2 * Copyright 2006-2020 The OpenSSL Project Authors. All Rights Reserved.
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
11 * ECDH and ECDSA low level APIs are deprecated for public use, but still ok
14 #include "internal/deprecated.h"
17 #include "internal/cryptlib.h"
18 #include <openssl/x509.h>
19 #include <openssl/ec.h>
20 #include <openssl/bn.h>
21 #include <openssl/cms.h>
22 #include <openssl/asn1t.h>
23 #include "crypto/asn1.h"
24 #include "crypto/evp.h"
25 #include <openssl/core_names.h>
26 #include "openssl/param_build.h"
29 #ifndef OPENSSL_NO_CMS
30 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri);
31 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri);
34 static int eckey_param2type(int *pptype, void **ppval, const EC_KEY *ec_key)
36 const EC_GROUP *group;
38 if (ec_key == NULL || (group = EC_KEY_get0_group(ec_key)) == NULL) {
39 ECerr(EC_F_ECKEY_PARAM2TYPE, EC_R_MISSING_PARAMETERS);
42 if (EC_GROUP_get_asn1_flag(group)
43 && (nid = EC_GROUP_get_curve_name(group)))
44 /* we have a 'named curve' => just set the OID */
46 *ppval = OBJ_nid2obj(nid);
47 *pptype = V_ASN1_OBJECT;
48 } else { /* explicit parameters */
50 ASN1_STRING *pstr = NULL;
51 pstr = ASN1_STRING_new();
54 pstr->length = i2d_ECParameters(ec_key, &pstr->data);
55 if (pstr->length <= 0) {
56 ASN1_STRING_free(pstr);
57 ECerr(EC_F_ECKEY_PARAM2TYPE, ERR_R_EC_LIB);
61 *pptype = V_ASN1_SEQUENCE;
66 static int eckey_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
68 const EC_KEY *ec_key = pkey->pkey.ec;
71 unsigned char *penc = NULL, *p;
74 if (!eckey_param2type(&ptype, &pval, ec_key)) {
75 ECerr(EC_F_ECKEY_PUB_ENCODE, ERR_R_EC_LIB);
78 penclen = i2o_ECPublicKey(ec_key, NULL);
81 penc = OPENSSL_malloc(penclen);
85 penclen = i2o_ECPublicKey(ec_key, &p);
88 if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(EVP_PKEY_EC),
89 ptype, pval, penc, penclen))
92 if (ptype == V_ASN1_OBJECT)
93 ASN1_OBJECT_free(pval);
95 ASN1_STRING_free(pval);
100 static EC_KEY *eckey_type2param(int ptype, const void *pval,
101 OPENSSL_CTX *libctx, const char *propq)
103 EC_KEY *eckey = NULL;
104 EC_GROUP *group = NULL;
106 if ((eckey = EC_KEY_new_with_libctx(libctx, propq)) == NULL) {
107 ECerr(EC_F_ECKEY_TYPE2PARAM, ERR_R_MALLOC_FAILURE);
111 if (ptype == V_ASN1_SEQUENCE) {
112 const ASN1_STRING *pstr = pval;
113 const unsigned char *pm = pstr->data;
114 int pmlen = pstr->length;
117 if (d2i_ECParameters(&eckey, &pm, pmlen) == NULL) {
118 ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
121 } else if (ptype == V_ASN1_OBJECT) {
122 const ASN1_OBJECT *poid = pval;
125 * type == V_ASN1_OBJECT => the parameters are given by an asn1 OID
128 group = EC_GROUP_new_by_curve_name_with_libctx(libctx, propq,
132 EC_GROUP_set_asn1_flag(group, OPENSSL_EC_NAMED_CURVE);
133 if (EC_KEY_set_group(eckey, group) == 0)
135 EC_GROUP_free(group);
137 ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
145 EC_GROUP_free(group);
149 static int eckey_pub_decode(EVP_PKEY *pkey, const X509_PUBKEY *pubkey)
151 const unsigned char *p = NULL;
154 EC_KEY *eckey = NULL;
157 if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
159 X509_ALGOR_get0(NULL, &ptype, &pval, palg);
161 eckey = eckey_type2param(ptype, pval, NULL, NULL);
