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
  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         ECerr(EC_F_EC_KEY_NEW, ERR_R_MALLOC_FAILURE);
  75         return (NULL);
  76     }
  77
  78     ret->version = 1;
  79     ret->flags = 0;
  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->method_data = NULL;
  87     return (ret);
  88 }
  89
  90 EC_KEY *EC_KEY_new_by_curve_name(int nid)
  91 {
  92     EC_KEY *ret = EC_KEY_new();
  93     if (ret == NULL)
  94         return NULL;
  95     ret->group = EC_GROUP_new_by_curve_name(nid);
  96     if (ret->group == NULL) {
  97         EC_KEY_free(ret);
  98         return NULL;
  99     }
 100     return ret;
 101 }
 102
 103 void EC_KEY_free(EC_KEY *r)
 104 {
 105     int i;
 106
 107     if (r == NULL)
 108         return;
 109
 110     i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_EC);
 111 #ifdef REF_PRINT
 112     REF_PRINT("EC_KEY", r);
 113 #endif
 114     if (i > 0)
 115         return;
 116 #ifdef REF_CHECK
 117     if (i < 0) {
 118         fprintf(stderr, "EC_KEY_free, bad reference count\n");
 119         abort();
 120     }
 121 #endif
 122
 123     if (r->group != NULL)
 124         EC_GROUP_free(r->group);
 125     if (r->pub_key != NULL)
 126         EC_POINT_free(r->pub_key);
 127     if (r->priv_key != NULL)
 128         BN_clear_free(r->priv_key);
 129
 130     EC_EX_DATA_free_all_data(&r->method_data);
 131
 132     OPENSSL_cleanse((void *)r, sizeof(EC_KEY));
 133
 134     OPENSSL_free(r);
 135 }
 136
 137 EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src)
 138 {
 139     EC_EXTRA_DATA *d;
 140
 141     if (dest == NULL || src == NULL) {
 142         ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER);
 143         return NULL;
 144     }
 145     /* copy the parameters */
 146     if (src->group) {
 147         const EC_METHOD *meth = EC_GROUP_method_of(src->group);
 148         /* clear the old group */
 149         if (dest->group)
 150             EC_GROUP_free(dest->group);
 151         dest->group = EC_GROUP_new(meth);
 152         if (dest->group == NULL)
 153             return NULL;
 154         if (!EC_GROUP_copy(dest->group, src->group))
 155             return NULL;
 156     }
 157     /*  copy the public key */
 158     if (src->pub_key && src->group) {
 159         if (dest->pub_key)
 160             EC_POINT_free(dest->pub_key);
 161         dest->pub_key = EC_POINT_new(src->group);
 162         if (dest->pub_key == NULL)
 163             return NULL;
 164         if (!EC_POINT_copy(dest->pub_key, src->pub_key))
 165             return NULL;
 166     }
 167     /* copy the private key */
 168     if (src->priv_key) {
 169         if (dest->priv_key == NULL) {
 170             dest->priv_key = BN_new();
 171             if (dest->priv_key == NULL)
 172                 return NULL;
 173         }
 174         if (!BN_copy(dest->priv_key, src->priv_key))
 175             return NULL;
 176     }
 177     /* copy method/extra data */
 178     EC_EX_DATA_free_all_data(&dest->method_data);
 179
 180     for (d = src->method_data; d != NULL; d = d->next) {
 181         void *t = d->dup_func(d->data);
 182
 183         if (t == NULL)
 184             return 0;
 185         if (!EC_EX_DATA_set_data
 186             (&dest->method_data, t, d->dup_func, d->free_func,
 187              d->clear_free_func))
 188             return 0;
 189     }
 190
 191     /* copy the rest */
 192     dest->enc_flag = src->enc_flag;
 193     dest->conv_form = src->conv_form;
 194     dest->version = src->version;
 195     dest->flags = src->flags;
 196
 197     return dest;
 198 }
 199
 200 EC_KEY *EC_KEY_dup(const EC_KEY *ec_key)
 201 {
 202     EC_KEY *ret = EC_KEY_new();
 203     if (ret == NULL)
 204         return NULL;
 205     if (EC_KEY_copy(ret, ec_key) == NULL) {
 206         EC_KEY_free(ret);
 207         return NULL;
 208     }
 209     return ret;
 210 }
 211
 212 int EC_KEY_up_ref(EC_KEY *r)
 213 {
 214     int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC);
 215 #ifdef REF_PRINT
 216     REF_PRINT("EC_KEY", r);
 217 #endif
 218 #ifdef REF_CHECK
 219     if (i < 2) {
 220         fprintf(stderr, "EC_KEY_up, bad reference count\n");
 221         abort();
 222     }
 223 #endif
 224     return ((i > 1) ? 1 : 0);
 225 }
 226
 227 int EC_KEY_generate_key(EC_KEY *eckey)
 228 {
 229     int ok = 0;
 230     BN_CTX *ctx = NULL;
 231     BIGNUM *priv_key = NULL, *order = NULL;
 232     EC_POINT *pub_key = NULL;
 233
 234     if (!eckey || !eckey->group) {
 235         ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
 236         return 0;
 237     }
 238
 239     if ((order = BN_new()) == NULL)
 240         goto err;
 241     if ((ctx = BN_CTX_new()) == NULL)
 242         goto err;
 243
 244     if (eckey->priv_key == NULL) {
 245         priv_key = BN_new();
 246         if (priv_key == NULL)
 247             goto err;
 248     } else
 249         priv_key = eckey->priv_key;
 250
 251     if (!EC_GROUP_get_order(eckey->group, order, ctx))
 252         goto err;
 253
 254     do
