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  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
  60  * Portions originally developed by SUN MICROSYSTEMS, INC., and
  61  * contributed to the OpenSSL project.
  62  */
  63
  64 #include "ec_lcl.h"
  65 #include <openssl/err.h>
  66 #include <string.h>
  67
  68 EC_KEY *EC_KEY_new(void)
  69         {
  70         EC_KEY *ret;
  71
  72         ret=(EC_KEY *)OPENSSL_malloc(sizeof(EC_KEY));
  73         if (ret == NULL)
  74                 {
  75                 ECerr(EC_F_EC_NEW, ERR_R_MALLOC_FAILURE);
  76                 return(NULL);
  77                 }
  78
  79         ret->version = 1;
  80         ret->group   = NULL;
  81         ret->pub_key = NULL;
  82         ret->priv_key= NULL;
  83         ret->enc_flag= 0;
  84         ret->conv_form = POINT_CONVERSION_UNCOMPRESSED;
  85         ret->references= 1;
  86         ret->meth_data = NULL;
  87         return(ret);
  88         }
  89
  90
  91 void EC_KEY_free(EC_KEY *r)
  92         {
  93         int i;
  94
  95         if (r == NULL) return;
  96
  97         i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_EC);
  98 #ifdef REF_PRINT
  99         REF_PRINT("EC_KEY",r);
 100 #endif
 101         if (i > 0) return;
 102 #ifdef REF_CHECK
 103         if (i < 0)
 104                 {
 105                 fprintf(stderr,"EC_KEY_free, bad reference count\n");
 106                 abort();
 107                 }
 108 #endif
 109
 110         if (r->group    != NULL)
 111                 EC_GROUP_free(r->group);
 112         if (r->pub_key  != NULL)
 113                 EC_POINT_free(r->pub_key);
 114         if (r->priv_key != NULL)
 115                 BN_clear_free(r->priv_key);
 116
 117         if (r->meth_data && r->meth_data->finish)
 118                 r->meth_data->finish(r);
 119
 120         memset((void *)r, 0x0, sizeof(EC_KEY));
 121
 122         OPENSSL_free(r);
 123         }
 124
 125 EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src)
 126         {
 127         if (dest == NULL || src == NULL)
 128                 {
 129                 ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER);
 130                 return NULL;
 131                 }
 132         /* copy the parameters */
 133         if (src->group)
 134                 {
 135                 const EC_METHOD *meth = EC_GROUP_method_of(src->group);
 136                 /* clear the old group */
 137                 if (dest->group)
 138                         EC_GROUP_free(dest->group);
 139                 dest->group = EC_GROUP_new(meth);
 140                 if (dest->group == NULL)
 141                         return NULL;
 142                 if (!EC_GROUP_copy(dest->group, src->group))
 143                         return NULL;
 144                 }
 145         /*  copy the public key */
 146         if (src->pub_key && src->group)
 147                 {
 148                 if (dest->pub_key)
 149                         EC_POINT_free(dest->pub_key);
 150                 dest->pub_key = EC_POINT_new(src->group);
 151                 if (dest->pub_key == NULL)
 152                         return NULL;
 153                 if (!EC_POINT_copy(dest->pub_key, src->pub_key))
 154                         return NULL;
 155                 }
 156         /* copy the private key */
 157         if (src->priv_key)
 158                 {
 159                 if (dest->priv_key == NULL)
 160                         {
 161                         dest->priv_key = BN_new();
 162                         if (dest->priv_key == NULL)
 163                                 return NULL;
 164                         }
 165                 if (!BN_copy(dest->priv_key, src->priv_key))
 166                         return NULL;
 167                 }
 168         /* copy the rest */
 169         dest->enc_flag  = src->enc_flag;
 170         dest->conv_form = src->conv_form;
 171         dest->version   = src->version;
 172
 173         return dest;
 174         }
 175
 176 EC_KEY *EC_KEY_dup(const EC_KEY *eckey)
 177         {
 178         EC_KEY *ret = NULL;
 179         int     ok = 1;
 180
 181         ret = EC_KEY_new();
 182         if (ret == NULL)
 183                 return NULL;
 184         /* copy the parameters */
 185         if (eckey->group)
 186                 {
 187                 ret->group = EC_GROUP_dup(eckey->group);
 188                 if (ret->group == NULL)
 189                         ok = 0;
 190                 }
 191         /*  copy the public key */
 192         if (eckey->pub_key && eckey->group)
 193                 {
 194                 ret->pub_key = EC_POINT_dup(eckey->pub_key, eckey->group);
 195                 if (ret->pub_key == NULL)
 196                         ok = 0;
 197                 }
 198         /* copy the private key */
 199         if (eckey->priv_key)
 200                 {
 201                 ret->priv_key = BN_dup(ret->priv_key);
 202                 if (ret->priv_key == NULL)
 203                         ok = 0;
 204                 }
 205         /* copy the rest */
 206         ret->enc_flag  = eckey->enc_flag;
 207         ret->conv_form = eckey->conv_form;
 208         ret->version   = eckey->version;
 209
 210         if (!ok)
 211                 {
 212                 EC_KEY_free(ret);
 213                 ret = NULL;
 214                 }
 215
 216         return ret;
 217         }
 218
 219 int EC_KEY_up_ref(EC_KEY *r)
 220         {
 221         int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC);
