crypto/ec/ec_ameth.c

   1 /*
   2  * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
   3  * 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 #include "internal/cryptlib.h"
  61 #include <openssl/x509.h>
  62 #include <openssl/ec.h>
  63 #include <openssl/bn.h>
  64 #ifndef OPENSSL_NO_CMS
  65 # include <openssl/cms.h>
  66 #endif
  67 #include <openssl/asn1t.h>
  68 #include "internal/asn1_int.h"
  69
  70 #ifndef OPENSSL_NO_CMS
  71 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri);
  72 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri);
  73 #endif
  74
  75 static int eckey_param2type(int *pptype, void **ppval, EC_KEY *ec_key)
  76 {
  77     const EC_GROUP *group;
  78     int nid;
  79     if (ec_key == NULL || (group = EC_KEY_get0_group(ec_key)) == NULL) {
  80         ECerr(EC_F_ECKEY_PARAM2TYPE, EC_R_MISSING_PARAMETERS);
  81         return 0;
  82     }
  83     if (EC_GROUP_get_asn1_flag(group)
  84         && (nid = EC_GROUP_get_curve_name(group)))
  85         /* we have a 'named curve' => just set the OID */
  86     {
  87         *ppval = OBJ_nid2obj(nid);
  88         *pptype = V_ASN1_OBJECT;
  89     } else {                    /* explicit parameters */
  90
  91         ASN1_STRING *pstr = NULL;
  92         pstr = ASN1_STRING_new();
  93         if (pstr == NULL)
  94             return 0;
  95         pstr->length = i2d_ECParameters(ec_key, &pstr->data);
  96         if (pstr->length <= 0) {
  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         ECerr(EC_F_ECKEY_PUB_ENCODE, ERR_R_EC_LIB);
 117         return 0;
 118     }
 119     penclen = i2o_ECPublicKey(ec_key, NULL);
 120     if (penclen <= 0)
 121         goto err;
 122     penc = OPENSSL_malloc(penclen);
 123     if (penc == NULL)
 124         goto err;
 125     p = penc;
 126     penclen = i2o_ECPublicKey(ec_key, &p);
 127     if (penclen <= 0)
 128         goto err;
 129     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(EVP_PKEY_EC),
 130                                ptype, pval, penc, penclen))
 131         return 1;
 132  err:
 133     if (ptype == V_ASN1_OBJECT)
 134         ASN1_OBJECT_free(pval);
 135     else
 136         ASN1_STRING_free(pval);
 137     OPENSSL_free(penc);
 138     return 0;
 139 }
 140
 141 static EC_KEY *eckey_type2param(int ptype, void *pval)
 142 {
 143     EC_KEY *eckey = NULL;
 144     if (ptype == V_ASN1_SEQUENCE) {
 145         ASN1_STRING *pstr = pval;
 146         const unsigned char *pm = NULL;
 147         int pmlen;
 148         pm = pstr->data;
 149         pmlen = pstr->length;
 150         if ((eckey = d2i_ECParameters(NULL, &pm, pmlen)) == NULL) {
 151             ECerr(EC_F_ECKEY_TYPE2PARAM, 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 asn1 OID
 160          */
 161         if ((eckey = EC_KEY_new()) == NULL) {
 162             ECerr(EC_F_ECKEY_TYPE2PARAM, ERR_R_MALLOC_FAILURE);
 163             goto ecerr;
 164         }
 165         group = EC_GROUP_new_by_curve_name(OBJ_obj2nid(poid));
 166         if (group == NULL)
 167             goto ecerr;
 168         EC_GROUP_set_asn1_flag(group, OPENSSL_EC_NAMED_CURVE);
 169         if (EC_KEY_set_group(eckey, group) == 0)
 170             goto ecerr;
 171         EC_GROUP_free(group);
 172     } else {
 173         ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
 174         goto ecerr;
 175     }
 176
 177     return eckey;
 178
 179  ecerr:
 180     EC_KEY_free(eckey);
 181     return NULL;
 182 }
 183
 184 static int eckey_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
 185 {
 186     const unsigned char *p = NULL;
 187     void *pval;
 188     int ptype, pklen;
 189     EC_KEY *eckey = NULL;
 190     X509_ALGOR *palg;
 191
 192     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
 193         return 0;
 194     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 195
 196     eckey = eckey_type2param(ptype, pval);
 197
 198     if (!eckey) {
 199         ECerr(EC_F_ECKEY_PUB_DECODE, ERR_R_EC_LIB);
 200         return 0;
 201     }
 202
 203     /* We have parameters now set public key */
