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#ifndef OPENSSL_NO_DH
70#include <openssl/dh.h>
71#endif
72
73const char DSA_version[]="DSA" OPENSSL_VERSION_PTEXT;
74
75static const DSA_METHOD *default_DSA_method = NULL;
76
77void DSA_set_default_method(const DSA_METHOD *meth)
78	{
79	default_DSA_method = meth;
80	}
81
82const 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
89DSA *DSA_new(void)
90	{
91	return DSA_new_method(NULL);
92	}
93
94int 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
113DSA *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
182void 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
220int 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
236int 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
258int 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
265int DSA_set_ex_data(DSA *d, int idx, void *arg)
266	{
267	return(CRYPTO_set_ex_data(&d->ex_data,idx,arg));
268	}
269
270void *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
276DH *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