1 /* $OpenBSD: ec_lib.c,v 1.45 2022/04/07 17:37:25 tb Exp $ */ 2 /* 3 * Originally written by Bodo Moeller for the OpenSSL project. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 1998-2003 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * openssl-core@openssl.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 * This product includes cryptographic software written by Eric Young 54 * (eay@cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh@cryptsoft.com). 56 * 57 */ 58 /* ==================================================================== 59 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. 60 * Binary polynomial ECC support in OpenSSL originally developed by 61 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project. 62 */ 63 64 #include <string.h> 65 66 #include <openssl/opensslconf.h> 67 68 #include <openssl/err.h> 69 #include <openssl/opensslv.h> 70 71 #include "bn_lcl.h" 72 #include "ec_lcl.h" 73 74 /* functions for EC_GROUP objects */ 75 76 EC_GROUP * 77 EC_GROUP_new(const EC_METHOD * meth) 78 { 79 EC_GROUP *ret; 80 81 if (meth == NULL) { 82 ECerror(EC_R_SLOT_FULL); 83 return NULL; 84 } 85 if (meth->group_init == 0) { 86 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 87 return NULL; 88 } 89 ret = malloc(sizeof *ret); 90 if (ret == NULL) { 91 ECerror(ERR_R_MALLOC_FAILURE); 92 return NULL; 93 } 94 ret->meth = meth; 95 96 ret->extra_data = NULL; 97 98 ret->generator = NULL; 99 BN_init(&ret->order); 100 BN_init(&ret->cofactor); 101 102 ret->curve_name = 0; 103 ret->asn1_flag = OPENSSL_EC_NAMED_CURVE; 104 ret->asn1_form = POINT_CONVERSION_UNCOMPRESSED; 105 106 ret->seed = NULL; 107 ret->seed_len = 0; 108 109 if (!meth->group_init(ret)) { 110 free(ret); 111 return NULL; 112 } 113 return ret; 114 } 115 116 117 void 118 EC_GROUP_free(EC_GROUP * group) 119 { 120 if (!group) 121 return; 122 123 if (group->meth->group_finish != 0) 124 group->meth->group_finish(group); 125 126 EC_EX_DATA_free_all_data(&group->extra_data); 127 128 EC_POINT_free(group->generator); 129 BN_free(&group->order); 130 BN_free(&group->cofactor); 131 132 free(group->seed); 133 134 free(group); 135 } 136 137 138 void 139 EC_GROUP_clear_free(EC_GROUP * group) 140 { 141 if (!group) 142 return; 143 144 if (group->meth->group_clear_finish != 0) 145 group->meth->group_clear_finish(group); 146 else if (group->meth->group_finish != 0) 147 group->meth->group_finish(group); 148 149 EC_EX_DATA_clear_free_all_data(&group->extra_data); 150 151 EC_POINT_clear_free(group->generator); 152 BN_clear_free(&group->order); 153 BN_clear_free(&group->cofactor); 154 155 freezero(group->seed, group->seed_len); 156 freezero(group, sizeof *group); 157 } 158 159 160 int 161 EC_GROUP_copy(EC_GROUP * dest, const EC_GROUP * src) 162 { 163 EC_EXTRA_DATA *d; 164 165 if (dest->meth->group_copy == 0) { 166 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 167 return 0; 168 } 169 if (dest->meth != src->meth) { 170 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 171 return 0; 172 } 173 if (dest == src) 174 return 1; 175 176 EC_EX_DATA_free_all_data(&dest->extra_data); 177 178 for (d = src->extra_data; d != NULL; d = d->next) { 179 void *t = d->dup_func(d->data); 180 181 if (t == NULL) 182 return 0; 183 if (!EC_EX_DATA_set_data(&dest->extra_data, t, d->dup_func, 184 d->free_func, d->clear_free_func)) 185 return 0; 186 } 187 188 if (src->generator != NULL) { 189 if (dest->generator == NULL) { 190 dest->generator = EC_POINT_new(dest); 191 if (dest->generator == NULL) 192 return 0; 193 } 194 if (!EC_POINT_copy(dest->generator, src->generator)) 195 return 0; 196 } else { 197 /* src->generator == NULL */ 198 EC_POINT_clear_free(dest->generator); 199 dest->generator = NULL; 200 } 201 202 if (!BN_copy(&dest->order, &src->order)) 203 return 0; 204 if (!BN_copy(&dest->cofactor, &src->cofactor)) 205 return 0; 206 207 dest->curve_name = src->curve_name; 208 dest->asn1_flag = src->asn1_flag; 209 dest->asn1_form = src->asn1_form; 