1 /* $OpenBSD: ec_key.c,v 1.22 2018/11/09 23:39:45 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 "bn_lcl.h" 69 #include "ec_lcl.h" 70 #include <openssl/err.h> 71 72 EC_KEY * 73 EC_KEY_new(void) 74 { 75 EC_KEY *ret; 76 77 ret = malloc(sizeof(EC_KEY)); 78 if (ret == NULL) { 79 ECerror(ERR_R_MALLOC_FAILURE); 80 return (NULL); 81 } 82 ret->version = 1; 83 ret->flags = 0; 84 ret->group = NULL; 85 ret->pub_key = NULL; 86 ret->priv_key = NULL; 87 ret->enc_flag = 0; 88 ret->conv_form = POINT_CONVERSION_UNCOMPRESSED; 89 ret->references = 1; 90 ret->method_data = NULL; 91 return (ret); 92 } 93 94 EC_KEY * 95 EC_KEY_new_by_curve_name(int nid) 96 { 97 EC_KEY *ret = EC_KEY_new(); 98 if (ret == NULL) 99 return NULL; 100 ret->group = EC_GROUP_new_by_curve_name(nid); 101 if (ret->group == NULL) { 102 EC_KEY_free(ret); 103 return NULL; 104 } 105 return ret; 106 } 107 108 void 109 EC_KEY_free(EC_KEY * r) 110 { 111 int i; 112 113 if (r == NULL) 114 return; 115 116 i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_EC); 117 if (i > 0) 118 return; 119 120 EC_GROUP_free(r->group); 121 EC_POINT_free(r->pub_key); 122 BN_clear_free(r->priv_key); 123 124 EC_EX_DATA_free_all_data(&r->method_data); 125 126 freezero(r, sizeof(EC_KEY)); 127 } 128 129 EC_KEY * 130 EC_KEY_copy(EC_KEY * dest, const EC_KEY * src) 131 { 132 EC_EXTRA_DATA *d; 133 134 if (dest == NULL || src == NULL) { 135 ECerror(ERR_R_PASSED_NULL_PARAMETER); 136 return NULL; 137 } 138 /* copy the parameters */ 139 if (src->group) { 140 const EC_METHOD *meth = EC_GROUP_method_of(src->group); 141 /* clear the old group */ 142 EC_GROUP_free(dest->group); 143 dest->group = EC_GROUP_new(meth); 144 if (dest->group == NULL) 145 return NULL; 146 if (!EC_GROUP_copy(dest->group, src->group)) 147 return NULL; 148 } 149 /* copy the public key */ 150 if (src->pub_key && src->group) { 151 EC_POINT_free(dest->pub_key); 152 dest->pub_key = EC_POINT_new(src->group); 153 if (dest->pub_key == NULL) 154 return NULL; 155 if (!EC_POINT_copy(dest->pub_key, src->pub_key)) 156 return NULL; 157 } 158 /* copy the private key */ 159 if (src->priv_key) { 160 if (dest->priv_key == NULL) { 161 dest->priv_key = BN_new(); 162 if (dest->priv_key == NULL) 163 return NULL; 164 } 165 if (!BN_copy(dest->priv_key, src->priv_key)) 166 return NULL; 167 } 168 /* copy method/extra data */ 169 EC_EX_DATA_free_all_data(&dest->method_data); 170 171 for (d = src->method_data; d != NULL; d = d->next) { 172 void *t = d->dup_func(d->data); 173 174 if (t == NULL) 175 return 0; 176 if (!EC_EX_DATA_set_data(&dest->method_data, t, d->dup_func, 177 d->free_func, d->clear_free_func)) 178 return 0; 179 } 180 181 /* copy the rest */ 182 dest->enc_flag = src->enc_flag; 183 dest->conv_form = src->conv_form; 184 dest->version = src->version; 185 dest->flags = src->flags; 186 187 return dest; 188 } 189 190 EC_KEY * 191 EC_KEY_dup(const EC_KEY * ec_key) 192 { 193 EC_KEY *ret = EC_KEY_new(); 194 if (ret == NULL) 195 return NULL; 196 if (EC_KEY_copy(ret, ec_key) == NULL) { 197 EC_KEY_free(ret); 198 return NULL; 199 } 200 return ret; 201 } 202 203 int 204 EC_KEY_up_ref(EC_KEY * r) 205 { 206 int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC); 207 return ((i > 1) ? 