1 /* $OpenBSD: ec_ameth.c,v 1.31 2022/01/10 12:10:26 tb Exp $ */ 2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL 3 * project 2006. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 2006 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 * licensing@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 #include <stdio.h> 60 61 #include <openssl/opensslconf.h> 62 63 #include <openssl/bn.h> 64 #include <openssl/cms.h> 65 #include <openssl/ec.h> 66 #include <openssl/err.h> 67 #include <openssl/x509.h> 68 69 #include "asn1_locl.h" 70 #include "ec_lcl.h" 71 #include "evp_locl.h" 72 73 #ifndef OPENSSL_NO_CMS 74 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri); 75 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri); 76 #endif 77 78 static int 79 eckey_param2type(int *pptype, void **ppval, EC_KEY * ec_key) 80 { 81 const EC_GROUP *group; 82 int nid; 83 if (ec_key == NULL || (group = EC_KEY_get0_group(ec_key)) == NULL) { 84 ECerror(EC_R_MISSING_PARAMETERS); 85 return 0; 86 } 87 if (EC_GROUP_get_asn1_flag(group) && 88 (nid = EC_GROUP_get_curve_name(group))) { 89 /* we have a 'named curve' => just set the OID */ 90 *ppval = OBJ_nid2obj(nid); 91 *pptype = V_ASN1_OBJECT; 92 } else { 93 /* explicit parameters */ 94 ASN1_STRING *pstr = NULL; 95 pstr = ASN1_STRING_new(); 96 if (!pstr) 97 return 0; 98 pstr->length = i2d_ECParameters(ec_key, &pstr->data); 99 if (pstr->length <= 0) { 100 ASN1_STRING_free(pstr); 101 ECerror(ERR_R_EC_LIB); 102 return 0; 103 } 104 *ppval = pstr; 105 *pptype = V_ASN1_SEQUENCE; 106 } 107 return 1; 108 } 109 110 static int 111 eckey_pub_encode(X509_PUBKEY * pk, const EVP_PKEY * pkey) 112 { 113 EC_KEY *ec_key = pkey->pkey.ec; 114 void *pval = NULL; 115 int ptype; 116 unsigned char *penc = NULL, *p; 117 int penclen; 118 119 if (!eckey_param2type(&ptype, &pval, ec_key)) { 120 ECerror(ERR_R_EC_LIB); 121 return 0; 122 } 123 penclen = i2o_ECPublicKey(ec_key, NULL); 124 if (penclen <= 0) 125 goto err; 126 penc = malloc(penclen); 127 if (!penc) 128 goto err; 129 p = penc; 130 penclen = i2o_ECPublicKey(ec_key, &p); 131 if (penclen <= 0) 132 goto err; 133 if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(EVP_PKEY_EC), 134 ptype, pval, penc, penclen)) 135 return 1; 136 err: 137 if (ptype == V_ASN1_OBJECT) 138 ASN1_OBJECT_free(pval); 139 else 140 ASN1_STRING_free(pval); 141 free(penc); 142 return 0; 143 } 144 145 static EC_KEY * 146 eckey_type2param(int ptype, const void *pval) 147 { 148 EC_GROUP *group = NULL; 149 EC_KEY *eckey = NULL; 150 151 if (ptype == V_ASN1_SEQUENCE) { 152 const ASN1_STRING *pstr = pval; 153 const unsigned char *pm = NULL; 154 int pmlen; 155 156 pm = pstr->data; 157 pmlen = pstr->length; 158 if (!