1 /* $OpenBSD: ec_key.c,v 1.17 2018/07/15 16:27:39 tb Exp $ */ 2 /* 3 * Written by Nils Larsch for the OpenSSL project. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 1998-2005 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 * Portions originally developed by SUN MICROSYSTEMS, INC., and 61 * contributed to the OpenSSL project. 62 */ 63 64 #include <string.h> 65 66 #include <openssl/opensslconf.h> 67 68 #include "ec_lcl.h" 69 #include <openssl/err.h> 70 71 EC_KEY * 72 EC_KEY_new(void) 73 { 74 EC_KEY *ret; 75 76 ret = malloc(sizeof(EC_KEY)); 77 if (ret == NULL) { 78 ECerror(ERR_R_MALLOC_FAILURE); 79 return (NULL); 80 } 81 ret->version = 1; 82 ret->flags = 0; 83 ret->group = NULL; 84 ret->pub_key = NULL; 85 ret->priv_key = NULL; 86 ret->enc_flag = 0; 87 ret->conv_form = POINT_CONVERSION_UNCOMPRESSED; 88 ret->references = 1; 89 ret->method_data = NULL; 90 return (ret); 91 } 92 93 EC_KEY * 94 EC_KEY_new_by_curve_name(int nid) 95 { 96 EC_KEY *ret = EC_KEY_new(); 97 if (ret == NULL) 98 return NULL; 99 ret->group = EC_GROUP_new_by_curve_name(nid); 100 if (ret->group == NULL) { 101 EC_KEY_free(ret); 102 return NULL; 103 } 104 return ret; 105 } 106 107 void 108 EC_KEY_free(EC_KEY * r) 109 { 110 int i; 111 112 if (r == NULL) 113 return; 114 115 i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_EC); 116 if (i > 0) 117 return; 118 119 EC_GROUP_free(r->group); 120 EC_POINT_free(r->pub_key); 121 BN_clear_free(r->priv_key); 122 123 EC_EX_DATA_free_all_data(&r->method_data); 124 125 freezero(r, sizeof(EC_KEY)); 126 } 127 128 EC_KEY * 129 EC_KEY_copy(EC_KEY * dest, const EC_KEY * src) 130 { 131 EC_EXTRA_DATA *d; 132 133 if (dest == NULL || src == NULL) { 134 ECerror(ERR_R_PASSED_NULL_PARAMETER); 135 return NULL; 136 } 137 /* copy the parameters */ 138 if (src->group) { 139 const EC_METHOD *meth = EC_GROUP_method_of(src->group); 140 /* clear the old group */ 141 EC_GROUP_free(dest->group); 142 dest->group = EC_GROUP_new(meth); 143 if (dest->group == NULL) 144 return NULL; 145 if (!EC_GROUP_copy(dest->group, src->group)) 146 return NULL; 147 } 148 /* copy the public key */ 149 if (src->pub_key && src->group) { 150 EC_POINT_free(dest->pub_key); 151 dest->pub_key = EC_POINT_new(src->group); 152 if (dest->pub_key == NULL) 153 return NULL; 154 if (!EC_POINT_copy(dest->pub_key, src->pub_key)) 155 return NULL; 156 } 157 /* copy the private key */ 158 if (src->priv_key) { 159 if (dest->priv_key == NULL) { 160 dest->priv_key = BN_new(); 161 if (dest->priv_key == NULL) 162 return NULL; 163 } 164 if (!BN_copy(dest->priv_key, src->priv_key)) 165 return NULL; 166 } 167 /* copy method/extra data */ 168 EC_EX_DATA_free_all_data(&dest->method_data); 169 170 for (d = src->method_data; d != NULL; d = d->next) { 171 void *t = d->dup_func(d->data); 172 173 if (t == NULL) 174 return 0; 175 if (!EC_EX_DATA_set_data(&dest->method_data, t, d->dup_func, 176 d->free_func, d->clear_free_func)) 177 return 0; 178 } 179 180 /* copy the rest */ 181 dest->enc_flag = src->enc_flag; 182 dest->conv_form = src->conv_form; 183 dest->version = src->version; 184 dest->flags = src->flags; 185 186 return dest; 187 } 188 189 EC_KEY * 190 EC_KEY_dup(const EC_KEY * ec_key) 191 { 192 EC_KEY *ret = EC_KEY_new(); 193 if (ret == NULL) 194 return NULL; 195 if (EC_KEY_copy(ret, ec_key) == NULL) { 196 EC_KEY_free(ret); 197 return NULL; 198 } 199 return ret; 200 } 201 202 int 203 EC_KEY_up_ref(EC_KEY * r) 204 { 205 int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC); 206 return ((i > 1) ? 