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 "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 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri);
  71 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri);
  72
  73 static int eckey_param2type(int *pptype, void **ppval, EC_KEY *ec_key)
  74 {
  75     const EC_GROUP *group;
  76     int nid;
  77     if (ec_key == NULL || (group = EC_KEY_get0_group(ec_key)) == NULL) {
  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     } else {                    /* explicit parameters */
  88
  89         ASN1_STRING *pstr = NULL;
  90         pstr = ASN1_STRING_new();
  91         if (!pstr)
  92             return 0;
  93         pstr->length = i2d_ECParameters(ec_key, &pstr->data);
  94         if (pstr->length <= 0) {
  95             ASN1_STRING_free(pstr);
  96             ECerr(EC_F_ECKEY_PARAM2TYPE, ERR_R_EC_LIB);
  97             return 0;
  98         }
  99         *ppval = pstr;
 100         *pptype = V_ASN1_SEQUENCE;
 101     }
 102     return 1;
 103 }
 104
 105 static int eckey_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 106 {
 107     EC_KEY *ec_key = pkey->pkey.ec;
 108     void *pval = NULL;
 109     int ptype;
 110     unsigned char *penc = NULL, *p;
 111     int penclen;
 112
 113     if (!eckey_param2type(&ptype, &pval, ec_key)) {
 114         ECerr(EC_F_ECKEY_PUB_ENCODE, ERR_R_EC_LIB);
 115         return 0;
 116     }
 117     penclen = i2o_ECPublicKey(ec_key, NULL);
 118     if (penclen <= 0)
 119         goto err;
 120     penc = OPENSSL_malloc(penclen);
 121     if (!penc)
 122         goto err;
 123     p = penc;
 124     penclen = i2o_ECPublicKey(ec_key, &p);
 125     if (penclen <= 0)
 126         goto err;
 127     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(EVP_PKEY_EC),
 128                                ptype, pval, penc, penclen))
 129         return 1;
 130  err:
 131     if (ptype == V_ASN1_OBJECT)
 132         ASN1_OBJECT_free(pval);
 133     else
 134         ASN1_STRING_free(pval);
 135     OPENSSL_free(penc);
 136     return 0;
 137 }
 138
 139 static EC_KEY *eckey_type2param(int ptype, void *pval)
 140 {
 141     EC_KEY *eckey = NULL;
 142     if (ptype == V_ASN1_SEQUENCE) {
 143         ASN1_STRING *pstr = pval;
 144         const unsigned char *pm = NULL;
 145         int pmlen;
 146         pm = pstr->data;
 147         pmlen = pstr->length;
 148         if ((eckey = d2i_ECParameters(NULL, &pm, pmlen)) == NULL) {
 149             ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
 150             goto ecerr;
 151         }
 152     } else if (ptype == V_ASN1_OBJECT) {
 153         ASN1_OBJECT *poid = pval;
 154         EC_GROUP *group;
 155
 156         /*
 157          * type == V_ASN1_OBJECT => the parameters are given by an asn1 OID
 158          */
 159         if ((eckey = EC_KEY_new()) == NULL) {
 160             ECerr(EC_F_ECKEY_TYPE2PARAM, ERR_R_MALLOC_FAILURE);
 161             goto ecerr;
 162         }
 163         group = EC_GROUP_new_by_curve_name(OBJ_obj2nid(poid));
 164         if (group == NULL)
 165             goto ecerr;
 166         EC_GROUP_set_asn1_flag(group, OPENSSL_EC_NAMED_CURVE);
 167         if (EC_KEY_set_group(eckey, group) == 0)
 168             goto ecerr;
 169         EC_GROUP_free(group);
 170     } else {
 171         ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
 172         goto ecerr;
 173     }
 174
 175     return eckey;
 176
 177  ecerr:
 178     EC_KEY_free(eckey);
 179     return NULL;
 180 }
 181
 182 static int eckey_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
 183 {
 184     const unsigned char *p = NULL;
 185     void *pval;
 186     int ptype, pklen;
 187     EC_KEY *eckey = NULL;
 188     X509_ALGOR *palg;
 189
 190     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
 191         return 0;
 192     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 193
 194     eckey = eckey_type2param(ptype, pval);
 195
 196     if (!eckey) {
 197         ECerr(EC_F_ECKEY_PUB_DECODE, ERR_R_EC_LIB);
 198         return 0;
 199     }
 200
 201     /* We have parameters now set public key */