(eckey = d2i_ECParameters(NULL, &pm, pmlen))) { 159 ECerror(EC_R_DECODE_ERROR); 160 goto ecerr; 161 } 162 } else if (ptype == V_ASN1_OBJECT) { 163 const ASN1_OBJECT *poid = pval; 164 165 /* 166 * type == V_ASN1_OBJECT => the parameters are given by an 167 * asn1 OID 168 */ 169 if ((eckey = EC_KEY_new()) == NULL) { 170 ECerror(ERR_R_MALLOC_FAILURE); 171 goto ecerr; 172 } 173 group = EC_GROUP_new_by_curve_name(OBJ_obj2nid(poid)); 174 if (group == NULL) 175 goto ecerr; 176 EC_GROUP_set_asn1_flag(group, OPENSSL_EC_NAMED_CURVE); 177 if (EC_KEY_set_group(eckey, group) == 0) 178 goto ecerr; 179 } else { 180 ECerror(EC_R_DECODE_ERROR); 181 goto ecerr; 182 } 183 184 EC_GROUP_free(group); 185 return eckey; 186 187 ecerr: 188 EC_KEY_free(eckey); 189 EC_GROUP_free(group); 190 return NULL; 191 } 192 193 static int 194 eckey_pub_decode(EVP_PKEY * pkey, X509_PUBKEY * pubkey) 195 { 196 const unsigned char *p = NULL; 197 const void *pval; 198 int ptype, pklen; 199 EC_KEY *eckey = NULL; 200 X509_ALGOR *palg; 201 202 if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey)) 203 return 0; 204 X509_ALGOR_get0(NULL, &ptype, &pval, palg); 205 206 eckey = eckey_type2param(ptype, pval); 207 208 if (!eckey) { 209 ECerror(ERR_R_EC_LIB); 210 return 0; 211 } 212 /* We have parameters now set public key */ 213 if (!o2i_ECPublicKey(&eckey, &p, pklen)) { 214 ECerror(EC_R_DECODE_ERROR); 215 goto ecerr; 216 } 217 EVP_PKEY_assign_EC_KEY(pkey, eckey); 218 return 1; 219 220 ecerr: 221 if (eckey) 222 EC_KEY_free(eckey); 223 return 0; 224 } 225 226 static int 227 eckey_pub_cmp(const EVP_PKEY * a, const EVP_PKEY * b) 228 { 229 int r; 230 const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec); 231 const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec), *pb = EC_KEY_get0_public_key(b->pkey.ec); 232 233 r = EC_POINT_cmp(group, pa, pb, NULL); 234 if (r == 0) 235 return 1; 236 if (r == 1) 237 return 0; 238 return -2; 239 } 240 241 static int 242 eckey_priv_decode(EVP_PKEY * pkey, const PKCS8_PRIV_KEY_INFO * p8) 243 { 244 const unsigned char *p = NULL; 245 const void *pval; 246 int ptype, pklen; 247 EC_KEY *eckey = NULL; 248 const X509_ALGOR *palg; 249 250 if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8)) 251 return 0; 252 X509_ALGOR_get0(NULL, &ptype, &pval, palg); 253 254 eckey = eckey_type2param(ptype, pval); 255 256 if (!eckey) 257 goto ecliberr; 258 259 /* We have parameters now set private key */ 260 if (!d2i_ECPrivateKey(&eckey, &p, pklen)) { 261 ECerror(EC_R_DECODE_ERROR); 262 goto ecerr; 263 } 264 /* calculate public key (if necessary) */ 265 if (EC_KEY_get0_public_key(eckey) == NULL) { 266 const BIGNUM *priv_key; 267 const EC_GROUP *group; 268 EC_POINT *pub_key; 269 /* 270 * the public key was not included in the SEC1 private key => 271 * calculate the public key 272 */ 273 group = EC_KEY_get0_group(eckey); 274 pub_key = EC_POINT_new(group); 275 if (pub_key == NULL) { 276 ECerror(ERR_R_EC_LIB); 277 goto ecliberr; 278 } 279 if (!EC_POINT_copy(pub_key, EC_GROUP_get0_generator(group))) { 280 EC_POINT_free(pub_key); 281 ECerror(ERR_R_EC_LIB); 282 goto ecliberr; 283 } 284 priv_key = EC_KEY_get0_private_key(eckey); 285 if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, NULL)) { 286 EC_POINT_free(pub_key); 287 ECerror(ERR_R_EC_LIB); 288 goto ecliberr; 289 } 290 if (EC_KEY_set_public_key(eckey, pub_key) == 0) { 291 EC_POINT_free(pub_key); 