;
    155 	ret->q=NULL;
    156 	ret->g=NULL;
    157 
    158 	ret->pub_key=NULL;
    159 	ret->priv_key=NULL;
    160 
    161 	ret->kinv=NULL;
    162 	ret->r=NULL;
    163 	ret->method_mont_p=NULL;
    164 
    165 	ret->references=1;
    166 	ret->flags=ret->meth->flags;
    167 	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
    168 	if ((ret->meth->init != NULL) && !ret->meth->init(ret))
    169 		{
    170 #ifndef OPENSSL_NO_ENGINE
    171 		if (ret->engine)
    172 			ENGINE_finish(ret->engine);
    173 #endif
    174 		CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
    175 		OPENSSL_free(ret);
    176 		ret=NULL;
    177 		}
    178 
    179 	return(ret);
    180 	}
    181 
    182 void DSA_free(DSA *r)
    183 	{
    184 	int i;
    185 
    186 	if (r == NULL) return;
    187 
    188 	i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_DSA);
    189 #ifdef REF_PRINT
    190 	REF_PRINT("DSA",r);
    191 #endif
    192 	if (i > 0) return;
    193 #ifdef REF_CHECK
    194 	if (i < 0)
    195 		{
    196 		fprintf(stderr,"DSA_free, bad reference count\n");
    197 		abort();
    198 		}
    199 #endif
    200 
    201 	if(r->meth->finish)
    202 		r->meth->finish(r);
    203 #ifndef OPENSSL_NO_ENGINE
    204 	if(r->engine)
    205 		ENGINE_finish(r->engine);
    206 #endif
    207 
    208 	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
    209 
    210 	if (r->p != NULL) BN_clear_free(r->p);
    211 	if (r->q != NULL) BN_clear_free(r->q);
    212 	if (r->g != NULL) BN_clear_free(r->g);
    213 	if (r->pub_key != NULL) BN_clear_free(r->pub_key);
    214 	if (r->priv_key != NULL) BN_clear_free(r->priv_key);
    215 	if (r->kinv != NULL) BN_clear_free(r->kinv);
    216 	if (r->r != NULL) BN_clear_free(r->r);
    217 	OPENSSL_free(r);
    218 	}
    219 
    220 int DSA_up_ref(DSA *r)
    221 	{
    222 	int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA);
    223 #ifdef REF_PRINT
    224 	REF_PRINT("DSA",r);
    225 #endif
    226 #ifdef REF_CHECK
    227 	if (i < 2)
    228 		{
    229 		fprintf(stderr, "DSA_up_ref, bad reference count\n");
    230 		abort();
    231 		}
    232 #endif
    233 	return ((i > 1) ? 1 : 0);
    234 	}
    235 
    236 int DSA_size(const DSA *r)
    237 	{
    238 	int ret,i;
    239 	ASN1_INTEGER bs;
    240 	unsigned char buf[4];	/* 4 bytes looks really small.
    241 				   However, i2d_ASN1_INTEGER() will not look
    242 				   beyond the first byte, as long as the second
    243 				   parameter is NULL. */
    244 
    245 	i=BN_num_bits(r->q);
    246 	bs.length=(i+7)/8;
    247 	bs.data=buf;
    248 	bs.type=V_ASN1_INTEGER;
    249 	/* If the top bit is set the asn1 encoding is 1 larger. */
    250 	buf[0]=0xff;
    251 
    252 	i=i2d_ASN1_INTEGER(&bs,NULL);
    253 	i+=i; /* r and s */
    254 	ret=ASN1_object_size(1,i,V_ASN1_SEQUENCE);
    255 	return(ret);
    256 	}
    257 
    258 int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
    259 	     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
    260         {
    261 	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp,
    262 				new_func, dup_func, free_func);
    263         }
    264 
    265 int DSA_set_ex_data(DSA *d, int idx, void *arg)
    266 	{
    267 	return(CRYPTO_set_ex_data(&d->ex_data,idx,arg));
    268 	}
    269 
    270 void *DSA_get_ex_data(DSA *d, int idx)
    271 	{
    272 	return(CRYPTO_get_ex_data(&d->ex_data,idx));
    273 	}
    274 
    275 #ifndef OPENSSL_NO_DH
    276 DH *DSA_dup_DH(const DSA *r)
    277 	{
    278 	/* DSA has p, q, g, optional pub_key, optional priv_key.
    279 	 * DH has p, optional length, g, optional pub_key, optional priv_key.
    280 	 */
    281 
    282 	DH *ret = NULL;
    283 
    284 	if (r == NULL)
    285 		goto err;
    286 	ret = DH_new();
    287 	if (ret == NULL)
    288 		goto err;
    289 	if (r->p != NULL)
    290 		if ((ret->p = BN_dup(r->p)) == NULL)
    291 			goto err;
    292 	if (r->q != NULL)
    293 		ret->length = BN_num_bits(r->q);
    294 	if (r->g != NULL)
    295 		if ((ret->g = BN_dup(r->g)) == NULL)
    296 			goto err;
    297 	if (r->pub_key != NULL)
    298 		if ((ret->pub_key = BN_dup(r->pub_key)) == NULL)
    299 			goto err;
    300 	if (r->priv_key != NULL)
    301 		if ((ret->priv_key = BN_dup(r->priv_key)) == NULL)
    302 			goto err;
    303 
    304 	return ret;
    305 
    306  err:
    307 	if (ret != NULL)
    308 		DH_free(ret);
    309 	return NULL;
    310 	}
    311 #endif
    312