crypto/ec/ec_lib.c

   1 /* crypto/ec/ec_lib.c */
   2 /*
   3  * Originally written by Bodo Moeller for the OpenSSL project.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 1998-2018 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  * Binary polynomial ECC support in OpenSSL originally developed by
  61  * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
  62  */
  63
  64 #include <string.h>
  65
  66 #include <openssl/err.h>
  67 #include <openssl/opensslv.h>
  68
  69 #include "ec_lcl.h"
  70
  71 const char EC_version[] = "EC" OPENSSL_VERSION_PTEXT;
  72
  73 /* functions for EC_GROUP objects */
  74
  75 EC_GROUP *EC_GROUP_new(const EC_METHOD *meth)
  76 {
  77     EC_GROUP *ret;
  78
  79     if (meth == NULL) {
  80         ECerr(EC_F_EC_GROUP_NEW, EC_R_SLOT_FULL);
  81         return NULL;
  82     }
  83     if (meth->group_init == 0) {
  84         ECerr(EC_F_EC_GROUP_NEW, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  85         return NULL;
  86     }
  87
  88     ret = OPENSSL_malloc(sizeof(*ret));
  89     if (ret == NULL) {
  90         ECerr(EC_F_EC_GROUP_NEW, ERR_R_MALLOC_FAILURE);
  91         return NULL;
  92     }
  93
  94     ret->meth = meth;
  95
  96     ret->extra_data = NULL;
  97     ret->mont_data = NULL;
  98
  99     ret->generator = NULL;
 100     BN_init(&ret->order);
 101     BN_init(&ret->cofactor);
 102
 103     ret->curve_name = 0;
 104     ret->asn1_flag = ~EC_GROUP_ASN1_FLAG_MASK;
 105     ret->asn1_form = POINT_CONVERSION_UNCOMPRESSED;
 106
 107     ret->seed = NULL;
 108     ret->seed_len = 0;
 109
 110     if (!meth->group_init(ret)) {
 111         OPENSSL_free(ret);
 112         return NULL;
 113     }
 114
 115     return ret;
 116 }
 117
 118 void EC_GROUP_free(EC_GROUP *group)
 119 {
 120     if (!group)
 121         return;
 122
 123     if (group->meth->group_finish != 0)
 124         group->meth->group_finish(group);
 125
 126     EC_EX_DATA_free_all_data(&group->extra_data);
 127
 128     if (EC_GROUP_VERSION(group) && group->mont_data)
 129         BN_MONT_CTX_free(group->mont_data);
 130
 131     if (group->generator != NULL)
 132         EC_POINT_free(group->generator);
 133     BN_free(&group->order);
 134     BN_free(&group->cofactor);
 135
 136     if (group->seed)
 137         OPENSSL_free(group->seed);
 138
 139     OPENSSL_free(group);
 140 }
 141
 142 void EC_GROUP_clear_free(EC_GROUP *group)
 143 {
 144     if (!group)
 145         return;
 146
 147     if (group->meth->group_clear_finish != 0)
 148         group->meth->group_clear_finish(group);
 149     else if (group->meth->group_finish != 0)
 150         group->meth->group_finish(group);
 151
 152     EC_EX_DATA_clear_free_all_data(&group->extra_data);
 153
 154     if (EC_GROUP_VERSION(group) && group->mont_data)
 155         BN_MONT_CTX_free(group->mont_data);
 156
 157     if (group->generator != NULL)
 158         EC_POINT_clear_free(group->generator);
 159     BN_clear_free(&group->order);
 160     BN_clear_free(&group->cofactor);
 161
 162     if (group->seed) {
 163         OPENSSL_cleanse(group->seed, group->seed_len);
 164         OPENSSL_free(group->seed);
 165     }
 166
 167     OPENSSL_cleanse(group, sizeof(*group));
 168     OPENSSL_free(group);
 169 }
 170
 171 int EC_GROUP_copy(EC_GROUP *dest, const EC_GROUP *src)
 172 {
 173     EC_EXTRA_DATA *d;
 174
 175     if (dest->meth->group_copy == 0) {
 176         ECerr(EC_F_EC_GROUP_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 177         return 0;
 178     }
 179     if (dest->meth != src->meth) {
 180         ECerr(EC_F_EC_GROUP_COPY, EC_R_INCOMPATIBLE_OBJECTS);
 181         return 0;
 182     }
 183     if (dest == src)
 184         return 1;
 185
 186     EC_EX_DATA_free_all_data(&dest->extra_data);
 187
 188     for (d = src->extra_data; d != NULL; d = d->next) {
 189         void *t = d->dup_func(d->data);
 190
 191         if (t == NULL)
 192             return 0;
 193         if (!EC_EX_DATA_set_data