 204     if (!o2i_ECPublicKey(&eckey, &p, pklen)) {
 205         ECerr(EC_F_ECKEY_PUB_DECODE, EC_R_DECODE_ERROR);
 206         goto ecerr;
 207     }
 208
 209     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 210     return 1;
 211
 212  ecerr:
 213     EC_KEY_free(eckey);
 214     return 0;
 215 }
 216
 217 static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 218 {
 219     int r;
 220     const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec);
 221     const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec),
 222         *pb = EC_KEY_get0_public_key(b->pkey.ec);
 223     r = EC_POINT_cmp(group, pa, pb, NULL);
 224     if (r == 0)
 225         return 1;
 226     if (r == 1)
 227         return 0;
 228     return -2;
 229 }
 230
 231 static int eckey_priv_decode(EVP_PKEY *pkey, PKCS8_PRIV_KEY_INFO *p8)
 232 {
 233     const unsigned char *p = NULL;
 234     void *pval;
 235     int ptype, pklen;
 236     EC_KEY *eckey = NULL;
 237     X509_ALGOR *palg;
 238
 239     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 240         return 0;
 241     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 242
 243     eckey = eckey_type2param(ptype, pval);
 244
 245     if (!eckey)
 246         goto ecliberr;
 247
 248     /* We have parameters now set private key */
 249     if (!d2i_ECPrivateKey(&eckey, &p, pklen)) {
 250         ECerr(EC_F_ECKEY_PRIV_DECODE, EC_R_DECODE_ERROR);
 251         goto ecerr;
 252     }
 253
 254     /* calculate public key (if necessary) */
 255     if (EC_KEY_get0_public_key(eckey) == NULL) {
 256         const BIGNUM *priv_key;
 257         const EC_GROUP *group;
 258         EC_POINT *pub_key;
 259         /*
 260          * the public key was not included in the SEC1 private key =>
 261          * calculate the public key
 262          */
 263         group = EC_KEY_get0_group(eckey);
 264         pub_key = EC_POINT_new(group);
 265         if (pub_key == NULL) {
 266             ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 267             goto ecliberr;
 268         }
 269         if (!EC_POINT_copy(pub_key, EC_GROUP_get0_generator(group))) {
 270             EC_POINT_free(pub_key);
 271             ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 272             goto ecliberr;
 273         }
 274         priv_key = EC_KEY_get0_private_key(eckey);
 275         if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, NULL)) {
 276             EC_POINT_free(pub_key);
 277             ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 278             goto ecliberr;
 279         }
 280         if (EC_KEY_set_public_key(eckey, pub_key) == 0) {
 281             EC_POINT_free(pub_key);
 282             ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 283             goto ecliberr;
 284         }
 285         EC_POINT_free(pub_key);
 286     }
 287
 288     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 289     return 1;
 290
 291  ecliberr:
 292     ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 293  ecerr:
 294     EC_KEY_free(eckey);
 295     return 0;
 296 }
 297
 298 static int eckey_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 299 {
 300     EC_KEY *ec_key;
 301     unsigned char *ep, *p;
 302     int eplen, ptype;
 303     void *pval;
 304     unsigned int tmp_flags, old_flags;
 305
 306     ec_key = pkey->pkey.ec;
 307
 308     if (!eckey_param2type(&ptype, &pval, ec_key)) {
 309         ECerr(EC_F_ECKEY_PRIV_ENCODE, EC_R_DECODE_ERROR);
 310         return 0;
 311     }
 312
 313     /* set the private key */
 314
 315     /*
 316      * do not include the parameters in the SEC1 private key see PKCS#11
 317      * 12.11
 318      */
 319     old_flags = EC_KEY_get_enc_flags(ec_key);
 320     tmp_flags = old_flags | EC_PKEY_NO_PARAMETERS;
 321     EC_KEY_set_enc_flags(ec_key, tmp_flags);
 322     eplen = i2d_ECPrivateKey(ec_key, NULL);
 323     if (!eplen) {
 324         EC_KEY_set_enc_flags(ec_key, old_flags);
 325         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
 326         return 0;
 327     }
 328     ep = OPENSSL_malloc(eplen);
