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_GFp(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_GFP, 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_GFp(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
 429                            BIGNUM *b, BN_CTX *ctx)
 430 {
 431     if (group->meth->group_get_curve == 0) {
 432         ECerr(EC_F_EC_GROUP_GET_CURVE_GFP, 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 #ifndef OPENSSL_NO_EC2M
 439 int EC_GROUP_set_curve_GF2m(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
 440                             const BIGNUM *b, BN_CTX *ctx)
 441 {
 442     if (group->meth->group_set_curve == 0) {
 443         ECerr(EC_F_EC_GROUP_SET_CURVE_GF2M,
 444               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 445         return 0;
 446     }
 447     return group->meth->group_set_curve(group, p, a, b, ctx);
 448 }
 449
 450 int EC_GROUP_get_curve_GF2m(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
 451                             BIGNUM *b, BN_CTX *ctx)
 452 {
 453     if (group->meth->group_get_curve == 0) {
 454         ECerr(EC_F_EC_GROUP_GET_CURVE_GF2M,
 455               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 456         return 0;
 457     }
 458     return group->meth->group_get_curve(group, p, a, b, ctx);
 459 }
 460 #endif
 461
 462 int EC_GROUP_get_degree(const EC_GROUP *group)
 463 {
 464     if (group->meth->group_get_degree == 0) {
 465         ECerr(EC_F_EC_GROUP_GET_DEGREE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 466         return 0;
 467     }
 468     return group->meth->group_get_degree(group);
 469 }
 470
 471 int EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
 472 {
 473     if (group->meth->group_check_discriminant == 0) {
 474         ECerr(EC_F_EC_GROUP_CHECK_DISCRIMINANT,
 475               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 476         return 0;
 477     }
 478     return group->meth->group_check_discriminant(group, ctx);
 479 }
 480
 481 int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ctx)
 482 {
 483     int r = 0;
 484     BIGNUM *a1, *a2, *a3, *b1, *b2, *b3;
 485     BN_CTX *ctx_new = NULL;
 486
 487     /* compare the field types */
 488     if (EC_METHOD_get_field_type(EC_GROUP_method_of(a)) !=
 489         EC_METHOD_get_field_type(EC_GROUP_method_of(b)))
 490         return 1;
 491     /* compare the curve name (if present in both) */
 492     if (EC_GROUP_get_curve_name(a) && EC_GROUP_get_curve_name(b) &&
 493         EC_GROUP_get_curve_name(a) != EC_GROUP_get_curve_name(b))
 494         return 1;
 495     if (a->meth->flags & EC_FLAGS_CUSTOM_CURVE)
 496         return 0;
 497
 498     if (ctx == NULL)
 499         ctx_new = ctx = BN_CTX_new();
 500     if (ctx == NULL)
 501         return -1;
 502
 503     BN_CTX_start(ctx);
 504     a1 = BN_CTX_get(ctx);
 505     a2 = BN_CTX_get(ctx);
 506     a3 = BN_CTX_get(ctx);
 507     b1 = BN_CTX_get(ctx);
 508     b2 = BN_CTX_get(ctx);
 509     b3 = BN_CTX_get(ctx);
 510     if (b3 == NULL) {
 511         BN_CTX_end(ctx);
 512         BN_CTX_free(ctx_new);
 513         return -1;
 514     }
 515
 516     /*
 517      * XXX This approach assumes that the external representation of curves
 518      * over the same field type is the same.
