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 Apache License 2.0 (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 const BIGNUM *EC_GROUP_get0_field(const EC_GROUP *group)
 368 {
 369     return group->field;
 370 }
 371
 372 void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag)
 373 {
 374     group->asn1_flag = flag;
 375 }
 376
 377 int EC_GROUP_get_asn1_flag(const EC_GROUP *group)
 378 {
 379     return group->asn1_flag;
 380 }
 381
 382 void EC_GROUP_set_point_conversion_form(EC_GROUP *group,
 383                                         point_conversion_form_t form)
 384 {
 385     group->asn1_form = form;
 386 }
 387
 388 point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP
 389                                                            *group)
 390 {
 391     return group->asn1_form;
 392 }
 393
 394 size_t EC_GROUP_set_seed(EC_GROUP *group, const unsigned char *p, size_t len)
 395 {
 396     OPENSSL_free(group->seed);
 397     group->seed = NULL;
 398     group->seed_len = 0;
 399
 400     if (!len || !p)
 401         return 1;
 402
 403     if ((group->seed = OPENSSL_malloc(len)) == NULL) {
 404         ECerr(EC_F_EC_GROUP_SET_SEED, ERR_R_MALLOC_FAILURE);
 405         return 0;
 406     }
 407     memcpy(group->seed, p, len);
 408     group->seed_len = len;
 409
 410     return len;
 411 }
 412
 413 unsigned char *EC_GROUP_get0_seed(const EC_GROUP *group)
 414 {
 415     return group->seed;
 416 }
 417
 418 size_t EC_GROUP_get_seed_len(const EC_GROUP *group)
 419 {
 420     return group->seed_len;
 421 }
 422
 423 int EC_GROUP_set_curve(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
 424                        const BIGNUM *b, BN_CTX *ctx)
 425 {
 426     if (group->meth->group_set_curve == 0) {
 427         ECerr(EC_F_EC_GROUP_SET_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 428         return 0;
 429     }
 430     return group->meth->group_set_curve(group, p, a, b, ctx);
 431 }
 432
 433 int EC_GROUP_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b,
 434                        BN_CTX *ctx)
 435 {
 436     if (group->meth->group_get_curve == NULL) {
 437         ECerr(EC_F_EC_GROUP_GET_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 438         return 0;
 439     }
 440     return group->meth->group_get_curve(group, p, a, b, ctx);
 441 }
 442
 443 #if !OPENSSL_API_3
 444 int EC_GROUP_set_curve_GFp(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
 445                            const BIGNUM *b, BN_CTX *ctx)
 446 {
 447     return EC_GROUP_set_curve(group, p, a, b, ctx);
 448 }
 449
 450 int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
 451                            BIGNUM *b, BN_CTX *ctx)
 452 {
 453     return EC_GROUP_get_curve(group, p, a, b, ctx);
 454 }
 455
 456 # ifndef OPENSSL_NO_EC2M
 457 int EC_GROUP_set_curve_GF2m(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
 458                             const BIGNUM *b, BN_CTX *ctx)
 459 {
 460     return EC_GROUP_set_curve(group, p, a, b, ctx);
 461 }
 462
 463 int EC_GROUP_get_curve_GF2m(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
 464                             BIGNUM *b, BN_CTX *ctx)
 465 {
 466     return EC_GROUP_get_curve(group, p, a, b, ctx);
 467 }
 468 # endif
 469 #endif
 470
 471 int EC_GROUP_get_degree(const EC_GROUP *group)
 472 {
 473     if (group->meth->group_get_degree == 0) {
 474         ECerr(EC_F_EC_GROUP_GET_DEGREE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 475         return 0;
 476     }
 477     return group->meth->group_get_degree(group);
 478 }
 479
 480 int EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
 481 {
 482     if (group->meth->group_check_discriminant == 0) {
 483         ECerr(EC_F_EC_GROUP_CHECK_DISCRIMINANT,
 484               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 485         return 0;
 486     }
 487     return group->meth->group_check_discriminant(group, ctx);
 488 }
 489
 490 int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ctx)
 491 {
 492     int r = 0;
 493     BIGNUM *a1, *a2, *a3, *b1, *b2, *b3;
 494     BN_CTX *ctx_new = NULL;
 495
 496     /* compare the field types */
 497     if (EC_METHOD_get_field_type(EC_GROUP_method_of(a)) !=
 498         EC_METHOD_get_field_type(EC_GROUP_method_of(b)))
 499         return 1;
 500     /* compare the curve name (if present in both) */
 501     if (EC_GROUP_get_curve_name(a) && EC_GROUP_get_curve_name(b) &&
 502         EC_GROUP_get_curve_name(a) != EC_GROUP_get_curve_name(b))
 503         return 1;
 504     if (a->meth->flags & EC_FLAGS_CUSTOM_CURVE)
 505         return 0;
 506
 507     if (ctx == NULL)
 508         ctx_new = ctx = BN_CTX_new();
 509     if (ctx == NULL)
 510         return -1;
 511
 512     BN_CTX_start(ctx);
 513     a1 = BN_CTX_get(ctx);
 514     a2 = BN_CTX_get(ctx);
 515     a3 = BN_CTX_get(ctx);
 516     b1 = BN_CTX_get(ctx);
 517     b2 = BN_CTX_get(ctx);
 518     b3 = BN_CTX_get(ctx);
 519     if (b3 == NULL) {
 520         BN_CTX_end(ctx);
 521         BN_CTX_free(ctx_new);
 522         return -1;
 523     }
 524
 525     /*
 526      * XXX This approach assumes that the external representation of curves
 527      * over the same field type is the same.