292 ECerror(ERR_R_EC_LIB); 293 goto ecliberr; 294 } 295 EC_POINT_free(pub_key); 296 } 297 EVP_PKEY_assign_EC_KEY(pkey, eckey); 298 return 1; 299 300 ecliberr: 301 ECerror(ERR_R_EC_LIB); 302 ecerr: 303 if (eckey) 304 EC_KEY_free(eckey); 305 return 0; 306 } 307 308 static int 309 eckey_priv_encode(PKCS8_PRIV_KEY_INFO * p8, const EVP_PKEY * pkey) 310 { 311 EC_KEY *ec_key; 312 unsigned char *ep, *p; 313 int eplen, ptype; 314 void *pval; 315 unsigned int tmp_flags, old_flags; 316 317 ec_key = pkey->pkey.ec; 318 319 if (!eckey_param2type(&ptype, &pval, ec_key)) { 320 ECerror(EC_R_DECODE_ERROR); 321 return 0; 322 } 323 /* set the private key */ 324 325 /* 326 * do not include the parameters in the SEC1 private key see PKCS#11 327 * 12.11 328 */ 329 old_flags = EC_KEY_get_enc_flags(ec_key); 330 tmp_flags = old_flags | EC_PKEY_NO_PARAMETERS; 331 EC_KEY_set_enc_flags(ec_key, tmp_flags); 332 eplen = i2d_ECPrivateKey(ec_key, NULL); 333 if (!eplen) { 334 EC_KEY_set_enc_flags(ec_key, old_flags); 335 ECerror(ERR_R_EC_LIB); 336 return 0; 337 } 338 ep = malloc(eplen); 339 if (!ep) { 340 EC_KEY_set_enc_flags(ec_key, old_flags); 341 ECerror(ERR_R_MALLOC_FAILURE); 342 return 0; 343 } 344 p = ep; 345 if (!i2d_ECPrivateKey(ec_key, &p)) { 346 EC_KEY_set_enc_flags(ec_key, old_flags); 347 free(ep); 348 ECerror(ERR_R_EC_LIB); 349 return 0; 350 } 351 /* restore old encoding flags */ 352 EC_KEY_set_enc_flags(ec_key, old_flags); 353 354 if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0, 355 ptype, pval, ep, eplen)) 356 return 0; 357 358 return 1; 359 } 360 361 static int 362 int_ec_size(const EVP_PKEY * pkey) 363 { 364 return ECDSA_size(pkey->pkey.ec); 365 } 366 367 static int 368 ec_bits(const EVP_PKEY * pkey) 369 { 370 BIGNUM *order = BN_new(); 371 const EC_GROUP *group; 372 int ret; 373 374 if (!order) { 375 ERR_clear_error(); 376 return 0; 377 } 378 group = EC_KEY_get0_group(pkey->pkey.ec); 379 if (!EC_GROUP_get_order(group, order, NULL)) { 380 BN_free(order); 381 ERR_clear_error(); 382 return 0; 383 } 384 ret = BN_num_bits(order); 385 BN_free(order); 386 return ret; 387 } 388 389 static int 390 ec_missing_parameters(const EVP_PKEY * pkey) 391 { 392 if (EC_KEY_get0_group(pkey->pkey.ec) == NULL) 393 return 1; 394 return 0; 395 } 396 397 static int 398 ec_copy_parameters(EVP_PKEY * to, const EVP_PKEY * from) 399 { 400 return EC_KEY_set_group(to->pkey.ec, EC_KEY_get0_group(from->pkey.ec)); 401 } 402 403 static int 404 ec_cmp_parameters(const EVP_PKEY * a, const EVP_PKEY * b) 405 { 406 const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec), *group_b = EC_KEY_get0_group(b->pkey.ec); 407 if (EC_GROUP_cmp(group_a, group_b, NULL)) 408 return 0; 409 else 410 return 1; 411 } 412 413 static void 414 int_ec_free(EVP_PKEY * pkey) 415 { 416 EC_KEY_free(pkey->pkey.ec); 417 } 418 419 static int 420 do_EC_KEY_print(BIO * bp, const EC_KEY * x, int off, int ktype) 421 { 422 unsigned char *buffer = NULL; 423 const char *ecstr; 424 size_t buf_len = 0, i; 425 int ret = 0, reason = ERR_R_BIO_LIB; 426 BIGNUM *pub_key = NULL, *order = NULL; 427 BN_CTX *ctx = NULL; 428 const EC_GROUP *group; 429 const EC_POINT *public_key; 430 const BIGNUM *priv_key; 431 432 if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL) { 433 reason = ERR_R_PASSED_NULL_PARAMETER; 434 goto err; 435 } 436 ctx = BN_CTX_new(); 437 if (ctx == NULL) { 438 reason = ERR_R_MALLOC_FAILURE; 439 goto err; 440 } 441 if (ktype > 0) { 442 public_key = EC_KEY_get0_public_key(x); 443 if (public_key != NULL) { 444 if ((pub_key = EC_POINT_point2bn(group, public_key, 445 EC_KEY_get_conv_form(x), NULL, ctx)) == NULL) { 446 reason = ERR_R_EC_LIB; 447 goto err; 448 } 449 if (pub_key) 450 buf_len = (size_t) BN_num_bytes(pub_key); 451 } 452 } 453 if (ktype == 2) { 454 priv_key = EC_KEY_get0_private_key(x); 455 if (priv_key && (i = (size_t) BN_num_bytes(priv_key)) > buf_len) 456 buf_len = i; 457 } else 458 priv_key = NULL; 459 460 if (ktype > 0) { 461 buf_len += 10; 462 if ((buffer = malloc(buf_len)) == NULL) { 463 reason = ERR_R_MALLOC_FAILURE; 464 goto err; 465 } 466 } 467 if (ktype == 2) 468 ecstr = "Private-Key"; 469 else if (ktype == 1) 470 ecstr = "Public-Key"; 471 else 472 ecstr = "ECDSA-Parameters"; 473 474 if (!BIO_indent(bp, off, 128)) 475 goto err; 476 if ((order = BN_new()) == NULL) 477 goto err; 478 if (!EC_GROUP_get_order(group, order, NULL)) 479 goto err; 480 if (BIO_printf(bp, "%s: (%d bit)\n", ecstr, 481 BN_num_bits(order)) <= 0) 482 goto err; 483 484 if ((priv_key != NULL) && !ASN1_bn_print(bp, "priv:", priv_key, 485 buffer, off)) 486 goto err; 487 if ((pub_key != NULL) && !ASN1_bn_print(bp, "pub: ", pub_key, 488 buffer, off)) 489 goto err; 490 if (!ECPKParameters_print(bp, group, off)) 491 goto err; 492 ret = 1; 493 err: 494 if (!ret) 495 ECerror(reason); 496 BN_free(pub_key); 497 BN_free(order); 498 BN_CTX_free(ctx); 499 free(buffer); 500 return (ret); 501 } 502 503 static int 504 eckey_param_decode(EVP_PKEY * pkey, 505 const unsigned char **pder, int derlen) 506 { 507 EC_KEY *eckey; 508 if (!(eckey = d2i_ECParameters(NULL, pder, derlen))) { 509 ECerror(ERR_R_EC_LIB); 510 return 0; 511 } 512 EVP_PKEY_assign_EC_KEY(pkey, eckey); 513 return 1; 514 } 515 516 static int 517 eckey_param_encode(const EVP_PKEY * pkey, unsigned char **pder) 518 { 519 return i2d_ECParameters(pkey->pkey.ec, pder); 520 } 521 522 static int 523 eckey_param_print(BIO * bp, const EVP_PKEY * pkey, int indent, 524 ASN1_PCTX * ctx) 525 { 526 return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 0); 527 } 528 529 static int 530 eckey_pub_print(BIO * bp, const EVP_PKEY * pkey, int indent, 531 ASN1_PCTX * ctx) 532 { 533 return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 1); 534 } 535 536 537 static int 538 eckey_priv_print(BIO * bp, const EVP_PKEY * pkey, int indent, 539 ASN1_PCTX * ctx) 540 { 541 return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 2); 542 } 543 544 static int 545 old_ec_priv_decode(EVP_PKEY * pkey, 546 const unsigned char **pder, int derlen) 547 { 548 EC_KEY *ec; 549 if (!