1 /* $OpenBSD: ec_key.c,v 1.11 2015/02/09 15:49:22 jsing 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 ECerr(EC_F_EC_KEY_NEW, 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 OPENSSL_cleanse((void *) r, sizeof(EC_KEY)); 126 127 free(r); 128 } 129 130 EC_KEY * 131 EC_KEY_copy(EC_KEY * dest, const EC_KEY * src) 132 { 133 EC_EXTRA_DATA *d; 134 135 if (dest == NULL || src == NULL) { 136 ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER); 137 return NULL; 138 } 139 /* copy the parameters */ 140 if (src->group) { 141 const EC_METHOD *meth = EC_GROUP_method_of(src->group); 142 /* clear the old group */ 143 EC_GROUP_free(dest->group); 144 dest->group = EC_GROUP_new(meth); 145 if (dest->group == NULL) 146 return NULL; 147 if (!EC_GROUP_copy(dest->group, src->group)) 148 return NULL; 149 } 150 /* copy the public key */ 151 if (src->pub_key && src->group) { 152 EC_POINT_free(dest->pub_key); 153 dest->pub_key = EC_POINT_new(src->group); 154 if (dest->pub_key == NULL) 155 return NULL; 156 if (!EC_POINT_copy(dest->pub_key, src->pub_key)) 157 return NULL; 158 } 159 /* copy the private key */ 160 if (src->priv_key) { 161 if (dest->priv_key == NULL) { 162 dest->priv_key = BN_new(); 163 if (dest->priv_key == NULL) 164 return NULL; 165 } 166 if (!BN_copy(dest->priv_key, src->priv_key)) 167 return NULL; 168 } 169 /* copy method/extra data */ 170 EC_EX_DATA_free_all_data(&dest->method_data); 171 172 for (d = src->method_data; d != NULL; d = d->next) { 173 void *t = d->dup_func(d->data); 174 175 if (t == NULL) 176 return 0; 177 if (!EC_EX_DATA_set_data(&dest->method_data, t, d->dup_func, 178 d->free_func, d->clear_free_func)) 179 return 0; 180 } 181 182 /* copy the rest */ 183 dest->enc_flag = src->enc_flag; 184 dest->conv_form = src->conv_form; 185 dest->version = src->version; 186 dest->flags = src->flags; 187 188 return dest; 189 } 190 191 EC_KEY * 192 EC_KEY_dup(const EC_KEY * ec_key) 193 { 194 EC_KEY *ret = EC_KEY_new(); 195 if (ret == NULL) 196 return NULL; 197 if (EC_KEY_copy(ret, ec_key) == NULL) { 198 EC_KEY_free(ret); 199 return NULL; 200 } 201 return ret; 202 } 203 204 int 205 EC_KEY_up_ref(EC_KEY * r) 206 { 207 int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC); 208 return ((i > 1) ? 1 : 0); 209 } 210 211 int 212 EC_KEY_generate_key(EC_KEY * eckey) 213 { 214 int ok = 0; 215 BN_CTX *ctx = NULL; 216 BIGNUM *priv_key = NULL, *order = NULL; 217 EC_POINT *pub_key = NULL; 218 219 if (!eckey || !eckey->group) { 220 ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER); 221 return 0; 222 } 223 if ((order = BN_new()) == NULL) 224 goto err; 225 if ((ctx = BN_CTX_new()) == NULL) 226 goto err; 227 228 if (eckey->priv_key == NULL) { 229 priv_key = BN_new(); 230 if (priv_key == NULL) 231 goto err; 232 } else 233 priv_key = eckey->priv_key; 234 235 if (!EC_GROUP_get_order(eckey->group, order, ctx)) 236 goto err; 237 238 do 239 if (!BN_rand_range(priv_key, order)) 240 goto err; 241 while (BN_is_zero(priv_key)); 242 243 if (eckey->pub_key == NULL) { 244 pub_key = EC_POINT_new(eckey->group); 245 if (pub_key == NULL) 246 goto err; 247 } else 248 pub_key = eckey->pub_key; 249 250 if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx)) 251 goto err; 252 253 eckey->priv_key = priv_key; 254 eckey->pub_key = pub_key; 255 256 ok = 1; 257 258 err: 259 BN_free(order); 260 if (pub_key != NULL && eckey->pub_key == NULL) 261 