crypto/ec/ec_key.c

   1 /* crypto/ec/ec_key.c */
   2 /*
   3  * Written by Nils Larsch for the OpenSSL project.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    openssl-core@openssl.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59 #include "ec_lcl.h"
  60 #include <openssl/err.h>
  61
  62 EC_KEY *EC_KEY_new(void)
  63         {
  64         EC_KEY *ret;
  65
  66         ret=(EC_KEY *)OPENSSL_malloc(sizeof(EC_KEY));
  67         if (ret == NULL)
  68                 {
  69                 ECerr(EC_F_EC_NEW, ERR_R_MALLOC_FAILURE);
  70                 return(NULL);
  71                 }
  72
  73         ret->version = 1;
  74         ret->group   = NULL;
  75         ret->pub_key = NULL;
  76         ret->priv_key= NULL;
  77         ret->enc_flag= 0;
  78         ret->conv_form = POINT_CONVERSION_UNCOMPRESSED;
  79         ret->references= 1;
  80         ret->meth_data = NULL;
  81         return(ret);
  82         }
  83
  84
  85 void EC_KEY_free(EC_KEY *r)
  86         {
  87         int i;
  88
  89         if (r == NULL) return;
  90
  91         i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_EC);
  92 #ifdef REF_PRINT
  93         REF_PRINT("EC_KEY",r);
  94 #endif
  95         if (i > 0) return;
  96 #ifdef REF_CHECK
  97         if (i < 0)
  98                 {
  99                 fprintf(stderr,"EC_KEY_free, bad reference count\n");
 100                 abort();
 101                 }
 102 #endif
 103
 104         if (r->group    != NULL)
 105                 EC_GROUP_free(r->group);
 106         if (r->pub_key  != NULL)
 107                 EC_POINT_free(r->pub_key);
 108         if (r->priv_key != NULL)
 109                 BN_clear_free(r->priv_key);
 110
 111         if (r->meth_data && r->meth_data->finish)
 112                 r->meth_data->finish(r);
 113
 114         memset((void *)r, 0x0, sizeof(EC_KEY));
 115
 116         OPENSSL_free(r);
 117         }
 118
 119 EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src)
 120         {
 121         if (dest == NULL || src == NULL)
 122                 {
 123                 ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER);
 124                 return NULL;
 125                 }
 126         /* copy the parameters */
 127         if (src->group)
 128                 {
 129                 const EC_METHOD *meth = EC_GROUP_method_of(src->group);
 130                 /* clear the old group */
 131                 if (dest->group)
 132                         EC_GROUP_free(dest->group);
 133                 dest->group = EC_GROUP_new(meth);
 134                 if (dest->group == NULL)
 135                         return NULL;
 136                 if (!EC_GROUP_copy(dest->group, src->group))
 137                         return NULL;
 138                 }
 139         /*  copy the public key */
 140         if (src->pub_key && src->group)
 141                 {
 142                 if (dest->pub_key)
 143                         EC_POINT_free(dest->pub_key);
 144                 dest->pub_key = EC_POINT_new(src->group);
 145                 if (dest->pub_key == NULL)
 146                         return NULL;
 147                 if (!EC_POINT_copy(dest->pub_key, src->pub_key))
 148                         return NULL;
 149                 }
 150         /* copy the private key */
 151         if (src->priv_key)
 152                 {
 153                 if (dest->priv_key == NULL)
 154                         {
 155                         dest->priv_key = BN_new();
 156                         if (dest->priv_key == NULL)
 157                                 return NULL;
 158                         }
 159                 if (!BN_copy(dest->priv_key, src->priv_key))
 160                         return NULL;
 161                 }
 162         /* copy the rest */
 163         dest->enc_flag  = src->enc_flag;
 164         dest->conv_form = src->conv_form;
 165         dest->version   = src->version;
 166
 167         return dest;
 168         }
 169
 170 EC_KEY *EC_KEY_dup(const EC_KEY *eckey)
 171         {
 172         EC_KEY *ret = NULL;
 173         int     ok = 1;
 174
 175         ret = EC_KEY_new();
 176         if (ret == NULL)
 177                 return NULL;
 178         /* copy the parameters */
 179         if (eckey->group)
 180                 {
 181                 ret->group = EC_GROUP_dup(eckey->group);
 182                 if (ret->group == NULL)
 183                         ok = 0;
 184                 }
 185         /*  copy the public key */
 186         if (eckey->pub_key && eckey->group)
 187                 {
 188                 ret->pub_key = EC_POINT_dup(eckey->pub_key, eckey->group);
 189                 if (ret->pub_key == NULL)
 190                         ok = 0;
 191                 }
 192         /* copy the private key */
 193         if (eckey->priv_key)
 194                 {
 195                 ret->priv_key = BN_dup(ret->priv_key);
 196                 if (ret->priv_key == NULL)
 197                         ok = 0;
 198                 }
 199         /* copy the rest */
 200         ret->enc_flag  = eckey->enc_flag;
 201         ret->conv_form = eckey->conv_form;
 202         ret->version   = eckey->version;
 203
 204         if (!ok)
 205                 {
 206                 EC_KEY_free(ret);