 255         if (!BN_rand_range(priv_key, order))
 256             goto err;
 257     while (BN_is_zero(priv_key)) ;
 258
 259     if (eckey->pub_key == NULL) {
 260         pub_key = EC_POINT_new(eckey->group);
 261         if (pub_key == NULL)
 262             goto err;
 263     } else
 264         pub_key = eckey->pub_key;
 265
 266     if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
 267         goto err;
 268
 269     eckey->priv_key = priv_key;
 270     eckey->pub_key = pub_key;
 271
 272     ok = 1;
 273
 274  err:
 275     if (order)
 276         BN_free(order);
 277     if (pub_key != NULL && eckey->pub_key == NULL)
 278         EC_POINT_free(pub_key);
 279     if (priv_key != NULL && eckey->priv_key == NULL)
 280         BN_free(priv_key);
 281     if (ctx != NULL)
 282         BN_CTX_free(ctx);
 283     return (ok);
 284 }
 285
 286 int EC_KEY_check_key(const EC_KEY *eckey)
 287 {
 288     int ok = 0;
 289     BN_CTX *ctx = NULL;
 290     const BIGNUM *order = NULL;
 291     EC_POINT *point = NULL;
 292
 293     if (!eckey || !eckey->group || !eckey->pub_key) {
 294         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
 295         return 0;
 296     }
 297
 298     if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) {
 299         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_AT_INFINITY);
 300         goto err;
 301     }
 302
 303     if ((ctx = BN_CTX_new()) == NULL)
 304         goto err;
 305     if ((point = EC_POINT_new(eckey->group)) == NULL)
 306         goto err;
 307
 308     /* testing whether the pub_key is on the elliptic curve */
 309     if (!EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx)) {
 310         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
 311         goto err;
 312     }
 313     /* testing whether pub_key * order is the point at infinity */
 314     order = eckey->group->order;
 315     if (BN_is_zero(order)) {
 316         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
 317         goto err;
 318     }
 319     if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) {
 320         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 321         goto err;
 322     }
 323     if (!EC_POINT_is_at_infinity(eckey->group, point)) {
 324         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 325         goto err;
 326     }
 327     /*
 328      * in case the priv_key is present : check if generator * priv_key ==
 329      * pub_key
 330      */
 331     if (eckey->priv_key) {
 332         if (BN_cmp(eckey->priv_key, order) >= 0) {
 333             ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 334             goto err;
 335         }
 336         if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
 337                           NULL, NULL, ctx)) {
 338             ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 339             goto err;
 340         }
 341         if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, ctx) != 0) {
 342             ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY);
 343             goto err;
 344         }
 345     }
 346     ok = 1;
 347  err:
 348     if (ctx != NULL)
 349         BN_CTX_free(ctx);
 350     if (point != NULL)
 351         EC_POINT_free(point);
 352     return (ok);
 353 }
 354
 355 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
 356                                              BIGNUM *y)
 357 {
 358     BN_CTX *ctx = NULL;
 359     BIGNUM *tx, *ty;
 360     EC_POINT *point = NULL;
 361     int ok = 0, tmp_nid, is_char_two = 0;
 362
 363     if (!key || !key->group || !x || !y) {
 364         ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
 365               ERR_R_PASSED_NULL_PARAMETER);
 366         return 0;
 367     }
 368     ctx = BN_CTX_new();
 369     if (!ctx)
 370         goto err;
 371
 372     point = EC_POINT_new(key->group);
 373
 374     if (!point)
 375         goto err;
 376
 377     tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group));
 378
 379     if (tmp_nid == NID_X9_62_characteristic_two_field)
 380         is_char_two = 1;
 381
 382     tx = BN_CTX_get(ctx);
 383     ty = BN_CTX_get(ctx);
 384 #ifndef OPENSSL_NO_EC2M
 385     if (is_char_two) {
 386         if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point,
 387                                                   x, y, ctx))
 388             goto err;
 389         if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point,
 390                                                   tx, ty, ctx))
 391             goto err;
 392     } else
 393 #endif
 394     {
 395         if (!EC_POINT_set_affine_coordinates_GFp(key->group, point,
 396                                                  x, y, ctx))
 397             goto err;
 398         if (!EC_POINT_get_affine_coordinates_GFp(key->group, point,
 399                                                  tx, ty, ctx))
 400             goto err;
 401     }
 402     /*
 403      * Check if retrieved coordinates match originals and are less than field
 404      * order: if not values are out of range.