 528      */
 529     if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) ||
 530         !b->meth->group_get_curve(b, b1, b2, b3, ctx))
 531         r = 1;
 532
 533     if (r || BN_cmp(a1, b1) || BN_cmp(a2, b2) || BN_cmp(a3, b3))
 534         r = 1;
 535
 536     /* XXX EC_POINT_cmp() assumes that the methods are equal */
 537     if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a),
 538                           EC_GROUP_get0_generator(b), ctx))
 539         r = 1;
 540
 541     if (!r) {
 542         const BIGNUM *ao, *bo, *ac, *bc;
 543         /* compare the order and cofactor */
 544         ao = EC_GROUP_get0_order(a);
 545         bo = EC_GROUP_get0_order(b);
 546         ac = EC_GROUP_get0_cofactor(a);
 547         bc = EC_GROUP_get0_cofactor(b);
 548         if (ao == NULL || bo == NULL) {
 549             BN_CTX_end(ctx);
 550             BN_CTX_free(ctx_new);
 551             return -1;
 552         }
 553         if (BN_cmp(ao, bo) || BN_cmp(ac, bc))
 554             r = 1;
 555     }
 556
 557     BN_CTX_end(ctx);
 558     BN_CTX_free(ctx_new);
 559
 560     return r;
 561 }
 562
 563 /* functions for EC_POINT objects */
 564
 565 EC_POINT *EC_POINT_new(const EC_GROUP *group)
 566 {
 567     EC_POINT *ret;
 568
 569     if (group == NULL) {
 570         ECerr(EC_F_EC_POINT_NEW, ERR_R_PASSED_NULL_PARAMETER);
 571         return NULL;
 572     }
 573     if (group->meth->point_init == NULL) {
 574         ECerr(EC_F_EC_POINT_NEW, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 575         return NULL;
 576     }
 577
 578     ret = OPENSSL_zalloc(sizeof(*ret));
 579     if (ret == NULL) {
 580         ECerr(EC_F_EC_POINT_NEW, ERR_R_MALLOC_FAILURE);
 581         return NULL;
 582     }
 583
 584     ret->meth = group->meth;
 585     ret->curve_name = group->curve_name;
 586
 587     if (!ret->meth->point_init(ret)) {
 588         OPENSSL_free(ret);
 589         return NULL;
 590     }
 591
 592     return ret;
 593 }
 594
 595 void EC_POINT_free(EC_POINT *point)
 596 {
 597     if (!point)
 598         return;
 599
 600     if (point->meth->point_finish != 0)
 601         point->meth->point_finish(point);
 602     OPENSSL_free(point);
 603 }
 604
 605 void EC_POINT_clear_free(EC_POINT *point)
 606 {
 607     if (!point)
 608         return;
 609
 610     if (point->meth->point_clear_finish != 0)
 611         point->meth->point_clear_finish(point);
 612     else if (point->meth->point_finish != 0)
 613         point->meth->point_finish(point);
 614     OPENSSL_clear_free(point, sizeof(*point));
 615 }
 616
 617 int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src)
 618 {
 619     if (dest->meth->point_copy == 0) {
 620         ECerr(EC_F_EC_POINT_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 621         return 0;
 622     }
 623     if (dest->meth != src->meth
 624             || (dest->curve_name != src->curve_name
 625                 && dest->curve_name != 0
 626                 && src->curve_name != 0)) {
 627         ECerr(EC_F_EC_POINT_COPY, EC_R_INCOMPATIBLE_OBJECTS);
 628         return 0;
 629     }
 630     if (dest == src)
 631         return 1;
 632     return dest->meth->point_copy(dest, src);
 633 }
 634
 635 EC_POINT *EC_POINT_dup(const EC_POINT *a, const EC_GROUP *group)
 636 {
 637     EC_POINT *t;
 638     int r;
 639
 640     if (a == NULL)
 641         return NULL;
 642
 643     t = EC_POINT_new(group);
 644     if (t == NULL)
 645         return NULL;
 646     r = EC_POINT_copy(t, a);
 647     if (!r) {
 648         EC_POINT_free(t);
 649         return NULL;
 650     }
 651     return t;
 652 }
 653
 654 const EC_METHOD *EC_POINT_method_of(const EC_POINT *point)
 655 {
 656     return point->meth;
 657 }
 658
 659 int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
 660 {
 661     if (group->meth->point_set_to_infinity == 0) {
 662         ECerr(EC_F_EC_POINT_SET_TO_INFINITY,
 663               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 664         return 0;
 665     }
 666     if (group->meth != point->meth) {
 667         ECerr(EC_F_EC_POINT_SET_TO_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
 668         return 0;
 669     }
 670     return group->meth->point_set_to_infinity(group, point);
