crypto/openssl/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 #ifdef OPENSSL_FIPS
  68 # include <openssl/fips.h>
  69 #endif
  70
  71 EC_KEY *EC_KEY_new(void)
  72 {
  73     EC_KEY *ret;
  74
  75     ret = (EC_KEY *)OPENSSL_malloc(sizeof(EC_KEY));
  76     if (ret == NULL) {
  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         EC_KEY_free(ret);
 101         return NULL;
 102     }
 103     return ret;
 104 }
 105
 106 void EC_KEY_free(EC_KEY *r)
 107 {
 108     int i;
 109
 110     if (r == NULL)
 111         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)
 118         return;
 119 #ifdef REF_CHECK
 120     if (i < 0) {
 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         ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER);
 146         return NULL;
 147     }
 148     /* copy the parameters */
 149     if (src->group) {
 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         if (dest->pub_key)
 163             EC_POINT_free(dest->pub_key);
 164         dest->pub_key = EC_POINT_new(src->group);
 165         if (dest->pub_key == NULL)
 166             return NULL;
 167         if (!EC_POINT_copy(dest->pub_key, src->pub_key))
 168             return NULL;
 169     }
 170     /* copy the private key */
 171     if (src->priv_key) {
 172         if (dest->priv_key == NULL) {
 173             dest->priv_key = BN_new();
 174             if (dest->priv_key == NULL)
 175                 return NULL;
 176         }
 177         if (!BN_copy(dest->priv_key, src->priv_key))
 178             return NULL;
 179     }
 180     /* copy method/extra data */
 181     EC_EX_DATA_free_all_data(&dest->method_data);
 182
 183     for (d = src->method_data; d != NULL; d = d->next) {
 184         void *t = d->dup_func(d->data);
 185
 186         if (t == NULL)
 187             return 0;
 188         if (!EC_EX_DATA_set_data
 189             (&dest->method_data, t, d->dup_func, d->free_func,
 190              d->clear_free_func))
 191             return 0;
 192     }
 193
 194     /* copy the rest */
 195     dest->enc_flag = src->enc_flag;
 196     dest->conv_form = src->conv_form;
 197     dest->version = src->version;
 198     dest->flags = src->flags;
 199
 200     return dest;
 201 }
 202
 203 EC_KEY *EC_KEY_dup(const EC_KEY *ec_key)
 204 {
 205     EC_KEY *ret = EC_KEY_new();
 206     if (ret == NULL)
 207         return NULL;
 208     if (EC_KEY_copy(ret, ec_key) == NULL) {
 209         EC_KEY_free(ret);
 210         return NULL;
 211     }
 212     return ret;
 213 }
 214
 215 int EC_KEY_up_ref(EC_KEY *r)
 216 {
 217     int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC);
 218 #ifdef REF_PRINT
 219     REF_PRINT("EC_KEY", r);
 220 #endif
 221 #ifdef REF_CHECK
 222     if (i < 2) {
 223         fprintf(stderr, "EC_KEY_up, bad reference count\n");
 224         abort();
 225     }
 226 #endif
 227     return ((i > 1) ? 1 : 0);
 228 }
 229
 230 int EC_KEY_generate_key(EC_KEY *eckey)
 231 {
 232     int ok = 0;
 233     BN_CTX *ctx = NULL;
 234     BIGNUM *priv_key = NULL, *order = NULL;
 235     EC_POINT *pub_key = NULL;
 236
 237 #ifdef OPENSSL_FIPS
 238     if (FIPS_mode())
 239         return FIPS_ec_key_generate_key(eckey);
 240 #endif
 241
 242     if (!eckey || !eckey->group) {
 243         ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
 244         return 0;
 245     }
 246
 247     if ((order = BN_new()) == NULL)
 248         goto err;
 249     if ((ctx = BN_CTX_new()) == NULL)
 250         goto err;
 251
 252     if (eckey->priv_key == NULL) {
 253         priv_key = BN_new();
 254         if (priv_key == NULL)
 255             goto err;
 256     } else
 257         priv_key = eckey->priv_key;
 258
 259     if (!EC_GROUP_get_order(eckey->group, order, ctx))
 260         goto err;
 261
 262     do
 263         if (!BN_rand_range(priv_key, order))
 264             goto err;
 265     while (BN_is_zero(priv_key)) ;
 266
 267     if (eckey->pub_key == NULL) {
 268         pub_key = EC_POINT_new(eckey->group);
 269         if (pub_key == NULL)
 270             goto err;
 271     } else
 272         pub_key = eckey->pub_key;
 273
 274     if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
 275         goto err;
 276
 277     eckey->priv_key = priv_key;
 278     eckey->pub_key = pub_key;
 279
 280     ok = 1;
 281
 282  err:
 283     if (order)
 284         BN_free(order);
 285     if (pub_key != NULL && eckey->pub_key == NULL)
