xref: /openbsd-src/lib/libcrypto/dsa/dsa_lib.c (revision ce7e0fc6a9d74d25b78fb6ad846387717f5172b6)
1 /* crypto/dsa/dsa_lib.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@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@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@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@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@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 #include <openssl/engine.h>
67 
68 const char *DSA_version="DSA" OPENSSL_VERSION_PTEXT;
69 
70 static const DSA_METHOD *default_DSA_method = NULL;
71 
72 void DSA_set_default_method(const DSA_METHOD *meth)
73 	{
74 	default_DSA_method = meth;
75 	}
76 
77 const DSA_METHOD *DSA_get_default_method(void)
78 	{
79 	if(!default_DSA_method)
80 		default_DSA_method = DSA_OpenSSL();
81 	return default_DSA_method;
82 	}
83 
84 DSA *DSA_new(void)
85 	{
86 	return DSA_new_method(NULL);
87 	}
88 
89 int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
90 	{
91 	/* NB: The caller is specifically setting a method, so it's not up to us
92 	 * to deal with which ENGINE it comes from. */
93         const DSA_METHOD *mtmp;
94         mtmp = dsa->meth;
95         if (mtmp->finish) mtmp->finish(dsa);
96 	if (dsa->engine)
97 		{
98 		ENGINE_finish(dsa->engine);
99 		dsa->engine = NULL;
100 		}
101         dsa->meth = meth;
102         if (meth->init) meth->init(dsa);
103         return 1;
104 	}
105 
106 DSA *DSA_new_method(ENGINE *engine)
107 	{
108 	DSA *ret;
109 
110 	ret=(DSA *)OPENSSL_malloc(sizeof(DSA));
111 	if (ret == NULL)
112 		{
113 		DSAerr(DSA_F_DSA_NEW_METHOD,ERR_R_MALLOC_FAILURE);
114 		return(NULL);
115 		}
116 	ret->meth = DSA_get_default_method();
117 	if (engine)
118 		{
119 		if (!ENGINE_init(engine))
120 			{
121 			DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
122 			OPENSSL_free(ret);
123 			return NULL;
124 			}
125 		ret->engine = engine;
126 		}
127 	else
128 		ret->engine = ENGINE_get_default_DSA();
129 	if(ret->engine)
130 		{
131 		ret->meth = ENGINE_get_DSA(ret->engine);
132 		if(!ret->meth)
133 			{
134 			DSAerr(DSA_F_DSA_NEW_METHOD,
135 				ERR_R_ENGINE_LIB);
136 			ENGINE_finish(ret->engine);
137 			OPENSSL_free(ret);
138 			return NULL;
139 			}
140 		}
141 
142 	ret->pad=0;
143 	ret->version=0;
144 	ret->write_params=1;
145 	ret->p=NULL;
146 	ret->q=NULL;
147 	ret->g=NULL;
148 
149 	ret->pub_key=NULL;
150 	ret->priv_key=NULL;
151 
152 	ret->kinv=NULL;
153 	ret->r=NULL;
154 	ret->method_mont_p=NULL;
155 
156 	ret->references=1;
157 	ret->flags=ret->meth->flags;
158 	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
159 	if ((ret->meth->init != NULL) && !ret->meth->init(ret))
160 		{
161 		if (ret->engine)
162 			ENGINE_finish(ret->engine);
163 		CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
164 		OPENSSL_free(ret);
165 		ret=NULL;
166 		}
167 
168 	return(ret);
169 	}
170 
171 void DSA_free(DSA *r)
172 	{
173 	int i;
174 
175 	if (r == NULL) return;
176 
177 	i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_DSA);
178 #ifdef REF_PRINT
179 	REF_PRINT("DSA",r);
180 #endif
181 	if (i > 0) return;
182 #ifdef REF_CHECK
183 	if (i < 0)
184 		{
185 		fprintf(stderr,"DSA_free, bad reference count\n");
186 		abort();
187 		}
188 #endif
189 
190 	if(r->meth->finish)
191 		r->meth->finish(r);
192 	if(r->engine)
193 		ENGINE_finish(r->engine);
194 
195 	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
196 
197 	if (r->p != NULL) BN_clear_free(r->p);
198 	if (r->q != NULL) BN_clear_free(r->q);
199 	if (r->g != NULL) BN_clear_free(r->g);
200 	if (r->pub_key != NULL) BN_clear_free(r->pub_key);
201 	if (r->priv_key != NULL) BN_clear_free(r->priv_key);
202 	if (r->kinv != NULL) BN_clear_free(r->kinv);
203 	if (r->r != NULL) BN_clear_free(r->r);
204 	OPENSSL_free(r);
205 	}
206 
207 int DSA_up_ref(DSA *r)
208 	{
209 	int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA);
210 #ifdef REF_PRINT
211 	REF_PRINT("DSA",r);
212 #endif
213 #ifdef REF_CHECK
214 	if (i < 2)
215 		{
216 		fprintf(stderr, "DSA_up_ref, bad reference count\n");
217 		abort();
218 		}
219 #endif
220 	return ((i > 1) ? 1 : 0);
221 	}
222 
223 int DSA_size(const DSA *r)
224 	{
225 	int ret,i;
226 	ASN1_INTEGER bs;
227 	unsigned char buf[4];
228 
229 	i=BN_num_bits(r->q);
230 	bs.length=(i+7)/8;
231 	bs.data=buf;
232 	bs.type=V_ASN1_INTEGER;
233 	/* If the top bit is set the asn1 encoding is 1 larger. */
234 	buf[0]=0xff;
235 
236 	i=i2d_ASN1_INTEGER(&bs,NULL);
237 	i+=i; /* r and s */
238 	ret=ASN1_object_size(1,i,V_ASN1_SEQUENCE);
239 	return(ret);
240 	}
241 
242 int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
243 	     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
244         {
245 	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp,
246 				new_func, dup_func, free_func);
247         }
248 
249 int DSA_set_ex_data(DSA *d, int idx, void *arg)
250 	{
251 	return(CRYPTO_set_ex_data(&d->ex_data,idx,arg));
252 	}
253 
254 void *DSA_get_ex_data(DSA *d, int idx)
255 	{
256 	return(CRYPTO_get_ex_data(&d->ex_data,idx));
257 	}
258 
259 #ifndef OPENSSL_NO_DH
260 DH *DSA_dup_DH(const DSA *r)
261 	{
262 	/* DSA has p, q, g, optional pub_key, optional priv_key.
263 	 * DH has p, optional length, g, optional pub_key, optional priv_key.
264 	 */
265 
266 	DH *ret = NULL;
267 
268 	if (r == NULL)
269 		goto err;
270 	ret = DH_new();
271 	if (ret == NULL)
272 		goto err;
273 	if (r->p != NULL)
274 		if ((ret->p = BN_dup(r->p)) == NULL)
275 			goto err;
276 	if (r->q != NULL)
277 		ret->length = BN_num_bits(r->q);
278 	if (r->g != NULL)
279 		if ((ret->g = BN_dup(r->g)) == NULL)
280 			goto err;
281 	if (r->pub_key != NULL)
282 		if ((ret->pub_key = BN_dup(r->pub_key)) == NULL)
283 			goto err;
284 	if (r->priv_key != NULL)
285 		if ((ret->priv_key = BN_dup(r->priv_key)) == NULL)
286 			goto err;
287 
288 	return ret;
289 
290  err:
291 	if (ret != NULL)
292 		DH_free(ret);
293 	return NULL;
294 	}
295 #endif
296