lib/libcrypto/ecdh/ech_lib.c

   1 /* $OpenBSD: ech_lib.c,v 1.14 2018/04/14 07:09:21 tb 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         ENGINE_finish(ecdh->engine);
 113         ecdh->engine = NULL;
 114 #endif
 115         ecdh->meth = meth;
 116         return 1;
 117 }
 118
 119 static ECDH_DATA *
 120 ECDH_DATA_new_method(ENGINE *engine)
 121 {
 122         ECDH_DATA *ret;
 123
 124         ret = malloc(sizeof(ECDH_DATA));
 125         if (ret == NULL) {
 126                 ECDHerror(ERR_R_MALLOC_FAILURE);
 127                 return (NULL);
 128         }
 129
 130         ret->init = NULL;
 131
 132         ret->meth = ECDH_get_default_method();
 133         ret->engine = engine;
 134 #ifndef OPENSSL_NO_ENGINE
 135         if (!ret->engine)
 136                 ret->engine = ENGINE_get_default_ECDH();
 137         if (ret->engine) {
 138                 ret->meth = ENGINE_get_ECDH(ret->engine);
 139                 if (ret->meth == NULL) {
 140                         ECDHerror(ERR_R_ENGINE_LIB);
 141                         ENGINE_finish(ret->engine);
 142                         free(ret);
 143                         return NULL;
 144                 }
 145         }
 146 #endif
 147
 148         ret->flags = ret->meth->flags;
 149         CRYPTO_new_ex_data(CRYPTO_EX_INDEX_ECDH, ret, &ret->ex_data);
 150         return (ret);
 151 }
 152
 153 static void *
 154 ecdh_data_new(void)
 155 {
 156         return (void *)ECDH_DATA_new_method(NULL);
 157 }
 158
 159 static void *
 160 ecdh_data_dup(void *data)
 161 {
 162         ECDH_DATA *r = (ECDH_DATA *)data;
 163
 164         /* XXX: dummy operation */
 165         if (r == NULL)
 166                 return NULL;
 167
 168         return (void *)ecdh_data_new();
 169 }
 170
 171 void
 172 ecdh_data_free(void *data)
 173 {
 174         ECDH_DATA *r = (ECDH_DATA *)data;
 175
 176 #ifndef OPENSSL_NO_ENGINE
 177         ENGINE_finish(r->engine);
 178 #endif
 179
 180         CRYPTO_free_ex_data(CRYPTO_EX_INDEX_ECDH, r, &r->ex_data);
 181
 182         freezero(r, sizeof(ECDH_DATA));
 183 }
 184
 185 ECDH_DATA *
 186 ecdh_check(EC_KEY *key)
 187 {
 188         ECDH_DATA *ecdh_data;
 189
 190         void *data = EC_KEY_get_key_method_data(key, ecdh_data_dup,
 191             ecdh_data_free, ecdh_data_free);
 192         if (data == NULL) {
 193                 ecdh_data = (ECDH_DATA *)ecdh_data_new();
 194                 if (ecdh_data == NULL)
 195                         return NULL;
 196                 data = EC_KEY_insert_key_method_data(key, (void *)ecdh_data,
 197                     ecdh_data_dup, ecdh_data_free, ecdh_data_free);
 198                 if (data != NULL) {
 199                         /* Another thread raced us to install the key_method
 200                          * data and won. */
 201                         ecdh_data_free(ecdh_data);
 202                         ecdh_data = (ECDH_DATA *)data;
 203                 }
 204         } else
 205                 ecdh_data = (ECDH_DATA *)data;
 206
 207         return ecdh_data;
 208 }
 209
 210 int
 211 ECDH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
 212     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
 213 {
 214         return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_ECDH, argl, argp,
 215             new_func, dup_func, free_func);
 216 }
 217
 218 int
 219 ECDH_set_ex_data(EC_KEY *d, int idx, void *arg)
 220 {
 221         ECDH_DATA *ecdh;
 222         ecdh = ecdh_check(d);
 223         if (ecdh == NULL)
 224                 return 0;
 225         return (CRYPTO_set_ex_data(&ecdh->ex_data, idx, arg));
 226 }
 227
 228 void *
 229 ECDH_get_ex_data(EC_KEY *d, int idx)
 230 {
 231         ECDH_DATA *ecdh;
 232         ecdh = ecdh_check(d);
 233         if (ecdh == NULL)
 234                 return NULL;
 235         return (CRYPTO_get_ex_data(&ecdh->ex_data, idx));
 236 }
 237
 238 int
 239 ECDH_size(const EC_KEY *d)
 240 {
 241         return ((EC_GROUP_get_degree(EC_KEY_get0_group(d)) + 7) / 8);
 242 }