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_ex(OPENSSL_CTX *libctx, const EC_METHOD *meth)
  21 {
  22     EC_GROUP *ret;
  23
  24     if (meth == NULL) {
  25         ECerr(EC_F_EC_GROUP_NEW_EX, EC_R_SLOT_FULL);
  26         return NULL;
  27     }
  28     if (meth->group_init == 0) {
  29         ECerr(EC_F_EC_GROUP_NEW_EX, 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_EX, ERR_R_MALLOC_FAILURE);
  36         return NULL;
  37     }
  38
  39     ret->libctx = libctx;
  40     ret->meth = meth;
  41     if ((ret->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) {
  42         ret->order = BN_new();
  43         if (ret->order == NULL)
  44             goto err;
  45         ret->cofactor = BN_new();
  46         if (ret->cofactor == NULL)
  47             goto err;
  48     }
  49     ret->asn1_flag = OPENSSL_EC_NAMED_CURVE;
  50     ret->asn1_form = POINT_CONVERSION_UNCOMPRESSED;
  51     if (!meth->group_init(ret))
  52         goto err;
  53     return ret;
  54
  55  err:
  56     BN_free(ret->order);
  57     BN_free(ret->cofactor);
  58     OPENSSL_free(ret);
  59     return NULL;
  60 }
  61
  62 #ifndef FIPS_MODE
  63 EC_GROUP *EC_GROUP_new(const EC_METHOD *meth)
  64 {
  65     return EC_GROUP_new_ex(NULL, meth);
  66 }
  67 #endif
  68
  69 void EC_pre_comp_free(EC_GROUP *group)
  70 {
  71     switch (group->pre_comp_type) {
  72     case PCT_none:
  73         break;
  74     case PCT_nistz256:
  75 #ifdef ECP_NISTZ256_ASM
  76         EC_nistz256_pre_comp_free(group->pre_comp.nistz256);
  77 #endif
  78         break;
  79 #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
  80     case PCT_nistp224:
  81         EC_nistp224_pre_comp_free(group->pre_comp.nistp224);
  82         break;
  83     case PCT_nistp256:
  84         EC_nistp256_pre_comp_free(group->pre_comp.nistp256);
  85         break;
  86     case PCT_nistp521:
  87         EC_nistp521_pre_comp_free(group->pre_comp.nistp521);
  88         break;
  89 #else
  90     case PCT_nistp224:
  91     case PCT_nistp256:
  92     case PCT_nistp521:
  93         break;
  94 #endif
  95     case PCT_ec:
  96         EC_ec_pre_comp_free(group->pre_comp.ec);
  97         break;
  98     }
  99     group->pre_comp.ec = NULL;
 100 }
 101
 102 void EC_GROUP_free(EC_GROUP *group)
 103 {
 104     if (!group)
 105         return;
 106
 107     if (group->meth->group_finish != 0)
 108         group->meth->group_finish(group);
 109
 110     EC_pre_comp_free(group);
 111     BN_MONT_CTX_free(group->mont_data);
 112     EC_POINT_free(group->generator);
 113     BN_free(group->order);
 114     BN_free(group->cofactor);
 115     OPENSSL_free(group->seed);
 116     OPENSSL_free(group);
 117 }
 118
 119 void EC_GROUP_clear_free(EC_GROUP *group)
 120 {
 121     if (!group)
 122         return;
 123
 124     if (group->meth->group_clear_finish != 0)
 125         group->meth->group_clear_finish(group);
 126     else if (group->meth->group_finish != 0)
 127         group->meth->group_finish(group);
 128
 129     EC_pre_comp_free(group);
 130     BN_MONT_CTX_free(group->mont_data);
 131     EC_POINT_clear_free(group->generator);
 132     BN_clear_free(group->order);
 133     BN_clear_free(group->cofactor);
 134     OPENSSL_clear_free(group->seed, group->seed_len);
 135     OPENSSL_clear_free(group, sizeof(*group));
 136 }
 137
 138 int EC_GROUP_copy(EC_GROUP *dest, const EC_GROUP *src)
 139 {
 140     if (dest->meth->group_copy == 0) {
 141         ECerr(EC_F_EC_GROUP_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 142         return 0;
 143     }
 144     if (dest->meth != src->meth) {
 145         ECerr(EC_F_EC_GROUP_COPY, EC_R_INCOMPATIBLE_OBJECTS);
 146         return 0;
 147     }
 148     if (dest == src)
 149         return 1;
 150
 151     dest->libctx = src->libctx;
 152     dest->curve_name = src->curve_name;
 153
 154     /* Copy precomputed */
 155     dest->pre_comp_type = src->pre_comp_type;
 156     switch (src->pre_comp_type) {
 157     case PCT_none:
 158         dest->pre_comp.ec = NULL;
 159         break;
 160     case PCT_nistz256:
 161 #ifdef ECP_NISTZ256_ASM
 162         dest->pre_comp.nistz256 = EC_nistz256_pre_comp_dup(src->pre_comp.nistz256);
 163 #endif
 164         break;
 165 #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
 166     case PCT_nistp224:
 167         dest->pre_comp.nistp224 = EC_nistp224_pre_comp_dup(src->pre_comp.nistp224);
 168         break;
 169     case PCT_nistp256:
 170         dest->pre_comp.nistp256 = EC_nistp256_pre_comp_dup(src->pre_comp.nistp256);
 171         break;
 172     case PCT_nistp521:
 173         dest->pre_comp.nistp521 = EC_nistp521_pre_comp_dup(src->pre_comp.nistp521);
 174         break;
 175 #else
 176     case PCT_nistp224:
 177     case PCT_nistp256:
 178     case PCT_nistp521:
 179         break;
 180 #endif
 181     case PCT_ec:
 182         dest->pre_comp.ec = EC_ec_pre_comp_dup(src->pre_comp.ec);
 183         break;
 184     }
 185
 186     if (src->mont_data != NULL) {
 187         if (dest->mont_data == NULL) {
 188             dest->mont_data = BN_MONT_CTX_new();
 189             if (dest->mont_data == NULL)
 190                 return 0;
 191         }
 192         if (!BN_MONT_CTX_copy(dest->mont_data, src->mont_data))
 193             return 0;
 194     } else {
 195         /* src->generator == NULL */
 196         BN_MONT_CTX_free(dest->mont_data);
 197         dest->mont_data = NULL;
 198     }
 199
 200     if (src->generator != NULL) {
 201         if (dest->generator == NULL) {
 202             dest->generator = EC_POINT_new(dest);
 203             if (dest->generator == NULL)
 204                 return 0;
 205         }
 206         if (!EC_POINT_copy(dest->generator, src->generator))
 207             return 0;
 208     } else {
 209         /* src->generator == NULL */
 210         EC_POINT_clear_free(dest->generator);
 211         dest->generator = NULL;
 212     }
 213
 214     if ((src->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) {
 215         if (!BN_copy(dest->order, src->order))
 216             return 0;
 217         if (!BN_copy(dest->cofactor, src->cofactor))
 218             return 0;
 219     }
 220
 221     dest->asn1_flag = src->asn1_flag;
 222     dest->asn1_form = src->asn1_form;
 223
 224     if (src->seed) {
 225         OPENSSL_free(dest->seed);
 226         if ((dest->seed = OPENSSL_malloc(src->seed_len)) == NULL) {
 227             ECerr(EC_F_EC_GROUP_COPY, ERR_R_MALLOC_FAILURE);
 228             return 0;
 229         }
 230         if (!memcpy(dest->seed, src->seed, src->seed_len))
 231             return 0;
 232         dest->seed_len = src->seed_len;
 233     } else {
 234         OPENSSL_free(dest->seed);
 235         dest->seed = NULL;
 236         dest->seed_len = 0;
 237     }
 238
 239     return dest->meth->group_copy(dest, src);
 240 }
 241
 242 EC_GROUP *EC_GROUP_dup(const EC_GROUP *a)
 243 {
 244     EC_GROUP *t = NULL;
 245     int ok = 0;
 246
 247     if (a == NULL)
 248         return NULL;
 249
 250     if ((t = EC_GROUP_new_ex(a->libctx, a->meth)) == NULL)
 251         return NULL;
 252     if (!EC_GROUP_copy(t, a))
 253         goto err;
 254
 255     ok = 1;
 256
 257  err:
 258     if (!ok) {
 259         EC_GROUP_free(t);
 260         return NULL;
 261     }
 262         return t;
 263 }
 264
 265 const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group)
 266 {
 267     return group->meth;
 268 }
 269
 270 int EC_METHOD_get_field_type(const EC_METHOD *meth)
 271 {
 272     return meth->field_type;
 273 }
 274
 275 static int ec_precompute_mont_data(EC_GROUP *);
 276
 277 int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator,
 278                            const BIGNUM *order, const BIGNUM *cofactor)
 279 {
 280     if (generator == NULL) {
 281         ECerr(EC_F_EC_GROUP_SET_GENERATOR, ERR_R_PASSED_NULL_PARAMETER);
 282         return 0;
 283     }
 284
 285     if (group->generator == NULL) {
 286         group->generator = EC_POINT_new(group);
 287         if (group->generator == NULL)
 288             return 0;
 289     }
 290     if (!EC_POINT_copy(group->generator, generator))
 291         return 0;
 292
 293     if (order != NULL) {
 294         if (!BN_copy(group->order, order))
 295             return 0;
 296     } else {
 297         BN_zero(group->order);
 298     }
 299
 300     /* The cofactor is an optional field, so it should be able to be NULL. */
 301     if (cofactor != NULL) {
 302         if (!BN_copy(group->cofactor, cofactor))
 303             return 0;
 304     } else {
 305         BN_zero(group->cofactor);
 306     }
 307     /*
 308      * Some groups have an order with
 309      * factors of two, which makes the Montgomery setup fail.