 329     if (ep == NULL) {
 330         EC_KEY_set_enc_flags(ec_key, old_flags);
 331         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 332         return 0;
 333     }
 334     p = ep;
 335     if (!i2d_ECPrivateKey(ec_key, &p)) {
 336         EC_KEY_set_enc_flags(ec_key, old_flags);
 337         OPENSSL_free(ep);
 338         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
 339         return 0;
 340     }
 341     /* restore old encoding flags */
 342     EC_KEY_set_enc_flags(ec_key, old_flags);
 343
 344     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0,
 345                          ptype, pval, ep, eplen))
 346         return 0;
 347
 348     return 1;
 349 }
 350
 351 static int int_ec_size(const EVP_PKEY *pkey)
 352 {
 353     return ECDSA_size(pkey->pkey.ec);
 354 }
 355
 356 static int ec_bits(const EVP_PKEY *pkey)
 357 {
 358     BIGNUM *order = BN_new();
 359     const EC_GROUP *group;
 360     int ret;
 361
 362     if (order == NULL) {
 363         ERR_clear_error();
 364         return 0;
 365     }
 366     group = EC_KEY_get0_group(pkey->pkey.ec);
 367     if (!EC_GROUP_get_order(group, order, NULL)) {
 368         ERR_clear_error();
 369         return 0;
 370     }
 371
 372     ret = BN_num_bits(order);
 373     BN_free(order);
 374     return ret;
 375 }
 376
 377 static int ec_security_bits(const EVP_PKEY *pkey)
 378 {
 379     int ecbits = ec_bits(pkey);
 380     if (ecbits >= 512)
 381         return 256;
 382     if (ecbits >= 384)
 383         return 192;
 384     if (ecbits >= 256)
 385         return 128;
 386     if (ecbits >= 224)
 387         return 112;
 388     if (ecbits >= 160)
 389         return 80;
 390     return ecbits / 2;
 391 }
 392
 393 static int ec_missing_parameters(const EVP_PKEY *pkey)
 394 {
 395     if (EC_KEY_get0_group(pkey->pkey.ec) == NULL)
 396         return 1;
 397     return 0;
 398 }
 399
 400 static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 401 {
 402     EC_GROUP *group = EC_GROUP_dup(EC_KEY_get0_group(from->pkey.ec));
 403     if (group == NULL)
 404         return 0;
 405     if (EC_KEY_set_group(to->pkey.ec, group) == 0)
 406         return 0;
 407     EC_GROUP_free(group);
 408     return 1;
 409 }
 410
 411 static int ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 412 {
 413     const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec),
 414         *group_b = EC_KEY_get0_group(b->pkey.ec);
 415     if (EC_GROUP_cmp(group_a, group_b, NULL))
 416         return 0;
 417     else
 418         return 1;
 419 }
 420
 421 static void int_ec_free(EVP_PKEY *pkey)
 422 {
 423     EC_KEY_free(pkey->pkey.ec);
 424 }
 425
 426 static int do_EC_KEY_print(BIO *bp, const EC_KEY *x, int off, int ktype)
 427 {
 428     unsigned char *buffer = NULL;
 429     const char *ecstr;
 430     size_t buf_len = 0, i;
 431     int ret = 0, reason = ERR_R_BIO_LIB;
 432     BIGNUM *pub_key = NULL, *order = NULL;
 433     BN_CTX *ctx = NULL;
 434     const EC_GROUP *group;
 435     const EC_POINT *public_key;
 436     const BIGNUM *priv_key;
 437
 438     if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL) {
 439         reason = ERR_R_PASSED_NULL_PARAMETER;
 440         goto err;
 441     }
 442
 443     ctx = BN_CTX_new();
 444     if (ctx == NULL) {
 445         reason = ERR_R_MALLOC_FAILURE;
 446         goto err;
 447     }
 448
 449     if (ktype > 0) {
 450         public_key = EC_KEY_get0_public_key(x);
 451         if (public_key != NULL) {
 452             if ((pub_key = EC_POINT_point2bn(group, public_key,
 453                                              EC_KEY_get_conv_form(x), NULL,
 454                                              ctx)) == NULL) {
 455                 reason = ERR_R_EC_LIB;
 456                 goto err;
 457             }
 458             buf_len = (size_t)BN_num_bytes(pub_key);
 459         }
 460     }
 461
 462     if (ktype == 2) {
 463         priv_key = EC_KEY_get0_private_key(x);
 464         if (priv_key && (i = (size_t)BN_num_bytes(priv_key)) > buf_len)
 465             buf_len = i;
 466     } else
