1/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2 * All rights reserved.
3 *
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
7 *
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to.  The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14 *
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the copyright
26 *    notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 *    notice, this list of conditions and the following disclaimer in the
29 *    documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 *    must display the following acknowledgement:
32 *    "This product includes cryptographic software written by
33 *     Eric Young (eay@cryptsoft.com)"
34 *    The word 'cryptographic' can be left out if the rouines from the library
35 *    being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 *    the apps directory (application code) you must include an acknowledgement:
38 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed.  i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.] */
56
57#include <openssl/dh.h>
58
59#include <openssl/bn.h>
60#include <openssl/buf.h>
61#include <openssl/err.h>
62#include <openssl/ex_data.h>
63#include <openssl/mem.h>
64#include <openssl/thread.h>
65
66#include "internal.h"
67
68
69extern const DH_METHOD DH_default_method;
70
71DH *DH_new(void) { return DH_new_method(NULL); }
72
73DH *DH_new_method(const ENGINE *engine) {
74  DH *dh = (DH *)OPENSSL_malloc(sizeof(DH));
75  if (dh == NULL) {
76    OPENSSL_PUT_ERROR(DH, DH_new_method, ERR_R_MALLOC_FAILURE);
77    return NULL;
78  }
79
80  memset(dh, 0, sizeof(DH));
81
82  if (engine) {
83    dh->meth = ENGINE_get_DH_method(engine);
84  }
85
86  if (dh->meth == NULL) {
87    dh->meth = (DH_METHOD*) &DH_default_method;
88  }
89  METHOD_ref(dh->meth);
90
91  dh->references = 1;
92  if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, dh, &dh->ex_data)) {
93    OPENSSL_free(dh);
94    return NULL;
95  }
96
97  if (dh->meth->init && !dh->meth->init(dh)) {
98    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, dh, &dh->ex_data);
99    METHOD_unref(dh->meth);
100    OPENSSL_free(dh);
101    return NULL;
102  }
103
104  return dh;
105}
106
107void DH_free(DH *dh) {
108  if (dh == NULL) {
109    return;
110  }
111
112  if (CRYPTO_add(&dh->references, -1, CRYPTO_LOCK_DH) > 0) {
113    return;
114  }
115
116  if (dh->meth->finish) {
117    dh->meth->finish(dh);
118  }
119  METHOD_unref(dh->meth);
120
121  CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, dh, &dh->ex_data);
122
123  if (dh->method_mont_p) BN_MONT_CTX_free(dh->method_mont_p);
124  if (dh->p != NULL) BN_clear_free(dh->p);
125  if (dh->g != NULL) BN_clear_free(dh->g);
126  if (dh->q != NULL) BN_clear_free(dh->q);
127  if (dh->j != NULL) BN_clear_free(dh->j);
128  if (dh->seed) OPENSSL_free(dh->seed);
129  if (dh->counter != NULL) BN_clear_free(dh->counter);
130  if (dh->pub_key != NULL) BN_clear_free(dh->pub_key);
131  if (dh->priv_key != NULL) BN_clear_free(dh->priv_key);
132
133  OPENSSL_free(dh);
134}
135
136int DH_generate_parameters_ex(DH *dh, int prime_bits, int generator, BN_GENCB *cb) {
137  if (dh->meth->generate_parameters) {
138    return dh->meth->generate_parameters(dh, prime_bits, generator, cb);
139  }
140  return DH_default_method.generate_parameters(dh, prime_bits, generator, cb);
141}
142
143int DH_generate_key(DH *dh) {
144  if (dh->meth->generate_key) {
145    return dh->meth->generate_key(dh);
146  }
147  return DH_default_method.generate_key(dh);
148}
149
150int DH_compute_key(unsigned char *out, const BIGNUM *peers_key, DH *dh) {
151  if (dh->meth->compute_key) {
152    return dh->meth->compute_key(dh, out, peers_key);
153  }
154  return DH_default_method.compute_key(dh, out, peers_key);
155}
156
157int DH_size(const DH *dh) { return BN_num_bytes(dh->p); }
158
159int DH_up_ref(DH *r) {
160  CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DH);
161  return 1;
162}
163
164static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src) {
165  BIGNUM *a = NULL;
166
167  if (src) {
168    a = BN_dup(src);
169    if (!a) {
170      return 0;
171    }
172  }
173
174  if (*dst) {
175    BN_free(*dst);
176  }
177  *dst = a;
178  return 1;
179}
180
181static int int_dh_param_copy(DH *to, const DH *from, int is_x942) {
182  if (is_x942 == -1) {
183    is_x942 = !!from->q;
184  }
185  if (!int_dh_bn_cpy(&to->p, from->p) ||
186      !int_dh_bn_cpy(&to->g, from->g)) {
187    return 0;
188  }
189
190  if (!is_x942) {
191    return 1;
192  }
193
194  if (!int_dh_bn_cpy(&to->q, from->q) ||
195      !int_dh_bn_cpy(&to->j, from->j)) {
196    return 0;
197  }
198
199  if (to->seed) {
200    OPENSSL_free(to->seed);
201    to->seed = NULL;
202    to->seedlen = 0;
203  }
204  if (from->seed) {
205    to->seed = BUF_memdup(from->seed, from->seedlen);
206    if (!to->seed) {
207      return 0;
208    }
209    to->seedlen = from->seedlen;
210  }
211
212  return 1;
213}
214
215DH *DHparams_dup(const DH *dh) {
216  DH *ret = DH_new();
217  if (!ret) {
218    return NULL;
219  }
220
221  if (!int_dh_param_copy(ret, dh, -1)) {
222    DH_free(ret);
223    return NULL;
224  }
225
226  return ret;
227}
228
229int DH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
230                        CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func) {
231  return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DH, argl, argp, new_func,
232                                 dup_func, free_func);
233}
234
235int DH_set_ex_data(DH *d, int idx, void *arg) {
236  return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
237}
238
239void *DH_get_ex_data(DH *d, int idx) {
240  return (CRYPTO_get_ex_data(&d->ex_data, idx));
241}
242