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) 1998-2003 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     ret->order = BN_new();
 101     ret->cofactor = NULL;
 102     if (!ret->order)
 103         goto err;
 104     ret->cofactor = BN_new();
 105     if (!ret->cofactor)
 106         goto err;
 107
 108     ret->curve_name = 0;
 109     ret->asn1_flag = OPENSSL_EC_NAMED_CURVE;
 110     ret->asn1_form = POINT_CONVERSION_UNCOMPRESSED;
 111
 112     ret->seed = NULL;
 113     ret->seed_len = 0;
 114
 115     if (!meth->group_init(ret))
 116         goto err;
 117
 118     return ret;
 119  err:
 120     if (ret->order)
 121         BN_free(ret->order);
 122     if (ret->cofactor)
 123         BN_free(ret->cofactor);
 124     OPENSSL_free(ret);
 125     return NULL;
 126 }
 127
 128 void EC_GROUP_free(EC_GROUP *group)
 129 {
 130     if (!group)
 131         return;
 132
 133     if (group->meth->group_finish != 0)
 134         group->meth->group_finish(group);
 135
 136     EC_EX_DATA_free_all_data(&group->extra_data);
 137
 138     if (group->mont_data)
 139         BN_MONT_CTX_free(group->mont_data);
 140
 141     EC_POINT_free(group->generator);
 142     BN_free(group->order);
 143     BN_free(group->cofactor);
 144
 145     if (group->seed)
 146         OPENSSL_free(group->seed);
 147
 148     OPENSSL_free(group);
 149 }
 150
 151 void EC_GROUP_clear_free(EC_GROUP *group)
 152 {
 153     if (!group)
 154         return;
 155
 156     if (group->meth->group_clear_finish != 0)
 157         group->meth->group_clear_finish(group);
 158     else if (group->meth->group_finish != 0)
 159         group->meth->group_finish(group);
 160
 161     EC_EX_DATA_clear_free_all_data(&group->extra_data);
 162
 163     if (group->mont_data)
 164         BN_MONT_CTX_free(group->mont_data);
 165
 166     EC_POINT_clear_free(group->generator);
 167     BN_clear_free(group->order);
 168     BN_clear_free(group->cofactor);
 169
 170     if (group->seed) {
 171         OPENSSL_cleanse(group->seed, group->seed_len);
 172         OPENSSL_free(group->seed);
 173     }
 174
 175     OPENSSL_cleanse(group, sizeof *group);
 176     OPENSSL_free(group);
 177 }
 178
 179 int EC_GROUP_copy(EC_GROUP *dest, const EC_GROUP *src)
 180 {
 181     EC_EXTRA_DATA *d;
 182
 183     if (dest->meth->group_copy == 0) {
 184         ECerr(EC_F_EC_GROUP_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 185         return 0;
 186     }
 187     if (dest->meth != src->meth) {
 188         ECerr(EC_F_EC_GROUP_COPY, EC_R_INCOMPATIBLE_OBJECTS);
 189         return 0;
 190     }
 191     if (dest == src)
 192         return 1;
 193
 194     EC_EX_DATA_free_all_data(&dest->extra_data);
 195
 196     for (d = src->extra_data; d != NULL; d = d->next) {
 197         void *t = d->dup_func(d->data);
 198
 199         if (t == NULL)
 200             return 0;
 201         if (!EC_EX_DATA_set_data
 202             (&dest->extra_data, t, d->dup_func, d->free_func,
 203              d->clear_free_func))
 204             return 0;
 205     }
 206
 207     if (src->mont_data != NULL) {
 208         if (dest->mont_data == NULL) {
 209             dest->mont_data = BN_MONT_CTX_new();
 210             if (dest->mont_data == NULL)
 211                 return 0;
 212         }
 213         if (!BN_MONT_CTX_copy(dest->mont_data, src->mont_data))
 214             return 0;
 215     } else {
 216         /* src->generator == NULL */
 217         if (dest->mont_data != NULL) {
 218             BN_MONT_CTX_free(dest->mont_data);
 219             dest->mont_data = NULL;
 220         }
 221     }
 222
 223     if (src->generator != NULL) {
 224         if (dest->generator == NULL) {
 225             dest->generator = EC_POINT_new(dest);
 226             if (dest->generator == NULL)
 227                 return 0;
 228         }
 229         if (!EC_POINT_copy(dest->generator, src->generator))
 230             return 0;
 231     } else {
 232         /* src->generator == NULL */
 233         EC_POINT_clear_free(dest->generator);
 234         dest->generator = NULL;
 235     }
 236
 237     if (!BN_copy(dest->order, src->order))
 238         return 0;
 239     if (!BN_copy(dest->cofactor, src->cofactor))
 240         return 0;
 241
 242     dest->curve_name = src->curve_name;
 243     dest->asn1_flag = src->asn1_flag;
 244     dest->asn1_form = src->asn1_form;
 245