 286         EC_POINT_free(pub_key);
 287     if (priv_key != NULL && eckey->priv_key == NULL)
 288         BN_free(priv_key);
 289     if (ctx != NULL)
 290         BN_CTX_free(ctx);
 291     return (ok);
 292 }
 293
 294 int EC_KEY_check_key(const EC_KEY *eckey)
 295 {
 296     int ok = 0;
 297     BN_CTX *ctx = NULL;
 298     const BIGNUM *order = NULL;
 299     EC_POINT *point = NULL;
 300
 301     if (!eckey || !eckey->group || !eckey->pub_key) {
 302         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
 303         return 0;
 304     }
 305
 306     if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) {
 307         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_AT_INFINITY);
 308         goto err;
 309     }
 310
 311     if ((ctx = BN_CTX_new()) == NULL)
 312         goto err;
 313     if ((point = EC_POINT_new(eckey->group)) == NULL)
 314         goto err;
 315
 316     /* testing whether the pub_key is on the elliptic curve */
 317     if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) {
 318         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
 319         goto err;
 320     }
 321     /* testing whether pub_key * order is the point at infinity */
 322     order = &eckey->group->order;
 323     if (BN_is_zero(order)) {
 324         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
 325         goto err;
 326     }
 327     if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) {
 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         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 333         goto err;
 334     }
 335     /*
 336      * in case the priv_key is present : check if generator * priv_key ==
 337      * pub_key
 338      */
 339     if (eckey->priv_key) {
 340         if (BN_cmp(eckey->priv_key, order) >= 0) {
 341             ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 342             goto err;
 343         }
 344         if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
 345                           NULL, NULL, ctx)) {
 346             ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 347             goto err;
 348         }
 349         if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, ctx) != 0) {
 350             ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY);
 351             goto err;
 352         }
 353     }
 354     ok = 1;
 355  err:
 356     if (ctx != NULL)
 357         BN_CTX_free(ctx);
 358     if (point != NULL)
 359         EC_POINT_free(point);
 360     return (ok);
 361 }
 362
 363 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
 364                                              BIGNUM *y)
 365 {
 366     BN_CTX *ctx = NULL;
 367     BIGNUM *tx, *ty;
 368     EC_POINT *point = NULL;
 369     int ok = 0;
 370 #ifndef OPENSSL_NO_EC2M
 371     int tmp_nid, is_char_two = 0;
 372 #endif
 373
 374     if (!key || !key->group || !x || !y) {
 375         ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
 376               ERR_R_PASSED_NULL_PARAMETER);
 377         return 0;
 378     }
 379     ctx = BN_CTX_new();
 380     if (!ctx)
 381         goto err;
 382
 383     point = EC_POINT_new(key->group);
 384
 385     if (!point)
 386         goto err;
 387
 388     tx = BN_CTX_get(ctx);
 389     ty = BN_CTX_get(ctx);
 390     if (ty == NULL)
 391         goto err;
 392
 393 #ifndef OPENSSL_NO_EC2M
 394     tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group));
 395
 396     if (tmp_nid == NID_X9_62_characteristic_two_field)
 397         is_char_two = 1;
 398
 399     if (is_char_two) {
 400         if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point,
 401                                                   x, y, ctx))
 402             goto err;
 403         if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point,
 404                                                   tx, ty, ctx))
 405             goto err;
 406     } else
 407 #endif
 408     {
 409         if (!EC_POINT_set_affine_coordinates_GFp(key->group, point,
 410                                                  x, y, ctx))
 411             goto err;
 412         if (!EC_POINT_get_affine_coordinates_GFp(key->group, point,
 413                                                  tx, ty, ctx))
 414             goto err;
 415     }
 416     /*
 417      * Check if retrieved coordinates match originals: if not values are out
 418      * of range.
