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 "asn1_locl.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     if (penc)
 136         OPENSSL_free(penc);
 137     return 0;
 138 }
 139
 140 static EC_KEY *eckey_type2param(int ptype, void *pval)
 141 {
 142     EC_KEY *eckey = NULL;
 143     if (ptype == V_ASN1_SEQUENCE) {
 144         ASN1_STRING *pstr = pval;
 145         const unsigned char *pm = NULL;
 146         int pmlen;
 147         pm = pstr->data;
 148         pmlen = pstr->length;
 149         if (!(eckey = d2i_ECParameters(NULL, &pm, pmlen))) {
 150             ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
 151             goto ecerr;
 152         }
 153     } else if (ptype == V_ASN1_OBJECT) {
 154         ASN1_OBJECT *poid = pval;
 155         EC_GROUP *group;
 156
 157         /*
 158          * type == V_ASN1_OBJECT => the parameters are given by an asn1 OID
 159          */
 160         if ((eckey = EC_KEY_new()) == NULL) {
 161             ECerr(EC_F_ECKEY_TYPE2PARAM, ERR_R_MALLOC_FAILURE);
 162             goto ecerr;
 163         }
 164         group = EC_GROUP_new_by_curve_name(OBJ_obj2nid(poid));
 165         if (group == NULL)
 166             goto ecerr;
 167         EC_GROUP_set_asn1_flag(group, OPENSSL_EC_NAMED_CURVE);
 168         if (EC_KEY_set_group(eckey, group) == 0)
 169             goto ecerr;
 170         EC_GROUP_free(group);
 171     } else {
 172         ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
 173         goto ecerr;
 174     }
 175
 176     return eckey;
 177
 178  ecerr:
 179     if (eckey)
 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     if (eckey)
 214         EC_KEY_free(eckey);
 215     return 0;
 216 }
 217
 218 static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 219 {
 220     int r;
 221     const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec);
 222     const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec),
 223         *pb = EC_KEY_get0_public_key(b->pkey.ec);
 224     r = EC_POINT_cmp(group, pa, pb, NULL);
 225     if (r == 0)
 226         return 1;
 227     if (r == 1)
 228         return 0;
 229     return -2;
 230 }
 231
 232 static int eckey_priv_decode(EVP_PKEY *pkey, PKCS8_PRIV_KEY_INFO *p8)
 233 {
 234     const unsigned char *p = NULL;
 235     void *pval;
 236     int ptype, pklen;
 237     EC_KEY *eckey = NULL;
 238     X509_ALGOR *palg;
 239
 240     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 241         return 0;
 242     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 243
 244     eckey = eckey_type2param(ptype, pval);
 245
 246     if (!eckey)
 247         goto ecliberr;
 248
 249     /* We have parameters now set private key */
 250     if (!d2i_ECPrivateKey(&eckey, &p, pklen)) {
 251         ECerr(EC_F_ECKEY_PRIV_DECODE, EC_R_DECODE_ERROR);
 252         goto ecerr;
 253     }
 254
 255     /* calculate public key (if necessary) */
 256     if (EC_KEY_get0_public_key(eckey) == NULL) {
 257         const BIGNUM *priv_key;
 258         const EC_GROUP *group;
 259         EC_POINT *pub_key;
 260         /*
 261          * the public key was not included in the SEC1 private key =>
 262          * calculate the public key
 263          */
 264         group = EC_KEY_get0_group(eckey);
 265         pub_key = EC_POINT_new(group);
 266         if (pub_key == NULL) {
 267             ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 268             goto ecliberr;
 269         }
 270         if (!EC_POINT_copy(pub_key, EC_GROUP_get0_generator(group))) {
 271             EC_POINT_free(pub_key);
 272             ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 273             goto ecliberr;
 274         }
 275         priv_key = EC_KEY_get0_private_key(eckey);
 276         if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, NULL)) {
 277             EC_POINT_free(pub_key);
 278             ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 279             goto ecliberr;
 280         }
 281         if (EC_KEY_set_public_key(eckey, pub_key) == 0) {
 282             EC_POINT_free(pub_key);
 283             ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 284             goto ecliberr;
 285         }
 286         EC_POINT_free(pub_key);
 287     }
 288
 289     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 290     return 1;
 291
 292  ecliberr:
 293     ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 294  ecerr:
 295     if (eckey)
 296         EC_KEY_free(eckey);
 297     return 0;
 298 }
 299
 300 static int eckey_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 301 {
 302     EC_KEY *ec_key;
 303     unsigned char *ep, *p;
 304     int eplen, ptype;
 305     void *pval;
 306     unsigned int tmp_flags, old_flags;
 307
 308     ec_key = pkey->pkey.ec;
 309
 310     if (!eckey_param2type(&ptype, &pval, ec_key)) {
 311         ECerr(EC_F_ECKEY_PRIV_ENCODE, EC_R_DECODE_ERROR);
 312         return 0;
 313     }
 314
 315     /* set the private key */
 316
 317     /*
 318      * do not include the parameters in the SEC1 private key see PKCS#11
 319      * 12.11
 320      */
 321     old_flags = EC_KEY_get_enc_flags(ec_key);
 322     tmp_flags = old_flags | EC_PKEY_NO_PARAMETERS;
 323     EC_KEY_set_enc_flags(ec_key, tmp_flags);
 324     eplen = i2d_ECPrivateKey(ec_key, NULL);
 325     if (!eplen) {
 326         EC_KEY_set_enc_flags(ec_key, old_flags);
 327         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
 328         return 0;
 329     }
 330     ep = (unsigned char *)OPENSSL_malloc(eplen);
 331     if (!ep) {
 332         EC_KEY_set_enc_flags(ec_key, old_flags);
 333         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 334         return 0;
 335     }
 336     p = ep;
 337     if (!i2d_ECPrivateKey(ec_key, &p)) {
 338         EC_KEY_set_enc_flags(ec_key, old_flags);
 339         OPENSSL_free(ep);
 340         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
 341         return 0;
 342     }
 343     /* restore old encoding flags */
 344     EC_KEY_set_enc_flags(ec_key, old_flags);
 345
 346     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0,
 347                          ptype, pval, ep, eplen))
 348         return 0;
 349
 350     return 1;
 351 }
 352
 353 static int int_ec_size(const EVP_PKEY *pkey)
 354 {
 355     return ECDSA_size(pkey->pkey.ec);
 356 }
 357
 358 static int ec_bits(const EVP_PKEY *pkey)
 359 {
 360     BIGNUM *order = BN_new();
 361     const EC_GROUP *group;
 362     int ret;
 363
 364     if (!order) {
 365         ERR_clear_error();
 366         return 0;
 367     }
 368     group = EC_KEY_get0_group(pkey->pkey.ec);
 369     if (!EC_GROUP_get_order(group, order, NULL)) {
 370         ERR_clear_error();
 371         return 0;
 372     }
 373
 374     ret = BN_num_bits(order);
 375     BN_free(order);
 376     return ret;
 377 }
 378
 379 static int ec_security_bits(const EVP_PKEY *pkey)
 380 {
 381     int ecbits = ec_bits(pkey);
 382     if (ecbits >= 512)
 383         return 256;
 384     if (ecbits >= 384)
 385         return 192;
 386     if (ecbits >= 256)
 387         return 128;
 388     if (ecbits >= 224)
 389         return 112;
 390     if (ecbits >= 160)
 391         return 80;
 392     return ecbits / 2;
 393 }
 394
 395 static int ec_missing_parameters(const EVP_PKEY *pkey)
 396 {
 397     if (EC_KEY_get0_group(pkey->pkey.ec) == NULL)
 398         return 1;
 399     return 0;
 400 }
 401
 402 static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 403 {
 404     EC_GROUP *group = EC_GROUP_dup(EC_KEY_get0_group(from->pkey.ec));
 405     if (group == NULL)
 406         return 0;
 407     if (EC_KEY_set_group(to->pkey.ec, group) == 0)
 408         return 0;
 409     EC_GROUP_free(group);
 410     return 1;
 411 }
 412
 413 static int ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 414 {
 415     const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec),
 416         *group_b = EC_KEY_get0_group(b->pkey.ec);
 417     if (EC_GROUP_cmp(group_a, group_b, NULL))
 418         return 0;
 419     else
 420         return 1;
 421 }
 422
 423 static void int_ec_free(EVP_PKEY *pkey)
 424 {
 425     EC_KEY_free(pkey->pkey.ec);
 426 }
 427
 428 static int do_EC_KEY_print(BIO *bp, const EC_KEY *x, int off, int ktype)
 429 {
 430     unsigned char *buffer = NULL;
 431     const char *ecstr;
 432     size_t buf_len = 0, i;
 433     int ret = 0, reason = ERR_R_BIO_LIB;
 434     BIGNUM *pub_key = NULL, *order = NULL;
 435     BN_CTX *ctx = NULL;
 436     const EC_GROUP *group;
 437     const EC_POINT *public_key;
 438     const BIGNUM *priv_key;
 439
 440     if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL) {
 441         reason = ERR_R_PASSED_NULL_PARAMETER;
 442         goto err;
 443     }
 444
