1 /* 2 * Copyright 2001-2022 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 /* 12 * EC_GROUP low level APIs are deprecated for public use, but still ok for 13 * internal use. 14 */ 15 #include "internal/deprecated.h" 16 17 #include <string.h> 18 #include <openssl/params.h> 19 #include <openssl/core_names.h> 20 #include <openssl/err.h> 21 #include <openssl/opensslv.h> 22 #include "crypto/ec.h" 23 #include "internal/nelem.h" 24 #include "ec_local.h" 25 26 /* functions for EC_GROUP objects */ 27 28 EC_GROUP *ossl_ec_group_new_ex(OSSL_LIB_CTX *libctx, const char *propq, 29 const EC_METHOD *meth) 30 { 31 EC_GROUP *ret; 32 33 if (meth == NULL) { 34 ERR_raise(ERR_LIB_EC, EC_R_SLOT_FULL); 35 return NULL; 36 } 37 if (meth->group_init == 0) { 38 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 39 return NULL; 40 } 41 42 ret = OPENSSL_zalloc(sizeof(*ret)); 43 if (ret == NULL) { 44 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE); 45 return NULL; 46 } 47 48 ret->libctx = libctx; 49 if (propq != NULL) { 50 ret->propq = OPENSSL_strdup(propq); 51 if (ret->propq == NULL) { 52 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE); 53 goto err; 54 } 55 } 56 ret->meth = meth; 57 if ((ret->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) { 58 ret->order = BN_new(); 59 if (ret->order == NULL) 60 goto err; 61 ret->cofactor = BN_new(); 62 if (ret->cofactor == NULL) 63 goto err; 64 } 65 ret->asn1_flag = OPENSSL_EC_EXPLICIT_CURVE; 66 ret->asn1_form = POINT_CONVERSION_UNCOMPRESSED; 67 if (!meth->group_init(ret)) 68 goto err; 69 return ret; 70 71 err: 72 BN_free(ret->order); 73 BN_free(ret->cofactor); 74 OPENSSL_free(ret->propq); 75 OPENSSL_free(ret); 76 return NULL; 77 } 78 79 #ifndef OPENSSL_NO_DEPRECATED_3_0 80 # ifndef FIPS_MODULE 81 EC_GROUP *EC_GROUP_new(const EC_METHOD *meth) 82 { 83 return ossl_ec_group_new_ex(NULL, NULL, meth); 84 } 85 # endif 86 #endif 87 88 void EC_pre_comp_free(EC_GROUP *group) 89 { 90 switch (group->pre_comp_type) { 91 case PCT_none: 92 break; 93 case PCT_nistz256: 94 #ifdef ECP_NISTZ256_ASM 95 EC_nistz256_pre_comp_free(group->pre_comp.nistz256); 96 #endif 97 break; 98 #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128 99 case PCT_nistp224: 100 EC_nistp224_pre_comp_free(group->pre_comp.nistp224); 101 break; 102 case PCT_nistp256: 103 EC_nistp256_pre_comp_free(group->pre_comp.nistp256); 104 break; 105 case PCT_nistp521: 106 EC_nistp521_pre_comp_free(group->pre_comp.nistp521); 107 break; 108 #else 109 case PCT_nistp224: 110 case PCT_nistp256: 111 case PCT_nistp521: 112 break; 113 #endif 114 case PCT_ec: 115 EC_ec_pre_comp_free(group->pre_comp.ec); 116 break; 117 } 118 group->pre_comp.ec = NULL; 119 } 120 121 void EC_GROUP_free(EC_GROUP *group) 122 { 123 if (!group) 124 return; 125 126 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_free(group->generator); 132 BN_free(group->order); 133 BN_free(group->cofactor); 134 OPENSSL_free(group->seed); 135 OPENSSL_free(group->propq); 136 OPENSSL_free(group); 137 } 138 139 #ifndef OPENSSL_NO_DEPRECATED_3_0 140 void EC_GROUP_clear_free(EC_GROUP *group) 141 { 142 if (!group) 143 return; 144 145 if (group->meth->group_clear_finish != 0) 146 group->meth->group_clear_finish(group); 147 else if (group->meth->group_finish != 0) 148 group->meth->group_finish(group); 149 150 EC_pre_comp_free(group); 151 BN_MONT_CTX_free(group->mont_data); 152 EC_POINT_clear_free(group->generator); 153 BN_clear_free(group->order); 154 BN_clear_free(group->cofactor); 155 OPENSSL_clear_free(group->seed, group->seed_len); 156 OPENSSL_clear_free(group, sizeof(*group)); 157 } 158 #endif 159 160 int EC_GROUP_copy(EC_GROUP *dest, const EC_GROUP *src) 161 { 162 if (dest->meth->group_copy == 0) { 163 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 164 return 0; 165 } 166 if (dest->meth != src->meth) { 167 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 168 return 0; 169 } 170 if (dest == src) 171 return 1; 172 173 dest->libctx = src->libctx; 174 dest->curve_name = src->curve_name; 175 176 /* Copy precomputed */ 177 dest->pre_comp_type = src->pre_comp_type; 178 switch (src->pre_comp_type) { 179 case PCT_none: 180 dest->pre_comp.ec = NULL; 181 break; 182 case PCT_nistz256: 183 #ifdef ECP_NISTZ256_ASM 184 dest->pre_comp.nistz256 = EC_nistz256_pre_comp_dup(src->pre_comp.nistz256); 185 #endif 186 break; 187 #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128 188 case PCT_nistp224: 189 dest->pre_comp.nistp224 = EC_nistp224_pre_comp_dup(src->pre_comp.nistp224); 190 break; 191 case PCT_nistp256: 192 dest->pre_comp.nistp256 = EC_nistp256_pre_comp_dup(src->pre_comp.nistp256); 193 break; 194 case PCT_nistp521: 195 dest->pre_comp.nistp521 = EC_nistp521_pre_comp_dup(src->pre_comp.nistp521); 196 break; 197 #else 198 case PCT_nistp224: 199 case PCT_nistp256: 200 case PCT_nistp521: 201 break; 202 #endif 203 case PCT_ec: 204 dest->pre_comp.ec = EC_ec_pre_comp_dup(src->pre_comp.ec); 205 break; 206 } 207 208 if (src->mont_data != NULL) { 209 if (dest->mont_data == NULL) { 210 dest->mont_data = BN_MONT_CTX_new(); 211 if (dest->mont_data == NULL) 212 return 0; 213 } 214 if (!BN_MONT_CTX_copy(dest->mont_data, src->mont_data)) 215 return 0; 216 } else { 217 /* src->generator == NULL */ 218 BN_MONT_CTX_free(dest->mont_data); 219 dest->mont_data = NULL; 220 } 221 222 if (src->generator != NULL) { 223 if (dest->generator == NULL) { 224 dest->generator = EC_POINT_new(dest); 225 if (dest->generator == NULL) 226 return 0; 227 } 228 if (!EC_POINT_copy(dest->generator, src->generator)) 229 return 0; 230 } else { 231 /* src->generator == NULL */ 232 EC_POINT_clear_free(dest->generator); 233 dest->generator = NULL; 234 } 235 236 if ((src->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) { 237 if (!BN_copy(dest->order, src->order)) 238 return 0; 239 if (!BN_copy(dest->cofactor, src->cofactor)) 240 return 0; 241 } 242 243 dest->asn1_flag = src->asn1_flag; 244 dest->asn1_form = src->asn1_form; 245 dest->decoded_from_explicit_params = src->decoded_from_explicit_params; 246 247 if (src->seed) { 248 OPENSSL_free(dest->seed); 249 if ((dest->seed = OPENSSL_malloc(src->seed_len)) == NULL) { 250 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE); 251 return 0; 252 } 253 if (!memcpy(dest->seed, src->seed, src->seed_len)) 254 return 0; 255 dest->seed_len = src->seed_len; 256 } else { 257 OPENSSL_free(dest->seed); 258 dest->seed = NULL; 259 dest->seed_len = 0; 260 } 261 262 return dest->meth->group_copy(dest, src); 263 } 264 265 EC_GROUP *EC_GROUP_dup(const EC_GROUP *a) 266 { 267 EC_GROUP *t = NULL; 268 int ok = 0; 269 270 if (a == NULL) 271 return NULL; 272 273 if ((t = ossl_ec_group_new_ex(a->libctx, a->propq, a->meth)) == NULL) 274 return NULL; 275 if (!EC_GROUP_copy(t, a)) 276 goto err; 277 278 ok = 1; 279 280 err: 281 if (!ok) { 282 EC_GROUP_free(t); 283 return NULL; 284 } 285 return t; 286 } 287 288 #ifndef OPENSSL_NO_DEPRECATED_3_0 289 const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group) 290 { 291 return group->meth; 292 } 293 294 int EC_METHOD_get_field_type(const EC_METHOD *meth) 295 { 296 return meth->field_type; 297 } 298 #endif 299 300 static int ec_precompute_mont_data(EC_GROUP *); 301 302 /*- 303 * Try computing cofactor from the generator order (n) and field cardinality (q). 304 * This works for all curves of cryptographic interest. 305 * 306 * Hasse thm: q + 1 - 2*sqrt(q) <= n*h <= q + 1 + 2*sqrt(q) 307 * h_min = (q + 1 - 2*sqrt(q))/n 308 * h_max = (q + 1 + 2*sqrt(q))/n 309 * h_max - h_min = 4*sqrt(q)/n 310 * So if n > 4*sqrt(q) holds, there is only one possible value for h: 311 * h = \lfloor (h_min + h_max)/2 \rceil = \lfloor (q + 1)/n \rceil 312 * 313 * Otherwise, zero cofactor and return success. 314 */ 315 static int ec_guess_cofactor(EC_GROUP *group) { 316 int ret = 0; 317 BN_CTX *ctx = NULL; 318 BIGNUM *q = NULL; 319 320 /*- 321 * If the cofactor is too large, we cannot guess it. 322 * The RHS of below is a strict overestimate of lg(4 * sqrt(q)) 323 */ 324 if (BN_num_bits(group->order) <= (BN_num_bits(group->field) + 1) / 2 + 3) { 325 /* default to 0 */ 326 BN_zero(group->cofactor); 327 /* return success */ 328 return 1; 329 } 330 331 if ((ctx = BN_CTX_new_ex(group->libctx)) == NULL) 332 return 0; 333 334 BN_CTX_start(ctx); 335 if ((q = BN_CTX_get(ctx)) == NULL) 336 goto err; 337 338 /* set q = 2**m for binary fields; q = p otherwise */ 339 if (group->meth->field_type == NID_X9_62_characteristic_two_field) { 340 BN_zero(q); 341 if (!BN_set_bit(q, BN_num_bits(group->field) - 1)) 342 goto err; 343 } else { 344 if (!BN_copy(q, group->field)) 345 goto err; 346 } 347 348 /* compute h = \lfloor (q + 1)/n \rceil = \lfloor (q + 1 + n/2)/n \rfloor */ 349 if (!BN_rshift1(group->cofactor, group->order) /* n/2 */ 350 || !BN_add(group->cofactor, group->cofactor, q) /* q + n/2 */ 351 /* q + 1 + n/2 */ 352 || !BN_add(group->cofactor, group->cofactor, BN_value_one()) 353 /* (q + 1 + n/2)/n */ 354 || !BN_div(group->cofactor, NULL, group->cofactor, group->order, ctx)) 355 goto err; 356 ret = 1; 357 err: 358 BN_CTX_end(ctx); 359 BN_CTX_free(ctx); 360 return ret; 361 } 362 363 int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator, 364 const BIGNUM *order, const BIGNUM *cofactor) 365 { 366 if (generator == NULL) { 367 ERR_raise(ERR_LIB_EC, ERR_R_PASSED_NULL_PARAMETER); 368 return 0; 369 } 370 371 /* require group->field >= 1 */ 372 if (group->field == NULL || BN_is_zero(group->field) 373 || BN_is_negative(group->field)) { 374 ERR_raise(ERR_LIB_EC, EC_R_INVALID_FIELD); 375 return 0; 376 } 377 378 /*- 379 * - require order >= 1 380 * - enforce upper bound due to Hasse thm: order can be no more than one bit 381 * longer than field cardinality 382 */ 383 if (order == NULL || BN_is_zero(order) || BN_is_negative(order) 384 || BN_num_bits(order) > BN_num_bits(group->field) + 1) { 385 ERR_raise(ERR_LIB_EC, EC_R_INVALID_GROUP_ORDER); 386 return 0; 387 } 388 389 /*- 390 * Unfortunately the cofactor is an optional field in many standards. 391 * Internally, the lib uses 0 cofactor as a marker for "unknown cofactor". 392 * So accept cofactor == NULL or cofactor >= 0. 393 */ 394 if (cofactor != NULL && BN_is_negative(cofactor)) { 395 ERR_raise(ERR_LIB_EC, EC_R_UNKNOWN_COFACTOR); 396 return 0; 397 } 398 399 if (group->generator == NULL) { 400 group->generator = EC_POINT_new(group); 401 if (group->generator == NULL) 402 return 0; 403 } 404 if (!EC_POINT_copy(group->generator, generator)) 405 return 0; 406 407 if (!BN_copy(group->order, order)) 408 return 0; 409 410 /* Either take the provided positive cofactor, or try to compute it */ 411 if (cofactor != NULL && !BN_is_zero(cofactor)) { 412 if (!BN_copy(group->cofactor, cofactor)) 413 return 0; 414 } else if (!ec_guess_cofactor(group)) { 415 BN_zero(group->cofactor); 416 return 0; 417 } 418 419 /* 420 * Some groups have an order with 421 * factors of two, which makes the Montgomery setup fail. 422 * |group->mont_data| will be NULL in this case. 423 */ 424 if (BN_is_odd(group->order)) { 425 return ec_precompute_mont_data(group); 426 } 427 428 BN_MONT_CTX_free(group->mont_data); 429 group->mont_data = NULL; 430 return 1; 431 } 432 433 const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group) 434 { 435 return group->generator; 436 } 437 438 BN_MONT_CTX *EC_GROUP_get_mont_data(const EC_GROUP *group) 439 { 440 return group->mont_data; 441 } 442 443 int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, BN_CTX *ctx) 444 { 445 if (group->order == NULL) 446 return 0; 447 if (!BN_copy(order, group->order)) 448 return 0; 449 450 return !BN_is_zero(order); 451 } 452 453 const BIGNUM *EC_GROUP_get0_order(const EC_GROUP *group) 454 { 455 return group->order; 456 } 457 458 int EC_GROUP_order_bits(const EC_GROUP *group) 459 { 460 return group->meth->group_order_bits(group); 461 } 462 463 int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor, 464 BN_CTX *ctx) 465 { 466 467 if (group->cofactor == NULL) 468 return 0; 469 if (!BN_copy(cofactor, group->cofactor)) 470 return 0; 471 472 return !BN_is_zero(group->cofactor); 473 } 474 475 const BIGNUM *EC_GROUP_get0_cofactor(const EC_GROUP *group) 476 { 477 return group->cofactor; 478 } 479 480 void EC_GROUP_set_curve_name(EC_GROUP *group, int nid) 481 { 482 