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
  65
  66 #include <string.h>
  67 #include "ec_lcl.h"
  68 #include <openssl/err.h>
  69
  70 EC_KEY *EC_KEY_new(void)
  71         {
  72         EC_KEY *ret;
  73
  74         ret=(EC_KEY *)OPENSSL_malloc(sizeof(EC_KEY));
  75         if (ret == NULL)
  76                 {
  77                 ECerr(EC_F_EC_KEY_NEW, ERR_R_MALLOC_FAILURE);
  78                 return(NULL);
  79                 }
  80
  81         ret->version = 1;
  82         ret->flags = 0;
  83         ret->group   = NULL;
  84         ret->pub_key = NULL;
  85         ret->priv_key= NULL;
  86         ret->enc_flag= 0;
  87         ret->conv_form = POINT_CONVERSION_UNCOMPRESSED;
  88         ret->references= 1;
  89         ret->method_data = NULL;
  90         return(ret);
  91         }
  92
  93 EC_KEY *EC_KEY_new_by_curve_name(int nid)
  94         {
  95         EC_KEY *ret = EC_KEY_new();
  96         if (ret == NULL)
  97                 return NULL;
  98         ret->group = EC_GROUP_new_by_curve_name(nid);
  99         if (ret->group == NULL)
 100                 {
 101                 EC_KEY_free(ret);
 102                 return NULL;
 103                 }
 104         return ret;
 105         }
 106
 107 void EC_KEY_free(EC_KEY *r)
 108         {
 109         int i;
 110
 111         if (r == NULL) return;
 112
 113         i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_EC);
 114 #ifdef REF_PRINT
 115         REF_PRINT("EC_KEY",r);
 116 #endif
 117         if (i > 0) return;
 118 #ifdef REF_CHECK
 119         if (i < 0)
 120                 {
 121                 fprintf(stderr,"EC_KEY_free, bad reference count\n");
 122                 abort();
 123                 }
 124 #endif
 125
 126         if (r->group    != NULL)
 127                 EC_GROUP_free(r->group);
 128         if (r->pub_key  != NULL)
 129                 EC_POINT_free(r->pub_key);
 130         if (r->priv_key != NULL)
 131                 BN_clear_free(r->priv_key);
 132
 133         EC_EX_DATA_free_all_data(&r->method_data);
 134
 135         OPENSSL_cleanse((void *)r, sizeof(EC_KEY));
 136
 137         OPENSSL_free(r);
 138         }
 139
 140 EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src)
 141         {
 142         EC_EXTRA_DATA *d;
 143
 144         if (dest == NULL || src == NULL)
 145                 {
 146                 ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER);
 147                 return NULL;
 148                 }
 149         /* copy the parameters */
 150         if (src->group)
 151                 {
 152                 const EC_METHOD *meth = EC_GROUP_method_of(src->group);
 153                 /* clear the old group */
 154                 if (dest->group)
 155                         EC_GROUP_free(dest->group);
 156                 dest->group = EC_GROUP_new(meth);
 157                 if (dest->group == NULL)
 158                         return NULL;
 159                 if (!EC_GROUP_copy(dest->group, src->group))
 160                         return NULL;
 161                 }
 162         /*  copy the public key */
 163         if (src->pub_key && src->group)
 164                 {
 165                 if (dest->pub_key)
 166                         EC_POINT_free(dest->pub_key);
 167                 dest->pub_key = EC_POINT_new(src->group);
 168                 if (dest->pub_key == NULL)
 169                         return NULL;
 170                 if (!EC_POINT_copy(dest->pub_key, src->pub_key))
 171                         return NULL;
 172                 }
 173         /* copy the private key */
 174         if (src->priv_key)
 175                 {
 176                 if (dest->priv_key == NULL)
 177                         {
 178                         dest->priv_key = BN_new();
 179                         if (dest->priv_key == NULL)
 180                                 return NULL;
 181                         }
 182                 if (!BN_copy(dest->priv_key, src->priv_key))
 183                         return NULL;
 184                 }
 185         /* copy method/extra data */
 186         EC_EX_DATA_free_all_data(&dest->method_data);
 187
 188         for (d = src->method_data; d != NULL; d = d->next)
 189                 {
 190                 void *t = d->dup_func(d->data);
 191
 192                 if (t == NULL)
 193                         return 0;
 194                 if (!EC_EX_DATA_set_data(&dest->method_data, t, d->dup_func, d->free_func, d->clear_free_func))
 195                         return 0;
 196                 }
 197
 198         /* copy the rest */
 199         dest->enc_flag  = src->enc_flag;
 200         dest->conv_form = src->conv_form;
 201         dest->version   = src->version;
 202         dest->flags = src->flags;
 203
 204         return dest;
 205         }
 206
 207 EC_KEY *EC_KEY_dup(const EC_KEY *ec_key)
 208         {
 209         EC_KEY *ret = EC_KEY_new();
 210         if (ret == NULL)
 211                 return NULL;
 212         if (EC_KEY_copy(ret, ec_key) == NULL)
 213                 {
 214                 EC_KEY_free(ret);
 215                 return NULL;
 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         const 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 (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key))
 312                 {
 313                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_AT_INFINITY);
 314                 goto err;
 315                 }
 316
 317         if ((ctx = BN_CTX_new()) == NULL)
 318                 goto err;
 319         if ((point = EC_POINT_new(eckey->group)) == NULL)
 320                 goto err;
 321
 322         /* testing whether the pub_key is on the elliptic curve */
 323         if (!EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx))
 324                 {
 325                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
 326                 goto err;
 327                 }
 328         /* testing whether pub_key * order is the point at infinity */
 329         order = &eckey->group->order;
 330         if (BN_is_zero(order))
 331                 {
 332                 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
 333                 goto err;
 334                 }
 335         if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, 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 (point != NULL)
 373                 EC_POINT_free(point);
 374         return(ok);
 375         }
 376