 194             (&dest->extra_data, t, d->dup_func, d->free_func,
 195              d->clear_free_func))
 196             return 0;
 197     }
 198
 199     if (EC_GROUP_VERSION(src) && src->mont_data != NULL) {
 200         if (dest->mont_data == NULL) {
 201             dest->mont_data = BN_MONT_CTX_new();
 202             if (dest->mont_data == NULL)
 203                 return 0;
 204         }
 205         if (!BN_MONT_CTX_copy(dest->mont_data, src->mont_data))
 206             return 0;
 207     } else {
 208         /* src->generator == NULL */
 209         if (EC_GROUP_VERSION(dest) && dest->mont_data != NULL) {
 210             BN_MONT_CTX_free(dest->mont_data);
 211             dest->mont_data = NULL;
 212         }
 213     }
 214
 215     if (src->generator != NULL) {
 216         if (dest->generator == NULL) {
 217             dest->generator = EC_POINT_new(dest);
 218             if (dest->generator == NULL)
 219                 return 0;
 220         }
 221         if (!EC_POINT_copy(dest->generator, src->generator))
 222             return 0;
 223     } else {
 224         /* src->generator == NULL */
 225         if (dest->generator != NULL) {
 226             EC_POINT_clear_free(dest->generator);
 227             dest->generator = NULL;
 228         }
 229     }
 230
 231     if (!BN_copy(&dest->order, &src->order))
 232         return 0;
 233     if (!BN_copy(&dest->cofactor, &src->cofactor))
 234         return 0;
 235
 236     dest->curve_name = src->curve_name;
 237     dest->asn1_flag = src->asn1_flag;
 238     dest->asn1_form = src->asn1_form;
 239
 240     if (src->seed) {
 241         if (dest->seed)
 242             OPENSSL_free(dest->seed);
 243         dest->seed = OPENSSL_malloc(src->seed_len);
 244         if (dest->seed == NULL)
 245             return 0;
 246         if (!memcpy(dest->seed, src->seed, src->seed_len))
 247             return 0;
 248         dest->seed_len = src->seed_len;
 249     } else {
 250         if (dest->seed)
 251             OPENSSL_free(dest->seed);
 252         dest->seed = NULL;
 253         dest->seed_len = 0;
 254     }
 255
 256     return dest->meth->group_copy(dest, src);
 257 }
 258
 259 EC_GROUP *EC_GROUP_dup(const EC_GROUP *a)
 260 {
 261     EC_GROUP *t = NULL;
 262     int ok = 0;
 263
 264     if (a == NULL)
 265         return NULL;
 266
 267     if ((t = EC_GROUP_new(a->meth)) == NULL)
 268         return (NULL);
 269     if (!EC_GROUP_copy(t, a))
 270         goto err;
 271
 272     ok = 1;
 273
 274  err:
 275     if (!ok) {
 276         if (t)
 277             EC_GROUP_free(t);
 278         return NULL;
 279     } else
 280         return t;
 281 }
 282
 283 const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group)
 284 {
 285     return group->meth;
 286 }
 287
 288 int EC_METHOD_get_field_type(const EC_METHOD *meth)
 289 {
 290     return meth->field_type;
 291 }
 292
 293 int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator,
 294                            const BIGNUM *order, const BIGNUM *cofactor)
 295 {
 296     if (generator == NULL) {
 297         ECerr(EC_F_EC_GROUP_SET_GENERATOR, ERR_R_PASSED_NULL_PARAMETER);
 298         return 0;
 299     }
 300
 301     if (group->generator == NULL) {
 302         group->generator = EC_POINT_new(group);
 303         if (group->generator == NULL)
 304             return 0;
 305     }
 306     if (!EC_POINT_copy(group->generator, generator))
 307         return 0;
 308
 309     if (order != NULL) {
 310         if (!BN_copy(&group->order, order))
 311             return 0;
 312     } else
 313         BN_zero(&group->order);
 314
 315     if (cofactor != NULL) {
 316         if (!BN_copy(&group->cofactor, cofactor))
 317             return 0;
 318     } else
 319         BN_zero(&group->cofactor);
 320
 321     /*
 322      * Some groups have an order with
 323      * factors of two, which makes the Montgomery setup fail.
 324      * |group->mont_data| will be NULL in this case.