group->curve_name = nid; 483 group->asn1_flag = 484 (nid != NID_undef) 485 ? OPENSSL_EC_NAMED_CURVE 486 : OPENSSL_EC_EXPLICIT_CURVE; 487 } 488 489 int EC_GROUP_get_curve_name(const EC_GROUP *group) 490 { 491 return group->curve_name; 492 } 493 494 const BIGNUM *EC_GROUP_get0_field(const EC_GROUP *group) 495 { 496 return group->field; 497 } 498 499 int EC_GROUP_get_field_type(const EC_GROUP *group) 500 { 501 return group->meth->field_type; 502 } 503 504 void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag) 505 { 506 group->asn1_flag = flag; 507 } 508 509 int EC_GROUP_get_asn1_flag(const EC_GROUP *group) 510 { 511 return group->asn1_flag; 512 } 513 514 void EC_GROUP_set_point_conversion_form(EC_GROUP *group, 515 point_conversion_form_t form) 516 { 517 group->asn1_form = form; 518 } 519 520 point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP 521 *group) 522 { 523 return group->asn1_form; 524 } 525 526 size_t EC_GROUP_set_seed(EC_GROUP *group, const unsigned char *p, size_t len) 527 { 528 OPENSSL_free(group->seed); 529 group->seed = NULL; 530 group->seed_len = 0; 531 532 if (!len || !p) 533 return 1; 534 535 if ((group->seed = OPENSSL_malloc(len)) == NULL) { 536 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE); 537 return 0; 538 } 539 memcpy(group->seed, p, len); 540 group->seed_len = len; 541 542 return len; 543 } 544 545 unsigned char *EC_GROUP_get0_seed(const EC_GROUP *group) 546 { 547 return group->seed; 548 } 549 550 size_t EC_GROUP_get_seed_len(const EC_GROUP *group) 551 { 552 return group->seed_len; 553 } 554 555 int EC_GROUP_set_curve(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, 556 const BIGNUM *b, BN_CTX *ctx) 557 { 558 if (group->meth->group_set_curve == 0) { 559 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 560 return 0; 561 } 562 return group->meth->group_set_curve(group, p, a, b, ctx); 563 } 564 565 int EC_GROUP_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, 566 BN_CTX *ctx) 567 { 568 if (group->meth->group_get_curve == NULL) { 569 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 570 return 0; 571 } 572 return group->meth->group_get_curve(group, p, a, b, ctx); 573 } 574 575 #ifndef OPENSSL_NO_DEPRECATED_3_0 576 int EC_GROUP_set_curve_GFp(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, 577 const BIGNUM *b, BN_CTX *ctx) 578 { 579 return EC_GROUP_set_curve(group, p, a, b, ctx); 580 } 581 582 int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, 583 BIGNUM *b, BN_CTX *ctx) 584 { 585 return EC_GROUP_get_curve(group, p, a, b, ctx); 586 } 587 588 # ifndef OPENSSL_NO_EC2M 589 int EC_GROUP_set_curve_GF2m(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, 590 const BIGNUM *b, BN_CTX *ctx) 591 { 592 return EC_GROUP_set_curve(group, p, a, b, ctx); 593 } 594 595 int EC_GROUP_get_curve_GF2m(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, 596 BIGNUM *b, BN_CTX *ctx) 597 { 598 return EC_GROUP_get_curve(group, p, a, b, ctx); 599 } 600 # endif 601 #endif 602 603 int EC_GROUP_get_degree(const EC_GROUP *group) 604 { 605 if (group->meth->group_get_degree == 0) { 606 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 607 return 0; 608 } 609 return group->meth->group_get_degree(group); 610 } 611 612 int EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx) 613 { 614 if (group->meth->group_check_discriminant == 0) { 615 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 616 return 0; 617 } 618 return group->meth->group_check_discriminant(group, ctx); 619 } 620 621 int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ctx) 622 { 623 int r = 0; 624 BIGNUM *a1, *a2, *a3, *b1, *b2, *b3; 625 #ifndef FIPS_MODULE 626 BN_CTX *ctx_new = NULL; 627 #endif 628 629 /* compare the field types */ 630 if (EC_GROUP_get_field_type(a) != EC_GROUP_get_field_type(b)) 631 return 1; 632 /* compare the curve name (if present in both) */ 633 if (EC_GROUP_get_curve_name(a) && EC_GROUP_get_curve_name(b) && 634 EC_GROUP_get_curve_name(a) != EC_GROUP_get_curve_name(b)) 635 return 1; 636 if (a->meth->flags & EC_FLAGS_CUSTOM_CURVE) 637 return 0; 638 639 #ifndef FIPS_MODULE 640 if (ctx == NULL) 641 ctx_new = ctx = BN_CTX_new(); 642 #endif 643 if (ctx == NULL) 644 return -1; 645 646 BN_CTX_start(ctx); 647 a1 = BN_CTX_get(ctx); 648 a2 = BN_CTX_get(ctx); 649 a3 = BN_CTX_get(ctx); 650 b1 = BN_CTX_get(ctx); 651 b2 = BN_CTX_get(ctx); 652 b3 = BN_CTX_get(ctx); 653 if (b3 == NULL) { 654 BN_CTX_end(ctx); 655 #ifndef FIPS_MODULE 656 BN_CTX_free(ctx_new); 657 #endif 658 return -1; 659 } 660 661 /* 662 * XXX This approach assumes that the external representation of curves 663 * over the same field type is the same. 664 */ 665 if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) || 666 !b->meth->group_get_curve(b, b1, b2, b3, ctx)) 667 r = 1; 668 669 /* return 1 if the curve parameters are different */ 670 if (r || BN_cmp(a1, b1) != 0 || BN_cmp(a2, b2) != 0 || BN_cmp(a3, b3) != 0) 671 r = 1; 672 673 /* XXX EC_POINT_cmp() assumes that the methods are equal */ 674 /* return 1 if the generators are different */ 675 if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a), 676 EC_GROUP_get0_generator(b), ctx) != 0) 677 r = 1; 678 679 if (!r) { 680 const BIGNUM *ao, *bo, *ac, *bc; 681 /* compare the orders */ 682 ao = EC_GROUP_get0_order(a); 683 bo = EC_GROUP_get0_order(b); 684 if (ao == NULL || bo == NULL) { 685 /* return an error if either order is NULL */ 686 r = -1; 687 goto end; 688 } 689 if (BN_cmp(ao, bo) != 0) { 690 /* return 1 if orders are different */ 691 r = 1; 692 goto end; 693 } 694 /* 695 * It gets here if the curve parameters and generator matched. 696 * Now check the optional cofactors (if both are present). 