 445     ctx = BN_CTX_new();
 446     if (ctx == NULL) {
 447         reason = ERR_R_MALLOC_FAILURE;
 448         goto err;
 449     }
 450
 451     if (ktype > 0) {
 452         public_key = EC_KEY_get0_public_key(x);
 453         if (public_key != NULL) {
 454             if ((pub_key = EC_POINT_point2bn(group, public_key,
 455                                              EC_KEY_get_conv_form(x), NULL,
 456                                              ctx)) == NULL) {
 457                 reason = ERR_R_EC_LIB;
 458                 goto err;
 459             }
 460             buf_len = (size_t)BN_num_bytes(pub_key);
 461         }
 462     }
 463
 464     if (ktype == 2) {
 465         priv_key = EC_KEY_get0_private_key(x);
 466         if (priv_key && (i = (size_t)BN_num_bytes(priv_key)) > buf_len)
 467             buf_len = i;
 468     } else
 469         priv_key = NULL;
 470
 471     if (ktype > 0) {
 472         buf_len += 10;
 473         if ((buffer = OPENSSL_malloc(buf_len)) == NULL) {
 474             reason = ERR_R_MALLOC_FAILURE;
 475             goto err;
 476         }
 477     }
 478     if (ktype == 2)
 479         ecstr = "Private-Key";
 480     else if (ktype == 1)
 481         ecstr = "Public-Key";
 482     else
 483         ecstr = "ECDSA-Parameters";
 484
 485     if (!BIO_indent(bp, off, 128))
 486         goto err;
 487     if ((order = BN_new()) == NULL)
 488         goto err;
 489     if (!EC_GROUP_get_order(group, order, NULL))
 490         goto err;
 491     if (BIO_printf(bp, "%s: (%d bit)\n", ecstr, BN_num_bits(order)) <= 0)
 492         goto err;
 493
 494     if ((priv_key != NULL) && !ASN1_bn_print(bp, "priv:", priv_key,
 495                                              buffer, off))
 496         goto err;
 497     if ((pub_key != NULL) && !ASN1_bn_print(bp, "pub: ", pub_key,
 498                                             buffer, off))
 499         goto err;
 500     if (!ECPKParameters_print(bp, group, off))
 501         goto err;
 502     ret = 1;
 503  err:
 504     if (!ret)
 505         ECerr(EC_F_DO_EC_KEY_PRINT, reason);
 506     if (pub_key)
 507         BN_free(pub_key);
 508     if (order)
 509         BN_free(order);
 510     if (ctx)
 511         BN_CTX_free(ctx);
 512     if (buffer != NULL)
 513         OPENSSL_free(buffer);
 514     return (ret);
 515 }
 516
 517 static int eckey_param_decode(EVP_PKEY *pkey,
 518                               const unsigned char **pder, int derlen)
 519 {
 520     EC_KEY *eckey;
 521     if (!(eckey = d2i_ECParameters(NULL, pder, derlen))) {
 522         ECerr(EC_F_ECKEY_PARAM_DECODE, ERR_R_EC_LIB);
 523         return 0;
 524     }
 525     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 526     return 1;
 527 }
 528
 529 static int eckey_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 530 {
 531     return i2d_ECParameters(pkey->pkey.ec, pder);
 532 }
 533
 534 static int eckey_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 535                              ASN1_PCTX *ctx)
 536 {
 537     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 0);
 538 }
 539
 540 static int eckey_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 541                            ASN1_PCTX *ctx)
 542 {
 543     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 1);
 544 }
 545
 546 static int eckey_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 547                             ASN1_PCTX *ctx)
 548 {
 549     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 2);
 550 }
 551
 552 static int old_ec_priv_decode(EVP_PKEY *pkey,
 553                               const unsigned char **pder, int derlen)
 554 {
 555     EC_KEY *ec;
 556     if (!(ec = d2i_ECPrivateKey(NULL, pder, derlen))) {
 557         ECerr(EC_F_OLD_EC_PRIV_DECODE, EC_R_DECODE_ERROR);
 558         return 0;
 559     }
 560     EVP_PKEY_assign_EC_KEY(pkey, ec);
 561     return 1;
 562 }
 563
 564 static int old_ec_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
 565 {
 566     return i2d_ECPrivateKey(pkey->pkey.ec, pder);
 567 }
 568
 569 static int ec_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 570 {
 571     switch (op) {
 572     case ASN1_PKEY_CTRL_PKCS7_SIGN:
 573         if (arg1 == 0) {
 574             int snid, hnid;
 575             X509_ALGOR *alg1, *alg2;
 576             PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2);
