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 #include <openssl/cms.h>
  65 #include <openssl/asn1t.h>
  66 #include "internal/asn1_int.h"
  67 #include "internal/evp_int.h"
  68
  69 #ifndef OPENSSL_NO_CMS
  70 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri);
  71 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri);
  72 #endif
  73
  74 static int eckey_param2type(int *pptype, void **ppval, EC_KEY *ec_key)
  75 {
  76     const EC_GROUP *group;
  77     int nid;
  78     if (ec_key == NULL || (group = EC_KEY_get0_group(ec_key)) == NULL) {
  79         ECerr(EC_F_ECKEY_PARAM2TYPE, EC_R_MISSING_PARAMETERS);
  80         return 0;
  81     }
  82     if (EC_GROUP_get_asn1_flag(group)
  83         && (nid = EC_GROUP_get_curve_name(group)))
  84         /* we have a 'named curve' => just set the OID */
  85     {
  86         *ppval = OBJ_nid2obj(nid);
  87         *pptype = V_ASN1_OBJECT;
  88     } else {                    /* explicit parameters */
  89
  90         ASN1_STRING *pstr = NULL;
  91         pstr = ASN1_STRING_new();
  92         if (pstr == NULL)
  93             return 0;
  94         pstr->length = i2d_ECParameters(ec_key, &pstr->data);
  95         if (pstr->length <= 0) {
  96             ASN1_STRING_free(pstr);
  97             ECerr(EC_F_ECKEY_PARAM2TYPE, ERR_R_EC_LIB);
  98             return 0;
  99         }
 100         *ppval = pstr;
 101         *pptype = V_ASN1_SEQUENCE;
 102     }
 103     return 1;
 104 }
 105
 106 static int eckey_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 107 {
 108     EC_KEY *ec_key = pkey->pkey.ec;
 109     void *pval = NULL;
 110     int ptype;
 111     unsigned char *penc = NULL, *p;
 112     int penclen;
 113
 114     if (!eckey_param2type(&ptype, &pval, ec_key)) {
 115         ECerr(EC_F_ECKEY_PUB_ENCODE, ERR_R_EC_LIB);
 116         return 0;
 117     }
 118     penclen = i2o_ECPublicKey(ec_key, NULL);
 119     if (penclen <= 0)
 120         goto err;
 121     penc = OPENSSL_malloc(penclen);
 122     if (penc == NULL)
 123         goto err;
 124     p = penc;
 125     penclen = i2o_ECPublicKey(ec_key, &p);
 126     if (penclen <= 0)
 127         goto err;
 128     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(EVP_PKEY_EC),
 129                                ptype, pval, penc, penclen))
 130         return 1;
 131  err:
 132     if (ptype == V_ASN1_OBJECT)
 133         ASN1_OBJECT_free(pval);
 134     else
 135         ASN1_STRING_free(pval);
 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)) == NULL) {
 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     EC_KEY_free(eckey);
 180     return NULL;
 181 }
 182
 183 static int eckey_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
 184 {
 185     const unsigned char *p = NULL;
 186     void *pval;
 187     int ptype, pklen;
 188     EC_KEY *eckey = NULL;
 189     X509_ALGOR *palg;
 190
 191     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
 192         return 0;
 193     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 194
 195     eckey = eckey_type2param(ptype, pval);
 196
 197     if (!eckey) {
 198         ECerr(EC_F_ECKEY_PUB_DECODE, ERR_R_EC_LIB);
 199         return 0;
 200     }
 201
 202     /* We have parameters now set public key */
 203     if (!o2i_ECPublicKey(&eckey, &p, pklen)) {
 204         ECerr(EC_F_ECKEY_PUB_DECODE, EC_R_DECODE_ERROR);
 205         goto ecerr;
 206     }
 207
 208     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 209     return 1;
 210
 211  ecerr:
 212     EC_KEY_free(eckey);
 213     return 0;
 214 }
 215
 216 static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 217 {
 218     int r;
 219     const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec);
 220     const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec),
 221         *pb = EC_KEY_get0_public_key(b->pkey.ec);
 222     r = EC_POINT_cmp(group, pa, pb, NULL);
 223     if (r == 0)
 224         return 1;
 225     if (r == 1)
 226         return 0;
 227     return -2;
 228 }
 229
 230 static int eckey_priv_decode(EVP_PKEY *pkey, PKCS8_PRIV_KEY_INFO *p8)
 231 {
 232     const unsigned char *p = NULL;
 233     void *pval;
 234     int ptype, pklen;
 235     EC_KEY *eckey = NULL;
 236     X509_ALGOR *palg;
 237
