crypto/ec/ec_ameth.c

   1 /*
   2  * Copyright 2006-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdio.h>
  11 #include "internal/cryptlib.h"
  12 #include <openssl/x509.h>
  13 #include <openssl/ec.h>
  14 #include <openssl/bn.h>
  15 #include <openssl/cms.h>
  16 #include <openssl/asn1t.h>
  17 #include "crypto/asn1.h"
  18 #include "crypto/evp.h"
  19 #include "ec_local.h"
  20
  21 #ifndef OPENSSL_NO_CMS
  22 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri);
  23 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri);
  24 #endif
  25
  26 static int eckey_param2type(int *pptype, void **ppval, EC_KEY *ec_key)
  27 {
  28     const EC_GROUP *group;
  29     int nid;
  30     if (ec_key == NULL || (group = EC_KEY_get0_group(ec_key)) == NULL) {
  31         ECerr(EC_F_ECKEY_PARAM2TYPE, EC_R_MISSING_PARAMETERS);
  32         return 0;
  33     }
  34     if (EC_GROUP_get_asn1_flag(group)
  35         && (nid = EC_GROUP_get_curve_name(group)))
  36         /* we have a 'named curve' => just set the OID */
  37     {
  38         *ppval = OBJ_nid2obj(nid);
  39         *pptype = V_ASN1_OBJECT;
  40     } else {                    /* explicit parameters */
  41
  42         ASN1_STRING *pstr = NULL;
  43         pstr = ASN1_STRING_new();
  44         if (pstr == NULL)
  45             return 0;
  46         pstr->length = i2d_ECParameters(ec_key, &pstr->data);
  47         if (pstr->length <= 0) {
  48             ASN1_STRING_free(pstr);
  49             ECerr(EC_F_ECKEY_PARAM2TYPE, ERR_R_EC_LIB);
  50             return 0;
  51         }
  52         *ppval = pstr;
  53         *pptype = V_ASN1_SEQUENCE;
  54     }
  55     return 1;
  56 }
  57
  58 static int eckey_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
  59 {
  60     EC_KEY *ec_key = pkey->pkey.ec;
  61     void *pval = NULL;
  62     int ptype;
  63     unsigned char *penc = NULL, *p;
  64     int penclen;
  65
  66     if (!eckey_param2type(&ptype, &pval, ec_key)) {
  67         ECerr(EC_F_ECKEY_PUB_ENCODE, ERR_R_EC_LIB);
  68         return 0;
  69     }
  70     penclen = i2o_ECPublicKey(ec_key, NULL);
  71     if (penclen <= 0)
  72         goto err;
  73     penc = OPENSSL_malloc(penclen);
  74     if (penc == NULL)
  75         goto err;
  76     p = penc;
  77     penclen = i2o_ECPublicKey(ec_key, &p);
  78     if (penclen <= 0)
  79         goto err;
  80     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(EVP_PKEY_EC),
  81                                ptype, pval, penc, penclen))
  82         return 1;
  83  err:
  84     if (ptype == V_ASN1_OBJECT)
  85         ASN1_OBJECT_free(pval);
  86     else
  87         ASN1_STRING_free(pval);
  88     OPENSSL_free(penc);
  89     return 0;
  90 }
  91
  92 static EC_KEY *eckey_type2param(int ptype, const void *pval)
  93 {
  94     EC_KEY *eckey = NULL;
  95     EC_GROUP *group = NULL;
  96
  97     if (ptype == V_ASN1_SEQUENCE) {
  98         const ASN1_STRING *pstr = pval;
  99         const unsigned char *pm = pstr->data;
 100         int pmlen = pstr->length;
 101
 102         if ((eckey = d2i_ECParameters(NULL, &pm, pmlen)) == NULL) {
 103             ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
 104             goto ecerr;
 105         }
 106     } else if (ptype == V_ASN1_OBJECT) {
 107         const ASN1_OBJECT *poid = pval;
 108
 109         /*
 110          * type == V_ASN1_OBJECT => the parameters are given by an asn1 OID
 111          */