1 : 0); 208 } 209 210 int 211 EC_KEY_generate_key(EC_KEY *eckey) 212 { 213 int ok = 0; 214 BN_CTX *ctx = NULL; 215 BIGNUM *priv_key = NULL, *order = NULL; 216 EC_POINT *pub_key = NULL; 217 218 if (!eckey || !eckey->group) { 219 ECerror(ERR_R_PASSED_NULL_PARAMETER); 220 return 0; 221 } 222 223 if ((order = BN_new()) == NULL) 224 goto err; 225 if ((ctx = BN_CTX_new()) == NULL) 226 goto err; 227 228 if ((priv_key = eckey->priv_key) == NULL) { 229 if ((priv_key = BN_new()) == NULL) 230 goto err; 231 } 232 233 if (!EC_GROUP_get_order(eckey->group, order, ctx)) 234 goto err; 235 236 if (!bn_rand_interval(priv_key, BN_value_one(), order)) 237 goto err; 238 239 if ((pub_key = eckey->pub_key) == NULL) { 240 if ((pub_key = EC_POINT_new(eckey->group)) == NULL) 241 goto err; 242 } 243 244 if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx)) 245 goto err; 246 247 eckey->priv_key = priv_key; 248 eckey->pub_key = pub_key; 249 250 ok = 1; 251 252 err: 253 BN_free(order); 254 if (eckey->pub_key == NULL) 255 EC_POINT_free(pub_key); 256 if (eckey->priv_key == NULL) 257 BN_free(priv_key); 258 BN_CTX_free(ctx); 259 return (ok); 260 } 261 262 int 263 EC_KEY_check_key(const EC_KEY * eckey) 264 { 265 int ok = 0; 266 BN_CTX *ctx = NULL; 267 const BIGNUM *order = NULL; 268 EC_POINT *point = NULL; 269 270 if (!eckey || !eckey->group || !eckey->pub_key) { 271 ECerror(ERR_R_PASSED_NULL_PARAMETER); 272 return 0; 273 } 274 if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key) > 0) { 275 ECerror(EC_R_POINT_AT_INFINITY); 276 goto err; 277 } 278 if ((ctx = BN_CTX_new()) == NULL) 279 goto err; 280 if ((point = EC_POINT_new(eckey->group)) == NULL) 281 goto err; 282 283 /* testing whether the pub_key is on the elliptic curve */ 284 if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) { 285 ECerror(EC_R_POINT_IS_NOT_ON_CURVE); 286 goto err; 287 } 288 /* testing whether pub_key * order is the point at infinity */ 289 order = &eckey->group->order; 290 if (BN_is_zero(order)) { 291 ECerror(EC_R_INVALID_GROUP_ORDER); 292 goto err; 293 } 294 if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) { 295 ECerror(ERR_R_EC_LIB); 296 goto err; 297 } 298 if (EC_POINT_is_at_infinity(eckey->group, point) <= 0) { 299 ECerror(EC_R_WRONG_ORDER); 300 goto err; 301 } 302 /* 303 * in case the priv_key is present : check if generator * priv_key == 304 * pub_key 305 */ 306 if (eckey->priv_key) { 307 if (BN_cmp(eckey->priv_key, order) >= 0) { 308 ECerror(EC_R_WRONG_ORDER); 309 goto err; 310 } 311 if (!EC_POINT_mul(eckey->group, point, eckey->priv_key, 312 NULL, NULL, ctx)) { 313 ECerror(ERR_R_EC_LIB); 314 goto err; 315 } 316 if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, 317 ctx) != 0) { 318 ECerror(EC_R_INVALID_PRIVATE_KEY); 319 goto err; 320 } 321 } 322 ok = 1; 323 err: 324 BN_CTX_free(ctx); 325 EC_POINT_free(point); 326 return (ok); 327 } 328 329 int 330 EC_KEY_set_public_key_affine_coordinates(EC_KEY * key, BIGNUM * x, BIGNUM * y) 331 { 332 BN_CTX *ctx = NULL; 333 BIGNUM *tx, *ty; 334 EC_POINT *point = NULL; 335 int ok = 0, tmp_nid, is_char_two = 0; 336 337 if (!key || !key->group || !x || !y) { 338 ECerror(ERR_R_PASSED_NULL_PARAMETER); 339 return 0; 340 } 341 ctx = BN_CTX_new(); 342 if (!ctx) 343 goto err; 344 345 point = EC_POINT_new(key->group); 346 347 if (!point) 348 goto err; 349 350 tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group)); 351 352 if (tmp_nid == NID_X9_62_characteristic_two_field) 353 is_char_two = 1; 354 355 if ((tx = BN_CTX_get(ctx)) == NULL) 356 goto err; 357 if ((ty = BN_CTX_get(ctx)) == NULL) 358 goto err; 359 360 #ifndef OPENSSL_NO_EC2M 361 if (is_char_two) { 362 if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point, 363 x, y, ctx)) 364 goto err; 365 if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point, 366 tx, ty, ctx)) 367 goto err; 368 } else 369 #endif 370 { 371 if (!EC_POINT_set_affine_coordinates_GFp(key->group, point, 372 x, y, ctx)) 373 goto err; 374 if (!EC_POINT_get_affine_coordinates_GFp(key->group, point, 375 tx, ty, ctx)) 376 goto err; 377 } 378 /* 379 * Check if retrieved coordinates match originals: if not values are 380 * out of range. 