164 ECerr(EC_F_ECKEY_PUB_DECODE, ERR_R_EC_LIB);
168 /* We have parameters now set public key */
169 if (!o2i_ECPublicKey(&eckey, &p, pklen)) {
170 ECerr(EC_F_ECKEY_PUB_DECODE, EC_R_DECODE_ERROR);
174 EVP_PKEY_assign_EC_KEY(pkey, eckey);
182 static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
185 const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec);
186 const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec),
187 *pb = EC_KEY_get0_public_key(b->pkey.ec);
188 if (group == NULL || pa == NULL || pb == NULL)
190 r = EC_POINT_cmp(group, pa, pb, NULL);
198 static int eckey_priv_decode_with_libctx(EVP_PKEY *pkey,
199 const PKCS8_PRIV_KEY_INFO *p8,
203 const unsigned char *p = NULL;
206 EC_KEY *eckey = NULL;
207 const X509_ALGOR *palg;
209 if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
211 X509_ALGOR_get0(NULL, &ptype, &pval, palg);
213 eckey = eckey_type2param(ptype, pval, libctx, propq);
218 /* We have parameters now set private key */
219 if (!d2i_ECPrivateKey(&eckey, &p, pklen)) {
220 ECerr(0, EC_R_DECODE_ERROR);
224 EVP_PKEY_assign_EC_KEY(pkey, eckey);
228 ECerr(0, ERR_R_EC_LIB);
234 static int eckey_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
236 EC_KEY ec_key = *(pkey->pkey.ec);
237 unsigned char *ep, *p;
240 unsigned int old_flags;
242 if (!eckey_param2type(&ptype, &pval, &ec_key)) {
243 ECerr(EC_F_ECKEY_PRIV_ENCODE, EC_R_DECODE_ERROR);
247 /* set the private key */
250 * do not include the parameters in the SEC1 private key see PKCS#11
253 old_flags = EC_KEY_get_enc_flags(&ec_key);
254 EC_KEY_set_enc_flags(&ec_key, old_flags | EC_PKEY_NO_PARAMETERS);
256 eplen = i2d_ECPrivateKey(&ec_key, NULL);
258 ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
261 ep = OPENSSL_malloc(eplen);
263 ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
267 if (!i2d_ECPrivateKey(&ec_key, &p)) {
269 ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
273 if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0,
274 ptype, pval, ep, eplen)) {
282 static int int_ec_size(const EVP_PKEY *pkey)
284 return ECDSA_size(pkey->pkey.ec);
287 static int ec_bits(const EVP_PKEY *pkey)
289 return EC_GROUP_order_bits(EC_KEY_get0_group(pkey->pkey.ec));
292 static int ec_security_bits(const EVP_PKEY *pkey)
294 int ecbits = ec_bits(pkey);
308 static int ec_missing_parameters(const EVP_PKEY *pkey)
310 if (pkey->pkey.ec == NULL || EC_KEY_get0_group(pkey->pkey.ec) == NULL)
315 static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
317 EC_GROUP *group = EC_GROUP_dup(EC_KEY_get0_group(from->pkey.ec));
321 if (to->pkey.ec == NULL) {
322 to->pkey.ec = EC_KEY_new();
323 if (to->pkey.ec == NULL)
326 if (EC_KEY_set_group(to->pkey.ec, group) == 0)
328 EC_GROUP_free(group);
331 EC_GROUP_free(group);
335 static int ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
337 const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec),
338 *group_b = EC_KEY_get0_group(b->pkey.ec);
339 if (group_a == NULL || group_b == NULL)
341 if (EC_GROUP_cmp(group_a, group_b, NULL))
347 static void int_ec_free(EVP_PKEY *pkey)
349 EC_KEY_free(pkey->pkey.ec);
353 EC_KEY_PRINT_PRIVATE,
358 static int do_EC_KEY_print(BIO *bp, const EC_KEY *x, int off, ec_print_t ktype)
361 unsigned char *priv = NULL, *pub = NULL;