 112         if ((eckey = EC_KEY_new()) == NULL) {
 113             ECerr(EC_F_ECKEY_TYPE2PARAM, ERR_R_MALLOC_FAILURE);
 114             goto ecerr;
 115         }
 116         group = EC_GROUP_new_by_curve_name(OBJ_obj2nid(poid));
 117         if (group == NULL)
 118             goto ecerr;
 119         EC_GROUP_set_asn1_flag(group, OPENSSL_EC_NAMED_CURVE);
 120         if (EC_KEY_set_group(eckey, group) == 0)
 121             goto ecerr;
 122         EC_GROUP_free(group);
 123     } else {
 124         ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
 125         goto ecerr;
 126     }
 127
 128     return eckey;
 129
 130  ecerr:
 131     EC_KEY_free(eckey);
 132     EC_GROUP_free(group);
 133     return NULL;
 134 }
 135
 136 static int eckey_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
 137 {
 138     const unsigned char *p = NULL;
 139     const void *pval;
 140     int ptype, pklen;
 141     EC_KEY *eckey = NULL;
 142     X509_ALGOR *palg;
 143
 144     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
 145         return 0;
 146     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 147
 148     eckey = eckey_type2param(ptype, pval);
 149
 150     if (!eckey) {
 151         ECerr(EC_F_ECKEY_PUB_DECODE, ERR_R_EC_LIB);
 152         return 0;
 153     }
 154
 155     /* We have parameters now set public key */
 156     if (!o2i_ECPublicKey(&eckey, &p, pklen)) {
 157         ECerr(EC_F_ECKEY_PUB_DECODE, EC_R_DECODE_ERROR);
 158         goto ecerr;
 159     }
 160
 161     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 162     return 1;
 163
 164  ecerr:
 165     EC_KEY_free(eckey);
 166     return 0;
 167 }
 168
 169 static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 170 {
 171     int r;
 172     const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec);
 173     const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec),
 174         *pb = EC_KEY_get0_public_key(b->pkey.ec);
 175     if (group == NULL || pa == NULL || pb == NULL)
 176         return -2;
 177     r = EC_POINT_cmp(group, pa, pb, NULL);
 178     if (r == 0)
 179         return 1;
 180     if (r == 1)
 181         return 0;
 182     return -2;
 183 }
 184
 185 static int eckey_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
 186 {
 187     const unsigned char *p = NULL;
 188     const void *pval;
 189     int ptype, pklen;
 190     EC_KEY *eckey = NULL;
 191     const X509_ALGOR *palg;
 192
 193     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 194         return 0;
 195     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 196
 197     eckey = eckey_type2param(ptype, pval);
 198
 199     if (!eckey)
 200         goto ecliberr;
 201
 202     /* We have parameters now set private key */
 203     if (!d2i_ECPrivateKey(&eckey, &p, pklen)) {
 204         ECerr(EC_F_ECKEY_PRIV_DECODE, EC_R_DECODE_ERROR);
 205         goto ecerr;
 206     }
 207
 208     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 209     return 1;
 210
 211  ecliberr:
 212     ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
 213  ecerr:
 214     EC_KEY_free(eckey);
 215     return 0;
 216 }
 217
 218 static int eckey_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 219 {
 220     EC_KEY ec_key = *(pkey->pkey.ec);
 221     unsigned char *ep, *p;
 222     int eplen, ptype;
 223     void *pval;
 224     unsigned int old_flags;
 225
 226     if (!eckey_param2type(&ptype, &pval, &ec_key)) {
 227         ECerr(EC_F_ECKEY_PRIV_ENCODE, EC_R_DECODE_ERROR);
