lib/libcrypto/ec/ec_ameth.c

   1 /* $OpenBSD: ec_ameth.c,v 1.18 2017/01/29 17:49:23 beck 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/ec.h>
  65 #include <openssl/err.h>
  66 #include <openssl/x509.h>
  67
  68
  69 #include "asn1_locl.h"
  70
  71 static int
  72 eckey_param2type(int *pptype, void **ppval, EC_KEY * ec_key)
  73 {
  74         const EC_GROUP *group;
  75         int nid;
  76         if (ec_key == NULL || (group = EC_KEY_get0_group(ec_key)) == NULL) {
  77                 ECerror(EC_R_MISSING_PARAMETERS);
  78                 return 0;
  79         }
  80         if (EC_GROUP_get_asn1_flag(group) &&
  81             (nid = EC_GROUP_get_curve_name(group))) {
  82                 /* we have a 'named curve' => just set the OID */
  83                 *ppval = OBJ_nid2obj(nid);
  84                 *pptype = V_ASN1_OBJECT;
  85         } else {
  86                 /* explicit parameters */
  87                 ASN1_STRING *pstr = NULL;
  88                 pstr = ASN1_STRING_new();
  89                 if (!pstr)
  90                         return 0;
  91                 pstr->length = i2d_ECParameters(ec_key, &pstr->data);
  92                 if (pstr->length <= 0) {
  93                         ASN1_STRING_free(pstr);
  94                         ECerror(ERR_R_EC_LIB);
  95                         return 0;
  96                 }
  97                 *ppval = pstr;
  98                 *pptype = V_ASN1_SEQUENCE;
  99         }
 100         return 1;
 101 }
 102
 103 static int
 104 eckey_pub_encode(X509_PUBKEY * pk, const EVP_PKEY * pkey)
 105 {
 106         EC_KEY *ec_key = pkey->pkey.ec;
 107         void *pval = NULL;
 108         int ptype;
 109         unsigned char *penc = NULL, *p;
 110         int penclen;
 111
 112         if (!eckey_param2type(&ptype, &pval, ec_key)) {
 113                 ECerror(ERR_R_EC_LIB);
 114                 return 0;
 115         }
 116         penclen = i2o_ECPublicKey(ec_key, NULL);
 117         if (penclen <= 0)
 118                 goto err;
 119         penc = malloc(penclen);
 120         if (!penc)
 121                 goto err;
 122         p = penc;
 123         penclen = i2o_ECPublicKey(ec_key, &p);
 124         if (penclen <= 0)
 125                 goto err;
 126         if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(EVP_PKEY_EC),
 127                 ptype, pval, penc, penclen))
 128                 return 1;
 129 err:
 130         if (ptype == V_ASN1_OBJECT)
 131                 ASN1_OBJECT_free(pval);
 132         else
 133                 ASN1_STRING_free(pval);
 134         free(penc);
 135         return 0;
 136 }
 137
 138 static EC_KEY *
 139 eckey_type2param(int ptype, void *pval)
 140 {
 141         EC_KEY *eckey = NULL;
 142
 143         if (ptype == V_ASN1_SEQUENCE) {
 144                 ASN1_STRING *pstr = pval;
 145                 const unsigned char *pm = NULL;
 146                 int pmlen;
 147
 148                 pm = pstr->data;
 149                 pmlen = pstr->length;
 150                 if (!(eckey = d2i_ECParameters(NULL, &pm, pmlen))) {
 151                         ECerror(EC_R_DECODE_ERROR);
 152                         goto ecerr;
 153                 }
 154         } else if (ptype == V_ASN1_OBJECT) {
 155                 ASN1_OBJECT *poid = pval;
 156                 EC_GROUP *group;
 157
 158                 /*
 159                  * type == V_ASN1_OBJECT => the parameters are given by an
 160                  * asn1 OID
 161                  */
 162                 if ((eckey = EC_KEY_new()) == NULL) {
 163                         ECerror(ERR_R_MALLOC_FAILURE);
 164                         goto ecerr;
 165                 }
 166                 group = EC_GROUP_new_by_curve_name(OBJ_obj2nid(poid));