362 size_t privlen = 0, publen = 0;
364 const EC_GROUP *group;
366 if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL) {
367 ECerr(EC_F_DO_EC_KEY_PRINT, ERR_R_PASSED_NULL_PARAMETER);
371 if (ktype != EC_KEY_PRINT_PARAM && EC_KEY_get0_public_key(x) != NULL) {
372 publen = EC_KEY_key2buf(x, EC_KEY_get_conv_form(x), &pub, NULL);
377 if (ktype == EC_KEY_PRINT_PRIVATE && EC_KEY_get0_private_key(x) != NULL) {
378 privlen = EC_KEY_priv2buf(x, &priv);
383 if (ktype == EC_KEY_PRINT_PRIVATE)
384 ecstr = "Private-Key";
385 else if (ktype == EC_KEY_PRINT_PUBLIC)
386 ecstr = "Public-Key";
388 ecstr = "ECDSA-Parameters";
390 if (!BIO_indent(bp, off, 128))
392 if (BIO_printf(bp, "%s: (%d bit)\n", ecstr,
393 EC_GROUP_order_bits(group)) <= 0)
397 if (BIO_printf(bp, "%*spriv:\n", off, "") <= 0)
399 if (ASN1_buf_print(bp, priv, privlen, off + 4) == 0)
404 if (BIO_printf(bp, "%*spub:\n", off, "") <= 0)
406 if (ASN1_buf_print(bp, pub, publen, off + 4) == 0)
410 if (!ECPKParameters_print(bp, group, off))
415 ECerr(EC_F_DO_EC_KEY_PRINT, ERR_R_EC_LIB);
416 OPENSSL_clear_free(priv, privlen);
421 static int eckey_param_decode(EVP_PKEY *pkey,
422 const unsigned char **pder, int derlen)
426 if ((eckey = d2i_ECParameters(NULL, pder, derlen)) == NULL) {
427 ECerr(EC_F_ECKEY_PARAM_DECODE, ERR_R_EC_LIB);
430 EVP_PKEY_assign_EC_KEY(pkey, eckey);
434 static int eckey_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
436 return i2d_ECParameters(pkey->pkey.ec, pder);
439 static int eckey_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
442 return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PARAM);
445 static int eckey_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
448 return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PUBLIC);
451 static int eckey_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
454 return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PRIVATE);
457 static int old_ec_priv_decode(EVP_PKEY *pkey,
458 const unsigned char **pder, int derlen)
462 if ((ec = d2i_ECPrivateKey(NULL, pder, derlen)) == NULL) {
463 ECerr(EC_F_OLD_EC_PRIV_DECODE, EC_R_DECODE_ERROR);
466 EVP_PKEY_assign_EC_KEY(pkey, ec);
470 static int old_ec_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
472 return i2d_ECPrivateKey(pkey->pkey.ec, pder);
475 static int ec_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
478 case ASN1_PKEY_CTRL_PKCS7_SIGN:
481 X509_ALGOR *alg1, *alg2;
482 PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2);
483 if (alg1 == NULL || alg1->algorithm == NULL)
485 hnid = OBJ_obj2nid(alg1->algorithm);
486 if (hnid == NID_undef)
488 if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
490 X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
493 #ifndef OPENSSL_NO_CMS
494 case ASN1_PKEY_CTRL_CMS_SIGN:
497 X509_ALGOR *alg1, *alg2;
498 CMS_SignerInfo_get0_algs(arg2, NULL, NULL, &alg1, &alg2);
499 if (alg1 == NULL || alg1->algorithm == NULL)
501 hnid = OBJ_obj2nid(alg1->algorithm);
502 if (hnid == NID_undef)
504 if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
506 X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
510 case ASN1_PKEY_CTRL_CMS_ENVELOPE:
512 return ecdh_cms_decrypt(arg2);
514 return ecdh_cms_encrypt(arg2);
517 case ASN1_PKEY_CTRL_CMS_RI_TYPE:
518 *(int *)arg2 = CMS_RECIPINFO_AGREE;
522 case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
523 if (EVP_PKEY_id(pkey) == EVP_PKEY_SM2) {
524 /* For SM2, the only valid digest-alg is SM3 */
525 *(int *)arg2 = NID_sm3;
526 return 2; /* Make it mandatory */
528 *(int *)arg2 = NID_sha256;
531 case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
532 return EC_KEY_oct2key(EVP_PKEY_get0_EC_KEY(pkey), arg2, arg1, NULL);
534 case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
535 return EC_KEY_key2buf(EVP_PKEY_get0_EC_KEY(pkey),
536 POINT_CONVERSION_UNCOMPRESSED, arg2, NULL);
545 static int ec_pkey_check(const EVP_PKEY *pkey)
547 EC_KEY *eckey = pkey->pkey.ec;
549 /* stay consistent to what EVP_PKEY_check demands */
550 if (eckey->priv_key == NULL) {
551 ECerr(EC_F_EC_PKEY_CHECK, EC_R_MISSING_PRIVATE_KEY);
555 return EC_KEY_check_key(eckey);
558 static int ec_pkey_public_check(const EVP_PKEY *pkey)
560 EC_KEY *eckey = pkey->pkey.ec;
563 * Note: it unnecessary to check eckey->pub_key here since
564 * it will be checked in EC_KEY_check_key(). In fact, the
565 * EC_KEY_check_key() mainly checks the public key, and checks
566 * the private key optionally (only if there is one). So if
567 * someone passes a whole EC key (public + private), this
571 return EC_KEY_check_key(eckey);
574 static int ec_pkey_param_check(const EVP_PKEY *pkey)
576 EC_KEY *eckey = pkey->pkey.ec;
578 /* stay consistent to what EVP_PKEY_check demands */
579 if (eckey->group == NULL) {
580 ECerr(EC_F_EC_PKEY_PARAM_CHECK, EC_R_MISSING_PARAMETERS);
584 return EC_GROUP_check(eckey->group, NULL);
588 size_t ec_pkey_dirty_cnt(const EVP_PKEY *pkey)
590 return pkey->pkey.ec->dirty_cnt;
594 int ecparams_to_params(const EC_KEY *eckey, OSSL_PARAM_BLD *tmpl)
602 ecg = EC_KEY_get0_group(eckey);
606 curve_nid = EC_GROUP_get_curve_name(ecg);
608 if (curve_nid == NID_undef) {
609 /* explicit parameters */
612 * TODO(3.0): should we support explicit parameters curves?
617 const char *curve_name = NULL;
619 if ((curve_name = OBJ_nid2sn(curve_nid)) == NULL)
622 if (!OSSL_PARAM_BLD_push_utf8_string(tmpl, OSSL_PKEY_PARAM_GROUP_NAME, curve_name, 0))
630 int ec_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
631 EVP_KEYMGMT *to_keymgmt, OPENSSL_CTX *libctx,
634 const EC_KEY *eckey = NULL;
635 const EC_GROUP *ecg = NULL;
636 unsigned char *pub_key_buf = NULL;
637 size_t pub_key_buflen;
638 OSSL_PARAM_BLD *tmpl;
639 OSSL_PARAM *params = NULL;
640 const BIGNUM *priv_key = NULL;
641 const EC_POINT *pub_point = NULL;
644 BN_CTX *bnctx = NULL;
647 || (eckey = from->pkey.ec) == NULL
648 || (ecg = EC_KEY_get0_group(eckey)) == NULL)
652 * If the EC_KEY method is foreign, then we can't be sure of anything,
653 * and can therefore not export or pretend to export.
655 if (EC_KEY_get_method(eckey) != EC_KEY_OpenSSL())
658 tmpl = OSSL_PARAM_BLD_new();
662 /* export the domain parameters */
663 if (!ecparams_to_params(eckey, tmpl))
665 selection |= OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS;
667 priv_key = EC_KEY_get0_private_key(eckey);
668 pub_point = EC_KEY_get0_public_key(eckey);
670 if (pub_point != NULL) {
672 * EC_POINT_point2buf() can generate random numbers in some
673 * implementations so we need to ensure we use the correct libctx.
