xref: /openbsd-src/lib/libcrypto/dh/dh_lib.c (revision c3d6a26af7455bccce87985ff78ef0efc39b65e1)
1 /* $OpenBSD: dh_lib.c,v 1.15 2014/06/12 15:49:28 deraadt 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 #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 
67 const char DH_version[]="Diffie-Hellman" OPENSSL_VERSION_PTEXT;
68 
69 static const DH_METHOD *default_DH_method = NULL;
70 
71 void DH_set_default_method(const DH_METHOD *meth)
72 	{
73 	default_DH_method = meth;
74 	}
75 
76 const DH_METHOD *DH_get_default_method(void)
77 	{
78 	if(!default_DH_method)
79 		{
80 		default_DH_method = DH_OpenSSL();
81 		}
82 	return default_DH_method;
83 	}
84 
85 int DH_set_method(DH *dh, const DH_METHOD *meth)
86 	{
87 	/* NB: The caller is specifically setting a method, so it's not up to us
88 	 * to deal with which ENGINE it comes from. */
89         const DH_METHOD *mtmp;
90         mtmp = dh->meth;
91         if (mtmp->finish) mtmp->finish(dh);
92 #ifndef OPENSSL_NO_ENGINE
93 	if (dh->engine)
94 		{
95 		ENGINE_finish(dh->engine);
96 		dh->engine = NULL;
97 		}
98 #endif
99         dh->meth = meth;
100         if (meth->init) meth->init(dh);
101         return 1;
102 	}
103 
104 DH *DH_new(void)
105 	{
106 	return DH_new_method(NULL);
107 	}
108 
109 DH *DH_new_method(ENGINE *engine)
110 	{
111 	DH *ret;
112 
113 	ret = malloc(sizeof(DH));
114 	if (ret == NULL)
115 		{
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 		{
124 		if (!ENGINE_init(engine))
125 			{
126 			DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
127 			free(ret);
128 			return NULL;
129 			}
130 		ret->engine = engine;
131 		}
132 	else
133 		ret->engine = ENGINE_get_default_DH();
134 	if(ret->engine)
135 		{
136 		ret->meth = ENGINE_get_DH(ret->engine);
137 		if(!ret->meth)
138 			{
139 			DHerr(DH_F_DH_NEW_METHOD,ERR_R_ENGINE_LIB);
140 			ENGINE_finish(ret->engine);
141 			free(ret);
142 			return NULL;
143 			}
144 		}
145 #endif
146 
147 	ret->pad=0;
148 	ret->version=0;
149 	ret->p=NULL;
150 	ret->g=NULL;
151 	ret->length=0;
152 	ret->pub_key=NULL;
153 	ret->priv_key=NULL;
154 	ret->q=NULL;
155 	ret->j=NULL;
156 	ret->seed = NULL;
157 	ret->seedlen = 0;
158 	ret->counter = NULL;
159 	ret->method_mont_p=NULL;
160 	ret->references = 1;
161 	ret->flags=ret->meth->flags & ~DH_FLAG_NON_FIPS_ALLOW;
162 	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
163 	if ((ret->meth->init != NULL) && !ret->meth->init(ret))
164 		{
165 #ifndef OPENSSL_NO_ENGINE
166 		if (ret->engine)
167 			ENGINE_finish(ret->engine);
168 #endif
169 		CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
170 		free(ret);
171 		ret=NULL;
172 		}
173 	return(ret);
174 	}
175 
176 void DH_free(DH *r)
177 	{
178 	int i;
179 	if(r == NULL) return;
180 	i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DH);
181 	if (i > 0) return;
182 
183 	if (r->meth->finish)
184 		r->meth->finish(r);
185 #ifndef OPENSSL_NO_ENGINE
186 	if (r->engine)
187 		ENGINE_finish(r->engine);
188 #endif
189 
190 	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, r, &r->ex_data);
191 
192 	if (r->p != NULL) BN_clear_free(r->p);
193 	if (r->g != NULL) BN_clear_free(r->g);
194 	if (r->q != NULL) BN_clear_free(r->q);
195 	if (r->j != NULL) BN_clear_free(r->j);
196 	free(r->seed);
197 	if (r->counter != NULL) BN_clear_free(r->counter);
198 	if (r->pub_key != NULL) BN_clear_free(r->pub_key);
199 	if (r->priv_key != NULL) BN_clear_free(r->priv_key);
200 	free(r);
201 	}
202 
203 int DH_up_ref(DH *r)
204 	{
205 	int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DH);
206 	return ((i > 1) ? 1 : 0);
207 	}
208 
209 int DH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
210 	     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
211         {
212 	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DH, argl, argp,
213 				new_func, dup_func, free_func);
214         }
215 
216 int DH_set_ex_data(DH *d, int idx, void *arg)
217 	{
218 	return(CRYPTO_set_ex_data(&d->ex_data,idx,arg));
219 	}
220 
221 void *DH_get_ex_data(DH *d, int idx)
222 	{
223 	return(CRYPTO_get_ex_data(&d->ex_data,idx));
224 	}
225 
226 int DH_size(const DH *dh)
227 	{
228 	return(BN_num_bytes(dh->p));
229 	}
230