EC_POINT_free(pub_key); 262 if (priv_key != NULL && eckey->priv_key == NULL) 263 BN_free(priv_key); 264 BN_CTX_free(ctx); 265 return (ok); 266 } 267 268 int 269 EC_KEY_check_key(const EC_KEY * eckey) 270 { 271 int ok = 0; 272 BN_CTX *ctx = NULL; 273 const BIGNUM *order = NULL; 274 EC_POINT *point = NULL; 275 276 if (!eckey || !eckey->group || !eckey->pub_key) { 277 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER); 278 return 0; 279 } 280 if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key) > 0) { 281 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_AT_INFINITY); 282 goto err; 283 } 284 if ((ctx = BN_CTX_new()) == NULL) 285 goto err; 286 if ((point = EC_POINT_new(eckey->group)) == NULL) 287 goto err; 288 289 /* testing whether the pub_key is on the elliptic curve */ 290 if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) { 291 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE); 292 goto err; 293 } 294 /* testing whether pub_key * order is the point at infinity */ 295 order = &eckey->group->order; 296 if (BN_is_zero(order)) { 297 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_GROUP_ORDER); 298 goto err; 299 } 300 if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) { 301 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB); 302 goto err; 303 } 304 if (EC_POINT_is_at_infinity(eckey->group, point) <= 0) { 305 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER); 306 goto err; 307 } 308 /* 309 * in case the priv_key is present : check if generator * priv_key == 310 * pub_key 311 */ 312 if (eckey->priv_key) { 313 if (BN_cmp(eckey->priv_key, order) >= 0) { 314 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER); 315 goto err; 316 } 317 if (!EC_POINT_mul(eckey->group, point, eckey->priv_key, 318 NULL, NULL, ctx)) { 319 ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB); 320 goto err; 321 } 322 if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, 323 ctx) != 0) { 324 ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY); 325 goto err; 326 } 327 } 328 ok = 1; 329 err: 330 BN_CTX_free(ctx); 331 EC_POINT_free(point); 332 return (ok); 333 } 334 335 int 336 EC_KEY_set_public_key_affine_coordinates(EC_KEY * key, BIGNUM * x, BIGNUM * y) 337 { 338 BN_CTX *ctx = NULL; 339 BIGNUM *tx, *ty; 340 EC_POINT *point = NULL; 341 int ok = 0, tmp_nid, is_char_two = 0; 342 343 if (!key || !key->group || !x || !y) { 344 ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES, 345 ERR_R_PASSED_NULL_PARAMETER); 346 return 0; 347 } 348 ctx = BN_CTX_new(); 349 if (!ctx) 350 goto err; 351 352 point = EC_POINT_new(key->group); 353 354 if (!point) 355 goto err; 356 357 tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group)); 358 359 if (tmp_nid == NID_X9_62_characteristic_two_field) 360 is_char_two = 1; 361 362 if ((tx = BN_CTX_get(ctx)) == NULL) 363 goto err; 364 if ((ty = BN_CTX_get(ctx)) == NULL) 365 goto err; 366 367 #ifndef OPENSSL_NO_EC2M 368 if (is_char_two) { 369 if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point, 370 x, y, ctx)) 371 goto err; 372 if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point, 373 tx, ty, ctx)) 374 goto err; 375 } else 376 #endif 377 { 378 if (!EC_POINT_set_affine_coordinates_GFp(key->group, point, 379 x, y, ctx)) 380 goto err; 381 if (!EC_POINT_get_affine_coordinates_GFp(key->group, point, 382 tx, ty, ctx)) 383 goto err; 384 } 385 /* 386 * Check if retrieved coordinates match originals: if not values are 387 * out of range. 