 202     if (!o2i_ECPublicKey(&eckey, &p, pklen)) {
 203         ECerr(EC_F_ECKEY_PUB_DECODE, EC_R_DECODE_ERROR);
 204         goto ecerr;
 205     }
 206
 207     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 208     return 1;
 209
 210  ecerr:
 211     EC_KEY_free(eckey);
 212     return 0;
 213 }
 214
 215 static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 216 {
 217     int r;
 218     const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec);
 219     const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec),
 220         *pb = EC_KEY_get0_public_key(b->pkey.ec);
 221     r = EC_POINT_cmp(group, pa, pb, NULL);
 222     if (r == 0)
 223         return 1;
 224     if (r == 1)
 225         return 0;
 226     return -2;
 227 }
 228
 229 static int eckey_priv_decode(EVP_PKEY *pkey, PKCS8_PRIV_KEY_INFO *p8)
 230 {
 231     const unsigned char *p = NULL;
 232     void *pval;
 233     int ptype, pklen;
 234     EC_KEY *eckey = NULL;
 235     X509_ALGOR *palg;
 236
 237     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 238         return 0;
 239     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 240
 241     eckey = eckey_type2param(ptype, pval);
 242
 243     if (!eckey)
 244         goto ecliberr;
 245
 246     /* We have parameters now set private key */
 247     if (!d2i_ECPrivateKey(&eckey, &p, pklen)) {
 248         ECerr(EC_F_ECKEY_PRIV_DECODE, EC_R_DECODE_ERROR);
 249         goto ecerr;
 250     }
 251
 252     /* calculate public key (if necessary) */
 253     if (EC_KEY_get0_public_key(eckey) == NULL) {
 254         const BIGNUM *priv_key;
 255         const EC_GROUP *group;
 256         EC_POINT *pub_key;
 257         /*
 258          * the public key was not included in the SEC1 private key =>
 259          * calculate the public key
 260          */
 261         group = EC_KEY_get0_group(eckey);
 262         pub_key = EC_POINT_new(group);
 263         if (pub_key == NULL) {
 264             ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 265             goto ecliberr;
 266         }
 267         if (!EC_POINT_copy(pub_key, EC_GROUP_get0_generator(group))) {
 268             EC_POINT_free(pub_key);
 269             ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 270             goto ecliberr;
 271         }
 272         priv_key = EC_KEY_get0_private_key(eckey);
 273         if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, NULL)) {
 274             EC_POINT_free(pub_key);
 275             ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 276             goto ecliberr;
 277         }
 278         if (EC_KEY_set_public_key(eckey, pub_key) == 0) {
 279             EC_POINT_free(pub_key);
 280             ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 281             goto ecliberr;
 282         }
 283         EC_POINT_free(pub_key);
 284     }
 285
 286     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 287     return 1;
 288
 289  ecliberr:
 290     ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 291  ecerr:
 292     EC_KEY_free(eckey);
 293     return 0;
 294 }
 295
 296 static int eckey_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 297 {
 298     EC_KEY *ec_key;
 299     unsigned char *ep, *p;
 300     int eplen, ptype;
 301     void *pval;
 302     unsigned int tmp_flags, old_flags;
 303
 304     ec_key = pkey->pkey.ec;
 305
 306     if (!eckey_param2type(&ptype, &pval, ec_key)) {
 307         ECerr(EC_F_ECKEY_PRIV_ENCODE, EC_R_DECODE_ERROR);
 308         return 0;
 309     }
 310
 311     /* set the private key */
 312
 313     /*
 314      * do not include the parameters in the SEC1 private key see PKCS#11
 315      * 12.11
 316      */
 317     old_flags = EC_KEY_get_enc_flags(ec_key);
 318     tmp_flags = old_flags | EC_PKEY_NO_PARAMETERS;
 319     EC_KEY_set_enc_flags(ec_key, tmp_flags);
 320     eplen = i2d_ECPrivateKey(ec_key, NULL);
 321     if (!eplen) {
 322         EC_KEY_set_enc_flags(ec_key, old_flags);
 323         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
 324         return 0;
 325     }