 519      */
 520     if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) ||
 521         !b->meth->group_get_curve(b, b1, b2, b3, ctx))
 522         r = 1;
 523
 524     if (r || BN_cmp(a1, b1) || BN_cmp(a2, b2) || BN_cmp(a3, b3))
 525         r = 1;
 526
 527     /* XXX EC_POINT_cmp() assumes that the methods are equal */
 528     if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a),
 529                           EC_GROUP_get0_generator(b), ctx))
 530         r = 1;
 531
 532     if (!r) {
 533         const BIGNUM *ao, *bo, *ac, *bc;
 534         /* compare the order and cofactor */
 535         ao = EC_GROUP_get0_order(a);
 536         bo = EC_GROUP_get0_order(b);
 537         ac = EC_GROUP_get0_cofactor(a);
 538         bc = EC_GROUP_get0_cofactor(b);
 539         if (ao == NULL || bo == NULL) {
 540             BN_CTX_end(ctx);
 541             BN_CTX_free(ctx_new);
 542             return -1;
 543         }
 544         if (BN_cmp(ao, bo) || BN_cmp(ac, bc))
 545             r = 1;
 546     }
 547
 548     BN_CTX_end(ctx);
 549     BN_CTX_free(ctx_new);
 550
 551     return r;
 552 }
 553
 554 /* functions for EC_POINT objects */
 555
 556 EC_POINT *EC_POINT_new(const EC_GROUP *group)
 557 {
 558     EC_POINT *ret;
 559
 560     if (group == NULL) {
 561         ECerr(EC_F_EC_POINT_NEW, ERR_R_PASSED_NULL_PARAMETER);
 562         return NULL;
 563     }
 564     if (group->meth->point_init == NULL) {
 565         ECerr(EC_F_EC_POINT_NEW, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 566         return NULL;
 567     }
 568
 569     ret = OPENSSL_zalloc(sizeof(*ret));
 570     if (ret == NULL) {
 571         ECerr(EC_F_EC_POINT_NEW, ERR_R_MALLOC_FAILURE);
 572         return NULL;
 573     }
 574
 575     ret->meth = group->meth;
 576     ret->curve_name = group->curve_name;
 577
 578     if (!ret->meth->point_init(ret)) {
 579         OPENSSL_free(ret);
 580         return NULL;
 581     }
 582
 583     return ret;
 584 }
 585
 586 void EC_POINT_free(EC_POINT *point)
 587 {
 588     if (!point)
 589         return;
 590
 591     if (point->meth->point_finish != 0)
 592         point->meth->point_finish(point);
 593     OPENSSL_free(point);
 594 }
 595
 596 void EC_POINT_clear_free(EC_POINT *point)
 597 {
 598     if (!point)
 599         return;
 600
 601     if (point->meth->point_clear_finish != 0)
 602         point->meth->point_clear_finish(point);
 603     else if (point->meth->point_finish != 0)
 604         point->meth->point_finish(point);
 605     OPENSSL_clear_free(point, sizeof(*point));
 606 }
 607
 608 int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src)
 609 {
 610     if (dest->meth->point_copy == 0) {
 611         ECerr(EC_F_EC_POINT_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 612         return 0;
 613     }
 614     if (dest->meth != src->meth
 615             || (dest->curve_name != src->curve_name
 616                 && dest->curve_name != 0
 617                 && src->curve_name != 0)) {
 618         ECerr(EC_F_EC_POINT_COPY, EC_R_INCOMPATIBLE_OBJECTS);
 619         return 0;
 620     }
 621     if (dest == src)
 622         return 1;
 623     return dest->meth->point_copy(dest, src);
 624 }
 625
 626 EC_POINT *EC_POINT_dup(const EC_POINT *a, const EC_GROUP *group)
 627 {
 628     EC_POINT *t;
 629     int r;
 630
 631     if (a == NULL)
 632         return NULL;
 633
 634     t = EC_POINT_new(group);
 635     if (t == NULL)
 636         return NULL;
 637     r = EC_POINT_copy(t, a);
 638     if (!r) {
 639         EC_POINT_free(t);
 640         return NULL;
 641     }
 642     return t;
 643 }
 644
 645 const EC_METHOD *EC_POINT_method_of(const EC_POINT *point)
 646 {
 647     return point->meth;
 648 }
 649
 650 int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
 651 {
 652     if (group->meth->point_set_to_infinity == 0) {
 653         ECerr(EC_F_EC_POINT_SET_TO_INFINITY,
 654               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 655         return 0;
 656     }
 657     if (group->meth != point->meth) {
 658         ECerr(EC_F_EC_POINT_SET_TO_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
 659         return 0;
 660     }
 661     return group->meth->point_set_to_infinity(group, point);
 662 }
 663
 664 int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
 665                                              EC_POINT *point, const BIGNUM *x,
 666                                              const BIGNUM *y, const BIGNUM *z,
 667                                              BN_CTX *ctx)
 668 {
 669     if (group->meth->point_set_Jprojective_coordinates_GFp == 0) {
 670         ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP,
 671               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 672         return 0;
 673     }
 674     if (!ec_point_is_compat(point, group)) {
 675         ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP,
 676               EC_R_INCOMPATIBLE_OBJECTS);
 677         return 0;
 678     }
 679     return group->meth->point_set_Jprojective_coordinates_GFp(group, point, x,
 680                                                               y, z, ctx);
 681 }
 682
 683 int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
 684                                              const EC_POINT *point, BIGNUM *x,
 685                                              BIGNUM *y, BIGNUM *z,
 686                                              BN_CTX *ctx)
 687 {
 688     if (group->meth->point_get_Jprojective_coordinates_GFp == 0) {
 689         ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP,
 690               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 691         return 0;
 692     }
 693     if (!ec_point_is_compat(point, group)) {