 228         return 0;
 229     }
 230
 231     /* set the private key */
 232
 233     /*
 234      * do not include the parameters in the SEC1 private key see PKCS#11
 235      * 12.11
 236      */
 237     old_flags = EC_KEY_get_enc_flags(&ec_key);
 238     EC_KEY_set_enc_flags(&ec_key, old_flags | EC_PKEY_NO_PARAMETERS);
 239
 240     eplen = i2d_ECPrivateKey(&ec_key, NULL);
 241     if (!eplen) {
 242         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
 243         return 0;
 244     }
 245     ep = OPENSSL_malloc(eplen);
 246     if (ep == NULL) {
 247         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 248         return 0;
 249     }
 250     p = ep;
 251     if (!i2d_ECPrivateKey(&ec_key, &p)) {
 252         OPENSSL_free(ep);
 253         ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
 254         return 0;
 255     }
 256
 257     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0,
 258                          ptype, pval, ep, eplen)) {
 259         OPENSSL_free(ep);
 260         return 0;
 261     }
 262
 263     return 1;
 264 }
 265
 266 static int int_ec_size(const EVP_PKEY *pkey)
 267 {
 268     return ECDSA_size(pkey->pkey.ec);
 269 }
 270
 271 static int ec_bits(const EVP_PKEY *pkey)
 272 {
 273     return EC_GROUP_order_bits(EC_KEY_get0_group(pkey->pkey.ec));
 274 }
 275
 276 static int ec_security_bits(const EVP_PKEY *pkey)
 277 {
 278     int ecbits = ec_bits(pkey);
 279     if (ecbits >= 512)
 280         return 256;
 281     if (ecbits >= 384)
 282         return 192;
 283     if (ecbits >= 256)
 284         return 128;
 285     if (ecbits >= 224)
 286         return 112;
 287     if (ecbits >= 160)
 288         return 80;
 289     return ecbits / 2;
 290 }
 291
 292 static int ec_missing_parameters(const EVP_PKEY *pkey)
 293 {
 294     if (pkey->pkey.ec == NULL || EC_KEY_get0_group(pkey->pkey.ec) == NULL)
 295         return 1;
 296     return 0;
 297 }
 298
 299 static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 300 {
 301     EC_GROUP *group = EC_GROUP_dup(EC_KEY_get0_group(from->pkey.ec));
 302
 303     if (group == NULL)
 304         return 0;
 305     if (to->pkey.ec == NULL) {
 306         to->pkey.ec = EC_KEY_new();
 307         if (to->pkey.ec == NULL)
 308             goto err;
 309     }
 310     if (EC_KEY_set_group(to->pkey.ec, group) == 0)
 311         goto err;
 312     EC_GROUP_free(group);
 313     return 1;
 314  err:
 315     EC_GROUP_free(group);
 316     return 0;
 317 }
 318
 319 static int ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 320 {
 321     const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec),
 322         *group_b = EC_KEY_get0_group(b->pkey.ec);
 323     if (group_a == NULL || group_b == NULL)
 324         return -2;
 325     if (EC_GROUP_cmp(group_a, group_b, NULL))
 326         return 0;
 327     else
 328         return 1;
 329 }
 330
 331 static void int_ec_free(EVP_PKEY *pkey)
 332 {
 333     EC_KEY_free(pkey->pkey.ec);
 334 }
 335
 336 typedef enum {
 337     EC_KEY_PRINT_PRIVATE,
 338     EC_KEY_PRINT_PUBLIC,
 339     EC_KEY_PRINT_PARAM
 340 } ec_print_t;
 341
 342 static int do_EC_KEY_print(BIO *bp, const EC_KEY *x, int off, ec_print_t ktype)
 343 {
 344     const char *ecstr;
 345     unsigned char *priv = NULL, *pub = NULL;
 346     size_t privlen = 0, publen = 0;
 347     int ret = 0;
 348     const EC_GROUP *group;
 349
 350     if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL) {
