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 <string.h>
  65 #include "ec_lcl.h"
  66 #include <openssl/err.h>
  67 #include <string.h>
  68
  69 EC_KEY *EC_KEY_new(void)
  70         {
  71         EC_KEY *ret;
  72
  73         ret=(EC_KEY *)OPENSSL_malloc(sizeof(EC_KEY));
  74         if (ret == NULL)
  75                 {
  76                 ECerr(EC_F_EC_KEY_NEW, ERR_R_MALLOC_FAILURE);
  77                 return(NULL);
  78                 }
  79
  80         ret->version = 1;
  81         ret->group   = NULL;
  82         ret->pub_key = NULL;
  83         ret->priv_key= NULL;
  84         ret->enc_flag= 0;
  85         ret->conv_form = POINT_CONVERSION_UNCOMPRESSED;
  86         ret->references= 1;
  87         ret->meth_data = NULL;
  88         return(ret);
  89         }
  90
  91
  92 void EC_KEY_free(EC_KEY *r)
  93         {
  94         int i;
  95
  96         if (r == NULL) return;
  97
  98         i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_EC);
  99 #ifdef REF_PRINT
 100         REF_PRINT("EC_KEY",r);
 101 #endif
 102         if (i > 0) return;
 103 #ifdef REF_CHECK
 104         if (i < 0)
 105                 {
 106                 fprintf(stderr,"EC_KEY_free, bad reference count\n");
 107                 abort();
 108                 }
 109 #endif
 110
 111         if (r->group    != NULL)
 112                 EC_GROUP_free(r->group);
 113         if (r->pub_key  != NULL)
 114                 EC_POINT_free(r->pub_key);
 115         if (r->priv_key != NULL)
 116                 BN_clear_free(r->priv_key);
 117
 118         if (r->meth_data && r->meth_data->finish)
 119                 r->meth_data->finish(r);
 120
 121         OPENSSL_cleanse((void *)r, sizeof(EC_KEY));
 122
 123         OPENSSL_free(r);
 124         }
 125
 126 EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src)
 127         {
 128         if (dest == NULL || src == NULL)
 129                 {
 130                 ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER);
 131                 return NULL;
 132                 }
 133         /* copy the parameters */
 134         if (src->group)
 135                 {
 136                 const EC_METHOD *meth = EC_GROUP_method_of(src->group);
 137                 /* clear the old group */
 138                 if (dest->group)
 139                         EC_GROUP_free(dest->group);
 140                 dest->group = EC_GROUP_new(meth);
 141                 if (dest->group == NULL)
 142                         return NULL;
 143                 if (!EC_GROUP_copy(dest->group, src->group))
 144                         return NULL;
 145                 }
 146         /*  copy the public key */
 147         if (src->pub_key && src->group)
 148                 {
 149                 if (dest->pub_key)
 150                         EC_POINT_free(dest->pub_key);
 151                 dest->pub_key = EC_POINT_new(src->group);
 152                 if (dest->pub_key == NULL)
 153                         return NULL;
 154                 if (!EC_POINT_copy(dest->pub_key, src->pub_key))
 155                         return NULL;
 156                 }
 157         /* copy the private key */
 158         if (src->priv_key)
 159                 {
 160                 if (dest->priv_key == NULL)
 161                         {
 162                         dest->priv_key = BN_new();
 163                         if (dest->priv_key == NULL)
 164                                 return NULL;
 165                         }
 166                 if (!BN_copy(dest->priv_key, src->priv_key))
 167                         return NULL;
 168                 }
 169         /* copy the rest */
 170         dest->enc_flag  = src->enc_flag;
 171         dest->conv_form = src->conv_form;
 172         dest->version   = src->version;
 173
 174         return dest;
 175         }
 176
 177 EC_KEY *EC_KEY_dup(const EC_KEY *eckey)
 178         {
 179         EC_KEY *ret = NULL;
 180         int     ok = 1;
 181
 182         ret = EC_KEY_new();
 183         if (ret == NULL)
 184                 return NULL;
 185         /* copy the parameters */
 186         if (eckey->group)
 187                 {
 188                 ret->group = EC_GROUP_dup(eckey->group);
 189                 if (ret->group == NULL)
 190                         ok = 0;
 191                 }
 192         /*  copy the public key */
 193         if (eckey->pub_key && eckey->group)
 194                 {
 195                 ret->pub_key = EC_POINT_dup(eckey->pub_key, eckey->group);
 196                 if (ret->pub_key == NULL)
 197                         ok = 0;
 198                 }
 199         /* copy the private key */
 200         if (eckey->priv_key)
 201                 {
 202                 ret->priv_key = BN_dup(eckey->priv_key);
 203                 if (ret->priv_key == NULL)
 204                         ok = 0;
 205                 }
 206         /* copy the rest */
 207         ret->enc_flag  = eckey->enc_flag;
 208         ret->conv_form = eckey->conv_form;
 209         ret->version   = eckey->version;
 210
 211         if (!ok)
 212                 {
 213                 EC_KEY_free(ret);
 214                 ret = NULL;
 215                 }
 216
 217         return ret;
 218         }
 219
 220 int EC_KEY_up_ref(EC_KEY *r)
 221         {
 222         int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC);
 223 #ifdef REF_PRINT
 224         REF_PRINT("EC_KEY",r);
 225 #endif
