lib/libcrypto/ecdsa/ecs_lib.c

   1 /* $OpenBSD: ecs_lib.c,v 1.11 2017/01/29 17:49:23 beck Exp $ */
   2 /* ====================================================================
   3  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in
  14  *    the documentation and/or other materials provided with the
  15  *    distribution.
  16  *
  17  * 3. All advertising materials mentioning features or use of this
  18  *    software must display the following acknowledgment:
  19  *    "This product includes software developed by the OpenSSL Project
  20  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  21  *
  22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  23  *    endorse or promote products derived from this software without
  24  *    prior written permission. For written permission, please contact
  25  *    openssl-core@OpenSSL.org.
  26  *
  27  * 5. Products derived from this software may not be called "OpenSSL"
  28  *    nor may "OpenSSL" appear in their names without prior written
  29  *    permission of the OpenSSL Project.
  30  *
  31  * 6. Redistributions of any form whatsoever must retain the following
  32  *    acknowledgment:
  33  *    "This product includes software developed by the OpenSSL Project
  34  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  47  * OF THE POSSIBILITY OF SUCH DAMAGE.
  48  * ====================================================================
  49  *
  50  * This product includes cryptographic software written by Eric Young
  51  * (eay@cryptsoft.com).  This product includes software written by Tim
  52  * Hudson (tjh@cryptsoft.com).
  53  *
  54  */
  55
  56 #include <string.h>
  57
  58 #include <openssl/opensslconf.h>
  59
  60 #include "ecs_locl.h"
  61 #ifndef OPENSSL_NO_ENGINE
  62 #include <openssl/engine.h>
  63 #endif
  64 #include <openssl/err.h>
  65 #include <openssl/bn.h>
  66
  67 static const ECDSA_METHOD *default_ECDSA_method = NULL;
  68
  69 static void *ecdsa_data_new(void);
  70 static void *ecdsa_data_dup(void *);
  71 static void  ecdsa_data_free(void *);
  72
  73 void
  74 ECDSA_set_default_method(const ECDSA_METHOD *meth)
  75 {
  76         default_ECDSA_method = meth;
  77 }
  78
  79 const ECDSA_METHOD *
  80 ECDSA_get_default_method(void)
  81 {
  82         if (!default_ECDSA_method) {
  83                 default_ECDSA_method = ECDSA_OpenSSL();
  84         }
  85         return default_ECDSA_method;
  86 }
  87
  88 int
  89 ECDSA_set_method(EC_KEY *eckey, const ECDSA_METHOD *meth)
  90 {
  91         ECDSA_DATA *ecdsa;
  92
  93         ecdsa = ecdsa_check(eckey);
  94
  95         if (ecdsa == NULL)
  96                 return 0;
  97
  98 #ifndef OPENSSL_NO_ENGINE
  99         if (ecdsa->engine) {
 100                 ENGINE_finish(ecdsa->engine);
 101                 ecdsa->engine = NULL;
 102         }
 103 #endif
 104         ecdsa->meth = meth;
 105
 106         return 1;
 107 }
 108
 109 static ECDSA_DATA *
 110 ECDSA_DATA_new_method(ENGINE *engine)
 111 {
 112         ECDSA_DATA *ret;
 113
 114         ret = malloc(sizeof(ECDSA_DATA));
 115         if (ret == NULL) {
 116                 ECDSAerror(ERR_R_MALLOC_FAILURE);
 117                 return (NULL);
 118         }
 119
 120         ret->init = NULL;
 121
 122         ret->meth = ECDSA_get_default_method();
 123         ret->engine = engine;
 124 #ifndef OPENSSL_NO_ENGINE
 125         if (!ret->engine)
 126                 ret->engine = ENGINE_get_default_ECDSA();
 127         if (ret->engine) {
 128                 ret->meth = ENGINE_get_ECDSA(ret->engine);
 129                 if (!ret->meth) {
 130                         ECDSAerror(ERR_R_ENGINE_LIB);
 131                         ENGINE_finish(ret->engine);
 132                         free(ret);
 133                         return NULL;
 134                 }
 135         }
 136 #endif
 137