 467         priv_key = NULL;
 468
 469     if (ktype > 0) {
 470         buf_len += 10;
 471         if ((buffer = OPENSSL_malloc(buf_len)) == NULL) {
 472             reason = ERR_R_MALLOC_FAILURE;
 473             goto err;
 474         }
 475     }
 476     if (ktype == 2)
 477         ecstr = "Private-Key";
 478     else if (ktype == 1)
 479         ecstr = "Public-Key";
 480     else
 481         ecstr = "ECDSA-Parameters";
 482
 483     if (!BIO_indent(bp, off, 128))
 484         goto err;
 485     if ((order = BN_new()) == NULL)
 486         goto err;
 487     if (!EC_GROUP_get_order(group, order, NULL))
 488         goto err;
 489     if (BIO_printf(bp, "%s: (%d bit)\n", ecstr, BN_num_bits(order)) <= 0)
 490         goto err;
 491
 492     if ((priv_key != NULL) && !ASN1_bn_print(bp, "priv:", priv_key,
 493                                              buffer, off))
 494         goto err;
 495     if ((pub_key != NULL) && !ASN1_bn_print(bp, "pub: ", pub_key,
 496                                             buffer, off))
 497         goto err;
 498     if (!ECPKParameters_print(bp, group, off))
 499         goto err;
 500     ret = 1;
 501  err:
 502     if (!ret)
 503         ECerr(EC_F_DO_EC_KEY_PRINT, reason);
 504     BN_free(pub_key);
 505     BN_free(order);
 506     BN_CTX_free(ctx);
 507     OPENSSL_free(buffer);
 508     return (ret);
 509 }
 510
 511 static int eckey_param_decode(EVP_PKEY *pkey,
 512                               const unsigned char **pder, int derlen)
 513 {
 514     EC_KEY *eckey;
 515
 516     if ((eckey = d2i_ECParameters(NULL, pder, derlen)) == NULL) {
 517         ECerr(EC_F_ECKEY_PARAM_DECODE, ERR_R_EC_LIB);
 518         return 0;
 519     }
 520     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 521     return 1;
 522 }
 523
 524 static int eckey_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 525 {
 526     return i2d_ECParameters(pkey->pkey.ec, pder);
 527 }
 528
 529 static int eckey_param_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, 0);
 533 }
 534
 535 static int eckey_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 536                            ASN1_PCTX *ctx)
 537 {
 538     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 1);
 539 }
 540
 541 static int eckey_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 542                             ASN1_PCTX *ctx)
 543 {
 544     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 2);
 545 }
 546
 547 static int old_ec_priv_decode(EVP_PKEY *pkey,
 548                               const unsigned char **pder, int derlen)
 549 {
 550     EC_KEY *ec;
 551
 552     if ((ec = d2i_ECPrivateKey(NULL, pder, derlen)) == NULL) {
 553         ECerr(EC_F_OLD_EC_PRIV_DECODE, EC_R_DECODE_ERROR);
 554         return 0;
 555     }
 556     EVP_PKEY_assign_EC_KEY(pkey, ec);
 557     return 1;
 558 }
 559
 560 static int old_ec_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
 561 {
 562     return i2d_ECPrivateKey(pkey->pkey.ec, pder);
 563 }
 564
 565 static int ec_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 566 {
 567     switch (op) {
 568     case ASN1_PKEY_CTRL_PKCS7_SIGN:
 569         if (arg1 == 0) {
 570             int snid, hnid;
 571             X509_ALGOR *alg1, *alg2;
 572             PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2);
 573             if (alg1 == NULL || alg1->algorithm == NULL)
 574                 return -1;
 575             hnid = OBJ_obj2nid(alg1->algorithm);
 576             if (hnid == NID_undef)
 577                 return -1;
 578             if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 579                 return -1;
 580             X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 581         }
 582         return 1;
 583 #ifndef OPENSSL_NO_CMS
 584     case ASN1_PKEY_CTRL_CMS_SIGN:
 585         if (arg1 == 0) {
 586             int snid, hnid;
 587             X509_ALGOR *alg1, *alg2;
 588             CMS_SignerInfo_get0_algs(arg2, NULL, NULL, &alg1, &alg2);
 589             if (alg1 == NULL || alg1->algorithm == NULL)
 590                 return -1;
