xref: /openbsd-src/lib/libcrypto/dsa/dsa_lib.c (revision 15d1ec5d30ceebc4c1addb2e30309472c3d7f876)
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 #ifndef OPENSSL_NO_ENGINE
67 #include <openssl/engine.h>
68 #endif
69 
70 const char *DSA_version="DSA" OPENSSL_VERSION_PTEXT;
71 
72 static const DSA_METHOD *default_DSA_method = NULL;
73 
74 void DSA_set_default_method(const DSA_METHOD *meth)
75 	{
76 	default_DSA_method = meth;
77 	}
78 
79 const DSA_METHOD *DSA_get_default_method(void)
80 	{
81 	if(!default_DSA_method)
82 		default_DSA_method = DSA_OpenSSL();
83 	return default_DSA_method;
84 	}
85 
86 DSA *DSA_new(void)
87 	{
88 	return DSA_new_method(NULL);
89 	}
90 
91 int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
92 	{
93 	/* NB: The caller is specifically setting a method, so it's not up to us
94 	 * to deal with which ENGINE it comes from. */
95         const DSA_METHOD *mtmp;
96         mtmp = dsa->meth;
97         if (mtmp->finish) mtmp->finish(dsa);
98 #ifndef OPENSSL_NO_ENGINE
99 	if (dsa->engine)
100 		{
101 		ENGINE_finish(dsa->engine);
102 		dsa->engine = NULL;
103 		}
104 #endif
105         dsa->meth = meth;
106         if (meth->init) meth->init(dsa);
107         return 1;
108 	}
109 
110 DSA *DSA_new_method(ENGINE *engine)
111 	{
112 	DSA *ret;
113 
114 	ret=(DSA *)OPENSSL_malloc(sizeof(DSA));
115 	if (ret == NULL)
116 		{
117 		DSAerr(DSA_F_DSA_NEW_METHOD,ERR_R_MALLOC_FAILURE);
118 		return(NULL);
119 		}
120 	ret->meth = DSA_get_default_method();
121 #ifndef OPENSSL_NO_ENGINE
122 	if (engine)
123 		{
124 		if (!ENGINE_init(engine))
125 			{
126 			DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
127 			OPENSSL_free(ret);
128 			return NULL;
129 			}
130 		ret->engine = engine;
131 		}
132 	else
133 		ret->engine = ENGINE_get_default_DSA();
134 	if(ret->engine)
135 		{
136 		ret->meth = ENGINE_get_DSA(ret->engine);
137 		if(!ret->meth)
138 			{
139 			DSAerr(DSA_F_DSA_NEW_METHOD,
140 				ERR_R_ENGINE_LIB);
141 			ENGINE_finish(ret->engine);
142 			OPENSSL_free(ret);
143 			return NULL;
144 			}
145 		}
146 #endif
147 
148 	ret->pad=0;
149 	ret->version=0;
150 	ret->write_params=1;
151 	ret->p=NULL;
152 	ret->q=NULL;
153 	ret->g=NULL;
154 
155 	ret->pub_key=NULL;
156 	ret->priv_key=NULL;
157 
158 	ret->kinv=NULL;
159 	ret->r=NULL;
160 	ret->method_mont_p=NULL;
161 
162 	ret->references=1;
163 	ret->flags=ret->meth->flags;
164 	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
165 	if ((ret->meth->init != NULL) && !ret->meth->init(ret))
166 		{
167 #ifndef OPENSSL_NO_ENGINE
168 		if (ret->engine)
169 			ENGINE_finish(ret->engine);
170 #endif
171 		CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
172 		OPENSSL_free(ret);
173 		ret=NULL;
174 		}
175 
176 	return(ret);
177 	}
178 
179 void DSA_free(DSA *r)
180 	{
181 	int i;
182 
183 	if (r == NULL) return;
184 
185 	i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_DSA);
186 #ifdef REF_PRINT
187 	REF_PRINT("DSA",r);
188 #endif
189 	if (i > 0) return;
190 #ifdef REF_CHECK