 326     ep = OPENSSL_malloc(eplen);
 327     if (!ep) {
 328         EC_KEY_set_enc_flags(ec_key, old_flags);
 329         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 330         return 0;
 331     }
 332     p = ep;
 333     if (!i2d_ECPrivateKey(ec_key, &p)) {
 334         EC_KEY_set_enc_flags(ec_key, old_flags);
 335         OPENSSL_free(ep);
 336         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
 337         return 0;
 338     }
 339     /* restore old encoding flags */
 340     EC_KEY_set_enc_flags(ec_key, old_flags);
 341
 342     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0,
 343                          ptype, pval, ep, eplen))
 344         return 0;
 345
 346     return 1;
 347 }
 348
 349 static int int_ec_size(const EVP_PKEY *pkey)
 350 {
 351     return ECDSA_size(pkey->pkey.ec);
 352 }
 353
 354 static int ec_bits(const EVP_PKEY *pkey)
 355 {
 356     BIGNUM *order = BN_new();
 357     const EC_GROUP *group;
 358     int ret;
 359
 360     if (!order) {
 361         ERR_clear_error();
 362         return 0;
 363     }
 364     group = EC_KEY_get0_group(pkey->pkey.ec);
 365     if (!EC_GROUP_get_order(group, order, NULL)) {
 366         ERR_clear_error();
 367         return 0;
 368     }
 369
 370     ret = BN_num_bits(order);
 371     BN_free(order);
 372     return ret;
 373 }
 374
 375 static int ec_security_bits(const EVP_PKEY *pkey)
 376 {
 377     int ecbits = ec_bits(pkey);
 378     if (ecbits >= 512)
 379         return 256;
 380     if (ecbits >= 384)
 381         return 192;
 382     if (ecbits >= 256)
 383         return 128;
 384     if (ecbits >= 224)
 385         return 112;
 386     if (ecbits >= 160)
 387         return 80;
 388     return ecbits / 2;
 389 }
 390
 391 static int ec_missing_parameters(const EVP_PKEY *pkey)
 392 {
 393     if (EC_KEY_get0_group(pkey->pkey.ec) == NULL)
 394         return 1;
 395     return 0;
 396 }
 397
 398 static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 399 {
 400     EC_GROUP *group = EC_GROUP_dup(EC_KEY_get0_group(from->pkey.ec));
 401     if (group == NULL)
 402         return 0;
 403     if (EC_KEY_set_group(to->pkey.ec, group) == 0)
 404         return 0;
 405     EC_GROUP_free(group);
 406     return 1;
 407 }
 408
 409 static int ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 410 {
 411     const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec),
 412         *group_b = EC_KEY_get0_group(b->pkey.ec);
 413     if (EC_GROUP_cmp(group_a, group_b, NULL))
 414         return 0;
 415     else
 416         return 1;
 417 }
 418
 419 static void int_ec_free(EVP_PKEY *pkey)
 420 {
 421     EC_KEY_free(pkey->pkey.ec);
 422 }
 423
 424 static int do_EC_KEY_print(BIO *bp, const EC_KEY *x, int off, int ktype)
 425 {
 426     unsigned char *buffer = NULL;
 427     const char *ecstr;
 428     size_t buf_len = 0, i;
 429     int ret = 0, reason = ERR_R_BIO_LIB;
 430     BIGNUM *pub_key = NULL, *order = NULL;
 431     BN_CTX *ctx = NULL;
 432     const EC_GROUP *group;
 433     const EC_POINT *public_key;
 434     const BIGNUM *priv_key;
 435
 436     if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL) {
 437         reason = ERR_R_PASSED_NULL_PARAMETER;
 438         goto err;
 439     }
 440
 441     ctx = BN_CTX_new();
 442     if (ctx == NULL) {
 443         reason = ERR_R_MALLOC_FAILURE;
 444         goto err;
 445     }
 446
 447     if (ktype > 0) {
 448         public_key = EC_KEY_get0_public_key(x);
 449         if (public_key != NULL) {
 450             if ((pub_key = EC_POINT_point2bn(group, public_key,
 451                                              EC_KEY_get_conv_form(x), NULL,
 452                                              ctx)) == NULL) {
 453                 reason = ERR_R_EC_LIB;
 454                 goto err;
 455             }
 456             buf_len = (size_t)BN_num_bytes(pub_key);
 457         }
 458     }
 459
 460     if (ktype == 2) {
 461         priv_key = EC_KEY_get0_private_key(x);
 462         if (priv_key && (i = (size_t)BN_num_bytes(priv_key)) > buf_len)
 463             buf_len = i;
 464     } else
 465         priv_key = NULL;