 591             hnid = OBJ_obj2nid(alg1->algorithm);
 592             if (hnid == NID_undef)
 593                 return -1;
 594             if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 595                 return -1;
 596             X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 597         }
 598         return 1;
 599
 600     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 601         if (arg1 == 1)
 602             return ecdh_cms_decrypt(arg2);
 603         else if (arg1 == 0)
 604             return ecdh_cms_encrypt(arg2);
 605         return -2;
 606
 607     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 608         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 609         return 1;
 610 #endif
 611
 612     case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
 613         *(int *)arg2 = NID_sha256;
 614         return 2;
 615
 616     default:
 617         return -2;
 618
 619     }
 620
 621 }
 622
 623 const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = {
 624     EVP_PKEY_EC,
 625     EVP_PKEY_EC,
 626     0,
 627     "EC",
 628     "OpenSSL EC algorithm",
 629
 630     eckey_pub_decode,
 631     eckey_pub_encode,
 632     eckey_pub_cmp,
 633     eckey_pub_print,
 634
 635     eckey_priv_decode,
 636     eckey_priv_encode,
 637     eckey_priv_print,
 638
 639     int_ec_size,
 640     ec_bits,
 641     ec_security_bits,
 642
 643     eckey_param_decode,
 644     eckey_param_encode,
 645     ec_missing_parameters,
 646     ec_copy_parameters,
 647     ec_cmp_parameters,
 648     eckey_param_print,
 649     0,
 650
 651     int_ec_free,
 652     ec_pkey_ctrl,
 653     old_ec_priv_decode,
 654     old_ec_priv_encode
 655 };
 656
 657 #ifndef OPENSSL_NO_CMS
 658
 659 static int ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 660                                 X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 661 {
 662     ASN1_OBJECT *aoid;
 663     int atype;
 664     void *aval;
 665     int rv = 0;
 666     EVP_PKEY *pkpeer = NULL;
 667     EC_KEY *ecpeer = NULL;
 668     const unsigned char *p;
 669     int plen;
 670     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 671     if (OBJ_obj2nid(aoid) != NID_X9_62_id_ecPublicKey)
 672         goto err;
 673     /* If absent parameters get group from main key */
 674     if (atype == V_ASN1_UNDEF || atype == V_ASN1_NULL) {
 675         const EC_GROUP *grp;
 676         EVP_PKEY *pk;
 677         pk = EVP_PKEY_CTX_get0_pkey(pctx);
 678         if (!pk)
 679             goto err;
 680         grp = EC_KEY_get0_group(pk->pkey.ec);
 681         ecpeer = EC_KEY_new();
 682         if (ecpeer == NULL)
 683             goto err;
 684         if (!EC_KEY_set_group(ecpeer, grp))
 685             goto err;
 686     } else {
 687         ecpeer = eckey_type2param(atype, aval);
 688         if (!ecpeer)
 689             goto err;
 690     }
 691     /* We have parameters now set public key */
 692     plen = ASN1_STRING_length(pubkey);
 693     p = ASN1_STRING_data(pubkey);
 694     if (!p || !plen)
 695         goto err;
 696     if (!o2i_ECPublicKey(&ecpeer, &p, plen))
 697         goto err;
 698     pkpeer = EVP_PKEY_new();
 699     if (pkpeer == NULL)
 700         goto err;
 701     EVP_PKEY_set1_EC_KEY(pkpeer, ecpeer);
 702     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 703         rv = 1;
 704  err:
 705     EC_KEY_free(ecpeer);
 706     EVP_PKEY_free(pkpeer);
 707     return rv;
 708 }
 709
 710 /* Set KDF parameters based on KDF NID */
 711 static int ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid)
 712 {
 713     int kdf_nid, kdfmd_nid, cofactor;
 714     const EVP_MD *kdf_md;
 715     if (eckdf_nid == NID_undef)
 716         return 0;
 717
 718     /* Lookup KDF type, cofactor mode and digest */
 719     if (!OBJ_find_sigid_algs(eckdf_nid, &kdfmd_nid, &kdf_nid))
 720         return 0;
 721
 722     if (kdf_nid == NID_dh_std_kdf)
 723         cofactor = 0;
 724     else if (kdf_nid == NID_dh_cofactor_kdf)
 725         cofactor = 1;
 726     else
 727         return 0;
 728