210 211 if (src->seed) { 212 free(dest->seed); 213 dest->seed = malloc(src->seed_len); 214 if (dest->seed == NULL) 215 return 0; 216 memcpy(dest->seed, src->seed, src->seed_len); 217 dest->seed_len = src->seed_len; 218 } else { 219 free(dest->seed); 220 dest->seed = NULL; 221 dest->seed_len = 0; 222 } 223 224 225 return dest->meth->group_copy(dest, src); 226 } 227 228 229 EC_GROUP * 230 EC_GROUP_dup(const EC_GROUP * a) 231 { 232 EC_GROUP *t = NULL; 233 234 if ((a != NULL) && ((t = EC_GROUP_new(a->meth)) != NULL) && 235 (!EC_GROUP_copy(t, a))) { 236 EC_GROUP_free(t); 237 t = NULL; 238 } 239 return t; 240 } 241 242 243 const EC_METHOD * 244 EC_GROUP_method_of(const EC_GROUP *group) 245 { 246 return group->meth; 247 } 248 249 250 int 251 EC_METHOD_get_field_type(const EC_METHOD *meth) 252 { 253 return meth->field_type; 254 } 255 256 /* 257 * Try computing the cofactor from generator order n and field cardinality q. 258 * This works for all curves of cryptographic interest. 259 * 260 * Hasse's theorem: | h * n - (q + 1) | <= 2 * sqrt(q) 261 * 262 * So: h_min = (q + 1 - 2*sqrt(q)) / n and h_max = (q + 1 + 2*sqrt(q)) / n and 263 * therefore h_max - h_min = 4*sqrt(q) / n. So if n > 4*sqrt(q) holds, there is 264 * only one possible value for h: 265 * 266 * h = \lfloor (h_min + h_max)/2 \rceil = \lfloor (q + 1)/n \rceil 267 * 268 * Otherwise, zero cofactor and return success. 269 */ 270 static int 271 ec_guess_cofactor(EC_GROUP *group) 272 { 273 BN_CTX *ctx = NULL; 274 BIGNUM *q = NULL; 275 int ret = 0; 276 277 /* 278 * If the cofactor is too large, we cannot guess it and default to zero. 279 * The RHS of below is a strict overestimate of log(4 * sqrt(q)). 280 */ 281 if (BN_num_bits(&group->order) <= 282 (BN_num_bits(&group->field) + 1) / 2 + 3) { 283 BN_zero(&group->cofactor); 284 return 1; 285 } 286 287 if ((ctx = BN_CTX_new()) == NULL) 288 goto err; 289 290 BN_CTX_start(ctx); 291 if ((q = BN_CTX_get(ctx)) == NULL) 292 goto err; 293 294 /* Set q = 2**m for binary fields; q = p otherwise. */ 295 if (group->meth->field_type == NID_X9_62_characteristic_two_field) { 296 BN_zero(q); 297 if (!BN_set_bit(q, BN_num_bits(&group->field) - 1)) 298 goto err; 299 } else { 300 if (!BN_copy(q, &group->field)) 301 goto err; 302 } 303 304 /* 305 * Compute 306 * h = \lfloor (q + 1)/n \rceil = \lfloor (q + 1 + n/2) / n \rfloor. 307 */ 308 309 /* h = n/2 */ 310 if (!BN_rshift1(&group->cofactor, &group->order)) 311 goto err; 312 /* h = 1 + n/2 */ 313 if (!BN_add(&group->cofactor, &group->cofactor, BN_value_one())) 314 goto err; 315 /* h = q + 1 + n/2 */ 316 if (!BN_add(&group->cofactor, &group->cofactor, q)) 317 goto err; 318 /* h = (q + 1 + n/2) / n */ 319 if (!BN_div_ct(&group->cofactor, NULL, &group->cofactor, &group->order, 320 ctx)) 321 goto err; 322 323 ret = 1; 324 325 err: 326 BN_CTX_end(ctx); 327 BN_CTX_free(ctx); 328 329 if (ret != 1) 330 BN_zero(&group->cofactor); 331 332 return ret; 333 } 334 335 int 336 EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator, 337 const BIGNUM *order, const BIGNUM *cofactor) 338 { 339 if (generator == NULL) { 340 ECerror(ERR_R_PASSED_NULL_PARAMETER); 341 return 0; 342 } 343 344 /* Require group->field >= 1. */ 345 if (BN_is_zero(&group->field) || BN_is_negative(&group->field)) { 346 ECerror(EC_R_INVALID_FIELD); 347 return 0; 348 } 349 350 /* 351 * Require order > 1 and enforce an upper bound of at most one bit more 352 * than the field cardinality due to Hasse's theorem. 353 */ 354 if (order == NULL || BN_cmp(order, BN_value_one()) <= 0 || 355 BN_num_bits(order) > BN_num_bits(&group->field) + 1) { 356 ECerror(EC_R_INVALID_GROUP_ORDER); 357 return 0; 358 } 359 360 /* 361 * Unfortunately, the cofactor is an optional field in many standards. 362 * Internally, the library uses a 0 cofactor as a marker for "unknown 363 * cofactor". So accept cofactor == NULL or cofactor >= 0. 