(ec = d2i_ECPrivateKey(NULL, pder, derlen))) { 550 ECerror(EC_R_DECODE_ERROR); 551 return 0; 552 } 553 EVP_PKEY_assign_EC_KEY(pkey, ec); 554 return 1; 555 } 556 557 static int 558 old_ec_priv_encode(const EVP_PKEY * pkey, unsigned char **pder) 559 { 560 return i2d_ECPrivateKey(pkey->pkey.ec, pder); 561 } 562 563 static int 564 ec_pkey_ctrl(EVP_PKEY * pkey, int op, long arg1, void *arg2) 565 { 566 switch (op) { 567 case ASN1_PKEY_CTRL_PKCS7_SIGN: 568 if (arg1 == 0) { 569 int snid, hnid; 570 X509_ALGOR *alg1, *alg2; 571 PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2); 572 if (alg1 == NULL || alg1->algorithm == NULL) 573 return -1; 574 hnid = OBJ_obj2nid(alg1->algorithm); 575 if (hnid == NID_undef) 576 return -1; 577 if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey))) 578 return -1; 579 X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0); 580 } 581 return 1; 582 583 #ifndef OPENSSL_NO_CMS 584 case ASN1_PKEY_CTRL_CMS_SIGN: 585 if (arg1 == 0) { 586 X509_ALGOR *alg1, *alg2; 587 int snid, hnid; 588 589 CMS_SignerInfo_get0_algs(arg2, NULL, NULL, &alg1, &alg2); 590 if (alg1 == NULL || alg1->algorithm == NULL) 591 return -1; 592 hnid = OBJ_obj2nid(alg1->algorithm); 593 if (hnid == NID_undef) 594 return -1; 595 if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey))) 596 return -1; 597 X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0); 598 } 599 return 1; 600 601 case ASN1_PKEY_CTRL_CMS_ENVELOPE: 602 if (arg1 == 0) 603 return ecdh_cms_encrypt(arg2); 604 else if (arg1 == 1) 605 return ecdh_cms_decrypt(arg2); 606 return -2; 607 608 case ASN1_PKEY_CTRL_CMS_RI_TYPE: 609 *(int *)arg2 = CMS_RECIPINFO_AGREE; 610 return 1; 611 #endif 612 613 case ASN1_PKEY_CTRL_DEFAULT_MD_NID: 614 *(int *) arg2 = NID_sha1; 615 return 2; 616 617 default: 618 return -2; 619 620 } 621 622 } 623 624 static int 625 ec_pkey_check(const EVP_PKEY *pkey) 626 { 627 EC_KEY *eckey = pkey->pkey.ec; 628 629 if (eckey->priv_key == NULL) { 630 ECerror(EC_R_MISSING_PRIVATE_KEY); 631 return 0; 632 } 633 634 return EC_KEY_check_key(eckey); 635 } 636 637 static int 638 ec_pkey_public_check(const EVP_PKEY *pkey) 639 { 640 EC_KEY *eckey = pkey->pkey.ec; 641 642 /* This also checks the private key, but oh, well... */ 643 return EC_KEY_check_key(eckey); 644 } 645 646 static int 647 ec_pkey_param_check(const EVP_PKEY *pkey) 648 { 649 EC_KEY *eckey = pkey->pkey.ec; 650 651 if (eckey->group == NULL) { 652 ECerror(EC_R_MISSING_PARAMETERS); 653 return 0; 654 } 655 656 return EC_GROUP_check(eckey->group, NULL); 657 } 658 659 #ifndef OPENSSL_NO_CMS 660 661 static int 662 ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx, X509_ALGOR *alg, 663 ASN1_BIT_STRING *pubkey) 664 { 665 const ASN1_OBJECT *aoid; 666 int atype; 667 const void *aval; 668 int rv = 0; 669 EVP_PKEY *pkpeer = NULL; 670 EC_KEY *ecpeer = NULL; 671 const unsigned char *p; 672 int plen; 673 674 X509_ALGOR_get0(&aoid, &atype, &aval, alg); 675 if (OBJ_obj2nid(aoid) != NID_X9_62_id_ecPublicKey) 676 goto err; 677 678 /* If absent parameters get group from main key */ 679 if (atype == V_ASN1_UNDEF || atype == V_ASN1_NULL) { 680 const EC_GROUP *grp; 681 EVP_PKEY *pk; 682 683 pk = EVP_PKEY_CTX_get0_pkey(pctx); 684 if (!pk) 685 goto err; 686 grp = EC_KEY_get0_group(pk->pkey.ec); 687 ecpeer = EC_KEY_new(); 688 if (ecpeer == NULL) 689 goto err; 690 if (!EC_KEY_set_group(ecpeer, grp)) 691 goto err; 692 } else { 693 ecpeer = eckey_type2param(atype, aval); 694 if (!ecpeer) 695 goto err; 696 } 697 698 /* We have parameters now set public key */ 699 plen = ASN1_STRING_length(pubkey); 700 p = ASN1_STRING_get0_data(pubkey); 701 if (!p || !plen) 702 goto err; 703 if (!o2i_ECPublicKey(&ecpeer, &p, plen)) 704 goto err; 705 pkpeer = EVP_PKEY_new(); 706 if (pkpeer == NULL) 707 goto err; 708 EVP_PKEY_set1_EC_KEY(pkpeer, ecpeer); 709 if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0) 710 rv = 1; 711 err: 712 EC_KEY_free(ecpeer); 713 EVP_PKEY_free(pkpeer); 714 return rv; 715 } 716 717 /* Set KDF parameters based on KDF NID */ 718 static int 719 ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid) 720 { 721 int kdf_nid, kdfmd_nid, cofactor; 722 const EVP_MD *kdf_md; 723 724 if (eckdf_nid == NID_undef) 725 return 0; 726 727 /* Lookup KDF type, cofactor mode and digest */ 728 if (!OBJ_find_sigid_algs(eckdf_nid, &kdfmd_nid, &kdf_nid)) 729 return 0; 730 731 if (kdf_nid == NID_dh_std_kdf) 732 cofactor = 0; 733 else if (kdf_nid == NID_dh_cofactor_kdf) 734 cofactor = 1; 735 else 736 return 0; 737 738 if (EVP_PKEY_CTX_set_ecdh_cofactor_mode(pctx, cofactor) <= 0) 739 return 0; 740 741 if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, EVP_PKEY_ECDH_KDF_X9_63) <= 0) 742 return 0; 743 744 kdf_md = EVP_get_digestbynid(kdfmd_nid); 745 if (!kdf_md) 746 return 0; 747 748 if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0) 749 return 0; 750 751 return 1; 752 } 753 754 static int 755 ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri) 756 { 757 X509_ALGOR *alg, *kekalg = NULL; 758 ASN1_OCTET_STRING *ukm; 759 const unsigned char *p; 760 unsigned char *der = NULL; 761 int plen, keylen; 762 const EVP_CIPHER *kekcipher; 763 EVP_CIPHER_CTX *kekctx; 764 int rv = 0; 765 766 if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm)) 767 return 0; 768 769 if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) { 770 ECerror(EC_R_KDF_PARAMETER_ERROR); 771 return 0; 772 } 773 774 if (alg->parameter->type != V_ASN1_SEQUENCE) 775 return 0; 776 777 p = alg->parameter->value.sequence->data; 778 plen = alg->parameter->value.sequence->length; 779 kekalg = d2i_X509_ALGOR(NULL, &p, plen); 780 if (!kekalg) 781 goto err; 782 kekctx = CMS_RecipientInfo_kari_get0_ctx(ri); 783 if (!kekctx) 784 goto err; 785 kekcipher = EVP_get_cipherbyobj(kekalg->algorithm); 786 if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE) 787 goto err; 788 if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL)) 789 goto err; 790 if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0) 791 goto err; 792 793 keylen = EVP_CIPHER_CTX_key_length(kekctx); 794 if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0) 795 goto err; 