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 = OPENSSL_zalloc(sizeof(*ret));
  71
  72     if (ret == NULL) {
  73         ECerr(EC_F_EC_KEY_NEW, ERR_R_MALLOC_FAILURE);
  74         return (NULL);
  75     }
  76
  77     ret->version = 1;
  78     ret->conv_form = POINT_CONVERSION_UNCOMPRESSED;
  79     ret->references = 1;
  80     return (ret);
  81 }
  82
  83 EC_KEY *EC_KEY_new_by_curve_name(int nid)
  84 {
  85     EC_KEY *ret = EC_KEY_new();
  86     if (ret == NULL)
  87         return NULL;
  88     ret->group = EC_GROUP_new_by_curve_name(nid);
  89     if (ret->group == NULL) {
  90         EC_KEY_free(ret);
  91         return NULL;
  92     }
  93     return ret;
  94 }
  95
  96 void EC_KEY_free(EC_KEY *r)
  97 {
  98     int i;
  99
 100     if (r == NULL)
 101         return;
 102
 103     i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_EC);
 104 #ifdef REF_PRINT
 105     REF_PRINT("EC_KEY", r);
 106 #endif
 107     if (i > 0)
 108         return;
 109 #ifdef REF_CHECK
 110     if (i < 0) {
 111         fprintf(stderr, "EC_KEY_free, bad reference count\n");
 112         abort();
 113     }
 114 #endif
 115
 116     EC_GROUP_free(r->group);
 117     EC_POINT_free(r->pub_key);
 118     BN_clear_free(r->priv_key);
 119
 120     EC_EX_DATA_free_all_data(&r->method_data);
 121
 122     OPENSSL_clear_free((void *)r, sizeof(EC_KEY));
 123 }
 124
 125 EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src)
 126 {
 127     EC_EXTRA_DATA *d;
 128
 129     if (dest == NULL || src == NULL) {
 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         const EC_METHOD *meth = EC_GROUP_method_of(src->group);
 136         /* clear the old group */
 137         EC_GROUP_free(dest->group);
 138         dest->group = EC_GROUP_new(meth);
 139         if (dest->group == NULL)
 140             return NULL;
 141         if (!EC_GROUP_copy(dest->group, src->group))
 142             return NULL;
 143     }
 144     /*  copy the public key */
 145     if (src->pub_key && src->group) {
 146         EC_POINT_free(dest->pub_key);
 147         dest->pub_key = EC_POINT_new(src->group);
 148         if (dest->pub_key == NULL)
 149             return NULL;
 150         if (!EC_POINT_copy(dest->pub_key, src->pub_key))
 151             return NULL;
 152     }
 153     /* copy the private key */
 154     if (src->priv_key) {
 155         if (dest->priv_key == NULL) {
 156             dest->priv_key = BN_new();
 157             if (dest->priv_key == NULL)
 158                 return NULL;
 159         }
 160         if (!BN_copy(dest->priv_key, src->priv_key))
 161             return NULL;
 162     }
 163     /* copy method/extra data */
 164     EC_EX_DATA_free_all_data(&dest->method_data);
 165
 166     for (d = src->method_data; d != NULL; d = d->next) {
 167         void *t = d->dup_func(d->data);
 168
 169         if (t == NULL)
 170             return 0;
 171         if (!EC_EX_DATA_set_data
 172             (&dest->method_data, t, d->dup_func, d->free_func,
 173              d->clear_free_func))
 174             return 0;
 175     }
 176
 177     /* copy the rest */
 178     dest->enc_flag = src->enc_flag;
 179     dest->conv_form = src->conv_form;
 180     dest->version = src->version;
 181     dest->flags = src->flags;
 182
 183     return dest;
 184 }
 185
 186 EC_KEY *EC_KEY_dup(const EC_KEY *ec_key)
 187 {
 188     EC_KEY *ret = EC_KEY_new();
 189     if (ret == NULL)
 190         return NULL;
 191     if (EC_KEY_copy(ret, ec_key) == NULL) {
 192         EC_KEY_free(ret);
 193         return NULL;
 194     }
 195     return ret;
 196 }
 197
 198 int EC_KEY_up_ref(EC_KEY *r)
 199 {
 200     int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC);
 201 #ifdef REF_PRINT
 202     REF_PRINT("EC_KEY", r);
 203 #endif
 204 #ifdef REF_CHECK
 205     if (i < 2) {
 206         fprintf(stderr, "EC_KEY_up, bad reference count\n");
 207         abort();
 208     }
 209 #endif
 210     return ((i > 1) ? 1 : 0);
 211 }
 212
 213 int EC_KEY_generate_key(EC_KEY *eckey)
 214 {
 215     int ok = 0;
 216     BN_CTX *ctx = NULL;
 217     BIGNUM *priv_key = NULL, *order = NULL;
 218     EC_POINT *pub_key = NULL;
 219
 220     if (!eckey || !eckey->group) {
 221         ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
 222         return 0;
 223     }
 224
 225     if ((order = BN_new()) == NULL)
 226         goto err;
 227     if ((ctx = BN_CTX_new()) == NULL)
 228         goto err;
 229
 230     if (eckey->priv_key == NULL) {
 231         priv_key = BN_new();
 232         if (priv_key == NULL)
 233             goto err;
 234     } else
 235         priv_key = eckey->priv_key;
 236
 237     if (!EC_GROUP_get_order(eckey->group, order, ctx))
 238         goto err;
 239
 240     do
 241         if (!BN_rand_range(priv_key, order))
 242             goto err;
 243     while (BN_is_zero(priv_key)) ;
 244