 138         ret->flags = ret->meth->flags;
 139         CRYPTO_new_ex_data(CRYPTO_EX_INDEX_ECDSA, ret, &ret->ex_data);
 140         return (ret);
 141 }
 142
 143 static void *
 144 ecdsa_data_new(void)
 145 {
 146         return (void *)ECDSA_DATA_new_method(NULL);
 147 }
 148
 149 static void *
 150 ecdsa_data_dup(void *data)
 151 {
 152         ECDSA_DATA *r = (ECDSA_DATA *)data;
 153
 154         /* XXX: dummy operation */
 155         if (r == NULL)
 156                 return NULL;
 157
 158         return ecdsa_data_new();
 159 }
 160
 161 static void
 162 ecdsa_data_free(void *data)
 163 {
 164         ECDSA_DATA *r = (ECDSA_DATA *)data;
 165
 166 #ifndef OPENSSL_NO_ENGINE
 167         if (r->engine)
 168                 ENGINE_finish(r->engine);
 169 #endif
 170         CRYPTO_free_ex_data(CRYPTO_EX_INDEX_ECDSA, r, &r->ex_data);
 171
 172         explicit_bzero((void *)r, sizeof(ECDSA_DATA));
 173
 174         free(r);
 175 }
 176
 177 ECDSA_DATA *
 178 ecdsa_check(EC_KEY *key)
 179 {
 180         ECDSA_DATA *ecdsa_data;
 181
 182         void *data = EC_KEY_get_key_method_data(key, ecdsa_data_dup,
 183             ecdsa_data_free, ecdsa_data_free);
 184         if (data == NULL) {
 185                 ecdsa_data = (ECDSA_DATA *)ecdsa_data_new();
 186                 if (ecdsa_data == NULL)
 187                         return NULL;
 188                 data = EC_KEY_insert_key_method_data(key, (void *)ecdsa_data,
 189                     ecdsa_data_dup, ecdsa_data_free, ecdsa_data_free);
 190                 if (data != NULL) {
 191                         /* Another thread raced us to install the key_method
 192                          * data and won. */
 193                         ecdsa_data_free(ecdsa_data);
 194                         ecdsa_data = (ECDSA_DATA *)data;
 195                 }
 196         } else
 197                 ecdsa_data = (ECDSA_DATA *)data;
 198
 199         return ecdsa_data;
 200 }
 201
 202 int
 203 ECDSA_size(const EC_KEY *r)
 204 {
 205         int ret, i;
 206         ASN1_INTEGER bs;
 207         BIGNUM  *order = NULL;
 208         unsigned char buf[4];
 209         const EC_GROUP *group;
 210
 211         if (r == NULL)
 212                 return 0;
 213         group = EC_KEY_get0_group(r);
 214         if (group == NULL)
 215                 return 0;
 216
 217         if ((order = BN_new()) == NULL)
 218                 return 0;
 219         if (!EC_GROUP_get_order(group, order, NULL)) {
 220                 BN_clear_free(order);
 221                 return 0;
 222         }
 223         i = BN_num_bits(order);
 224         bs.length = (i + 7) / 8;
 225         bs.data = buf;
 226         bs.type = V_ASN1_INTEGER;
 227         /* If the top bit is set the asn1 encoding is 1 larger. */
 228         buf[0] = 0xff;
 229
 230         i = i2d_ASN1_INTEGER(&bs, NULL);
 231         i += i; /* r and s */
 232         ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
 233         BN_clear_free(order);
 234         return (ret);
 235 }
 236
 237 int
 238 ECDSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
 239     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
 240 {
 241         return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_ECDSA, argl, argp,
 242             new_func, dup_func, free_func);
 243 }
 244
 245 int
 246 ECDSA_set_ex_data(EC_KEY *d, int idx, void *arg)
 247 {
 248         ECDSA_DATA *ecdsa;
 249         ecdsa = ecdsa_check(d);
 250         if (ecdsa == NULL)
 251                 return 0;
 252         return (CRYPTO_set_ex_data(&ecdsa->ex_data, idx, arg));
 253 }
 254
 255 void *
 256 ECDSA_get_ex_data(EC_KEY *d, int idx)
 257 {
 258         ECDSA_DATA *ecdsa;
 259         ecdsa = ecdsa_check(d);
 260         if (ecdsa == NULL)
 261                 return NULL;
 262         return (CRYPTO_get_ex_data(&ecdsa->ex_data, idx));
 263 }