 310      * |group->mont_data| will be NULL in this case.
 311      */
 312     if (BN_is_odd(group->order)) {
 313         return ec_precompute_mont_data(group);
 314     }
 315
 316     BN_MONT_CTX_free(group->mont_data);
 317     group->mont_data = NULL;
 318     return 1;
 319 }
 320
 321 const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group)
 322 {
 323     return group->generator;
 324 }
 325
 326 BN_MONT_CTX *EC_GROUP_get_mont_data(const EC_GROUP *group)
 327 {
 328     return group->mont_data;
 329 }
 330
 331 int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, BN_CTX *ctx)
 332 {
 333     if (group->order == NULL)
 334         return 0;
 335     if (!BN_copy(order, group->order))
 336         return 0;
 337
 338     return !BN_is_zero(order);
 339 }
 340
 341 const BIGNUM *EC_GROUP_get0_order(const EC_GROUP *group)
 342 {
 343     return group->order;
 344 }
 345
 346 int EC_GROUP_order_bits(const EC_GROUP *group)
 347 {
 348     return group->meth->group_order_bits(group);
 349 }
 350
 351 int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor,
 352                           BN_CTX *ctx)
 353 {
 354
 355     if (group->cofactor == NULL)
 356         return 0;
 357     if (!BN_copy(cofactor, group->cofactor))
 358         return 0;
 359
 360     return !BN_is_zero(group->cofactor);
 361 }
 362
 363 const BIGNUM *EC_GROUP_get0_cofactor(const EC_GROUP *group)
 364 {
 365     return group->cofactor;
 366 }
 367
 368 void EC_GROUP_set_curve_name(EC_GROUP *group, int nid)
 369 {
 370     group->curve_name = nid;
 371 }
 372
 373 int EC_GROUP_get_curve_name(const EC_GROUP *group)
 374 {
 375     return group->curve_name;
 376 }
 377
 378 const BIGNUM *EC_GROUP_get0_field(const EC_GROUP *group)
 379 {
 380     return group->field;
 381 }
 382
 383 void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag)
 384 {
 385     group->asn1_flag = flag;
 386 }
 387
 388 int EC_GROUP_get_asn1_flag(const EC_GROUP *group)
 389 {
 390     return group->asn1_flag;
 391 }
 392
 393 void EC_GROUP_set_point_conversion_form(EC_GROUP *group,
 394                                         point_conversion_form_t form)
 395 {
 396     group->asn1_form = form;
 397 }
 398
 399 point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP
 400                                                            *group)
 401 {
 402     return group->asn1_form;
 403 }
 404
 405 size_t EC_GROUP_set_seed(EC_GROUP *group, const unsigned char *p, size_t len)
 406 {
 407     OPENSSL_free(group->seed);
 408     group->seed = NULL;
 409     group->seed_len = 0;
 410
 411     if (!len || !p)
 412         return 1;
 413
 414     if ((group->seed = OPENSSL_malloc(len)) == NULL) {
 415         ECerr(EC_F_EC_GROUP_SET_SEED, ERR_R_MALLOC_FAILURE);
 416         return 0;
 417     }
 418     memcpy(group->seed, p, len);
 419     group->seed_len = len;
 420
 421     return len;
 422 }
 423
 424 unsigned char *EC_GROUP_get0_seed(const EC_GROUP *group)
 425 {
 426     return group->seed;
 427 }
 428
 429 size_t EC_GROUP_get_seed_len(const EC_GROUP *group)
 430 {
 431     return group->seed_len;
 432 }
 433
 434 int EC_GROUP_set_curve(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
 435                        const BIGNUM *b, BN_CTX *ctx)
 436 {
 437     if (group->meth->group_set_curve == 0) {
 438         ECerr(EC_F_EC_GROUP_SET_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 439         return 0;
 440     }
 441     return group->meth->group_set_curve(group, p, a, b, ctx);
 442 }
 443
 444 int EC_GROUP_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b,
 445                        BN_CTX *ctx)
 446 {
 447     if (group->meth->group_get_curve == NULL) {
 448         ECerr(EC_F_EC_GROUP_GET_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 449         return 0;
 450     }
 451     return group->meth->group_get_curve(group, p, a, b, ctx);
 452 }
 453
 454 #if !OPENSSL_API_3
 455 int EC_GROUP_set_curve_GFp(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
 456                            const BIGNUM *b, BN_CTX *ctx)
 457 {
