crypto/ec/ec_lib.c

   1 /*
   2  * Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
   4  *
   5  * Licensed under the OpenSSL license (the "License").  You may not use
   6  * this file except in compliance with the License.  You can obtain a copy
   7  * in the file LICENSE in the source distribution or at
   8  * https://www.openssl.org/source/license.html
   9  */
  10
  11 #include <string.h>
  12
  13 #include <openssl/err.h>
  14 #include <openssl/opensslv.h>
  15
  16 #include "ec_lcl.h"
  17
  18 /* functions for EC_GROUP objects */
  19
  20 EC_GROUP *EC_GROUP_new(const EC_METHOD *meth)
  21 {
  22     EC_GROUP *ret;
  23
  24     if (meth == NULL) {
  25         ECerr(EC_F_EC_GROUP_NEW, EC_R_SLOT_FULL);
  26         return NULL;
  27     }
  28     if (meth->group_init == 0) {
  29         ECerr(EC_F_EC_GROUP_NEW, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  30         return NULL;
  31     }
  32
  33     ret = OPENSSL_zalloc(sizeof(*ret));
  34     if (ret == NULL) {
  35         ECerr(EC_F_EC_GROUP_NEW, ERR_R_MALLOC_FAILURE);
  36         return NULL;
  37     }
  38
  39     ret->meth = meth;
  40     if ((ret->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) {
  41         ret->order = BN_new();
  42         if (ret->order == NULL)
  43             goto err;
  44         ret->cofactor = BN_new();
  45         if (ret->cofactor == NULL)
  46             goto err;
  47     }
  48     ret->asn1_flag = OPENSSL_EC_NAMED_CURVE;
  49     ret->asn1_form = POINT_CONVERSION_UNCOMPRESSED;
  50     if (!meth->group_init(ret))
  51         goto err;
  52     return ret;
  53
  54  err:
  55     BN_free(ret->order);
  56     BN_free(ret->cofactor);
  57     OPENSSL_free(ret);
  58     return NULL;
  59 }
  60
  61 void EC_pre_comp_free(EC_GROUP *group)
  62 {
  63     switch (group->pre_comp_type) {
  64     case PCT_none:
  65         break;
  66     case PCT_nistz256:
  67 #ifdef ECP_NISTZ256_ASM
  68         EC_nistz256_pre_comp_free(group->pre_comp.nistz256);
  69 #endif
  70         break;
  71 #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
  72     case PCT_nistp224:
  73         EC_nistp224_pre_comp_free(group->pre_comp.nistp224);
  74         break;
  75     case PCT_nistp256:
  76         EC_nistp256_pre_comp_free(group->pre_comp.nistp256);
  77         break;
  78     case PCT_nistp521:
  79         EC_nistp521_pre_comp_free(group->pre_comp.nistp521);
  80         break;
  81 #else
  82     case PCT_nistp224:
  83     case PCT_nistp256:
  84     case PCT_nistp521:
  85         break;
  86 #endif
  87     case PCT_ec:
  88         EC_ec_pre_comp_free(group->pre_comp.ec);
  89         break;
  90     }
  91     group->pre_comp.ec = NULL;
  92 }
  93
  94 void EC_GROUP_free(EC_GROUP *group)
  95 {
  96     if (!group)
  97         return;
  98
  99     if (group->meth->group_finish != 0)
 100         group->meth->group_finish(group);
 101
 102     EC_pre_comp_free(group);
 103     BN_MONT_CTX_free(group->mont_data);
 104     EC_POINT_free(group->generator);
 105     BN_free(group->order);
 106     BN_free(group->cofactor);
 107     OPENSSL_free(group->seed);
 108     OPENSSL_free(group);
 109 }
 110
 111 void EC_GROUP_clear_free(EC_GROUP *group)
 112 {
 113     if (!group)
 114         return;
 115
 116     if (group->meth->group_clear_finish != 0)
 117         group->meth->group_clear_finish(group);
 118     else if (group->meth->group_finish != 0)
 119         group->meth->group_finish(group);
 120
 121     EC_pre_comp_free(group);
 122     BN_MONT_CTX_free(group->mont_data);
 123     EC_POINT_clear_free(group->generator);
 124     BN_clear_free(group->order);
 125     BN_clear_free(group->cofactor);
 126     OPENSSL_clear_free(group->seed, group->seed_len);
 127     OPENSSL_clear_free(group, sizeof(*group));
 128 }
 129
 130 int EC_GROUP_copy(EC_GROUP *dest, const EC_GROUP *src)
 131 {
 132     if (dest->meth->group_copy == 0) {
 133         ECerr(EC_F_EC_GROUP_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 134         return 0;
 135     }
 136     if (dest->meth != src->meth) {
 137         ECerr(EC_F_EC_GROUP_COPY, EC_R_INCOMPATIBLE_OBJECTS);
 138         return 0;
 139     }
 140     if (dest == src)
 141         return 1;
 142
 143     dest->curve_name = src->curve_name;
 144
 145     /* Copy precomputed */
 146     dest->pre_comp_type = src->pre_comp_type;
 147     switch (src->pre_comp_type) {
 148     case PCT_none:
 149         dest->pre_comp.ec = NULL;
 150         break;
 151     case PCT_nistz256:
 152 #ifdef ECP_NISTZ256_ASM
 153         dest->pre_comp.nistz256 = EC_nistz256_pre_comp_dup(src->pre_comp.nistz256);
 154 #endif
 155         break;
 156 #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
 157     case PCT_nistp224:
 158         dest->pre_comp.nistp224 = EC_nistp224_pre_comp_dup(src->pre_comp.nistp224);
 159         break;
 160     case PCT_nistp256:
 161         dest->pre_comp.nistp256 = EC_nistp256_pre_comp_dup(src->pre_comp.nistp256);
 162         break;
 163     case PCT_nistp521:
 164         dest->pre_comp.nistp521 = EC_nistp521_pre_comp_dup(src->pre_comp.nistp521);
 165         break;
 166 #else
 167     case PCT_nistp224:
 168     case PCT_nistp256:
 169     case PCT_nistp521:
 170         break;
 171 #endif
 172     case PCT_ec:
 173         dest->pre_comp.ec = EC_ec_pre_comp_dup(src->pre_comp.ec);
 174         break;
 175     }
 176
 177     if (src->mont_data != NULL) {
 178         if (dest->mont_data == NULL) {
 179             dest->mont_data = BN_MONT_CTX_new();
 180             if (dest->mont_data == NULL)
 181                 return 0;
 182         }
 183         if (!BN_MONT_CTX_copy(dest->mont_data, src->mont_data))
 184             return 0;
 185     } else {
 186         /* src->generator == NULL */
 187         BN_MONT_CTX_free(dest->mont_data);
 188         dest->mont_data = NULL;
 189     }
 190
 191     if (src->generator != NULL) {
 192         if (dest->generator == NULL) {
 193             dest->generator = EC_POINT_new(dest);
 194             if (dest->generator == NULL)
 195                 return 0;
 196         }
 197         if (!EC_POINT_copy(dest->generator, src->generator))
 198             return 0;
 199     } else {
 200         /* src->generator == NULL */
 201         EC_POINT_clear_free(dest->generator);
 202         dest->generator = NULL;
 203     }
 204
 205     if ((src->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) {
 206         if (!BN_copy(dest->order, src->order))
 207             return 0;
 208         if (!BN_copy(dest->cofactor, src->cofactor))
 209             return 0;
 210     }
 211
 212     dest->asn1_flag = src->asn1_flag;
 213     dest->asn1_form = src->asn1_form;
 214
 215     if (src->seed) {
 216         OPENSSL_free(dest->seed);
 217         if ((dest->seed = OPENSSL_malloc(src->seed_len)) == NULL) {
 218             ECerr(EC_F_EC_GROUP_COPY, ERR_R_MALLOC_FAILURE);
 219             return 0;
 220         }
 221         if (!memcpy(dest->seed, src->seed, src->seed_len))
 222             return 0;
 223         dest->seed_len = src->seed_len;
 224     } else {
 225         OPENSSL_free(dest->seed);
 226         dest->seed = NULL;
 227         dest->seed_len = 0;
 228     }
 229
 230     return dest->meth->group_copy(dest, src);
 231 }
 232
 233 EC_GROUP *EC_GROUP_dup(const EC_GROUP *a)
 234 {
 235     EC_GROUP *t = NULL;
 236     int ok = 0;
 237
 238     if (a == NULL)
 239         return NULL;
 240
 241     if ((t = EC_GROUP_new(a->meth)) == NULL)
 242         return NULL;
 243     if (!EC_GROUP_copy(t, a))
 244         goto err;
 245
 246     ok = 1;
 247
 248  err:
 249     if (!ok) {
 250         EC_GROUP_free(t);
 251         return NULL;
 252     }
 253         return t;
 254 }
 255
 256 const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group)
 257 {
 258     return group->meth;
 259 }
 260
 261 int EC_METHOD_get_field_type(const EC_METHOD *meth)
 262 {
 263     return meth->field_type;
 264 }
 265
 266 static int ec_precompute_mont_data(EC_GROUP *);
 267
 268 int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator,
 269                            const BIGNUM *order, const BIGNUM *cofactor)
 270 {
 271     if (generator == NULL) {
 272         ECerr(EC_F_EC_GROUP_SET_GENERATOR, ERR_R_PASSED_NULL_PARAMETER);
 273         return 0;
 274     }
 275
 276     if (group->generator == NULL) {
 277         group->generator = EC_POINT_new(group);
 278         if (group->generator == NULL)
 279             return 0;
 280     }
 281     if (!EC_POINT_copy(group->generator, generator))
 282         return 0;
 283
 284     if (order != NULL) {
 285         if (!BN_copy(group->order, order))
 286             return 0;
 287     } else
 288         BN_zero(group->order);
 289
 290     if (cofactor != NULL) {
 291         if (!BN_copy(group->cofactor, cofactor))
 292             return 0;
 293     } else
 294         BN_zero(group->cofactor);
 295
 296     /*
 297      * Some groups have an order with
 298      * factors of two, which makes the Montgomery setup fail.