 671 }
 672
 673 int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
 674                                              EC_POINT *point, const BIGNUM *x,
 675                                              const BIGNUM *y, const BIGNUM *z,
 676                                              BN_CTX *ctx)
 677 {
 678     if (group->meth->point_set_Jprojective_coordinates_GFp == 0) {
 679         ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP,
 680               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 681         return 0;
 682     }
 683     if (!ec_point_is_compat(point, group)) {
 684         ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP,
 685               EC_R_INCOMPATIBLE_OBJECTS);
 686         return 0;
 687     }
 688     return group->meth->point_set_Jprojective_coordinates_GFp(group, point, x,
 689                                                               y, z, ctx);
 690 }
 691
 692 int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
 693                                              const EC_POINT *point, BIGNUM *x,
 694                                              BIGNUM *y, BIGNUM *z,
 695                                              BN_CTX *ctx)
 696 {
 697     if (group->meth->point_get_Jprojective_coordinates_GFp == 0) {
 698         ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP,
 699               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 700         return 0;
 701     }
 702     if (!ec_point_is_compat(point, group)) {
 703         ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP,
 704               EC_R_INCOMPATIBLE_OBJECTS);
 705         return 0;
 706     }
 707     return group->meth->point_get_Jprojective_coordinates_GFp(group, point, x,
 708                                                               y, z, ctx);
 709 }
 710
 711 int EC_POINT_set_affine_coordinates(const EC_GROUP *group, EC_POINT *point,
 712                                     const BIGNUM *x, const BIGNUM *y,
 713                                     BN_CTX *ctx)
 714 {
 715     if (group->meth->point_set_affine_coordinates == NULL) {
 716         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES,
 717               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 718         return 0;
 719     }
 720     if (!ec_point_is_compat(point, group)) {
 721         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES, EC_R_INCOMPATIBLE_OBJECTS);
 722         return 0;
 723     }
 724     if (!group->meth->point_set_affine_coordinates(group, point, x, y, ctx))
 725         return 0;
 726
 727     if (EC_POINT_is_on_curve(group, point, ctx) <= 0) {
 728         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES, EC_R_POINT_IS_NOT_ON_CURVE);
 729         return 0;
 730     }
 731     return 1;
 732 }
 733
 734 #if !OPENSSL_API_3
 735 int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group,
 736                                         EC_POINT *point, const BIGNUM *x,
 737                                         const BIGNUM *y, BN_CTX *ctx)
 738 {
 739     return EC_POINT_set_affine_coordinates(group, point, x, y, ctx);
 740 }
 741
 742 # ifndef OPENSSL_NO_EC2M
 743 int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group,
 744                                          EC_POINT *point, const BIGNUM *x,
 745                                          const BIGNUM *y, BN_CTX *ctx)
 746 {
 747     return EC_POINT_set_affine_coordinates(group, point, x, y, ctx);
 748 }
 749 # endif
 750 #endif
 751
 752 int EC_POINT_get_affine_coordinates(const EC_GROUP *group,
 753                                     const EC_POINT *point, BIGNUM *x, BIGNUM *y,
 754                                     BN_CTX *ctx)
 755 {
 756     if (group->meth->point_get_affine_coordinates == NULL) {
 757         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES,
 758               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 759         return 0;
 760     }
 761     if (!ec_point_is_compat(point, group)) {
 762         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES, EC_R_INCOMPATIBLE_OBJECTS);
 763         return 0;
 764     }
 765     if (EC_POINT_is_at_infinity(group, point)) {