 325      */
 326     if (BN_is_odd(&group->order)) {
 327         return ec_precompute_mont_data(group);
 328     }
 329
 330     BN_MONT_CTX_free(group->mont_data);
 331     group->mont_data = NULL;
 332     return 1;
 333 }
 334
 335 const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group)
 336 {
 337     return group->generator;
 338 }
 339
 340 BN_MONT_CTX *EC_GROUP_get_mont_data(const EC_GROUP *group)
 341 {
 342     return EC_GROUP_VERSION(group) ? group->mont_data : NULL;
 343 }
 344
 345 int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, BN_CTX *ctx)
 346 {
 347     if (!BN_copy(order, &group->order))
 348         return 0;
 349
 350     return !BN_is_zero(order);
 351 }
 352
 353 int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor,
 354                           BN_CTX *ctx)
 355 {
 356     if (!BN_copy(cofactor, &group->cofactor))
 357         return 0;
 358
 359     return !BN_is_zero(&group->cofactor);
 360 }
 361
 362 void EC_GROUP_set_curve_name(EC_GROUP *group, int nid)
 363 {
 364     group->curve_name = nid;
 365 }
 366
 367 int EC_GROUP_get_curve_name(const EC_GROUP *group)
 368 {
 369     return group->curve_name;
 370 }
 371
 372 void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag)
 373 {
 374     group->asn1_flag &= ~EC_GROUP_ASN1_FLAG_MASK;
 375     group->asn1_flag |= flag & EC_GROUP_ASN1_FLAG_MASK;
 376 }
 377
 378 int EC_GROUP_get_asn1_flag(const EC_GROUP *group)
 379 {
 380     return group->asn1_flag & EC_GROUP_ASN1_FLAG_MASK;
 381 }
 382
 383 void EC_GROUP_set_point_conversion_form(EC_GROUP *group,
 384                                         point_conversion_form_t form)
 385 {
 386     group->asn1_form = form;
 387 }
 388
 389 point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP
 390                                                            *group)
 391 {
 392     return group->asn1_form;
 393 }
 394
 395 size_t EC_GROUP_set_seed(EC_GROUP *group, const unsigned char *p, size_t len)
 396 {
 397     if (group->seed) {
 398         OPENSSL_free(group->seed);
 399         group->seed = NULL;
 400         group->seed_len = 0;
 401     }
 402
 403     if (!len || !p)
 404         return 1;
 405
 406     if ((group->seed = OPENSSL_malloc(len)) == NULL)
 407         return 0;
 408     memcpy(group->seed, p, len);
 409     group->seed_len = len;
 410
 411     return len;
 412 }
 413
 414 unsigned char *EC_GROUP_get0_seed(const EC_GROUP *group)
 415 {
 416     return group->seed;
 417 }
 418
 419 size_t EC_GROUP_get_seed_len(const EC_GROUP *group)
 420 {
 421     return group->seed_len;
 422 }
 423
 424 int EC_GROUP_set_curve_GFp(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
 425                            const BIGNUM *b, BN_CTX *ctx)
 426 {
 427     if (group->meth->group_set_curve == 0) {
 428         ECerr(EC_F_EC_GROUP_SET_CURVE_GFP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 429         return 0;
 430     }
 431     return group->meth->group_set_curve(group, p, a, b, ctx);
 432 }
 433
 434 int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
 435                            BIGNUM *b, BN_CTX *ctx)
 436 {
 437     if (group->meth->group_get_curve == 0) {
 438         ECerr(EC_F_EC_GROUP_GET_CURVE_GFP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 439         return 0;
 440     }
 441     return group->meth->group_get_curve(group, p, a, b, ctx);
 442 }
 443
 444 #ifndef OPENSSL_NO_EC2M
 445 int EC_GROUP_set_curve_GF2m(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
 446                             const BIGNUM *b, BN_CTX *ctx)
 447 {
 448     if (group->meth->group_set_curve == 0) {
 449         ECerr(EC_F_EC_GROUP_SET_CURVE_GF2M,
 450               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 451         return 0;
 452     }
 453     return group->meth->group_set_curve(group, p, a, b, ctx);
 454 }
 455
 456 int EC_GROUP_get_curve_GF2m(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
 457                             BIGNUM *b, BN_CTX *ctx)
 458 {
 459     if (group->meth->group_get_curve == 0) {
 460         ECerr(EC_F_EC_GROUP_GET_CURVE_GF2M,
 461               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 462         return 0;
 463     }
 464     return group->meth->group_get_curve(group, p, a, b, ctx);
 465 }
 466 #endif
 467
 468 int EC_GROUP_get_degree(const EC_GROUP *group)
 469 {
 470     if (group->meth->group_get_degree == 0) {
 471         ECerr(EC_F_EC_GROUP_GET_DEGREE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 472         return 0;