 299      * |group->mont_data| will be NULL in this case.
 300      */
 301     if (BN_is_odd(group->order)) {
 302         return ec_precompute_mont_data(group);
 303     }
 304
 305     BN_MONT_CTX_free(group->mont_data);
 306     group->mont_data = NULL;
 307     return 1;
 308 }
 309
 310 const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group)
 311 {
 312     return group->generator;
 313 }
 314
 315 BN_MONT_CTX *EC_GROUP_get_mont_data(const EC_GROUP *group)
 316 {
 317     return group->mont_data;
 318 }
 319
 320 int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, BN_CTX *ctx)
 321 {
 322     if (group->order == NULL)
 323         return 0;
 324     if (!BN_copy(order, group->order))
 325         return 0;
 326
 327     return !BN_is_zero(order);
 328 }
 329
 330 const BIGNUM *EC_GROUP_get0_order(const EC_GROUP *group)
 331 {
 332     return group->order;
 333 }
 334
 335 int EC_GROUP_order_bits(const EC_GROUP *group)
 336 {
 337     return group->meth->group_order_bits(group);
 338 }
 339
 340 int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor,
 341                           BN_CTX *ctx)
 342 {
 343
 344     if (group->cofactor == NULL)
 345         return 0;
 346     if (!BN_copy(cofactor, group->cofactor))
 347         return 0;
 348
 349     return !BN_is_zero(group->cofactor);
 350 }
 351
 352 const BIGNUM *EC_GROUP_get0_cofactor(const EC_GROUP *group)
 353 {
 354     return group->cofactor;
 355 }
 356
 357 void EC_GROUP_set_curve_name(EC_GROUP *group, int nid)
 358 {
 359     group->curve_name = nid;
 360 }
 361
 362 int EC_GROUP_get_curve_name(const EC_GROUP *group)
 363 {
 364     return group->curve_name;
 365 }
 366
 367 void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag)
 368 {
 369     group->asn1_flag = flag;
 370 }
 371
 372 int EC_GROUP_get_asn1_flag(const EC_GROUP *group)
 373 {
 374     return group->asn1_flag;
 375 }
 376
 377 void EC_GROUP_set_point_conversion_form(EC_GROUP *group,
 378                                         point_conversion_form_t form)
 379 {
 380     group->asn1_form = form;
 381 }
 382
 383 point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP
 384                                                            *group)
 385 {
 386     return group->asn1_form;
 387 }
 388
 389 size_t EC_GROUP_set_seed(EC_GROUP *group, const unsigned char *p, size_t len)
 390 {
 391     OPENSSL_free(group->seed);
 392     group->seed = NULL;
 393     group->seed_len = 0;
 394
 395     if (!len || !p)
 396         return 1;
 397
 398     if ((group->seed = OPENSSL_malloc(len)) == NULL) {
 399         ECerr(EC_F_EC_GROUP_SET_SEED, ERR_R_MALLOC_FAILURE);
 400         return 0;
 401     }
 402     memcpy(group->seed, p, len);
 403     group->seed_len = len;
 404
 405     return len;
 406 }
 407
 408 unsigned char *EC_GROUP_get0_seed(const EC_GROUP *group)
 409 {
 410     return group->seed;
 411 }
 412
 413 size_t EC_GROUP_get_seed_len(const EC_GROUP *group)
 414 {
 415     return group->seed_len;
 416 }
 417
 418 int EC_GROUP_set_curve(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
 419                        const BIGNUM *b, BN_CTX *ctx)
 420 {
 421     if (group->meth->group_set_curve == 0) {
 422         ECerr(EC_F_EC_GROUP_SET_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 423         return 0;
 424     }
 425     return group->meth->group_set_curve(group, p, a, b, ctx);
 426 }
 427
 428 int EC_GROUP_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b,
 429                        BN_CTX *ctx)
 430 {
 431     if (group->meth->group_get_curve == NULL) {
 432         ECerr(EC_F_EC_GROUP_GET_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 433         return 0;
 434     }
 435     return group->meth->group_get_curve(group, p, a, b, ctx);
 436 }
 437
 438 #if OPENSSL_API_COMPAT < 0x10200000L
 439 int EC_GROUP_set_curve_GFp(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
 440                            const BIGNUM *b, BN_CTX *ctx)
 441 {
 442     return EC_GROUP_set_curve(group, p, a, b, ctx);
 443 }
 444
 445 int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
 446                            BIGNUM *b, BN_CTX *ctx)
 447 {
 448     return EC_GROUP_get_curve(group, p, a, b, ctx);
 449 }
 450
 451 # ifndef OPENSSL_NO_EC2M
 452 int EC_GROUP_set_curve_GF2m(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
 453                             const BIGNUM *b, BN_CTX *ctx)
 454 {
 455     return EC_GROUP_set_curve(group, p, a, b, ctx);
 456 }
 457
 458 int EC_GROUP_get_curve_GF2m(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
 459                             BIGNUM *b, BN_CTX *ctx)
 460 {
 461     return EC_GROUP_get_curve(group, p, a, b, ctx);