 377 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x, BIGNUM *y)
 378         {
 379         BN_CTX *ctx = NULL;
 380         BIGNUM *tx, *ty;
 381         EC_POINT *point = NULL;
 382         int ok = 0, tmp_nid, is_char_two = 0;
 383
 384         if (!key || !key->group || !x || !y)
 385                 {
 386                 ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
 387                                                 ERR_R_PASSED_NULL_PARAMETER);
 388                 return 0;
 389                 }
 390         ctx = BN_CTX_new();
 391         if (!ctx)
 392                 goto err;
 393
 394         point = EC_POINT_new(key->group);
 395
 396         if (!point)
 397                 goto err;
 398
 399         tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group));
 400
 401         if (tmp_nid == NID_X9_62_characteristic_two_field)
 402                 is_char_two = 1;
 403
 404         tx = BN_CTX_get(ctx);
 405         ty = BN_CTX_get(ctx);
 406 #ifndef OPENSSL_NO_EC2M
 407         if (is_char_two)
 408                 {
 409                 if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point,
 410                                                                 x, y, ctx))
 411                         goto err;
 412                 if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point,
 413                                                                 tx, ty, ctx))
 414                         goto err;
 415                 }
 416         else
 417 #endif
 418                 {
 419                 if (!EC_POINT_set_affine_coordinates_GFp(key->group, point,
 420                                                                 x, y, ctx))
 421                         goto err;
 422                 if (!EC_POINT_get_affine_coordinates_GFp(key->group, point,
 423                                                                 tx, ty, ctx))
 424                         goto err;
 425                 }
 426         /* Check if retrieved coordinates match originals and are less than
 427          * field order: if not values are out of range.
 428          */
 429         if (BN_cmp(x, tx) || BN_cmp(y, ty)
 430                 || (BN_cmp(x, &key->group->field) >= 0)
 431                 || (BN_cmp(y, &key->group->field) >= 0))
 432                 {
 433                 ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
 434                         EC_R_COORDINATES_OUT_OF_RANGE);
 435                 goto err;
 436                 }
 437
 438         if (!EC_KEY_set_public_key(key, point))
 439                 goto err;
 440
 441         if (EC_KEY_check_key(key) == 0)
 442                 goto err;
 443
 444         ok = 1;
 445
 446         err:
 447         if (ctx)
 448                 BN_CTX_free(ctx);
 449         if (point)
 450                 EC_POINT_free(point);
 451         return ok;
 452
 453         }
 454
 455 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key)
 456         {
 457         return key->group;
 458         }
 459
 460 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group)
 461         {
 462         if (key->group != NULL)
 463                 EC_GROUP_free(key->group);
 464         key->group = EC_GROUP_dup(group);
 465         return (key->group == NULL) ? 0 : 1;
 466         }
 467
 468 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key)
 469         {
 470         return key->priv_key;
 471         }
 472
 473 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key)
 474         {
 475         if (key->priv_key)
 476                 BN_clear_free(key->priv_key);
 477         key->priv_key = BN_dup(priv_key);
 478         return (key->priv_key == NULL) ? 0 : 1;
 479         }
 480
 481 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key)
 482         {
 483         return key->pub_key;
 484         }
 485
 486 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key)
 487         {
 488         if (key->pub_key != NULL)
 489                 EC_POINT_free(key->pub_key);
 490         key->pub_key = EC_POINT_dup(pub_key, key->group);
 491         return (key->pub_key == NULL) ? 0 : 1;
 492         }
 493
 494 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key)
 495         {
 496         return key->enc_flag;
 497         }
 498
 499 void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags)
 500         {
 501         key->enc_flag = flags;
 502         }
 503
 504 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key)
 505         {
 506         return key->conv_form;
 507         }
 508
 509 void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform)
 510         {
 511         key->conv_form = cform;
 512         if (key->group != NULL)
 513                 EC_GROUP_set_point_conversion_form(key->group, cform);
 514         }
 515
 516 void *EC_KEY_get_key_method_data(EC_KEY *key,
 517         void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
 518         {
 519         void *ret;
 520
 521         CRYPTO_r_lock(CRYPTO_LOCK_EC);
 522         ret = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
 523         CRYPTO_r_unlock(CRYPTO_LOCK_EC);
 524
 525         return ret;
 526         }
 527
 528 void *EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
 529         void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
 530         {
 531         EC_EXTRA_DATA *ex_data;
 532
 533         CRYPTO_w_lock(CRYPTO_LOCK_EC);
 534         ex_data = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
 535         if (ex_data == NULL)
 536                 EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func, clear_free_func);
 537         CRYPTO_w_unlock(CRYPTO_LOCK_EC);
 538
 539         return ex_data;
 540         }
 541
 542 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag)
 543         {
 544         if (key->group != NULL)
 545                 EC_GROUP_set_asn1_flag(key->group, flag);
 546         }
 547
 548 int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx)
 549         {
 550         if (key->group == NULL)
 551                 return 0;
 552         return EC_GROUP_precompute_mult(key->group, ctx);
 553         }
 554
 555 int EC_KEY_get_flags(const EC_KEY *key)
 556         {
 557         return key->flags;
 558         }
 559
 560 void EC_KEY_set_flags(EC_KEY *key, int flags)
 561         {
 562         key->flags |= flags;
 563         }
 564
 565 void EC_KEY_clear_flags(EC_KEY *key, int flags)
 566         {
 567         key->flags &= ~flags;
 568         }