 222 #ifdef REF_PRINT
 223         REF_PRINT("EC_KEY",r);
 224 #endif
 225 #ifdef REF_CHECK
 226         if (i < 2)
 227                 {
 228                 fprintf(stderr, "EC_KEY_up, bad reference count\n");
 229                 abort();
 230                 }
 231 #endif
 232         return ((i > 1) ? 1 : 0);
 233         }
 234
 235 int EC_KEY_generate_key(EC_KEY *eckey)
 236         {
 237         int     ok = 0;
 238         BN_CTX  *ctx = NULL;
 239         BIGNUM  *priv_key = NULL, *order = NULL;
 240         EC_POINT *pub_key = NULL;
 241
 242         if (!eckey || !eckey->group)
 243                 {
 244                 ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
 245                 return 0;
 246                 }
 247
 248         if ((order = BN_new()) == NULL) goto err;
 249         if ((ctx = BN_CTX_new()) == NULL) goto err;
 250
 251         if (eckey->priv_key == NULL)
 252                 {
 253                 priv_key = BN_new();
 254                 if (priv_key == NULL)
 255                         goto err;
 256                 }
 257         else
 258                 priv_key = eckey->priv_key;
 259
 260         if (!EC_GROUP_get_order(eckey->group, order, ctx))
 261                 goto err;
 262
 263         do
 264                 if (!BN_rand_range(priv_key, order))
 265                         goto err;
 266         while (BN_is_zero(priv_key));
 267
 268         if (eckey->pub_key == NULL)
 269                 {
 270                 pub_key = EC_POINT_new(eckey->group);
 271                 if (pub_key == NULL)
 272                         goto err;
 273                 }
 274         else
 275                 pub_key = eckey->pub_key;
 276
 277         if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
 278                 goto err;
 279
 280         eckey->priv_key = priv_key;
 281         eckey->pub_key  = pub_key;
 282
 283         ok=1;
 284
 285 err:
 286         if (order)
 287                 BN_free(order);
 288         if (pub_key  != NULL && eckey->pub_key  == NULL)
 289                 EC_POINT_free(pub_key);
 290         if (priv_key != NULL && eckey->priv_key == NULL)
 291                 BN_free(priv_key);
 292         if (ctx != NULL)
 293                 BN_CTX_free(ctx);
 294         return(ok);
 295         }
 296
 297 int EC_KEY_check_key(const EC_KEY *eckey)
 298         {
 299         int     ok   = 0;
 300         BN_CTX  *ctx = NULL;
 301         BIGNUM  *order  = NULL;
 302         EC_POINT *point = NULL;
 303
 304         if (!eckey || !eckey->group || !eckey->pub_key)
 305                 {
 306                 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
 307                 return 0;
 308                 }
 309
 310         if ((ctx = BN_CTX_new()) == NULL)
 311                 goto err;
 312         if ((order = BN_new()) == NULL)
 313                 goto err;
 314         if ((point = EC_POINT_new(eckey->group)) == NULL)
 315                 goto err;
 316
 317         /* testing whether the pub_key is on the elliptic curve */
 318         if (!EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx))
 319                 {
 320                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
 321                 goto err;
 322                 }
 323         /* testing whether pub_key * order is the point at infinity */
 324         if (!EC_GROUP_get_order(eckey->group, order, ctx))
 325                 {
 326                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
 327                 goto err;
 328                 }
 329         if (!EC_POINT_copy(point, eckey->pub_key))
 330                 {
 331                 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 332                 goto err;
 333                 }
 334         if (!EC_POINT_mul(eckey->group, point, order, NULL, NULL, ctx))
 335                 {
 336                 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 337                 goto err;
 338                 }
 339         if (!EC_POINT_is_at_infinity(eckey->group, point))
 340                 {
 341                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 342                 goto err;
 343                 }
 344         /* in case the priv_key is present :
 345          * check if generator * priv_key == pub_key
 346          */
 347         if (eckey->priv_key)
 348                 {
 349                 if (BN_cmp(eckey->priv_key, order) >= 0)
 350                         {
 351                         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 352                         goto err;
 353                         }
 354                 if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
 355                         NULL, NULL, ctx))
 356                         {
 357                         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 358                         goto err;
 359                         }
 360                 if (EC_POINT_cmp(eckey->group, point, eckey->pub_key,
 361                         ctx) != 0)
 362                         {
 363                         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY);
 364                         goto err;
 365                         }
 366                 }
 367         ok = 1;
 368 err:
 369         if (ctx   != NULL)
 370                 BN_CTX_free(ctx);
 371         if (order != NULL)
 372                 BN_free(order);
 373         if (point != NULL)
 374                 EC_POINT_free(point);
 375         return(ok);
 376         }