 405      */
 406     if (BN_cmp(x, tx) || BN_cmp(y, ty)
 407         || (BN_cmp(x, key->group->field) >= 0)
 408         || (BN_cmp(y, key->group->field) >= 0)) {
 409         ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
 410               EC_R_COORDINATES_OUT_OF_RANGE);
 411         goto err;
 412     }
 413
 414     if (!EC_KEY_set_public_key(key, point))
 415         goto err;
 416
 417     if (EC_KEY_check_key(key) == 0)
 418         goto err;
 419
 420     ok = 1;
 421
 422  err:
 423     if (ctx)
 424         BN_CTX_free(ctx);
 425     if (point)
 426         EC_POINT_free(point);
 427     return ok;
 428
 429 }
 430
 431 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key)
 432 {
 433     return key->group;
 434 }
 435
 436 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group)
 437 {
 438     if (key->group != NULL)
 439         EC_GROUP_free(key->group);
 440     key->group = EC_GROUP_dup(group);
 441     return (key->group == NULL) ? 0 : 1;
 442 }
 443
 444 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key)
 445 {
 446     return key->priv_key;
 447 }
 448
 449 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key)
 450 {
 451     if (key->priv_key)
 452         BN_clear_free(key->priv_key);
 453     key->priv_key = BN_dup(priv_key);
 454     return (key->priv_key == NULL) ? 0 : 1;
 455 }
 456
 457 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key)
 458 {
 459     return key->pub_key;
 460 }
 461
 462 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key)
 463 {
 464     if (key->pub_key != NULL)
 465         EC_POINT_free(key->pub_key);
 466     key->pub_key = EC_POINT_dup(pub_key, key->group);
 467     return (key->pub_key == NULL) ? 0 : 1;
 468 }
 469
 470 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key)
 471 {
 472     return key->enc_flag;
 473 }
 474
 475 void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags)
 476 {
 477     key->enc_flag = flags;
 478 }
 479
 480 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key)
 481 {
 482     return key->conv_form;
 483 }
 484
 485 void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform)
 486 {
 487     key->conv_form = cform;
 488     if (key->group != NULL)
 489         EC_GROUP_set_point_conversion_form(key->group, cform);
 490 }
 491
 492 void *EC_KEY_get_key_method_data(EC_KEY *key,
 493                                  void *(*dup_func) (void *),
 494                                  void (*free_func) (void *),
 495                                  void (*clear_free_func) (void *))
 496 {
 497     void *ret;
 498
 499     CRYPTO_r_lock(CRYPTO_LOCK_EC);
 500     ret =
 501         EC_EX_DATA_get_data(key->method_data, dup_func, free_func,
 502                             clear_free_func);
 503     CRYPTO_r_unlock(CRYPTO_LOCK_EC);
 504
 505     return ret;
 506 }
 507
 508 void *EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
 509                                     void *(*dup_func) (void *),
 510                                     void (*free_func) (void *),
 511                                     void (*clear_free_func) (void *))
 512 {
 513     EC_EXTRA_DATA *ex_data;
 514
 515     CRYPTO_w_lock(CRYPTO_LOCK_EC);
 516     ex_data =
 517         EC_EX_DATA_get_data(key->method_data, dup_func, free_func,
 518                             clear_free_func);
 519     if (ex_data == NULL)
 520         EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func,
 521                             clear_free_func);
 522     CRYPTO_w_unlock(CRYPTO_LOCK_EC);
 523
 524     return ex_data;
 525 }
 526
 527 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag)
 528 {
 529     if (key->group != NULL)
 530         EC_GROUP_set_asn1_flag(key->group, flag);
 531 }
 532
 533 int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx)
 534 {
 535     if (key->group == NULL)
 536         return 0;
 537     return EC_GROUP_precompute_mult(key->group, ctx);
 538 }
 539
 540 int EC_KEY_get_flags(const EC_KEY *key)
 541 {
 542     return key->flags;
 543 }
 544
 545 void EC_KEY_set_flags(EC_KEY *key, int flags)
 546 {
 547     key->flags |= flags;
 548 }
 549
 550 void EC_KEY_clear_flags(EC_KEY *key, int flags)
 551 {
 552     key->flags &= ~flags;
 553 }