796 797 plen = CMS_SharedInfo_encode(&der, kekalg, ukm, keylen); 798 if (!plen) 799 goto err; 800 801 if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0) 802 goto err; 803 der = NULL; 804 805 rv = 1; 806 err: 807 X509_ALGOR_free(kekalg); 808 free(der); 809 return rv; 810 } 811 812 static int 813 ecdh_cms_decrypt(CMS_RecipientInfo *ri) 814 { 815 EVP_PKEY_CTX *pctx; 816 817 pctx = CMS_RecipientInfo_get0_pkey_ctx(ri); 818 if (!pctx) 819 return 0; 820 821 /* See if we need to set peer key */ 822 if (!EVP_PKEY_CTX_get0_peerkey(pctx)) { 823 X509_ALGOR *alg; 824 ASN1_BIT_STRING *pubkey; 825 826 if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey, 827 NULL, NULL, NULL)) 828 return 0; 829 if (!alg || !pubkey) 830 return 0; 831 if (!ecdh_cms_set_peerkey(pctx, alg, pubkey)) { 832 ECerror(EC_R_PEER_KEY_ERROR); 833 return 0; 834 } 835 } 836 837 /* Set ECDH derivation parameters and initialise unwrap context */ 838 if (!ecdh_cms_set_shared_info(pctx, ri)) { 839 ECerror(EC_R_SHARED_INFO_ERROR); 840 return 0; 841 } 842 843 return 1; 844 } 845 846 static int 847 ecdh_cms_encrypt(CMS_RecipientInfo *ri) 848 { 849 EVP_PKEY_CTX *pctx; 850 EVP_PKEY *pkey; 851 EVP_CIPHER_CTX *ctx; 852 int keylen; 853 X509_ALGOR *talg, *wrap_alg = NULL; 854 const ASN1_OBJECT *aoid; 855 ASN1_BIT_STRING *pubkey; 856 ASN1_STRING *wrap_str; 857 ASN1_OCTET_STRING *ukm; 858 unsigned char *penc = NULL; 859 int penclen; 860 int ecdh_nid, kdf_type, kdf_nid, wrap_nid; 861 const EVP_MD *kdf_md; 862 int rv = 0; 863 864 pctx = CMS_RecipientInfo_get0_pkey_ctx(ri); 865 if (!pctx) 866 return 0; 867 /* Get ephemeral key */ 868 pkey = EVP_PKEY_CTX_get0_pkey(pctx); 869 if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey, 870 NULL, NULL, NULL)) 871 goto err; 872 X509_ALGOR_get0(&aoid, NULL, NULL, talg); 873 874 /* Is everything uninitialised? */ 875 if (aoid == OBJ_nid2obj(NID_undef)) { 876 EC_KEY *eckey = pkey->pkey.ec; 877 unsigned char *p; 878 879 /* Set the key */ 880 penclen = i2o_ECPublicKey(eckey, NULL); 881 if (penclen <= 0) 882 goto err; 883 penc = malloc(penclen); 884 if (penc == NULL) 885 goto err; 886 p = penc; 887 penclen = i2o_ECPublicKey(eckey, &p); 888 if (penclen <= 0) 889 goto err; 890 ASN1_STRING_set0(pubkey, penc, penclen); 891 pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); 892 pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT; 893 penc = NULL; 894 895 X509_ALGOR_set0(talg, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 896 V_ASN1_UNDEF, NULL); 897 } 898 899 /* See if custom parameters set */ 900 kdf_type = EVP_PKEY_CTX_get_ecdh_kdf_type(pctx); 901 if (kdf_type <= 0) 902 goto err; 903 if (!EVP_PKEY_CTX_get_ecdh_kdf_md(pctx, &kdf_md)) 904 goto err; 905 ecdh_nid = EVP_PKEY_CTX_get_ecdh_cofactor_mode(pctx); 906 if (ecdh_nid < 0) 907 goto err; 908 else if (ecdh_nid == 0) 909 ecdh_nid = NID_dh_std_kdf; 910 else if (ecdh_nid == 1) 911 ecdh_nid = NID_dh_cofactor_kdf; 912 913 if (kdf_type == EVP_PKEY_ECDH_KDF_NONE) { 914 kdf_type = EVP_PKEY_ECDH_KDF_X9_63; 915 if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0) 