 167                 if (group == NULL)
 168                         goto ecerr;
 169                 EC_GROUP_set_asn1_flag(group, OPENSSL_EC_NAMED_CURVE);
 170                 if (EC_KEY_set_group(eckey, group) == 0)
 171                         goto ecerr;
 172                 EC_GROUP_free(group);
 173         } else {
 174                 ECerror(EC_R_DECODE_ERROR);
 175                 goto ecerr;
 176         }
 177
 178         return eckey;
 179
 180 ecerr:
 181         if (eckey)
 182                 EC_KEY_free(eckey);
 183         return NULL;
 184 }
 185
 186 static int
 187 eckey_pub_decode(EVP_PKEY * pkey, X509_PUBKEY * pubkey)
 188 {
 189         const unsigned char *p = NULL;
 190         void *pval;
 191         int ptype, pklen;
 192         EC_KEY *eckey = NULL;
 193         X509_ALGOR *palg;
 194
 195         if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
 196                 return 0;
 197         X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 198
 199         eckey = eckey_type2param(ptype, pval);
 200
 201         if (!eckey) {
 202                 ECerror(ERR_R_EC_LIB);
 203                 return 0;
 204         }
 205         /* We have parameters now set public key */
 206         if (!o2i_ECPublicKey(&eckey, &p, pklen)) {
 207                 ECerror(EC_R_DECODE_ERROR);
 208                 goto ecerr;
 209         }
 210         EVP_PKEY_assign_EC_KEY(pkey, eckey);
 211         return 1;
 212
 213 ecerr:
 214         if (eckey)
 215                 EC_KEY_free(eckey);
 216         return 0;
 217 }
 218
 219 static int
 220 eckey_pub_cmp(const EVP_PKEY * a, const EVP_PKEY * b)
 221 {
 222         int r;
 223         const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec);
 224         const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec), *pb = EC_KEY_get0_public_key(b->pkey.ec);
 225
 226         r = EC_POINT_cmp(group, pa, pb, NULL);
 227         if (r == 0)
 228                 return 1;
 229         if (r == 1)
 230                 return 0;
 231         return -2;
 232 }
 233
 234 static int
 235 eckey_priv_decode(EVP_PKEY * pkey, PKCS8_PRIV_KEY_INFO * p8)
 236 {
 237         const unsigned char *p = NULL;
 238         void *pval;
 239         int ptype, pklen;
 240         EC_KEY *eckey = NULL;
 241         X509_ALGOR *palg;
 242
 243         if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 244                 return 0;
 245         X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 246
 247         eckey = eckey_type2param(ptype, pval);
 248
 249         if (!eckey)
 250                 goto ecliberr;
 251
 252         /* We have parameters now set private key */
 253         if (!d2i_ECPrivateKey(&eckey, &p, pklen)) {
 254                 ECerror(EC_R_DECODE_ERROR);
 255                 goto ecerr;
 256         }
 257         /* calculate public key (if necessary) */
 258         if (EC_KEY_get0_public_key(eckey) == NULL) {
 259                 const BIGNUM *priv_key;
 260                 const EC_GROUP *group;
 261                 EC_POINT *pub_key;
 262                 /*
 263                  * the public key was not included in the SEC1 private key =>
 264                  * calculate the public key
 265                  */
 266                 group = EC_KEY_get0_group(eckey);
 267                 pub_key = EC_POINT_new(group);
 268                 if (pub_key == NULL) {
 269                         ECerror(ERR_R_EC_LIB);
 270                         goto ecliberr;
 271                 }
 272                 if (!EC_POINT_copy(pub_key, EC_GROUP_get0_generator(group))) {
 273                         EC_POINT_free(pub_key);
 274                         ECerror(ERR_R_EC_LIB);
 275                         goto ecliberr;