1 : 0); 207 } 208 209 int 210 EC_KEY_generate_key(EC_KEY * eckey) 211 { 212 int ok = 0; 213 BN_CTX *ctx = NULL; 214 BIGNUM *priv_key = NULL, *order = NULL; 215 EC_POINT *pub_key = NULL; 216 217 if (!eckey || !eckey->group) { 218 ECerror(ERR_R_PASSED_NULL_PARAMETER); 219 return 0; 220 } 221 if ((order = BN_new()) == NULL) 222 goto err; 223 if ((ctx = BN_CTX_new()) == NULL) 224 goto err; 225 226 if (eckey->priv_key == NULL) { 227 priv_key = BN_new(); 228 if (priv_key == NULL) 229 goto err; 230 } else 231 priv_key = eckey->priv_key; 232 233 if (!EC_GROUP_get_order(eckey->group, order, ctx)) 234 goto err; 235 236 do 237 if (!BN_rand_range(priv_key, order)) 238 goto err; 239 while (BN_is_zero(priv_key)); 240 241 if (eckey->pub_key == NULL) { 242 pub_key = EC_POINT_new(eckey->group); 243 if (pub_key == NULL) 244 goto err; 245 } else 246 pub_key = eckey->pub_key; 247 248 if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx)) 249 goto err; 250 251 eckey->priv_key = priv_key; 252 eckey->pub_key = pub_key; 253 254 ok = 1; 255 256 err: 257 BN_free(order); 258 if (pub_key != NULL && eckey->pub_key == NULL) 259 EC_POINT_free(pub_key); 260 if (priv_key != NULL && eckey->priv_key == NULL) 261 BN_free(priv_key); 262 BN_CTX_free(ctx); 263 return (ok); 264 } 265 266 int 267 EC_KEY_check_key(const EC_KEY * eckey) 268 { 269 int ok = 0; 270 BN_CTX *ctx = NULL; 271 const BIGNUM *order = NULL; 272 EC_POINT *point = NULL; 273 274 if (!eckey || !eckey->group || !eckey->pub_key) { 275 ECerror(ERR_R_PASSED_NULL_PARAMETER); 276 return 0; 277 } 278 if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key) > 0) { 279 ECerror(EC_R_POINT_AT_INFINITY); 280 goto err; 281 } 282 if ((ctx = BN_CTX_new()) == NULL) 283 goto err; 284 if ((point = EC_POINT_new(eckey->group)) == NULL) 285 goto err; 286 287 /* testing whether the pub_key is on the elliptic curve */ 288 if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) { 289 ECerror(EC_R_POINT_IS_NOT_ON_CURVE); 290 goto err; 291 } 292 /* testing whether pub_key * order is the point at infinity */ 293 order = &eckey->group->order; 294 if (BN_is_zero(order)) { 295 ECerror(EC_R_INVALID_GROUP_ORDER); 296 goto err; 297 } 298 if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) { 299 ECerror(ERR_R_EC_LIB); 300 goto err; 301 } 302 if (EC_POINT_is_at_infinity(eckey->group, point) <= 0) { 303 ECerror(EC_R_WRONG_ORDER); 304 goto err; 305 } 306 /* 307 * in case the priv_key is present : check if generator * priv_key == 308 * pub_key 309 */ 310 if (eckey->priv_key) { 311 if (BN_cmp(eckey->priv_key, order) >= 0) { 312 ECerror(EC_R_WRONG_ORDER); 313 goto err; 314 } 315 if (!EC_POINT_mul(eckey->group, point, eckey->priv_key, 316 NULL, NULL, ctx)) { 317 ECerror(ERR_R_EC_LIB); 318 goto err; 319 } 320 if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, 321 ctx) != 0) { 322 ECerror(EC_R_INVALID_PRIVATE_KEY); 323 goto err; 324 } 325 } 326 ok = 1; 327 err: 328 BN_CTX_free(ctx); 329 EC_POINT_free(point); 330 return (ok); 331 } 332 333 int 334 EC_KEY_set_public_key_affine_coordinates(EC_KEY * key, BIGNUM * x, BIGNUM * y) 335 { 336 BN_CTX *ctx = NULL; 337 BIGNUM *tx, *ty; 338 EC_POINT *point = NULL; 339 int ok = 0, tmp_nid, is_char_two = 0; 340 341 if (!key || !key->group || !x || !y) { 342 ECerror(ERR_R_PASSED_NULL_PARAMETER); 343 return 0; 344 } 345 ctx = BN_CTX_new(); 346 if (!ctx) 347 goto err; 348 349 point = EC_POINT_new(key->group); 350 351 if (!point) 352 goto err; 353 354 tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group)); 355 356 if (tmp_nid == NID_X9_62_characteristic_two_field) 357 is_char_two = 1; 358 359 if ((tx = BN_CTX_get(ctx)) == NULL) 360 goto err; 361 if ((ty = BN_CTX_get(ctx)) == NULL) 362 goto err; 363 364 #ifndef OPENSSL_NO_EC2M 365 if (is_char_two) { 366 if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point, 367 x, y, ctx)) 368 goto err; 369 if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point, 370 tx, ty, ctx)) 371 goto err; 372 } else 373 #endif 374 { 375 if (!EC_POINT_set_affine_coordinates_GFp(key->group, point, 376 x, y, ctx)) 377 goto err; 378 if (!EC_POINT_get_affine_coordinates_GFp(key->group, point, 379 tx, ty, ctx)) 380 goto err; 381 } 382 /* 383 * Check if retrieved coordinates match originals: if not values are 384 * out of range. 