 462 }
 463 # endif
 464 #endif
 465
 466 int EC_GROUP_get_degree(const EC_GROUP *group)
 467 {
 468     if (group->meth->group_get_degree == 0) {
 469         ECerr(EC_F_EC_GROUP_GET_DEGREE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 470         return 0;
 471     }
 472     return group->meth->group_get_degree(group);
 473 }
 474
 475 int EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
 476 {
 477     if (group->meth->group_check_discriminant == 0) {
 478         ECerr(EC_F_EC_GROUP_CHECK_DISCRIMINANT,
 479               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 480         return 0;
 481     }
 482     return group->meth->group_check_discriminant(group, ctx);
 483 }
 484
 485 int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ctx)
 486 {
 487     int r = 0;
 488     BIGNUM *a1, *a2, *a3, *b1, *b2, *b3;
 489     BN_CTX *ctx_new = NULL;
 490
 491     /* compare the field types */
 492     if (EC_METHOD_get_field_type(EC_GROUP_method_of(a)) !=
 493         EC_METHOD_get_field_type(EC_GROUP_method_of(b)))
 494         return 1;
 495     /* compare the curve name (if present in both) */
 496     if (EC_GROUP_get_curve_name(a) && EC_GROUP_get_curve_name(b) &&
 497         EC_GROUP_get_curve_name(a) != EC_GROUP_get_curve_name(b))
 498         return 1;
 499     if (a->meth->flags & EC_FLAGS_CUSTOM_CURVE)
 500         return 0;
 501
 502     if (ctx == NULL)
 503         ctx_new = ctx = BN_CTX_new();
 504     if (ctx == NULL)
 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 == NULL) {
 515         BN_CTX_end(ctx);
 516         BN_CTX_free(ctx_new);
 517         return -1;
 518     }
 519
 520     /*
 521      * XXX This approach assumes that the external representation of curves
 522      * over the same field type is the same.
 523      */
 524     if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) ||
 525         !b->meth->group_get_curve(b, b1, b2, b3, ctx))
 526         r = 1;
 527
 528     if (r || BN_cmp(a1, b1) || BN_cmp(a2, b2) || BN_cmp(a3, b3))
 529         r = 1;
 530
 531     /* XXX EC_POINT_cmp() assumes that the methods are equal */
 532     if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a),
 533                           EC_GROUP_get0_generator(b), ctx))
 534         r = 1;
 535
 536     if (!r) {
 537         const BIGNUM *ao, *bo, *ac, *bc;
 538         /* compare the order and cofactor */
 539         ao = EC_GROUP_get0_order(a);
 540         bo = EC_GROUP_get0_order(b);
 541         ac = EC_GROUP_get0_cofactor(a);
 542         bc = EC_GROUP_get0_cofactor(b);
 543         if (ao == NULL || bo == NULL) {
 544             BN_CTX_end(ctx);
 545             BN_CTX_free(ctx_new);
 546             return -1;
 547         }
 548         if (BN_cmp(ao, bo) || BN_cmp(ac, bc))
 549             r = 1;
 550     }
 551
 552     BN_CTX_end(ctx);
 553     BN_CTX_free(ctx_new);
 554
 555     return r;
 556 }
 557
 558 /* functions for EC_POINT objects */
 559
 560 EC_POINT *EC_POINT_new(const EC_GROUP *group)
 561 {
 562     EC_POINT *ret;
 563
 564     if (group == NULL) {
 565         ECerr(EC_F_EC_POINT_NEW, ERR_R_PASSED_NULL_PARAMETER);
 566         return NULL;
 567     }
 568     if (group->meth->point_init == NULL) {
 569         ECerr(EC_F_EC_POINT_NEW, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 570         return NULL;
 571     }
 572
 573     ret = OPENSSL_zalloc(sizeof(*ret));
 574     if (ret == NULL) {
 575         ECerr(EC_F_EC_POINT_NEW, ERR_R_MALLOC_FAILURE);
 576         return NULL;
 577     }
 578
 579     ret->meth = group->meth;
 580     ret->curve_name = group->curve_name;
 581
 582     if (!ret->meth->point_init(ret)) {
 583         OPENSSL_free(ret);
 584         return NULL;
 585     }
 586
 587     return ret;
 588 }
 589
 590 void EC_POINT_free(EC_POINT *point)
 591 {
 592     if (!point)
 593         return;
 594
 595     if (point->meth->point_finish != 0)
 596         point->meth->point_finish(point);
 597     OPENSSL_free(point);
 598 }
 599
 600 void EC_POINT_clear_free(EC_POINT *point)
 601 {
 602     if (!point)
 603         return;
 604
 605     if (point->meth->point_clear_finish != 0)
 606         point->meth->point_clear_finish(point);
 607     else if (point->meth->point_finish != 0)
 608         point->meth->point_finish(point);
 609     OPENSSL_clear_free(point, sizeof(*point));
 610 }
 611
 612 int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src)
 613 {
 614     if (dest->meth->point_copy == 0) {
 615         ECerr(EC_F_EC_POINT_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 616         return 0;
 617     }
 618     if (dest->meth != src->meth
 619             || (dest->curve_name != src->curve_name
