crypto/ec/ec_ameth.c

   1 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   2  * project 2006.
   3  */
   4 /* ====================================================================
   5  * Copyright (c) 2006 The OpenSSL Project.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  *
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  *
  19  * 3. All advertising materials mentioning features or use of this
  20  *    software must display the following acknowledgment:
  21  *    "This product includes software developed by the OpenSSL Project
  22  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  23  *
  24  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  25  *    endorse or promote products derived from this software without
  26  *    prior written permission. For written permission, please contact
  27  *    licensing@OpenSSL.org.
  28  *
  29  * 5. Products derived from this software may not be called "OpenSSL"
  30  *    nor may "OpenSSL" appear in their names without prior written
  31  *    permission of the OpenSSL Project.
  32  *
  33  * 6. Redistributions of any form whatsoever must retain the following
  34  *    acknowledgment:
  35  *    "This product includes software developed by the OpenSSL Project
  36  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  37  *
  38  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  39  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  40  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  41  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  42  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  43  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  44  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  45  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  46  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  47  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  48  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  49  * OF THE POSSIBILITY OF SUCH DAMAGE.
  50  * ====================================================================
  51  *
  52  * This product includes cryptographic software written by Eric Young
  53  * (eay@cryptsoft.com).  This product includes software written by Tim
  54  * Hudson (tjh@cryptsoft.com).
  55  *
  56  */
  57
  58 #include <stdio.h>
  59 #include "cryptlib.h"
  60 #include <openssl/x509.h>
  61 #include <openssl/ec.h>
  62 #include <openssl/bn.h>
  63 #ifndef OPENSSL_NO_CMS
  64 #include <openssl/cms.h>
  65 #endif
  66 #include <openssl/asn1t.h>
  67 #include "asn1_locl.h"
  68
  69 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri);
  70 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri);
  71
  72 static int 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         {
  78                 ECerr(EC_F_ECKEY_PARAM2TYPE, EC_R_MISSING_PARAMETERS);
  79                 return 0;
  80         }
  81         if (EC_GROUP_get_asn1_flag(group)
  82                      && (nid = EC_GROUP_get_curve_name(group)))
  83                 /* we have a 'named curve' => just set the OID */
  84                 {
  85                 *ppval = OBJ_nid2obj(nid);
  86                 *pptype = V_ASN1_OBJECT;
  87                 }
  88         else    /* explicit parameters */
  89                 {
  90                 ASN1_STRING *pstr = NULL;
  91                 pstr = ASN1_STRING_new();
  92                 if (!pstr)
  93                         return 0;
  94                 pstr->length = i2d_ECParameters(ec_key, &pstr->data);
  95                 if (pstr->length <= 0)
  96                         {
  97                         ASN1_STRING_free(pstr);
  98                         ECerr(EC_F_ECKEY_PARAM2TYPE, ERR_R_EC_LIB);
  99                         return 0;
 100                         }
 101                 *ppval = pstr;
 102                 *pptype = V_ASN1_SEQUENCE;
 103                 }
 104         return 1;
 105         }
 106
 107 static int eckey_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 108         {
 109         EC_KEY *ec_key = pkey->pkey.ec;
 110         void *pval = NULL;
 111         int ptype;
 112         unsigned char *penc = NULL, *p;
 113         int penclen;
 114
 115         if (!eckey_param2type(&ptype, &pval, ec_key))
 116                 {
 117                 ECerr(EC_F_ECKEY_PUB_ENCODE, ERR_R_EC_LIB);
 118                 return 0;
 119                 }
 120         penclen = i2o_ECPublicKey(ec_key, NULL);
 121         if (penclen <= 0)
 122                 goto err;
 123         penc = OPENSSL_malloc(penclen);
 124         if (!penc)
 125                 goto err;
 126         p = penc;
 127         penclen = i2o_ECPublicKey(ec_key, &p);
 128         if (penclen <= 0)