 419      */
 420     if (BN_cmp(x, tx) || BN_cmp(y, ty)) {
 421         ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
 422               EC_R_COORDINATES_OUT_OF_RANGE);
 423         goto err;
 424     }
 425
 426     if (!EC_KEY_set_public_key(key, point))
 427         goto err;
 428
 429     if (EC_KEY_check_key(key) == 0)
 430         goto err;
 431
 432     ok = 1;
 433
 434  err:
 435     if (ctx)
 436         BN_CTX_free(ctx);
 437     if (point)
 438         EC_POINT_free(point);
 439     return ok;
 440
 441 }
 442
 443 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key)
 444 {
 445     return key->group;
 446 }
 447
 448 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group)
 449 {
 450     if (key->group != NULL)
 451         EC_GROUP_free(key->group);
 452     key->group = EC_GROUP_dup(group);
 453     return (key->group == NULL) ? 0 : 1;
 454 }
 455
 456 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key)
 457 {
 458     return key->priv_key;
 459 }
 460
 461 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key)
 462 {
 463     if (key->priv_key)
 464         BN_clear_free(key->priv_key);
 465     key->priv_key = BN_dup(priv_key);
 466     return (key->priv_key == NULL) ? 0 : 1;
 467 }
 468
 469 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key)
 470 {
 471     return key->pub_key;
 472 }
 473
 474 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key)
 475 {
 476     if (key->pub_key != NULL)
 477         EC_POINT_free(key->pub_key);
 478     key->pub_key = EC_POINT_dup(pub_key, key->group);
 479     return (key->pub_key == NULL) ? 0 : 1;
 480 }
 481
 482 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key)
 483 {
 484     return key->enc_flag;
 485 }
 486
 487 void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags)
 488 {
 489     key->enc_flag = flags;
 490 }
 491
 492 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key)
 493 {
 494     return key->conv_form;
 495 }
 496
 497 void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform)
 498 {
 499     key->conv_form = cform;
 500     if (key->group != NULL)
 501         EC_GROUP_set_point_conversion_form(key->group, cform);
 502 }
 503
 504 void *EC_KEY_get_key_method_data(EC_KEY *key,
 505                                  void *(*dup_func) (void *),
 506                                  void (*free_func) (void *),
 507                                  void (*clear_free_func) (void *))
 508 {
 509     void *ret;
 510
 511     CRYPTO_r_lock(CRYPTO_LOCK_EC);
 512     ret =
 513         EC_EX_DATA_get_data(key->method_data, dup_func, free_func,
 514                             clear_free_func);
 515     CRYPTO_r_unlock(CRYPTO_LOCK_EC);
 516
 517     return ret;
 518 }
 519
 520 void *EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
 521                                     void *(*dup_func) (void *),
 522                                     void (*free_func) (void *),
 523                                     void (*clear_free_func) (void *))
 524 {
 525     EC_EXTRA_DATA *ex_data;
 526
 527     CRYPTO_w_lock(CRYPTO_LOCK_EC);
 528     ex_data =
 529         EC_EX_DATA_get_data(key->method_data, dup_func, free_func,
 530                             clear_free_func);
 531     if (ex_data == NULL)
 532         EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func,
 533                             clear_free_func);
 534     CRYPTO_w_unlock(CRYPTO_LOCK_EC);
 535
 536     return ex_data;
 537 }
 538
 539 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag)
 540 {
 541     if (key->group != NULL)
 542         EC_GROUP_set_asn1_flag(key->group, flag);
 543 }
 544
 545 int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx)
 546 {
 547     if (key->group == NULL)
 548         return 0;
 549     return EC_GROUP_precompute_mult(key->group, ctx);
 550 }
 551
 552 int EC_KEY_get_flags(const EC_KEY *key)
 553 {
 554     return key->flags;
 555 }
 556
 557 void EC_KEY_set_flags(EC_KEY *key, int flags)
 558 {
 559     key->flags |= flags;
 560 }
 561
 562 void EC_KEY_clear_flags(EC_KEY *key, int flags)
 563 {
 564     key->flags &= ~flags;
 565 }