 458     return EC_GROUP_set_curve(group, p, a, b, ctx);
 459 }
 460
 461 int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
 462                            BIGNUM *b, BN_CTX *ctx)
 463 {
 464     return EC_GROUP_get_curve(group, p, a, b, ctx);
 465 }
 466
 467 # ifndef OPENSSL_NO_EC2M
 468 int EC_GROUP_set_curve_GF2m(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
 469                             const BIGNUM *b, BN_CTX *ctx)
 470 {
 471     return EC_GROUP_set_curve(group, p, a, b, ctx);
 472 }
 473
 474 int EC_GROUP_get_curve_GF2m(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
 475                             BIGNUM *b, BN_CTX *ctx)
 476 {
 477     return EC_GROUP_get_curve(group, p, a, b, ctx);
 478 }
 479 # endif
 480 #endif
 481
 482 int EC_GROUP_get_degree(const EC_GROUP *group)
 483 {
 484     if (group->meth->group_get_degree == 0) {
 485         ECerr(EC_F_EC_GROUP_GET_DEGREE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 486         return 0;
 487     }
 488     return group->meth->group_get_degree(group);
 489 }
 490
 491 int EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
 492 {
 493     if (group->meth->group_check_discriminant == 0) {
 494         ECerr(EC_F_EC_GROUP_CHECK_DISCRIMINANT,
 495               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 496         return 0;
 497     }
 498     return group->meth->group_check_discriminant(group, ctx);
 499 }
 500
 501 int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ctx)
 502 {
 503     int r = 0;
 504     BIGNUM *a1, *a2, *a3, *b1, *b2, *b3;
 505 #ifndef FIPS_MODE
 506     BN_CTX *ctx_new = NULL;
 507
 508     if (ctx == NULL)
 509         ctx_new = ctx = BN_CTX_new();
 510 #endif
 511     if (ctx == NULL)
 512         return -1;
 513
 514     /* compare the field types */
 515     if (EC_METHOD_get_field_type(EC_GROUP_method_of(a)) !=
 516         EC_METHOD_get_field_type(EC_GROUP_method_of(b)))
 517         return 1;
 518     /* compare the curve name (if present in both) */
 519     if (EC_GROUP_get_curve_name(a) && EC_GROUP_get_curve_name(b) &&
 520         EC_GROUP_get_curve_name(a) != EC_GROUP_get_curve_name(b))
 521         return 1;
 522     if (a->meth->flags & EC_FLAGS_CUSTOM_CURVE)
 523         return 0;
 524
 525     BN_CTX_start(ctx);
 526     a1 = BN_CTX_get(ctx);
 527     a2 = BN_CTX_get(ctx);
 528     a3 = BN_CTX_get(ctx);
 529     b1 = BN_CTX_get(ctx);
 530     b2 = BN_CTX_get(ctx);
 531     b3 = BN_CTX_get(ctx);
 532     if (b3 == NULL) {
 533         BN_CTX_end(ctx);
 534 #ifndef FIPS_MODE
 535         BN_CTX_free(ctx_new);
 536 #endif
 537         return -1;
 538     }
 539
 540     /*
 541      * XXX This approach assumes that the external representation of curves
 542      * over the same field type is the same.
 543      */
 544     if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) ||
 545         !b->meth->group_get_curve(b, b1, b2, b3, ctx))
 546         r = 1;
 547
 548     /* return 1 if the curve parameters are different */
 549     if (r || BN_cmp(a1, b1) != 0 || BN_cmp(a2, b2) != 0 || BN_cmp(a3, b3) != 0)
 550         r = 1;
 551
 552     /* XXX EC_POINT_cmp() assumes that the methods are equal */
 553     /* return 1 if the generators are different */
 554     if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a),
 555                           EC_GROUP_get0_generator(b), ctx) != 0)
 556         r = 1;
 557
 558     if (!r) {
 559         const BIGNUM *ao, *bo, *ac, *bc;
 560         /* compare the orders */
 561         ao = EC_GROUP_get0_order(a);
 562         bo = EC_GROUP_get0_order(b);
 563         if (ao == NULL || bo == NULL) {
 564             /* return an error if either order is NULL */
 565             r = -1;
 566             goto end;
 567         }
 568         if (BN_cmp(ao, bo) != 0) {
 569             /* return 1 if orders are different */
 570             r = 1;
 571             goto end;
 572         }
 573         /*
 574          * It gets here if the curve parameters and generator matched.
 575          * Now check the optional cofactors (if both are present).