 129                 goto err;
 130         if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(EVP_PKEY_EC),
 131                                 ptype, pval, penc, penclen))
 132                 return 1;
 133         err:
 134         if (ptype == V_ASN1_OBJECT)
 135                 ASN1_OBJECT_free(pval);
 136         else
 137                 ASN1_STRING_free(pval);
 138         if (penc)
 139                 OPENSSL_free(penc);
 140         return 0;
 141         }
 142
 143 static EC_KEY *eckey_type2param(int ptype, void *pval)
 144         {
 145         EC_KEY *eckey = NULL;
 146         if (ptype == V_ASN1_SEQUENCE)
 147                 {
 148                 ASN1_STRING *pstr = pval;
 149                 const unsigned char *pm = NULL;
 150                 int pmlen;
 151                 pm = pstr->data;
 152                 pmlen = pstr->length;
 153                 if (!(eckey = d2i_ECParameters(NULL, &pm, pmlen)))
 154                         {
 155                         ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
 156                         goto ecerr;
 157                         }
 158                 }
 159         else if (ptype == V_ASN1_OBJECT)
 160                 {
 161                 ASN1_OBJECT *poid = pval;
 162                 EC_GROUP *group;
 163
 164                 /* type == V_ASN1_OBJECT => the parameters are given
 165                  * by an asn1 OID
 166                  */
 167                 if ((eckey = EC_KEY_new()) == NULL)
 168                         {
 169                         ECerr(EC_F_ECKEY_TYPE2PARAM, ERR_R_MALLOC_FAILURE);
 170                         goto ecerr;
 171                         }
 172                 group = EC_GROUP_new_by_curve_name(OBJ_obj2nid(poid));
 173                 if (group == NULL)
 174                         goto ecerr;
 175                 EC_GROUP_set_asn1_flag(group, OPENSSL_EC_NAMED_CURVE);
 176                 if (EC_KEY_set_group(eckey, group) == 0)
 177                         goto ecerr;
 178                 EC_GROUP_free(group);
 179                 }
 180         else
 181                 {
 182                 ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
 183                 goto ecerr;
 184                 }
 185
 186         return eckey;
 187
 188         ecerr:
 189         if (eckey)
 190                 EC_KEY_free(eckey);
 191         return NULL;
 192         }
 193
 194 static int eckey_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
 195         {
 196         const unsigned char *p = NULL;
 197         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                 {
 210                 ECerr(EC_F_ECKEY_PUB_DECODE, ERR_R_EC_LIB);
 211                 return 0;
 212                 }
 213
 214         /* We have parameters now set public key */
 215         if (!o2i_ECPublicKey(&eckey, &p, pklen))
 216                 {
 217                 ECerr(EC_F_ECKEY_PUB_DECODE, EC_R_DECODE_ERROR);
 218                 goto ecerr;
 219                 }
 220
 221         EVP_PKEY_assign_EC_KEY(pkey, eckey);
 222         return 1;
 223
 224         ecerr:
 225         if (eckey)
 226                 EC_KEY_free(eckey);
 227         return 0;
 228         }
 229
 230 static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 231         {
 232         int  r;
 233         const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec);
 234         const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec),
 235                        *pb = EC_KEY_get0_public_key(b->pkey.ec);
 236         r = EC_POINT_cmp(group, pa, pb, NULL);
 237         if (r == 0)
 238                 return 1;
 239         if (r == 1)
 240                 return 0;
 241         return -2;
 242         }
 243
 244 static int eckey_priv_decode(EVP_PKEY *pkey, PKCS8_PRIV_KEY_INFO *p8)
 245         {
 246         const unsigned char *p = NULL;
 247         void *pval;
 248         int ptype, pklen;
 249         EC_KEY *eckey = NULL;
 250         X509_ALGOR *palg;
 251
 252         if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 253                 return 0;
 254         X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 255
 256         eckey = eckey_type2param(ptype, pval);
 257
 258         if (!eckey)
 259                 goto ecliberr;
 260
 261         /* We have parameters now set private key */
 262         if (!d2i_ECPrivateKey(&eckey, &p, pklen))
 263                 {
 264                 ECerr(EC_F_ECKEY_PRIV_DECODE, EC_R_DECODE_ERROR);
 265                 goto ecerr;
 266                 }
 267
 268         /* calculate public key (if necessary) */
 269         if (EC_KEY_get0_public_key(eckey) == NULL)
 270                 {
 271                 const BIGNUM *priv_key;