 766         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES, EC_R_POINT_AT_INFINITY);
 767         return 0;
 768     }
 769     return group->meth->point_get_affine_coordinates(group, point, x, y, ctx);
 770 }
 771
 772 #if !OPENSSL_API_3
 773 int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group,
 774                                         const EC_POINT *point, BIGNUM *x,
 775                                         BIGNUM *y, BN_CTX *ctx)
 776 {
 777     return EC_POINT_get_affine_coordinates(group, point, x, y, ctx);
 778 }
 779
 780 # ifndef OPENSSL_NO_EC2M
 781 int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group,
 782                                          const EC_POINT *point, BIGNUM *x,
 783                                          BIGNUM *y, BN_CTX *ctx)
 784 {
 785     return EC_POINT_get_affine_coordinates(group, point, x, y, ctx);
 786 }
 787 # endif
 788 #endif
 789
 790 int EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
 791                  const EC_POINT *b, BN_CTX *ctx)
 792 {
 793     if (group->meth->add == 0) {
 794         ECerr(EC_F_EC_POINT_ADD, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 795         return 0;
 796     }
 797     if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group)
 798         || !ec_point_is_compat(b, group)) {
 799         ECerr(EC_F_EC_POINT_ADD, EC_R_INCOMPATIBLE_OBJECTS);
 800         return 0;
 801     }
 802     return group->meth->add(group, r, a, b, ctx);
 803 }
 804
 805 int EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
 806                  BN_CTX *ctx)
 807 {
 808     if (group->meth->dbl == 0) {
 809         ECerr(EC_F_EC_POINT_DBL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 810         return 0;
 811     }
 812     if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group)) {
 813         ECerr(EC_F_EC_POINT_DBL, EC_R_INCOMPATIBLE_OBJECTS);
 814         return 0;
 815     }
 816     return group->meth->dbl(group, r, a, ctx);
 817 }
 818
 819 int EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx)
 820 {
 821     if (group->meth->invert == 0) {
 822         ECerr(EC_F_EC_POINT_INVERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 823         return 0;
 824     }
 825     if (!ec_point_is_compat(a, group)) {
 826         ECerr(EC_F_EC_POINT_INVERT, EC_R_INCOMPATIBLE_OBJECTS);
 827         return 0;
 828     }
 829     return group->meth->invert(group, a, ctx);
 830 }
 831
 832 int EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
 833 {
 834     if (group->meth->is_at_infinity == 0) {
 835         ECerr(EC_F_EC_POINT_IS_AT_INFINITY,
 836               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 837         return 0;
 838     }
 839     if (!ec_point_is_compat(point, group)) {
 840         ECerr(EC_F_EC_POINT_IS_AT_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
 841         return 0;
 842     }
 843     return group->meth->is_at_infinity(group, point);
 844 }
 845
 846 /*
 847  * Check whether an EC_POINT is on the curve or not. Note that the return
 848  * value for this function should NOT be treated as a boolean. Return values:
 849  *  1: The point is on the curve
 850  *  0: The point is not on the curve
 851  * -1: An error occurred
 852  */
 853 int EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
 854                          BN_CTX *ctx)
 855 {
 856     if (group->meth->is_on_curve == 0) {
 857         ECerr(EC_F_EC_POINT_IS_ON_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 858         return 0;
 859     }
 860     if (!ec_point_is_compat(point, group)) {
 861         ECerr(EC_F_EC_POINT_IS_ON_CURVE, EC_R_INCOMPATIBLE_OBJECTS);
 862         return 0;
 863     }
 864     return group->meth->is_on_curve(group, point, ctx);
 865 }
 866
 867 int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b,
 868                  BN_CTX *ctx)
 869 {
 870     if (group->meth->point_cmp == 0) {
 871         ECerr(EC_F_EC_POINT_CMP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 872         return -1;
 873     }
 874     if (!ec_point_is_compat(a, group) || !ec_point_is_compat(b, group)) {
 875         ECerr(EC_F_EC_POINT_CMP, EC_R_INCOMPATIBLE_OBJECTS);
 876         return -1;
 877     }
