1 /* $OpenBSD: ech_lib.c,v 1.10 2015/09/13 10:46:20 jsing Exp $ */
2 /* ====================================================================
3  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
4  *
5  * The Elliptic Curve Public-Key Crypto Library (ECC Code) included
6  * herein is developed by SUN MICROSYSTEMS, INC., and is contributed
7  * to the OpenSSL project.
8  *
9  * The ECC Code is licensed pursuant to the OpenSSL open source
10  * license provided below.
11  *
12  * The ECDH software is originally written by Douglas Stebila of
13  * Sun Microsystems Laboratories.
14  *
15  */
16 /* ====================================================================
17  * Copyright (c) 1998-2003 The OpenSSL Project.  All rights reserved.
18  *
19  * Redistribution and use in source and binary forms, with or without
20  * modification, are permitted provided that the following conditions
21  * are met:
22  *
23  * 1. Redistributions of source code must retain the above copyright
24  *    notice, this list of conditions and the following disclaimer.
25  *
26  * 2. Redistributions in binary form must reproduce the above copyright
27  *    notice, this list of conditions and the following disclaimer in
28  *    the documentation and/or other materials provided with the
29  *    distribution.
30  *
31  * 3. All advertising materials mentioning features or use of this
32  *    software must display the following acknowledgment:
33  *    "This product includes software developed by the OpenSSL Project
34  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
35  *
36  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
37  *    endorse or promote products derived from this software without
38  *    prior written permission. For written permission, please contact
39  *    openssl-core@OpenSSL.org.
40  *
41  * 5. Products derived from this software may not be called "OpenSSL"
42  *    nor may "OpenSSL" appear in their names without prior written
43  *    permission of the OpenSSL Project.
44  *
45  * 6. Redistributions of any form whatsoever must retain the following
46  *    acknowledgment:
47  *    "This product includes software developed by the OpenSSL Project
48  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
51  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
53  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
54  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
55  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
56  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
57  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
59  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
60  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
61  * OF THE POSSIBILITY OF SUCH DAMAGE.
62  * ====================================================================
63  *
64  * This product includes cryptographic software written by Eric Young
65  * (eay@cryptsoft.com).  This product includes software written by Tim
66  * Hudson (tjh@cryptsoft.com).
67  *
68  */
69 
70 #include <string.h>
71 
72 #include <openssl/opensslconf.h>
73 
74 #include "ech_locl.h"
75 #ifndef OPENSSL_NO_ENGINE
76 #include <openssl/engine.h>
77 #endif
78 #include <openssl/err.h>
79 
80 static const ECDH_METHOD *default_ECDH_method = NULL;
81 
82 static void *ecdh_data_new(void);
83 static void *ecdh_data_dup(void *);
84 static void  ecdh_data_free(void *);
85 
86 void
87 ECDH_set_default_method(const ECDH_METHOD *meth)
88 {
89 	default_ECDH_method = meth;
90 }
91 
92 const ECDH_METHOD *
93 ECDH_get_default_method(void)
94 {