 272                 const EC_GROUP *group;
 273                 EC_POINT *pub_key;
 274                 /* the public key was not included in the SEC1 private
 275                  * key => calculate the public key */
 276                 group   = EC_KEY_get0_group(eckey);
 277                 pub_key = EC_POINT_new(group);
 278                 if (pub_key == NULL)
 279                         {
 280                         ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 281                         goto ecliberr;
 282                         }
 283                 if (!EC_POINT_copy(pub_key, EC_GROUP_get0_generator(group)))
 284                         {
 285                         EC_POINT_free(pub_key);
 286                         ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 287                         goto ecliberr;
 288                         }
 289                 priv_key = EC_KEY_get0_private_key(eckey);
 290                 if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, NULL))
 291                         {
 292                         EC_POINT_free(pub_key);
 293                         ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 294                         goto ecliberr;
 295                         }
 296                 if (EC_KEY_set_public_key(eckey, pub_key) == 0)
 297                         {
 298                         EC_POINT_free(pub_key);
 299                         ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 300                         goto ecliberr;
 301                         }
 302                 EC_POINT_free(pub_key);
 303                 }
 304
 305         EVP_PKEY_assign_EC_KEY(pkey, eckey);
 306         return 1;
 307
 308         ecliberr:
 309         ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 310         ecerr:
 311         if (eckey)
 312                 EC_KEY_free(eckey);
 313         return 0;
 314         }
 315
 316 static int eckey_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 317 {
 318         EC_KEY          *ec_key;
 319         unsigned char   *ep, *p;
 320         int             eplen, ptype;
 321         void            *pval;
 322         unsigned int    tmp_flags, old_flags;
 323
 324         ec_key = pkey->pkey.ec;
 325
 326         if (!eckey_param2type(&ptype, &pval, ec_key))
 327                 {
 328                 ECerr(EC_F_ECKEY_PRIV_ENCODE, EC_R_DECODE_ERROR);
 329                 return 0;
 330                 }
 331
 332         /* set the private key */
 333
 334         /* do not include the parameters in the SEC1 private key
 335          * see PKCS#11 12.11 */
 336         old_flags = EC_KEY_get_enc_flags(ec_key);
 337         tmp_flags = old_flags | EC_PKEY_NO_PARAMETERS;
 338         EC_KEY_set_enc_flags(ec_key, tmp_flags);
 339         eplen = i2d_ECPrivateKey(ec_key, NULL);
 340         if (!eplen)
 341         {
 342                 EC_KEY_set_enc_flags(ec_key, old_flags);
 343                 ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
 344                 return 0;
 345         }
 346         ep = (unsigned char *) OPENSSL_malloc(eplen);
 347         if (!ep)
 348         {
 349                 EC_KEY_set_enc_flags(ec_key, old_flags);
 350                 ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 351                 return 0;
 352         }
 353         p = ep;
 354         if (!i2d_ECPrivateKey(ec_key, &p))
 355         {
 356                 EC_KEY_set_enc_flags(ec_key, old_flags);
 357                 OPENSSL_free(ep);
 358                 ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
 359         }
 360         /* restore old encoding flags */
 361         EC_KEY_set_enc_flags(ec_key, old_flags);
 362
 363         if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0,
 364                                 ptype, pval, ep, eplen))
 365                 return 0;
 366
 367         return 1;
 368 }
 369
 370 static int int_ec_size(const EVP_PKEY *pkey)
 371         {
 372         return ECDSA_size(pkey->pkey.ec);
 373         }
 374
 375 static int ec_bits(const EVP_PKEY *pkey)
 376         {
 377         BIGNUM *order = BN_new();
 378         const EC_GROUP *group;
 379         int ret;
 380
 381         if (!order)
 382                 {
 383                 ERR_clear_error();
 384                 return 0;
 385                 }
 386         group = EC_KEY_get0_group(pkey->pkey.ec);
 387         if (!EC_GROUP_get_order(group, order, NULL))
 388                 {
 389                 ERR_clear_error();
 390                 return 0;
 391                 }
 392
 393         ret = BN_num_bits(order);
 394         BN_free(order);
 395         return ret;
 396         }
 397
 398 static int ec_missing_parameters(const EVP_PKEY *pkey)