 620                 && dest->curve_name != 0
 621                 && src->curve_name != 0)) {
 622         ECerr(EC_F_EC_POINT_COPY, EC_R_INCOMPATIBLE_OBJECTS);
 623         return 0;
 624     }
 625     if (dest == src)
 626         return 1;
 627     return dest->meth->point_copy(dest, src);
 628 }
 629
 630 EC_POINT *EC_POINT_dup(const EC_POINT *a, const EC_GROUP *group)
 631 {
 632     EC_POINT *t;
 633     int r;
 634
 635     if (a == NULL)
 636         return NULL;
 637
 638     t = EC_POINT_new(group);
 639     if (t == NULL)
 640         return NULL;
 641     r = EC_POINT_copy(t, a);
 642     if (!r) {
 643         EC_POINT_free(t);
 644         return NULL;
 645     }
 646     return t;
 647 }
 648
 649 const EC_METHOD *EC_POINT_method_of(const EC_POINT *point)
 650 {
 651     return point->meth;
 652 }
 653
 654 int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
 655 {
 656     if (group->meth->point_set_to_infinity == 0) {
 657         ECerr(EC_F_EC_POINT_SET_TO_INFINITY,
 658               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 659         return 0;
 660     }
 661     if (group->meth != point->meth) {
 662         ECerr(EC_F_EC_POINT_SET_TO_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
 663         return 0;
 664     }
 665     return group->meth->point_set_to_infinity(group, point);
 666 }
 667
 668 int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
 669                                              EC_POINT *point, const BIGNUM *x,
 670                                              const BIGNUM *y, const BIGNUM *z,
 671                                              BN_CTX *ctx)
 672 {
 673     if (group->meth->point_set_Jprojective_coordinates_GFp == 0) {
 674         ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP,
 675               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 676         return 0;
 677     }
 678     if (!ec_point_is_compat(point, group)) {
 679         ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP,
 680               EC_R_INCOMPATIBLE_OBJECTS);
 681         return 0;
 682     }
 683     return group->meth->point_set_Jprojective_coordinates_GFp(group, point, x,
 684                                                               y, z, ctx);
 685 }
 686
 687 int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
 688                                              const EC_POINT *point, BIGNUM *x,
 689                                              BIGNUM *y, BIGNUM *z,
 690                                              BN_CTX *ctx)
 691 {
 692     if (group->meth->point_get_Jprojective_coordinates_GFp == 0) {
 693         ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP,
 694               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 695         return 0;
 696     }
 697     if (!ec_point_is_compat(point, group)) {
 698         ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP,
 699               EC_R_INCOMPATIBLE_OBJECTS);
 700         return 0;
 701     }
 702     return group->meth->point_get_Jprojective_coordinates_GFp(group, point, x,
 703                                                               y, z, ctx);
 704 }
 705
 706 int EC_POINT_set_affine_coordinates(const EC_GROUP *group, EC_POINT *point,
 707                                     const BIGNUM *x, const BIGNUM *y,
 708                                     BN_CTX *ctx)
 709 {
 710     if (group->meth->point_set_affine_coordinates == NULL) {
 711         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES,
 712               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 713         return 0;
 714     }
 715     if (!ec_point_is_compat(point, group)) {
 716         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES, EC_R_INCOMPATIBLE_OBJECTS);
 717         return 0;
 718     }
 719     if (!group->meth->point_set_affine_coordinates(group, point, x, y, ctx))
 720         return 0;
 721
 722     if (EC_POINT_is_on_curve(group, point, ctx) <= 0) {
 723         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES, EC_R_POINT_IS_NOT_ON_CURVE);
 724         return 0;
 725     }
 726     return 1;
 727 }
 728
 729 #if OPENSSL_API_COMPAT < 0x10200000L
 730 int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group,
 731                                         EC_POINT *point, const BIGNUM *x,
 732                                         const BIGNUM *y, BN_CTX *ctx)
 733 {
 734     return EC_POINT_set_affine_coordinates(group, point, x, y, ctx);
 735 }
 736
 737 # ifndef OPENSSL_NO_EC2M
 738 int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group,
 739                                          EC_POINT *point, const BIGNUM *x,