 576          */
 577         ac = EC_GROUP_get0_cofactor(a);
 578         bc = EC_GROUP_get0_cofactor(b);
 579         /* Returns 1 (mismatch) if both cofactors are specified and different */
 580         if (!BN_is_zero(ac) && !BN_is_zero(bc) && BN_cmp(ac, bc) != 0)
 581             r = 1;
 582         /* Returns 0 if the parameters matched */
 583     }
 584 end:
 585     BN_CTX_end(ctx);
 586 #ifndef FIPS_MODE
 587     BN_CTX_free(ctx_new);
 588 #endif
 589     return r;
 590 }
 591
 592 /* functions for EC_POINT objects */
 593
 594 EC_POINT *EC_POINT_new(const EC_GROUP *group)
 595 {
 596     EC_POINT *ret;
 597
 598     if (group == NULL) {
 599         ECerr(EC_F_EC_POINT_NEW, ERR_R_PASSED_NULL_PARAMETER);
 600         return NULL;
 601     }
 602     if (group->meth->point_init == NULL) {
 603         ECerr(EC_F_EC_POINT_NEW, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 604         return NULL;
 605     }
 606
 607     ret = OPENSSL_zalloc(sizeof(*ret));
 608     if (ret == NULL) {
 609         ECerr(EC_F_EC_POINT_NEW, ERR_R_MALLOC_FAILURE);
 610         return NULL;
 611     }
 612
 613     ret->meth = group->meth;
 614     ret->curve_name = group->curve_name;
 615
 616     if (!ret->meth->point_init(ret)) {
 617         OPENSSL_free(ret);
 618         return NULL;
 619     }
 620
 621     return ret;
 622 }
 623
 624 void EC_POINT_free(EC_POINT *point)
 625 {
 626     if (!point)
 627         return;
 628
 629     if (point->meth->point_finish != 0)
 630         point->meth->point_finish(point);
 631     OPENSSL_free(point);
 632 }
 633
 634 void EC_POINT_clear_free(EC_POINT *point)
 635 {
 636     if (!point)
 637         return;
 638
 639     if (point->meth->point_clear_finish != 0)
 640         point->meth->point_clear_finish(point);
 641     else if (point->meth->point_finish != 0)
 642         point->meth->point_finish(point);
 643     OPENSSL_clear_free(point, sizeof(*point));
 644 }
 645
 646 int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src)
 647 {
 648     if (dest->meth->point_copy == 0) {
 649         ECerr(EC_F_EC_POINT_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 650         return 0;
 651     }
 652     if (dest->meth != src->meth
 653             || (dest->curve_name != src->curve_name
 654                  && dest->curve_name != 0
 655                  && src->curve_name != 0)) {
 656         ECerr(EC_F_EC_POINT_COPY, EC_R_INCOMPATIBLE_OBJECTS);
 657         return 0;
 658     }
 659     if (dest == src)
 660         return 1;
 661     return dest->meth->point_copy(dest, src);
 662 }
 663
 664 EC_POINT *EC_POINT_dup(const EC_POINT *a, const EC_GROUP *group)
 665 {
 666     EC_POINT *t;
 667     int r;
 668
 669     if (a == NULL)
 670         return NULL;
 671
 672     t = EC_POINT_new(group);
 673     if (t == NULL)
 674         return NULL;
 675     r = EC_POINT_copy(t, a);
 676     if (!r) {
 677         EC_POINT_free(t);
 678         return NULL;
 679     }
 680     return t;
 681 }
 682
 683 const EC_METHOD *EC_POINT_method_of(const EC_POINT *point)
 684 {
 685     return point->meth;
 686 }
 687
 688 int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
 689 {
 690     if (group->meth->point_set_to_infinity == 0) {
 691         ECerr(EC_F_EC_POINT_SET_TO_INFINITY,
 692               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 693         return 0;
 694     }
 695     if (group->meth != point->meth) {
 696         ECerr(EC_F_EC_POINT_SET_TO_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
 697         return 0;
 698     }
 699     return group->meth->point_set_to_infinity(group, point);
 700 }
 701
 702 int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
 703                                              EC_POINT *point, const BIGNUM *x,
 704                                              const BIGNUM *y, const BIGNUM *z,
 705                                              BN_CTX *ctx)
 706 {
 707     if (group->meth->point_set_Jprojective_coordinates_GFp == 0) {
 708         ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP,
 709               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 710         return 0;
 711     }
 712     if (!ec_point_is_compat(point, group)) {
 713         ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP,
 714               EC_R_INCOMPATIBLE_OBJECTS);
 715         return 0;
 716     }
 717     return group->meth->point_set_Jprojective_coordinates_GFp(group, point, x,
 718                                                               y, z, ctx);
 719 }
 720
 721 int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
 722                                              const EC_POINT *point, BIGNUM *x,
 723                                              BIGNUM *y, BIGNUM *z,
 724                                              BN_CTX *ctx)
 725 {
 726     if (group->meth->point_get_Jprojective_coordinates_GFp == 0) {
 727         ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP,
 728               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 729         return 0;
 730     }
 731     if (!ec_point_is_compat(point, group)) {
 732         ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP,
 733               EC_R_INCOMPATIBLE_OBJECTS);
 734         return 0;
 735     }
 736     return group->meth->point_get_Jprojective_coordinates_GFp(group, point, x,
 737                                                               y, z, ctx);
 738 }
 739