675 bnctx = BN_CTX_new_ex(libctx);
679 /* convert pub_point to a octet string according to the SECG standard */
680 if ((pub_key_buflen = EC_POINT_point2buf(ecg, pub_point,
681 POINT_CONVERSION_COMPRESSED,
682 &pub_key_buf, bnctx)) == 0
683 || !OSSL_PARAM_BLD_push_octet_string(tmpl,
684 OSSL_PKEY_PARAM_PUB_KEY,
688 selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
691 if (priv_key != NULL) {
694 int ecdh_cofactor_mode;
697 * Key import/export should never leak the bit length of the secret
700 * For this reason, on export we use padded BIGNUMs with fixed length.
702 * When importing we also should make sure that, even if short lived,
703 * the newly created BIGNUM is marked with the BN_FLG_CONSTTIME flag as
704 * soon as possible, so that any processing of this BIGNUM might opt for
705 * constant time implementations in the backend.
707 * Setting the BN_FLG_CONSTTIME flag alone is never enough, we also have
708 * to preallocate the BIGNUM internal buffer to a fixed public size big
709 * enough that operations performed during the processing never trigger
710 * a realloc which would leak the size of the scalar through memory
716 * The order of the large prime subgroup of the curve is our choice for
717 * a fixed public size, as that is generally the upper bound for
718 * generating a private key in EC cryptosystems and should fit all valid
721 * For padding on export we just use the bit length of the order
722 * converted to bytes (rounding up).
724 * For preallocating the BIGNUM storage we look at the number of "words"
725 * required for the internal representation of the order, and we
726 * preallocate 2 extra "words" in case any of the subsequent processing
727 * might temporarily overflow the order length.
729 ecbits = EC_GROUP_order_bits(ecg);
733 sz = (ecbits + 7 ) / 8;
734 if (!OSSL_PARAM_BLD_push_BN_pad(tmpl,
735 OSSL_PKEY_PARAM_PRIV_KEY,
738 selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
741 * The ECDH Cofactor Mode is defined only if the EC_KEY actually
742 * contains a private key, so we check for the flag and export it only
746 (EC_KEY_get_flags(eckey) & EC_FLAG_COFACTOR_ECDH) ? 1 : 0;
748 /* Export the ECDH_COFACTOR_MODE parameter */
749 if (!OSSL_PARAM_BLD_push_int(tmpl,
750 OSSL_PKEY_PARAM_USE_COFACTOR_ECDH,
753 selection |= OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS;
756 params = OSSL_PARAM_BLD_to_param(tmpl);
758 /* We export, the provider imports */
759 rv = evp_keymgmt_import(to_keymgmt, to_keydata, selection, params);
762 OSSL_PARAM_BLD_free(tmpl);
763 OSSL_PARAM_BLD_free_params(params);
764 OPENSSL_free(pub_key_buf);
769 static int ec_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
771 EVP_PKEY_CTX *pctx = vpctx;
772 EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
773 EC_KEY *ec = EC_KEY_new_with_libctx(pctx->libctx, pctx->propquery);
776 ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
780 if (!ec_key_domparams_fromdata(ec, params)
781 || !ec_key_otherparams_fromdata(ec, params)
782 || !ec_key_fromdata(ec, params, 1)
783 || !EVP_PKEY_assign_EC_KEY(pkey, ec)) {
790 const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = {
795 "OpenSSL EC algorithm",
812 ec_missing_parameters,
826 ec_pkey_public_check,
829 0, /* set_priv_key */
831 0, /* get_priv_key */
837 eckey_priv_decode_with_libctx
840 #if !defined(OPENSSL_NO_SM2)
841 const EVP_PKEY_ASN1_METHOD sm2_asn1_meth = {
848 int EC_KEY_print(BIO *bp, const EC_KEY *x, int off)
850 int private = EC_KEY_get0_private_key(x) != NULL;