 577             if (alg1 == NULL || alg1->algorithm == NULL)
 578                 return -1;
 579             hnid = OBJ_obj2nid(alg1->algorithm);
 580             if (hnid == NID_undef)
 581                 return -1;
 582             if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 583                 return -1;
 584             X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 585         }
 586         return 1;
 587 #ifndef OPENSSL_NO_CMS
 588     case ASN1_PKEY_CTRL_CMS_SIGN:
 589         if (arg1 == 0) {
 590             int snid, hnid;
 591             X509_ALGOR *alg1, *alg2;
 592             CMS_SignerInfo_get0_algs(arg2, NULL, NULL, &alg1, &alg2);
 593             if (alg1 == NULL || alg1->algorithm == NULL)
 594                 return -1;
 595             hnid = OBJ_obj2nid(alg1->algorithm);
 596             if (hnid == NID_undef)
 597                 return -1;
 598             if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 599                 return -1;
 600             X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 601         }
 602         return 1;
 603
 604     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 605         if (arg1 == 1)
 606             return ecdh_cms_decrypt(arg2);
 607         else if (arg1 == 0)
 608             return ecdh_cms_encrypt(arg2);
 609         return -2;
 610
 611     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 612         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 613         return 1;
 614 #endif
 615
 616     case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
 617         *(int *)arg2 = NID_sha256;
 618         return 2;
 619
 620     default:
 621         return -2;
 622
 623     }
 624
 625 }
 626
 627 const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = {
 628     EVP_PKEY_EC,
 629     EVP_PKEY_EC,
 630     0,
 631     "EC",
 632     "OpenSSL EC algorithm",
 633
 634     eckey_pub_decode,
 635     eckey_pub_encode,
 636     eckey_pub_cmp,
 637     eckey_pub_print,
 638
 639     eckey_priv_decode,
 640     eckey_priv_encode,
 641     eckey_priv_print,
 642
 643     int_ec_size,
 644     ec_bits,
 645     ec_security_bits,
 646
 647     eckey_param_decode,
 648     eckey_param_encode,
 649     ec_missing_parameters,
 650     ec_copy_parameters,
 651     ec_cmp_parameters,
 652     eckey_param_print,
 653     0,
 654
 655     int_ec_free,
 656     ec_pkey_ctrl,
 657     old_ec_priv_decode,
 658     old_ec_priv_encode
 659 };
 660
 661 #ifndef OPENSSL_NO_CMS
 662
 663 static int ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 664                                 X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 665 {
 666     ASN1_OBJECT *aoid;
 667     int atype;
 668     void *aval;
 669     int rv = 0;
 670     EVP_PKEY *pkpeer = NULL;
 671     EC_KEY *ecpeer = NULL;
 672     const unsigned char *p;
 673     int plen;
 674     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 675     if (OBJ_obj2nid(aoid) != NID_X9_62_id_ecPublicKey)
 676         goto err;
 677     /* If absent parameters get group from main key */
 678     if (atype == V_ASN1_UNDEF || atype == V_ASN1_NULL) {
 679         const EC_GROUP *grp;
 680         EVP_PKEY *pk;
 681         pk = EVP_PKEY_CTX_get0_pkey(pctx);
 682         if (!pk)
 683             goto err;
 684         grp = EC_KEY_get0_group(pk->pkey.ec);
 685         ecpeer = EC_KEY_new();
 686         if (!ecpeer)
 687             goto err;
 688         if (!EC_KEY_set_group(ecpeer, grp))
 689             goto err;
 690     } else {
 691         ecpeer = eckey_type2param(atype, aval);
 692         if (!ecpeer)
 693             goto err;
 694     }
 695     /* We have parameters now set public key */
 696     plen = ASN1_STRING_length(pubkey);
 697     p = ASN1_STRING_data(pubkey);
 698     if (!p || !plen)
 699         goto err;
 700     if (!o2i_ECPublicKey(&ecpeer, &p, plen))
 701         goto err;
 702     pkpeer = EVP_PKEY_new();
 703     if (!pkpeer)
 704         goto err;
 705     EVP_PKEY_set1_EC_KEY(pkpeer, ecpeer);
 706     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 707         rv = 1;
 708  err:
 709     if (ecpeer)
 710         EC_KEY_free(ecpeer);
 711     if (pkpeer)
 712         EVP_PKEY_free(pkpeer);
 713     return rv;
 714 }
 715
 716 /* Set KDF parameters based on KDF NID */
 717 static int ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid)