 466
 467     if (ktype > 0) {
 468         buf_len += 10;
 469         if ((buffer = OPENSSL_malloc(buf_len)) == NULL) {
 470             reason = ERR_R_MALLOC_FAILURE;
 471             goto err;
 472         }
 473     }
 474     if (ktype == 2)
 475         ecstr = "Private-Key";
 476     else if (ktype == 1)
 477         ecstr = "Public-Key";
 478     else
 479         ecstr = "ECDSA-Parameters";
 480
 481     if (!BIO_indent(bp, off, 128))
 482         goto err;
 483     if ((order = BN_new()) == NULL)
 484         goto err;
 485     if (!EC_GROUP_get_order(group, order, NULL))
 486         goto err;
 487     if (BIO_printf(bp, "%s: (%d bit)\n", ecstr, BN_num_bits(order)) <= 0)
 488         goto err;
 489
 490     if ((priv_key != NULL) && !ASN1_bn_print(bp, "priv:", priv_key,
 491                                              buffer, off))
 492         goto err;
 493     if ((pub_key != NULL) && !ASN1_bn_print(bp, "pub: ", pub_key,
 494                                             buffer, off))
 495         goto err;
 496     if (!ECPKParameters_print(bp, group, off))
 497         goto err;
 498     ret = 1;
 499  err:
 500     if (!ret)
 501         ECerr(EC_F_DO_EC_KEY_PRINT, reason);
 502     BN_free(pub_key);
 503     BN_free(order);
 504     BN_CTX_free(ctx);
 505     OPENSSL_free(buffer);
 506     return (ret);
 507 }
 508
 509 static int eckey_param_decode(EVP_PKEY *pkey,
 510                               const unsigned char **pder, int derlen)
 511 {
 512     EC_KEY *eckey;
 513
 514     if ((eckey = d2i_ECParameters(NULL, pder, derlen)) == NULL) {
 515         ECerr(EC_F_ECKEY_PARAM_DECODE, ERR_R_EC_LIB);
 516         return 0;
 517     }
 518     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 519     return 1;
 520 }
 521
 522 static int eckey_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 523 {
 524     return i2d_ECParameters(pkey->pkey.ec, pder);
 525 }
 526
 527 static int eckey_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 528                              ASN1_PCTX *ctx)
 529 {
 530     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 0);
 531 }
 532
 533 static int eckey_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 534                            ASN1_PCTX *ctx)
 535 {
 536     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 1);
 537 }
 538
 539 static int eckey_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 540                             ASN1_PCTX *ctx)
 541 {
 542     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 2);
 543 }
 544
 545 static int old_ec_priv_decode(EVP_PKEY *pkey,
 546                               const unsigned char **pder, int derlen)
 547 {
 548     EC_KEY *ec;
 549
 550     if ((ec = d2i_ECPrivateKey(NULL, pder, derlen)) == NULL) {
 551         ECerr(EC_F_OLD_EC_PRIV_DECODE, EC_R_DECODE_ERROR);
 552         return 0;
 553     }
 554     EVP_PKEY_assign_EC_KEY(pkey, ec);
 555     return 1;
 556 }
 557
 558 static int old_ec_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
 559 {
 560     return i2d_ECPrivateKey(pkey->pkey.ec, pder);
 561 }
 562
 563 static int ec_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 564 {
 565     switch (op) {
 566     case ASN1_PKEY_CTRL_PKCS7_SIGN:
 567         if (arg1 == 0) {
 568             int snid, hnid;
 569             X509_ALGOR *alg1, *alg2;
 570             PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2);
 571             if (alg1 == NULL || alg1->algorithm == NULL)
 572                 return -1;
 573             hnid = OBJ_obj2nid(alg1->algorithm);
 574             if (hnid == NID_undef)
 575                 return -1;
 576             if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 577                 return -1;
 578             X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 579         }
 580         return 1;
 581 #ifndef OPENSSL_NO_CMS
 582     case ASN1_PKEY_CTRL_CMS_SIGN:
 583         if (arg1 == 0) {
 584             int snid, hnid;
 585             X509_ALGOR *alg1, *alg2;
 586             CMS_SignerInfo_get0_algs(arg2, NULL, NULL, &alg1, &alg2);