 276                 }
 277                 priv_key = EC_KEY_get0_private_key(eckey);
 278                 if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, NULL)) {
 279                         EC_POINT_free(pub_key);
 280                         ECerror(ERR_R_EC_LIB);
 281                         goto ecliberr;
 282                 }
 283                 if (EC_KEY_set_public_key(eckey, pub_key) == 0) {
 284                         EC_POINT_free(pub_key);
 285                         ECerror(ERR_R_EC_LIB);
 286                         goto ecliberr;
 287                 }
 288                 EC_POINT_free(pub_key);
 289         }
 290         EVP_PKEY_assign_EC_KEY(pkey, eckey);
 291         return 1;
 292
 293 ecliberr:
 294         ECerror(ERR_R_EC_LIB);
 295 ecerr:
 296         if (eckey)
 297                 EC_KEY_free(eckey);
 298         return 0;
 299 }
 300
 301 static int
 302 eckey_priv_encode(PKCS8_PRIV_KEY_INFO * p8, const EVP_PKEY * pkey)
 303 {
 304         EC_KEY *ec_key;
 305         unsigned char *ep, *p;
 306         int eplen, ptype;
 307         void *pval;
 308         unsigned int tmp_flags, old_flags;
 309
 310         ec_key = pkey->pkey.ec;
 311
 312         if (!eckey_param2type(&ptype, &pval, ec_key)) {
 313                 ECerror(EC_R_DECODE_ERROR);
 314                 return 0;
 315         }
 316         /* set the private key */
 317
 318         /*
 319          * do not include the parameters in the SEC1 private key see PKCS#11
 320          * 12.11
 321          */
 322         old_flags = EC_KEY_get_enc_flags(ec_key);
 323         tmp_flags = old_flags | EC_PKEY_NO_PARAMETERS;
 324         EC_KEY_set_enc_flags(ec_key, tmp_flags);
 325         eplen = i2d_ECPrivateKey(ec_key, NULL);
 326         if (!eplen) {
 327                 EC_KEY_set_enc_flags(ec_key, old_flags);
 328                 ECerror(ERR_R_EC_LIB);
 329                 return 0;
 330         }
 331         ep = malloc(eplen);
 332         if (!ep) {
 333                 EC_KEY_set_enc_flags(ec_key, old_flags);
 334                 ECerror(ERR_R_MALLOC_FAILURE);
 335                 return 0;
 336         }
 337         p = ep;
 338         if (!i2d_ECPrivateKey(ec_key, &p)) {
 339                 EC_KEY_set_enc_flags(ec_key, old_flags);
 340                 free(ep);
 341                 ECerror(ERR_R_EC_LIB);
 342                 return 0;
 343         }
 344         /* restore old encoding flags */
 345         EC_KEY_set_enc_flags(ec_key, old_flags);
 346
 347         if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0,
 348                 ptype, pval, ep, eplen))
 349                 return 0;
 350
 351         return 1;
 352 }
 353
 354 static int
 355 int_ec_size(const EVP_PKEY * pkey)
 356 {
 357         return ECDSA_size(pkey->pkey.ec);
 358 }
 359
 360 static int
 361 ec_bits(const EVP_PKEY * pkey)
 362 {
 363         BIGNUM *order = BN_new();
 364         const EC_GROUP *group;
 365         int ret;
 366
 367         if (!order) {
 368                 ERR_clear_error();
 369                 return 0;
 370         }
 371         group = EC_KEY_get0_group(pkey->pkey.ec);
 372         if (!EC_GROUP_get_order(group, order, NULL)) {
 373                 BN_free(order);
 374                 ERR_clear_error();
 375                 return 0;
 376         }
 377         ret = BN_num_bits(order);
 378         BN_free(order);
 379         return ret;
 380 }
 381
 382 static int
 383 ec_missing_parameters(const EVP_PKEY * pkey)
 384 {
 385         if (EC_KEY_get0_group(pkey->pkey.ec) == NULL)
 386                 return 1;
 387         return 0;
 388 }
 389
 390 static int
 391 ec_copy_parameters(EVP_PKEY * to, const EVP_PKEY * from)
 392 {
 393         return EC_KEY_set_group(to->pkey.ec, EC_KEY_get0_group(from->pkey.ec));