 740 int EC_POINT_set_affine_coordinates(const EC_GROUP *group, EC_POINT *point,
 741                                     const BIGNUM *x, const BIGNUM *y,
 742                                     BN_CTX *ctx)
 743 {
 744     if (group->meth->point_set_affine_coordinates == NULL) {
 745         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES,
 746               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 747         return 0;
 748     }
 749     if (!ec_point_is_compat(point, group)) {
 750         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES, EC_R_INCOMPATIBLE_OBJECTS);
 751         return 0;
 752     }
 753     if (!group->meth->point_set_affine_coordinates(group, point, x, y, ctx))
 754         return 0;
 755
 756     if (EC_POINT_is_on_curve(group, point, ctx) <= 0) {
 757         ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES, EC_R_POINT_IS_NOT_ON_CURVE);
 758         return 0;
 759     }
 760     return 1;
 761 }
 762
 763 #if !OPENSSL_API_3
 764 int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group,
 765                                         EC_POINT *point, const BIGNUM *x,
 766                                         const BIGNUM *y, BN_CTX *ctx)
 767 {
 768     return EC_POINT_set_affine_coordinates(group, point, x, y, ctx);
 769 }
 770
 771 # ifndef OPENSSL_NO_EC2M
 772 int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group,
 773                                          EC_POINT *point, const BIGNUM *x,
 774                                          const BIGNUM *y, BN_CTX *ctx)
 775 {
 776     return EC_POINT_set_affine_coordinates(group, point, x, y, ctx);
 777 }
 778 # endif
 779 #endif
 780
 781 int EC_POINT_get_affine_coordinates(const EC_GROUP *group,
 782                                     const EC_POINT *point, BIGNUM *x, BIGNUM *y,
 783                                     BN_CTX *ctx)
 784 {
 785     if (group->meth->point_get_affine_coordinates == NULL) {
 786         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES,
 787               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 788         return 0;
 789     }
 790     if (!ec_point_is_compat(point, group)) {
 791         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES, EC_R_INCOMPATIBLE_OBJECTS);
 792         return 0;
 793     }
 794     if (EC_POINT_is_at_infinity(group, point)) {
 795         ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES, EC_R_POINT_AT_INFINITY);
 796         return 0;
 797     }
 798     return group->meth->point_get_affine_coordinates(group, point, x, y, ctx);
 799 }
 800
 801 #if !OPENSSL_API_3
 802 int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group,
 803                                         const EC_POINT *point, BIGNUM *x,
 804                                         BIGNUM *y, BN_CTX *ctx)
 805 {
 806     return EC_POINT_get_affine_coordinates(group, point, x, y, ctx);
 807 }
 808
 809 # ifndef OPENSSL_NO_EC2M
 810 int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group,
 811                                          const EC_POINT *point, BIGNUM *x,
 812                                          BIGNUM *y, BN_CTX *ctx)
 813 {
 814     return EC_POINT_get_affine_coordinates(group, point, x, y, ctx);
 815 }
 816 # endif
 817 #endif
 818
 819 int EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
 820                  const EC_POINT *b, BN_CTX *ctx)
 821 {
 822     if (group->meth->add == 0) {
 823         ECerr(EC_F_EC_POINT_ADD, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 824         return 0;
 825     }
 826     if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group)
 827         || !ec_point_is_compat(b, group)) {
 828         ECerr(EC_F_EC_POINT_ADD, EC_R_INCOMPATIBLE_OBJECTS);
 829         return 0;
 830     }
 831     return group->meth->add(group, r, a, b, ctx);
 832 }
 833
 834 int EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
 835                  BN_CTX *ctx)
 836 {
 837     if (group->meth->dbl == 0) {
 838         ECerr(EC_F_EC_POINT_DBL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 839         return 0;
 840     }
 841     if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group)) {
 842         ECerr(EC_F_EC_POINT_DBL, EC_R_INCOMPATIBLE_OBJECTS);
 843         return 0;
 844     }
 845     return group->meth->dbl(group, r, a, ctx);
 846 }
 847
 848 int EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx)
 849 {
 850     if (group->meth->invert == 0) {
 851         ECerr(EC_F_EC_POINT_INVERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 852         return 0;
 853     }
 854     if (!ec_point_is_compat(a, group)) {
 855         ECerr(EC_F_EC_POINT_INVERT, EC_R_INCOMPATIBLE_OBJECTS);
 856         return 0;
 857     }
 858     return group->meth->invert(group, a, ctx);
 859 }
 860
 861 int EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
 862 {
 863     if (group->meth->is_at_infinity == 0) {
 864         ECerr(EC_F_EC_POINT_IS_AT_INFINITY,
 865               ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 866         return 0;
 867     }
 868     if (!ec_point_is_compat(point, group)) {
 869         ECerr(EC_F_EC_POINT_IS_AT_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
 870         return 0;
 871     }
 872     return group->meth->is_at_infinity(group, point);
 873 }
 874
 875 /*
 876  * Check whether an EC_POINT is on the curve or not. Note that the return