 351         ECerr(EC_F_DO_EC_KEY_PRINT, ERR_R_PASSED_NULL_PARAMETER);
 352         return 0;
 353     }
 354
 355     if (ktype != EC_KEY_PRINT_PARAM && EC_KEY_get0_public_key(x) != NULL) {
 356         publen = EC_KEY_key2buf(x, EC_KEY_get_conv_form(x), &pub, NULL);
 357         if (publen == 0)
 358             goto err;
 359     }
 360
 361     if (ktype == EC_KEY_PRINT_PRIVATE && EC_KEY_get0_private_key(x) != NULL) {
 362         privlen = EC_KEY_priv2buf(x, &priv);
 363         if (privlen == 0)
 364             goto err;
 365     }
 366
 367     if (ktype == EC_KEY_PRINT_PRIVATE)
 368         ecstr = "Private-Key";
 369     else if (ktype == EC_KEY_PRINT_PUBLIC)
 370         ecstr = "Public-Key";
 371     else
 372         ecstr = "ECDSA-Parameters";
 373
 374     if (!BIO_indent(bp, off, 128))
 375         goto err;
 376     if (BIO_printf(bp, "%s: (%d bit)\n", ecstr,
 377                    EC_GROUP_order_bits(group)) <= 0)
 378         goto err;
 379
 380     if (privlen != 0) {
 381         if (BIO_printf(bp, "%*spriv:\n", off, "") <= 0)
 382             goto err;
 383         if (ASN1_buf_print(bp, priv, privlen, off + 4) == 0)
 384             goto err;
 385     }
 386
 387     if (publen != 0) {
 388         if (BIO_printf(bp, "%*spub:\n", off, "") <= 0)
 389             goto err;
 390         if (ASN1_buf_print(bp, pub, publen, off + 4) == 0)
 391             goto err;
 392     }
 393
 394     if (!ECPKParameters_print(bp, group, off))
 395         goto err;
 396     ret = 1;
 397  err:
 398     if (!ret)
 399         ECerr(EC_F_DO_EC_KEY_PRINT, ERR_R_EC_LIB);
 400     OPENSSL_clear_free(priv, privlen);
 401     OPENSSL_free(pub);
 402     return ret;
 403 }
 404
 405 static int eckey_param_decode(EVP_PKEY *pkey,
 406                               const unsigned char **pder, int derlen)
 407 {
 408     EC_KEY *eckey;
 409
 410     if ((eckey = d2i_ECParameters(NULL, pder, derlen)) == NULL) {
 411         ECerr(EC_F_ECKEY_PARAM_DECODE, ERR_R_EC_LIB);
 412         return 0;
 413     }
 414     EVP_PKEY_assign_EC_KEY(pkey, eckey);
 415     return 1;
 416 }
 417
 418 static int eckey_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 419 {
 420     return i2d_ECParameters(pkey->pkey.ec, pder);
 421 }
 422
 423 static int eckey_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 424                              ASN1_PCTX *ctx)
 425 {
 426     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PARAM);
 427 }
 428
 429 static int eckey_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 430                            ASN1_PCTX *ctx)
 431 {
 432     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PUBLIC);
 433 }
 434
 435 static int eckey_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 436                             ASN1_PCTX *ctx)
 437 {
 438     return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PRIVATE);
 439 }
 440
 441 static int old_ec_priv_decode(EVP_PKEY *pkey,
 442                               const unsigned char **pder, int derlen)
 443 {
 444     EC_KEY *ec;
 445
 446     if ((ec = d2i_ECPrivateKey(NULL, pder, derlen)) == NULL) {
 447         ECerr(EC_F_OLD_EC_PRIV_DECODE, EC_R_DECODE_ERROR);
 448         return 0;
 449     }
 450     EVP_PKEY_assign_EC_KEY(pkey, ec);
 451     return 1;
 452 }
 453
 454 static int old_ec_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
 455 {
 456     return i2d_ECPrivateKey(pkey->pkey.ec, pder);
 457 }
 458