 473     }
 474     return group->meth->group_get_degree(group);
 475 }
 476
 477 int EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
 478 {
 479     if (group->meth->group_check_discriminant == 0) {
 480         ECerr(EC_F_EC_GROUP_CHECK_DISCRIMINANT,
 481               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 482         return 0;
 483     }
 484     return group->meth->group_check_discriminant(group, ctx);
 485 }
 486
 487 int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ctx)
 488 {
 489     int r = 0;
 490     BIGNUM *a1, *a2, *a3, *b1, *b2, *b3;
 491     BN_CTX *ctx_new = NULL;
 492
 493     /* compare the field types */
 494     if (EC_METHOD_get_field_type(EC_GROUP_method_of(a)) !=
 495         EC_METHOD_get_field_type(EC_GROUP_method_of(b)))
 496         return 1;
 497     /* compare the curve name (if present in both) */
 498     if (EC_GROUP_get_curve_name(a) && EC_GROUP_get_curve_name(b) &&
 499         EC_GROUP_get_curve_name(a) != EC_GROUP_get_curve_name(b))
 500         return 1;
 501
 502     if (!ctx)
 503         ctx_new = ctx = BN_CTX_new();
 504     if (!ctx)
 505         return -1;
 506
 507     BN_CTX_start(ctx);
 508     a1 = BN_CTX_get(ctx);
 509     a2 = BN_CTX_get(ctx);
 510     a3 = BN_CTX_get(ctx);
 511     b1 = BN_CTX_get(ctx);
 512     b2 = BN_CTX_get(ctx);
 513     b3 = BN_CTX_get(ctx);
 514     if (!b3) {
 515         BN_CTX_end(ctx);
 516         if (ctx_new)
 517             BN_CTX_free(ctx);
 518         return -1;
 519     }
 520
 521     /*
 522      * XXX This approach assumes that the external representation of curves
 523      * over the same field type is the same.
 524      */
 525     if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) ||
 526         !b->meth->group_get_curve(b, b1, b2, b3, ctx))
 527         r = 1;
 528
 529     if (r || BN_cmp(a1, b1) || BN_cmp(a2, b2) || BN_cmp(a3, b3))
 530         r = 1;
 531
 532     /* XXX EC_POINT_cmp() assumes that the methods are equal */
 533     if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a),
 534                           EC_GROUP_get0_generator(b), ctx))
 535         r = 1;
 536
 537     if (!r) {
 538         /* compare the order and cofactor */
 539         if (!EC_GROUP_get_order(a, a1, ctx) ||
 540             !EC_GROUP_get_order(b, b1, ctx) ||
 541             !EC_GROUP_get_cofactor(a, a2, ctx) ||
 542             !EC_GROUP_get_cofactor(b, b2, ctx)) {
 543             BN_CTX_end(ctx);
 544             if (ctx_new)
 545                 BN_CTX_free(ctx);
 546             return -1;
 547         }
 548         if (BN_cmp(a1, b1) || BN_cmp(a2, b2))
 549             r = 1;
 550     }
 551
 552     BN_CTX_end(ctx);
 553     if (ctx_new)
 554         BN_CTX_free(ctx);
 555
 556     return r;
 557 }
 558
 559 /* this has 'package' visibility */
 560 int EC_EX_DATA_set_data(EC_EXTRA_DATA **ex_data, void *data,
 561                         void *(*dup_func) (void *),
 562                         void (*free_func) (void *),
 563                         void (*clear_free_func) (void *))
 564 {
 565     EC_EXTRA_DATA *d;
 566
 567     if (ex_data == NULL)
 568         return 0;
 569
 570     for (d = *ex_data; d != NULL; d = d->next) {
 571         if (d->dup_func == dup_func && d->free_func == free_func
 572             && d->clear_free_func == clear_free_func) {
 573             ECerr(EC_F_EC_EX_DATA_SET_DATA, EC_R_SLOT_FULL);
 574             return 0;
 575         }
 576     }
 577
 578     if (data == NULL)
 579         /* no explicit entry needed */
 580         return 1;
 581
 582     d = OPENSSL_malloc(sizeof(*d));
 583     if (d == NULL)
 584         return 0;
 585
 586     d->data = data;
 587     d->dup_func = dup_func;
 588     d->free_func = free_func;
 589     d->clear_free_func = clear_free_func;
 590
 591     d->next = *ex_data;
 592     *ex_data = d;
 593
 594     return 1;
 595 }
 596
 597 /* this has 'package' visibility */
 598 void *EC_EX_DATA_get_data(const EC_EXTRA_DATA *ex_data,
 599                           void *(*dup_func) (void *),
 600                           void (*free_func) (void *),
 601                           void (*clear_free_func) (void *))
 602 {
 603     const EC_EXTRA_DATA *d;
 604
 605     for (d = ex_data; d != NULL; d = d->next) {
 606         if (d->dup_func == dup_func && d->free_func == free_func
 607             && d->clear_free_func == clear_free_func)
 608             return d->data;