697 */ 698 ac = EC_GROUP_get0_cofactor(a); 699 bc = EC_GROUP_get0_cofactor(b); 700 /* Returns 1 (mismatch) if both cofactors are specified and different */ 701 if (!BN_is_zero(ac) && !BN_is_zero(bc) && BN_cmp(ac, bc) != 0) 702 r = 1; 703 /* Returns 0 if the parameters matched */ 704 } 705 end: 706 BN_CTX_end(ctx); 707 #ifndef FIPS_MODULE 708 BN_CTX_free(ctx_new); 709 #endif 710 return r; 711 } 712 713 /* functions for EC_POINT objects */ 714 715 EC_POINT *EC_POINT_new(const EC_GROUP *group) 716 { 717 EC_POINT *ret; 718 719 if (group == NULL) { 720 ERR_raise(ERR_LIB_EC, ERR_R_PASSED_NULL_PARAMETER); 721 return NULL; 722 } 723 if (group->meth->point_init == NULL) { 724 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 725 return NULL; 726 } 727 728 ret = OPENSSL_zalloc(sizeof(*ret)); 729 if (ret == NULL) { 730 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE); 731 return NULL; 732 } 733 734 ret->meth = group->meth; 735 ret->curve_name = group->curve_name; 736 737 if (!ret->meth->point_init(ret)) { 738 OPENSSL_free(ret); 739 return NULL; 740 } 741 742 return ret; 743 } 744 745 void EC_POINT_free(EC_POINT *point) 746 { 747 if (point == NULL) 748 return; 749 750 if (point->meth->point_finish != 0) 751 point->meth->point_finish(point); 752 OPENSSL_free(point); 753 } 754 755 void EC_POINT_clear_free(EC_POINT *point) 756 { 757 if (point == NULL) 758 return; 759 760 if (point->meth->point_clear_finish != 0) 761 point->meth->point_clear_finish(point); 762 else if (point->meth->point_finish != 0) 763 point->meth->point_finish(point); 764 OPENSSL_clear_free(point, sizeof(*point)); 765 } 766 767 int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src) 768 { 769 if (dest->meth->point_copy == 0) { 770 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 771 return 0; 772 } 773 if (dest->meth != src->meth 774 || (dest->curve_name != src->curve_name 775 && dest->curve_name != 0 776 && src->curve_name != 0)) { 777 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 778 return 0; 779 } 780 if (dest == src) 781 return 1; 782 return dest->meth->point_copy(dest, src); 783 } 784 785 EC_POINT *EC_POINT_dup(const EC_POINT *a, const EC_GROUP *group) 786 { 787 EC_POINT *t; 788 int r; 789 790 if (a == NULL) 791 return NULL; 792 793 t = EC_POINT_new(group); 794 if (t == NULL) 795 return NULL; 796 r = EC_POINT_copy(t, a); 797 if (!r) { 798 EC_POINT_free(t); 799 return NULL; 800 } 801 return t; 802 } 803 804 #ifndef OPENSSL_NO_DEPRECATED_3_0 805 const EC_METHOD *EC_POINT_method_of(const EC_POINT *point) 806 { 807 return point->meth; 808 } 809 #endif 810 811 int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point) 812 { 813 if (group->meth->point_set_to_infinity == 0) { 814 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 815 return 0; 816 } 817 if (group->meth != point->meth) { 818 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 819 return 0; 820 } 821 return group->meth->point_set_to_infinity(group, point); 822 } 823 824 #ifndef OPENSSL_NO_DEPRECATED_3_0 825 int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group, 826 EC_POINT *point, const BIGNUM *x, 827 const BIGNUM *y, const BIGNUM *z, 828 BN_CTX *ctx) 829 { 830 if (group->meth->field_type != NID_X9_62_prime_field) { 831 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 832 return 0; 833 } 834 if (!ec_point_is_compat(point, group)) { 835 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 836 return 0; 837 } 838 return ossl_ec_GFp_simple_set_Jprojective_coordinates_GFp(group, point, 839 x, y, z, ctx); 840 } 841 842 int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group, 843 const EC_POINT *point, BIGNUM *x, 844 BIGNUM *y, BIGNUM *z, 845 BN_CTX *ctx) 846 { 847 if (group->meth->field_type != NID_X9_62_prime_field) { 848 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 849 return 0; 850 } 851 if (!ec_point_is_compat(point, group)) { 852 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 853 return 0; 854 } 855 return ossl_ec_GFp_simple_get_Jprojective_coordinates_GFp(group, point, 856 x, y, z, ctx); 857 } 858 #endif 859 860 int EC_POINT_set_affine_coordinates(const EC_GROUP *group, EC_POINT *point, 861 const BIGNUM *x, const BIGNUM *y, 862 BN_CTX *ctx) 863 { 864 if (group->meth->point_set_affine_coordinates == NULL) { 865 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 866 return 0; 867 } 868 if (!ec_point_is_compat(point, group)) { 869 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 870 return 0; 871 } 872 if (!group->meth->point_set_affine_coordinates(group, point, x, y, ctx)) 873 return 0; 874 875 if (EC_POINT_is_on_curve(group, point, ctx) <= 0) { 876 ERR_raise(ERR_LIB_EC, EC_R_POINT_IS_NOT_ON_CURVE); 877 return 0; 878 } 879 return 1; 880 } 881 882 #ifndef OPENSSL_NO_DEPRECATED_3_0 883 int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group, 884 EC_POINT *point, const BIGNUM *x, 885 const BIGNUM *y, BN_CTX *ctx) 886 { 887 return EC_POINT_set_affine_coordinates(group, point, x, y, ctx); 888 } 889 890 # ifndef OPENSSL_NO_EC2M 891 int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group, 892 EC_POINT *point, const BIGNUM *x, 893 const BIGNUM *y, BN_CTX *ctx) 894 { 895 return EC_POINT_set_affine_coordinates(group, point, x, y, ctx); 896 } 897 # endif 898 #endif 899 900 int EC_POINT_get_affine_coordinates(const EC_GROUP *group, 901 const EC_POINT *point, BIGNUM *x, BIGNUM *y, 902 BN_CTX *ctx) 903 { 904 if (group->meth->point_get_affine_coordinates == NULL) { 905 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 906 return 0; 907 } 908 if (!ec_point_is_compat(point, group)) { 909 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 910 return 0; 911 } 912 if (EC_POINT_is_at_infinity(group, point)) { 913 ERR_raise(ERR_LIB_EC, EC_R_POINT_AT_INFINITY); 914 return 0; 915 } 916 return group->meth->point_get_affine_coordinates(group, point, x, y, ctx); 917 } 918 919 #ifndef OPENSSL_NO_DEPRECATED_3_0 920 int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group, 921 const EC_POINT *point, BIGNUM *x, 922 BIGNUM *y, BN_CTX *ctx) 923 { 924 return EC_POINT_get_affine_coordinates(group, point, x, y, ctx); 925 } 926 927 # ifndef OPENSSL_NO_EC2M 928 int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group, 929 const EC_POINT *point, BIGNUM *x, 930 BIGNUM *y, BN_CTX *ctx) 931 { 932 return EC_POINT_get_affine_coordinates(group, point, x, y, ctx); 933 } 934 # endif 935 #endif 936 937 int EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, 938 const EC_POINT *b, BN_CTX *ctx) 939 { 940 if (group->meth->add == 0) { 941 