 459 static int ec_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 460 {
 461     switch (op) {
 462     case ASN1_PKEY_CTRL_PKCS7_SIGN:
 463         if (arg1 == 0) {
 464             int snid, hnid;
 465             X509_ALGOR *alg1, *alg2;
 466             PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2);
 467             if (alg1 == NULL || alg1->algorithm == NULL)
 468                 return -1;
 469             hnid = OBJ_obj2nid(alg1->algorithm);
 470             if (hnid == NID_undef)
 471                 return -1;
 472             if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 473                 return -1;
 474             X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 475         }
 476         return 1;
 477 #ifndef OPENSSL_NO_CMS
 478     case ASN1_PKEY_CTRL_CMS_SIGN:
 479         if (arg1 == 0) {
 480             int snid, hnid;
 481             X509_ALGOR *alg1, *alg2;
 482             CMS_SignerInfo_get0_algs(arg2, NULL, NULL, &alg1, &alg2);
 483             if (alg1 == NULL || alg1->algorithm == NULL)
 484                 return -1;
 485             hnid = OBJ_obj2nid(alg1->algorithm);
 486             if (hnid == NID_undef)
 487                 return -1;
 488             if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
 489                 return -1;
 490             X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
 491         }
 492         return 1;
 493
 494     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 495         if (arg1 == 1)
 496             return ecdh_cms_decrypt(arg2);
 497         else if (arg1 == 0)
 498             return ecdh_cms_encrypt(arg2);
 499         return -2;
 500
 501     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 502         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 503         return 1;
 504 #endif
 505
 506     case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
 507         if (EVP_PKEY_id(pkey) == EVP_PKEY_SM2) {
 508             /* For SM2, the only valid digest-alg is SM3 */
 509             *(int *)arg2 = NID_sm3;
 510         } else {
 511             *(int *)arg2 = NID_sha256;
 512         }
 513         return 1;
 514
 515     case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
 516         return EC_KEY_oct2key(EVP_PKEY_get0_EC_KEY(pkey), arg2, arg1, NULL);
 517
 518     case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
 519         return EC_KEY_key2buf(EVP_PKEY_get0_EC_KEY(pkey),
 520                               POINT_CONVERSION_UNCOMPRESSED, arg2, NULL);
 521
 522     default:
 523         return -2;
 524
 525     }
 526
 527 }
 528
 529 static int ec_pkey_check(const EVP_PKEY *pkey)
 530 {
 531     EC_KEY *eckey = pkey->pkey.ec;
 532
 533     /* stay consistent to what EVP_PKEY_check demands */
 534     if (eckey->priv_key == NULL) {
 535         ECerr(EC_F_EC_PKEY_CHECK, EC_R_MISSING_PRIVATE_KEY);
 536         return 0;
 537     }
 538
 539     return EC_KEY_check_key(eckey);
 540 }
 541
 542 static int ec_pkey_public_check(const EVP_PKEY *pkey)
 543 {
 544     EC_KEY *eckey = pkey->pkey.ec;
 545
 546     /*
 547      * Note: it unnecessary to check eckey->pub_key here since
 548      * it will be checked in EC_KEY_check_key(). In fact, the
 549      * EC_KEY_check_key() mainly checks the public key, and checks
 550      * the private key optionally (only if there is one). So if
 551      * someone passes a whole EC key (public + private), this
 552      * will also work...