 207                 ret = NULL;
 208                 }
 209
 210         return ret;
 211         }
 212
 213 int EC_KEY_generate_key(EC_KEY *eckey)
 214         {
 215         int     ok = 0;
 216         BN_CTX  *ctx = NULL;
 217         BIGNUM  *priv_key = NULL, *order = NULL;
 218         EC_POINT *pub_key = NULL;
 219
 220         if (!eckey || !eckey->group)
 221                 {
 222                 ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
 223                 return 0;
 224                 }
 225
 226         if ((order = BN_new()) == NULL) goto err;
 227         if ((ctx = BN_CTX_new()) == NULL) goto err;
 228
 229         if (eckey->priv_key == NULL)
 230                 {
 231                 priv_key = BN_new();
 232                 if (priv_key == NULL)
 233                         goto err;
 234                 }
 235         else
 236                 priv_key = eckey->priv_key;
 237
 238         if (!EC_GROUP_get_order(eckey->group, order, ctx))
 239                 goto err;
 240
 241         do
 242                 if (!BN_rand_range(priv_key, order))
 243                         goto err;
 244         while (BN_is_zero(priv_key));
 245
 246         if (eckey->pub_key == NULL)
 247                 {
 248                 pub_key = EC_POINT_new(eckey->group);
 249                 if (pub_key == NULL)
 250                         goto err;
 251                 }
 252         else
 253                 pub_key = eckey->pub_key;
 254
 255         if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
 256                 goto err;
 257
 258         eckey->priv_key = priv_key;
 259         eckey->pub_key  = pub_key;
 260
 261         ok=1;
 262
 263 err:
 264         if (order)
 265                 BN_free(order);
 266         if (pub_key  != NULL && eckey->pub_key  == NULL)
 267                 EC_POINT_free(pub_key);
 268         if (priv_key != NULL && eckey->priv_key == NULL)
 269                 BN_free(priv_key);
 270         if (ctx != NULL)
 271                 BN_CTX_free(ctx);
 272         return(ok);
 273         }
 274
 275 int EC_KEY_check_key(const EC_KEY *eckey)
 276         {
 277         int     ok   = 0;
 278         BN_CTX  *ctx = NULL;
 279         BIGNUM  *order  = NULL;
 280         EC_POINT *point = NULL;
 281
 282         if (!eckey || !eckey->group || !eckey->pub_key)
 283                 {
 284                 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
 285                 return 0;
 286                 }
 287
 288         if ((ctx = BN_CTX_new()) == NULL)
 289                 goto err;
 290         if ((order = BN_new()) == NULL)
 291                 goto err;
 292         if ((point = EC_POINT_new(eckey->group)) == NULL)
 293                 goto err;
 294
 295         /* testing whether the pub_key is on the elliptic curve */
 296         if (!EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx))
 297                 {
 298                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
 299                 goto err;
 300                 }
 301         /* testing whether pub_key * order is the point at infinity */
 302         if (!EC_GROUP_get_order(eckey->group, order, ctx))
 303                 {
 304                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
 305                 goto err;
 306                 }
 307         if (!EC_POINT_copy(point, eckey->pub_key))
 308                 {
 309                 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 310                 goto err;
 311                 }
 312         if (!EC_POINT_mul(eckey->group, point, order, NULL, NULL, ctx))
 313                 {
 314                 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 315                 goto err;
 316                 }
 317         if (!EC_POINT_is_at_infinity(eckey->group, point))
 318                 {
 319                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 320                 goto err;
 321                 }
 322         /* in case the priv_key is present :
 323          * check if generator * priv_key == pub_key
 324          */
 325         if (eckey->priv_key)
 326                 {
 327                 if (BN_cmp(eckey->priv_key, order) >= 0)
 328                         {
 329                         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 330                         goto err;
 331                         }
 332                 if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
 333                         NULL, NULL, ctx))
 334                         {
 335                         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 336                         goto err;
 337                         }
 338                 if (EC_POINT_cmp(eckey->group, point, eckey->pub_key,
 339                         ctx) != 0)
 340                         {
 341                         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY);
 342                         goto err;
 343                         }
 344                 }
 345         ok = 1;
 346 err:
 347         if (ctx   != NULL)
 348                 BN_CTX_free(ctx);
 349         if (order != NULL)
 350                 BN_free(order);
 351         if (point != NULL)
 352                 EC_POINT_free(point);
 353         return(ok);
 354         }