dh_lib.c revision 296465 
1/* crypto/dh/dh_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#include <stdio.h>
60#include "cryptlib.h"
61#include <openssl/bn.h>
62#include <openssl/dh.h>
63#ifndef OPENSSL_NO_ENGINE
64# include <openssl/engine.h>
65#endif
66
67const char DH_version[] = "Diffie-Hellman" OPENSSL_VERSION_PTEXT;
68
69static const DH_METHOD *default_DH_method = NULL;
70
71void DH_set_default_method(const DH_METHOD *meth)
72{
73    default_DH_method = meth;
74}
75
76const DH_METHOD *DH_get_default_method(void)
77{
78    if (!default_DH_method)
79        default_DH_method = DH_OpenSSL();
80    return default_DH_method;
81}
82
83int DH_set_method(DH *dh, const DH_METHOD *meth)
84{
85    /*
86     * NB: The caller is specifically setting a method, so it's not up to us
87     * to deal with which ENGINE it comes from.
88     */
89    const DH_METHOD *mtmp;
90    mtmp = dh->meth;
91    if (mtmp->finish)
92        mtmp->finish(dh);
93#ifndef OPENSSL_NO_ENGINE
94    if (dh->engine) {
95        ENGINE_finish(dh->engine);
96        dh->engine = NULL;
97    }
98#endif
99    dh->meth = meth;
100    if (meth->init)
101        meth->init(dh);
102    return 1;
103}
104
105DH *DH_new(void)
106{
107    return DH_new_method(NULL);
108}
109
110DH *DH_new_method(ENGINE *engine)
111{
112    DH *ret;
113
114    ret = (DH *)OPENSSL_malloc(sizeof(DH));
115    if (ret == NULL) {
116        DHerr(DH_F_DH_NEW_METHOD, ERR_R_MALLOC_FAILURE);
117        return (NULL);
118    }
119
120    ret->meth = DH_get_default_method();
121#ifndef OPENSSL_NO_ENGINE
122    if (engine) {
123        if (!ENGINE_init(engine)) {
124            DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
125            OPENSSL_free(ret);
126            return NULL;
127        }
128        ret->engine = engine;
129    } else
130        ret->engine = ENGINE_get_default_DH();
131    if (ret->engine) {
132        ret->meth = ENGINE_get_DH(ret->engine);
133        if (!ret->meth) {
134            DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
135            ENGINE_finish(ret->engine);
136            OPENSSL_free(ret);
137            return NULL;
138        }
139    }
140#endif
141
142    ret->pad = 0;
143    ret->version = 0;
144    ret->p = NULL;
145    ret->g = NULL;
146    ret->length = 0;
147    ret->pub_key = NULL;
148    ret->priv_key = NULL;
149    ret->q = NULL;
150    ret->j = NULL;
151    ret->seed = NULL;
152    ret->seedlen = 0;
153    ret->counter = NULL;
154    ret->method_mont_p = NULL;
155    ret->references = 1;
156    ret->flags = ret->meth->flags;
157    CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
158    if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
159#ifndef OPENSSL_NO_ENGINE
160        if (ret->engine)
161            ENGINE_finish(ret->engine);
162#endif
163        CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
164        OPENSSL_free(ret);
165        ret = NULL;
166    }
167    return (ret);
168}
169
170void DH_free(DH *r)
171{
172    int i;
173    if (r == NULL)
174        return;
175    i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DH);
176#ifdef REF_PRINT
177    REF_PRINT("DH", r);
178#endif
179    if (i > 0)
180        return;
181#ifdef REF_CHECK
182    if (i < 0) {
183        fprintf(stderr, "DH_free, bad reference count\n");
184        abort();
185    }
186#endif
187
188    if (r->meth->finish)
189        r->meth->finish(r);
190#ifndef OPENSSL_NO_ENGINE
191    if (r->engine)
192        ENGINE_finish(r->engine);
193#endif
194
195    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, r, &r->ex_data);
196
197    if (r->p != NULL)
198        BN_clear_free(r->p);
199    if (r->g != NULL)
200        BN_clear_free(r->g);
201    if (r->q != NULL)
202        BN_clear_free(r->q);
203    if (r->j != NULL)
204        BN_clear_free(r->j);
205    if (r->seed)
206        OPENSSL_free(r->seed);
207    if (r->counter != NULL)
208        BN_clear_free(r->counter);
209    if (r->pub_key != NULL)
210        BN_clear_free(r->pub_key);
211    if (r->priv_key != NULL)
212        BN_clear_free(r->priv_key);
213    OPENSSL_free(r);
214}
215
216int DH_up_ref(DH *r)
217{
218    int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DH);
219#ifdef REF_PRINT
220    REF_PRINT("DH", r);
221#endif
222#ifdef REF_CHECK
223    if (i < 2) {
224        fprintf(stderr, "DH_up, bad reference count\n");
225        abort();
226    }
227#endif
228    return ((i > 1) ? 1 : 0);
229}
230
231int DH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
232                        CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
233{
234    return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DH, argl, argp,
235                                   new_func, dup_func, free_func);
236}
237
238int DH_set_ex_data(DH *d, int idx, void *arg)
239{
240    return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
241}
242
243void *DH_get_ex_data(DH *d, int idx)
244{
245    return (CRYPTO_get_ex_data(&d->ex_data, idx));
246}
247
248int DH_size(const DH *dh)
249{
250    return (BN_num_bytes(dh->p));
251}
252