 553      */
 554
 555     return EC_KEY_check_key(eckey);
 556 }
 557
 558 static int ec_pkey_param_check(const EVP_PKEY *pkey)
 559 {
 560     EC_KEY *eckey = pkey->pkey.ec;
 561
 562     /* stay consistent to what EVP_PKEY_check demands */
 563     if (eckey->group == NULL) {
 564         ECerr(EC_F_EC_PKEY_PARAM_CHECK, EC_R_MISSING_PARAMETERS);
 565         return 0;
 566     }
 567
 568     return EC_GROUP_check(eckey->group, NULL);
 569 }
 570
 571 const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = {
 572     EVP_PKEY_EC,
 573     EVP_PKEY_EC,
 574     0,
 575     "EC",
 576     "OpenSSL EC algorithm",
 577
 578     eckey_pub_decode,
 579     eckey_pub_encode,
 580     eckey_pub_cmp,
 581     eckey_pub_print,
 582
 583     eckey_priv_decode,
 584     eckey_priv_encode,
 585     eckey_priv_print,
 586
 587     int_ec_size,
 588     ec_bits,
 589     ec_security_bits,
 590
 591     eckey_param_decode,
 592     eckey_param_encode,
 593     ec_missing_parameters,
 594     ec_copy_parameters,
 595     ec_cmp_parameters,
 596     eckey_param_print,
 597     0,
 598
 599     int_ec_free,
 600     ec_pkey_ctrl,
 601     old_ec_priv_decode,
 602     old_ec_priv_encode,
 603
 604     0, 0, 0,
 605
 606     ec_pkey_check,
 607     ec_pkey_public_check,
 608     ec_pkey_param_check
 609 };
 610
 611 #if !defined(OPENSSL_NO_SM2)
 612 const EVP_PKEY_ASN1_METHOD sm2_asn1_meth = {
 613    EVP_PKEY_SM2,
 614    EVP_PKEY_EC,
 615    ASN1_PKEY_ALIAS
 616 };
 617 #endif
 618
 619 int EC_KEY_print(BIO *bp, const EC_KEY *x, int off)
 620 {
 621     int private = EC_KEY_get0_private_key(x) != NULL;
 622
 623     return do_EC_KEY_print(bp, x, off,
 624                 private ? EC_KEY_PRINT_PRIVATE : EC_KEY_PRINT_PUBLIC);
 625 }
 626
 627 int ECParameters_print(BIO *bp, const EC_KEY *x)
 628 {
 629     return do_EC_KEY_print(bp, x, 4, EC_KEY_PRINT_PARAM);
 630 }
 631
 632 #ifndef OPENSSL_NO_CMS
 633
 634 static int ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 635                                 X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 636 {
 637     const ASN1_OBJECT *aoid;
 638     int atype;
 639     const void *aval;
 640     int rv = 0;
 641     EVP_PKEY *pkpeer = NULL;
 642     EC_KEY *ecpeer = NULL;
 643     const unsigned char *p;
 644     int plen;
 645     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 646     if (OBJ_obj2nid(aoid) != NID_X9_62_id_ecPublicKey)
 647         goto err;
 648     /* If absent parameters get group from main key */
 649     if (atype == V_ASN1_UNDEF || atype == V_ASN1_NULL) {
 650         const EC_GROUP *grp;
 651         EVP_PKEY *pk;
 652         pk = EVP_PKEY_CTX_get0_pkey(pctx);
 653         if (!pk)
 654             goto err;
 655         grp = EC_KEY_get0_group(pk->pkey.ec);
 656         ecpeer = EC_KEY_new();
 657         if (ecpeer == NULL)
 658             goto err;
 659         if (!EC_KEY_set_group(ecpeer, grp))
 660             goto err;
 661     } else {
 662         ecpeer = eckey_type2param(atype, aval);
 663         if (!ecpeer)
 664             goto err;
 665     }
 666     /* We have parameters now set public key */
 667     plen = ASN1_STRING_length(pubkey);
 668     p = ASN1_STRING_get0_data(pubkey);
 669     if (!p || !plen)
 670         goto err;
 671     if (!o2i_ECPublicKey(&ecpeer, &p, plen))
 672         goto err;
 673     pkpeer = EVP_PKEY_new();
 674     if (pkpeer == NULL)
 675         goto err;
 676     EVP_PKEY_set1_EC_KEY(pkpeer, ecpeer);
 677     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 678         rv = 1;
 679  err:
 680     EC_KEY_free(ecpeer);
 681     EVP_PKEY_free(pkpeer);
 682     return rv;
 683 }
 684
 685 /* Set KDF parameters based on KDF NID */
 686 static int ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid)
 687 {
 688     int kdf_nid, kdfmd_nid, cofactor;
 689     const EVP_MD *kdf_md;
 690     if (eckdf_nid == NID_undef)
 691         return 0;
 692
 693     /* Lookup KDF type, cofactor mode and digest */
 694     if (!OBJ_find_sigid_algs(eckdf_nid, &kdfmd_nid, &kdf_nid))
 695         return 0;
 696
 697     if (kdf_nid == NID_dh_std_kdf)
 698         cofactor = 0;