 238     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 239         return 0;
 240     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 241
 242     eckey = eckey_type2param(ptype, pval);
 243
 244     if (!eckey)
 245         goto ecliberr;
 246
 247     /* We have parameters now set private key */
 248     if (!d2i_ECPrivateKey(&eckey, &p, pklen)) {
 249         ECerr(EC_F_ECKEY_PRIV_DECODE, EC_R_DECODE_ERROR);
 250         goto ecerr;
 251     }
 252
 253     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 254     return 1;
 255
 256  ecliberr:
 257     ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 258  ecerr:
 259     EC_KEY_free(eckey);
 260     return 0;
 261 }
 262
 263 static int eckey_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 264 {
 265     EC_KEY *ec_key;
 266     unsigned char *ep, *p;
 267     int eplen, ptype;
 268     void *pval;
 269     unsigned int tmp_flags, old_flags;
 270
 271     ec_key = pkey->pkey.ec;
 272
 273     if (!eckey_param2type(&ptype, &pval, ec_key)) {
 274         ECerr(EC_F_ECKEY_PRIV_ENCODE, EC_R_DECODE_ERROR);
 275         return 0;
 276     }
 277
 278     /* set the private key */
 279
 280     /*
 281      * do not include the parameters in the SEC1 private key see PKCS#11
 282      * 12.11
 283      */
 284     old_flags = EC_KEY_get_enc_flags(ec_key);
 285     tmp_flags = old_flags | EC_PKEY_NO_PARAMETERS;
 286     EC_KEY_set_enc_flags(ec_key, tmp_flags);
 287     eplen = i2d_ECPrivateKey(ec_key, NULL);
 288     if (!eplen) {
 289         EC_KEY_set_enc_flags(ec_key, old_flags);
 290         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
 291         return 0;
 292     }
 293     ep = OPENSSL_malloc(eplen);
 294     if (ep == NULL) {
 295         EC_KEY_set_enc_flags(ec_key, old_flags);
 296         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 297         return 0;
 298     }
 299     p = ep;
 300     if (!i2d_ECPrivateKey(ec_key, &p)) {
 301         EC_KEY_set_enc_flags(ec_key, old_flags);
 302         OPENSSL_free(ep);
 303         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
 304         return 0;
 305     }
 306     /* restore old encoding flags */
 307     EC_KEY_set_enc_flags(ec_key, old_flags);
 308
 309     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0,
 310                          ptype, pval, ep, eplen))
 311         return 0;
 312
 313     return 1;
 314 }
 315
 316 static int int_ec_size(const EVP_PKEY *pkey)
 317 {
 318     return ECDSA_size(pkey->pkey.ec);
 319 }
 320
 321 static int ec_bits(const EVP_PKEY *pkey)
 322 {
 323     return EC_GROUP_order_bits(EC_KEY_get0_group(pkey->pkey.ec));
 324 }
 325
 326 static int ec_security_bits(const EVP_PKEY *pkey)
 327 {
 328     int ecbits = ec_bits(pkey);
 329     if (ecbits >= 512)
 330         return 256;
 331     if (ecbits >= 384)
 332         return 192;
 333     if (ecbits >= 256)
 334         return 128;
 335     if (ecbits >= 224)
 336         return 112;
 337     if (ecbits >= 160)
 338         return 80;
 339     return ecbits / 2;
 340 }
 341
 342 static int ec_missing_parameters(const EVP_PKEY *pkey)
 343 {
 344     if (EC_KEY_get0_group(pkey->pkey.ec) == NULL)
 345         return 1;
 346     return 0;
 347 }
 348
 349 static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 350 {
 351     EC_GROUP *group = EC_GROUP_dup(EC_KEY_get0_group(from->pkey.ec));
 352     if (group == NULL)
 353         return 0;
 354     if (to->pkey.ec == NULL) {
 355         to->pkey.ec = EC_KEY_new();
 356         if (to->pkey.ec == NULL)
 357             return 0;
 358     }
 359     if (EC_KEY_set_group(to->pkey.ec, group) == 0)
 360         return 0;
 361     EC_GROUP_free(group);
 362     return 1;
 363 }
 364
 365 static int ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 366 {
 367     const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec),
 368         *group_b = EC_KEY_get0_group(b->pkey.ec);
 369     if (EC_GROUP_cmp(group_a, group_b, NULL))
 370         return 0;
 371     else
 372         return 1;
 373 }
 374
 375 static void int_ec_free(EVP_PKEY *pkey)
 376 {
 377     EC_KEY_free(pkey->pkey.ec);
 378 }
 379
 380 typedef enum {
 381     EC_KEY_PRINT_PRIVATE,
 382     EC_KEY_PRINT_PUBLIC,
 383     EC_KEY_PRINT_PARAM
 384 } ec_print_t;
 385