 399         {
 400         if (EC_KEY_get0_group(pkey->pkey.ec) == NULL)
 401                 return 1;
 402         return 0;
 403         }
 404
 405 static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 406         {
 407         EC_GROUP *group = EC_GROUP_dup(EC_KEY_get0_group(from->pkey.ec));
 408         if (group == NULL)
 409                 return 0;
 410         if (EC_KEY_set_group(to->pkey.ec, group) == 0)
 411                 return 0;
 412         EC_GROUP_free(group);
 413         return 1;
 414         }
 415
 416 static int ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 417         {
 418         const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec),
 419                        *group_b = EC_KEY_get0_group(b->pkey.ec);
 420         if (EC_GROUP_cmp(group_a, group_b, NULL))
 421                 return 0;
 422         else
 423                 return 1;
 424         }
 425
 426 static void int_ec_free(EVP_PKEY *pkey)
 427         {
 428         EC_KEY_free(pkey->pkey.ec);
 429         }
 430
 431 static int do_EC_KEY_print(BIO *bp, const EC_KEY *x, int off, int ktype)
 432         {
 433         unsigned char *buffer=NULL;
 434         const char *ecstr;
 435         size_t  buf_len=0, i;
 436         int     ret=0, reason=ERR_R_BIO_LIB;
 437         BIGNUM  *pub_key=NULL, *order=NULL;
 438         BN_CTX  *ctx=NULL;
 439         const EC_GROUP *group;
 440         const EC_POINT *public_key;
 441         const BIGNUM *priv_key;
 442
 443         if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL)
 444                 {
 445                 reason = ERR_R_PASSED_NULL_PARAMETER;
 446                 goto err;
 447                 }
 448
 449         ctx = BN_CTX_new();
 450         if (ctx == NULL)
 451                 {
 452                 reason = ERR_R_MALLOC_FAILURE;
 453                 goto err;
 454                 }
 455
 456         if (ktype > 0)
 457                 {
 458                 public_key = EC_KEY_get0_public_key(x);
 459                 if ((pub_key = EC_POINT_point2bn(group, public_key,
 460                         EC_KEY_get_conv_form(x), NULL, ctx)) == NULL)
 461                         {
 462                         reason = ERR_R_EC_LIB;
 463                         goto err;
 464                         }
 465                 if (pub_key)
 466                         buf_len = (size_t)BN_num_bytes(pub_key);
 467                 }
 468
 469         if (ktype == 2)
 470                 {
 471                 priv_key = EC_KEY_get0_private_key(x);
 472                 if (priv_key && (i = (size_t)BN_num_bytes(priv_key)) > buf_len)
 473                         buf_len = i;
 474                 }
 475         else
 476                 priv_key = NULL;
 477
 478         if (ktype > 0)
 479                 {
 480                 buf_len += 10;
 481                 if ((buffer = OPENSSL_malloc(buf_len)) == NULL)
 482                         {
 483                         reason = ERR_R_MALLOC_FAILURE;
 484                         goto err;
 485                         }
 486                 }
 487         if (ktype == 2)
 488                 ecstr = "Private-Key";
 489         else if (ktype == 1)
 490                 ecstr = "Public-Key";
 491         else
 492                 ecstr = "ECDSA-Parameters";
 493
 494         if (!BIO_indent(bp, off, 128))
 495                 goto err;
 496         if ((order = BN_new()) == NULL)
 497                 goto err;
 498         if (!EC_GROUP_get_order(group, order, NULL))
 499                 goto err;
 500         if (BIO_printf(bp, "%s: (%d bit)\n", ecstr,
 501                 BN_num_bits(order)) <= 0) goto err;
 502
 503         if ((priv_key != NULL) && !ASN1_bn_print(bp, "priv:", priv_key,
 504                 buffer, off))
 505                 goto err;
 506         if ((pub_key != NULL) && !ASN1_bn_print(bp, "pub: ", pub_key,
 507                 buffer, off))
 508                 goto err;
 509         if (!ECPKParameters_print(bp, group, off))
 510                 goto err;
 511         ret=1;
 512 err:
 513         if (!ret)
 514                 ECerr(EC_F_DO_EC_KEY_PRINT, reason);
 515         if (pub_key)
 516                 BN_free(pub_key);
 517         if (order)
 518                 BN_free(order);
 519         if (ctx)
 520                 BN_CTX_free(ctx);
 521         if (buffer != NULL)
 522                 OPENSSL_free(buffer);
 523         return(ret);
 524         }
 525
 526 static int eckey_param_decode(EVP_PKEY *pkey,
 527                                         const unsigned char **pder, int derlen)
 528         {
 529         EC_KEY *eckey;
 530         if (!(eckey = d2i_ECParameters(NULL, pder, derlen)))
 531                 {