 699     else if (kdf_nid == NID_dh_cofactor_kdf)
 700         cofactor = 1;
 701     else
 702         return 0;
 703
 704     if (EVP_PKEY_CTX_set_ecdh_cofactor_mode(pctx, cofactor) <= 0)
 705         return 0;
 706
 707     if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, EVP_PKEY_ECDH_KDF_X9_63) <= 0)
 708         return 0;
 709
 710     kdf_md = EVP_get_digestbynid(kdfmd_nid);
 711     if (!kdf_md)
 712         return 0;
 713
 714     if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
 715         return 0;
 716     return 1;
 717 }
 718
 719 static int ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 720 {
 721     int rv = 0;
 722
 723     X509_ALGOR *alg, *kekalg = NULL;
 724     ASN1_OCTET_STRING *ukm;
 725     const unsigned char *p;
 726     unsigned char *der = NULL;
 727     int plen, keylen;
 728     const EVP_CIPHER *kekcipher;
 729     EVP_CIPHER_CTX *kekctx;
 730
 731     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 732         return 0;
 733
 734     if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) {
 735         ECerr(EC_F_ECDH_CMS_SET_SHARED_INFO, EC_R_KDF_PARAMETER_ERROR);
 736         return 0;
 737     }
 738
 739     if (alg->parameter->type != V_ASN1_SEQUENCE)
 740         return 0;
 741
 742     p = alg->parameter->value.sequence->data;
 743     plen = alg->parameter->value.sequence->length;
 744     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 745     if (!kekalg)
 746         goto err;
 747     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 748     if (!kekctx)
 749         goto err;
 750     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 751     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 752         goto err;
 753     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 754         goto err;
 755     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 756         goto err;
 757
 758     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 759     if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
 760         goto err;
 761
 762     plen = CMS_SharedInfo_encode(&der, kekalg, ukm, keylen);
 763
 764     if (!plen)
 765         goto err;
 766
 767     if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
 768         goto err;
 769     der = NULL;
 770
 771     rv = 1;
 772  err:
 773     X509_ALGOR_free(kekalg);
 774     OPENSSL_free(der);
 775     return rv;
 776 }
 777
 778 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri)
 779 {
 780     EVP_PKEY_CTX *pctx;
 781     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 782     if (!pctx)
 783         return 0;
 784     /* See if we need to set peer key */
 785     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 786         X509_ALGOR *alg;
 787         ASN1_BIT_STRING *pubkey;
 788         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 789                                                  NULL, NULL, NULL))
 790             return 0;
 791         if (!alg || !pubkey)
 792             return 0;
 793         if (!ecdh_cms_set_peerkey(pctx, alg, pubkey)) {
 794             ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_PEER_KEY_ERROR);
 795             return 0;
 796         }
 797     }
 798     /* Set ECDH derivation parameters and initialise unwrap context */
 799     if (!ecdh_cms_set_shared_info(pctx, ri)) {
 800         ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_SHARED_INFO_ERROR);
 801         return 0;
 802     }
 803     return 1;
 804 }
 805
 806 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri)
 807 {
 808     EVP_PKEY_CTX *pctx;
 809     EVP_PKEY *pkey;
 810     EVP_CIPHER_CTX *ctx;
 811     int keylen;
 812     X509_ALGOR *talg, *wrap_alg = NULL;
 813     const ASN1_OBJECT *aoid;
 814     ASN1_BIT_STRING *pubkey;
 815     ASN1_STRING *wrap_str;
 816     ASN1_OCTET_STRING *ukm;
 817     unsigned char *penc = NULL;
 818     int penclen;
 819     int rv = 0;
 820     int ecdh_nid, kdf_type, kdf_nid, wrap_nid;
 821     const EVP_MD *kdf_md;
 822     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 823     if (!pctx)
 824         return 0;
 825     /* Get ephemeral key */
