1 /* 2 * Copyright 2002-2018 The OpenSSL Project Authors. All Rights Reserved. 3 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved 4 * 5 * Licensed under the OpenSSL license (the "License"). You may not use 6 * this file except in compliance with the License. You can obtain a copy 7 * in the file LICENSE in the source distribution or at 8 * https://www.openssl.org/source/license.html 9 */ 10 11 #include "internal/cryptlib.h" 12 #include <string.h> 13 #include "ec_lcl.h" 14 #include "internal/refcount.h" 15 #include <openssl/err.h> 16 #include <openssl/engine.h> 17 18 EC_KEY *EC_KEY_new(void) 19 { 20 return EC_KEY_new_method(NULL); 21 } 22 23 EC_KEY *EC_KEY_new_by_curve_name(int nid) 24 { 25 EC_KEY *ret = EC_KEY_new(); 26 if (ret == NULL) 27 return NULL; 28 ret->group = EC_GROUP_new_by_curve_name(nid); 29 if (ret->group == NULL) { 30 EC_KEY_free(ret); 31 return NULL; 32 } 33 if (ret->meth->set_group != NULL 34 && ret->meth->set_group(ret, ret->group) == 0) { 35 EC_KEY_free(ret); 36 return NULL; 37 } 38 return ret; 39 } 40 41 void EC_KEY_free(EC_KEY *r) 42 { 43 int i; 44 45 if (r == NULL) 46 return; 47 48 CRYPTO_DOWN_REF(&r->references, &i, r->lock); 49 REF_PRINT_COUNT("EC_KEY", r); 50 if (i > 0) 51 return; 52 REF_ASSERT_ISNT(i < 0); 53 54 if (r->meth != NULL && r->meth->finish != NULL) 55 r->meth->finish(r); 56 57 #ifndef OPENSSL_NO_ENGINE 58 ENGINE_finish(r->engine); 59 #endif 60 61 if (r->group && r->group->meth->keyfinish) 62 r->group->meth->keyfinish(r); 63 64 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_EC_KEY, r, &r->ex_data); 65 CRYPTO_THREAD_lock_free(r->lock); 66 EC_GROUP_free(r->group); 67 EC_POINT_free(r->pub_key); 68 BN_clear_free(r->priv_key); 69 70 OPENSSL_clear_free((void *)r, sizeof(EC_KEY)); 71 } 72 73 EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src) 74 { 75 if (dest == NULL || src == NULL) { 76 ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER); 77 return NULL; 78 } 79 if (src->meth != dest->meth) { 80 if (dest->meth->finish != NULL) 81 dest->meth->finish(dest); 82 if (dest->group && dest->group->meth->keyfinish) 83 dest->group->meth->keyfinish(dest); 84 #ifndef OPENSSL_NO_ENGINE 85 if (ENGINE_finish(dest->engine) == 0) 86 return 0; 87 dest->engine = NULL; 88 #endif 89 } 90 /* copy the parameters */ 91 if (src->group != NULL) { 92 const EC_METHOD *meth = EC_GROUP_method_of(src->group); 93 /* clear the old group */ 94 EC_GROUP_free(dest->group); 95 dest->group = EC_GROUP_new(meth); 96 if (dest->group == NULL) 97 return NULL; 98 if (!EC_GROUP_copy(dest->group, src->group)) 99 return NULL; 100 101 /* copy the public key */ 102 if (src->pub_key != NULL) { 103 EC_POINT_free(dest->pub_key); 104 dest->pub_key = EC_POINT_new(src->group); 105 if (dest->pub_key == NULL) 106 return NULL; 107 if (!EC_POINT_copy(dest->pub_key, src->pub_key)) 108 return NULL; 109 } 110 /* copy the private key */ 111 if (src->priv_key != NULL) { 112 if (dest->priv_key == NULL) { 113 dest->priv_key = BN_new(); 114 if (dest->priv_key == NULL) 115 return NULL; 116 } 117 if (!BN_copy(dest->priv_key, src->priv_key)) 118 return NULL; 119 if (src->group->meth->keycopy 120 && src->group->meth->keycopy(dest, src) == 0) 121 return NULL; 122 } 123 } 