852 return do_EC_KEY_print(bp, x, off,
853 private ? EC_KEY_PRINT_PRIVATE : EC_KEY_PRINT_PUBLIC);
856 int ECParameters_print(BIO *bp, const EC_KEY *x)
858 return do_EC_KEY_print(bp, x, 4, EC_KEY_PRINT_PARAM);
861 #ifndef OPENSSL_NO_CMS
863 static int ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
864 X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
866 const ASN1_OBJECT *aoid;
870 EVP_PKEY *pkpeer = NULL;
871 EC_KEY *ecpeer = NULL;
872 const unsigned char *p;
874 X509_ALGOR_get0(&aoid, &atype, &aval, alg);
875 if (OBJ_obj2nid(aoid) != NID_X9_62_id_ecPublicKey)
877 /* If absent parameters get group from main key */
878 if (atype == V_ASN1_UNDEF || atype == V_ASN1_NULL) {
881 pk = EVP_PKEY_CTX_get0_pkey(pctx);
884 grp = EC_KEY_get0_group(pk->pkey.ec);
885 ecpeer = EC_KEY_new();
888 if (!EC_KEY_set_group(ecpeer, grp))
891 ecpeer = eckey_type2param(atype, aval, pctx->libctx, pctx->propquery);
895 /* We have parameters now set public key */
896 plen = ASN1_STRING_length(pubkey);
897 p = ASN1_STRING_get0_data(pubkey);
898 if (p == NULL || plen == 0)
900 if (!o2i_ECPublicKey(&ecpeer, &p, plen))
902 pkpeer = EVP_PKEY_new();
905 EVP_PKEY_set1_EC_KEY(pkpeer, ecpeer);
906 if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
910 EVP_PKEY_free(pkpeer);
914 /* Set KDF parameters based on KDF NID */
915 static int ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid)
917 int kdf_nid, kdfmd_nid, cofactor;
918 const EVP_MD *kdf_md;
919 if (eckdf_nid == NID_undef)
922 /* Lookup KDF type, cofactor mode and digest */
923 if (!OBJ_find_sigid_algs(eckdf_nid, &kdfmd_nid, &kdf_nid))
926 if (kdf_nid == NID_dh_std_kdf)
928 else if (kdf_nid == NID_dh_cofactor_kdf)
933 if (EVP_PKEY_CTX_set_ecdh_cofactor_mode(pctx, cofactor) <= 0)
936 if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, EVP_PKEY_ECDH_KDF_X9_63) <= 0)
939 kdf_md = EVP_get_digestbynid(kdfmd_nid);
943 if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
948 static int ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
952 X509_ALGOR *alg, *kekalg = NULL;
953 ASN1_OCTET_STRING *ukm;
954 const unsigned char *p;
955 unsigned char *der = NULL;
957 const EVP_CIPHER *kekcipher;
958 EVP_CIPHER_CTX *kekctx;
960 if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
963 if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) {
964 ECerr(EC_F_ECDH_CMS_SET_SHARED_INFO, EC_R_KDF_PARAMETER_ERROR);
968 if (alg->parameter->type != V_ASN1_SEQUENCE)
971 p = alg->parameter->value.sequence->data;
972 plen = alg->parameter->value.sequence->length;
973 kekalg = d2i_X509_ALGOR(NULL, &p, plen);
976 kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
979 kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
980 if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
982 if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
984 if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
987 keylen = EVP_CIPHER_CTX_key_length(kekctx);
988 if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
991 plen = CMS_SharedInfo_encode(&der, kekalg, ukm, keylen);
996 if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
1002 X509_ALGOR_free(kekalg);
1007 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri)
1010 pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
1013 /* See if we need to set peer key */
1014 if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
1016 ASN1_BIT_STRING *pubkey;
1017 if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