364 */ 365 if (cofactor != NULL && BN_is_negative(cofactor)) { 366 ECerror(EC_R_UNKNOWN_COFACTOR); 367 return 0; 368 } 369 370 if (group->generator == NULL) { 371 group->generator = EC_POINT_new(group); 372 if (group->generator == NULL) 373 return 0; 374 } 375 if (!EC_POINT_copy(group->generator, generator)) 376 return 0; 377 378 if (!BN_copy(&group->order, order)) 379 return 0; 380 381 /* Either take the provided positive cofactor, or try to compute it. */ 382 if (cofactor != NULL && !BN_is_zero(cofactor)) { 383 if (!BN_copy(&group->cofactor, cofactor)) 384 return 0; 385 } else if (!ec_guess_cofactor(group)) 386 return 0; 387 388 /* Use Hasse's theorem to bound the cofactor. */ 389 if (BN_num_bits(&group->cofactor) > BN_num_bits(&group->field) + 1) { 390 ECerror(EC_R_INVALID_GROUP_ORDER); 391 return 0; 392 } 393 394 return 1; 395 } 396 397 398 const EC_POINT * 399 EC_GROUP_get0_generator(const EC_GROUP *group) 400 { 401 return group->generator; 402 } 403 404 405 int 406 EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, BN_CTX *ctx) 407 { 408 if (!BN_copy(order, &group->order)) 409 return 0; 410 411 return !BN_is_zero(order); 412 } 413 414 int 415 EC_GROUP_order_bits(const EC_GROUP *group) 416 { 417 return group->meth->group_order_bits(group); 418 } 419 420 int 421 EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor, BN_CTX *ctx) 422 { 423 if (!BN_copy(cofactor, &group->cofactor)) 424 return 0; 425 426 return !BN_is_zero(&group->cofactor); 427 } 428 429 430 void 431 EC_GROUP_set_curve_name(EC_GROUP * group, int nid) 432 { 433 group->curve_name = nid; 434 } 435 436 437 int 438 EC_GROUP_get_curve_name(const EC_GROUP * group) 439 { 440 return group->curve_name; 441 } 442 443 444 void 445 EC_GROUP_set_asn1_flag(EC_GROUP * group, int flag) 446 { 447 group->asn1_flag = flag; 448 } 449 450 451 int 452 EC_GROUP_get_asn1_flag(const EC_GROUP * group) 453 { 454 return group->asn1_flag; 455 } 456 457 458 void 459 EC_GROUP_set_point_conversion_form(EC_GROUP * group, 460 point_conversion_form_t form) 461 { 462 group->asn1_form = form; 463 } 464 465 466 point_conversion_form_t 467 EC_GROUP_get_point_conversion_form(const EC_GROUP * group) 468 { 469 return group->asn1_form; 470 } 471 472 473 size_t 474 EC_GROUP_set_seed(EC_GROUP * group, const unsigned char *p, size_t len) 475 { 476 if (group->seed) { 477 free(group->seed); 478 group->seed = NULL; 479 group->seed_len = 0; 480 } 481 if (!len || !p) 482 return 1; 483 484 if ((group->seed = malloc(len)) == NULL) 485 return 0; 486 memcpy(group->seed, p, len); 487 group->seed_len = len; 488 489 return len; 490 } 491 492 493 unsigned char * 494 EC_GROUP_get0_seed(const EC_GROUP * group) 495 { 496 return group->seed; 497 } 498 499 500 size_t 501 EC_GROUP_get_seed_len(const EC_GROUP * group) 502 { 503 return group->seed_len; 504 } 505 506 int 507 EC_GROUP_set_curve(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, 508 const BIGNUM *b, BN_CTX *ctx) 509 { 510 if (group->meth->group_set_curve == NULL) { 511 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 512 return 0; 513 } 514 return group->meth->group_set_curve(group, p, a, b, ctx); 515 } 516 517 int 518 EC_GROUP_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, 519 BN_CTX *ctx) 520 { 521 if (group->meth->group_get_curve == NULL) { 522 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 523 return 0; 524 } 525 return group->meth->group_get_curve(group, p, a, b, ctx); 526 } 527 528 int 529 EC_GROUP_set_curve_GFp(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, 530 const BIGNUM *b, BN_CTX *ctx) 531 { 532 return EC_GROUP_set_curve(group, p, a, b, ctx); 533 } 534 535 int 536 EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, 537 BN_CTX *ctx) 538 { 539 return EC_GROUP_get_curve(group, p, a, b, ctx); 540 } 541 542 #ifndef OPENSSL_NO_EC2M 543 int 544 EC_GROUP_set_curve_GF2m(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, 545 const BIGNUM *b, BN_CTX *ctx) 546 { 547 return EC_GROUP_set_curve(group, p, a, b, ctx); 548 } 549 550 int 551 EC_GROUP_get_curve_GF2m(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, 