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) 1998-2005 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->method_data = NULL;
  88         return(ret);
  89         }
  90
  91 EC_KEY *EC_KEY_new_by_curve_name(int nid)
  92         {
  93         EC_KEY *ret = EC_KEY_new();
  94         if (ret == NULL)
  95                 return NULL;
  96         ret->group = EC_GROUP_new_by_curve_name(nid);
  97         if (ret->group == NULL)
  98                 {
  99                 EC_KEY_free(ret);
 100                 return NULL;
 101                 }
 102         return ret;
 103         }
 104
 105 void EC_KEY_free(EC_KEY *r)
 106         {
 107         int i;
 108
 109         if (r == NULL) return;
 110
 111         i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_EC);
 112 #ifdef REF_PRINT
 113         REF_PRINT("EC_KEY",r);
 114 #endif
 115         if (i > 0) return;
 116 #ifdef REF_CHECK
 117         if (i < 0)
 118                 {
 119                 fprintf(stderr,"EC_KEY_free, bad reference count\n");
 120                 abort();
 121                 }
 122 #endif
 123
 124         if (r->group    != NULL)
 125                 EC_GROUP_free(r->group);
 126         if (r->pub_key  != NULL)
 127                 EC_POINT_free(r->pub_key);
 128         if (r->priv_key != NULL)
 129                 BN_clear_free(r->priv_key);
 130
 131         EC_EX_DATA_free_all_data(&r->method_data);
 132
 133         OPENSSL_cleanse((void *)r, sizeof(EC_KEY));
 134
 135         OPENSSL_free(r);
 136         }
 137
 138 EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src)
 139         {
 140         EC_EXTRA_DATA *d;
 141
 142         if (dest == NULL || src == NULL)
 143                 {
 144                 ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER);
 145                 return NULL;
 146                 }
 147         /* copy the parameters */
 148         if (src->group)
 149                 {
 150                 const EC_METHOD *meth = EC_GROUP_method_of(src->group);
 151                 /* clear the old group */
 152                 if (dest->group)
 153                         EC_GROUP_free(dest->group);
 154                 dest->group = EC_GROUP_new(meth);
 155                 if (dest->group == NULL)
 156                         return NULL;
 157                 if (!EC_GROUP_copy(dest->group, src->group))
 158                         return NULL;
 159                 }
 160         /*  copy the public key */
 161         if (src->pub_key && src->group)
 162                 {
 163                 if (dest->pub_key)
 164                         EC_POINT_free(dest->pub_key);
 165                 dest->pub_key = EC_POINT_new(src->group);
 166                 if (dest->pub_key == NULL)
 167                         return NULL;
 168                 if (!EC_POINT_copy(dest->pub_key, src->pub_key))
 169                         return NULL;
 170                 }
 171         /* copy the private key */
 172         if (src->priv_key)
 173                 {
 174                 if (dest->priv_key == NULL)
 175                         {
 176                         dest->priv_key = BN_new();
 177                         if (dest->priv_key == NULL)
 178                                 return NULL;
 179                         }
 180                 if (!BN_copy(dest->priv_key, src->priv_key))
 181                         return NULL;
 182                 }
 183         /* copy method/extra data */
 184         EC_EX_DATA_free_all_data(&dest->method_data);
 185
 186         for (d = src->method_data; d != NULL; d = d->next)
 187                 {
 188                 void *t = d->dup_func(d->data);
 189
 190                 if (t == NULL)
 191                         return 0;
 192                 if (!EC_EX_DATA_set_data(&dest->method_data, t, d->dup_func, d->free_func, d->clear_free_func))
 193                         return 0;
 194                 }
 195
 196         /* copy the rest */
 197         dest->enc_flag  = src->enc_flag;
 198         dest->conv_form = src->conv_form;
 199         dest->version   = src->version;
 200
 201         return dest;
 202         }
 203
 204 EC_KEY *EC_KEY_dup(const EC_KEY *ec_key)
 205         {
 206         EC_KEY *ret = EC_KEY_new();
 207         if (ret == NULL)
 208                 return NULL;
 209         if (EC_KEY_copy(ret, ec_key) == NULL)
 210                 {
 211                 EC_KEY_free(ret);
 212                 return NULL;
 213                 }
 214         return ret;
 215         }
 216
 217 int EC_KEY_up_ref(EC_KEY *r)
 218         {
 219         int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC);
 220 #ifdef REF_PRINT
 221         REF_PRINT("EC_KEY",r);
 222 #endif
 223 #ifdef REF_CHECK
 224         if (i < 2)
 225                 {
 226                 fprintf(stderr, "EC_KEY_up, bad reference count\n");
 227                 abort();
 228                 }
 229 #endif
 230         return ((i > 1) ? 1 : 0);
 231         }
 232
 233 int EC_KEY_generate_key(EC_KEY *eckey)
 234         {
 235         int     ok = 0;
 236         BN_CTX  *ctx = NULL;
 237         BIGNUM  *priv_key = NULL, *order = NULL;
 238         EC_POINT *pub_key = NULL;
 239
 240         if (!eckey || !eckey->group)
 241                 {
 242                 ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
 243                 return 0;
 244                 }
 245
 246         if ((order = BN_new()) == NULL) goto err;
 247         if ((ctx = BN_CTX_new()) == NULL) goto err;
 248
 249         if (eckey->priv_key == NULL)
 250                 {
 251                 priv_key = BN_new();
 252                 if (priv_key == NULL)
 253                         goto err;
 254                 }
 255         else
 256                 priv_key = eckey->priv_key;
 257
 258         if (!EC_GROUP_get_order(eckey->group, order, ctx))
 259                 goto err;
 260
 261         do
 262                 if (!BN_rand_range(priv_key, order))
 263                         goto err;
 264         while (BN_is_zero(priv_key));
 265
 266         if (eckey->pub_key == NULL)
 267                 {
 268                 pub_key = EC_POINT_new(eckey->group);
 269                 if (pub_key == NULL)
 270                         goto err;
 271                 }
 272         else
 273                 pub_key = eckey->pub_key;
 274
 275         if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
 276                 goto err;
 277