 694         ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP,
 695               EC_R_INCOMPATIBLE_OBJECTS);
 696         return 0;
 697     }
 698     return group->meth->point_get_Jprojective_coordinates_GFp(group, point, x,
 699                                                               y, z, ctx);
 700 }
 701
 702 int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group,
 703                                         EC_POINT *point, const BIGNUM *x,
 704                                         const BIGNUM *y, BN_CTX *ctx)
 705 {
 706     if (group->meth->point_set_affine_coordinates == 0) {
 707         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GFP,
 708               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 709         return 0;
 710     }
 711     if (!ec_point_is_compat(point, group)) {
 712         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GFP,
 713               EC_R_INCOMPATIBLE_OBJECTS);
 714         return 0;
 715     }
 716     if (!group->meth->point_set_affine_coordinates(group, point, x, y, ctx))
 717         return 0;
 718
 719     if (EC_POINT_is_on_curve(group, point, ctx) <= 0) {
 720         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GFP,
 721               EC_R_POINT_IS_NOT_ON_CURVE);
 722         return 0;
 723     }
 724     return 1;
 725 }
 726
 727 #ifndef OPENSSL_NO_EC2M
 728 int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group,
 729                                          EC_POINT *point, const BIGNUM *x,
 730                                          const BIGNUM *y, BN_CTX *ctx)
 731 {
 732     if (group->meth->point_set_affine_coordinates == 0) {
 733         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GF2M,
 734               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 735         return 0;
 736     }
 737     if (!ec_point_is_compat(point, group)) {
 738         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GF2M,
 739               EC_R_INCOMPATIBLE_OBJECTS);
 740         return 0;
 741     }
 742     if (!group->meth->point_set_affine_coordinates(group, point, x, y, ctx))
 743         return 0;
 744
 745     if (EC_POINT_is_on_curve(group, point, ctx) <= 0) {
 746         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GF2M,
 747               EC_R_POINT_IS_NOT_ON_CURVE);
 748         return 0;
 749     }
 750     return 1;
 751 }
 752 #endif
 753
 754 int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group,
 755                                         const EC_POINT *point, BIGNUM *x,
 756                                         BIGNUM *y, BN_CTX *ctx)
 757 {
 758     if (group->meth->point_get_affine_coordinates == 0) {
 759         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES_GFP,
 760               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 761         return 0;
 762     }
 763     if (!ec_point_is_compat(point, group)) {
 764         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES_GFP,
 765               EC_R_INCOMPATIBLE_OBJECTS);
 766         return 0;
 767     }
 768     return group->meth->point_get_affine_coordinates(group, point, x, y, ctx);
 769 }
 770
 771 #ifndef OPENSSL_NO_EC2M
 772 int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group,
 773                                          const EC_POINT *point, BIGNUM *x,
 774                                          BIGNUM *y, BN_CTX *ctx)
 775 {
 776     if (group->meth->point_get_affine_coordinates == 0) {
 777         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES_GF2M,
 778               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 779         return 0;
 780     }
 781     if (!ec_point_is_compat(point, group)) {
 782         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES_GF2M,
 783               EC_R_INCOMPATIBLE_OBJECTS);
 784         return 0;
 785     }
 786     return group->meth->point_get_affine_coordinates(group, point, x, y, ctx);
 787 }
 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     if (group->meth->mul == 0)
 923         /* use default */
 924         return ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
 925
 926     return group->meth->mul(group, r, scalar, num, points, scalars, ctx);
 927 }
 928
 929 int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
 930                  const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx)
 931 {
 932     /* just a convenient interface to EC_POINTs_mul() */
 933
 934     const EC_POINT *points[1];
 935     const BIGNUM *scalars[1];
 936
 937     points[0] = point;
 938     scalars[0] = p_scalar;
 939
 940     return EC_POINTs_mul(group, r, g_scalar,
 941                          (point != NULL
 942                           && p_scalar != NULL), points, scalars, ctx);
 943 }
 944
 945 int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
 946 {
 947     if (group->meth->mul == 0)
 948         /* use default */
 949         return ec_wNAF_precompute_mult(group, ctx);
 950
 951     if (group->meth->precompute_mult != 0)
 952         return group->meth->precompute_mult(group, ctx);
 953     else
 954         return 1;               /* nothing to do, so report success */
 955 }
 956
 957 int EC_GROUP_have_precompute_mult(const EC_GROUP *group)
 958 {
 959     if (group->meth->mul == 0)
 960         /* use default */
 961         return ec_wNAF_have_precompute_mult(group);
 962
 963     if (group->meth->have_precompute_mult != 0)
 964         return group->meth->have_precompute_mult(group);
 965     else
 966         return 0;               /* cannot tell whether precomputation has
 967                                  * been performed */
 968 }
 969
 970 /*
 971  * ec_precompute_mont_data sets |group->mont_data| from |group->order| and
 972  * returns one on success. On error it returns zero.