 386 static int do_EC_KEY_print(BIO *bp, const EC_KEY *x, int off, ec_print_t ktype)
 387 {
 388     const char *ecstr;
 389     unsigned char *priv = NULL, *pub = NULL;
 390     size_t privlen = 0, publen = 0;
 391     int ret = 0;
 392     const EC_GROUP *group;
 393
 394     if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL) {
 395         ECerr(EC_F_DO_EC_KEY_PRINT, ERR_R_PASSED_NULL_PARAMETER);
 396         return 0;
 397     }
 398
 399     if (ktype != EC_KEY_PRINT_PARAM) {
 400         publen = EC_KEY_key2buf(x, EC_KEY_get_conv_form(x), &pub, NULL);
 401         if (publen == 0)
 402             goto err;
 403     }
 404
 405     if (ktype == EC_KEY_PRINT_PRIVATE && EC_KEY_get0_private_key(x) != NULL) {
 406         privlen = EC_KEY_priv2buf(x, &priv);
 407         if (privlen == 0)
 408             goto err;
 409     }
 410
 411     if (ktype == EC_KEY_PRINT_PRIVATE)
 412         ecstr = "Private-Key";
 413     else if (ktype == EC_KEY_PRINT_PUBLIC)
 414         ecstr = "Public-Key";
 415     else
 416         ecstr = "ECDSA-Parameters";
 417
 418     if (!BIO_indent(bp, off, 128))
 419         goto err;
 420     if (BIO_printf(bp, "%s: (%d bit)\n", ecstr,
 421                    EC_GROUP_order_bits(group)) <= 0)
 422         goto err;
 423
 424     if (privlen != 0) {
 425         if (BIO_printf(bp, "%*spriv:\n", off, "") <= 0)
 426             goto err;
 427         if (ASN1_buf_print(bp, priv, privlen, off + 4) == 0)
 428             goto err;
 429     }
 430
 431     if (publen != 0) {
 432         if (BIO_printf(bp, "%*spub:\n", off, "") <= 0)
 433             goto err;
 434         if (ASN1_buf_print(bp, pub, publen, off + 4) == 0)
 435             goto err;
 436     }
 437
 438     if (!ECPKParameters_print(bp, group, off))
 439         goto err;
 440     ret = 1;
 441  err:
 442     if (!ret)
 443         ECerr(EC_F_DO_EC_KEY_PRINT, ERR_R_EC_LIB);
 444     OPENSSL_clear_free(priv, privlen);
 445     OPENSSL_free(pub);
 446     return ret;
 447 }
 448
 449 static int eckey_param_decode(EVP_PKEY *pkey,
 450                               const unsigned char **pder, int derlen)
 451 {
 452     EC_KEY *eckey;
 453
 454     if ((eckey = d2i_ECParameters(NULL, pder, derlen)) == NULL) {
 455         ECerr(EC_F_ECKEY_PARAM_DECODE, ERR_R_EC_LIB);
 456         return 0;
 457     }
 458     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 459     return 1;
 460 }
 461
 462 static int eckey_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 463 {
 464     return i2d_ECParameters(pkey->pkey.ec, pder);
 465 }
 466
 467 static int eckey_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 468                              ASN1_PCTX *ctx)
 469 {
 470     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PARAM);
 471 }
 472
 473 static int eckey_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 474                            ASN1_PCTX *ctx)
 475 {
 476     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PUBLIC);
 477 }
 478
 479 static int eckey_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 480                             ASN1_PCTX *ctx)
 481 {
 482     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PRIVATE);
 483 }
 484
 485 static int old_ec_priv_decode(EVP_PKEY *pkey,
 486                               const unsigned char **pder, int derlen)
 487 {
 488     EC_KEY *ec;
 489
 490     if ((ec = d2i_ECPrivateKey(NULL, pder, derlen)) == NULL) {
 491         ECerr(EC_F_OLD_EC_PRIV_DECODE, EC_R_DECODE_ERROR);
 492         return 0;
 493     }
 494     EVP_PKEY_assign_EC_KEY(pkey, ec);
 495     return 1;
 496 }
 497
 498 static int old_ec_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
 499 {
 500     return i2d_ECPrivateKey(pkey->pkey.ec, pder);
 501 }
 502
 503 static int ec_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 504 {
 505     switch (op) {
 506     case ASN1_PKEY_CTRL_PKCS7_SIGN:
 507         if (arg1 == 0) {
 508             int snid, hnid;
 509             X509_ALGOR *alg1, *alg2;
 510             PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2);
 511             if (alg1 == NULL || alg1->algorithm == NULL)
 512                 return -1;
 513             hnid = OBJ_obj2nid(alg1->algorithm);
 514             if (hnid == NID_undef)
 515                 return -1;
