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