 246     if (src->seed) {
 247         if (dest->seed)
 248             OPENSSL_free(dest->seed);
 249         dest->seed = OPENSSL_malloc(src->seed_len);
 250         if (dest->seed == NULL)
 251             return 0;
 252         if (!memcpy(dest->seed, src->seed, src->seed_len))
 253             return 0;
 254         dest->seed_len = src->seed_len;
 255     } else {
 256         if (dest->seed)
 257             OPENSSL_free(dest->seed);
 258         dest->seed = NULL;
 259         dest->seed_len = 0;
 260     }
 261
 262     return dest->meth->group_copy(dest, src);
 263 }
 264
 265 EC_GROUP *EC_GROUP_dup(const EC_GROUP *a)
 266 {
 267     EC_GROUP *t = NULL;
 268     int ok = 0;
 269
 270     if (a == NULL)
 271         return NULL;
 272
 273     if ((t = EC_GROUP_new(a->meth)) == NULL)
 274         return (NULL);
 275     if (!EC_GROUP_copy(t, a))
 276         goto err;
 277
 278     ok = 1;
 279
 280  err:
 281     if (!ok) {
 282         EC_GROUP_free(t);
 283         return NULL;
 284     }
 285         return t;
 286 }
 287
 288 const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group)
 289 {
 290     return group->meth;
 291 }
 292
 293 int EC_METHOD_get_field_type(const EC_METHOD *meth)
 294 {
 295     return meth->field_type;
 296 }
 297
 298 int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator,
 299                            const BIGNUM *order, const BIGNUM *cofactor)
 300 {
 301     if (generator == NULL) {
 302         ECerr(EC_F_EC_GROUP_SET_GENERATOR, ERR_R_PASSED_NULL_PARAMETER);
 303         return 0;
 304     }
 305
 306     if (group->generator == NULL) {
 307         group->generator = EC_POINT_new(group);
 308         if (group->generator == NULL)
 309             return 0;
 310     }
 311     if (!EC_POINT_copy(group->generator, generator))
 312         return 0;
 313
 314     if (order != NULL) {
 315         if (!BN_copy(group->order, order))
 316             return 0;
 317     } else
 318         BN_zero(group->order);
 319
 320     if (cofactor != NULL) {
 321         if (!BN_copy(group->cofactor, cofactor))
 322             return 0;
 323     } else
 324         BN_zero(group->cofactor);
 325
 326     /*
 327      * We ignore the return value because some groups have an order with
 328      * factors of two, which makes the Montgomery setup fail.
 329      * |group->mont_data| will be NULL in this case.
 330      */
 331     ec_precompute_mont_data(group);
 332
 333     return 1;
 334 }
 335
 336 const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group)
 337 {
 338     return group->generator;
 339 }
 340
 341 BN_MONT_CTX *EC_GROUP_get_mont_data(const EC_GROUP *group)
 342 {
 343     return group->mont_data;
 344 }
 345
 346 int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, BN_CTX *ctx)
 347 {
 348     if (!BN_copy(order, group->order))
 349         return 0;
 350
 351     return !BN_is_zero(order);
 352 }
 353
 354 int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor,
 355                           BN_CTX *ctx)
 356 {
 357     if (!BN_copy(cofactor, group->cofactor))
 358         return 0;
 359
 360     return !BN_is_zero(group->cofactor);
 361 }
 362
 363 void EC_GROUP_set_curve_name(EC_GROUP *group, int nid)
 364 {
 365     group->curve_name = nid;
 366 }
 367
 368 int EC_GROUP_get_curve_name(const EC_GROUP *group)
 369 {
 370     return group->curve_name;
 371 }
 372
 373 void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag)
 374 {
 375     group->asn1_flag = flag;
 376 }
 377
 378 int EC_GROUP_get_asn1_flag(const EC_GROUP *group)
 379 {
 380     return group->asn1_flag;
 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     }
 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 int EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
 978                          BN_CTX *ctx)
 979 {
 980     if (group->meth->is_on_curve == 0) {
 981         ECerr(EC_F_EC_POINT_IS_ON_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 982         return 0;
 983     }
 984     if (group->meth != point->meth) {
 985         ECerr(EC_F_EC_POINT_IS_ON_CURVE, EC_R_INCOMPATIBLE_OBJECTS);
 986         return 0;
 987     }
 988     return group->meth->is_on_curve(group, point, ctx);
 989 }
 990
 991 int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b,
 992                  BN_CTX *ctx)
 993 {
 994     if (group->meth->point_cmp == 0) {