 878     return group->meth->point_cmp(group, a, b, ctx);
 879 }
 880
 881 int EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
 882 {
 883     if (group->meth->make_affine == 0) {
 884         ECerr(EC_F_EC_POINT_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 885         return 0;
 886     }
 887     if (!ec_point_is_compat(point, group)) {
 888         ECerr(EC_F_EC_POINT_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
 889         return 0;
 890     }
 891     return group->meth->make_affine(group, point, ctx);
 892 }
 893
 894 int EC_POINTs_make_affine(const EC_GROUP *group, size_t num,
 895                           EC_POINT *points[], BN_CTX *ctx)
 896 {
 897     size_t i;
 898
 899     if (group->meth->points_make_affine == 0) {
 900         ECerr(EC_F_EC_POINTS_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 901         return 0;
 902     }
 903     for (i = 0; i < num; i++) {
 904         if (!ec_point_is_compat(points[i], group)) {
 905             ECerr(EC_F_EC_POINTS_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
 906             return 0;
 907         }
 908     }
 909     return group->meth->points_make_affine(group, num, points, ctx);
 910 }
 911
 912 /*
 913  * Functions for point multiplication. If group->meth->mul is 0, we use the
 914  * wNAF-based implementations in ec_mult.c; otherwise we dispatch through
 915  * methods.
 916  */
 917
 918 int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
 919                   size_t num, const EC_POINT *points[],
 920                   const BIGNUM *scalars[], BN_CTX *ctx)
 921 {
 922     int ret = 0;
 923     size_t i = 0;
 924     BN_CTX *new_ctx = NULL;
 925
 926     if ((scalar == NULL) && (num == 0)) {
 927         return EC_POINT_set_to_infinity(group, r);
 928     }
 929
 930     if (!ec_point_is_compat(r, group)) {
 931         ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
 932         return 0;
 933     }
 934     for (i = 0; i < num; i++) {
 935         if (!ec_point_is_compat(points[i], group)) {
 936             ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
 937             return 0;
 938         }
 939     }
 940
 941     if (ctx == NULL && (ctx = new_ctx = BN_CTX_secure_new()) == NULL) {
 942         ECerr(EC_F_EC_POINTS_MUL, ERR_R_INTERNAL_ERROR);
 943         return 0;
 944     }
 945
 946     if (group->meth->mul != NULL)
 947         ret = group->meth->mul(group, r, scalar, num, points, scalars, ctx);
 948     else
 949         /* use default */
 950         ret = ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
 951
 952     BN_CTX_free(new_ctx);
 953     return ret;
 954 }
 955
 956 int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
 957                  const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx)
 958 {
 959     /* just a convenient interface to EC_POINTs_mul() */
 960
 961     const EC_POINT *points[1];
 962     const BIGNUM *scalars[1];
 963
 964     points[0] = point;
 965     scalars[0] = p_scalar;
 966
 967     return EC_POINTs_mul(group, r, g_scalar,
 968                          (point != NULL
 969                           && p_scalar != NULL), points, scalars, ctx);
 970 }
 971
 972 int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
 973 {
 974     if (group->meth->mul == 0)
 975         /* use default */
 976         return ec_wNAF_precompute_mult(group, ctx);
 977
 978     if (group->meth->precompute_mult != 0)
 979         return group->meth->precompute_mult(group, ctx);
 980     else
 981         return 1;               /* nothing to do, so report success */
 982 }
 983
 984 int EC_GROUP_have_precompute_mult(const EC_GROUP *group)
 985 {
 986     if (group->meth->mul == 0)
 987         /* use default */
 988         return ec_wNAF_have_precompute_mult(group);
 989
 990     if (group->meth->have_precompute_mult != 0)
 991         return group->meth->have_precompute_mult(group);
 992     else
 993         return 0;               /* cannot tell whether precomputation has
 994                                  * been performed */
 995 }
 996
 997 /*
 998  * ec_precompute_mont_data sets |group->mont_data| from |group->order| and
 999  * returns one on success. On error it returns zero.