 609     }
 610
 611     return NULL;
 612 }
 613
 614 /* this has 'package' visibility */
 615 void EC_EX_DATA_free_data(EC_EXTRA_DATA **ex_data,
 616                           void *(*dup_func) (void *),
 617                           void (*free_func) (void *),
 618                           void (*clear_free_func) (void *))
 619 {
 620     EC_EXTRA_DATA **p;
 621
 622     if (ex_data == NULL)
 623         return;
 624
 625     for (p = ex_data; *p != NULL; p = &((*p)->next)) {
 626         if ((*p)->dup_func == dup_func && (*p)->free_func == free_func
 627             && (*p)->clear_free_func == clear_free_func) {
 628             EC_EXTRA_DATA *next = (*p)->next;
 629
 630             (*p)->free_func((*p)->data);
 631             OPENSSL_free(*p);
 632
 633             *p = next;
 634             return;
 635         }
 636     }
 637 }
 638
 639 /* this has 'package' visibility */
 640 void EC_EX_DATA_clear_free_data(EC_EXTRA_DATA **ex_data,
 641                                 void *(*dup_func) (void *),
 642                                 void (*free_func) (void *),
 643                                 void (*clear_free_func) (void *))
 644 {
 645     EC_EXTRA_DATA **p;
 646
 647     if (ex_data == NULL)
 648         return;
 649
 650     for (p = ex_data; *p != NULL; p = &((*p)->next)) {
 651         if ((*p)->dup_func == dup_func && (*p)->free_func == free_func
 652             && (*p)->clear_free_func == clear_free_func) {
 653             EC_EXTRA_DATA *next = (*p)->next;
 654
 655             (*p)->clear_free_func((*p)->data);
 656             OPENSSL_free(*p);
 657
 658             *p = next;
 659             return;
 660         }
 661     }
 662 }
 663
 664 /* this has 'package' visibility */
 665 void EC_EX_DATA_free_all_data(EC_EXTRA_DATA **ex_data)
 666 {
 667     EC_EXTRA_DATA *d;
 668
 669     if (ex_data == NULL)
 670         return;
 671
 672     d = *ex_data;
 673     while (d) {
 674         EC_EXTRA_DATA *next = d->next;
 675
 676         d->free_func(d->data);
 677         OPENSSL_free(d);
 678
 679         d = next;
 680     }
 681     *ex_data = NULL;
 682 }
 683
 684 /* this has 'package' visibility */
 685 void EC_EX_DATA_clear_free_all_data(EC_EXTRA_DATA **ex_data)
 686 {
 687     EC_EXTRA_DATA *d;
 688
 689     if (ex_data == NULL)
 690         return;
 691
 692     d = *ex_data;
 693     while (d) {
 694         EC_EXTRA_DATA *next = d->next;
 695
 696         d->clear_free_func(d->data);
 697         OPENSSL_free(d);
 698
 699         d = next;
 700     }
 701     *ex_data = NULL;
 702 }
 703
 704 /* functions for EC_POINT objects */
 705
 706 EC_POINT *EC_POINT_new(const EC_GROUP *group)
 707 {
 708     EC_POINT *ret;
 709
 710     if (group == NULL) {
 711         ECerr(EC_F_EC_POINT_NEW, ERR_R_PASSED_NULL_PARAMETER);
 712         return NULL;
 713     }
 714     if (group->meth->point_init == 0) {
 715         ECerr(EC_F_EC_POINT_NEW, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 716         return NULL;
 717     }
 718
 719     ret = OPENSSL_malloc(sizeof(*ret));
 720     if (ret == NULL) {
 721         ECerr(EC_F_EC_POINT_NEW, ERR_R_MALLOC_FAILURE);
 722         return NULL;
 723     }
 724
 725     ret->meth = group->meth;
 726
 727     if (!ret->meth->point_init(ret)) {
 728         OPENSSL_free(ret);
 729         return NULL;
 730     }
 731
 732     return ret;
 733 }
 734
 735 void EC_POINT_free(EC_POINT *point)
 736 {
 737     if (!point)
 738         return;
 739
 740     if (point->meth->point_finish != 0)
 741         point->meth->point_finish(point);
 742     OPENSSL_free(point);
 743 }
 744
 745 void EC_POINT_clear_free(EC_POINT *point)
 746 {
 747     if (!point)
 748         return;
 749
 750     if (point->meth->point_clear_finish != 0)
 751         point->meth->point_clear_finish(point);
 752     else if (point->meth->point_finish != 0)
 753         point->meth->point_finish(point);
 754     OPENSSL_cleanse(point, sizeof(*point));
 755     OPENSSL_free(point);
 756 }
 757
 758 int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src)
 759 {
 760     if (dest->meth->point_copy == 0) {
 761         ECerr(EC_F_EC_POINT_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 762         return 0;
 763     }
 764     if (dest->meth != src->meth) {
 765         ECerr(EC_F_EC_POINT_COPY, EC_R_INCOMPATIBLE_OBJECTS);
 766         return 0;
 767     }
 768     if (dest == src)
 769         return 1;
 770     return dest->meth->point_copy(dest, src);