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 942 return 0; 943 } 944 if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group) 945 || !ec_point_is_compat(b, group)) { 946 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 947 return 0; 948 } 949 return group->meth->add(group, r, a, b, ctx); 950 } 951 952 int EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, 953 BN_CTX *ctx) 954 { 955 if (group->meth->dbl == 0) { 956 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 957 return 0; 958 } 959 if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group)) { 960 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 961 return 0; 962 } 963 return group->meth->dbl(group, r, a, ctx); 964 } 965 966 int EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx) 967 { 968 if (group->meth->invert == 0) { 969 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 970 return 0; 971 } 972 if (!ec_point_is_compat(a, group)) { 973 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 974 return 0; 975 } 976 return group->meth->invert(group, a, ctx); 977 } 978 979 int EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *point) 980 { 981 if (group->meth->is_at_infinity == 0) { 982 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 983 return 0; 984 } 985 if (!ec_point_is_compat(point, group)) { 986 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 987 return 0; 988 } 989 return group->meth->is_at_infinity(group, point); 990 } 991 992 /* 993 * Check whether an EC_POINT is on the curve or not. Note that the return 994 * value for this function should NOT be treated as a boolean. Return values: 995 * 1: The point is on the curve 996 * 0: The point is not on the curve 997 * -1: An error occurred 998 */ 999 int EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point, 1000 BN_CTX *ctx) 1001 { 1002 if (group->meth->is_on_curve == 0) { 1003 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1004 return 0; 1005 } 1006 if (!ec_point_is_compat(point, group)) { 1007 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 1008 return 0; 1009 } 1010 return group->meth->is_on_curve(group, point, ctx); 1011 } 1012 1013 int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b, 1014 BN_CTX *ctx) 1015 { 1016 if (group->meth->point_cmp == 0) { 1017 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1018 return -1; 1019 } 1020 if (!ec_point_is_compat(a, group) || !ec_point_is_compat(b, group)) { 1021 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 1022 return -1; 1023 } 1024 return group->meth->point_cmp(group, a, b, ctx); 1025 } 1026 1027 #ifndef OPENSSL_NO_DEPRECATED_3_0 1028 int EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx) 1029 { 1030 if (group->meth->make_affine == 0) { 1031 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1032 return 0; 1033 } 1034 if (!ec_point_is_compat(point, group)) { 1035 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 1036 return 0; 1037 } 1038 return group->meth->make_affine(group, point, ctx); 1039 } 1040 1041 int EC_POINTs_make_affine(const EC_GROUP *group, size_t num, 1042 EC_POINT *points[], BN_CTX *ctx) 1043 { 1044 size_t i; 1045 1046 if (group->meth->points_make_affine == 0) { 1047 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1048 return 0; 1049 } 1050 for (i = 0; i < num; i++) { 1051 if (!ec_point_is_compat(points[i], group)) { 1052 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 1053 return 0; 1054 } 1055 } 1056 return group->meth->points_make_affine(group, num, points, ctx); 1057 } 1058 #endif 1059 1060 /* 1061 * Functions for point multiplication. If group->meth->mul is 0, we use the 1062 * wNAF-based implementations in ec_mult.c; otherwise we dispatch through 1063 * methods. 1064 */ 1065 1066 #ifndef OPENSSL_NO_DEPRECATED_3_0 1067 int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar, 1068 size_t num, const EC_POINT *points[], 1069 const BIGNUM *scalars[], BN_CTX *ctx) 1070 { 1071 int ret = 0; 1072 size_t i = 0; 1073 #ifndef FIPS_MODULE 1074 BN_CTX *new_ctx = NULL; 1075 #endif 1076 1077 if (!ec_point_is_compat(r, group)) { 1078 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 1079 return 0; 1080 } 1081 1082 if (scalar == NULL && num == 0) 1083 return EC_POINT_set_to_infinity(group, r); 1084 1085 for (i = 0; i < num; i++) { 1086 if (!ec_point_is_compat(points[i], group)) { 1087 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 1088 return 0; 1089 } 1090 } 1091 1092 #ifndef FIPS_MODULE 1093 if (ctx == NULL) 1094 ctx = new_ctx = BN_CTX_secure_new(); 1095 #endif 1096 if (ctx == NULL) { 1097 ERR_raise(ERR_LIB_EC, ERR_R_INTERNAL_ERROR); 1098 return 0; 1099 } 1100 1101 if (group->meth->mul != NULL) 1102 ret = group->meth->mul(group, r, scalar, num, points, scalars, ctx); 1103 else 1104 /* use default */ 1105 ret = ossl_ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx); 1106 1107 #ifndef FIPS_MODULE 1108 BN_CTX_free(new_ctx); 1109 #endif 1110 return ret; 1111 } 1112 #endif 1113 1114 int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar, 1115 const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx) 1116 { 1117 int ret = 0; 1118 size_t num; 1119 #ifndef FIPS_MODULE 1120 BN_CTX *new_ctx = NULL; 1121 #endif 1122 1123 if (!ec_point_is_compat(r, group) 1124 || (point != NULL && !ec_point_is_compat(point, group))) { 1125 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS); 1126 return 0; 1127 } 1128 1129 if (g_scalar == NULL && p_scalar == NULL) 1130 return EC_POINT_set_to_infinity(group, r); 1131 1132 #ifndef FIPS_MODULE 1133 if (ctx == NULL) 1134 ctx = new_ctx = BN_CTX_secure_new(); 1135 #endif 1136 if (ctx == NULL) { 1137 ERR_raise(ERR_LIB_EC, ERR_R_INTERNAL_ERROR); 1138 return 0; 1139 } 1140 1141 num = (point != NULL && p_scalar != NULL) ? 