 973  */
 974 static int ec_precompute_mont_data(EC_GROUP *group)
 975 {
 976     BN_CTX *ctx = BN_CTX_new();
 977     int ret = 0;
 978
 979     BN_MONT_CTX_free(group->mont_data);
 980     group->mont_data = NULL;
 981
 982     if (ctx == NULL)
 983         goto err;
 984
 985     group->mont_data = BN_MONT_CTX_new();
 986     if (group->mont_data == NULL)
 987         goto err;
 988
 989     if (!BN_MONT_CTX_set(group->mont_data, group->order, ctx)) {
 990         BN_MONT_CTX_free(group->mont_data);
 991         group->mont_data = NULL;
 992         goto err;
 993     }
 994
 995     ret = 1;
 996
 997  err:
 998
 999     BN_CTX_free(ctx);
1000     return ret;
1001 }
1002
1003 int EC_KEY_set_ex_data(EC_KEY *key, int idx, void *arg)
1004 {
1005     return CRYPTO_set_ex_data(&key->ex_data, idx, arg);
1006 }
1007
1008 void *EC_KEY_get_ex_data(const EC_KEY *key, int idx)
1009 {
1010     return CRYPTO_get_ex_data(&key->ex_data, idx);
1011 }
1012
1013 int ec_group_simple_order_bits(const EC_GROUP *group)
1014 {
1015     if (group->order == NULL)
1016         return 0;
1017     return BN_num_bits(group->order);
1018 }
1019
1020 static int ec_field_inverse_mod_ord(const EC_GROUP *group, BIGNUM *r,
1021                                     BIGNUM *x, BN_CTX *ctx)
1022 {
1023     BIGNUM *e = NULL;
1024     BN_CTX *new_ctx = NULL;
1025     int ret = 0;
1026
1027     if (ctx == NULL && (ctx = new_ctx = BN_CTX_secure_new()) == NULL)
1028         return 0;
1029
1030     BN_CTX_start(ctx);
1031     if ((e = BN_CTX_get(ctx)) == NULL)
1032         goto err;
1033
1034     /* Check if optimized inverse is implemented */
1035     if (group->mont_data != NULL) {
1036         /*-
1037          * We want inverse in constant time, therefore we utilize the fact
1038          * order must be prime and use Fermats Little Theorem instead.
1039          */
1040         if (!BN_set_word(e, 2))
1041             goto err;
1042         if (!BN_sub(e, group->order, e))
1043             goto err;
1044         /*-
1045          * Exponent e is public.
1046          * No need for scatter-gather or BN_FLG_CONSTTIME.
1047          */
1048         if (!BN_mod_exp_mont(r, x, e, group->order, ctx, group->mont_data))
1049             goto err;
1050         /* Inverse of zero doesn't exist. Let the fallback catch it. */
1051         ret = (BN_is_zero(r)) ? 0 : 1;
1052     }
1053
1054     /* Fallback to classic inverse */
1055     if (ret == 0) {
1056         if (!BN_mod_inverse(r, x, group->order, ctx))
1057             goto err;
1058         ret = 1;
1059     }
1060
1061  err:
1062     if (ctx != NULL)
1063         BN_CTX_end(ctx);
1064     BN_CTX_free(new_ctx);
1065     return ret;
1066 }
1067
1068 int EC_GROUP_do_inverse_ord(const EC_GROUP *group, BIGNUM *res,
1069                             BIGNUM *x, BN_CTX *ctx)
1070 {
1071     if (group->meth->field_inverse_mod_ord != NULL)
1072         return group->meth->field_inverse_mod_ord(group, res, x, ctx);
1073     else
1074         return ec_field_inverse_mod_ord(group, res, x, ctx);
1075 }
1076
1077 /*-
1078  * Coordinate blinding for EC_POINT.
1079  *
1080  * The underlying EC_METHOD can optionally implement this function:
1081  * underlying implementations should return 0 on errors, or 1 on
1082  * success.
1083  *
1084  * This wrapper returns 1 in case the underlying EC_METHOD does not
1085  * support coordinate blinding.
1086  */
1087 int ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx)
1088 {
1089     if (group->meth->blind_coordinates == NULL)
1090         return 1; /* ignore if not implemented */
1091
1092     return group->meth->blind_coordinates(group, p, ctx);
1093 }