552 BIGNUM *b, BN_CTX *ctx) 553 { 554 return EC_GROUP_get_curve(group, p, a, b, ctx); 555 } 556 #endif 557 558 int 559 EC_GROUP_get_degree(const EC_GROUP * group) 560 { 561 if (group->meth->group_get_degree == 0) { 562 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 563 return 0; 564 } 565 return group->meth->group_get_degree(group); 566 } 567 568 569 int 570 EC_GROUP_check_discriminant(const EC_GROUP * group, BN_CTX * ctx) 571 { 572 if (group->meth->group_check_discriminant == 0) { 573 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 574 return 0; 575 } 576 return group->meth->group_check_discriminant(group, ctx); 577 } 578 579 580 int 581 EC_GROUP_cmp(const EC_GROUP * a, const EC_GROUP * b, BN_CTX * ctx) 582 { 583 int r = 0; 584 BIGNUM *a1, *a2, *a3, *b1, *b2, *b3; 585 BN_CTX *ctx_new = NULL; 586 587 /* compare the field types */ 588 if (EC_METHOD_get_field_type(EC_GROUP_method_of(a)) != 589 EC_METHOD_get_field_type(EC_GROUP_method_of(b))) 590 return 1; 591 /* compare the curve name (if present in both) */ 592 if (EC_GROUP_get_curve_name(a) && EC_GROUP_get_curve_name(b) && 593 EC_GROUP_get_curve_name(a) != EC_GROUP_get_curve_name(b)) 594 return 1; 595 596 if (!ctx) 597 ctx_new = ctx = BN_CTX_new(); 598 if (!ctx) 599 return -1; 600 601 BN_CTX_start(ctx); 602 if ((a1 = BN_CTX_get(ctx)) == NULL) 603 goto err; 604 if ((a2 = BN_CTX_get(ctx)) == NULL) 605 goto err; 606 if ((a3 = BN_CTX_get(ctx)) == NULL) 607 goto err; 608 if ((b1 = BN_CTX_get(ctx)) == NULL) 609 goto err; 610 if ((b2 = BN_CTX_get(ctx)) == NULL) 611 goto err; 612 if ((b3 = BN_CTX_get(ctx)) == NULL) 613 goto err; 614 615 /* 616 * XXX This approach assumes that the external representation of 617 * curves over the same field type is the same. 618 */ 619 if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) || 620 !b->meth->group_get_curve(b, b1, b2, b3, ctx)) 621 r = 1; 622 623 if (r || BN_cmp(a1, b1) || BN_cmp(a2, b2) || BN_cmp(a3, b3)) 624 r = 1; 625 626 /* XXX EC_POINT_cmp() assumes that the methods are equal */ 627 if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a), 628 EC_GROUP_get0_generator(b), ctx)) 629 r = 1; 630 631 if (!r) { 632 /* compare the order and cofactor */ 633 if (!EC_GROUP_get_order(a, a1, ctx) || 634 !EC_GROUP_get_order(b, b1, ctx) || 635 !EC_GROUP_get_cofactor(a, a2, ctx) || 636 !EC_GROUP_get_cofactor(b, b2, ctx)) 637 goto err; 638 if (BN_cmp(a1, b1) || BN_cmp(a2, b2)) 639 r = 1; 640 } 641 BN_CTX_end(ctx); 642 if (ctx_new) 643 BN_CTX_free(ctx); 644 645 return r; 646 647 err: 648 BN_CTX_end(ctx); 649 if (ctx_new) 650 BN_CTX_free(ctx); 651 return -1; 652 } 653 654 /* 655 * Coordinate blinding for EC_POINT. 656 * 657 * The underlying EC_METHOD can optionally implement this function: 658 * underlying implementations should return 0 on errors, or 1 on success. 659 * 660 * This wrapper returns 1 in case the underlying EC_METHOD does not support 661 * coordinate blinding. 662 */ 663 int 664 ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx) 665 { 666 if (group->meth->blind_coordinates == NULL) 667 return 1; 668 669 return group->meth->blind_coordinates(group, p, ctx); 670 } 671 672 /* this has 'package' visibility */ 673 int 674 EC_EX_DATA_set_data(EC_EXTRA_DATA ** ex_data, void *data, 675 void *(*dup_func) (void *), 676 void (*free_func) (void *), 677 void (*clear_free_func) (void *)) 678 { 679 EC_EXTRA_DATA *d; 680 681 if (ex_data == NULL) 682 return 0; 683 684 for (d = *ex_data; d != NULL; d = d->next) { 685 if (d->dup_func == dup_func && d->free_func == free_func && 686 d->clear_free_func == clear_free_func) { 687 ECerror(EC_R_SLOT_FULL); 688 return 0; 689 } 690 } 691 692 if (data == NULL) 693 /* no explicit entry needed */ 694 return 1; 695 696 d = malloc(sizeof *d); 697 if (d == NULL) 698 return 0; 699 700 d->data = data; 701 d->dup_func = dup_func; 702 d->free_func = free_func; 703 d->clear_free_func = clear_free_func; 704 705 d->next = *ex_data; 