191 	if (i < 0)
192 		{
193 		fprintf(stderr,"DSA_free, bad reference count\n");
194 		abort();
195 		}
196 #endif
197 
198 	if(r->meth->finish)
199 		r->meth->finish(r);
200 #ifndef OPENSSL_NO_ENGINE
201 	if(r->engine)
202 		ENGINE_finish(r->engine);
203 #endif
204 
205 	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
206 
207 	if (r->p != NULL) BN_clear_free(r->p);
208 	if (r->q != NULL) BN_clear_free(r->q);
209 	if (r->g != NULL) BN_clear_free(r->g);
210 	if (r->pub_key != NULL) BN_clear_free(r->pub_key);
211 	if (r->priv_key != NULL) BN_clear_free(r->priv_key);
212 	if (r->kinv != NULL) BN_clear_free(r->kinv);
213 	if (r->r != NULL) BN_clear_free(r->r);
214 	OPENSSL_free(r);
215 	}
216 
217 int DSA_up_ref(DSA *r)
218 	{
219 	int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA);
220 #ifdef REF_PRINT
221 	REF_PRINT("DSA",r);
222 #endif
223 #ifdef REF_CHECK
224 	if (i < 2)
225 		{
226 		fprintf(stderr, "DSA_up_ref, bad reference count\n");
227 		abort();
228 		}
229 #endif
230 	return ((i > 1) ? 1 : 0);
231 	}
232 
233 int DSA_size(const DSA *r)
234 	{
235 	int ret,i;
236 	ASN1_INTEGER bs;
237 	unsigned char buf[4];	/* 4 bytes looks really small.
238 				   However, i2d_ASN1_INTEGER() will not look
239 				   beyond the first byte, as long as the second
240 				   parameter is NULL. */
241 
242 	i=BN_num_bits(r->q);
243 	bs.length=(i+7)/8;
244 	bs.data=buf;
245 	bs.type=V_ASN1_INTEGER;
246 	/* If the top bit is set the asn1 encoding is 1 larger. */
247 	buf[0]=0xff;
248 
249 	i=i2d_ASN1_INTEGER(&bs,NULL);
250 	i+=i; /* r and s */
251 	ret=ASN1_object_size(1,i,V_ASN1_SEQUENCE);
252 	return(ret);
253 	}
254 
255 int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
256 	     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
257         {
258 	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp,
259 				new_func, dup_func, free_func);
260         }
261 
262 int DSA_set_ex_data(DSA *d, int idx, void *arg)
263 	{
264 	return(CRYPTO_set_ex_data(&d->ex_data,idx,arg));
265 	}
266 
267 void *DSA_get_ex_data(DSA *d, int idx)
268 	{
269 	return(CRYPTO_get_ex_data(&d->ex_data,idx));
270 	}
271 
272 #ifndef OPENSSL_NO_DH
273 DH *DSA_dup_DH(const DSA *r)
274 	{
275 	/* DSA has p, q, g, optional pub_key, optional priv_key.
276 	 * DH has p, optional length, g, optional pub_key, optional priv_key.
277 	 */
278 
279 	DH *ret = NULL;
280 
281 	if (r == NULL)
282 		goto err;
283 	ret = DH_new();
284 	if (ret == NULL)
285 		goto err;
286 	if (r->p != NULL)
287 		if ((ret->p = BN_dup(r->p)) == NULL)
288 			goto err;
289 	if (r->q != NULL)
290 		ret->length = BN_num_bits(r->q);
291 	if (r->g != NULL)
292 		if ((ret->g = BN_dup(r->g)) == NULL)
293 			goto err;
294 	if (r->pub_key != NULL)
295 		if ((ret->pub_key = BN_dup(r->pub_key)) == NULL)
296 			goto err;
297 	if (r->priv_key != NULL)
298 		if ((ret->priv_key = BN_dup(r->priv_key)) == NULL)
299 			goto err;
300 
301 	return ret;
302 
303  err:
304 	if (ret != NULL)
305 		DH_free(ret);
306 	return NULL;
307 	}
308 #endif
309