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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 #ifdef OPENSSL_FIPS
     74 #include <openssl/fips.h>
     75 #endif
     76 
     77 const char DSA_version[]="DSA" OPENSSL_VERSION_PTEXT;
     78 
     79 static const DSA_METHOD *default_DSA_method = NULL;
     80 
     81 void DSA_set_default_method(const DSA_METHOD *meth)
     82 	{
     83 	default_DSA_method = meth;
     84 	}
     85 
     86 const DSA_METHOD *DSA_get_default_method(void)
     87 	{
     88 	if(!default_DSA_method)
     89 		{
     90 #ifdef OPENSSL_FIPS
     91 		if (FIPS_mode())
     92 			return FIPS_dsa_openssl();
     93 		else
     94 			return DSA_OpenSSL();
     95 #else
     96 		default_DSA_method = DSA_OpenSSL();
     97 #endif
     98 		}
     99 	return default_DSA_method;
    100 	}
    101 
    102 DSA *DSA_new(void)
    103 	{
    104 	return DSA_new_method(NULL);
    105 	}
    106 
    107 int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
    108 	{
    109 	/* NB: The caller is specifically setting a method, so it's not up to us
    110 	 * to deal with which ENGINE it comes from. */
    111         const DSA_METHOD *mtmp;
    112         mtmp = dsa->meth;
    113         if (mtmp->finish) mtmp->finish(dsa);
    114 #ifndef OPENSSL_NO_ENGINE
    115 	if (dsa->engine)
    116 		{
    117 		ENGINE_finish(dsa->engine);
    118 		dsa->engine = NULL;
    119 		}
    120 #endif
    121         dsa->meth = meth;
    122         if (meth->init) meth->init(dsa);
    123         return 1;
    124 	}
    125 
    126 DSA *DSA_new_method(ENGINE *engine)
    127 	{
    128 	DSA *ret;
    129 
    130 	ret=(DSA *)OPENSSL_malloc(sizeof(DSA));
    131 	if (ret == NULL)
    132 		{
    133 		DSAerr(DSA_F_DSA_NEW_METHOD,ERR_R_MALLOC_FAILURE);
    134 		return(NULL);
    135 		}
    136 	ret->meth = DSA_get_default_method();
    137 #ifndef OPENSSL_NO_ENGINE
    138 	if (engine)
    139 		{
    140 		if (!ENGINE_init(engine))
    141 			{
    142 			DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
    143 			OPENSSL_free(ret);
    144 			return NULL;
    145 			}
    146 		ret->engine = engine;
    147 		}
    148 	else
    149 		ret->engine = ENGINE_get_default_DSA();
    150 	if(ret->engine)
    151 		{
    152 		ret->meth = ENGINE_get_DSA(ret->engine);
    153 		if(!ret->meth)
    154 			{
    155 			DSAerr(DSA_F_DSA_NEW_METHOD,
    156 				ERR_R_ENGINE_LIB);
    157 			ENGINE_finish(ret->engine);
    158 			OPENSSL_free(ret);
    159 			return NULL;
    160 			}
    161 		}
    162 #endif
    163 
    164 	ret->pad=0;
    165 	ret->version=0;
    166 	ret->write_params=1;
    167 	ret->p=NULL;
    168 	ret->q=NULL;
    169 	ret->g=NULL;
    170 
    171 	ret->pub_key=NULL;
    172 	ret->priv_key=NULL;
    173 
    174 	ret->kinv=NULL;
    175 	ret->r=NULL;
    176 	ret->method_mont_p=NULL;
    177 
    178 	ret->references=1;
    179 	ret->flags=ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW;
    180 	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
    181 	if ((ret->meth->init != NULL) && !ret->meth->init(ret))
    182 		{
    183 #ifndef OPENSSL_NO_ENGINE
    184 		if (ret->engine)
    185 			ENGINE_finish(ret->engine);
    186 #endif
    187 		CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
    188 		OPENSSL_free(ret);
    189 		ret=NULL;
    190 		}
    191 
    192 	return(ret);
    193 	}
    194 
    195 void DSA_free(DSA *r)
    196 	{
    197 	int i;
    198 
    199 	if (r == NULL) return;
    200 
    201 	i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_DSA);
    202 #ifdef REF_PRINT
    203 	REF_PRINT("DSA",r);
    204 #endif
