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/asn1t.h>
22 #include "crypto/asn1.h"
23 #include "crypto/evp.h"
24 #include "crypto/x509.h"
25 #include <openssl/core_names.h>
26 #include "openssl/param_build.h"
29 static int eckey_param2type(int *pptype, void **ppval, const EC_KEY *ec_key)
31 const EC_GROUP *group;
34 if (ec_key == NULL || (group = EC_KEY_get0_group(ec_key)) == NULL) {
35 ECerr(EC_F_ECKEY_PARAM2TYPE, EC_R_MISSING_PARAMETERS);
38 if (EC_GROUP_get_asn1_flag(group)
39 && (nid = EC_GROUP_get_curve_name(group)))
40 /* we have a 'named curve' => just set the OID */
42 ASN1_OBJECT *asn1obj = OBJ_nid2obj(nid);
44 if (asn1obj == NULL || OBJ_length(asn1obj) == 0) {
45 ASN1_OBJECT_free(asn1obj);
46 ECerr(EC_F_ECKEY_PARAM2TYPE, EC_R_MISSING_OID);
50 *pptype = V_ASN1_OBJECT;
51 } else { /* explicit parameters */
53 ASN1_STRING *pstr = NULL;
54 pstr = ASN1_STRING_new();
57 pstr->length = i2d_ECParameters(ec_key, &pstr->data);
58 if (pstr->length <= 0) {
59 ASN1_STRING_free(pstr);
60 ECerr(EC_F_ECKEY_PARAM2TYPE, ERR_R_EC_LIB);
64 *pptype = V_ASN1_SEQUENCE;
69 static int eckey_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
71 const EC_KEY *ec_key = pkey->pkey.ec;
74 unsigned char *penc = NULL, *p;
77 if (!eckey_param2type(&ptype, &pval, ec_key)) {
78 ECerr(EC_F_ECKEY_PUB_ENCODE, ERR_R_EC_LIB);
81 penclen = i2o_ECPublicKey(ec_key, NULL);
84 penc = OPENSSL_malloc(penclen);
88 penclen = i2o_ECPublicKey(ec_key, &p);
91 if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(EVP_PKEY_EC),
92 ptype, pval, penc, penclen))
95 if (ptype == V_ASN1_OBJECT)
96 ASN1_OBJECT_free(pval);
98 ASN1_STRING_free(pval);
103 static EC_KEY *eckey_type2param(int ptype, const void *pval,
104 OSSL_LIB_CTX *libctx, const char *propq)
106 EC_KEY *eckey = NULL;
107 EC_GROUP *group = NULL;
109 if ((eckey = EC_KEY_new_ex(libctx, propq)) == NULL) {
110 ECerr(EC_F_ECKEY_TYPE2PARAM, ERR_R_MALLOC_FAILURE);
114 if (ptype == V_ASN1_SEQUENCE) {
115 const ASN1_STRING *pstr = pval;
116 const unsigned char *pm = pstr->data;
117 int pmlen = pstr->length;
120 if (d2i_ECParameters(&eckey, &pm, pmlen) == NULL) {
121 ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
124 } else if (ptype == V_ASN1_OBJECT) {
125 const ASN1_OBJECT *poid = pval;
128 * type == V_ASN1_OBJECT => the parameters are given by an asn1 OID
131 group = EC_GROUP_new_by_curve_name_ex(libctx, propq, OBJ_obj2nid(poid));
134 EC_GROUP_set_asn1_flag(group, OPENSSL_EC_NAMED_CURVE);
135 if (EC_KEY_set_group(eckey, group) == 0)
137 EC_GROUP_free(group);
139 ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
147 EC_GROUP_free(group);
151 static int eckey_pub_decode(EVP_PKEY *pkey, const X509_PUBKEY *pubkey)
153 const unsigned char *p = NULL;
156 EC_KEY *eckey = NULL;
158 OSSL_LIB_CTX *libctx = NULL;
159 const char *propq = NULL;
161 if (!X509_PUBKEY_get0_libctx(&libctx, &propq, pubkey)
162 || !X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
164 X509_ALGOR_get0(NULL, &ptype, &pval, palg);
166 eckey = eckey_type2param(ptype, pval, libctx, propq);
171 /* We have parameters now set public key */
172 if (!o2i_ECPublicKey(&eckey, &p, pklen)) {
173 ECerr(EC_F_ECKEY_PUB_DECODE, EC_R_DECODE_ERROR);
177 EVP_PKEY_assign_EC_KEY(pkey, eckey);
185 static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
188 const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec);
189 const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec),
190 *pb = EC_KEY_get0_public_key(b->pkey.ec);
192 if (group == NULL || pa == NULL || pb == NULL)
194 r = EC_POINT_cmp(group, pa, pb, NULL);