 394 }
 395
 396 static int
 397 ec_cmp_parameters(const EVP_PKEY * a, const EVP_PKEY * b)
 398 {
 399         const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec), *group_b = EC_KEY_get0_group(b->pkey.ec);
 400         if (EC_GROUP_cmp(group_a, group_b, NULL))
 401                 return 0;
 402         else
 403                 return 1;
 404 }
 405
 406 static void
 407 int_ec_free(EVP_PKEY * pkey)
 408 {
 409         EC_KEY_free(pkey->pkey.ec);
 410 }
 411
 412 static int
 413 do_EC_KEY_print(BIO * bp, const EC_KEY * x, int off, int ktype)
 414 {
 415         unsigned char *buffer = NULL;
 416         const char *ecstr;
 417         size_t buf_len = 0, i;
 418         int ret = 0, reason = ERR_R_BIO_LIB;
 419         BIGNUM *pub_key = NULL, *order = NULL;
 420         BN_CTX *ctx = NULL;
 421         const EC_GROUP *group;
 422         const EC_POINT *public_key;
 423         const BIGNUM *priv_key;
 424
 425         if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL) {
 426                 reason = ERR_R_PASSED_NULL_PARAMETER;
 427                 goto err;
 428         }
 429         ctx = BN_CTX_new();
 430         if (ctx == NULL) {
 431                 reason = ERR_R_MALLOC_FAILURE;
 432                 goto err;
 433         }
 434         if (ktype > 0) {
 435                 public_key = EC_KEY_get0_public_key(x);
 436                 if ((pub_key = EC_POINT_point2bn(group, public_key,
 437                             EC_KEY_get_conv_form(x), NULL, ctx)) == NULL) {
 438                         reason = ERR_R_EC_LIB;
 439                         goto err;
 440                 }
 441                 if (pub_key)
 442                         buf_len = (size_t) BN_num_bytes(pub_key);
 443         }
 444         if (ktype == 2) {
 445                 priv_key = EC_KEY_get0_private_key(x);
 446                 if (priv_key && (i = (size_t) BN_num_bytes(priv_key)) > buf_len)
 447                         buf_len = i;
 448         } else
 449                 priv_key = NULL;
 450
 451         if (ktype > 0) {
 452                 buf_len += 10;
 453                 if ((buffer = malloc(buf_len)) == NULL) {
 454                         reason = ERR_R_MALLOC_FAILURE;
 455                         goto err;
 456                 }
 457         }
 458         if (ktype == 2)
 459                 ecstr = "Private-Key";
 460         else if (ktype == 1)
 461                 ecstr = "Public-Key";
 462         else
 463                 ecstr = "ECDSA-Parameters";
 464
 465         if (!BIO_indent(bp, off, 128))
 466                 goto err;
 467         if ((order = BN_new()) == NULL)
 468                 goto err;
 469         if (!EC_GROUP_get_order(group, order, NULL))
 470                 goto err;
 471         if (BIO_printf(bp, "%s: (%d bit)\n", ecstr,
 472                 BN_num_bits(order)) <= 0)
 473                 goto err;
 474
 475         if ((priv_key != NULL) && !ASN1_bn_print(bp, "priv:", priv_key,
 476                 buffer, off))
 477                 goto err;
 478         if ((pub_key != NULL) && !ASN1_bn_print(bp, "pub: ", pub_key,
 479                 buffer, off))
 480                 goto err;
 481         if (!ECPKParameters_print(bp, group, off))
 482                 goto err;
 483         ret = 1;
 484 err:
 485         if (!ret)
 486                 ECerror(reason);
 487         BN_free(pub_key);
 488         BN_free(order);
 489         BN_CTX_free(ctx);
 490         free(buffer);
 491         return (ret);
 492 }
 493
 494 static int
 495 eckey_param_decode(EVP_PKEY * pkey,
 496     const unsigned char **pder, int derlen)
 497 {
 498         EC_KEY *eckey;
 499         if (!(eckey = d2i_ECParameters(NULL, pder, derlen))) {
 500                 ECerror(ERR_R_EC_LIB);