706 *ex_data = d; 707 708 return 1; 709 } 710 711 /* this has 'package' visibility */ 712 void * 713 EC_EX_DATA_get_data(const EC_EXTRA_DATA * ex_data, 714 void *(*dup_func) (void *), 715 void (*free_func) (void *), 716 void (*clear_free_func) (void *)) 717 { 718 const EC_EXTRA_DATA *d; 719 720 for (d = ex_data; d != NULL; d = d->next) { 721 if (d->dup_func == dup_func && d->free_func == free_func && d->clear_free_func == clear_free_func) 722 return d->data; 723 } 724 725 return NULL; 726 } 727 728 /* this has 'package' visibility */ 729 void 730 EC_EX_DATA_free_data(EC_EXTRA_DATA ** ex_data, 731 void *(*dup_func) (void *), 732 void (*free_func) (void *), 733 void (*clear_free_func) (void *)) 734 { 735 EC_EXTRA_DATA **p; 736 737 if (ex_data == NULL) 738 return; 739 740 for (p = ex_data; *p != NULL; p = &((*p)->next)) { 741 if ((*p)->dup_func == dup_func && 742 (*p)->free_func == free_func && 743 (*p)->clear_free_func == clear_free_func) { 744 EC_EXTRA_DATA *next = (*p)->next; 745 746 (*p)->free_func((*p)->data); 747 free(*p); 748 749 *p = next; 750 return; 751 } 752 } 753 } 754 755 /* this has 'package' visibility */ 756 void 757 EC_EX_DATA_clear_free_data(EC_EXTRA_DATA ** ex_data, 758 void *(*dup_func) (void *), 759 void (*free_func) (void *), 760 void (*clear_free_func) (void *)) 761 { 762 EC_EXTRA_DATA **p; 763 764 if (ex_data == NULL) 765 return; 766 767 for (p = ex_data; *p != NULL; p = &((*p)->next)) { 768 if ((*p)->dup_func == dup_func && 769 (*p)->free_func == free_func && 770 (*p)->clear_free_func == clear_free_func) { 771 EC_EXTRA_DATA *next = (*p)->next; 772 773 (*p)->clear_free_func((*p)->data); 774 free(*p); 775 776 *p = next; 777 return; 778 } 779 } 780 } 781 782 /* this has 'package' visibility */ 783 void 784 EC_EX_DATA_free_all_data(EC_EXTRA_DATA ** ex_data) 785 { 786 EC_EXTRA_DATA *d; 787 788 if (ex_data == NULL) 789 return; 790 791 d = *ex_data; 792 while (d) { 793 EC_EXTRA_DATA *next = d->next; 794 795 d->free_func(d->data); 796 free(d); 797 798 d = next; 799 } 800 *ex_data = NULL; 801 } 802 803 /* this has 'package' visibility */ 804 void 805 EC_EX_DATA_clear_free_all_data(EC_EXTRA_DATA ** ex_data) 806 { 807 EC_EXTRA_DATA *d; 808 809 if (ex_data == NULL) 810 return; 811 812 d = *ex_data; 813 while (d) { 814 EC_EXTRA_DATA *next = d->next; 815 816 d->clear_free_func(d->data); 817 free(d); 818 819 d = next; 820 } 821 *ex_data = NULL; 822 } 823 824 825 /* functions for EC_POINT objects */ 826 827 EC_POINT * 828 EC_POINT_new(const EC_GROUP * group) 829 { 830 EC_POINT *ret; 831 832 if (group == NULL) { 833 ECerror(ERR_R_PASSED_NULL_PARAMETER); 834 return NULL; 835 } 836 if (group->meth->point_init == 0) { 837 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 838 return NULL; 839 } 840 ret = malloc(sizeof *ret); 841 if (ret == NULL) { 842 ECerror(ERR_R_MALLOC_FAILURE); 843 return NULL; 844 } 845 ret->meth = group->meth; 846 847 if (!ret->meth->point_init(ret)) { 848 free(ret); 849 return NULL; 850 } 851 return ret; 852 } 853 854 855 void 856 EC_POINT_free(EC_POINT * point) 857 { 858 if (!point) 859 return; 860 861 if (point->meth->point_finish != 0) 862 point->meth->point_finish(point); 863 free(point); 864 } 865 866 867 void 868 EC_POINT_clear_free(EC_POINT * point) 869 { 870 if (!point) 871 return; 872 873 if (point->meth->point_clear_finish != 0) 874 point->meth->point_clear_finish(point); 875 else if (point->meth->point_finish != 0) 876 point->meth->point_finish(point); 877 freezero(point, sizeof *point); 878 } 879 880 881 int 882 EC_POINT_copy(EC_POINT * dest, const EC_POINT * src) 883 { 884 if (dest->meth->point_copy == 0) { 885 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 886 return 0; 887 } 888 if (dest->meth != src->meth) { 889 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 890 return 0; 891 } 892 if (dest == src) 893 return 1; 894 return dest->meth->point_copy(dest, src); 895 } 896 897 898 EC_POINT * 899 EC_POINT_dup(const EC_POINT * a, const EC_GROUP * group) 900 { 901 EC_POINT *t; 902 int r; 903 904 if (a == NULL) 905 return NULL; 906 907 t = EC_POINT_new(group); 908 if (t == NULL) 909 return (NULL); 910 r = EC_POINT_copy(t, a); 911 if (!r) { 912 EC_POINT_free(t); 913 return NULL; 914 } else 915 return t; 916 } 917 918 919 const EC_METHOD * 920 EC_POINT_method_of(const EC_POINT * point) 921 { 922 return point->meth; 923 } 924 925 926 int 927 EC_POINT_set_to_infinity(const EC_GROUP * group, EC_POINT * point) 928 { 929 if (group->meth->point_set_to_infinity == 0) { 930 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 931 return 0; 932 } 933 if (group->meth != point->meth) { 934 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 935 return 0; 936 } 937 return group->meth->point_set_to_infinity(group, point); 938 } 939 940 int 941 EC_POINT_set_Jprojective_coordinates(const EC_GROUP *group, EC_POINT *point, 942 const BIGNUM *x, const BIGNUM *y, const BIGNUM *z, BN_CTX *ctx) 943 { 944 if (group->meth->point_set_Jprojective_coordinates == NULL) { 945 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 946 return 0; 947 } 948 if (group->meth != point->meth) { 949 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 950 return 0; 951 } 952 return group->meth->point_set_Jprojective_coordinates(group, point, 953 x, y, z, ctx); 954 } 955 956 int 957 EC_POINT_get_Jprojective_coordinates(const EC_GROUP *group, 958 const EC_POINT *point, BIGNUM *x, BIGNUM *y, BIGNUM *z, BN_CTX *ctx) 959 { 960 if (group->meth->point_get_Jprojective_coordinates == NULL) { 961 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 962 return 0; 963 } 964 if (group->meth != point->meth) { 965 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 966 return 0; 967 } 968 return group->meth->point_get_Jprojective_coordinates(group, point, 969 x, y, z, ctx); 970 } 971 972 int 973 EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group, EC_POINT *point, 974 const BIGNUM *x, const BIGNUM *y, const BIGNUM *z, BN_CTX *ctx) 975 { 976 return EC_POINT_set_Jprojective_coordinates(group, point, x, y, z, ctx); 977 } 978 979 int 980 EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group, 981 const EC_POINT *point, BIGNUM *x, BIGNUM *y, BIGNUM *z, BN_CTX *ctx) 982 { 983 return EC_POINT_get_Jprojective_coordinates(group, point, x, y, z, ctx); 984 } 985 986 int 987 EC_POINT_set_affine_coordinates(const EC_GROUP *group, EC_POINT *point, 988 const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx) 989 { 990 if (group->meth->point_set_affine_coordinates == NULL) { 991 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 992 return 0; 993 } 994 if (group->meth != point->meth) { 995 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 996 return 0; 997 } 998 if (!group->meth->point_set_affine_coordinates(group, point, x, y, ctx)) 999 return 0; 1000 if (EC_POINT_is_on_curve(group, point, ctx) <= 0) { 1001 ECerror(EC_R_POINT_IS_NOT_ON_CURVE); 1002 return 0; 1003 } 1004 return 1; 1005 } 1006 1007 int 1008 EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group, EC_POINT *point, 1009 const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx) 1010 { 1011 return EC_POINT_set_affine_coordinates(group, point, x, y, ctx); 1012 } 1013 1014 #ifndef OPENSSL_NO_EC2M 1015 int 1016 EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group, EC_POINT *point, 1017 const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx) 1018 { 1019 return EC_POINT_set_affine_coordinates(group, point, x, y, ctx); 1020 } 1021 #endif 1022 1023 int 1024 EC_POINT_get_affine_coordinates(const EC_GROUP *group, const EC_POINT *point, 1025 BIGNUM *x, BIGNUM *y, BN_CTX *ctx) 1026 { 1027 if (group->meth->point_get_affine_coordinates == NULL) { 1028 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1029 return 0; 1030 } 1031 if (group->meth != point->meth) { 1032 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 1033 return 0; 1034 } 1035 return group->meth->point_get_affine_coordinates(group, point, x, y, ctx); 