    205 	if (i > 0) return;
    206 #ifdef REF_CHECK
    207 	if (i < 0)
    208 		{
    209 		fprintf(stderr,"DSA_free, bad reference count\n");
    210 		abort();
    211 		}
    212 #endif
    213 
    214 	if(r->meth->finish)
    215 		r->meth->finish(r);
    216 #ifndef OPENSSL_NO_ENGINE
    217 	if(r->engine)
    218 		ENGINE_finish(r->engine);
    219 #endif
    220 
    221 	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
    222 
    223 	if (r->p != NULL) BN_clear_free(r->p);
    224 	if (r->q != NULL) BN_clear_free(r->q);
    225 	if (r->g != NULL) BN_clear_free(r->g);
    226 	if (r->pub_key != NULL) BN_clear_free(r->pub_key);
    227 	if (r->priv_key != NULL) BN_clear_free(r->priv_key);
    228 	if (r->kinv != NULL) BN_clear_free(r->kinv);
    229 	if (r->r != NULL) BN_clear_free(r->r);
    230 	OPENSSL_free(r);
    231 	}
    232 
    233 int DSA_up_ref(DSA *r)
    234 	{
    235 	int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA);
    236 #ifdef REF_PRINT
    237 	REF_PRINT("DSA",r);
    238 #endif
    239 #ifdef REF_CHECK
    240 	if (i < 2)
    241 		{
    242 		fprintf(stderr, "DSA_up_ref, bad reference count\n");
    243 		abort();
    244 		}
    245 #endif
    246 	return ((i > 1) ? 1 : 0);
    247 	}
    248 
    249 int DSA_size(const DSA *r)
    250 	{
    251 	int ret,i;
    252 	ASN1_INTEGER bs;
    253 	unsigned char buf[4];	/* 4 bytes looks really small.
    254 				   However, i2d_ASN1_INTEGER() will not look
    255 				   beyond the first byte, as long as the second
    256 				   parameter is NULL. */
    257 
    258 	i=BN_num_bits(r->q);
    259 	bs.length=(i+7)/8;
    260 	bs.data=buf;
    261 	bs.type=V_ASN1_INTEGER;
    262 	/* If the top bit is set the asn1 encoding is 1 larger. */
    263 	buf[0]=0xff;
    264 
    265 	i=i2d_ASN1_INTEGER(&bs,NULL);
    266 	i+=i; /* r and s */
    267 	ret=ASN1_object_size(1,i,V_ASN1_SEQUENCE);
    268 	return(ret);
    269 	}
    270 
    271 int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
    272 	     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
    273         {
    274 	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp,
    275 				new_func, dup_func, free_func);
    276         }
    277 
    278 int DSA_set_ex_data(DSA *d, int idx, void *arg)
    279 	{
    280 	return(CRYPTO_set_ex_data(&d->ex_data,idx,arg));
    281 	}
    282 
    283 void *DSA_get_ex_data(DSA *d, int idx)
    284 	{
    285 	return(CRYPTO_get_ex_data(&d->ex_data,idx));
    286 	}
    287 
    288 #ifndef OPENSSL_NO_DH
    289 DH *DSA_dup_DH(const DSA *r)
    290 	{
    291 	/* DSA has p, q, g, optional pub_key, optional priv_key.
    292 	 * DH has p, optional length, g, optional pub_key, optional priv_key,
    293 	 * optional q.
    294 	 */
    295 
    296 	DH *ret = NULL;
    297 
    298 	if (r == NULL)
    299 		goto err;
    300 	ret = DH_new();
    301 	if (ret == NULL)
    302 		goto err;
    303 	if (r->p != NULL)
    304 		if ((ret->p = BN_dup(r->p)) == NULL)
    305 			goto err;
    306 	if (r->q != NULL)
    307 		{
    308 		ret->length = BN_num_bits(r->q);
    309 		if ((ret->q = BN_dup(r->q)) == NULL)
    310 			goto err;
    311 		}
    312 	if (r->g != NULL)
    313 		if ((ret->g = BN_dup(r->g)) == NULL)
    314 			goto err;
    315 	if (r->pub_key != NULL)
    316 		if ((ret->pub_key = BN_dup(r->pub_key)) == NULL)
    317 			goto err;
    318 	if (r->priv_key != NULL)
    319 		if ((ret->priv_key = BN_dup(r->priv_key)) == NULL)
    320 			goto err;
    321 
    322 	return ret;
    323 
    324  err:
    325 	if (ret != NULL)
    326 		DH_free(ret);
    327 	return NULL;
    328 	}
    329 #endif
    330