xref: /openbsd/lib/libcrypto/dh/dh_lib.c (revision a6445c1d)
1 /* $OpenBSD: dh_lib.c,v 1.20 2014/07/12 16:03:37 miod Exp $ */
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 
61 #include <openssl/opensslconf.h>
62 
63 #include <openssl/bn.h>
64 #include <openssl/dh.h>
65 
66 #ifndef OPENSSL_NO_ENGINE
67 #include <openssl/engine.h>
68 #endif
69 
70 static const DH_METHOD *default_DH_method = NULL;
71 
72 void
73 DH_set_default_method(const DH_METHOD *meth)
74 {
75 	default_DH_method = meth;
76 }
77 
78 const DH_METHOD *
79 DH_get_default_method(void)
80 {
81 	if (!default_DH_method)
82 		default_DH_method = DH_OpenSSL();
83 	return default_DH_method;
84 }
85 
86 int
87 DH_set_method(DH *dh, const DH_METHOD *meth)
88 {
89 	/*
90 	 * NB: The caller is specifically setting a method, so it's not up to us
91 	 * to deal with which ENGINE it comes from.
92 	 */
93         const DH_METHOD *mtmp;
94 
95         mtmp = dh->meth;
96         if (mtmp->finish)
97 		mtmp->finish(dh);
98 #ifndef OPENSSL_NO_ENGINE
99 	if (dh->engine) {
100 		ENGINE_finish(dh->engine);
101 		dh->engine = NULL;
102 	}
103 #endif
104         dh->meth = meth;
105         if (meth->init)
106 		meth->init(dh);
107         return 1;
108 }
109 
110 DH *
111 DH_new(void)
112 {
113 	return DH_new_method(NULL);
114 }
115 
116 DH *
117 DH_new_method(ENGINE *engine)
118 {
119 	DH *ret;
120 
121 	ret = malloc(sizeof(DH));
122 	if (ret == NULL) {
123 		DHerr(DH_F_DH_NEW_METHOD, ERR_R_MALLOC_FAILURE);
124 		return NULL;
125 	}
126 
127 	ret->meth = DH_get_default_method();
128 #ifndef OPENSSL_NO_ENGINE
129 	if (engine) {
130 		if (!ENGINE_init(engine)) {
131 			DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
132 			free(ret);
133 			return NULL;
134 		}
135 		ret->engine = engine;
136 	} else
137 		ret->engine = ENGINE_get_default_DH();
138 	if(ret->engine) {
139 		ret->meth = ENGINE_get_DH(ret->engine);
140 		if (!ret->meth) {
141 			DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
142 			ENGINE_finish(ret->engine);
143 			free(ret);
144 			return NULL;
145 		}
146 	}
147 #endif
148 
149 	ret->pad = 0;
150 	ret->version = 0;
151 	ret->p = NULL;
152 	ret->g = NULL;
153 	ret->length = 0;
154 	ret->pub_key = NULL;
155 	ret->priv_key = NULL;
156 	ret->q = NULL;
157 	ret->j = NULL;
158 	ret->seed = NULL;
159 	ret->seedlen = 0;
160 	ret->counter = NULL;
161 	ret->method_mont_p=NULL;
162 	ret->references = 1;
163 	ret->flags = ret->meth->flags & ~DH_FLAG_NON_FIPS_ALLOW;
164 	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
165 	if (ret->meth->init != NULL && !ret->meth->init(ret)) {
166 #ifndef OPENSSL_NO_ENGINE
167 		if (ret->engine)
168 			ENGINE_finish(ret->engine);
169 #endif
170 		CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
171 		free(ret);
172 		ret = NULL;
173 	}
174 	return ret;
175 }
176 
177 void
178 DH_free(DH *r)
179 {
180 	int i;
181 
182 	if (r == NULL)
183 		return;
184 	i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DH);
185 	if (i > 0)
186 		return;
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 	BN_clear_free(r->p);
198 	BN_clear_free(r->g);
199 	BN_clear_free(r->q);
200 	BN_clear_free(r->j);
201 	free(r->seed);
202 	BN_clear_free(r->counter);
203 	BN_clear_free(r->pub_key);
204 	BN_clear_free(r->priv_key);
205 	free(r);
206 }
207 
208 int
209 DH_up_ref(DH *r)
210 {
211 	int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DH);
212 
213 	return i > 1 ? 1 : 0;
214 }
215 
216 int
217 DH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
218     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
219 {
220 	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DH, argl, argp, new_func,
221 	    dup_func, free_func);
222 }
223 
224 int
225 DH_set_ex_data(DH *d, int idx, void *arg)
226 {
227 	return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
228 }
229 
230 void *
231 DH_get_ex_data(DH *d, int idx)
232 {
233 	return CRYPTO_get_ex_data(&d->ex_data, idx);
234 }
235 
236 int
237 DH_size(const DH *dh)
238 {
239 	return BN_num_bytes(dh->p);
240 }
241