 740                                          const BIGNUM *y, BN_CTX *ctx)
 741 {
 742     return EC_POINT_set_affine_coordinates(group, point, x, y, ctx);
 743 }
 744 # endif
 745 #endif
 746
 747 int EC_POINT_get_affine_coordinates(const EC_GROUP *group,
 748                                     const EC_POINT *point, BIGNUM *x, BIGNUM *y,
 749                                     BN_CTX *ctx)
 750 {
 751     if (group->meth->point_get_affine_coordinates == NULL) {
 752         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES,
 753               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 754         return 0;
 755     }
 756     if (!ec_point_is_compat(point, group)) {
 757         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES, EC_R_INCOMPATIBLE_OBJECTS);
 758         return 0;
 759     }
 760     if (EC_POINT_is_at_infinity(group, point)) {
 761         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES, EC_R_POINT_AT_INFINITY);
 762         return 0;
 763     }
 764     return group->meth->point_get_affine_coordinates(group, point, x, y, ctx);
 765 }
 766
 767 #if OPENSSL_API_COMPAT < 0x10200000L
 768 int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group,
 769                                         const EC_POINT *point, BIGNUM *x,
 770                                         BIGNUM *y, BN_CTX *ctx)
 771 {
 772     return EC_POINT_get_affine_coordinates(group, point, x, y, ctx);
 773 }
 774
 775 # ifndef OPENSSL_NO_EC2M
 776 int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group,
 777                                          const EC_POINT *point, BIGNUM *x,
 778                                          BIGNUM *y, BN_CTX *ctx)
 779 {
 780     return EC_POINT_get_affine_coordinates(group, point, x, y, ctx);
 781 }
 782 # endif
 783 #endif
 784
 785 int EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
 786                  const EC_POINT *b, BN_CTX *ctx)
 787 {
 788     if (group->meth->add == 0) {
 789         ECerr(EC_F_EC_POINT_ADD, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 790         return 0;
 791     }
 792     if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group)
 793         || !ec_point_is_compat(b, group)) {
 794         ECerr(EC_F_EC_POINT_ADD, EC_R_INCOMPATIBLE_OBJECTS);
 795         return 0;
 796     }
 797     return group->meth->add(group, r, a, b, ctx);
 798 }
 799
 800 int EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
 801                  BN_CTX *ctx)
 802 {
 803     if (group->meth->dbl == 0) {
 804         ECerr(EC_F_EC_POINT_DBL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 805         return 0;
 806     }
 807     if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group)) {
 808         ECerr(EC_F_EC_POINT_DBL, EC_R_INCOMPATIBLE_OBJECTS);
 809         return 0;
 810     }
 811     return group->meth->dbl(group, r, a, ctx);
 812 }
 813
 814 int EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx)
 815 {
 816     if (group->meth->invert == 0) {
 817         ECerr(EC_F_EC_POINT_INVERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 818         return 0;
 819     }
 820     if (!ec_point_is_compat(a, group)) {
 821         ECerr(EC_F_EC_POINT_INVERT, EC_R_INCOMPATIBLE_OBJECTS);
 822         return 0;
 823     }
 824     return group->meth->invert(group, a, ctx);
 825 }
 826
 827 int EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
 828 {
 829     if (group->meth->is_at_infinity == 0) {
 830         ECerr(EC_F_EC_POINT_IS_AT_INFINITY,
 831               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 832         return 0;
 833     }
 834     if (!ec_point_is_compat(point, group)) {
 835         ECerr(EC_F_EC_POINT_IS_AT_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
 836         return 0;
 837     }
 838     return group->meth->is_at_infinity(group, point);
 839 }
 840
 841 /*
 842  * Check whether an EC_POINT is on the curve or not. Note that the return
 843  * value for this function should NOT be treated as a boolean. Return values:
 844  *  1: The point is on the curve
 845  *  0: The point is not on the curve
 846  * -1: An error occurred
 847  */
 848 int EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
 849                          BN_CTX *ctx)
 850 {
 851     if (group->meth->is_on_curve == 0) {
 852         ECerr(EC_F_EC_POINT_IS_ON_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 853         return 0;
 854     }
 855     if (!ec_point_is_compat(point, group)) {
 856         ECerr(EC_F_EC_POINT_IS_ON_CURVE, EC_R_INCOMPATIBLE_OBJECTS);
 857         return 0;
 858     }
 859     return group->meth->is_on_curve(group, point, ctx);