385 */ 386 if (BN_cmp(x, tx) || BN_cmp(y, ty)) { 387 ECerror(EC_R_COORDINATES_OUT_OF_RANGE); 388 goto err; 389 } 390 if (!EC_KEY_set_public_key(key, point)) 391 goto err; 392 393 if (EC_KEY_check_key(key) == 0) 394 goto err; 395 396 ok = 1; 397 398 err: 399 BN_CTX_free(ctx); 400 EC_POINT_free(point); 401 return ok; 402 403 } 404 405 const EC_GROUP * 406 EC_KEY_get0_group(const EC_KEY * key) 407 { 408 return key->group; 409 } 410 411 int 412 EC_KEY_set_group(EC_KEY * key, const EC_GROUP * group) 413 { 414 EC_GROUP_free(key->group); 415 key->group = EC_GROUP_dup(group); 416 return (key->group == NULL) ? 0 : 1; 417 } 418 419 const BIGNUM * 420 EC_KEY_get0_private_key(const EC_KEY * key) 421 { 422 return key->priv_key; 423 } 424 425 int 426 EC_KEY_set_private_key(EC_KEY * key, const BIGNUM * priv_key) 427 { 428 BN_clear_free(key->priv_key); 429 key->priv_key = BN_dup(priv_key); 430 return (key->priv_key == NULL) ? 0 : 1; 431 } 432 433 const EC_POINT * 434 EC_KEY_get0_public_key(const EC_KEY * key) 435 { 436 return key->pub_key; 437 } 438 439 int 440 EC_KEY_set_public_key(EC_KEY * key, const EC_POINT * pub_key) 441 { 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 448 EC_KEY_get_enc_flags(const EC_KEY * key) 449 { 450 return key->enc_flag; 451 } 452 453 void 454 EC_KEY_set_enc_flags(EC_KEY * key, unsigned int flags) 455 { 456 key->enc_flag = flags; 457 } 458 459 point_conversion_form_t 460 EC_KEY_get_conv_form(const EC_KEY * key) 461 { 462 return key->conv_form; 463 } 464 465 void 466 EC_KEY_set_conv_form(EC_KEY * key, point_conversion_form_t cform) 467 { 468 key->conv_form = cform; 469 if (key->group != NULL) 470 EC_GROUP_set_point_conversion_form(key->group, cform); 471 } 472 473 void * 474 EC_KEY_get_key_method_data(EC_KEY *key, 475 void *(*dup_func) (void *), 476 void (*free_func) (void *), 477 void (*clear_free_func) (void *)) 478 { 479 void *ret; 480 481 CRYPTO_r_lock(CRYPTO_LOCK_EC); 482 ret = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func); 483 CRYPTO_r_unlock(CRYPTO_LOCK_EC); 484 485 return ret; 486 } 487 488 void * 489 EC_KEY_insert_key_method_data(EC_KEY * key, void *data, 490 void *(*dup_func) (void *), 491 void (*free_func) (void *), 492 void (*clear_free_func) (void *)) 493 { 494 EC_EXTRA_DATA *ex_data; 495 496 CRYPTO_w_lock(CRYPTO_LOCK_EC); 497 ex_data = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func); 498 if (ex_data == NULL) 499 EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func, clear_free_func); 500 CRYPTO_w_unlock(CRYPTO_LOCK_EC); 501 502 return ex_data; 503 } 504 505 void 506 EC_KEY_set_asn1_flag(EC_KEY * key, int flag) 507 { 508 if (key->group != NULL) 509 EC_GROUP_set_asn1_flag(key->group, flag); 510 } 511 512 int 513 EC_KEY_precompute_mult(EC_KEY * key, BN_CTX * ctx) 514 { 515 if (key->group == NULL) 516 return 0; 517 return EC_GROUP_precompute_mult(key->group, ctx); 518 } 519 520 int 521 EC_KEY_get_flags(const EC_KEY * key) 522 { 523 return key->flags; 524 } 525 526 void 527 EC_KEY_set_flags(EC_KEY * key, int flags) 528 { 529 key->flags |= flags; 530 } 531 532 void 533 EC_KEY_clear_flags(EC_KEY * key, int flags) 534 { 535 key->flags &= ~flags; 536 } 537