388 */ 389 if (BN_cmp(x, tx) || BN_cmp(y, ty)) { 390 ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES, 391 EC_R_COORDINATES_OUT_OF_RANGE); 392 goto err; 393 } 394 if (!EC_KEY_set_public_key(key, point)) 395 goto err; 396 397 if (EC_KEY_check_key(key) == 0) 398 goto err; 399 400 ok = 1; 401 402 err: 403 BN_CTX_free(ctx); 404 EC_POINT_free(point); 405 return ok; 406 407 } 408 409 const EC_GROUP * 410 EC_KEY_get0_group(const EC_KEY * key) 411 { 412 return key->group; 413 } 414 415 int 416 EC_KEY_set_group(EC_KEY * key, const EC_GROUP * group) 417 { 418 EC_GROUP_free(key->group); 419 key->group = EC_GROUP_dup(group); 420 return (key->group == NULL) ? 0 : 1; 421 } 422 423 const BIGNUM * 424 EC_KEY_get0_private_key(const EC_KEY * key) 425 { 426 return key->priv_key; 427 } 428 429 int 430 EC_KEY_set_private_key(EC_KEY * key, const BIGNUM * priv_key) 431 { 432 BN_clear_free(key->priv_key); 433 key->priv_key = BN_dup(priv_key); 434 return (key->priv_key == NULL) ? 0 : 1; 435 } 436 437 const EC_POINT * 438 EC_KEY_get0_public_key(const EC_KEY * key) 439 { 440 return key->pub_key; 441 } 442 443 int 444 EC_KEY_set_public_key(EC_KEY * key, const EC_POINT * pub_key) 445 { 446 EC_POINT_free(key->pub_key); 447 key->pub_key = EC_POINT_dup(pub_key, key->group); 448 return (key->pub_key == NULL) ? 0 : 1; 449 } 450 451 unsigned int 452 EC_KEY_get_enc_flags(const EC_KEY * key) 453 { 454 return key->enc_flag; 455 } 456 457 void 458 EC_KEY_set_enc_flags(EC_KEY * key, unsigned int flags) 459 { 460 key->enc_flag = flags; 461 } 462 463 point_conversion_form_t 464 EC_KEY_get_conv_form(const EC_KEY * key) 465 { 466 return key->conv_form; 467 } 468 469 void 470 EC_KEY_set_conv_form(EC_KEY * key, point_conversion_form_t cform) 471 { 472 key->conv_form = cform; 473 if (key->group != NULL) 474 EC_GROUP_set_point_conversion_form(key->group, cform); 475 } 476 477 void * 478 EC_KEY_get_key_method_data(EC_KEY *key, 479 void *(*dup_func) (void *), 480 void (*free_func) (void *), 481 void (*clear_free_func) (void *)) 482 { 483 void *ret; 484 485 CRYPTO_r_lock(CRYPTO_LOCK_EC); 486 ret = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func); 487 CRYPTO_r_unlock(CRYPTO_LOCK_EC); 488 489 return ret; 490 } 491 492 void * 493 EC_KEY_insert_key_method_data(EC_KEY * key, void *data, 494 void *(*dup_func) (void *), 495 void (*free_func) (void *), 496 void (*clear_free_func) (void *)) 497 { 498 EC_EXTRA_DATA *ex_data; 499 500 CRYPTO_w_lock(CRYPTO_LOCK_EC); 501 ex_data = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func); 502 if (ex_data == NULL) 503 EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func, clear_free_func); 504 CRYPTO_w_unlock(CRYPTO_LOCK_EC); 505 506 return ex_data; 507 } 508 509 void 510 EC_KEY_set_asn1_flag(EC_KEY * key, int flag) 511 { 512 if (key->group != NULL) 513 EC_GROUP_set_asn1_flag(key->group, flag); 514 } 515 516 int 517 EC_KEY_precompute_mult(EC_KEY * key, BN_CTX * ctx) 518 { 519 if (key->group == NULL) 520 return 0; 521 return EC_GROUP_precompute_mult(key->group, ctx); 522 } 523 524 int 525 EC_KEY_get_flags(const EC_KEY * key) 526 { 527 return key->flags; 528 } 529 530 void 531 EC_KEY_set_flags(EC_KEY * key, int flags) 532 { 533 key->flags |= flags; 534 } 535 536 void 537 EC_KEY_clear_flags(EC_KEY * key, int flags) 538 { 539 key->flags &= ~flags; 540 } 541