 860 }
 861
 862 int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b,
 863                  BN_CTX *ctx)
 864 {
 865     if (group->meth->point_cmp == 0) {
 866         ECerr(EC_F_EC_POINT_CMP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 867         return -1;
 868     }
 869     if (!ec_point_is_compat(a, group) || !ec_point_is_compat(b, group)) {
 870         ECerr(EC_F_EC_POINT_CMP, EC_R_INCOMPATIBLE_OBJECTS);
 871         return -1;
 872     }
 873     return group->meth->point_cmp(group, a, b, ctx);
 874 }
 875
 876 int EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
 877 {
 878     if (group->meth->make_affine == 0) {
 879         ECerr(EC_F_EC_POINT_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 880         return 0;
 881     }
 882     if (!ec_point_is_compat(point, group)) {
 883         ECerr(EC_F_EC_POINT_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
 884         return 0;
 885     }
 886     return group->meth->make_affine(group, point, ctx);
 887 }
 888
 889 int EC_POINTs_make_affine(const EC_GROUP *group, size_t num,
 890                           EC_POINT *points[], BN_CTX *ctx)
 891 {
 892     size_t i;
 893
 894     if (group->meth->points_make_affine == 0) {
 895         ECerr(EC_F_EC_POINTS_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 896         return 0;
 897     }
 898     for (i = 0; i < num; i++) {
 899         if (!ec_point_is_compat(points[i], group)) {
 900             ECerr(EC_F_EC_POINTS_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
 901             return 0;
 902         }
 903     }
 904     return group->meth->points_make_affine(group, num, points, ctx);
 905 }
 906
 907 /*
 908  * Functions for point multiplication. If group->meth->mul is 0, we use the
 909  * wNAF-based implementations in ec_mult.c; otherwise we dispatch through
 910  * methods.
 911  */
 912
 913 int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
 914                   size_t num, const EC_POINT *points[],
 915                   const BIGNUM *scalars[], BN_CTX *ctx)
 916 {
 917     int ret = 0;
 918     size_t i = 0;
 919     BN_CTX *new_ctx = NULL;
 920
 921     if ((scalar == NULL) && (num == 0)) {
 922         return EC_POINT_set_to_infinity(group, r);
 923     }
 924
 925     if (!ec_point_is_compat(r, group)) {
 926         ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
 927         return 0;
 928     }
 929     for (i = 0; i < num; i++) {
 930         if (!ec_point_is_compat(points[i], group)) {
 931             ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
 932             return 0;
 933         }
 934     }
 935
 936     if (ctx == NULL && (ctx = new_ctx = BN_CTX_secure_new()) == NULL) {
 937         ECerr(EC_F_EC_POINTS_MUL, ERR_R_INTERNAL_ERROR);
 938         return 0;
 939     }
 940
 941     if (group->meth->mul != NULL)
 942         ret = group->meth->mul(group, r, scalar, num, points, scalars, ctx);
 943     else
 944         /* use default */
 945         ret = ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
 946
 947     BN_CTX_free(new_ctx);
 948     return ret;
 949 }
 950
 951 int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
 952                  const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx)
 953 {
 954     /* just a convenient interface to EC_POINTs_mul() */
 955
 956     const EC_POINT *points[1];
 957     const BIGNUM *scalars[1];
 958
 959     points[0] = point;
 960     scalars[0] = p_scalar;
 961
 962     return EC_POINTs_mul(group, r, g_scalar,
 963                          (point != NULL
 964                           && p_scalar != NULL), points, scalars, ctx);
 965 }
 966
 967 int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
 968 {
 969     if (group->meth->mul == 0)
 970         /* use default */
 971         return ec_wNAF_precompute_mult(group, ctx);
 972
 973     if (group->meth->precompute_mult != 0)
 974         return group->meth->precompute_mult(group, ctx);
 975     else
 976         return 1;               /* nothing to do, so report success */
 977 }
 978
 979 int EC_GROUP_have_precompute_mult(const EC_GROUP *group)
 980 {
 981     if (group->meth->mul == 0)
 982         /* use default */
 983         return ec_wNAF_have_precompute_mult(group);
 984
 985     if (group->meth->have_precompute_mult != 0)
 986         return group->meth->have_precompute_mult(group);
 987     else
 988         return 0;               /* cannot tell whether precomputation has
 989                                  * been performed */
 990 }
 991
 992 /*
 993  * ec_precompute_mont_data sets |group->mont_data| from |group->order| and
 994  * returns one on success. On error it returns zero.