 501                 return 0;
 502         }
 503         EVP_PKEY_assign_EC_KEY(pkey, eckey);
 504         return 1;
 505 }
 506
 507 static int
 508 eckey_param_encode(const EVP_PKEY * pkey, unsigned char **pder)
 509 {
 510         return i2d_ECParameters(pkey->pkey.ec, pder);
 511 }
 512
 513 static int
 514 eckey_param_print(BIO * bp, const EVP_PKEY * pkey, int indent,
 515     ASN1_PCTX * ctx)
 516 {
 517         return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 0);
 518 }
 519
 520 static int
 521 eckey_pub_print(BIO * bp, const EVP_PKEY * pkey, int indent,
 522     ASN1_PCTX * ctx)
 523 {
 524         return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 1);
 525 }
 526
 527
 528 static int
 529 eckey_priv_print(BIO * bp, const EVP_PKEY * pkey, int indent,
 530     ASN1_PCTX * ctx)
 531 {
 532         return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 2);
 533 }
 534
 535 static int
 536 old_ec_priv_decode(EVP_PKEY * pkey,
 537     const unsigned char **pder, int derlen)
 538 {
 539         EC_KEY *ec;
 540         if (!(ec = d2i_ECPrivateKey(NULL, pder, derlen))) {
 541                 ECerror(EC_R_DECODE_ERROR);
 542                 return 0;
 543         }
 544         EVP_PKEY_assign_EC_KEY(pkey, ec);
 545         return 1;
 546 }
 547
 548 static int
 549 old_ec_priv_encode(const EVP_PKEY * pkey, unsigned char **pder)
 550 {
 551         return i2d_ECPrivateKey(pkey->pkey.ec, pder);
 552 }
 553
 554 static int
 555 ec_pkey_ctrl(EVP_PKEY * pkey, int op, long arg1, void *arg2)
 556 {
 557         switch (op) {
 558         case ASN1_PKEY_CTRL_PKCS7_SIGN:
 559                 if (arg1 == 0) {
 560                         int snid, hnid;
 561                         X509_ALGOR *alg1, *alg2;
 562                         PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2);
 563                         if (alg1 == NULL || alg1->algorithm == NULL)
 564                                 return -1;
 565                         hnid = OBJ_obj2nid(alg1->algorithm);
 566                         if (hnid == NID_undef)
 567                                 return -1;
 568                         if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 569                                 return -1;
 570                         X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 571                 }
 572                 return 1;
 573
 574         case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
 575                 *(int *) arg2 = NID_sha1;
 576                 return 2;
 577
 578         default:
 579                 return -2;
 580
 581         }
 582
 583 }
 584
 585 const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = {
 586         .pkey_id = EVP_PKEY_EC,
 587         .pkey_base_id = EVP_PKEY_EC,
 588
 589         .pem_str = "EC",
 590         .info = "OpenSSL EC algorithm",
 591
 592         .pub_decode = eckey_pub_decode,
 593         .pub_encode = eckey_pub_encode,
 594         .pub_cmp = eckey_pub_cmp,
 595         .pub_print = eckey_pub_print,
 596
 597         .priv_decode = eckey_priv_decode,
 598         .priv_encode = eckey_priv_encode,
 599         .priv_print = eckey_priv_print,
 600
 601         .pkey_size = int_ec_size,
 602         .pkey_bits = ec_bits,
 603
 604         .param_decode = eckey_param_decode,
 605         .param_encode = eckey_param_encode,
 606         .param_missing = ec_missing_parameters,
 607         .param_copy = ec_copy_parameters,
 608         .param_cmp = ec_cmp_parameters,
 609         .param_print = eckey_param_print,
 610
 611         .pkey_free = int_ec_free,
 612         .pkey_ctrl = ec_pkey_ctrl,
 613         .old_priv_decode = old_ec_priv_decode,
 614         .old_priv_encode = old_ec_priv_encode
 615 };