 729     if (EVP_PKEY_CTX_set_ecdh_cofactor_mode(pctx, cofactor) <= 0)
 730         return 0;
 731
 732     if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, EVP_PKEY_ECDH_KDF_X9_62) <= 0)
 733         return 0;
 734
 735     kdf_md = EVP_get_digestbynid(kdfmd_nid);
 736     if (!kdf_md)
 737         return 0;
 738
 739     if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
 740         return 0;
 741     return 1;
 742 }
 743
 744 static int ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 745 {
 746     int rv = 0;
 747
 748     X509_ALGOR *alg, *kekalg = NULL;
 749     ASN1_OCTET_STRING *ukm;
 750     const unsigned char *p;
 751     unsigned char *der = NULL;
 752     int plen, keylen;
 753     const EVP_CIPHER *kekcipher;
 754     EVP_CIPHER_CTX *kekctx;
 755
 756     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 757         return 0;
 758
 759     if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) {
 760         ECerr(EC_F_ECDH_CMS_SET_SHARED_INFO, EC_R_KDF_PARAMETER_ERROR);
 761         return 0;
 762     }
 763
 764     if (alg->parameter->type != V_ASN1_SEQUENCE)
 765         return 0;
 766
 767     p = alg->parameter->value.sequence->data;
 768     plen = alg->parameter->value.sequence->length;
 769     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 770     if (!kekalg)
 771         goto err;
 772     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 773     if (!kekctx)
 774         goto err;
 775     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 776     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 777         goto err;
 778     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 779         goto err;
 780     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 781         goto err;
 782
 783     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 784     if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
 785         goto err;
 786
 787     plen = CMS_SharedInfo_encode(&der, kekalg, ukm, keylen);
 788
 789     if (!plen)
 790         goto err;
 791
 792     if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
 793         goto err;
 794     der = NULL;
 795
 796     rv = 1;
 797  err:
 798     X509_ALGOR_free(kekalg);
 799     OPENSSL_free(der);
 800     return rv;
 801 }
 802
 803 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri)
 804 {
 805     EVP_PKEY_CTX *pctx;
 806     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 807     if (!pctx)
 808         return 0;
 809     /* See if we need to set peer key */
 810     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 811         X509_ALGOR *alg;
 812         ASN1_BIT_STRING *pubkey;
 813         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 814                                                  NULL, NULL, NULL))
 815             return 0;
 816         if (!alg || !pubkey)
 817             return 0;
 818         if (!ecdh_cms_set_peerkey(pctx, alg, pubkey)) {
 819             ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_PEER_KEY_ERROR);
 820             return 0;
 821         }
 822     }
 823     /* Set ECDH derivation parameters and initialise unwrap context */
 824     if (!ecdh_cms_set_shared_info(pctx, ri)) {
 825         ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_SHARED_INFO_ERROR);
 826         return 0;
 827     }
 828     return 1;
 829 }
 830
 831 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri)
 832 {
 833     EVP_PKEY_CTX *pctx;
 834     EVP_PKEY *pkey;
 835     EVP_CIPHER_CTX *ctx;
 836     int keylen;
 837     X509_ALGOR *talg, *wrap_alg = NULL;
 838     ASN1_OBJECT *aoid;
 839     ASN1_BIT_STRING *pubkey;
 840     ASN1_STRING *wrap_str;
 841     ASN1_OCTET_STRING *ukm;
 842     unsigned char *penc = NULL;
 843     int penclen;
 844     int rv = 0;
 845     int ecdh_nid, kdf_type, kdf_nid, wrap_nid;
 846     const EVP_MD *kdf_md;
 847     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 848     if (!pctx)
 849         return 0;
 850     /* Get ephemeral key */
 851     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 852     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 853                                              NULL, NULL, NULL))