 995         ECerr(EC_F_EC_POINT_CMP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 996         return -1;
 997     }
 998     if ((group->meth != a->meth) || (a->meth != b->meth)) {
 999         ECerr(EC_F_EC_POINT_CMP, EC_R_INCOMPATIBLE_OBJECTS);
1000         return -1;
1001     }
1002     return group->meth->point_cmp(group, a, b, ctx);
1003 }
1004
1005 int EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
1006 {
1007     if (group->meth->make_affine == 0) {
1008         ECerr(EC_F_EC_POINT_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
1009         return 0;
1010     }
1011     if (group->meth != point->meth) {
1012         ECerr(EC_F_EC_POINT_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
1013         return 0;
1014     }
1015     return group->meth->make_affine(group, point, ctx);
1016 }
1017
1018 int EC_POINTs_make_affine(const EC_GROUP *group, size_t num,
1019                           EC_POINT *points[], BN_CTX *ctx)
1020 {
1021     size_t i;
1022
1023     if (group->meth->points_make_affine == 0) {
1024         ECerr(EC_F_EC_POINTS_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
1025         return 0;
1026     }
1027     for (i = 0; i < num; i++) {
1028         if (group->meth != points[i]->meth) {
1029             ECerr(EC_F_EC_POINTS_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
1030             return 0;
1031         }
1032     }
1033     return group->meth->points_make_affine(group, num, points, ctx);
1034 }
1035
1036 /*
1037  * Functions for point multiplication. If group->meth->mul is 0, we use the
1038  * wNAF-based implementations in ec_mult.c; otherwise we dispatch through
1039  * methods.
1040  */
1041
1042 int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
1043                   size_t num, const EC_POINT *points[],
1044                   const BIGNUM *scalars[], BN_CTX *ctx)
1045 {
1046     if (group->meth->mul == 0)
1047         /* use default */
1048         return ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
1049
1050     return group->meth->mul(group, r, scalar, num, points, scalars, ctx);
1051 }
1052
1053 int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
1054                  const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx)
1055 {
1056     /* just a convenient interface to EC_POINTs_mul() */
1057
1058     const EC_POINT *points[1];
1059     const BIGNUM *scalars[1];
1060
1061     points[0] = point;
1062     scalars[0] = p_scalar;
1063
1064     return EC_POINTs_mul(group, r, g_scalar,
1065                          (point != NULL
1066                           && p_scalar != NULL), points, scalars, ctx);
1067 }
1068
1069 int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
1070 {
1071     if (group->meth->mul == 0)
1072         /* use default */
1073         return ec_wNAF_precompute_mult(group, ctx);
1074
1075     if (group->meth->precompute_mult != 0)
1076         return group->meth->precompute_mult(group, ctx);
1077     else
1078         return 1;               /* nothing to do, so report success */
1079 }
1080
1081 int EC_GROUP_have_precompute_mult(const EC_GROUP *group)
1082 {
1083     if (group->meth->mul == 0)
1084         /* use default */
1085         return ec_wNAF_have_precompute_mult(group);
1086
1087     if (group->meth->have_precompute_mult != 0)
1088         return group->meth->have_precompute_mult(group);
1089     else
1090         return 0;               /* cannot tell whether precomputation has
1091                                  * been performed */
1092 }
1093
1094 /*
1095  * ec_precompute_mont_data sets |group->mont_data| from |group->order| and
1096  * returns one on success. On error it returns zero.
1097  */
1098 int ec_precompute_mont_data(EC_GROUP *group)
1099 {
1100     BN_CTX *ctx = BN_CTX_new();
1101     int ret = 0;
1102
1103     if (group->mont_data) {
1104         BN_MONT_CTX_free(group->mont_data);
1105         group->mont_data = NULL;
1106     }
1107
1108     if (ctx == NULL)
1109         goto err;
1110
1111     group->mont_data = BN_MONT_CTX_new();
1112     if (!group->mont_data)
1113         goto err;
1114
1115     if (!BN_MONT_CTX_set(group->mont_data, group->order, ctx)) {
1116         BN_MONT_CTX_free(group->mont_data);
1117         group->mont_data = NULL;
1118         goto err;
1119     }
1120
1121     ret = 1;
1122
1123  err:
1124
1125     if (ctx)
1126         BN_CTX_free(ctx);
1127     return ret;
1128 }