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 <string.h>
60 
61 #include <openssl/bn.h>
62 #include <openssl/buf.h>
63 #include <openssl/err.h>
64 #include <openssl/ex_data.h>
65 #include <openssl/mem.h>
66 #include <openssl/thread.h>
67 
68 #include "internal.h"
69 #include "../internal.h"
70 
71 
72 extern const DH_METHOD DH_default_method;
73 
74 static CRYPTO_EX_DATA_CLASS g_ex_data_class = CRYPTO_EX_DATA_CLASS_INIT;
75 
DH_new(void)76 DH *DH_new(void) { return DH_new_method(NULL); }
77 
DH_new_method(const ENGINE * engine)78 DH *DH_new_method(const ENGINE *engine) {
79   DH *dh = (DH *)OPENSSL_malloc(sizeof(DH));
80   if (dh == NULL) {
81     OPENSSL_PUT_ERROR(DH, DH_new_method, ERR_R_MALLOC_FAILURE);
82     return NULL;
83   }
84 
85   memset(dh, 0, sizeof(DH));
86 
87   if (engine) {
88     dh->meth = ENGINE_get_DH_method(engine);
89   }
90 
91   if (dh->meth == NULL) {
92     dh->meth = (DH_METHOD*) &DH_default_method;
93   }
94   METHOD_ref(dh->meth);
95 
96   CRYPTO_MUTEX_init(&dh->method_mont_p_lock);
97 
98   dh->references = 1;
99   if (!CRYPTO_new_ex_data(&g_ex_data_class, dh, &dh->ex_data)) {
100     OPENSSL_free(dh);
101     return NULL;
102   }
103 
104   if (dh->meth->init && !dh->meth->init(dh)) {
105     CRYPTO_free_ex_data(&g_ex_data_class, dh, &dh->ex_data);
106     METHOD_unref(dh->meth);
107     OPENSSL_free(dh);
108     return NULL;
109   }
110 
111   return dh;
112 }
113 
DH_free(DH * dh)114 void DH_free(DH *dh) {
115   if (dh == NULL) {
116     return;
117   }
118 
119   if (!CRYPTO_refcount_dec_and_test_zero(&dh->references)) {
120     return;
121   }
122 
123   if (dh->meth->finish) {
124     dh->meth->finish(dh);
125   }
126   METHOD_unref(dh->meth);
127 
128   CRYPTO_free_ex_data(&g_ex_data_class, dh, &dh->ex_data);
129 
130   if (dh->method_mont_p) BN_MONT_CTX_free(dh->method_mont_p);
131   if (dh->p != NULL) BN_clear_free(dh->p);
132   if (dh->g != NULL) BN_clear_free(dh->g);
133   if (dh->q != NULL) BN_clear_free(dh->q);
134   if (dh->j != NULL) BN_clear_free(dh->j);
135   if (dh->seed) OPENSSL_free(dh->seed);
136   if (dh->counter != NULL) BN_clear_free(dh->counter);
137   if (dh->pub_key != NULL) BN_clear_free(dh->pub_key);
138   if (dh->priv_key != NULL) BN_clear_free(dh->priv_key);
139   CRYPTO_MUTEX_cleanup(&dh->method_mont_p_lock);
140 
141   OPENSSL_free(dh);
142 }
143 
DH_generate_parameters_ex(DH * dh,int prime_bits,int generator,BN_GENCB * cb)144 int DH_generate_parameters_ex(DH *dh, int prime_bits, int generator, BN_GENCB *cb) {
145   if (dh->meth->generate_parameters) {
146     return dh->meth->generate_parameters(dh, prime_bits, generator, cb);
147   }
148   return DH_default_method.generate_parameters(dh, prime_bits, generator, cb);
149 }
150 
DH_generate_key(DH * dh)151 int DH_generate_key(DH *dh) {
152   if (dh->meth->generate_key) {
153     return dh->meth->generate_key(dh);
154   }
155   return DH_default_method.generate_key(dh);
156 }
157 
DH_compute_key(unsigned char * out,const BIGNUM * peers_key,DH * dh)158 int DH_compute_key(unsigned char *out, const BIGNUM *peers_key, DH *dh) {
159   if (dh->meth->compute_key) {
160     return dh->meth->compute_key(dh, out, peers_key);
161   }
162   return DH_default_method.compute_key(dh, out, peers_key);
163 }
164 
DH_size(const DH * dh)165 int DH_size(const DH *dh) { return BN_num_bytes(dh->p); }
166 
DH_num_bits(const DH * dh)167 unsigned DH_num_bits(const DH *dh) { return BN_num_bits(dh->p); }
168 
DH_up_ref(DH * dh)169 int DH_up_ref(DH *dh) {
170   CRYPTO_refcount_inc(&dh->references);
171   return 1;
172 }
173 
int_dh_bn_cpy(BIGNUM ** dst,const BIGNUM * src)174 static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src) {
175   BIGNUM *a = NULL;
176 
177   if (src) {
178     a = BN_dup(src);
179     if (!a) {
180       return 0;
181     }
182   }
183 
184   BN_free(*dst);
185   *dst = a;
186   return 1;
187 }
188 
int_dh_param_copy(DH * to,const DH * from,int is_x942)189 static int int_dh_param_copy(DH *to, const DH *from, int is_x942) {
190   if (is_x942 == -1) {
191     is_x942 = !!from->q;
192   }
193   if (!int_dh_bn_cpy(&to->p, from->p) ||
194       !int_dh_bn_cpy(&to->g, from->g)) {
195     return 0;
196   }
197 
198   if (!is_x942) {
199     return 1;
200   }
201 
202   if (!int_dh_bn_cpy(&to->q, from->q) ||
203       !int_dh_bn_cpy(&to->j, from->j)) {
204     return 0;
205   }
206 
207   OPENSSL_free(to->seed);
208   to->seed = NULL;
209   to->seedlen = 0;
210 
211   if (from->seed) {
212     to->seed = BUF_memdup(from->seed, from->seedlen);
213     if (!to->seed) {
214       return 0;
215     }
216     to->seedlen = from->seedlen;
217   }
218 
219   return 1;
220 }
221 
DHparams_dup(const DH * dh)222 DH *DHparams_dup(const DH *dh) {
223   DH *ret = DH_new();
224   if (!ret) {
225     return NULL;
226   }
227 
228   if (!int_dh_param_copy(ret, dh, -1)) {
229     DH_free(ret);
230     return NULL;
231   }
232 
233   return ret;
234 }
235 
DH_get_ex_new_index(long argl,void * argp,CRYPTO_EX_new * new_func,CRYPTO_EX_dup * dup_func,CRYPTO_EX_free * free_func)236 int DH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
237                         CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func) {
238   int index;
239   if (!CRYPTO_get_ex_new_index(&g_ex_data_class, &index, argl, argp, new_func,
240                                dup_func, free_func)) {
241     return -1;
242   }
243   return index;
244 }
245 
DH_set_ex_data(DH * d,int idx,void * arg)246 int DH_set_ex_data(DH *d, int idx, void *arg) {
247   return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
248 }
249 
DH_get_ex_data(DH * d,int idx)250 void *DH_get_ex_data(DH *d, int idx) {
251   return (CRYPTO_get_ex_data(&d->ex_data, idx));
252 }
253