 826     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 827     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 828                                              NULL, NULL, NULL))
 829         goto err;
 830     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 831     /* Is everything uninitialised? */
 832     if (aoid == OBJ_nid2obj(NID_undef)) {
 833
 834         EC_KEY *eckey = pkey->pkey.ec;
 835         /* Set the key */
 836         unsigned char *p;
 837
 838         penclen = i2o_ECPublicKey(eckey, NULL);
 839         if (penclen <= 0)
 840             goto err;
 841         penc = OPENSSL_malloc(penclen);
 842         if (penc == NULL)
 843             goto err;
 844         p = penc;
 845         penclen = i2o_ECPublicKey(eckey, &p);
 846         if (penclen <= 0)
 847             goto err;
 848         ASN1_STRING_set0(pubkey, penc, penclen);
 849         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 850         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 851
 852         penc = NULL;
 853         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_X9_62_id_ecPublicKey),
 854                         V_ASN1_UNDEF, NULL);
 855     }
 856
 857     /* See if custom parameters set */
 858     kdf_type = EVP_PKEY_CTX_get_ecdh_kdf_type(pctx);
 859     if (kdf_type <= 0)
 860         goto err;
 861     if (!EVP_PKEY_CTX_get_ecdh_kdf_md(pctx, &kdf_md))
 862         goto err;
 863     ecdh_nid = EVP_PKEY_CTX_get_ecdh_cofactor_mode(pctx);
 864     if (ecdh_nid < 0)
 865         goto err;
 866     else if (ecdh_nid == 0)
 867         ecdh_nid = NID_dh_std_kdf;
 868     else if (ecdh_nid == 1)
 869         ecdh_nid = NID_dh_cofactor_kdf;
 870
 871     if (kdf_type == EVP_PKEY_ECDH_KDF_NONE) {
 872         kdf_type = EVP_PKEY_ECDH_KDF_X9_63;
 873         if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0)
 874             goto err;
 875     } else
 876         /* Unknown KDF */
 877         goto err;
 878     if (kdf_md == NULL) {
 879         /* Fixme later for better MD */
 880         kdf_md = EVP_sha1();
 881         if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
 882             goto err;
 883     }
 884
 885     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 886         goto err;
 887
 888     /* Lookup NID for KDF+cofactor+digest */
 889
 890     if (!OBJ_find_sigid_by_algs(&kdf_nid, EVP_MD_type(kdf_md), ecdh_nid))
 891         goto err;
 892     /* Get wrap NID */
 893     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 894     wrap_nid = EVP_CIPHER_CTX_type(ctx);
 895     keylen = EVP_CIPHER_CTX_key_length(ctx);
 896
 897     /* Package wrap algorithm in an AlgorithmIdentifier */
 898
 899     wrap_alg = X509_ALGOR_new();
 900     if (wrap_alg == NULL)
 901         goto err;
 902     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 903     wrap_alg->parameter = ASN1_TYPE_new();
 904     if (wrap_alg->parameter == NULL)
 905         goto err;
 906     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 907         goto err;
 908     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
 909         ASN1_TYPE_free(wrap_alg->parameter);
 910         wrap_alg->parameter = NULL;
 911     }
 912
 913     if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
 914         goto err;
 915
 916     penclen = CMS_SharedInfo_encode(&penc, wrap_alg, ukm, keylen);
 917
 918     if (!penclen)
 919         goto err;
 920
 921     if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, penc, penclen) <= 0)
 922         goto err;
 923     penc = NULL;
 924
 925     /*
 926      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
 927      * of another AlgorithmIdentifier.
 928      */
 929     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 930     if (!penc || !penclen)
 931         goto err;
 932     wrap_str = ASN1_STRING_new();
 933     if (wrap_str == NULL)
 934         goto err;
 935     ASN1_STRING_set0(wrap_str, penc, penclen);
 936     penc = NULL;
 937     X509_ALGOR_set0(talg, OBJ_nid2obj(kdf_nid), V_ASN1_SEQUENCE, wrap_str);
 938
 939     rv = 1;
 940
 941  err:
 942     OPENSSL_free(penc);
 943     X509_ALGOR_free(wrap_alg);
 944     return rv;
 945 }
 946
 947 #endif