 771 }
 772
 773 EC_POINT *EC_POINT_dup(const EC_POINT *a, const EC_GROUP *group)
 774 {
 775     EC_POINT *t;
 776     int r;
 777
 778     if (a == NULL)
 779         return NULL;
 780
 781     t = EC_POINT_new(group);
 782     if (t == NULL)
 783         return (NULL);
 784     r = EC_POINT_copy(t, a);
 785     if (!r) {
 786         EC_POINT_free(t);
 787         return NULL;
 788     } else
 789         return t;
 790 }
 791
 792 const EC_METHOD *EC_POINT_method_of(const EC_POINT *point)
 793 {
 794     return point->meth;
 795 }
 796
 797 int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
 798 {
 799     if (group->meth->point_set_to_infinity == 0) {
 800         ECerr(EC_F_EC_POINT_SET_TO_INFINITY,
 801               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 802         return 0;
 803     }
 804     if (group->meth != point->meth) {
 805         ECerr(EC_F_EC_POINT_SET_TO_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
 806         return 0;
 807     }
 808     return group->meth->point_set_to_infinity(group, point);
 809 }
 810
 811 int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
 812                                              EC_POINT *point, const BIGNUM *x,
 813                                              const BIGNUM *y, const BIGNUM *z,
 814                                              BN_CTX *ctx)
 815 {
 816     if (group->meth->point_set_Jprojective_coordinates_GFp == 0) {
 817         ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP,
 818               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 819         return 0;
 820     }
 821     if (group->meth != point->meth) {
 822         ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP,
 823               EC_R_INCOMPATIBLE_OBJECTS);
 824         return 0;
 825     }
 826     return group->meth->point_set_Jprojective_coordinates_GFp(group, point, x,
 827                                                               y, z, ctx);
 828 }
 829
 830 int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
 831                                              const EC_POINT *point, BIGNUM *x,
 832                                              BIGNUM *y, BIGNUM *z,
 833                                              BN_CTX *ctx)
 834 {
 835     if (group->meth->point_get_Jprojective_coordinates_GFp == 0) {
 836         ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP,
 837               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 838         return 0;
 839     }
 840     if (group->meth != point->meth) {
 841         ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP,
 842               EC_R_INCOMPATIBLE_OBJECTS);
 843         return 0;
 844     }
 845     return group->meth->point_get_Jprojective_coordinates_GFp(group, point, x,
 846                                                               y, z, ctx);
 847 }
 848
 849 int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group,
 850                                         EC_POINT *point, const BIGNUM *x,
 851                                         const BIGNUM *y, BN_CTX *ctx)
 852 {
 853     if (group->meth->point_set_affine_coordinates == 0) {
 854         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GFP,
 855               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 856         return 0;
 857     }
 858     if (group->meth != point->meth) {
 859         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GFP,
 860               EC_R_INCOMPATIBLE_OBJECTS);
 861         return 0;
 862     }
 863     return group->meth->point_set_affine_coordinates(group, point, x, y, ctx);
 864 }
 865
 866 #ifndef OPENSSL_NO_EC2M
 867 int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group,
 868                                          EC_POINT *point, const BIGNUM *x,
 869                                          const BIGNUM *y, BN_CTX *ctx)
 870 {
 871     if (group->meth->point_set_affine_coordinates == 0) {
 872         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GF2M,
 873               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 874         return 0;
 875     }
 876     if (group->meth != point->meth) {
 877         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GF2M,
 878               EC_R_INCOMPATIBLE_OBJECTS);
 879         return 0;
 880     }
 881     return group->meth->point_set_affine_coordinates(group, point, x, y, ctx);
 882 }
 883 #endif
 884
 885 int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group,