202 static int eckey_priv_decode_ex(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8,
203 OSSL_LIB_CTX *libctx, const char *propq)
205 const unsigned char *p = NULL;
208 EC_KEY *eckey = NULL;
209 const X509_ALGOR *palg;
211 if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
213 X509_ALGOR_get0(NULL, &ptype, &pval, palg);
215 eckey = eckey_type2param(ptype, pval, libctx, propq);
219 /* We have parameters now set private key */
220 if (!d2i_ECPrivateKey(&eckey, &p, pklen)) {
221 ECerr(0, EC_R_DECODE_ERROR);
225 EVP_PKEY_assign_EC_KEY(pkey, eckey);
233 static int eckey_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
235 EC_KEY ec_key = *(pkey->pkey.ec);
236 unsigned char *ep, *p;
239 unsigned int old_flags;
241 if (!eckey_param2type(&ptype, &pval, &ec_key)) {
242 ECerr(EC_F_ECKEY_PRIV_ENCODE, EC_R_DECODE_ERROR);
246 /* set the private key */
249 * do not include the parameters in the SEC1 private key see PKCS#11
252 old_flags = EC_KEY_get_enc_flags(&ec_key);
253 EC_KEY_set_enc_flags(&ec_key, old_flags | EC_PKEY_NO_PARAMETERS);
255 eplen = i2d_ECPrivateKey(&ec_key, NULL);
257 ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
260 ep = OPENSSL_malloc(eplen);
262 ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
266 if (!i2d_ECPrivateKey(&ec_key, &p)) {
268 ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
272 if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0,
273 ptype, pval, ep, eplen)) {
281 static int int_ec_size(const EVP_PKEY *pkey)
283 return ECDSA_size(pkey->pkey.ec);
286 static int ec_bits(const EVP_PKEY *pkey)
288 return EC_GROUP_order_bits(EC_KEY_get0_group(pkey->pkey.ec));
291 static int ec_security_bits(const EVP_PKEY *pkey)
293 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);
340 if (group_a == NULL || group_b == NULL)
342 if (EC_GROUP_cmp(group_a, group_b, NULL))
348 static void int_ec_free(EVP_PKEY *pkey)
350 EC_KEY_free(pkey->pkey.ec);
354 EC_KEY_PRINT_PRIVATE,
359 static int do_EC_KEY_print(BIO *bp, const EC_KEY *x, int off, ec_print_t ktype)
362 unsigned char *priv = NULL, *pub = NULL;
363 size_t privlen = 0, publen = 0;
365 const EC_GROUP *group;
367 if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL) {
368 ECerr(EC_F_DO_EC_KEY_PRINT, ERR_R_PASSED_NULL_PARAMETER);
372 if (ktype != EC_KEY_PRINT_PARAM && EC_KEY_get0_public_key(x) != NULL) {
373 publen = EC_KEY_key2buf(x, EC_KEY_get_conv_form(x), &pub, NULL);
378 if (ktype == EC_KEY_PRINT_PRIVATE && EC_KEY_get0_private_key(x) != NULL) {
379 privlen = EC_KEY_priv2buf(x, &priv);
384 if (ktype == EC_KEY_PRINT_PRIVATE)
385 ecstr = "Private-Key";
386 else if (ktype == EC_KEY_PRINT_PUBLIC)
387 ecstr = "Public-Key";
389 ecstr = "ECDSA-Parameters";
391 if (!BIO_indent(bp, off, 128))
393 if (BIO_printf(bp, "%s: (%d bit)\n", ecstr,
394 EC_GROUP_order_bits(group)) <= 0)
398 if (BIO_printf(bp, "%*spriv:\n", off, "") <= 0)
400 if (ASN1_buf_print(bp, priv, privlen, off + 4) == 0)
405 if (BIO_printf(bp, "%*spub:\n", off, "") <= 0)
407 if (ASN1_buf_print(bp, pub, publen, off + 4) == 0)
411 if (!ECPKParameters_print(bp, group, off))
416 ECerr(EC_F_DO_EC_KEY_PRINT, ERR_R_EC_LIB);
417 OPENSSL_clear_free(priv, privlen);
422 static int eckey_param_decode(EVP_PKEY *pkey,
423 const unsigned char **pder, int derlen)
427 if ((eckey = d2i_ECParameters(NULL, pder, derlen)) == NULL)
429 EVP_PKEY_assign_EC_KEY(pkey, eckey);
433 static int eckey_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
435 return i2d_ECParameters(pkey->pkey.ec, pder);
438 static int eckey_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
441 return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PARAM);