 226 #ifdef REF_CHECK
 227         if (i < 2)
 228                 {
 229                 fprintf(stderr, "EC_KEY_up, bad reference count\n");
 230                 abort();
 231                 }
 232 #endif
 233         return ((i > 1) ? 1 : 0);
 234         }
 235
 236 int EC_KEY_generate_key(EC_KEY *eckey)
 237         {
 238         int     ok = 0;
 239         BN_CTX  *ctx = NULL;
 240         BIGNUM  *priv_key = NULL, *order = NULL;
 241         EC_POINT *pub_key = NULL;
 242
 243         if (!eckey || !eckey->group)
 244                 {
 245                 ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
 246                 return 0;
 247                 }
 248
 249         if ((order = BN_new()) == NULL) goto err;
 250         if ((ctx = BN_CTX_new()) == NULL) goto err;
 251
 252         if (eckey->priv_key == NULL)
 253                 {
 254                 priv_key = BN_new();
 255                 if (priv_key == NULL)
 256                         goto err;
 257                 }
 258         else
 259                 priv_key = eckey->priv_key;
 260
 261         if (!EC_GROUP_get_order(eckey->group, order, ctx))
 262                 goto err;
 263
 264         do
 265                 if (!BN_rand_range(priv_key, order))
 266                         goto err;
 267         while (BN_is_zero(priv_key));
 268
 269         if (eckey->pub_key == NULL)
 270                 {
 271                 pub_key = EC_POINT_new(eckey->group);
 272                 if (pub_key == NULL)
 273                         goto err;
 274                 }
 275         else
 276                 pub_key = eckey->pub_key;
 277
 278         if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
 279                 goto err;
 280
 281         eckey->priv_key = priv_key;
 282         eckey->pub_key  = pub_key;
 283
 284         ok=1;
 285
 286 err:
 287         if (order)
 288                 BN_free(order);
 289         if (pub_key  != NULL && eckey->pub_key  == NULL)
 290                 EC_POINT_free(pub_key);
 291         if (priv_key != NULL && eckey->priv_key == NULL)
 292                 BN_free(priv_key);
 293         if (ctx != NULL)
 294                 BN_CTX_free(ctx);
 295         return(ok);
 296         }
 297
 298 int EC_KEY_check_key(const EC_KEY *eckey)
 299         {
 300         int     ok   = 0;
 301         BN_CTX  *ctx = NULL;
 302         BIGNUM  *order  = NULL;
 303         EC_POINT *point = NULL;
 304
 305         if (!eckey || !eckey->group || !eckey->pub_key)
 306                 {
 307                 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
 308                 return 0;
 309                 }
 310
 311         if ((ctx = BN_CTX_new()) == NULL)
 312                 goto err;
 313         if ((order = BN_new()) == NULL)
 314                 goto err;
 315         if ((point = EC_POINT_new(eckey->group)) == NULL)
 316                 goto err;
 317
 318         /* testing whether the pub_key is on the elliptic curve */
 319         if (!EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx))
 320                 {
 321                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
 322                 goto err;
 323                 }
 324         /* testing whether pub_key * order is the point at infinity */
 325         if (!EC_GROUP_get_order(eckey->group, order, ctx))
 326                 {
 327                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
 328                 goto err;
 329                 }
 330         if (!EC_POINT_copy(point, eckey->pub_key))
 331                 {
 332                 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 333                 goto err;
 334                 }
 335         if (!EC_POINT_mul(eckey->group, point, order, NULL, NULL, ctx))
 336                 {
 337                 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 338                 goto err;
 339                 }
 340         if (!EC_POINT_is_at_infinity(eckey->group, point))
 341                 {
 342                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 343                 goto err;
 344                 }
 345         /* in case the priv_key is present :
 346          * check if generator * priv_key == pub_key
 347          */
 348         if (eckey->priv_key)
 349                 {
 350                 if (BN_cmp(eckey->priv_key, order) >= 0)
 351                         {
 352                         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 353                         goto err;
 354                         }
 355                 if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
 356                         NULL, NULL, ctx))
 357                         {
 358                         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 359                         goto err;
 360                         }
 361                 if (EC_POINT_cmp(eckey->group, point, eckey->pub_key,
 362                         ctx) != 0)
 363                         {
 364                         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY);
 365                         goto err;
 366                         }
 367                 }
 368         ok = 1;
 369 err:
 370         if (ctx   != NULL)
 371                 BN_CTX_free(ctx);
 372         if (order != NULL)
 373                 BN_free(order);
 374         if (point != NULL)
 375                 EC_POINT_free(point);
 376         return(ok);
 377         }