 532                 ECerr(EC_F_ECKEY_PARAM_DECODE, ERR_R_EC_LIB);
 533                 return 0;
 534                 }
 535         EVP_PKEY_assign_EC_KEY(pkey, eckey);
 536         return 1;
 537         }
 538
 539 static int eckey_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 540         {
 541         return i2d_ECParameters(pkey->pkey.ec, pder);
 542         }
 543
 544 static int eckey_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 545                                                         ASN1_PCTX *ctx)
 546         {
 547         return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 0);
 548         }
 549
 550 static int eckey_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 551                                                         ASN1_PCTX *ctx)
 552         {
 553         return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 1);
 554         }
 555
 556
 557 static int eckey_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 558                                                         ASN1_PCTX *ctx)
 559         {
 560         return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 2);
 561         }
 562
 563 static int old_ec_priv_decode(EVP_PKEY *pkey,
 564                                         const unsigned char **pder, int derlen)
 565         {
 566         EC_KEY *ec;
 567         if (!(ec = d2i_ECPrivateKey (NULL, pder, derlen)))
 568                 {
 569                 ECerr(EC_F_OLD_EC_PRIV_DECODE, EC_R_DECODE_ERROR);
 570                 return 0;
 571                 }
 572         EVP_PKEY_assign_EC_KEY(pkey, ec);
 573         return 1;
 574         }
 575
 576 static int old_ec_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
 577         {
 578         return i2d_ECPrivateKey(pkey->pkey.ec, pder);
 579         }
 580
 581 static int ec_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 582         {
 583         switch (op)
 584                 {
 585                 case ASN1_PKEY_CTRL_PKCS7_SIGN:
 586                 if (arg1 == 0)
 587                         {
 588                         int snid, hnid;
 589                         X509_ALGOR *alg1, *alg2;
 590                         PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2);
 591                         if (alg1 == NULL || alg1->algorithm == NULL)
 592                                 return -1;
 593                         hnid = OBJ_obj2nid(alg1->algorithm);
 594                         if (hnid == NID_undef)
 595                                 return -1;
 596                         if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 597                                 return -1;
 598                         X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 599                         }
 600                 return 1;
 601 #ifndef OPENSSL_NO_CMS
 602                 case ASN1_PKEY_CTRL_CMS_SIGN:
 603                 if (arg1 == 0)
 604                         {
 605                         int snid, hnid;
 606                         X509_ALGOR *alg1, *alg2;
 607                         CMS_SignerInfo_get0_algs(arg2, NULL, NULL,
 608                                                                 &alg1, &alg2);
 609                         if (alg1 == NULL || alg1->algorithm == NULL)
 610                                 return -1;
 611                         hnid = OBJ_obj2nid(alg1->algorithm);
 612                         if (hnid == NID_undef)
 613                                 return -1;
 614                         if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 615                                 return -1;
 616                         X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 617                         }
 618                 return 1;
 619
 620                 case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 621                 if (arg1 == 1)
 622                         return ecdh_cms_decrypt(arg2);
 623                 else if (arg1 == 0)
 624                         return ecdh_cms_encrypt(arg2);
 625                 return -2;
 626
 627                 case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 628                 *(int *)arg2 = CMS_RECIPINFO_AGREE;
 629                 return 1;
 630 #endif
 631
 632                 case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
 633                 *(int *)arg2 = NID_sha1;
 634                 return 2;
 635
 636                 default:
 637                 return -2;
 638
 639                 }
 640
 641         }
 642
 643 const EVP_PKEY_ASN1_METHOD eckey_asn1_meth =
 644         {
 645         EVP_PKEY_EC,
 646         EVP_PKEY_EC,
 647         0,
 648         "EC",
 649         "OpenSSL EC algorithm",
 650
 651         eckey_pub_decode,