1 : 0; 1142 if (group->meth->mul != NULL) 1143 ret = group->meth->mul(group, r, g_scalar, num, &point, &p_scalar, ctx); 1144 else 1145 /* use default */ 1146 ret = ossl_ec_wNAF_mul(group, r, g_scalar, num, &point, &p_scalar, ctx); 1147 1148 #ifndef FIPS_MODULE 1149 BN_CTX_free(new_ctx); 1150 #endif 1151 return ret; 1152 } 1153 1154 #ifndef OPENSSL_NO_DEPRECATED_3_0 1155 int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx) 1156 { 1157 if (group->meth->mul == 0) 1158 /* use default */ 1159 return ossl_ec_wNAF_precompute_mult(group, ctx); 1160 1161 if (group->meth->precompute_mult != 0) 1162 return group->meth->precompute_mult(group, ctx); 1163 else 1164 return 1; /* nothing to do, so report success */ 1165 } 1166 1167 int EC_GROUP_have_precompute_mult(const EC_GROUP *group) 1168 { 1169 if (group->meth->mul == 0) 1170 /* use default */ 1171 return ossl_ec_wNAF_have_precompute_mult(group); 1172 1173 if (group->meth->have_precompute_mult != 0) 1174 return group->meth->have_precompute_mult(group); 1175 else 1176 return 0; /* cannot tell whether precomputation has 1177 * been performed */ 1178 } 1179 #endif 1180 1181 /* 1182 * ec_precompute_mont_data sets |group->mont_data| from |group->order| and 1183 * returns one on success. On error it returns zero. 1184 */ 1185 static int ec_precompute_mont_data(EC_GROUP *group) 1186 { 1187 BN_CTX *ctx = BN_CTX_new_ex(group->libctx); 1188 int ret = 0; 1189 1190 BN_MONT_CTX_free(group->mont_data); 1191 group->mont_data = NULL; 1192 1193 if (ctx == NULL) 1194 goto err; 1195 1196 group->mont_data = BN_MONT_CTX_new(); 1197 if (group->mont_data == NULL) 1198 goto err; 1199 1200 if (!BN_MONT_CTX_set(group->mont_data, group->order, ctx)) { 1201 BN_MONT_CTX_free(group->mont_data); 1202 group->mont_data = NULL; 1203 goto err; 1204 } 1205 1206 ret = 1; 1207 1208 err: 1209 1210 BN_CTX_free(ctx); 1211 return ret; 1212 } 1213 1214 #ifndef FIPS_MODULE 1215 int EC_KEY_set_ex_data(EC_KEY *key, int idx, void *arg) 1216 { 1217 return CRYPTO_set_ex_data(&key->ex_data, idx, arg); 1218 } 1219 1220 void *EC_KEY_get_ex_data(const EC_KEY *key, int idx) 1221 { 1222 return CRYPTO_get_ex_data(&key->ex_data, idx); 1223 } 1224 #endif 1225 1226 int ossl_ec_group_simple_order_bits(const EC_GROUP *group) 1227 { 1228 if (group->order == NULL) 1229 return 0; 1230 return BN_num_bits(group->order); 1231 } 1232 1233 static int ec_field_inverse_mod_ord(const EC_GROUP *group, BIGNUM *r, 1234 const BIGNUM *x, BN_CTX *ctx) 1235 { 1236 BIGNUM *e = NULL; 1237 int ret = 0; 1238 #ifndef FIPS_MODULE 1239 BN_CTX *new_ctx = NULL; 1240 #endif 1241 1242 if (group->mont_data == NULL) 1243 return 0; 1244 1245 #ifndef FIPS_MODULE 1246 if (ctx == NULL) 1247 ctx = new_ctx = BN_CTX_secure_new(); 1248 #endif 1249 if (ctx == NULL) 1250 return 0; 1251 1252 BN_CTX_start(ctx); 1253 if ((e = BN_CTX_get(ctx)) == NULL) 1254 goto err; 1255 1256 /*- 1257 * We want inverse in constant time, therefore we utilize the fact 1258 * order must be prime and use Fermats Little Theorem instead. 1259 */ 1260 if (!BN_set_word(e, 2)) 1261 goto err; 1262 if (!BN_sub(e, group->order, e)) 1263 goto err; 1264 /*- 1265 * Exponent e is public. 1266 * No need for scatter-gather or BN_FLG_CONSTTIME. 1267 */ 1268 if (!BN_mod_exp_mont(r, x, e, group->order, ctx, group->mont_data)) 1269 goto err; 1270 1271 ret = 1; 1272 1273 err: 1274 BN_CTX_end(ctx); 1275 #ifndef FIPS_MODULE 1276 BN_CTX_free(new_ctx); 1277 #endif 1278 return ret; 1279 } 1280 1281 /*- 1282 * Default behavior, if group->meth->field_inverse_mod_ord is NULL: 1283 * - When group->order is even, this function returns an error. 1284 * - When group->order is otherwise composite, the correctness 1285 * of the output is not guaranteed. 1286 * - When x is outside the range [1, group->order), the correctness 1287 * of the output is not guaranteed. 1288 * - Otherwise, this function returns the multiplicative inverse in the 1289 * range [1, group->order). 1290 * 1291 * EC_METHODs must implement their own field_inverse_mod_ord for 1292 * other functionality. 1293 */ 1294 int ossl_ec_group_do_inverse_ord(const EC_GROUP *group, BIGNUM *res, 1295 const BIGNUM *x, BN_CTX *ctx) 1296 { 1297 if (group->meth->field_inverse_mod_ord != NULL) 1298 return group->meth->field_inverse_mod_ord(group, res, x, ctx); 1299 else 1300 return ec_field_inverse_mod_ord(group, res, x, ctx); 1301 } 1302 1303 /*- 1304 * Coordinate blinding for EC_POINT. 1305 * 1306 * The underlying EC_METHOD can optionally implement this function: 1307 * underlying implementations should return 0 on errors, or 1 on 1308 * success. 1309 * 1310 * This wrapper returns 1 in case the underlying EC_METHOD does not 1311 * support coordinate blinding. 1312 */ 1313 int ossl_ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, 1314 BN_CTX *ctx) 1315 { 1316 if (group->meth->blind_coordinates == NULL) 1317 return 1; /* ignore if not implemented */ 1318 1319 return group->meth->blind_coordinates(group, p, ctx); 1320 } 1321 1322 int EC_GROUP_get_basis_type(const EC_GROUP *group) 1323 { 1324 int i; 1325 1326 if (EC_GROUP_get_field_type(group) != NID_X9_62_characteristic_two_field) 1327 /* everything else is currently not supported */ 1328 return 0; 1329 1330 /* Find the last non-zero element of group->poly[] */ 1331 for (i = 0; 1332 i < (int)OSSL_NELEM(group->poly) && group->poly[i] != 0; 1333 i++) 1334 continue; 1335 1336 if (i == 4) 1337 return NID_X9_62_ppBasis; 1338 else if (i == 2) 1339 return NID_X9_62_tpBasis; 1340 else 1341 /* everything else is currently not supported */ 1342 return 0; 1343 } 1344 1345 #ifndef OPENSSL_NO_EC2M 1346 int EC_GROUP_get_trinomial_basis(const EC_GROUP *group, unsigned int *k) 1347 { 1348 if (group == NULL) 1349 return 0; 1350 1351 if (EC_GROUP_get_field_type(group) != NID_X9_62_characteristic_two_field 1352 || !((group->poly[0] != 0) && (group->poly[1] != 0) 1353 && (group->poly[2] == 0))) { 1354 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1355 return 0; 1356 } 1357 1358 if (k) 1359 *k = group->poly[1]; 1360 1361 return 1; 1362 } 1363 1364 int EC_GROUP_get_pentanomial_basis(const EC_GROUP *group, unsigned int *k1, 1365 unsigned int *k2, unsigned int *k3) 1366 { 1367 if (group == NULL) 1368 return 0; 1369 1370 if (EC_GROUP_get_field_type(group) != NID_X9_62_characteristic_two_field 1371 || !