444 static int eckey_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
447 return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PUBLIC);
450 static int eckey_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
453 return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PRIVATE);
456 static int old_ec_priv_decode(EVP_PKEY *pkey,
457 const unsigned char **pder, int derlen)
461 if ((ec = d2i_ECPrivateKey(NULL, pder, derlen)) == NULL)
463 EVP_PKEY_assign_EC_KEY(pkey, ec);
467 static int old_ec_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
469 return i2d_ECPrivateKey(pkey->pkey.ec, pder);
472 static int ec_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
475 case ASN1_PKEY_CTRL_PKCS7_SIGN:
478 X509_ALGOR *alg1, *alg2;
480 PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2);
481 if (alg1 == NULL || alg1->algorithm == NULL)
483 hnid = OBJ_obj2nid(alg1->algorithm);
484 if (hnid == NID_undef)
486 if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
488 X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
492 case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
493 if (EVP_PKEY_id(pkey) == EVP_PKEY_SM2) {
494 /* For SM2, the only valid digest-alg is SM3 */
495 *(int *)arg2 = NID_sm3;
496 return 2; /* Make it mandatory */
498 *(int *)arg2 = NID_sha256;
501 case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
502 return EC_KEY_oct2key(EVP_PKEY_get0_EC_KEY(pkey), arg2, arg1, NULL);
504 case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
505 return EC_KEY_key2buf(EVP_PKEY_get0_EC_KEY(pkey),
506 POINT_CONVERSION_UNCOMPRESSED, arg2, NULL);
515 static int ec_pkey_check(const EVP_PKEY *pkey)
517 EC_KEY *eckey = pkey->pkey.ec;
519 /* stay consistent to what EVP_PKEY_check demands */
520 if (eckey->priv_key == NULL) {
521 ECerr(EC_F_EC_PKEY_CHECK, EC_R_MISSING_PRIVATE_KEY);
525 return EC_KEY_check_key(eckey);
528 static int ec_pkey_public_check(const EVP_PKEY *pkey)
530 EC_KEY *eckey = pkey->pkey.ec;
533 * Note: it unnecessary to check eckey->pub_key here since
534 * it will be checked in EC_KEY_check_key(). In fact, the
535 * EC_KEY_check_key() mainly checks the public key, and checks
536 * the private key optionally (only if there is one). So if
537 * someone passes a whole EC key (public + private), this
541 return EC_KEY_check_key(eckey);
544 static int ec_pkey_param_check(const EVP_PKEY *pkey)
546 EC_KEY *eckey = pkey->pkey.ec;
548 /* stay consistent to what EVP_PKEY_check demands */
549 if (eckey->group == NULL) {
550 ECerr(EC_F_EC_PKEY_PARAM_CHECK, EC_R_MISSING_PARAMETERS);
554 return EC_GROUP_check(eckey->group, NULL);
558 size_t ec_pkey_dirty_cnt(const EVP_PKEY *pkey)
560 return pkey->pkey.ec->dirty_cnt;
564 int ec_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
565 EVP_KEYMGMT *to_keymgmt, OSSL_LIB_CTX *libctx,
568 const EC_KEY *eckey = NULL;
569 const EC_GROUP *ecg = NULL;
570 unsigned char *pub_key_buf = NULL, *gen_buf = NULL;
571 size_t pub_key_buflen;
572 OSSL_PARAM_BLD *tmpl;
573 OSSL_PARAM *params = NULL;
574 const BIGNUM *priv_key = NULL;
575 const EC_POINT *pub_point = NULL;
578 BN_CTX *bnctx = NULL;
581 || (eckey = from->pkey.ec) == NULL
582 || (ecg = EC_KEY_get0_group(eckey)) == NULL)
586 * If the EC_KEY method is foreign, then we can't be sure of anything,
587 * and can therefore not export or pretend to export.
589 if (EC_KEY_get_method(eckey) != EC_KEY_OpenSSL())
592 tmpl = OSSL_PARAM_BLD_new();
597 * EC_POINT_point2buf() can generate random numbers in some
598 * implementations so we need to ensure we use the correct libctx.