 854         goto err;
 855     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 856     /* Is everything uninitialised? */
 857     if (aoid == OBJ_nid2obj(NID_undef)) {
 858
 859         EC_KEY *eckey = pkey->pkey.ec;
 860         /* Set the key */
 861         unsigned char *p;
 862
 863         penclen = i2o_ECPublicKey(eckey, NULL);
 864         if (penclen <= 0)
 865             goto err;
 866         penc = OPENSSL_malloc(penclen);
 867         if (penc == NULL)
 868             goto err;
 869         p = penc;
 870         penclen = i2o_ECPublicKey(eckey, &p);
 871         if (penclen <= 0)
 872             goto err;
 873         ASN1_STRING_set0(pubkey, penc, penclen);
 874         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 875         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 876
 877         penc = NULL;
 878         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_X9_62_id_ecPublicKey),
 879                         V_ASN1_UNDEF, NULL);
 880     }
 881
 882     /* See if custom paraneters set */
 883     kdf_type = EVP_PKEY_CTX_get_ecdh_kdf_type(pctx);
 884     if (kdf_type <= 0)
 885         goto err;
 886     if (!EVP_PKEY_CTX_get_ecdh_kdf_md(pctx, &kdf_md))
 887         goto err;
 888     ecdh_nid = EVP_PKEY_CTX_get_ecdh_cofactor_mode(pctx);
 889     if (ecdh_nid < 0)
 890         goto err;
 891     else if (ecdh_nid == 0)
 892         ecdh_nid = NID_dh_std_kdf;
 893     else if (ecdh_nid == 1)
 894         ecdh_nid = NID_dh_cofactor_kdf;
 895
 896     if (kdf_type == EVP_PKEY_ECDH_KDF_NONE) {
 897         kdf_type = EVP_PKEY_ECDH_KDF_X9_62;
 898         if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0)
 899             goto err;
 900     } else
 901         /* Uknown KDF */
 902         goto err;
 903     if (kdf_md == NULL) {
 904         /* Fixme later for better MD */
 905         kdf_md = EVP_sha1();
 906         if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
 907             goto err;
 908     }
 909
 910     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 911         goto err;
 912
 913     /* Lookup NID for KDF+cofactor+digest */
 914
 915     if (!OBJ_find_sigid_by_algs(&kdf_nid, EVP_MD_type(kdf_md), ecdh_nid))
 916         goto err;
 917     /* Get wrap NID */
 918     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 919     wrap_nid = EVP_CIPHER_CTX_type(ctx);
 920     keylen = EVP_CIPHER_CTX_key_length(ctx);
 921
 922     /* Package wrap algorithm in an AlgorithmIdentifier */
 923
 924     wrap_alg = X509_ALGOR_new();
 925     if (wrap_alg == NULL)
 926         goto err;
 927     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 928     wrap_alg->parameter = ASN1_TYPE_new();
 929     if (wrap_alg->parameter == NULL)
 930         goto err;
 931     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 932         goto err;
 933     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
 934         ASN1_TYPE_free(wrap_alg->parameter);
 935         wrap_alg->parameter = NULL;
 936     }
 937
 938     if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
 939         goto err;
 940
 941     penclen = CMS_SharedInfo_encode(&penc, wrap_alg, ukm, keylen);
 942
 943     if (!penclen)
 944         goto err;
 945
 946     if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, penc, penclen) <= 0)
 947         goto err;
 948     penc = NULL;
 949
 950     /*
 951      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
 952      * of another AlgorithmIdentifier.
 953      */
 954     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 955     if (!penc || !penclen)
 956         goto err;
 957     wrap_str = ASN1_STRING_new();
 958     if (wrap_str == NULL)
 959         goto err;
 960     ASN1_STRING_set0(wrap_str, penc, penclen);
 961     penc = NULL;
 962     X509_ALGOR_set0(talg, OBJ_nid2obj(kdf_nid), V_ASN1_SEQUENCE, wrap_str);
 963
 964     rv = 1;
 965
 966  err:
 967     OPENSSL_free(penc);
 968     X509_ALGOR_free(wrap_alg);
 969     return rv;
 970 }
 971
 972 #endif