((group->poly[0] != 0) && (group->poly[1] != 0) 1372 && (group->poly[2] != 0) && (group->poly[3] != 0) 1373 && (group->poly[4] == 0))) { 1374 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1375 return 0; 1376 } 1377 1378 if (k1) 1379 *k1 = group->poly[3]; 1380 if (k2) 1381 *k2 = group->poly[2]; 1382 if (k3) 1383 *k3 = group->poly[1]; 1384 1385 return 1; 1386 } 1387 #endif 1388 1389 #ifndef FIPS_MODULE 1390 /* 1391 * Check if the explicit parameters group matches any built-in curves. 1392 * 1393 * We create a copy of the group just built, so that we can remove optional 1394 * fields for the lookup: we do this to avoid the possibility that one of 1395 * the optional parameters is used to force the library into using a less 1396 * performant and less secure EC_METHOD instead of the specialized one. 1397 * In any case, `seed` is not really used in any computation, while a 1398 * cofactor different from the one in the built-in table is just 1399 * mathematically wrong anyway and should not be used. 1400 */ 1401 static EC_GROUP *ec_group_explicit_to_named(const EC_GROUP *group, 1402 OSSL_LIB_CTX *libctx, 1403 const char *propq, 1404 BN_CTX *ctx) 1405 { 1406 EC_GROUP *ret_group = NULL, *dup = NULL; 1407 int curve_name_nid; 1408 1409 const EC_POINT *point = EC_GROUP_get0_generator(group); 1410 const BIGNUM *order = EC_GROUP_get0_order(group); 1411 int no_seed = (EC_GROUP_get0_seed(group) == NULL); 1412 1413 if ((dup = EC_GROUP_dup(group)) == NULL 1414 || EC_GROUP_set_seed(dup, NULL, 0) != 1 1415 || !EC_GROUP_set_generator(dup, point, order, NULL)) 1416 goto err; 1417 if ((curve_name_nid = ossl_ec_curve_nid_from_params(dup, ctx)) != NID_undef) { 1418 /* 1419 * The input explicit parameters successfully matched one of the 1420 * built-in curves: often for built-in curves we have specialized 1421 * methods with better performance and hardening. 1422 * 1423 * In this case we replace the `EC_GROUP` created through explicit 1424 * parameters with one created from a named group. 1425 */ 1426 1427 # ifndef OPENSSL_NO_EC_NISTP_64_GCC_128 1428 /* 1429 * NID_wap_wsg_idm_ecid_wtls12 and NID_secp224r1 are both aliases for 1430 * the same curve, we prefer the SECP nid when matching explicit 1431 * parameters as that is associated with a specialized EC_METHOD. 1432 */ 1433 if (curve_name_nid == NID_wap_wsg_idm_ecid_wtls12) 1434 curve_name_nid = NID_secp224r1; 1435 # endif /* !def(OPENSSL_NO_EC_NISTP_64_GCC_128) */ 1436 1437 ret_group = EC_GROUP_new_by_curve_name_ex(libctx, propq, curve_name_nid); 1438 if (ret_group == NULL) 1439 goto err; 1440 1441 /* 1442 * Set the flag so that EC_GROUPs created from explicit parameters are 1443 * serialized using explicit parameters by default. 1444 */ 1445 EC_GROUP_set_asn1_flag(ret_group, OPENSSL_EC_EXPLICIT_CURVE); 1446 1447 /* 1448 * If the input params do not contain the optional seed field we make 1449 * sure it is not added to the returned group. 1450 * 1451 * The seed field is not really used inside libcrypto anyway, and 1452 * adding it to parsed explicit parameter keys would alter their DER 1453 * encoding output (because of the extra field) which could impact 1454 * applications fingerprinting keys by their DER encoding. 1455 */ 1456 if (no_seed) { 1457 if (EC_GROUP_set_seed(ret_group, NULL, 0) != 1) 1458 goto err; 1459 } 1460 } else { 1461 ret_group = (EC_GROUP *)group; 1462 } 1463 EC_GROUP_free(dup); 1464 return ret_group; 1465 err: 1466 EC_GROUP_free(dup); 1467 EC_GROUP_free(ret_group); 1468 return NULL; 1469 } 1470 #endif /* FIPS_MODULE */ 1471 1472 static EC_GROUP *group_new_from_name(const OSSL_PARAM *p, 1473 OSSL_LIB_CTX *libctx, const char *propq) 1474 { 1475 int ok = 0, nid; 1476 const char *curve_name = NULL; 1477 1478 switch (p->data_type) { 1479 case OSSL_PARAM_UTF8_STRING: 1480 /* The OSSL_PARAM functions have no support for this */ 1481 curve_name = p->data; 1482 ok = (curve_name != NULL); 1483 break; 1484 case OSSL_PARAM_UTF8_PTR: 1485 ok = OSSL_PARAM_get_utf8_ptr(p, &curve_name); 1486 break; 1487 } 1488 1489 if (ok) { 1490 nid = ossl_ec_curve_name2nid(curve_name); 1491 if (nid == NID_undef) { 1492 ERR_raise(ERR_LIB_EC, EC_R_INVALID_CURVE); 1493 return NULL; 1494 } else { 1495 return EC_GROUP_new_by_curve_name_ex(libctx, propq, nid); 1496 } 1497 } 1498 return NULL; 1499 } 1500 1501 /* These parameters can be set directly into an EC_GROUP */ 1502 int ossl_ec_group_set_params(EC_GROUP *group, const OSSL_PARAM params[]) 1503 { 1504 int encoding_flag = -1, format = -1; 1505 const OSSL_PARAM *p; 1506 1507 p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT); 1508 if (p != NULL) { 1509 if (!ossl_ec_pt_format_param2id(p, &format)) { 1510 ECerr(0, EC_R_INVALID_FORM); 1511 return 0; 1512 } 1513 EC_GROUP_set_point_conversion_form(group, format); 1514 } 1515 1516 p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_ENCODING); 1517 if (p != NULL) { 1518 if (!ossl_ec_encoding_param2id(p, &encoding_flag)) { 1519 ECerr(0, EC_R_INVALID_FORM); 1520 return 0; 1521 } 1522 EC_GROUP_set_asn1_flag(group, encoding_flag); 1523 } 1524 /* Optional seed */ 1525 p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_SEED); 1526 if (p != NULL) { 1527 /* The seed is allowed to be NULL */ 1528 if (p->data_type != OSSL_PARAM_OCTET_STRING 1529 || !EC_GROUP_set_seed(group, p->data, p->data_size)) { 1530 ECerr(0, EC_R_INVALID_SEED); 1531 return 0; 1532 } 1533 } 1534 return 1; 1535 } 1536 1537 EC_GROUP *EC_GROUP_new_from_params(const OSSL_PARAM params[], 1538 OSSL_LIB_CTX *libctx, const char *propq) 1539 { 1540 const OSSL_PARAM *ptmp; 1541 EC_GROUP *group = NULL; 1542 1543 #ifndef FIPS_MODULE 1544 const OSSL_PARAM *pa, *pb; 1545 int ok = 0; 1546 EC_GROUP *named_group = NULL; 1547 BIGNUM *p = NULL, *a = NULL, *b = NULL, *order = NULL, *cofactor = NULL; 1548 EC_POINT *point = NULL; 1549 int field_bits = 0; 1550 int is_prime_field = 1; 1551 BN_CTX *bnctx = NULL; 1552 const unsigned char *buf = NULL; 1553 int encoding_flag = -1; 1554 #endif 1555 1556 /* This is the simple named group case */ 1557 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_GROUP_NAME); 1558 if (ptmp != NULL) { 1559 int decoded = 0; 1560 1561 if ((group = group_new_from_name(ptmp, libctx, propq)) == NULL) 1562 return NULL; 1563 if (!ossl_ec_group_set_params(group, params)) { 1564 EC_GROUP_free(group); 