 516             if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 517                 return -1;
 518             X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 519         }
 520         return 1;
 521 #ifndef OPENSSL_NO_CMS
 522     case ASN1_PKEY_CTRL_CMS_SIGN:
 523         if (arg1 == 0) {
 524             int snid, hnid;
 525             X509_ALGOR *alg1, *alg2;
 526             CMS_SignerInfo_get0_algs(arg2, NULL, NULL, &alg1, &alg2);
 527             if (alg1 == NULL || alg1->algorithm == NULL)
 528                 return -1;
 529             hnid = OBJ_obj2nid(alg1->algorithm);
 530             if (hnid == NID_undef)
 531                 return -1;
 532             if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 533                 return -1;
 534             X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 535         }
 536         return 1;
 537
 538     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 539         if (arg1 == 1)
 540             return ecdh_cms_decrypt(arg2);
 541         else if (arg1 == 0)
 542             return ecdh_cms_encrypt(arg2);
 543         return -2;
 544
 545     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 546         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 547         return 1;
 548 #endif
 549
 550     case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
 551         *(int *)arg2 = NID_sha256;
 552         return 2;
 553
 554     default:
 555         return -2;
 556
 557     }
 558
 559 }
 560
 561 const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = {
 562     EVP_PKEY_EC,
 563     EVP_PKEY_EC,
 564     0,
 565     "EC",
 566     "OpenSSL EC algorithm",
 567
 568     eckey_pub_decode,
 569     eckey_pub_encode,
 570     eckey_pub_cmp,
 571     eckey_pub_print,
 572
 573     eckey_priv_decode,
 574     eckey_priv_encode,
 575     eckey_priv_print,
 576
 577     int_ec_size,
 578     ec_bits,
 579     ec_security_bits,
 580
 581     eckey_param_decode,
 582     eckey_param_encode,
 583     ec_missing_parameters,
 584     ec_copy_parameters,
 585     ec_cmp_parameters,
 586     eckey_param_print,
 587     0,
 588
 589     int_ec_free,
 590     ec_pkey_ctrl,
 591     old_ec_priv_decode,
 592     old_ec_priv_encode
 593 };
 594
 595 #ifndef OPENSSL_NO_CMS
 596
 597 static int ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 598                                 X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 599 {
 600     ASN1_OBJECT *aoid;
 601     int atype;
 602     void *aval;
 603     int rv = 0;
 604     EVP_PKEY *pkpeer = NULL;
 605     EC_KEY *ecpeer = NULL;
 606     const unsigned char *p;
 607     int plen;
 608     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 609     if (OBJ_obj2nid(aoid) != NID_X9_62_id_ecPublicKey)
 610         goto err;
 611     /* If absent parameters get group from main key */
 612     if (atype == V_ASN1_UNDEF || atype == V_ASN1_NULL) {
 613         const EC_GROUP *grp;
 614         EVP_PKEY *pk;
 615         pk = EVP_PKEY_CTX_get0_pkey(pctx);
 616         if (!pk)
 617             goto err;
 618         grp = EC_KEY_get0_group(pk->pkey.ec);
 619         ecpeer = EC_KEY_new();
 620         if (ecpeer == NULL)
 621             goto err;
 622         if (!EC_KEY_set_group(ecpeer, grp))
 623             goto err;
 624     } else {
 625         ecpeer = eckey_type2param(atype, aval);
 626         if (!ecpeer)
 627             goto err;
 628     }
 629     /* We have parameters now set public key */
 630     plen = ASN1_STRING_length(pubkey);
 631     p = ASN1_STRING_data(pubkey);
 632     if (!p || !plen)
 633         goto err;
 634     if (!o2i_ECPublicKey(&ecpeer, &p, plen))
 635         goto err;
 636     pkpeer = EVP_PKEY_new();
 637     if (pkpeer == NULL)
 638         goto err;
 639     EVP_PKEY_set1_EC_KEY(pkpeer, ecpeer);
 640     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 641         rv = 1;
 642  err:
 643     EC_KEY_free(ecpeer);
 644     EVP_PKEY_free(pkpeer);
 645     return rv;
 646 }
 647
 648 /* Set KDF parameters based on KDF NID */
 649 static int ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid)
 650 {
 651     int kdf_nid, kdfmd_nid, cofactor;
 652     const EVP_MD *kdf_md;
 653     if (eckdf_nid == NID_undef)
 654         return 0;
 655