 652         eckey_pub_encode,
 653         eckey_pub_cmp,
 654         eckey_pub_print,
 655
 656         eckey_priv_decode,
 657         eckey_priv_encode,
 658         eckey_priv_print,
 659
 660         int_ec_size,
 661         ec_bits,
 662
 663         eckey_param_decode,
 664         eckey_param_encode,
 665         ec_missing_parameters,
 666         ec_copy_parameters,
 667         ec_cmp_parameters,
 668         eckey_param_print,
 669         0,
 670
 671         int_ec_free,
 672         ec_pkey_ctrl,
 673         old_ec_priv_decode,
 674         old_ec_priv_encode
 675         };
 676
 677 #ifndef OPENSSL_NO_CMS
 678
 679 static int ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 680                                 X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 681         {
 682         ASN1_OBJECT *aoid;
 683         int atype;
 684         void *aval;
 685         int rv = 0;
 686         EVP_PKEY *pkpeer = NULL;
 687         EC_KEY *ecpeer = NULL;
 688         const unsigned char *p;
 689         int plen;
 690         X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 691         if (OBJ_obj2nid(aoid) != NID_X9_62_id_ecPublicKey)
 692                 goto err;
 693         /* If absent parameters get group from main key */
 694         if (atype == V_ASN1_UNDEF || atype == V_ASN1_NULL)
 695                 {
 696                 const EC_GROUP *grp;
 697                 EVP_PKEY *pk;
 698                 pk = EVP_PKEY_CTX_get0_pkey(pctx);
 699                 if (!pk)
 700                         goto err;
 701                 grp = EC_KEY_get0_group(pk->pkey.ec);
 702                 ecpeer = EC_KEY_new();
 703                 if (!ecpeer)
 704                         goto err;
 705                 if (!EC_KEY_set_group(ecpeer, grp))
 706                         goto err;
 707                 }
 708         else
 709                 {
 710                 ecpeer = eckey_type2param(atype, aval);
 711                 if (!ecpeer)
 712                         goto err;
 713                 }
 714         /* We have parameters now set public key */
 715         plen = ASN1_STRING_length(pubkey);
 716         p = ASN1_STRING_data(pubkey);
 717         if (!p || !plen)
 718                 goto err;
 719         if (!o2i_ECPublicKey(&ecpeer, &p, plen))
 720                 goto err;
 721         pkpeer = EVP_PKEY_new();
 722         if (!pkpeer)
 723                 goto err;
 724         EVP_PKEY_set1_EC_KEY(pkpeer, ecpeer);
 725         if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 726                 rv = 1;
 727         err:
 728         if (ecpeer)
 729                 EC_KEY_free(ecpeer);
 730         if (pkpeer)
 731                 EVP_PKEY_free(pkpeer);
 732         return rv;
 733         }
 734 /* Set KDF parameters based on KDF NID */
 735 static int ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid)
 736         {
 737         int kdf_nid, kdfmd_nid, cofactor;
 738         const EVP_MD *kdf_md;
 739         if (eckdf_nid == NID_undef)
 740                 return 0;
 741
 742         /* Lookup KDF type, cofactor mode and digest */
 743         if (!OBJ_find_sigid_algs(eckdf_nid, &kdfmd_nid, &kdf_nid))
 744                 return 0;
 745
 746         if (kdf_nid == NID_dh_std_kdf)
 747                 cofactor = 0;
 748         else if (kdf_nid == NID_dh_cofactor_kdf)
 749                 cofactor = 1;
 750         else return 0;
 751
 752         if (EVP_PKEY_CTX_set_ecdh_cofactor_mode(pctx, cofactor) <= 0)
 753                 return 0;
 754
 755         if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, EVP_PKEY_ECDH_KDF_X9_62) <= 0)
 756                 return 0;
 757
 758         kdf_md = EVP_get_digestbynid(kdfmd_nid);
 759         if (!kdf_md)
 760                 return 0;
 761
 762         if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
 763                 return 0;
 764         return 1;
 765         }
 766
 767 /* Utilities to encode the ECC_CMS_SharedInfo structure used during key
 768  * derivation.
 769  */
 770
 771 typedef struct {
 772         X509_ALGOR *keyInfo;
 773         ASN1_OCTET_STRING *entityUInfo;
 774         ASN1_OCTET_STRING *suppPubInfo;
 775 } ECC_CMS_SharedInfo;
 776
 777 ASN1_SEQUENCE(ECC_CMS_SharedInfo) = {
 778   ASN1_SIMPLE(ECC_CMS_SharedInfo, keyInfo, X509_ALGOR),
 779   ASN1_EXP_OPT(ECC_CMS_SharedInfo, entityUInfo, ASN1_OCTET_STRING, 0),
 780   ASN1_EXP_OPT(ECC_CMS_SharedInfo, suppPubInfo, ASN1_OCTET_STRING, 2),
 781 } ASN1_SEQUENCE_END(ECC_CMS_SharedInfo)
 782
 783 static int ecdh_cms_set_ukm(EVP_PKEY_CTX *pctx,
 784                                         X509_ALGOR *kekalg,
 785                                         ASN1_OCTET_STRING *ukm,
 786                                         int keylen)
