dsa_lib.c revision 296341 
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
73#ifdef OPENSSL_FIPS
74# include <openssl/fips.h>
75#endif
76
77const char DSA_version[] = "DSA" OPENSSL_VERSION_PTEXT;
78
79static const DSA_METHOD *default_DSA_method = NULL;
80
81void DSA_set_default_method(const DSA_METHOD *meth)
82{
83    default_DSA_method = meth;
84}
85
86const DSA_METHOD *DSA_get_default_method(void)
87{
88    if (!default_DSA_method) {
89#ifdef OPENSSL_FIPS
90        if (FIPS_mode())
91            return FIPS_dsa_openssl();
92        else
93            return DSA_OpenSSL();
94#else
95        default_DSA_method = DSA_OpenSSL();
96#endif
97    }
98    return default_DSA_method;
99}
100
101DSA *DSA_new(void)
102{
103    return DSA_new_method(NULL);
104}
105
106int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
107{
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     */
112    const DSA_METHOD *mtmp;
113    mtmp = dsa->meth;
114    if (mtmp->finish)
115        mtmp->finish(dsa);
116#ifndef OPENSSL_NO_ENGINE
117    if (dsa->engine) {
118        ENGINE_finish(dsa->engine);
119        dsa->engine = NULL;
120    }
121#endif
122    dsa->meth = meth;
123    if (meth->init)
124        meth->init(dsa);
125    return 1;
126}
127
128DSA *DSA_new_method(ENGINE *engine)
129{
130    DSA *ret;
131
132    ret = (DSA *)OPENSSL_malloc(sizeof(DSA));
133    if (ret == NULL) {
134        DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
135        return (NULL);
136    }
137    ret->meth = DSA_get_default_method();
138#ifndef OPENSSL_NO_ENGINE
139    if (engine) {
140        if (!ENGINE_init(engine)) {
141            DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
142            OPENSSL_free(ret);
143            return NULL;
144        }
145        ret->engine = engine;
146    } else
147        ret->engine = ENGINE_get_default_DSA();
148    if (ret->engine) {
149        ret->meth = ENGINE_get_DSA(ret->engine);
150        if (!ret->meth) {
151            DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
152            ENGINE_finish(ret->engine);
153            OPENSSL_free(ret);
154            return NULL;
155        }
156    }
157#endif
158
159    ret->pad = 0;
160    ret->version = 0;
161    ret->write_params = 1;
162    ret->p = NULL;
163    ret->q = NULL;
164    ret->g = NULL;
165
166    ret->pub_key = NULL;
167    ret->priv_key = NULL;
168
169    ret->kinv = NULL;
170    ret->r = NULL;
171    ret->method_mont_p = NULL;
172
173    ret->references = 1;
174    ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW;
175    CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
176    if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
177#ifndef OPENSSL_NO_ENGINE
178        if (ret->engine)
179            ENGINE_finish(ret->engine);
180#endif
181        CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
182        OPENSSL_free(ret);
183        ret = NULL;
184    }
185
186    return (ret);
187}
188
189void DSA_free(DSA *r)
190{
191    int i;
192
193    if (r == NULL)
194        return;
195
196    i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DSA);
197#ifdef REF_PRINT
198    REF_PRINT("DSA", r);
199#endif
200    if (i > 0)
201        return;
202#ifdef REF_CHECK
203    if (i < 0) {
204        fprintf(stderr, "DSA_free, bad reference count\n");
205        abort();
206    }
207#endif
208
209    if (r->meth->finish)
210        r->meth->finish(r);
211#ifndef OPENSSL_NO_ENGINE
212    if (r->engine)
213        ENGINE_finish(r->engine);
214#endif
215
216    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
217
218    if (r->p != NULL)
219        BN_clear_free(r->p);
220    if (r->q != NULL)
221        BN_clear_free(r->q);
222    if (r->g != NULL)
223        BN_clear_free(r->g);
224    if (r->pub_key != NULL)
225        BN_clear_free(r->pub_key);
226    if (r->priv_key != NULL)
227        BN_clear_free(r->priv_key);
228    if (r->kinv != NULL)
229        BN_clear_free(r->kinv);
230    if (r->r != NULL)
231        BN_clear_free(r->r);
232    OPENSSL_free(r);
233}
234
235int DSA_up_ref(DSA *r)
236{
237    int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA);
238#ifdef REF_PRINT
239    REF_PRINT("DSA", r);
240#endif
241#ifdef REF_CHECK
242    if (i < 2) {
243        fprintf(stderr, "DSA_up_ref, bad reference count\n");
244        abort();
245    }
246#endif
247    return ((i > 1) ? 1 : 0);
248}
249
250int DSA_size(const DSA *r)
251{
252    int ret, i;
253    ASN1_INTEGER bs;
254    unsigned char buf[4];       /* 4 bytes looks really small. However,
255                                 * i2d_ASN1_INTEGER() will not look beyond
256                                 * the first byte, as long as the second
257                                 * parameter is NULL. */
258
259    i = BN_num_bits(r->q);
260    bs.length = (i + 7) / 8;
261    bs.data = buf;
262    bs.type = V_ASN1_INTEGER;
263    /* If the top bit is set the asn1 encoding is 1 larger. */
264    buf[0] = 0xff;
265
266    i = i2d_ASN1_INTEGER(&bs, NULL);
267    i += i;                     /* r and s */
268    ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
269    return (ret);
270}
271
272int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
273                         CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
274{
275    return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp,
276                                   new_func, dup_func, free_func);
277}
278
279int DSA_set_ex_data(DSA *d, int idx, void *arg)
280{
281    return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
282}
283
284void *DSA_get_ex_data(DSA *d, int idx)
285{
286    return (CRYPTO_get_ex_data(&d->ex_data, idx));
287}
288
289#ifndef OPENSSL_NO_DH
290DH *DSA_dup_DH(const DSA *r)
291{
292    /*
293     * DSA has p, q, g, optional pub_key, optional priv_key. DH has p,
294     * optional length, g, optional pub_key, optional priv_key, optional q.
295     */
296
297    DH *ret = NULL;
298
299    if (r == NULL)
300        goto err;
301    ret = DH_new();
302    if (ret == NULL)
303        goto err;
304    if (r->p != NULL)
305        if ((ret->p = BN_dup(r->p)) == NULL)
306            goto err;
307    if (r->q != NULL) {
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