124 125 126 /* copy the rest */ 127 dest->enc_flag = src->enc_flag; 128 dest->conv_form = src->conv_form; 129 dest->version = src->version; 130 dest->flags = src->flags; 131 if (!CRYPTO_dup_ex_data(CRYPTO_EX_INDEX_EC_KEY, 132 &dest->ex_data, &src->ex_data)) 133 return NULL; 134 135 if (src->meth != dest->meth) { 136 #ifndef OPENSSL_NO_ENGINE 137 if (src->engine != NULL && ENGINE_init(src->engine) == 0) 138 return NULL; 139 dest->engine = src->engine; 140 #endif 141 dest->meth = src->meth; 142 } 143 144 if (src->meth->copy != NULL && src->meth->copy(dest, src) == 0) 145 return NULL; 146 147 return dest; 148 } 149 150 EC_KEY *EC_KEY_dup(const EC_KEY *ec_key) 151 { 152 EC_KEY *ret = EC_KEY_new_method(ec_key->engine); 153 154 if (ret == NULL) 155 return NULL; 156 157 if (EC_KEY_copy(ret, ec_key) == NULL) { 158 EC_KEY_free(ret); 159 return NULL; 160 } 161 return ret; 162 } 163 164 int EC_KEY_up_ref(EC_KEY *r) 165 { 166 int i; 167 168 if (CRYPTO_UP_REF(&r->references, &i, r->lock) <= 0) 169 return 0; 170 171 REF_PRINT_COUNT("EC_KEY", r); 172 REF_ASSERT_ISNT(i < 2); 173 return ((i > 1) ? 1 : 0); 174 } 175 176 ENGINE *EC_KEY_get0_engine(const EC_KEY *eckey) 177 { 178 return eckey->engine; 179 } 180 181 int EC_KEY_generate_key(EC_KEY *eckey) 182 { 183 if (eckey == NULL || eckey->group == NULL) { 184 ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER); 185 return 0; 186 } 187 if (eckey->meth->keygen != NULL) 188 return eckey->meth->keygen(eckey); 189 ECerr(EC_F_EC_KEY_GENERATE_KEY, EC_R_OPERATION_NOT_SUPPORTED); 190 return 0; 191 } 192 193 int ossl_ec_key_gen(EC_KEY *eckey) 194 { 195 return eckey->group->meth->keygen(eckey); 196 } 197 198 int ec_key_simple_generate_key(EC_KEY *eckey) 199 { 200 int ok = 0; 201 BN_CTX *ctx = NULL; 202 BIGNUM *priv_key = NULL; 203 const BIGNUM *order = NULL; 204 EC_POINT *pub_key = NULL; 205 206 if ((ctx = BN_CTX_new()) == NULL) 207 goto err; 208 209 if (eckey->priv_key == NULL) { 210 priv_key = BN_new(); 211 if (priv_key == NULL) 212 goto err; 213 } else 214 priv_key = eckey->priv_key; 215 216 order = EC_GROUP_get0_order(eckey->group); 217 if (order == NULL) 218 goto err; 219 220 do 221 if (!BN_priv_rand_range(priv_key, order)) 222 goto err; 223 while (BN_is_zero(priv_key)) ; 224 225 if (eckey->pub_key == NULL) { 226 pub_key = EC_POINT_new(eckey->group); 227 if (pub_key == NULL) 228 goto err; 229 } else 230 pub_key = eckey->pub_key; 231 232 if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx)) 233 goto err; 234 235 eckey->priv_key = priv_key; 236 eckey->pub_key = pub_key; 237 238 ok = 1; 239 240 err: 241 if (eckey->pub_key == NULL) 242 EC_POINT_free(pub_key); 243 if (eckey->priv_key != priv_key) 244 BN_free(priv_key); 245 BN_CTX_free(ctx); 246 return ok; 247 } 248 249 int ec_key_simple_generate_public_key(EC_KEY *eckey) 250 { 251 return EC_POINT_mul(eckey->group, eckey->pub_key, eckey->priv_key, NULL, 252 NULL, NULL); 253 } 254 255 int EC_KEY_check_key(const EC_KEY *eckey) 256 { 257 if (eckey == NULL || eckey->group == NULL || eckey->pub_key == NULL) { 258 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER); 259 return 0; 260 } 261 262 if (eckey->group->meth->keycheck == NULL) { 263 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 