1036 } 1037 1038 int 1039 EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group, const EC_POINT *point, 1040 BIGNUM *x, BIGNUM *y, BN_CTX *ctx) 1041 { 1042 return EC_POINT_get_affine_coordinates(group, point, x, y, ctx); 1043 } 1044 1045 #ifndef OPENSSL_NO_EC2M 1046 int 1047 EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group, const EC_POINT *point, 1048 BIGNUM *x, BIGNUM *y, BN_CTX *ctx) 1049 { 1050 return EC_POINT_get_affine_coordinates(group, point, x, y, ctx); 1051 } 1052 #endif 1053 1054 int 1055 EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, 1056 const EC_POINT *b, BN_CTX *ctx) 1057 { 1058 if (group->meth->add == 0) { 1059 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1060 return 0; 1061 } 1062 if ((group->meth != r->meth) || (r->meth != a->meth) || (a->meth != b->meth)) { 1063 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 1064 return 0; 1065 } 1066 return group->meth->add(group, r, a, b, ctx); 1067 } 1068 1069 1070 int 1071 EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, BN_CTX *ctx) 1072 { 1073 if (group->meth->dbl == 0) { 1074 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1075 return 0; 1076 } 1077 if ((group->meth != r->meth) || (r->meth != a->meth)) { 1078 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 1079 return 0; 1080 } 1081 return group->meth->dbl(group, r, a, ctx); 1082 } 1083 1084 1085 int 1086 EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx) 1087 { 1088 if (group->meth->invert == 0) { 1089 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1090 return 0; 1091 } 1092 if (group->meth != a->meth) { 1093 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 1094 return 0; 1095 } 1096 return group->meth->invert(group, a, ctx); 1097 } 1098 1099 1100 int 1101 EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *point) 1102 { 1103 if (group->meth->is_at_infinity == 0) { 1104 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1105 return 0; 1106 } 1107 if (group->meth != point->meth) { 1108 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 1109 return 0; 1110 } 1111 return group->meth->is_at_infinity(group, point); 1112 } 1113 1114 1115 int 1116 EC_POINT_is_on_curve(const EC_GROUP * group, const EC_POINT * point, BN_CTX * ctx) 1117 { 1118 if (group->meth->is_on_curve == 0) { 1119 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1120 return 0; 1121 } 1122 if (group->meth != point->meth) { 1123 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 1124 return 0; 1125 } 1126 return group->meth->is_on_curve(group, point, ctx); 1127 } 1128 1129 1130 int 1131 EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b, 1132 BN_CTX * ctx) 1133 { 1134 if (group->meth->point_cmp == 0) { 1135 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1136 return -1; 1137 } 1138 if ((group->meth != a->meth) || (a->meth != b->meth)) { 1139 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 1140 return -1; 1141 } 1142 return group->meth->point_cmp(group, a, b, ctx); 1143 } 1144 1145 1146 int 1147 EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx) 1148 { 1149 if (group->meth->make_affine == 0) { 1150 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1151 return 0; 1152 } 1153 if (group->meth != point->meth) { 1154 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 1155 return 0; 1156 } 1157 return group->meth->make_affine(group, point, ctx); 1158 } 1159 1160 1161 int 1162 EC_POINTs_make_affine(const EC_GROUP *group, size_t num, EC_POINT *points[], 1163 BN_CTX *ctx) 1164 { 1165 size_t i; 1166 1167 if (group->meth->points_make_affine == 0) { 1168 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1169 return 0; 1170 } 1171 for (i = 0; i < num; i++) { 1172 if (group->meth != points[i]->meth) { 1173 ECerror(EC_R_INCOMPATIBLE_OBJECTS); 1174 return 0; 1175 } 1176 } 1177 return group->meth->points_make_affine(group, num, points, ctx); 1178 } 1179 1180 1181 /* Functions for point multiplication */ 1182 int 1183 EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar, 1184 size_t num, const EC_POINT *points[], const BIGNUM *scalars[], BN_CTX *ctx) 1185 { 1186 /* 1187 * The function pointers must be set, and only support num == 0 and 1188 * num == 1. 