 718 {
 719     int kdf_nid, kdfmd_nid, cofactor;
 720     const EVP_MD *kdf_md;
 721     if (eckdf_nid == NID_undef)
 722         return 0;
 723
 724     /* Lookup KDF type, cofactor mode and digest */
 725     if (!OBJ_find_sigid_algs(eckdf_nid, &kdfmd_nid, &kdf_nid))
 726         return 0;
 727
 728     if (kdf_nid == NID_dh_std_kdf)
 729         cofactor = 0;
 730     else if (kdf_nid == NID_dh_cofactor_kdf)
 731         cofactor = 1;
 732     else
 733         return 0;
 734
 735     if (EVP_PKEY_CTX_set_ecdh_cofactor_mode(pctx, cofactor) <= 0)
 736         return 0;
 737
 738     if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, EVP_PKEY_ECDH_KDF_X9_62) <= 0)
 739         return 0;
 740
 741     kdf_md = EVP_get_digestbynid(kdfmd_nid);
 742     if (!kdf_md)
 743         return 0;
 744
 745     if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
 746         return 0;
 747     return 1;
 748 }
 749
 750 static int ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 751 {
 752     int rv = 0;
 753
 754     X509_ALGOR *alg, *kekalg = NULL;
 755     ASN1_OCTET_STRING *ukm;
 756     const unsigned char *p;
 757     unsigned char *der = NULL;
 758     int plen, keylen;
 759     const EVP_CIPHER *kekcipher;
 760     EVP_CIPHER_CTX *kekctx;
 761
 762     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 763         return 0;
 764
 765     if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) {
 766         ECerr(EC_F_ECDH_CMS_SET_SHARED_INFO, EC_R_KDF_PARAMETER_ERROR);
 767         return 0;
 768     }
 769
 770     if (alg->parameter->type != V_ASN1_SEQUENCE)
 771         return 0;
 772
 773     p = alg->parameter->value.sequence->data;
 774     plen = alg->parameter->value.sequence->length;
 775     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 776     if (!kekalg)
 777         goto err;
 778     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 779     if (!kekctx)
 780         goto err;
 781     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 782     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 783         goto err;
 784     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 785         goto err;
 786     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 787         goto err;
 788
 789     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 790     if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
 791         goto err;
 792
 793     plen = CMS_SharedInfo_encode(&der, kekalg, ukm, keylen);
 794
 795     if (!plen)
 796         goto err;
 797
 798     if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
 799         goto err;
 800     der = NULL;
 801
 802     rv = 1;
 803  err:
 804     if (kekalg)
 805         X509_ALGOR_free(kekalg);
 806     if (der)
 807         OPENSSL_free(der);
 808     return rv;
 809 }
 810
 811 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri)
 812 {
 813     EVP_PKEY_CTX *pctx;
 814     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 815     if (!pctx)
 816         return 0;
 817     /* See if we need to set peer key */
 818     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 819         X509_ALGOR *alg;
 820         ASN1_BIT_STRING *pubkey;
 821         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 822                                                  NULL, NULL, NULL))
 823             return 0;
 824         if (!alg || !pubkey)
 825             return 0;
 826         if (!ecdh_cms_set_peerkey(pctx, alg, pubkey)) {
 827             ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_PEER_KEY_ERROR);
 828             return 0;
 829         }
 830     }
 831     /* Set ECDH derivation parameters and initialise unwrap context */
 832     if (!ecdh_cms_set_shared_info(pctx, ri)) {
 833         ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_SHARED_INFO_ERROR);
 834         return 0;
 835     }
 836     return 1;
 837 }
 838
 839 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri)
 840 {
 841     EVP_PKEY_CTX *pctx;
 842     EVP_PKEY *pkey;
 843     EVP_CIPHER_CTX *ctx;
 844     int keylen;
 845     X509_ALGOR *talg, *wrap_alg = NULL;
 846     ASN1_OBJECT *aoid;
 847     ASN1_BIT_STRING *pubkey;
 848     ASN1_STRING *wrap_str;
 849     ASN1_OCTET_STRING *ukm;
 850     unsigned char *penc = NULL;
 851     int penclen;
 852     int rv = 0;
 853     int ecdh_nid, kdf_type, kdf_nid, wrap_nid;