1000  */
1001 static int ec_precompute_mont_data(EC_GROUP *group)
1002 {
1003     BN_CTX *ctx = BN_CTX_new();
1004     int ret = 0;
1005
1006     BN_MONT_CTX_free(group->mont_data);
1007     group->mont_data = NULL;
1008
1009     if (ctx == NULL)
1010         goto err;
1011
1012     group->mont_data = BN_MONT_CTX_new();
1013     if (group->mont_data == NULL)
1014         goto err;
1015
1016     if (!BN_MONT_CTX_set(group->mont_data, group->order, ctx)) {
1017         BN_MONT_CTX_free(group->mont_data);
1018         group->mont_data = NULL;
1019         goto err;
1020     }
1021
1022     ret = 1;
1023
1024  err:
1025
1026     BN_CTX_free(ctx);
1027     return ret;
1028 }
1029
1030 int EC_KEY_set_ex_data(EC_KEY *key, int idx, void *arg)
1031 {
1032     return CRYPTO_set_ex_data(&key->ex_data, idx, arg);
1033 }
1034
1035 void *EC_KEY_get_ex_data(const EC_KEY *key, int idx)
1036 {
1037     return CRYPTO_get_ex_data(&key->ex_data, idx);
1038 }
1039
1040 int ec_group_simple_order_bits(const EC_GROUP *group)
1041 {
1042     if (group->order == NULL)
1043         return 0;
1044     return BN_num_bits(group->order);
1045 }
1046
1047 static int ec_field_inverse_mod_ord(const EC_GROUP *group, BIGNUM *r,
1048                                     const BIGNUM *x, BN_CTX *ctx)
1049 {
1050     BIGNUM *e = NULL;
1051     BN_CTX *new_ctx = NULL;
1052     int ret = 0;
1053
1054     if (group->mont_data == NULL)
1055         return 0;
1056
1057     if (ctx == NULL && (ctx = new_ctx = BN_CTX_secure_new()) == NULL)
1058         return 0;
1059
1060     BN_CTX_start(ctx);
1061     if ((e = BN_CTX_get(ctx)) == NULL)
1062         goto err;
1063
1064     /*-
1065      * We want inverse in constant time, therefore we utilize the fact
1066      * order must be prime and use Fermats Little Theorem instead.
1067      */
1068     if (!BN_set_word(e, 2))
1069         goto err;
1070     if (!BN_sub(e, group->order, e))
1071         goto err;
1072     /*-
1073      * Exponent e is public.
1074      * No need for scatter-gather or BN_FLG_CONSTTIME.
1075      */
1076     if (!BN_mod_exp_mont(r, x, e, group->order, ctx, group->mont_data))
1077         goto err;
1078
1079     ret = 1;
1080
1081  err:
1082     BN_CTX_end(ctx);
1083     BN_CTX_free(new_ctx);
1084     return ret;
1085 }
1086
1087 /*-
1088  * Default behavior, if group->meth->field_inverse_mod_ord is NULL:
1089  * - When group->order is even, this function returns an error.
1090  * - When group->order is otherwise composite, the correctness
1091  *   of the output is not guaranteed.
1092  * - When x is outside the range [1, group->order), the correctness
1093  *   of the output is not guaranteed.
1094  * - Otherwise, this function returns the multiplicative inverse in the
1095  *   range [1, group->order).
1096  *
1097  * EC_METHODs must implement their own field_inverse_mod_ord for
1098  * other functionality.
1099  */
1100 int ec_group_do_inverse_ord(const EC_GROUP *group, BIGNUM *res,
1101                             const BIGNUM *x, BN_CTX *ctx)
1102 {
1103     if (group->meth->field_inverse_mod_ord != NULL)
1104         return group->meth->field_inverse_mod_ord(group, res, x, ctx);
1105     else
1106         return ec_field_inverse_mod_ord(group, res, x, ctx);
1107 }
1108
1109 /*-
1110  * Coordinate blinding for EC_POINT.
1111  *
1112  * The underlying EC_METHOD can optionally implement this function:
1113  * underlying implementations should return 0 on errors, or 1 on
1114  * success.
1115  *
1116  * This wrapper returns 1 in case the underlying EC_METHOD does not
1117  * support coordinate blinding.
1118  */
1119 int ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx)
1120 {
1121     if (group->meth->blind_coordinates == NULL)
1122         return 1; /* ignore if not implemented */
1123
1124     return group->meth->blind_coordinates(group, p, ctx);
1125 }