 995  */
 996 static int ec_precompute_mont_data(EC_GROUP *group)
 997 {
 998     BN_CTX *ctx = BN_CTX_new();
 999     int ret = 0;
1000
1001     BN_MONT_CTX_free(group->mont_data);
1002     group->mont_data = NULL;
1003
1004     if (ctx == NULL)
1005         goto err;
1006
1007     group->mont_data = BN_MONT_CTX_new();
1008     if (group->mont_data == NULL)
1009         goto err;
1010
1011     if (!BN_MONT_CTX_set(group->mont_data, group->order, ctx)) {
1012         BN_MONT_CTX_free(group->mont_data);
1013         group->mont_data = NULL;
1014         goto err;
1015     }
1016
1017     ret = 1;
1018
1019  err:
1020
1021     BN_CTX_free(ctx);
1022     return ret;
1023 }
1024
1025 int EC_KEY_set_ex_data(EC_KEY *key, int idx, void *arg)
1026 {
1027     return CRYPTO_set_ex_data(&key->ex_data, idx, arg);
1028 }
1029
1030 void *EC_KEY_get_ex_data(const EC_KEY *key, int idx)
1031 {
1032     return CRYPTO_get_ex_data(&key->ex_data, idx);
1033 }
1034
1035 int ec_group_simple_order_bits(const EC_GROUP *group)
1036 {
1037     if (group->order == NULL)
1038         return 0;
1039     return BN_num_bits(group->order);
1040 }
1041
1042 static int ec_field_inverse_mod_ord(const EC_GROUP *group, BIGNUM *r,
1043                                     const BIGNUM *x, BN_CTX *ctx)
1044 {
1045     BIGNUM *e = NULL;
1046     BN_CTX *new_ctx = NULL;
1047     int ret = 0;
1048
1049     if (group->mont_data == NULL)
1050         return 0;
1051
1052     if (ctx == NULL && (ctx = new_ctx = BN_CTX_secure_new()) == NULL)
1053         return 0;
1054
1055     BN_CTX_start(ctx);
1056     if ((e = BN_CTX_get(ctx)) == NULL)
1057         goto err;
1058
1059     /*-
1060      * We want inverse in constant time, therefore we utilize the fact
1061      * order must be prime and use Fermats Little Theorem instead.
1062      */
1063     if (!BN_set_word(e, 2))
1064         goto err;
1065     if (!BN_sub(e, group->order, e))
1066         goto err;
1067     /*-
1068      * Exponent e is public.
1069      * No need for scatter-gather or BN_FLG_CONSTTIME.
1070      */
1071     if (!BN_mod_exp_mont(r, x, e, group->order, ctx, group->mont_data))
1072         goto err;
1073
1074     ret = 1;
1075
1076  err:
1077     if (ctx != NULL)
1078         BN_CTX_end(ctx);
1079     BN_CTX_free(new_ctx);
1080     return ret;
1081 }
1082
1083 /*-
1084  * Default behavior, if group->meth->field_inverse_mod_ord is NULL:
1085  * - When group->order is even, this function returns an error.
1086  * - When group->order is otherwise composite, the correctness
1087  *   of the output is not guaranteed.
1088  * - When x is outside the range [1, group->order), the correctness
1089  *   of the output is not guaranteed.
1090  * - Otherwise, this function returns the multiplicative inverse in the
1091  *   range [1, group->order).
1092  *
1093  * EC_METHODs must implement their own field_inverse_mod_ord for
1094  * other functionality.
1095  */
1096 int ec_group_do_inverse_ord(const EC_GROUP *group, BIGNUM *res,
1097                             const BIGNUM *x, BN_CTX *ctx)
1098 {
1099     if (group->meth->field_inverse_mod_ord != NULL)
1100         return group->meth->field_inverse_mod_ord(group, res, x, ctx);
1101     else
1102         return ec_field_inverse_mod_ord(group, res, x, ctx);
1103 }
1104
1105 /*-
1106  * Coordinate blinding for EC_POINT.
1107  *
1108  * The underlying EC_METHOD can optionally implement this function:
1109  * underlying implementations should return 0 on errors, or 1 on
1110  * success.
1111  *
1112  * This wrapper returns 1 in case the underlying EC_METHOD does not
1113  * support coordinate blinding.
1114  */
1115 int ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx)
1116 {
1117     if (group->meth->blind_coordinates == NULL)
1118         return 1; /* ignore if not implemented */
1119
1120     return group->meth->blind_coordinates(group, p, ctx);
1121 }