 854     const EVP_MD *kdf_md;
 855     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 856     if (!pctx)
 857         return 0;
 858     /* Get ephemeral key */
 859     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 860     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 861                                              NULL, NULL, NULL))
 862         goto err;
 863     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 864     /* Is everything uninitialised? */
 865     if (aoid == OBJ_nid2obj(NID_undef)) {
 866
 867         EC_KEY *eckey = pkey->pkey.ec;
 868         /* Set the key */
 869         unsigned char *p;
 870
 871         penclen = i2o_ECPublicKey(eckey, NULL);
 872         if (penclen <= 0)
 873             goto err;
 874         penc = OPENSSL_malloc(penclen);
 875         if (!penc)
 876             goto err;
 877         p = penc;
 878         penclen = i2o_ECPublicKey(eckey, &p);
 879         if (penclen <= 0)
 880             goto err;
 881         ASN1_STRING_set0(pubkey, penc, penclen);
 882         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 883         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 884
 885         penc = NULL;
 886         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_X9_62_id_ecPublicKey),
 887                         V_ASN1_UNDEF, NULL);
 888     }
 889
 890     /* See if custom paraneters set */
 891     kdf_type = EVP_PKEY_CTX_get_ecdh_kdf_type(pctx);
 892     if (kdf_type <= 0)
 893         goto err;
 894     if (!EVP_PKEY_CTX_get_ecdh_kdf_md(pctx, &kdf_md))
 895         goto err;
 896     ecdh_nid = EVP_PKEY_CTX_get_ecdh_cofactor_mode(pctx);
 897     if (ecdh_nid < 0)
 898         goto err;
 899     else if (ecdh_nid == 0)
 900         ecdh_nid = NID_dh_std_kdf;
 901     else if (ecdh_nid == 1)
 902         ecdh_nid = NID_dh_cofactor_kdf;
 903
 904     if (kdf_type == EVP_PKEY_ECDH_KDF_NONE) {
 905         kdf_type = EVP_PKEY_ECDH_KDF_X9_62;
 906         if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0)
 907             goto err;
 908     } else
 909         /* Uknown KDF */
 910         goto err;
 911     if (kdf_md == NULL) {
 912         /* Fixme later for better MD */
 913         kdf_md = EVP_sha1();
 914         if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
 915             goto err;
 916     }
 917
 918     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 919         goto err;
 920
 921     /* Lookup NID for KDF+cofactor+digest */
 922
 923     if (!OBJ_find_sigid_by_algs(&kdf_nid, EVP_MD_type(kdf_md), ecdh_nid))
 924         goto err;
 925     /* Get wrap NID */
 926     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 927     wrap_nid = EVP_CIPHER_CTX_type(ctx);
 928     keylen = EVP_CIPHER_CTX_key_length(ctx);
 929
 930     /* Package wrap algorithm in an AlgorithmIdentifier */
 931
 932     wrap_alg = X509_ALGOR_new();
 933     if (!wrap_alg)
 934         goto err;
 935     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 936     wrap_alg->parameter = ASN1_TYPE_new();
 937     if (!wrap_alg->parameter)
 938         goto err;
 939     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 940         goto err;
 941     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
 942         ASN1_TYPE_free(wrap_alg->parameter);
 943         wrap_alg->parameter = NULL;
 944     }
 945
 946     if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
 947         goto err;
 948
 949     penclen = CMS_SharedInfo_encode(&penc, wrap_alg, ukm, keylen);
 950
 951     if (!penclen)
 952         goto err;
 953
 954     if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, penc, penclen) <= 0)
 955         goto err;
 956     penc = NULL;
 957
 958     /*
 959      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
 960      * of another AlgorithmIdentifier.
 961      */
 962     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 963     if (!penc || !penclen)
 964         goto err;
 965     wrap_str = ASN1_STRING_new();
 966     if (!wrap_str)
 967         goto err;
 968     ASN1_STRING_set0(wrap_str, penc, penclen);
 969     penc = NULL;
 970     X509_ALGOR_set0(talg, OBJ_nid2obj(kdf_nid), V_ASN1_SEQUENCE, wrap_str);
 971
 972     rv = 1;
 973
 974  err:
 975     if (penc)
 976         OPENSSL_free(penc);
 977     if (wrap_alg)
 978         X509_ALGOR_free(wrap_alg);
 979     return rv;
 980 }
 981
 982 #endif