1565 return NULL; 1566 } 1567 1568 ptmp = OSSL_PARAM_locate_const(params, 1569 OSSL_PKEY_PARAM_EC_DECODED_FROM_EXPLICIT_PARAMS); 1570 if (ptmp != NULL && !OSSL_PARAM_get_int(ptmp, &decoded)) { 1571 ERR_raise(ERR_LIB_EC, EC_R_WRONG_CURVE_PARAMETERS); 1572 EC_GROUP_free(group); 1573 return NULL; 1574 } 1575 group->decoded_from_explicit_params = decoded > 0; 1576 return group; 1577 } 1578 #ifdef FIPS_MODULE 1579 ERR_raise(ERR_LIB_EC, EC_R_EXPLICIT_PARAMS_NOT_SUPPORTED); 1580 return NULL; 1581 #else 1582 /* If it gets here then we are trying explicit parameters */ 1583 bnctx = BN_CTX_new_ex(libctx); 1584 if (bnctx == NULL) { 1585 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE); 1586 return 0; 1587 } 1588 BN_CTX_start(bnctx); 1589 1590 p = BN_CTX_get(bnctx); 1591 a = BN_CTX_get(bnctx); 1592 b = BN_CTX_get(bnctx); 1593 order = BN_CTX_get(bnctx); 1594 if (order == NULL) { 1595 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE); 1596 goto err; 1597 } 1598 1599 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_FIELD_TYPE); 1600 if (ptmp == NULL || ptmp->data_type != OSSL_PARAM_UTF8_STRING) { 1601 ERR_raise(ERR_LIB_EC, EC_R_INVALID_FIELD); 1602 goto err; 1603 } 1604 if (OPENSSL_strcasecmp(ptmp->data, SN_X9_62_prime_field) == 0) { 1605 is_prime_field = 1; 1606 } else if (OPENSSL_strcasecmp(ptmp->data, 1607 SN_X9_62_characteristic_two_field) == 0) { 1608 is_prime_field = 0; 1609 } else { 1610 /* Invalid field */ 1611 ERR_raise(ERR_LIB_EC, EC_R_UNSUPPORTED_FIELD); 1612 goto err; 1613 } 1614 1615 pa = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_A); 1616 if (!OSSL_PARAM_get_BN(pa, &a)) { 1617 ERR_raise(ERR_LIB_EC, EC_R_INVALID_A); 1618 goto err; 1619 } 1620 pb = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_B); 1621 if (!OSSL_PARAM_get_BN(pb, &b)) { 1622 ERR_raise(ERR_LIB_EC, EC_R_INVALID_B); 1623 goto err; 1624 } 1625 1626 /* extract the prime number or irreducible polynomial */ 1627 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_P); 1628 if (!OSSL_PARAM_get_BN(ptmp, &p)) { 1629 ERR_raise(ERR_LIB_EC, EC_R_INVALID_P); 1630 goto err; 1631 } 1632 1633 if (is_prime_field) { 1634 if (BN_is_negative(p) || BN_is_zero(p)) { 1635 ERR_raise(ERR_LIB_EC, EC_R_INVALID_P); 1636 goto err; 1637 } 1638 field_bits = BN_num_bits(p); 1639 if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS) { 1640 ERR_raise(ERR_LIB_EC, EC_R_FIELD_TOO_LARGE); 1641 goto err; 1642 } 1643 1644 /* create the EC_GROUP structure */ 1645 group = EC_GROUP_new_curve_GFp(p, a, b, bnctx); 1646 } else { 1647 # ifdef OPENSSL_NO_EC2M 1648 ERR_raise(ERR_LIB_EC, EC_R_GF2M_NOT_SUPPORTED); 1649 goto err; 1650 # else 1651 /* create the EC_GROUP structure */ 1652 group = EC_GROUP_new_curve_GF2m(p, a, b, NULL); 1653 if (group != NULL) { 1654 field_bits = EC_GROUP_get_degree(group); 1655 if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS) { 1656 ERR_raise(ERR_LIB_EC, EC_R_FIELD_TOO_LARGE); 1657 goto err; 1658 } 1659 } 1660 # endif /* OPENSSL_NO_EC2M */ 1661 } 1662 1663 if (group == NULL) { 1664 ERR_raise(ERR_LIB_EC, ERR_R_EC_LIB); 1665 goto err; 1666 } 1667 1668 /* Optional seed */ 1669 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_SEED); 1670 if (ptmp != NULL) { 1671 if (ptmp->data_type != OSSL_PARAM_OCTET_STRING) { 1672 ERR_raise(ERR_LIB_EC, EC_R_INVALID_SEED); 1673 goto err; 1674 } 1675 if (!EC_GROUP_set_seed(group, ptmp->data, ptmp->data_size)) 1676 goto err; 1677 } 1678 1679 /* generator base point */ 1680 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_GENERATOR); 1681 if (ptmp == NULL 1682 || ptmp->data_type != OSSL_PARAM_OCTET_STRING) { 1683 ERR_raise(ERR_LIB_EC, EC_R_INVALID_GENERATOR); 1684 goto err; 1685 } 1686 buf = (const unsigned char *)(ptmp->data); 1687 if ((point = EC_POINT_new(group)) == NULL) 1688 goto err; 1689 EC_GROUP_set_point_conversion_form(group, 1690 (point_conversion_form_t)buf[0] & ~0x01); 1691 if (!EC_POINT_oct2point(group, point, buf, ptmp->data_size, bnctx)) { 1692 ERR_raise(ERR_LIB_EC, EC_R_INVALID_GENERATOR); 1693 goto err; 1694 } 1695 1696 /* order */ 1697 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_ORDER); 1698 if (!OSSL_PARAM_get_BN(ptmp, &order) 1699 || (BN_is_negative(order) || BN_is_zero(order)) 1700 || (BN_num_bits(order) > (int)field_bits + 1)) { /* Hasse bound */ 1701 ERR_raise(ERR_LIB_EC, EC_R_INVALID_GROUP_ORDER); 1702 goto err; 1703 } 1704 1705 /* Optional cofactor */ 1706 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_COFACTOR); 1707 if (ptmp != NULL) { 1708 cofactor = BN_CTX_get(bnctx); 1709 if (cofactor == NULL || !OSSL_PARAM_get_BN(ptmp, &cofactor)) { 1710 ERR_raise(ERR_LIB_EC, EC_R_INVALID_COFACTOR); 1711 goto err; 1712 } 1713 } 1714 1715 /* set the generator, order and cofactor (if present) */ 1716 if (!EC_GROUP_set_generator(group, point, order, cofactor)) { 1717 ERR_raise(ERR_LIB_EC, EC_R_INVALID_GENERATOR); 1718 goto err; 1719 } 1720 1721 named_group = ec_group_explicit_to_named(group, libctx, propq, bnctx); 1722 if (named_group == NULL) { 1723 ERR_raise(ERR_LIB_EC, EC_R_INVALID_NAMED_GROUP_CONVERSION); 1724 goto err; 1725 } 1726 if (named_group == group) { 1727 /* 1728 * If we did not find a named group then the encoding should be explicit 1729 * if it was specified 1730 */ 1731 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_ENCODING); 1732 if (ptmp != NULL 1733 && !ossl_ec_encoding_param2id(ptmp, &encoding_flag)) { 1734 ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING); 1735 goto err; 1736 } 1737 if (encoding_flag == OPENSSL_EC_NAMED_CURVE) { 1738 ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING); 1739 goto err; 1740 } 1741 EC_GROUP_set_asn1_flag(group, OPENSSL_EC_EXPLICIT_CURVE); 1742 } else { 1743 EC_GROUP_free(group); 1744 group = named_group; 1745 } 1746 /* We've imported the group from explicit parameters, set it so. */ 1747 group->decoded_from_explicit_params = 1; 1748 ok = 1; 1749 err: 1750 if (!ok) { 1751 EC_GROUP_free(group); 1752 group = NULL; 1753 } 1754 EC_POINT_free(point); 1755 BN_CTX_end(bnctx); 1756 BN_CTX_free(bnctx); 1757 1758 return group; 1759 #endif /* FIPS_MODULE */ 1760 } 1761