1020 if (!alg || !pubkey)
1022 if (!ecdh_cms_set_peerkey(pctx, alg, pubkey)) {
1023 ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_PEER_KEY_ERROR);
1027 /* Set ECDH derivation parameters and initialise unwrap context */
1028 if (!ecdh_cms_set_shared_info(pctx, ri)) {
1029 ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_SHARED_INFO_ERROR);
1035 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri)
1039 EVP_CIPHER_CTX *ctx;
1041 X509_ALGOR *talg, *wrap_alg = NULL;
1042 const ASN1_OBJECT *aoid;
1043 ASN1_BIT_STRING *pubkey;
1044 ASN1_STRING *wrap_str;
1045 ASN1_OCTET_STRING *ukm;
1046 unsigned char *penc = NULL;
1049 int ecdh_nid, kdf_type, kdf_nid, wrap_nid;
1050 const EVP_MD *kdf_md;
1051 pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
1054 /* Get ephemeral key */
1055 pkey = EVP_PKEY_CTX_get0_pkey(pctx);
1056 if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
1059 X509_ALGOR_get0(&aoid, NULL, NULL, talg);
1060 /* Is everything uninitialised? */
1061 if (aoid == OBJ_nid2obj(NID_undef)) {
1063 EC_KEY *eckey = pkey->pkey.ec;
1067 penclen = i2o_ECPublicKey(eckey, NULL);
1070 penc = OPENSSL_malloc(penclen);
1074 penclen = i2o_ECPublicKey(eckey, &p);
1077 ASN1_STRING_set0(pubkey, penc, penclen);
1078 pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
1079 pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
1082 X509_ALGOR_set0(talg, OBJ_nid2obj(NID_X9_62_id_ecPublicKey),
1083 V_ASN1_UNDEF, NULL);
1086 /* See if custom parameters set */
1087 kdf_type = EVP_PKEY_CTX_get_ecdh_kdf_type(pctx);
1090 if (!EVP_PKEY_CTX_get_ecdh_kdf_md(pctx, &kdf_md))
1092 ecdh_nid = EVP_PKEY_CTX_get_ecdh_cofactor_mode(pctx);
1095 else if (ecdh_nid == 0)
1096 ecdh_nid = NID_dh_std_kdf;
1097 else if (ecdh_nid == 1)
1098 ecdh_nid = NID_dh_cofactor_kdf;
1100 if (kdf_type == EVP_PKEY_ECDH_KDF_NONE) {
1101 kdf_type = EVP_PKEY_ECDH_KDF_X9_63;
1102 if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0)
1107 if (kdf_md == NULL) {
1108 /* Fixme later for better MD */
1109 kdf_md = EVP_sha1();
1110 if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
1114 if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
1117 /* Lookup NID for KDF+cofactor+digest */
1119 if (!OBJ_find_sigid_by_algs(&kdf_nid, EVP_MD_type(kdf_md), ecdh_nid))
1122 ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
1123 wrap_nid = EVP_CIPHER_CTX_type(ctx);
1124 keylen = EVP_CIPHER_CTX_key_length(ctx);
1126 /* Package wrap algorithm in an AlgorithmIdentifier */
1128 wrap_alg = X509_ALGOR_new();
1129 if (wrap_alg == NULL)
1131 wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
1132 wrap_alg->parameter = ASN1_TYPE_new();
1133 if (wrap_alg->parameter == NULL)
1135 if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
1137 if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
1138 ASN1_TYPE_free(wrap_alg->parameter);
1139 wrap_alg->parameter = NULL;
1142 if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
1145 penclen = CMS_SharedInfo_encode(&penc, wrap_alg, ukm, keylen);
1150 if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, penc, penclen) <= 0)
1155 * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
1156 * of another AlgorithmIdentifier.
1158 penclen = i2d_X509_ALGOR(wrap_alg, &penc);
1159 if (!penc || !penclen)
1161 wrap_str = ASN1_STRING_new();
1162 if (wrap_str == NULL)
1164 ASN1_STRING_set0(wrap_str, penc, penclen);
1166 X509_ALGOR_set0(talg, OBJ_nid2obj(kdf_nid), V_ASN1_SEQUENCE, wrap_str);
1172 X509_ALGOR_free(wrap_alg);