 787         {
 788         union {
 789                 ECC_CMS_SharedInfo *pecsi;
 790                 ASN1_VALUE *a;
 791         } intsi = {NULL};
 792
 793         unsigned char *der = NULL;
 794         int plen;
 795         ASN1_OCTET_STRING oklen;
 796         unsigned char kl[4];
 797         ECC_CMS_SharedInfo ecsi;
 798
 799         keylen <<= 3;
 800         kl[0] = (keylen >> 24) & 0xff;
 801         kl[1] = (keylen >> 16) & 0xff;
 802         kl[2] = (keylen >> 8) & 0xff;
 803         kl[3] = keylen & 0xff;
 804         oklen.length = 4;
 805         oklen.data = kl;
 806         oklen.type = V_ASN1_OCTET_STRING;
 807         oklen.flags = 0;
 808         ecsi.keyInfo = kekalg;
 809         ecsi.entityUInfo = ukm;
 810         ecsi.suppPubInfo = &oklen;
 811         intsi.pecsi = &ecsi;
 812         plen = ASN1_item_i2d(intsi.a, &der, ASN1_ITEM_rptr(ECC_CMS_SharedInfo));
 813         if (!der || !plen)
 814                 goto err;
 815         if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
 816                 goto err;
 817         return 1;
 818         err:
 819         if (der)
 820                 OPENSSL_free(der);
 821         return 0;
 822         }
 823
 824 static int ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 825         {
 826         int rv = 0;
 827
 828         X509_ALGOR *alg, *kekalg = NULL;
 829         ASN1_OCTET_STRING *ukm;
 830         const unsigned char *p;
 831         int plen, keylen;
 832         const EVP_CIPHER *kekcipher;
 833         EVP_CIPHER_CTX *kekctx;
 834
 835         if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 836                 return 0;
 837
 838         if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm)))
 839                 {
 840                 ECerr(EC_F_ECDH_CMS_SET_SHARED_INFO, EC_R_KDF_PARAMETER_ERROR);
 841                 return 0;
 842                 }
 843
 844         if (alg->parameter->type != V_ASN1_SEQUENCE)
 845                 return 0;
 846
 847         p = alg->parameter->value.sequence->data;
 848         plen = alg->parameter->value.sequence->length;
 849         kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 850         if (!kekalg)
 851                 goto err;
 852         kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 853         if (!kekctx)
 854                 goto err;
 855         kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 856         if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 857                 goto err;
 858         if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 859                 goto err;
 860
 861         keylen = EVP_CIPHER_CTX_key_length(kekctx);
 862         if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
 863                 goto err;
 864
 865         if (!ecdh_cms_set_ukm(pctx, kekalg, ukm, keylen))
 866                 goto err;
 867
 868         rv = 1;
 869         err:
 870         if (kekalg)
 871                 X509_ALGOR_free(kekalg);
 872         return rv;
 873         }
 874
 875 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri)
 876         {
 877         EVP_PKEY_CTX *pctx;
 878         pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 879         if (!pctx)
 880                 return 0;
 881         /* See if we need to set peer key */
 882         if (!EVP_PKEY_CTX_get0_peerkey(pctx))
 883                 {
 884                 X509_ALGOR *alg;
 885                 ASN1_BIT_STRING *pubkey;
 886                 if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 887                                                         NULL, NULL, NULL))
 888                         return 0;
 889                 if (!alg || !pubkey)
 890                         return 0;
 891                 if (!ecdh_cms_set_peerkey(pctx, alg, pubkey))
 892                         {
 893                         ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_PEER_KEY_ERROR);
 894                         return 0;
 895                         }
 896                 }
 897         /* Set ECDH derivation parameters and initialise unwrap context */
 898         if (!ecdh_cms_set_shared_info(pctx, ri))
 899                 {
 900                 ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_SHARED_INFO_ERROR);
 901                 return 0;
 902                 }
 903         return 1;
 904         }
 905
 906 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri)
 907         {
 908         EVP_PKEY_CTX *pctx;
 909         EVP_PKEY *pkey;
 910         EVP_CIPHER_CTX *ctx;
 911         int keylen;
 912         X509_ALGOR *talg, *wrap_alg = NULL;
 913         ASN1_OBJECT *aoid;
 914         ASN1_BIT_STRING *pubkey;
 915         ASN1_STRING *wrap_str;
 916         ASN1_OCTET_STRING *ukm;