264 return 0; 265 } 266 267 return eckey->group->meth->keycheck(eckey); 268 } 269 270 int ec_key_simple_check_key(const EC_KEY *eckey) 271 { 272 int ok = 0; 273 BN_CTX *ctx = NULL; 274 const BIGNUM *order = NULL; 275 EC_POINT *point = NULL; 276 277 if (eckey == NULL || eckey->group == NULL || eckey->pub_key == NULL) { 278 ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER); 279 return 0; 280 } 281 282 if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) { 283 ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_POINT_AT_INFINITY); 284 goto err; 285 } 286 287 if ((ctx = BN_CTX_new()) == NULL) 288 goto err; 289 if ((point = EC_POINT_new(eckey->group)) == NULL) 290 goto err; 291 292 /* testing whether the pub_key is on the elliptic curve */ 293 if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) { 294 ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE); 295 goto err; 296 } 297 /* testing whether pub_key * order is the point at infinity */ 298 order = eckey->group->order; 299 if (BN_is_zero(order)) { 300 ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_INVALID_GROUP_ORDER); 301 goto err; 302 } 303 if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) { 304 ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, ERR_R_EC_LIB); 305 goto err; 306 } 307 if (!EC_POINT_is_at_infinity(eckey->group, point)) { 308 ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_WRONG_ORDER); 309 goto err; 310 } 311 /* 312 * in case the priv_key is present : check if generator * priv_key == 313 * pub_key 314 */ 315 if (eckey->priv_key != NULL) { 316 if (BN_cmp(eckey->priv_key, order) >= 0) { 317 ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_WRONG_ORDER); 318 goto err; 319 } 320 if (!EC_POINT_mul(eckey->group, point, eckey->priv_key, 321 NULL, NULL, ctx)) { 322 ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, ERR_R_EC_LIB); 323 goto err; 324 } 325 if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, ctx) != 0) { 326 ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY); 327 goto err; 328 } 329 } 330 ok = 1; 331 err: 332 BN_CTX_free(ctx); 333 EC_POINT_free(point); 334 return ok; 335 } 336 337 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x, 338 BIGNUM *y) 339 { 340 BN_CTX *ctx = NULL; 341 BIGNUM *tx, *ty; 342 EC_POINT *point = NULL; 343 int ok = 0; 344 345 if (key == NULL || key->group == NULL || x == NULL || y == NULL) { 346 ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES, 347 ERR_R_PASSED_NULL_PARAMETER); 348 return 0; 349 } 350 ctx = BN_CTX_new(); 351 if (ctx == NULL) 352 return 0; 353 354 BN_CTX_start(ctx); 355 point = EC_POINT_new(key->group); 356 357 if (point == NULL) 358 goto err; 359 360 tx = BN_CTX_get(ctx); 361 ty = BN_CTX_get(ctx); 362 if (ty == NULL) 363 goto err; 364 365 if (!EC_POINT_set_affine_coordinates(key->group, point, x, y, ctx)) 366 goto err; 367 if (!EC_POINT_get_affine_coordinates(key->group, point, tx, ty, ctx)) 368 goto err; 369 370 /* 371 * Check if retrieved coordinates match originals and are less than field 372 * order: if not values are out of range. 