 656     /* Lookup KDF type, cofactor mode and digest */
 657     if (!OBJ_find_sigid_algs(eckdf_nid, &kdfmd_nid, &kdf_nid))
 658         return 0;
 659
 660     if (kdf_nid == NID_dh_std_kdf)
 661         cofactor = 0;
 662     else if (kdf_nid == NID_dh_cofactor_kdf)
 663         cofactor = 1;
 664     else
 665         return 0;
 666
 667     if (EVP_PKEY_CTX_set_ecdh_cofactor_mode(pctx, cofactor) <= 0)
 668         return 0;
 669
 670     if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, EVP_PKEY_ECDH_KDF_X9_62) <= 0)
 671         return 0;
 672
 673     kdf_md = EVP_get_digestbynid(kdfmd_nid);
 674     if (!kdf_md)
 675         return 0;
 676
 677     if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
 678         return 0;
 679     return 1;
 680 }
 681
 682 static int ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 683 {
 684     int rv = 0;
 685
 686     X509_ALGOR *alg, *kekalg = NULL;
 687     ASN1_OCTET_STRING *ukm;
 688     const unsigned char *p;
 689     unsigned char *der = NULL;
 690     int plen, keylen;
 691     const EVP_CIPHER *kekcipher;
 692     EVP_CIPHER_CTX *kekctx;
 693
 694     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 695         return 0;
 696
 697     if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) {
 698         ECerr(EC_F_ECDH_CMS_SET_SHARED_INFO, EC_R_KDF_PARAMETER_ERROR);
 699         return 0;
 700     }
 701
 702     if (alg->parameter->type != V_ASN1_SEQUENCE)
 703         return 0;
 704
 705     p = alg->parameter->value.sequence->data;
 706     plen = alg->parameter->value.sequence->length;
 707     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 708     if (!kekalg)
 709         goto err;
 710     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 711     if (!kekctx)
 712         goto err;
 713     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 714     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 715         goto err;
 716     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 717         goto err;
 718     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 719         goto err;
 720
 721     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 722     if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
 723         goto err;
 724
 725     plen = CMS_SharedInfo_encode(&der, kekalg, ukm, keylen);
 726
 727     if (!plen)
 728         goto err;
 729
 730     if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
 731         goto err;
 732     der = NULL;
 733
 734     rv = 1;
 735  err:
 736     X509_ALGOR_free(kekalg);
 737     OPENSSL_free(der);
 738     return rv;
 739 }
 740
 741 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri)
 742 {
 743     EVP_PKEY_CTX *pctx;
 744     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 745     if (!pctx)
 746         return 0;
 747     /* See if we need to set peer key */
 748     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 749         X509_ALGOR *alg;
 750         ASN1_BIT_STRING *pubkey;
 751         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 752                                                  NULL, NULL, NULL))
 753             return 0;
 754         if (!alg || !pubkey)
 755             return 0;
 756         if (!ecdh_cms_set_peerkey(pctx, alg, pubkey)) {
 757             ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_PEER_KEY_ERROR);
 758             return 0;
 759         }
 760     }
 761     /* Set ECDH derivation parameters and initialise unwrap context */
 762     if (!ecdh_cms_set_shared_info(pctx, ri)) {
 763         ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_SHARED_INFO_ERROR);
 764         return 0;
 765     }
 766     return 1;
 767 }
 768
 769 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri)
 770 {
 771     EVP_PKEY_CTX *pctx;
 772     EVP_PKEY *pkey;
 773     EVP_CIPHER_CTX *ctx;
 774     int keylen;
 775     X509_ALGOR *talg, *wrap_alg = NULL;
 776     ASN1_OBJECT *aoid;
 777     ASN1_BIT_STRING *pubkey;
 778     ASN1_STRING *wrap_str;
 779     ASN1_OCTET_STRING *ukm;
 780     unsigned char *penc = NULL;
 781     int penclen;
 782     int rv = 0;
 783     int ecdh_nid, kdf_type, kdf_nid, wrap_nid;
 784     const EVP_MD *kdf_md;
 785     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 786     if (!pctx)