 245     if (eckey->pub_key == NULL) {
 246         pub_key = EC_POINT_new(eckey->group);
 247         if (pub_key == NULL)
 248             goto err;
 249     } else
 250         pub_key = eckey->pub_key;
 251
 252     if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
 253         goto err;
 254
 255     eckey->priv_key = priv_key;
 256     eckey->pub_key = pub_key;
 257
 258     ok = 1;
 259
 260  err:
 261     BN_free(order);
 262     if (eckey->pub_key == NULL)
 263         EC_POINT_free(pub_key);
 264     if (eckey->priv_key != priv_key)
 265         BN_free(priv_key);
 266     BN_CTX_free(ctx);
 267     return (ok);
 268 }
 269
 270 int EC_KEY_check_key(const EC_KEY *eckey)
 271 {
 272     int ok = 0;
 273     BN_CTX *ctx = NULL;
 274     const BIGNUM *order = NULL;
 275     EC_POINT *point = NULL;
 276
 277     if (!eckey || !eckey->group || !eckey->pub_key) {
 278         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
 279         return 0;
 280     }
 281
 282     if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) {
 283         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_AT_INFINITY);
 284         goto err;
 285     }
 286
 287     if ((ctx = BN_CTX_new()) == NULL)
 288         goto err;
 289     if ((point = EC_POINT_new(eckey->group)) == NULL)
 290         goto err;
 291
 292     /* testing whether the pub_key is on the elliptic curve */
 293     if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) {
 294         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
 295         goto err;
 296     }
 297     /* testing whether pub_key * order is the point at infinity */
 298     order = eckey->group->order;
 299     if (BN_is_zero(order)) {
 300         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
 301         goto err;
 302     }
 303     if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) {
 304         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 305         goto err;
 306     }
 307     if (!EC_POINT_is_at_infinity(eckey->group, point)) {
 308         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 309         goto err;
 310     }
 311     /*
 312      * in case the priv_key is present : check if generator * priv_key ==
 313      * pub_key
 314      */
 315     if (eckey->priv_key) {
 316         if (BN_cmp(eckey->priv_key, order) >= 0) {
 317             ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 318             goto err;
 319         }
 320         if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
 321                           NULL, NULL, ctx)) {
 322             ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 323             goto err;
 324         }
 325         if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, ctx) != 0) {
 326             ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY);
 327             goto err;
 328         }
 329     }
 330     ok = 1;
 331  err:
 332     BN_CTX_free(ctx);
 333     EC_POINT_free(point);
 334     return (ok);
 335 }
 336
 337 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
 338                                              BIGNUM *y)
 339 {
 340     BN_CTX *ctx = NULL;
 341     BIGNUM *tx, *ty;
 342     EC_POINT *point = NULL;
 343     int ok = 0;
 344 #ifndef OPENSSL_NO_EC2M
 345     int tmp_nid, is_char_two = 0;
 346 #endif
 347
 348     if (!key || !key->group || !x || !y) {
 349         ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
 350               ERR_R_PASSED_NULL_PARAMETER);
 351         return 0;
 352     }
 353     ctx = BN_CTX_new();
 354     if (!ctx)
 355         goto err;
 356
 357     point = EC_POINT_new(key->group);
 358
 359     if (!point)
 360         goto err;
 361
 362     tx = BN_CTX_get(ctx);
 363     ty = BN_CTX_get(ctx);
 364
 365 #ifndef OPENSSL_NO_EC2M
 366     tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group));
 367
 368     if (tmp_nid == NID_X9_62_characteristic_two_field)
 369         is_char_two = 1;
 370
 371     if (is_char_two) {
 372         if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point,
 373                                                   x, y, ctx))
 374             goto err;
 375         if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point,
 376                                                   tx, ty, ctx))
 377             goto err;
 378     } else
 379 #endif
 380     {
 381         if (!EC_POINT_set_affine_coordinates_GFp(key->group, point,
 382                                                  x, y, ctx))
 383             goto err;
 384         if (!EC_POINT_get_affine_coordinates_GFp(key->group, point,
 385                                                  tx, ty, ctx))
 386             goto err;
 387     }
 388     /*
 389      * Check if retrieved coordinates match originals and are less than field
 390      * order: if not values are out of range.