373 */ 374 if (BN_cmp(x, tx) || BN_cmp(y, ty) 375 || (BN_cmp(x, key->group->field) >= 0) 376 || (BN_cmp(y, key->group->field) >= 0)) { 377 ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES, 378 EC_R_COORDINATES_OUT_OF_RANGE); 379 goto err; 380 } 381 382 if (!EC_KEY_set_public_key(key, point)) 383 goto err; 384 385 if (EC_KEY_check_key(key) == 0) 386 goto err; 387 388 ok = 1; 389 390 err: 391 BN_CTX_end(ctx); 392 BN_CTX_free(ctx); 393 EC_POINT_free(point); 394 return ok; 395 396 } 397 398 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key) 399 { 400 return key->group; 401 } 402 403 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group) 404 { 405 if (key->meth->set_group != NULL && key->meth->set_group(key, group) == 0) 406 return 0; 407 EC_GROUP_free(key->group); 408 key->group = EC_GROUP_dup(group); 409 return (key->group == NULL) ? 0 : 1; 410 } 411 412 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key) 413 { 414 return key->priv_key; 415 } 416 417 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key) 418 { 419 if (key->group == NULL || key->group->meth == NULL) 420 return 0; 421 if (key->group->meth->set_private != NULL 422 && key->group->meth->set_private(key, priv_key) == 0) 423 return 0; 424 if (key->meth->set_private != NULL 425 && key->meth->set_private(key, priv_key) == 0) 426 return 0; 427 BN_clear_free(key->priv_key); 428 key->priv_key = BN_dup(priv_key); 429 return (key->priv_key == NULL) ? 0 : 1; 430 } 431 432 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key) 433 { 434 return key->pub_key; 435 } 436 437 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key) 438 { 439 if (key->meth->set_public != NULL 440 && key->meth->set_public(key, pub_key) == 0) 441 return 0; 442 EC_POINT_free(key->pub_key); 443 key->pub_key = EC_POINT_dup(pub_key, key->group); 444 return (key->pub_key == NULL) ? 0 : 1; 445 } 446 447 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key) 448 { 449 return key->enc_flag; 450 } 451 452 void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags) 453 { 454 key->enc_flag = flags; 455 } 456 457 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key) 458 { 459 return key->conv_form; 460 } 461 462 void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform) 463 { 464 key->conv_form = cform; 465 if (key->group != NULL) 466 EC_GROUP_set_point_conversion_form(key->group, cform); 467 } 468 469 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag) 470 { 471 if (key->group != NULL) 472 EC_GROUP_set_asn1_flag(key->group, flag); 473 } 474 475 int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx) 476 { 477 if (key->group == NULL) 478 return 0; 479 return EC_GROUP_precompute_mult(key->group, ctx); 480 } 481 482 int EC_KEY_get_flags(const EC_KEY *key) 483 { 484 return key->flags; 485 } 486 487 void EC_KEY_set_flags(EC_KEY *key, int flags) 488 { 489 key->flags |= flags; 490 } 491 492 void EC_KEY_clear_flags(EC_KEY *key, int flags) 493 { 494 key->flags &= ~flags; 495 } 496 497 size_t EC_KEY_key2buf(const EC_KEY *key, point_conversion_form_t form, 498 unsigned char **pbuf, BN_CTX *ctx) 499 { 500 if (key == NULL || key->pub_key == NULL || key->group == NULL) 501 return 0; 502 return EC_POINT_point2buf(key->group, key->pub_key, form, pbuf, ctx); 503 } 504 505 int EC_KEY_oct2key(EC_KEY *key, const unsigned char *buf, size_t