 587             if (alg1 == NULL || alg1->algorithm == NULL)
 588                 return -1;
 589             hnid = OBJ_obj2nid(alg1->algorithm);
 590             if (hnid == NID_undef)
 591                 return -1;
 592             if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 593                 return -1;
 594             X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 595         }
 596         return 1;
 597
 598     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 599         if (arg1 == 1)
 600             return ecdh_cms_decrypt(arg2);
 601         else if (arg1 == 0)
 602             return ecdh_cms_encrypt(arg2);
 603         return -2;
 604
 605     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 606         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 607         return 1;
 608 #endif
 609
 610     case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
 611         *(int *)arg2 = NID_sha256;
 612         return 2;
 613
 614     default:
 615         return -2;
 616
 617     }
 618
 619 }
 620
 621 const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = {
 622     EVP_PKEY_EC,
 623     EVP_PKEY_EC,
 624     0,
 625     "EC",
 626     "OpenSSL EC algorithm",
 627
 628     eckey_pub_decode,
 629     eckey_pub_encode,
 630     eckey_pub_cmp,
 631     eckey_pub_print,
 632
 633     eckey_priv_decode,
 634     eckey_priv_encode,
 635     eckey_priv_print,
 636
 637     int_ec_size,
 638     ec_bits,
 639     ec_security_bits,
 640
 641     eckey_param_decode,
 642     eckey_param_encode,
 643     ec_missing_parameters,
 644     ec_copy_parameters,
 645     ec_cmp_parameters,
 646     eckey_param_print,
 647     0,
 648
 649     int_ec_free,
 650     ec_pkey_ctrl,
 651     old_ec_priv_decode,
 652     old_ec_priv_encode
 653 };
 654
 655 #ifndef OPENSSL_NO_CMS
 656
 657 static int ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 658                                 X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 659 {
 660     ASN1_OBJECT *aoid;
 661     int atype;
 662     void *aval;
 663     int rv = 0;
 664     EVP_PKEY *pkpeer = NULL;
 665     EC_KEY *ecpeer = NULL;
 666     const unsigned char *p;
 667     int plen;
 668     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 669     if (OBJ_obj2nid(aoid) != NID_X9_62_id_ecPublicKey)
 670         goto err;
 671     /* If absent parameters get group from main key */
 672     if (atype == V_ASN1_UNDEF || atype == V_ASN1_NULL) {
 673         const EC_GROUP *grp;
 674         EVP_PKEY *pk;
 675         pk = EVP_PKEY_CTX_get0_pkey(pctx);
 676         if (!pk)
 677             goto err;
 678         grp = EC_KEY_get0_group(pk->pkey.ec);
 679         ecpeer = EC_KEY_new();
 680         if (!ecpeer)
 681             goto err;
 682         if (!EC_KEY_set_group(ecpeer, grp))
 683             goto err;
 684     } else {
 685         ecpeer = eckey_type2param(atype, aval);
 686         if (!ecpeer)
 687             goto err;
 688     }
 689     /* We have parameters now set public key */
 690     plen = ASN1_STRING_length(pubkey);
 691     p = ASN1_STRING_data(pubkey);
 692     if (!p || !plen)
 693         goto err;
 694     if (!o2i_ECPublicKey(&ecpeer, &p, plen))
 695         goto err;
 696     pkpeer = EVP_PKEY_new();
 697     if (!pkpeer)
 698         goto err;
 699     EVP_PKEY_set1_EC_KEY(pkpeer, ecpeer);
 700     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 701         rv = 1;
 702  err:
 703     EC_KEY_free(ecpeer);
 704     EVP_PKEY_free(pkpeer);
 705     return rv;
 706 }
 707
 708 /* Set KDF parameters based on KDF NID */
 709 static int ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid)
 710 {
 711     int kdf_nid, kdfmd_nid, cofactor;
 712     const EVP_MD *kdf_md;
 713     if (eckdf_nid == NID_undef)
 714         return 0;
 715
 716     /* Lookup KDF type, cofactor mode and digest */
 717     if (!OBJ_find_sigid_algs(eckdf_nid, &kdfmd_nid, &kdf_nid))
 718         return 0;
 719
 720     if (kdf_nid == NID_dh_std_kdf)
 721         cofactor = 0;
 722     else if (kdf_nid == NID_dh_cofactor_kdf)
 723         cofactor = 1;
 724     else