 877  * value for this function should NOT be treated as a boolean. Return values:
 878  *  1: The point is on the curve
 879  *  0: The point is not on the curve
 880  * -1: An error occurred
 881  */
 882 int EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
 883                          BN_CTX *ctx)
 884 {
 885     if (group->meth->is_on_curve == 0) {
 886         ECerr(EC_F_EC_POINT_IS_ON_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 887         return 0;
 888     }
 889     if (!ec_point_is_compat(point, group)) {
 890         ECerr(EC_F_EC_POINT_IS_ON_CURVE, EC_R_INCOMPATIBLE_OBJECTS);
 891         return 0;
 892     }
 893     return group->meth->is_on_curve(group, point, ctx);
 894 }
 895
 896 int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b,
 897                  BN_CTX *ctx)
 898 {
 899     if (group->meth->point_cmp == 0) {
 900         ECerr(EC_F_EC_POINT_CMP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 901         return -1;
 902     }
 903     if (!ec_point_is_compat(a, group) || !ec_point_is_compat(b, group)) {
 904         ECerr(EC_F_EC_POINT_CMP, EC_R_INCOMPATIBLE_OBJECTS);
 905         return -1;
 906     }
 907     return group->meth->point_cmp(group, a, b, ctx);
 908 }
 909
 910 int EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
 911 {
 912     if (group->meth->make_affine == 0) {
 913         ECerr(EC_F_EC_POINT_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 914         return 0;
 915     }
 916     if (!ec_point_is_compat(point, group)) {
 917         ECerr(EC_F_EC_POINT_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
 918         return 0;
 919     }
 920     return group->meth->make_affine(group, point, ctx);
 921 }
 922
 923 int EC_POINTs_make_affine(const EC_GROUP *group, size_t num,
 924                           EC_POINT *points[], BN_CTX *ctx)
 925 {
 926     size_t i;
 927
 928     if (group->meth->points_make_affine == 0) {
 929         ECerr(EC_F_EC_POINTS_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
 930         return 0;
 931     }
 932     for (i = 0; i < num; i++) {
 933         if (!ec_point_is_compat(points[i], group)) {
 934             ECerr(EC_F_EC_POINTS_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
 935             return 0;
 936         }
 937     }
 938     return group->meth->points_make_affine(group, num, points, ctx);
 939 }
 940
 941 /*
 942  * Functions for point multiplication. If group->meth->mul is 0, we use the
 943  * wNAF-based implementations in ec_mult.c; otherwise we dispatch through
 944  * methods.
 945  */
 946
 947 int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
 948                   size_t num, const EC_POINT *points[],
 949                   const BIGNUM *scalars[], BN_CTX *ctx)
 950 {
 951     int ret = 0;
 952     size_t i = 0;
 953 #ifndef FIPS_MODE
 954     BN_CTX *new_ctx = NULL;
 955
 956     if (ctx == NULL)
 957         ctx = new_ctx = BN_CTX_secure_new();
 958 #endif
 959     if (ctx == NULL) {
 960         ECerr(EC_F_EC_POINTS_MUL, ERR_R_INTERNAL_ERROR);
 961         return 0;
 962     }
 963
 964     if ((scalar == NULL) && (num == 0)) {
 965         return EC_POINT_set_to_infinity(group, r);
 966     }
 967
 968     if (!ec_point_is_compat(r, group)) {
 969         ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
 970         return 0;
 971     }
 972     for (i = 0; i < num; i++) {
 973         if (!ec_point_is_compat(points[i], group)) {
 974             ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
 975             return 0;
 976         }
 977     }
 978
 979     if (group->meth->mul != NULL)
 980         ret = group->meth->mul(group, r, scalar, num, points, scalars, ctx);
 981     else
 982         /* use default */
 983         ret = ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
 984
 985 #ifndef FIPS_MODE
 986     BN_CTX_free(new_ctx);
 987 #endif
 988     return ret;
 989 }
 990
 991 int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
 992                  const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx)
 993 {
 994     /* just a convenient interface to EC_POINTs_mul() */
 995
 996     const EC_POINT *points[1];
 997     const BIGNUM *scalars[1];
 998
 999     points[0] = point;
1000     scalars[0] = p_scalar;
1001
1002     return EC_POINTs_mul(group, r, g_scalar,
1003                          (point != NULL
1004                           && p_scalar != NULL), points, scalars, ctx);
1005 }
1006
1007 int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
1008 {
1009     if (group->meth->mul == 0)
1010         /* use default */
1011         return ec_wNAF_precompute_mult(group, ctx);
1012
1013     if (group->meth->precompute_mult != 0)
1014         return group->meth->precompute_mult(group, ctx);
1015     else
1016         return 1;               /* nothing to do, so report success */
1017 }
1018
1019 int EC_GROUP_have_precompute_mult(const EC_GROUP *group)
1020 {
1021     if (group->meth->mul == 0)
1022         /* use default */
1023         return ec_wNAF_have_precompute_mult(group);
1024
1025     if (group->meth->have_precompute_mult != 0)
1026         return group->meth->have_precompute_mult(group);
1027     else
1028         return 0;               /* cannot tell whether precomputation has
1029                                  * been performed */
1030 }
1031
1032 /*
1033  * ec_precompute_mont_data sets |group->mont_data| from |group->order| and
1034  * returns one on success. On error it returns zero.