1189 */ 1190 if (group->meth->mul_generator_ct == NULL || 1191 group->meth->mul_single_ct == NULL || 1192 group->meth->mul_double_nonct == NULL || 1193 num > 1) { 1194 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1195 return 0; 1196 } 1197 1198 /* Either bP or aG + bP, this is sane. */ 1199 if (num == 1 && points != NULL && scalars != NULL) 1200 return EC_POINT_mul(group, r, scalar, points[0], scalars[0], 1201 ctx); 1202 1203 /* aG, this is sane */ 1204 if (scalar != NULL && points == NULL && scalars == NULL) 1205 return EC_POINT_mul(group, r, scalar, NULL, NULL, ctx); 1206 1207 /* anything else is an error */ 1208 ECerror(ERR_R_EC_LIB); 1209 return 0; 1210 } 1211 1212 int 1213 EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar, 1214 const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx) 1215 { 1216 if (group->meth->mul_generator_ct == NULL || 1217 group->meth->mul_single_ct == NULL || 1218 group->meth->mul_double_nonct == NULL) { 1219 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 1220 return 0; 1221 } 1222 if (g_scalar != NULL && point == NULL && p_scalar == NULL) { 1223 /* 1224 * In this case we want to compute g_scalar * GeneratorPoint: 1225 * this codepath is reached most prominently by (ephemeral) key 1226 * generation of EC cryptosystems (i.e. ECDSA keygen and sign 1227 * setup, ECDH keygen/first half), where the scalar is always 1228 * secret. This is why we ignore if BN_FLG_CONSTTIME is actually 1229 * set and we always call the constant time version. 1230 */ 1231 return group->meth->mul_generator_ct(group, r, g_scalar, ctx); 1232 } 1233 if (g_scalar == NULL && point != NULL && p_scalar != NULL) { 1234 /* In this case we want to compute p_scalar * GenericPoint: 1235 * this codepath is reached most prominently by the second half 1236 * of ECDH, where the secret scalar is multiplied by the peer's 1237 * public point. To protect the secret scalar, we ignore if 1238 * BN_FLG_CONSTTIME is actually set and we always call the 1239 * constant time version. 1240 */ 1241 return group->meth->mul_single_ct(group, r, p_scalar, point, 1242 ctx); 1243 } 1244 if (g_scalar != NULL && point != NULL && p_scalar != NULL) { 1245 /* 1246 * In this case we want to compute 1247 * g_scalar * GeneratorPoint + p_scalar * GenericPoint: 1248 * this codepath is reached most prominently by ECDSA signature 1249 * verification. So we call the non-ct version. 1250 */ 1251 return group->meth->mul_double_nonct(group, r, g_scalar, 1252 p_scalar, point, ctx); 1253 } 1254 1255 /* Anything else is an error. */ 1256 ECerror(ERR_R_EC_LIB); 1257 return 0; 1258 } 1259 1260 int 1261 EC_GROUP_precompute_mult(EC_GROUP * group, BN_CTX * ctx) 1262 { 1263 if (group->meth->precompute_mult != 0) 1264 return group->meth->precompute_mult(group, ctx); 1265 else 1266 return 1; /* nothing to do, so report success */ 1267 } 1268 1269 int 1270 EC_GROUP_have_precompute_mult(const EC_GROUP * group) 1271 { 1272 if (group->meth->have_precompute_mult != 0) 1273 return group->meth->have_precompute_mult(group); 1274 else 1275 return 0; /* cannot tell whether precomputation has 1276 * been performed */ 1277 } 1278 1279 int 1280 ec_group_simple_order_bits(const EC_GROUP *group) 1281 { 1282 /* XXX change group->order to a pointer? */ 1283 #if 0 1284 if (group->order == NULL) 1285 return 0; 1286 #endif 1287 return BN_num_bits(&group->order); 1288 } 1289 1290 EC_KEY * 1291 ECParameters_dup(EC_KEY *key) 1292 { 1293 unsigned char *p = NULL; 1294 EC_KEY *k = NULL; 1295 int len; 1296 1297 if (key == NULL) 1298 return (NULL); 1299 1300 if ((len = i2d_ECParameters(key, &p)) > 0) 1301 k = d2i_ECParameters(NULL, (const unsigned char **)&p, len); 1302 1303 return (k); 1304 } 1305