381 */ 382 if (BN_cmp(x, tx) || BN_cmp(y, ty)) { 383 ECerror(EC_R_COORDINATES_OUT_OF_RANGE); 384 goto err; 385 } 386 if (!EC_KEY_set_public_key(key, point)) 387 goto err; 388 389 if (EC_KEY_check_key(key) == 0) 390 goto err; 391 392 ok = 1; 393 394 err: 395 BN_CTX_free(ctx); 396 EC_POINT_free(point); 397 return ok; 398 399 } 400 401 const EC_GROUP * 402 EC_KEY_get0_group(const EC_KEY * key) 403 { 404 return key->group; 405 } 406 407 int 408 EC_KEY_set_group(EC_KEY * key, const EC_GROUP * group) 409 { 410 EC_GROUP_free(key->group); 411 key->group = EC_GROUP_dup(group); 412 return (key->group == NULL) ? 0 : 1; 413 } 414 415 const BIGNUM * 416 EC_KEY_get0_private_key(const EC_KEY * key) 417 { 418 return key->priv_key; 419 } 420 421 int 422 EC_KEY_set_private_key(EC_KEY * key, const BIGNUM * priv_key) 423 { 424 BN_clear_free(key->priv_key); 425 key->priv_key = BN_dup(priv_key); 426 return (key->priv_key == NULL) ? 0 : 1; 427 } 428 429 const EC_POINT * 430 EC_KEY_get0_public_key(const EC_KEY * key) 431 { 432 return key->pub_key; 433 } 434 435 int 436 EC_KEY_set_public_key(EC_KEY * key, const EC_POINT * pub_key) 437 { 438 EC_POINT_free(key->pub_key); 439 key->pub_key = EC_POINT_dup(pub_key, key->group); 440 return (key->pub_key == NULL) ? 0 : 1; 441 } 442 443 unsigned int 444 EC_KEY_get_enc_flags(const EC_KEY * key) 445 { 446 return key->enc_flag; 447 } 448 449 void 450 EC_KEY_set_enc_flags(EC_KEY * key, unsigned int flags) 451 { 452 key->enc_flag = flags; 453 } 454 455 point_conversion_form_t 456 EC_KEY_get_conv_form(const EC_KEY * key) 457 { 458 return key->conv_form; 459 } 460 461 void 462 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 * 470 EC_KEY_get_key_method_data(EC_KEY *key, 471 void *(*dup_func) (void *), 472 void (*free_func) (void *), 473 void (*clear_free_func) (void *)) 474 { 475 void *ret; 476 477 CRYPTO_r_lock(CRYPTO_LOCK_EC); 478 ret = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func); 479 CRYPTO_r_unlock(CRYPTO_LOCK_EC); 480 481 return ret; 482 } 483 484 void * 485 EC_KEY_insert_key_method_data(EC_KEY * key, void *data, 486 void *(*dup_func) (void *), 487 void (*free_func) (void *), 488 void (*clear_free_func) (void *)) 489 { 490 EC_EXTRA_DATA *ex_data; 491 492 CRYPTO_w_lock(CRYPTO_LOCK_EC); 493 ex_data = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func); 494 if (ex_data == NULL) 495 EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func, clear_free_func); 496 CRYPTO_w_unlock(CRYPTO_LOCK_EC); 497 498 return ex_data; 499 } 500 501 void 502 EC_KEY_set_asn1_flag(EC_KEY * key, int flag) 503 { 504 if (key->group != NULL) 505 EC_GROUP_set_asn1_flag(key->group, flag); 506 } 507 508 int 509 EC_KEY_precompute_mult(EC_KEY * key, BN_CTX * ctx) 510 { 511 if (key->group == NULL) 512 return 0; 513 return EC_GROUP_precompute_mult(key->group, ctx); 514 } 515 516 int 517 EC_KEY_get_flags(const EC_KEY * key) 518 { 519 return key->flags; 520 } 521 522 void 523 EC_KEY_set_flags(EC_KEY * key, int flags) 524 { 525 key->flags |= flags; 526 } 527 528 void 529 EC_KEY_clear_flags(EC_KEY * key, int flags) 530 { 531 key->flags &= ~flags; 532 } 533