 917         unsigned char *penc = NULL;
 918         int penclen;
 919         int rv = 0;
 920         int ecdh_nid, kdf_type, kdf_nid, wrap_nid;
 921         const EVP_MD *kdf_md;
 922         pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 923         if (!pctx)
 924                 return 0;
 925         /* Get ephemeral key */
 926         pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 927         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 928                                                         NULL, NULL, NULL))
 929                 goto err;
 930         X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 931         /* Is everything uninitialised? */
 932         if (aoid == OBJ_nid2obj(NID_undef))
 933                 {
 934
 935                 EC_KEY *eckey = pkey->pkey.ec;
 936                 /* Set the key */
 937                 unsigned char *p;
 938
 939                 penclen = i2o_ECPublicKey(eckey, NULL);
 940                 if (penclen <= 0)
 941                         goto err;
 942                 penc = OPENSSL_malloc(penclen);
 943                 if (!penc)
 944                         goto err;
 945                 p = penc;
 946                 penclen = i2o_ECPublicKey(eckey, &p);
 947                 if (penclen <= 0)
 948                         goto err;
 949                 ASN1_STRING_set0(pubkey, penc, penclen);
 950                 pubkey->flags&= ~(ASN1_STRING_FLAG_BITS_LEFT|0x07);
 951                 pubkey->flags|=ASN1_STRING_FLAG_BITS_LEFT;
 952
 953                 penc = NULL;
 954                 X509_ALGOR_set0(talg, OBJ_nid2obj(NID_X9_62_id_ecPublicKey),
 955                                                         V_ASN1_UNDEF, NULL);
 956                 }
 957
 958         /* See if custom paraneters set */
 959         kdf_type = EVP_PKEY_CTX_get_ecdh_kdf_type(pctx);
 960         if (kdf_type <= 0)
 961                 goto err;
 962         if (!EVP_PKEY_CTX_get_ecdh_kdf_md(pctx, &kdf_md))
 963                 goto err;
 964         ecdh_nid = EVP_PKEY_CTX_get_ecdh_cofactor_mode(pctx);
 965         if (ecdh_nid < 0)
 966                 goto err;
 967         else if (ecdh_nid == 0)
 968                 ecdh_nid = NID_dh_std_kdf;
 969         else if (ecdh_nid == 1)
 970                 ecdh_nid = NID_dh_cofactor_kdf;
 971
 972         if (kdf_type == EVP_PKEY_ECDH_KDF_NONE)
 973                 {
 974                 kdf_type = EVP_PKEY_ECDH_KDF_X9_62;
 975                 if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0)
 976                         goto err;
 977                 }
 978         else
 979                 /* Uknown KDF */
 980                 goto err;
 981         if (kdf_md == NULL)
 982                 {
 983                 /* Fixme later for better MD */
 984                 kdf_md = EVP_sha1();
 985                 if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
 986                         goto err;
 987                 }
 988
 989         if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 990                 goto err;
 991
 992         /* Lookup NID for KDF+cofactor+digest */
 993
 994         if (!OBJ_find_sigid_by_algs(&kdf_nid, EVP_MD_type(kdf_md), ecdh_nid))
 995                 goto err;
 996         /* Get wrap NID */
 997         ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 998         wrap_nid = EVP_CIPHER_CTX_type(ctx);
 999         keylen = EVP_CIPHER_CTX_key_length(ctx);
1000
1001         /* Package wrap algorithm in an AlgorithmIdentifier */
1002
1003         wrap_alg = X509_ALGOR_new();
1004         if (!wrap_alg)
1005                 goto err;
1006         X509_ALGOR_set0(wrap_alg, OBJ_nid2obj(wrap_nid), V_ASN1_UNDEF, NULL);
1007
1008         if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
1009                 goto err;
1010         if (!ecdh_cms_set_ukm(pctx, wrap_alg, ukm, keylen))
1011                 goto err;
1012
1013         /* Now need to wrap encoding of wrap AlgorithmIdentifier into
1014          * parameter of another AlgorithmIdentifier.
1015          */
1016         penc = NULL;
1017         penclen = i2d_X509_ALGOR(wrap_alg, &penc);
1018         if (!penc || !penclen)
1019                 goto err;
1020         wrap_str = ASN1_STRING_new();
1021         if (!wrap_str)
1022                 goto err;
1023         ASN1_STRING_set0(wrap_str, penc, penclen);
1024         penc = NULL;
1025         X509_ALGOR_set0(talg, OBJ_nid2obj(kdf_nid), V_ASN1_SEQUENCE, wrap_str);
1026
1027         rv = 1;
1028
1029         err:
1030         if (penc)
1031                 OPENSSL_free(penc);
1032         if (wrap_alg)
1033                 X509_ALGOR_free(wrap_alg);
1034         return rv;
1035         }
1036
1037 #endif