600 bnctx = BN_CTX_new_ex(libctx);
605 /* export the domain parameters */
606 if (!ec_group_todata(ecg, tmpl, NULL, libctx, propq, bnctx, &gen_buf))
608 selection |= OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS;
610 priv_key = EC_KEY_get0_private_key(eckey);
611 pub_point = EC_KEY_get0_public_key(eckey);
613 if (pub_point != NULL) {
614 /* convert pub_point to a octet string according to the SECG standard */
615 if ((pub_key_buflen = EC_POINT_point2buf(ecg, pub_point,
616 POINT_CONVERSION_COMPRESSED,
617 &pub_key_buf, bnctx)) == 0
618 || !OSSL_PARAM_BLD_push_octet_string(tmpl,
619 OSSL_PKEY_PARAM_PUB_KEY,
623 selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
626 if (priv_key != NULL) {
629 int ecdh_cofactor_mode;
632 * Key import/export should never leak the bit length of the secret
635 * For this reason, on export we use padded BIGNUMs with fixed length.
637 * When importing we also should make sure that, even if short lived,
638 * the newly created BIGNUM is marked with the BN_FLG_CONSTTIME flag as
639 * soon as possible, so that any processing of this BIGNUM might opt for
640 * constant time implementations in the backend.
642 * Setting the BN_FLG_CONSTTIME flag alone is never enough, we also have
643 * to preallocate the BIGNUM internal buffer to a fixed public size big
644 * enough that operations performed during the processing never trigger
645 * a realloc which would leak the size of the scalar through memory
651 * The order of the large prime subgroup of the curve is our choice for
652 * a fixed public size, as that is generally the upper bound for
653 * generating a private key in EC cryptosystems and should fit all valid
656 * For padding on export we just use the bit length of the order
657 * converted to bytes (rounding up).
659 * For preallocating the BIGNUM storage we look at the number of "words"
660 * required for the internal representation of the order, and we
661 * preallocate 2 extra "words" in case any of the subsequent processing
662 * might temporarily overflow the order length.
664 ecbits = EC_GROUP_order_bits(ecg);
668 sz = (ecbits + 7 ) / 8;
669 if (!OSSL_PARAM_BLD_push_BN_pad(tmpl,
670 OSSL_PKEY_PARAM_PRIV_KEY,
673 selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
676 * The ECDH Cofactor Mode is defined only if the EC_KEY actually
677 * contains a private key, so we check for the flag and export it only
681 (EC_KEY_get_flags(eckey) & EC_FLAG_COFACTOR_ECDH) ? 1 : 0;
683 /* Export the ECDH_COFACTOR_MODE parameter */
684 if (!OSSL_PARAM_BLD_push_int(tmpl,
685 OSSL_PKEY_PARAM_USE_COFACTOR_ECDH,
688 selection |= OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS;
691 params = OSSL_PARAM_BLD_to_param(tmpl);
693 /* We export, the provider imports */
694 rv = evp_keymgmt_import(to_keymgmt, to_keydata, selection, params);
697 OSSL_PARAM_BLD_free(tmpl);
698 OSSL_PARAM_BLD_free_params(params);
699 OPENSSL_free(pub_key_buf);
700 OPENSSL_free(gen_buf);
706 static int ec_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
708 EVP_PKEY_CTX *pctx = vpctx;
709 EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
710 EC_KEY *ec = EC_KEY_new_ex(pctx->libctx, pctx->propquery);
713 ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
717 if (!ec_group_fromdata(ec, params)
718 || !ec_key_otherparams_fromdata(ec, params)
719 || !ec_key_fromdata(ec, params, 1)
720 || !EVP_PKEY_assign_EC_KEY(pkey, ec)) {
727 const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = {
732 "OpenSSL EC algorithm",
749 ec_missing_parameters,
763 ec_pkey_public_check,
766 0, /* set_priv_key */
768 0, /* get_priv_key */
777 #if !defined(OPENSSL_NO_SM2)
778 const EVP_PKEY_ASN1_METHOD sm2_asn1_meth = {
785 int EC_KEY_print(BIO *bp, const EC_KEY *x, int off)
787 int private = EC_KEY_get0_private_key(x) != NULL;
789 return do_EC_KEY_print(bp, x, off,
790 private ? EC_KEY_PRINT_PRIVATE : EC_KEY_PRINT_PUBLIC);
793 int ECParameters_print(BIO *bp, const EC_KEY *x)
795 return do_EC_KEY_print(bp, x, 4, EC_KEY_PRINT_PARAM);