dsa_lib.c revision 296465 
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#ifdef OPENSSL_FIPS
80    if (FIPS_mode() && !(meth->flags & DSA_FLAG_FIPS_METHOD)) {
81        DSAerr(DSA_F_DSA_SET_DEFAULT_METHOD, DSA_R_NON_FIPS_METHOD);
82        return;
83    }
84#endif
85
86    default_DSA_method = meth;
87}
88
89const DSA_METHOD *DSA_get_default_method(void)
90{
91    if (!default_DSA_method)
92        default_DSA_method = DSA_OpenSSL();
93    return default_DSA_method;
94}
95
96DSA *DSA_new(void)
97{
98    return DSA_new_method(NULL);
99}
100
101int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
102{
103    /*
104     * NB: The caller is specifically setting a method, so it's not up to us
105     * to deal with which ENGINE it comes from.
106     */
107    const DSA_METHOD *mtmp;
108#ifdef OPENSSL_FIPS
109    if (FIPS_mode() && !(meth->flags & DSA_FLAG_FIPS_METHOD)) {
110        DSAerr(DSA_F_DSA_SET_METHOD, DSA_R_NON_FIPS_METHOD);
111        return 0;
112    }
113#endif
114    mtmp = dsa->meth;
115    if (mtmp->finish)
116        mtmp->finish(dsa);
117#ifndef OPENSSL_NO_ENGINE
118    if (dsa->engine) {
119        ENGINE_finish(dsa->engine);
120        dsa->engine = NULL;
121    }
122#endif
123    dsa->meth = meth;
124    if (meth->init)
125        meth->init(dsa);
126    return 1;
127}
128
129DSA *DSA_new_method(ENGINE *engine)
130{
131    DSA *ret;
132
133    ret = (DSA *)OPENSSL_malloc(sizeof(DSA));
134    if (ret == NULL) {
135        DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
136        return (NULL);
137    }
138    ret->meth = DSA_get_default_method();
139#ifndef OPENSSL_NO_ENGINE
140    if (engine) {
141        if (!ENGINE_init(engine)) {
142            DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
143            OPENSSL_free(ret);
144            return NULL;
145        }
146        ret->engine = engine;
147    } else
148        ret->engine = ENGINE_get_default_DSA();
149    if (ret->engine) {
150        ret->meth = ENGINE_get_DSA(ret->engine);
151        if (!ret->meth) {
152            DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
153            ENGINE_finish(ret->engine);
154            OPENSSL_free(ret);
155            return NULL;
156        }
157    }
158#endif
159#ifdef OPENSSL_FIPS
160    if (FIPS_mode() && !(ret->meth->flags & DSA_FLAG_FIPS_METHOD)) {
161        DSAerr(DSA_F_DSA_NEW_METHOD, DSA_R_NON_FIPS_METHOD);
162# ifndef OPENSSL_NO_ENGINE
163        if (ret->engine)
164            ENGINE_finish(ret->engine);
165# endif
166        OPENSSL_free(ret);
167        return NULL;
168    }
169#endif
170
171    ret->pad = 0;
172    ret->version = 0;
173    ret->write_params = 1;
174    ret->p = NULL;
175    ret->q = NULL;
176    ret->g = NULL;
177
178    ret->pub_key = NULL;
179    ret->priv_key = NULL;
180
181    ret->kinv = NULL;
182    ret->r = NULL;
183    ret->method_mont_p = NULL;
184
185    ret->references = 1;
186    ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW;
187    CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
188    if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
189#ifndef OPENSSL_NO_ENGINE
190        if (ret->engine)
191            ENGINE_finish(ret->engine);
192#endif
193        CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
194        OPENSSL_free(ret);
195        ret = NULL;
196    }
197
198    return (ret);
199}
200
201void DSA_free(DSA *r)
202{
203    int i;
204
205    if (r == NULL)
206        return;
207
208    i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DSA);
209#ifdef REF_PRINT
210    REF_PRINT("DSA", r);
211#endif
212    if (i > 0)
213        return;
214#ifdef REF_CHECK
215    if (i < 0) {
216        fprintf(stderr, "DSA_free, bad reference count\n");
217        abort();
218    }
219#endif
220
221    if (r->meth->finish)
222        r->meth->finish(r);
223#ifndef OPENSSL_NO_ENGINE
224    if (r->engine)
225        ENGINE_finish(r->engine);
226#endif
227
228    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
229
230    if (r->p != NULL)
231        BN_clear_free(r->p);
232    if (r->q != NULL)
233        BN_clear_free(r->q);
234    if (r->g != NULL)
235        BN_clear_free(r->g);
236    if (r->pub_key != NULL)
237        BN_clear_free(r->pub_key);
238    if (r->priv_key != NULL)
239        BN_clear_free(r->priv_key);
240    if (r->kinv != NULL)
241        BN_clear_free(r->kinv);
242    if (r->r != NULL)
243        BN_clear_free(r->r);
244    OPENSSL_free(r);
245}
246
247int DSA_up_ref(DSA *r)
248{
249    int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA);
250#ifdef REF_PRINT
251    REF_PRINT("DSA", r);
252#endif
253#ifdef REF_CHECK
254    if (i < 2) {
255        fprintf(stderr, "DSA_up_ref, bad reference count\n");
256        abort();
257    }
258#endif
259    return ((i > 1) ? 1 : 0);
260}
261
262int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
263                         CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
264{
265    return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp,
266                                   new_func, dup_func, free_func);
267}
268
269int DSA_set_ex_data(DSA *d, int idx, void *arg)
270{
271    return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
272}
273
274void *DSA_get_ex_data(DSA *d, int idx)
275{
276    return (CRYPTO_get_ex_data(&d->ex_data, idx));
277}
278
279#ifndef OPENSSL_NO_DH
280DH *DSA_dup_DH(const DSA *r)
281{
282    /*
283     * DSA has p, q, g, optional pub_key, optional priv_key. DH has p,
284     * optional length, g, optional pub_key, optional priv_key.
285     */
286
287    DH *ret = NULL;
288
289    if (r == NULL)
290        goto err;
291    ret = DH_new();
292    if (ret == NULL)
293        goto err;
294    if (r->p != NULL)
295        if ((ret->p = BN_dup(r->p)) == NULL)
296            goto err;
297    if (r->q != NULL)
298        ret->length = BN_num_bits(r->q);
299    if (r->g != NULL)
300        if ((ret->g = BN_dup(r->g)) == NULL)
301            goto err;
302    if (r->pub_key != NULL)
303        if ((ret->pub_key = BN_dup(r->pub_key)) == NULL)
304            goto err;
305    if (r->priv_key != NULL)
306        if ((ret->priv_key = BN_dup(r->priv_key)) == NULL)
307            goto err;
308
309    return ret;
310
311 err:
312    if (ret != NULL)
313        DH_free(ret);
314    return NULL;
315}
316#endif
317