95 	if (!default_ECDH_method) {
96 		default_ECDH_method = ECDH_OpenSSL();
97 	}
98 	return default_ECDH_method;
99 }
100 
101 int
102 ECDH_set_method(EC_KEY *eckey, const ECDH_METHOD *meth)
103 {
104 	ECDH_DATA *ecdh;
105 
106 	ecdh = ecdh_check(eckey);
107 
108 	if (ecdh == NULL)
109 		return 0;
110 
111 #ifndef OPENSSL_NO_ENGINE
112 	if (ecdh->engine) {
113 		ENGINE_finish(ecdh->engine);
114 		ecdh->engine = NULL;
115 	}
116 #endif
117 	ecdh->meth = meth;
118 	return 1;
119 }
120 
121 static ECDH_DATA *
122 ECDH_DATA_new_method(ENGINE *engine)
123 {
124 	ECDH_DATA *ret;
125 
126 	ret = malloc(sizeof(ECDH_DATA));
127 	if (ret == NULL) {
128 		ECDHerr(ECDH_F_ECDH_DATA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
129 		return (NULL);
130 	}
131 
132 	ret->init = NULL;
133 
134 	ret->meth = ECDH_get_default_method();
135 	ret->engine = engine;
136 #ifndef OPENSSL_NO_ENGINE
137 	if (!ret->engine)
138 		ret->engine = ENGINE_get_default_ECDH();
139 	if (ret->engine) {
140 		ret->meth = ENGINE_get_ECDH(ret->engine);
141 		if (!ret->meth) {
142 			ECDHerr(ECDH_F_ECDH_DATA_NEW_METHOD, ERR_R_ENGINE_LIB);
143 			ENGINE_finish(ret->engine);
144 			free(ret);
145 			return NULL;
146 		}
147 	}
148 #endif
149 
150 	ret->flags = ret->meth->flags;
151 	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_ECDH, ret, &ret->ex_data);
152 	return (ret);
153 }
154 
155 static void *
156 ecdh_data_new(void)
157 {
158 	return (void *)ECDH_DATA_new_method(NULL);
159 }
160 
161 static void *
162 ecdh_data_dup(void *data)
163 {
164 	ECDH_DATA *r = (ECDH_DATA *)data;
165 
166 	/* XXX: dummy operation */
167 	if (r == NULL)
168 		return NULL;
169 
170 	return (void *)ecdh_data_new();
171 }
172 
173 void
174 ecdh_data_free(void *data)
175 {
176 	ECDH_DATA *r = (ECDH_DATA *)data;
177 
178 #ifndef OPENSSL_NO_ENGINE
179 	if (r->engine)
180 		ENGINE_finish(r->engine);
181 #endif
182 
183 	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_ECDH, r, &r->ex_data);
184 
185 	explicit_bzero((void *)r, sizeof(ECDH_DATA));
186 
187 	free(r);
188 }
189 
190 ECDH_DATA *
191 ecdh_check(EC_KEY *key)
192 {
193 	ECDH_DATA *ecdh_data;
194 
195 	void *data = EC_KEY_get_key_method_data(key, ecdh_data_dup,
196 	    ecdh_data_free, ecdh_data_free);
197 	if (data == NULL) {
198 		ecdh_data = (ECDH_DATA *)ecdh_data_new();
199 		if (ecdh_data == NULL)
200 			return NULL;
201 		data = EC_KEY_insert_key_method_data(key, (void *)ecdh_data,
202 		    ecdh_data_dup, ecdh_data_free, ecdh_data_free);
203 		if (data != NULL) {
204 			/* Another thread raced us to install the key_method
205 			 * data and won. */
206 			ecdh_data_free(ecdh_data);
207 			ecdh_data = (ECDH_DATA *)data;
208 		}
209 	} else
210 		ecdh_data = (ECDH_DATA *)data;
211 
212 	return ecdh_data;
213 }
214 
215 int
216 ECDH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
217     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
218 {
219 	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_ECDH, argl, argp,
220 	    new_func, dup_func, free_func);
221 }
222 
223 int
224 ECDH_set_ex_data(EC_KEY *d, int idx, void *arg)
225 {
226 	ECDH_DATA *ecdh;
227 	ecdh = ecdh_check(d);
228 	if (ecdh == NULL)
229 		return 0;
230 	return (CRYPTO_set_ex_data(&ecdh->ex_data, idx, arg));
231 }
232 
233 void *
234 ECDH_get_ex_data(EC_KEY *d, int idx)
235 {
236 	ECDH_DATA *ecdh;
237 	ecdh = ecdh_check(d);
238 	if (ecdh == NULL)
239 		return NULL;
240 	return (CRYPTO_get_ex_data(&ecdh->ex_data, idx));
241 }
242 
243 int
244 ECDH_size(const EC_KEY *d)
245 {
246 	return ((EC_GROUP_get_degree(EC_KEY_get0_group(d)) + 7) / 8);
247 }
248