len, 506 BN_CTX *ctx) 507 { 508 if (key == NULL || key->group == NULL) 509 return 0; 510 if (key->pub_key == NULL) 511 key->pub_key = EC_POINT_new(key->group); 512 if (key->pub_key == NULL) 513 return 0; 514 if (EC_POINT_oct2point(key->group, key->pub_key, buf, len, ctx) == 0) 515 return 0; 516 /* 517 * Save the point conversion form. 518 * For non-custom curves the first octet of the buffer (excluding 519 * the last significant bit) contains the point conversion form. 520 * EC_POINT_oct2point() has already performed sanity checking of 521 * the buffer so we know it is valid. 522 */ 523 if ((key->group->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) 524 key->conv_form = (point_conversion_form_t)(buf[0] & ~0x01); 525 return 1; 526 } 527 528 size_t EC_KEY_priv2oct(const EC_KEY *eckey, 529 unsigned char *buf, size_t len) 530 { 531 if (eckey->group == NULL || eckey->group->meth == NULL) 532 return 0; 533 if (eckey->group->meth->priv2oct == NULL) { 534 ECerr(EC_F_EC_KEY_PRIV2OCT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 535 return 0; 536 } 537 538 return eckey->group->meth->priv2oct(eckey, buf, len); 539 } 540 541 size_t ec_key_simple_priv2oct(const EC_KEY *eckey, 542 unsigned char *buf, size_t len) 543 { 544 size_t buf_len; 545 546 buf_len = (EC_GROUP_order_bits(eckey->group) + 7) / 8; 547 if (eckey->priv_key == NULL) 548 return 0; 549 if (buf == NULL) 550 return buf_len; 551 else if (len < buf_len) 552 return 0; 553 554 /* Octetstring may need leading zeros if BN is to short */ 555 556 if (BN_bn2binpad(eckey->priv_key, buf, buf_len) == -1) { 557 ECerr(EC_F_EC_KEY_SIMPLE_PRIV2OCT, EC_R_BUFFER_TOO_SMALL); 558 return 0; 559 } 560 561 return buf_len; 562 } 563 564 int EC_KEY_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len) 565 { 566 if (eckey->group == NULL || eckey->group->meth == NULL) 567 return 0; 568 if (eckey->group->meth->oct2priv == NULL) { 569 ECerr(EC_F_EC_KEY_OCT2PRIV, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 570 return 0; 571 } 572 return eckey->group->meth->oct2priv(eckey, buf, len); 573 } 574 575 int ec_key_simple_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len) 576 { 577 if (eckey->priv_key == NULL) 578 eckey->priv_key = BN_secure_new(); 579 if (eckey->priv_key == NULL) { 580 ECerr(EC_F_EC_KEY_SIMPLE_OCT2PRIV, ERR_R_MALLOC_FAILURE); 581 return 0; 582 } 583 eckey->priv_key = BN_bin2bn(buf, len, eckey->priv_key); 584 if (eckey->priv_key == NULL) { 585 ECerr(EC_F_EC_KEY_SIMPLE_OCT2PRIV, ERR_R_BN_LIB); 586 return 0; 587 } 588 return 1; 589 } 590 591 size_t EC_KEY_priv2buf(const EC_KEY *eckey, unsigned char **pbuf) 592 { 593 size_t len; 594 unsigned char *buf; 595 596 len = EC_KEY_priv2oct(eckey, NULL, 0); 597 if (len == 0) 598 return 0; 599 if ((buf = OPENSSL_malloc(len)) == NULL) { 600 ECerr(EC_F_EC_KEY_PRIV2BUF, ERR_R_MALLOC_FAILURE); 601 return 0; 602 } 603 len = EC_KEY_priv2oct(eckey, buf, len); 604 if (len == 0) { 605 OPENSSL_free(buf); 606 return 0; 607 } 608 *pbuf = buf; 609 return len; 610 } 611 612 int EC_KEY_can_sign(const EC_KEY *eckey) 613 { 614 if (eckey->group == NULL || eckey->group->meth == NULL 615 || (eckey->group->meth->flags & EC_FLAGS_NO_SIGN)) 616 return 0; 617 return 1; 618 } 619