 725         return 0;
 726
 727     if (EVP_PKEY_CTX_set_ecdh_cofactor_mode(pctx, cofactor) <= 0)
 728         return 0;
 729
 730     if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, EVP_PKEY_ECDH_KDF_X9_62) <= 0)
 731         return 0;
 732
 733     kdf_md = EVP_get_digestbynid(kdfmd_nid);
 734     if (!kdf_md)
 735         return 0;
 736
 737     if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
 738         return 0;
 739     return 1;
 740 }
 741
 742 static int ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 743 {
 744     int rv = 0;
 745
 746     X509_ALGOR *alg, *kekalg = NULL;
 747     ASN1_OCTET_STRING *ukm;
 748     const unsigned char *p;
 749     unsigned char *der = NULL;
 750     int plen, keylen;
 751     const EVP_CIPHER *kekcipher;
 752     EVP_CIPHER_CTX *kekctx;
 753
 754     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 755         return 0;
 756
 757     if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) {
 758         ECerr(EC_F_ECDH_CMS_SET_SHARED_INFO, EC_R_KDF_PARAMETER_ERROR);
 759         return 0;
 760     }
 761
 762     if (alg->parameter->type != V_ASN1_SEQUENCE)
 763         return 0;
 764
 765     p = alg->parameter->value.sequence->data;
 766     plen = alg->parameter->value.sequence->length;
 767     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 768     if (!kekalg)
 769         goto err;
 770     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 771     if (!kekctx)
 772         goto err;
 773     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 774     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 775         goto err;
 776     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 777         goto err;
 778     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 779         goto err;
 780
 781     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 782     if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
 783         goto err;
 784
 785     plen = CMS_SharedInfo_encode(&der, kekalg, ukm, keylen);
 786
 787     if (!plen)
 788         goto err;
 789
 790     if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
 791         goto err;
 792     der = NULL;
 793
 794     rv = 1;
 795  err:
 796     X509_ALGOR_free(kekalg);
 797     OPENSSL_free(der);
 798     return rv;
 799 }
 800
 801 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri)
 802 {
 803     EVP_PKEY_CTX *pctx;
 804     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 805     if (!pctx)
 806         return 0;
 807     /* See if we need to set peer key */
 808     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 809         X509_ALGOR *alg;
 810         ASN1_BIT_STRING *pubkey;
 811         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 812                                                  NULL, NULL, NULL))
 813             return 0;
 814         if (!alg || !pubkey)
 815             return 0;
 816         if (!ecdh_cms_set_peerkey(pctx, alg, pubkey)) {
 817             ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_PEER_KEY_ERROR);
 818             return 0;
 819         }
 820     }
 821     /* Set ECDH derivation parameters and initialise unwrap context */
 822     if (!ecdh_cms_set_shared_info(pctx, ri)) {
 823         ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_SHARED_INFO_ERROR);
 824         return 0;
 825     }
 826     return 1;
 827 }
 828
 829 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri)
 830 {
 831     EVP_PKEY_CTX *pctx;
 832     EVP_PKEY *pkey;
 833     EVP_CIPHER_CTX *ctx;
 834     int keylen;
 835     X509_ALGOR *talg, *wrap_alg = NULL;
 836     ASN1_OBJECT *aoid;
 837     ASN1_BIT_STRING *pubkey;
 838     ASN1_STRING *wrap_str;
 839     ASN1_OCTET_STRING *ukm;
 840     unsigned char *penc = NULL;
 841     int penclen;
 842     int rv = 0;
 843     int ecdh_nid, kdf_type, kdf_nid, wrap_nid;
 844     const EVP_MD *kdf_md;
 845     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 846     if (!pctx)
 847         return 0;
 848     /* Get ephemeral key */