 278         eckey->priv_key = priv_key;
 279         eckey->pub_key  = pub_key;
 280
 281         ok=1;
 282
 283 err:
 284         if (order)
 285                 BN_free(order);
 286         if (pub_key  != NULL && eckey->pub_key  == NULL)
 287                 EC_POINT_free(pub_key);
 288         if (priv_key != NULL && eckey->priv_key == NULL)
 289                 BN_free(priv_key);
 290         if (ctx != NULL)
 291                 BN_CTX_free(ctx);
 292         return(ok);
 293         }
 294
 295 int EC_KEY_check_key(const EC_KEY *eckey)
 296         {
 297         int     ok   = 0;
 298         BN_CTX  *ctx = NULL;
 299         const BIGNUM    *order  = NULL;
 300         EC_POINT *point = NULL;
 301
 302         if (!eckey || !eckey->group || !eckey->pub_key)
 303                 {
 304                 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
 305                 return 0;
 306                 }
 307
 308         if ((ctx = BN_CTX_new()) == NULL)
 309                 goto err;
 310         if ((point = EC_POINT_new(eckey->group)) == NULL)
 311                 goto err;
 312
 313         /* testing whether the pub_key is on the elliptic curve */
 314         if (!EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx))
 315                 {
 316                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
 317                 goto err;
 318                 }
 319         /* testing whether pub_key * order is the point at infinity */
 320         order = &eckey->group->order;
 321         if (BN_is_zero(order))
 322                 {
 323                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
 324                 goto err;
 325                 }
 326         if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx))
 327                 {
 328                 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 329                 goto err;
 330                 }
 331         if (!EC_POINT_is_at_infinity(eckey->group, point))
 332                 {
 333                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 334                 goto err;
 335                 }
 336         /* in case the priv_key is present :
 337          * check if generator * priv_key == pub_key
 338          */
 339         if (eckey->priv_key)
 340                 {
 341                 if (BN_cmp(eckey->priv_key, order) >= 0)
 342                         {
 343                         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 344                         goto err;
 345                         }
 346                 if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
 347                         NULL, NULL, ctx))
 348                         {
 349                         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 350                         goto err;
 351                         }
 352                 if (EC_POINT_cmp(eckey->group, point, eckey->pub_key,
 353                         ctx) != 0)
 354                         {
 355                         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY);
 356                         goto err;
 357                         }
 358                 }
 359         ok = 1;
 360 err:
 361         if (ctx   != NULL)
 362                 BN_CTX_free(ctx);
 363         if (point != NULL)
 364                 EC_POINT_free(point);
 365         return(ok);
 366         }
 367
 368 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key)
 369         {
 370         return key->group;
 371         }
 372
 373 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group)
 374         {
 375         if (key->group != NULL)
 376                 EC_GROUP_free(key->group);
 377         key->group = EC_GROUP_dup(group);
 378         return (key->group == NULL) ? 0 : 1;
 379         }
 380
 381 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key)
 382         {
 383         return key->priv_key;
 384         }
 385
 386 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key)
 387         {
 388         if (key->priv_key)
 389                 BN_clear_free(key->priv_key);
 390         key->priv_key = BN_dup(priv_key);
 391         return (key->priv_key == NULL) ? 0 : 1;
 392         }
 393
 394 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key)
 395         {
 396         return key->pub_key;
 397         }
 398
 399 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key)
 400         {
 401         if (key->pub_key != NULL)
 402                 EC_POINT_free(key->pub_key);
 403         key->pub_key = EC_POINT_dup(pub_key, key->group);
 404         return (key->pub_key == NULL) ? 0 : 1;
 405         }
 406
 407 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key)
 408         {
 409         return key->enc_flag;
 410         }
 411
 412 void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags)
 413         {
 414         key->enc_flag = flags;
 415         }
 416
 417 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key)
 418         {
 419         return key->conv_form;
 420         }
 421
 422 void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform)
 423         {
 424         key->conv_form = cform;
 425         if (key->group != NULL)
 426                 EC_GROUP_set_point_conversion_form(key->group, cform);
 427         }
 428
 429 void *EC_KEY_get_key_method_data(EC_KEY *key,
 430         void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
 431         {
 432         return EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
 433         }
 434
 435 void EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
 436         void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
 437         {
 438         EC_EXTRA_DATA *ex_data;
 439         CRYPTO_w_lock(CRYPTO_LOCK_EC);
 440         ex_data = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
 441         if (ex_data == NULL)
 442                 EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func, clear_free_func);
 443         CRYPTO_w_unlock(CRYPTO_LOCK_EC);
 444         }
 445
 446 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag)
 447         {
 448         if (key->group != NULL)
 449                 EC_GROUP_set_asn1_flag(key->group, flag);
 450         }
 451
 452 int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx)
 453         {
 454         if (key->group == NULL)
 455                 return 0;
 456         return EC_GROUP_precompute_mult(key->group, ctx);
 457         }