 787         return 0;
 788     /* Get ephemeral key */
 789     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 790     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 791                                              NULL, NULL, NULL))
 792         goto err;
 793     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 794     /* Is everything uninitialised? */
 795     if (aoid == OBJ_nid2obj(NID_undef)) {
 796
 797         EC_KEY *eckey = pkey->pkey.ec;
 798         /* Set the key */
 799         unsigned char *p;
 800
 801         penclen = i2o_ECPublicKey(eckey, NULL);
 802         if (penclen <= 0)
 803             goto err;
 804         penc = OPENSSL_malloc(penclen);
 805         if (penc == NULL)
 806             goto err;
 807         p = penc;
 808         penclen = i2o_ECPublicKey(eckey, &p);
 809         if (penclen <= 0)
 810             goto err;
 811         ASN1_STRING_set0(pubkey, penc, penclen);
 812         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 813         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 814
 815         penc = NULL;
 816         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_X9_62_id_ecPublicKey),
 817                         V_ASN1_UNDEF, NULL);
 818     }
 819
 820     /* See if custom parameters set */
 821     kdf_type = EVP_PKEY_CTX_get_ecdh_kdf_type(pctx);
 822     if (kdf_type <= 0)
 823         goto err;
 824     if (!EVP_PKEY_CTX_get_ecdh_kdf_md(pctx, &kdf_md))
 825         goto err;
 826     ecdh_nid = EVP_PKEY_CTX_get_ecdh_cofactor_mode(pctx);
 827     if (ecdh_nid < 0)
 828         goto err;
 829     else if (ecdh_nid == 0)
 830         ecdh_nid = NID_dh_std_kdf;
 831     else if (ecdh_nid == 1)
 832         ecdh_nid = NID_dh_cofactor_kdf;
 833
 834     if (kdf_type == EVP_PKEY_ECDH_KDF_NONE) {
 835         kdf_type = EVP_PKEY_ECDH_KDF_X9_62;
 836         if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0)
 837             goto err;
 838     } else
 839         /* Unknown KDF */
 840         goto err;
 841     if (kdf_md == NULL) {
 842         /* Fixme later for better MD */
 843         kdf_md = EVP_sha1();
 844         if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
 845             goto err;
 846     }
 847
 848     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 849         goto err;
 850
 851     /* Lookup NID for KDF+cofactor+digest */
 852
 853     if (!OBJ_find_sigid_by_algs(&kdf_nid, EVP_MD_type(kdf_md), ecdh_nid))
 854         goto err;
 855     /* Get wrap NID */
 856     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 857     wrap_nid = EVP_CIPHER_CTX_type(ctx);
 858     keylen = EVP_CIPHER_CTX_key_length(ctx);
 859
 860     /* Package wrap algorithm in an AlgorithmIdentifier */
 861
 862     wrap_alg = X509_ALGOR_new();
 863     if (wrap_alg == NULL)
 864         goto err;
 865     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 866     wrap_alg->parameter = ASN1_TYPE_new();
 867     if (wrap_alg->parameter == NULL)
 868         goto err;
 869     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 870         goto err;
 871     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
 872         ASN1_TYPE_free(wrap_alg->parameter);
 873         wrap_alg->parameter = NULL;
 874     }
 875
 876     if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
 877         goto err;
 878
 879     penclen = CMS_SharedInfo_encode(&penc, wrap_alg, ukm, keylen);
 880
 881     if (!penclen)
 882         goto err;
 883
 884     if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, penc, penclen) <= 0)
 885         goto err;
 886     penc = NULL;
 887
 888     /*
 889      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
 890      * of another AlgorithmIdentifier.
 891      */
 892     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 893     if (!penc || !penclen)
 894         goto err;
 895     wrap_str = ASN1_STRING_new();
 896     if (wrap_str == NULL)
 897         goto err;
 898     ASN1_STRING_set0(wrap_str, penc, penclen);
 899     penc = NULL;
 900     X509_ALGOR_set0(talg, OBJ_nid2obj(kdf_nid), V_ASN1_SEQUENCE, wrap_str);
 901
 902     rv = 1;
 903
 904  err:
 905     OPENSSL_free(penc);
 906     X509_ALGOR_free(wrap_alg);
 907     return rv;
 908 }
 909
 910 #endif