 391      */
 392     if (BN_cmp(x, tx) || BN_cmp(y, ty)
 393         || (BN_cmp(x, key->group->field) >= 0)
 394         || (BN_cmp(y, key->group->field) >= 0)) {
 395         ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
 396               EC_R_COORDINATES_OUT_OF_RANGE);
 397         goto err;
 398     }
 399
 400     if (!EC_KEY_set_public_key(key, point))
 401         goto err;
 402
 403     if (EC_KEY_check_key(key) == 0)
 404         goto err;
 405
 406     ok = 1;
 407
 408  err:
 409     BN_CTX_free(ctx);
 410     EC_POINT_free(point);
 411     return ok;
 412
 413 }
 414
 415 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key)
 416 {
 417     return key->group;
 418 }
 419
 420 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group)
 421 {
 422     EC_GROUP_free(key->group);
 423     key->group = EC_GROUP_dup(group);
 424     return (key->group == NULL) ? 0 : 1;
 425 }
 426
 427 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key)
 428 {
 429     return key->priv_key;
 430 }
 431
 432 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key)
 433 {
 434     BN_clear_free(key->priv_key);
 435     key->priv_key = BN_dup(priv_key);
 436     return (key->priv_key == NULL) ? 0 : 1;
 437 }
 438
 439 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key)
 440 {
 441     return key->pub_key;
 442 }
 443
 444 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key)
 445 {
 446     EC_POINT_free(key->pub_key);
 447     key->pub_key = EC_POINT_dup(pub_key, key->group);
 448     return (key->pub_key == NULL) ? 0 : 1;
 449 }
 450
 451 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key)
 452 {
 453     return key->enc_flag;
 454 }
 455
 456 void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags)
 457 {
 458     key->enc_flag = flags;
 459 }
 460
 461 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key)
 462 {
 463     return key->conv_form;
 464 }
 465
 466 void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform)
 467 {
 468     key->conv_form = cform;
 469     if (key->group != NULL)
 470         EC_GROUP_set_point_conversion_form(key->group, cform);
 471 }
 472
 473 void *EC_KEY_get_key_method_data(EC_KEY *key,
 474                                  void *(*dup_func) (void *),
 475                                  void (*free_func) (void *),
 476                                  void (*clear_free_func) (void *))
 477 {
 478     void *ret;
 479
 480     CRYPTO_r_lock(CRYPTO_LOCK_EC);
 481     ret =
 482         EC_EX_DATA_get_data(key->method_data, dup_func, free_func,
 483                             clear_free_func);
 484     CRYPTO_r_unlock(CRYPTO_LOCK_EC);
 485
 486     return ret;
 487 }
 488
 489 void *EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
 490                                     void *(*dup_func) (void *),
 491                                     void (*free_func) (void *),
 492                                     void (*clear_free_func) (void *))
 493 {
 494     EC_EXTRA_DATA *ex_data;
 495
 496     CRYPTO_w_lock(CRYPTO_LOCK_EC);
 497     ex_data =
 498         EC_EX_DATA_get_data(key->method_data, dup_func, free_func,
 499                             clear_free_func);
 500     if (ex_data == NULL)
 501         EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func,
 502                             clear_free_func);
 503     CRYPTO_w_unlock(CRYPTO_LOCK_EC);
 504
 505     return ex_data;
 506 }
 507
 508 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag)
 509 {
 510     if (key->group != NULL)
 511         EC_GROUP_set_asn1_flag(key->group, flag);
 512 }
 513
 514 int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx)
 515 {
 516     if (key->group == NULL)
 517         return 0;
 518     return EC_GROUP_precompute_mult(key->group, ctx);
 519 }
 520
 521 int EC_KEY_get_flags(const EC_KEY *key)
 522 {
 523     return key->flags;
 524 }
 525
 526 void EC_KEY_set_flags(EC_KEY *key, int flags)
 527 {
 528     key->flags |= flags;
 529 }
 530
 531 void EC_KEY_clear_flags(EC_KEY *key, int flags)
 532 {
 533     key->flags &= ~flags;
 534 }