1 /* $OpenBSD: ec_key.c,v 1.13 2017/01/29 17:49:23 beck 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 explicit_bzero((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 ECerror(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 ECerror(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 ECerror(ERR_R_PASSED_NULL_PARAMETER); 278 return 0; 279 } 280 if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key) > 0) { 281 ECerror(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 ECerror(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 ECerror(EC_R_INVALID_GROUP_ORDER); 298 goto err; 299 } 300 if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) { 301 ECerror(ERR_R_EC_LIB); 302 goto err; 303 } 304 if (EC_POINT_is_at_infinity(eckey->group, point) <= 0) { 305 ECerror(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 ECerror(EC_R_WRONG_ORDER); 315 goto err; 316 } 317 if (!EC_POINT_mul(eckey->group, point, eckey->priv_key, 318 NULL, NULL, ctx)) { 319 ECerror(ERR_R_EC_LIB); 320 goto err; 321 } 322 if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, 323 ctx) != 0) { 324 ECerror(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 ECerror(ERR_R_PASSED_NULL_PARAMETER); 345 return 0; 346 } 347 ctx = BN_CTX_new(); 348 if (!ctx) 349 goto err; 350 351 point = EC_POINT_new(key->group); 352 353 if (!point) 354 goto err; 355 356 tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group)); 357 358 if (tmp_nid == NID_X9_62_characteristic_two_field) 359 is_char_two = 1; 360 361 if ((tx = BN_CTX_get(ctx)) == NULL) 362 goto err; 363 if ((ty = BN_CTX_get(ctx)) == NULL) 364 goto err; 365 366 #ifndef OPENSSL_NO_EC2M 367 if (is_char_two) { 368 if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point, 369 x, y, ctx)) 370 goto err; 371 if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point, 372 tx, ty, ctx)) 373 goto err; 374 } else 375 #endif 376 { 377 if (!EC_POINT_set_affine_coordinates_GFp(key->group, point, 378 x, y, ctx)) 379 goto err; 380 if (!EC_POINT_get_affine_coordinates_GFp(key->group, point, 381 tx, ty, ctx)) 382 goto err; 383 } 384 /* 385 * Check if retrieved coordinates match originals: if not values are 386 * out of range. 387 */ 388 if (BN_cmp(x, tx) || BN_cmp(y, ty)) { 389 ECerror(EC_R_COORDINATES_OUT_OF_RANGE); 390 goto err; 391 } 392 if (!EC_KEY_set_public_key(key, point)) 393 goto err; 394 395 if (EC_KEY_check_key(key) == 0) 396 goto err; 397 398 ok = 1; 399 400 err: 401 BN_CTX_free(ctx); 402 EC_POINT_free(point); 403 return ok; 404 405 } 406 407 const EC_GROUP * 408 EC_KEY_get0_group(const EC_KEY * key) 409 { 410 return key->group; 411 } 412 413 int 414 EC_KEY_set_group(EC_KEY * key, const EC_GROUP * group) 415 { 416 EC_GROUP_free(key->group); 417 key->group = EC_GROUP_dup(group); 418 return (key->group == NULL) ? 0 : 1; 419 } 420 421 const BIGNUM * 422 EC_KEY_get0_private_key(const EC_KEY * key) 423 { 424 return key->priv_key; 425 } 426 427 int 428 EC_KEY_set_private_key(EC_KEY * key, const BIGNUM * priv_key) 429 { 430 BN_clear_free(key->priv_key); 431 key->priv_key = BN_dup(priv_key); 432 return (key->priv_key == NULL) ? 0 : 1; 433 } 434 435 const EC_POINT * 436 EC_KEY_get0_public_key(const EC_KEY * key) 437 { 438 return key->pub_key; 439 } 440 441 int 442 EC_KEY_set_public_key(EC_KEY * key, const EC_POINT * pub_key) 443 { 444 EC_POINT_free(key->pub_key); 445 key->pub_key = EC_POINT_dup(pub_key, key->group); 446 return (key->pub_key == NULL) ? 0 : 1; 447 } 448 449 unsigned int 450 EC_KEY_get_enc_flags(const EC_KEY * key) 451 { 452 return key->enc_flag; 453 } 454 455 void 456 EC_KEY_set_enc_flags(EC_KEY * key, unsigned int flags) 457 { 458 key->enc_flag = flags; 459 } 460 461 point_conversion_form_t 462 EC_KEY_get_conv_form(const EC_KEY * key) 463 { 464 return key->conv_form; 465 } 466 467 void 468 EC_KEY_set_conv_form(EC_KEY * key, point_conversion_form_t cform) 469 { 470 key->conv_form = cform; 471 if (key->group != NULL) 472 EC_GROUP_set_point_conversion_form(key->group, cform); 473 } 474 475 void * 476 EC_KEY_get_key_method_data(EC_KEY *key, 477 void *(*dup_func) (void *), 478 void (*free_func) (void *), 479 void (*clear_free_func) (void *)) 480 { 481 void *ret; 482 483 CRYPTO_r_lock(CRYPTO_LOCK_EC); 484 ret = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func); 485 CRYPTO_r_unlock(CRYPTO_LOCK_EC); 486 487 return ret; 488 } 489 490 void * 491 EC_KEY_insert_key_method_data(EC_KEY * key, void *data, 492 void *(*dup_func) (void *), 493 void (*free_func) (void *), 494 void (*clear_free_func) (void *)) 495 { 496 EC_EXTRA_DATA *ex_data; 497 498 CRYPTO_w_lock(CRYPTO_LOCK_EC); 499 ex_data = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func); 500 if (ex_data == NULL) 501 EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func, clear_free_func); 502 CRYPTO_w_unlock(CRYPTO_LOCK_EC); 503 504 return ex_data; 505 } 506 507 void 508 EC_KEY_set_asn1_flag(EC_KEY * key, int flag) 509 { 510 if (key->group != NULL) 511 EC_GROUP_set_asn1_flag(key->group, flag); 512 } 513 514 int 515 EC_KEY_precompute_mult(EC_KEY * key, BN_CTX * ctx) 516 { 517 if (key->group == NULL) 518 return 0; 519 return EC_GROUP_precompute_mult(key->group, ctx); 520 } 521 522 int 523 EC_KEY_get_flags(const EC_KEY * key) 524 { 525 return key->flags; 526 } 527 528 void 529 EC_KEY_set_flags(EC_KEY * key, int flags) 530 { 531 key->flags |= flags; 532 } 533 534 void 535 EC_KEY_clear_flags(EC_KEY * key, int flags) 536 { 537 key->flags &= ~flags; 538 } 539