 886                                         const EC_POINT *point, BIGNUM *x,
 887                                         BIGNUM *y, BN_CTX *ctx)
 888 {
 889     if (group->meth->point_get_affine_coordinates == 0) {
 890         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES_GFP,
 891               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 892         return 0;
 893     }
 894     if (group->meth != point->meth) {
 895         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES_GFP,
 896               EC_R_INCOMPATIBLE_OBJECTS);
 897         return 0;
 898     }
 899     return group->meth->point_get_affine_coordinates(group, point, x, y, ctx);
 900 }
 901
 902 #ifndef OPENSSL_NO_EC2M
 903 int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group,
 904                                          const EC_POINT *point, BIGNUM *x,
 905                                          BIGNUM *y, BN_CTX *ctx)
 906 {
 907     if (group->meth->point_get_affine_coordinates == 0) {
 908         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES_GF2M,
 909               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 910         return 0;
 911     }
 912     if (group->meth != point->meth) {
 913         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES_GF2M,
 914               EC_R_INCOMPATIBLE_OBJECTS);
 915         return 0;
 916     }
 917     return group->meth->point_get_affine_coordinates(group, point, x, y, ctx);
 918 }
 919 #endif
 920
 921 int EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
 922                  const EC_POINT *b, BN_CTX *ctx)
 923 {
 924     if (group->meth->add == 0) {
 925         ECerr(EC_F_EC_POINT_ADD, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 926         return 0;
 927     }
 928     if ((group->meth != r->meth) || (r->meth != a->meth)
 929         || (a->meth != b->meth)) {
 930         ECerr(EC_F_EC_POINT_ADD, EC_R_INCOMPATIBLE_OBJECTS);
 931         return 0;
 932     }
 933     return group->meth->add(group, r, a, b, ctx);
 934 }
 935
 936 int EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
 937                  BN_CTX *ctx)
 938 {
 939     if (group->meth->dbl == 0) {
 940         ECerr(EC_F_EC_POINT_DBL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 941         return 0;
 942     }
 943     if ((group->meth != r->meth) || (r->meth != a->meth)) {
 944         ECerr(EC_F_EC_POINT_DBL, EC_R_INCOMPATIBLE_OBJECTS);
 945         return 0;
 946     }
 947     return group->meth->dbl(group, r, a, ctx);
 948 }
 949
 950 int EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx)
 951 {
 952     if (group->meth->invert == 0) {
 953         ECerr(EC_F_EC_POINT_INVERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 954         return 0;
 955     }
 956     if (group->meth != a->meth) {
 957         ECerr(EC_F_EC_POINT_INVERT, EC_R_INCOMPATIBLE_OBJECTS);
 958         return 0;
 959     }
 960     return group->meth->invert(group, a, ctx);
 961 }
 962
 963 int EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
 964 {
 965     if (group->meth->is_at_infinity == 0) {
 966         ECerr(EC_F_EC_POINT_IS_AT_INFINITY,
 967               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 968         return 0;
 969     }
 970     if (group->meth != point->meth) {
 971         ECerr(EC_F_EC_POINT_IS_AT_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
 972         return 0;
 973     }
 974     return group->meth->is_at_infinity(group, point);
 975 }
 976
 977 /*
 978  * Check whether an EC_POINT is on the curve or not. Note that the return
 979  * value for this function should NOT be treated as a boolean. Return values:
 980  *  1: The point is on the curve
 981  *  0: The point is not on the curve
 982  * -1: An error occurred
 983  */
 984 int EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
 985                          BN_CTX *ctx)
 986 {
 987     if (group->meth->is_on_curve == 0) {
 988         ECerr(EC_F_EC_POINT_IS_ON_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 989         return 0;
 990     }
 991     if (group->meth != point->meth) {
 992         ECerr(EC_F_EC_POINT_IS_ON_CURVE, EC_R_INCOMPATIBLE_OBJECTS);
 993         return 0;
 994     }
 995     return group->meth->is_on_curve(group, point, ctx);
 996 }
 997
 998 int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b,
 999                  BN_CTX *ctx)
1000 {
1001     if (group->meth->point_cmp == 0) {