 849     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 850     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 851                                              NULL, NULL, NULL))
 852         goto err;
 853     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 854     /* Is everything uninitialised? */
 855     if (aoid == OBJ_nid2obj(NID_undef)) {
 856
 857         EC_KEY *eckey = pkey->pkey.ec;
 858         /* Set the key */
 859         unsigned char *p;
 860
 861         penclen = i2o_ECPublicKey(eckey, NULL);
 862         if (penclen <= 0)
 863             goto err;
 864         penc = OPENSSL_malloc(penclen);
 865         if (!penc)
 866             goto err;
 867         p = penc;
 868         penclen = i2o_ECPublicKey(eckey, &p);
 869         if (penclen <= 0)
 870             goto err;
 871         ASN1_STRING_set0(pubkey, penc, penclen);
 872         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 873         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 874
 875         penc = NULL;
 876         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_X9_62_id_ecPublicKey),
 877                         V_ASN1_UNDEF, NULL);
 878     }
 879
 880     /* See if custom paraneters set */
 881     kdf_type = EVP_PKEY_CTX_get_ecdh_kdf_type(pctx);
 882     if (kdf_type <= 0)
 883         goto err;
 884     if (!EVP_PKEY_CTX_get_ecdh_kdf_md(pctx, &kdf_md))
 885         goto err;
 886     ecdh_nid = EVP_PKEY_CTX_get_ecdh_cofactor_mode(pctx);
 887     if (ecdh_nid < 0)
 888         goto err;
 889     else if (ecdh_nid == 0)
 890         ecdh_nid = NID_dh_std_kdf;
 891     else if (ecdh_nid == 1)
 892         ecdh_nid = NID_dh_cofactor_kdf;
 893
 894     if (kdf_type == EVP_PKEY_ECDH_KDF_NONE) {
 895         kdf_type = EVP_PKEY_ECDH_KDF_X9_62;
 896         if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0)
 897             goto err;
 898     } else
 899         /* Uknown KDF */
 900         goto err;
 901     if (kdf_md == NULL) {
 902         /* Fixme later for better MD */
 903         kdf_md = EVP_sha1();
 904         if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
 905             goto err;
 906     }
 907
 908     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 909         goto err;
 910
 911     /* Lookup NID for KDF+cofactor+digest */
 912
 913     if (!OBJ_find_sigid_by_algs(&kdf_nid, EVP_MD_type(kdf_md), ecdh_nid))
 914         goto err;
 915     /* Get wrap NID */
 916     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 917     wrap_nid = EVP_CIPHER_CTX_type(ctx);
 918     keylen = EVP_CIPHER_CTX_key_length(ctx);
 919
 920     /* Package wrap algorithm in an AlgorithmIdentifier */
 921
 922     wrap_alg = X509_ALGOR_new();
 923     if (!wrap_alg)
 924         goto err;
 925     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 926     wrap_alg->parameter = ASN1_TYPE_new();
 927     if (!wrap_alg->parameter)
 928         goto err;
 929     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 930         goto err;
 931     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
 932         ASN1_TYPE_free(wrap_alg->parameter);
 933         wrap_alg->parameter = NULL;
 934     }
 935
 936     if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
 937         goto err;
 938
 939     penclen = CMS_SharedInfo_encode(&penc, wrap_alg, ukm, keylen);
 940
 941     if (!penclen)
 942         goto err;
 943
 944     if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, penc, penclen) <= 0)
 945         goto err;
 946     penc = NULL;
 947
 948     /*
 949      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
 950      * of another AlgorithmIdentifier.
 951      */
 952     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 953     if (!penc || !penclen)
 954         goto err;
 955     wrap_str = ASN1_STRING_new();
 956     if (!wrap_str)
 957         goto err;
 958     ASN1_STRING_set0(wrap_str, penc, penclen);
 959     penc = NULL;
 960     X509_ALGOR_set0(talg, OBJ_nid2obj(kdf_nid), V_ASN1_SEQUENCE, wrap_str);
 961
 962     rv = 1;
 963
 964  err:
 965     OPENSSL_free(penc);
 966     X509_ALGOR_free(wrap_alg);
 967     return rv;
 968 }
 969
 970 #endif