1035  */
1036 static int ec_precompute_mont_data(EC_GROUP *group)
1037 {
1038     BN_CTX *ctx = BN_CTX_new_ex(group->libctx);
1039     int ret = 0;
1040
1041     BN_MONT_CTX_free(group->mont_data);
1042     group->mont_data = NULL;
1043
1044     if (ctx == NULL)
1045         goto err;
1046
1047     group->mont_data = BN_MONT_CTX_new();
1048     if (group->mont_data == NULL)
1049         goto err;
1050
1051     if (!BN_MONT_CTX_set(group->mont_data, group->order, ctx)) {
1052         BN_MONT_CTX_free(group->mont_data);
1053         group->mont_data = NULL;
1054         goto err;
1055     }
1056
1057     ret = 1;
1058
1059  err:
1060
1061     BN_CTX_free(ctx);
1062     return ret;
1063 }
1064
1065 #ifndef FIPS_MODE
1066 int EC_KEY_set_ex_data(EC_KEY *key, int idx, void *arg)
1067 {
1068     return CRYPTO_set_ex_data(&key->ex_data, idx, arg);
1069 }
1070
1071 void *EC_KEY_get_ex_data(const EC_KEY *key, int idx)
1072 {
1073     return CRYPTO_get_ex_data(&key->ex_data, idx);
1074 }
1075 #endif
1076
1077 int ec_group_simple_order_bits(const EC_GROUP *group)
1078 {
1079     if (group->order == NULL)
1080         return 0;
1081     return BN_num_bits(group->order);
1082 }
1083
1084 static int ec_field_inverse_mod_ord(const EC_GROUP *group, BIGNUM *r,
1085                                     const BIGNUM *x, BN_CTX *ctx)
1086 {
1087     BIGNUM *e = NULL;
1088     int ret = 0;
1089 #ifndef FIPS_MODE
1090     BN_CTX *new_ctx = NULL;
1091
1092     if (ctx == NULL)
1093         ctx = new_ctx = BN_CTX_secure_new();
1094 #endif
1095     if (ctx == NULL)
1096         return 0;
1097
1098     if (group->mont_data == NULL)
1099         goto err;
1100
1101     BN_CTX_start(ctx);
1102     if ((e = BN_CTX_get(ctx)) == NULL)
1103         goto err;
1104
1105     /*-
1106      * We want inverse in constant time, therefore we utilize the fact
1107      * order must be prime and use Fermats Little Theorem instead.
1108      */
1109     if (!BN_set_word(e, 2))
1110         goto err;
1111     if (!BN_sub(e, group->order, e))
1112         goto err;
1113     /*-
1114      * Exponent e is public.
1115      * No need for scatter-gather or BN_FLG_CONSTTIME.
1116      */
1117     if (!BN_mod_exp_mont(r, x, e, group->order, ctx, group->mont_data))
1118         goto err;
1119
1120     ret = 1;
1121
1122  err:
1123     BN_CTX_end(ctx);
1124 #ifndef FIPS_MODE
1125     BN_CTX_free(new_ctx);
1126 #endif
1127     return ret;
1128 }
1129
1130 /*-
1131  * Default behavior, if group->meth->field_inverse_mod_ord is NULL:
1132  * - When group->order is even, this function returns an error.
1133  * - When group->order is otherwise composite, the correctness
1134  *   of the output is not guaranteed.
1135  * - When x is outside the range [1, group->order), the correctness
1136  *   of the output is not guaranteed.
1137  * - Otherwise, this function returns the multiplicative inverse in the
1138  *   range [1, group->order).
1139  *
1140  * EC_METHODs must implement their own field_inverse_mod_ord for
1141  * other functionality.
1142  */
1143 int ec_group_do_inverse_ord(const EC_GROUP *group, BIGNUM *res,
1144                             const BIGNUM *x, BN_CTX *ctx)
1145 {
1146     if (group->meth->field_inverse_mod_ord != NULL)
1147         return group->meth->field_inverse_mod_ord(group, res, x, ctx);
1148     else
1149         return ec_field_inverse_mod_ord(group, res, x, ctx);
1150 }
1151
1152 /*-
1153  * Coordinate blinding for EC_POINT.
1154  *
1155  * The underlying EC_METHOD can optionally implement this function:
1156  * underlying implementations should return 0 on errors, or 1 on
1157  * success.
1158  *
1159  * This wrapper returns 1 in case the underlying EC_METHOD does not
1160  * support coordinate blinding.
1161  */
1162 int ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx)
1163 {
1164     if (group->meth->blind_coordinates == NULL)
1165         return 1; /* ignore if not implemented */
1166
1167     return group->meth->blind_coordinates(group, p, ctx);
1168 }