1002         ECerr(EC_F_EC_POINT_CMP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
1003         return -1;
1004     }
1005     if ((group->meth != a->meth) || (a->meth != b->meth)) {
1006         ECerr(EC_F_EC_POINT_CMP, EC_R_INCOMPATIBLE_OBJECTS);
1007         return -1;
1008     }
1009     return group->meth->point_cmp(group, a, b, ctx);
1010 }
1011
1012 int EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
1013 {
1014     if (group->meth->make_affine == 0) {
1015         ECerr(EC_F_EC_POINT_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
1016         return 0;
1017     }
1018     if (group->meth != point->meth) {
1019         ECerr(EC_F_EC_POINT_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
1020         return 0;
1021     }
1022     return group->meth->make_affine(group, point, ctx);
1023 }
1024
1025 int EC_POINTs_make_affine(const EC_GROUP *group, size_t num,
1026                           EC_POINT *points[], BN_CTX *ctx)
1027 {
1028     size_t i;
1029
1030     if (group->meth->points_make_affine == 0) {
1031         ECerr(EC_F_EC_POINTS_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
1032         return 0;
1033     }
1034     for (i = 0; i < num; i++) {
1035         if (group->meth != points[i]->meth) {
1036             ECerr(EC_F_EC_POINTS_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
1037             return 0;
1038         }
1039     }
1040     return group->meth->points_make_affine(group, num, points, ctx);
1041 }
1042
1043 /*
1044  * Functions for point multiplication. If group->meth->mul is 0, we use the
1045  * wNAF-based implementations in ec_mult.c; otherwise we dispatch through
1046  * methods.
1047  */
1048
1049 int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
1050                   size_t num, const EC_POINT *points[],
1051                   const BIGNUM *scalars[], BN_CTX *ctx)
1052 {
1053     if (group->meth->mul == 0)
1054         /* use default */
1055         return ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
1056
1057     return group->meth->mul(group, r, scalar, num, points, scalars, ctx);
1058 }
1059
1060 int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
1061                  const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx)
1062 {
1063     /* just a convenient interface to EC_POINTs_mul() */
1064
1065     const EC_POINT *points[1];
1066     const BIGNUM *scalars[1];
1067
1068     points[0] = point;
1069     scalars[0] = p_scalar;
1070
1071     return EC_POINTs_mul(group, r, g_scalar,
1072                          (point != NULL
1073                           && p_scalar != NULL), points, scalars, ctx);
1074 }
1075
1076 int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
1077 {
1078     if (group->meth->mul == 0)
1079         /* use default */
1080         return ec_wNAF_precompute_mult(group, ctx);
1081
1082     if (group->meth->precompute_mult != 0)
1083         return group->meth->precompute_mult(group, ctx);
1084     else
1085         return 1;               /* nothing to do, so report success */
1086 }
1087
1088 int EC_GROUP_have_precompute_mult(const EC_GROUP *group)
1089 {
1090     if (group->meth->mul == 0)
1091         /* use default */
1092         return ec_wNAF_have_precompute_mult(group);
1093
1094     if (group->meth->have_precompute_mult != 0)
1095         return group->meth->have_precompute_mult(group);
1096     else
1097         return 0;               /* cannot tell whether precomputation has
1098                                  * been performed */
1099 }
1100
1101 /*
1102  * ec_precompute_mont_data sets |group->mont_data| from |group->order| and
1103  * returns one on success. On error it returns zero.
1104  */
1105 int ec_precompute_mont_data(EC_GROUP *group)
1106 {
1107     BN_CTX *ctx = BN_CTX_new();
1108     int ret = 0;
1109
1110     if (!EC_GROUP_VERSION(group))
1111         goto err;
1112
1113     if (group->mont_data) {
1114         BN_MONT_CTX_free(group->mont_data);
1115         group->mont_data = NULL;
1116     }
1117
1118     if (ctx == NULL)
1119         goto err;
1120
1121     group->mont_data = BN_MONT_CTX_new();
1122     if (!group->mont_data)
1123         goto err;
1124
1125     if (!BN_MONT_CTX_set(group->mont_data, &group->order, ctx)) {
1126         BN_MONT_CTX_free(group->mont_data);
1127         group->mont_data = NULL;
1128         goto err;
1129     }
1130
1131     ret = 1;
1132
1133  err:
1134
1135     if (ctx)
1136         BN_CTX_free(ctx);
1137     return ret;
1138 }