916 goto err; 917 } else { 918 /* Unknown KDF */ 919 goto err; 920 } 921 if (kdf_md == NULL) { 922 /* Fixme later for better MD */ 923 kdf_md = EVP_sha1(); 924 if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0) 925 goto err; 926 } 927 928 if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm)) 929 goto err; 930 931 /* Lookup NID for KDF+cofactor+digest */ 932 if (!OBJ_find_sigid_by_algs(&kdf_nid, EVP_MD_type(kdf_md), ecdh_nid)) 933 goto err; 934 935 /* Get wrap NID */ 936 ctx = CMS_RecipientInfo_kari_get0_ctx(ri); 937 wrap_nid = EVP_CIPHER_CTX_type(ctx); 938 keylen = EVP_CIPHER_CTX_key_length(ctx); 939 940 /* Package wrap algorithm in an AlgorithmIdentifier */ 941 942 wrap_alg = X509_ALGOR_new(); 943 if (wrap_alg == NULL) 944 goto err; 945 wrap_alg->algorithm = OBJ_nid2obj(wrap_nid); 946 wrap_alg->parameter = ASN1_TYPE_new(); 947 if (wrap_alg->parameter == NULL) 948 goto err; 949 if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0) 950 goto err; 951 if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) { 952 ASN1_TYPE_free(wrap_alg->parameter); 953 wrap_alg->parameter = NULL; 954 } 955 956 if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0) 957 goto err; 958 959 penclen = CMS_SharedInfo_encode(&penc, wrap_alg, ukm, keylen); 960 if (!penclen) 961 goto err; 962 963 if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, penc, penclen) <= 0) 964 goto err; 965 penc = NULL; 966 967 /* 968 * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter 969 * of another AlgorithmIdentifier. 970 */ 971 penclen = i2d_X509_ALGOR(wrap_alg, &penc); 972 if (!penc || !penclen) 973 goto err; 974 wrap_str = ASN1_STRING_new(); 975 if (wrap_str == NULL) 976 goto err; 977 ASN1_STRING_set0(wrap_str, penc, penclen); 978 penc = NULL; 979 X509_ALGOR_set0(talg, OBJ_nid2obj(kdf_nid), V_ASN1_SEQUENCE, wrap_str); 980 981 rv = 1; 982 983 err: 984 free(penc); 985 X509_ALGOR_free(wrap_alg); 986 return rv; 987 } 988 989 #endif 990 991 const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = { 992 .pkey_id = EVP_PKEY_EC, 993 .pkey_base_id = EVP_PKEY_EC, 994 995 .pem_str = "EC", 996 .info = "OpenSSL EC algorithm", 997 998 .pub_decode = eckey_pub_decode, 999 .pub_encode = eckey_pub_encode, 1000 .pub_cmp = eckey_pub_cmp, 1001 .pub_print = eckey_pub_print, 1002 1003 .priv_decode = eckey_priv_decode, 1004 .priv_encode = eckey_priv_encode, 1005 .priv_print = eckey_priv_print, 1006 1007 .pkey_size = int_ec_size, 1008 .pkey_bits = ec_bits, 1009 1010 .param_decode = eckey_param_decode, 1011 .param_encode = eckey_param_encode, 1012 .param_missing = ec_missing_parameters, 1013 .param_copy = ec_copy_parameters, 1014 .param_cmp = ec_cmp_parameters, 1015 .param_print = eckey_param_print, 1016 1017 .pkey_free = int_ec_free, 1018 .pkey_ctrl = ec_pkey_ctrl, 1019 .old_priv_decode = old_ec_priv_decode, 1020 .old_priv_encode = old_ec_priv_encode, 1021 1022 .pkey_check = ec_pkey_check, 1023 .pkey_public_check = ec_pkey_public_check, 1024 .pkey_param_check = ec_pkey_param_check, 1025 }; 1026