2 * Copyright 2006-2021 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 ERR_raise(ERR_LIB_EC
, 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 ERR_raise(ERR_LIB_EC
, 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 ERR_raise(ERR_LIB_EC
, 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 ERR_raise(ERR_LIB_EC
, 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 int eckey_pub_decode(EVP_PKEY
*pkey
, const X509_PUBKEY
*pubkey
)
105 const unsigned char *p
= NULL
;
107 EC_KEY
*eckey
= NULL
;
109 OSSL_LIB_CTX
*libctx
= NULL
;
110 const char *propq
= NULL
;
112 if (!ossl_x509_PUBKEY_get0_libctx(&libctx
, &propq
, pubkey
)
113 || !X509_PUBKEY_get0_param(NULL
, &p
, &pklen
, &palg
, pubkey
))
115 eckey
= ossl_ec_key_param_from_x509_algor(palg
, libctx
, propq
);
120 /* We have parameters now set public key */
121 if (!o2i_ECPublicKey(&eckey
, &p
, pklen
)) {
122 ERR_raise(ERR_LIB_EC
, EC_R_DECODE_ERROR
);
126 EVP_PKEY_assign_EC_KEY(pkey
, eckey
);
134 static int eckey_pub_cmp(const EVP_PKEY
*a
, const EVP_PKEY
*b
)
137 const EC_GROUP
*group
= EC_KEY_get0_group(b
->pkey
.ec
);
138 const EC_POINT
*pa
= EC_KEY_get0_public_key(a
->pkey
.ec
),
139 *pb
= EC_KEY_get0_public_key(b
->pkey
.ec
);
141 if (group
== NULL
|| pa
== NULL
|| pb
== NULL
)
143 r
= EC_POINT_cmp(group
, pa
, pb
, NULL
);
151 static int eckey_priv_decode_ex(EVP_PKEY
*pkey
, const PKCS8_PRIV_KEY_INFO
*p8
,
152 OSSL_LIB_CTX
*libctx
, const char *propq
)
155 EC_KEY
*eckey
= ossl_ec_key_from_pkcs8(p8
, libctx
, propq
);
159 EVP_PKEY_assign_EC_KEY(pkey
, eckey
);
165 static int eckey_priv_encode(PKCS8_PRIV_KEY_INFO
*p8
, const EVP_PKEY
*pkey
)
167 EC_KEY ec_key
= *(pkey
->pkey
.ec
);
168 unsigned char *ep
, *p
;
171 unsigned int old_flags
;
173 if (!eckey_param2type(&ptype
, &pval
, &ec_key
)) {
174 ERR_raise(ERR_LIB_EC
, EC_R_DECODE_ERROR
);
178 /* set the private key */
181 * do not include the parameters in the SEC1 private key see PKCS#11
184 old_flags
= EC_KEY_get_enc_flags(&ec_key
);
185 EC_KEY_set_enc_flags(&ec_key
, old_flags
| EC_PKEY_NO_PARAMETERS
);
187 eplen
= i2d_ECPrivateKey(&ec_key
, NULL
);
189 ERR_raise(ERR_LIB_EC
, ERR_R_EC_LIB
);
192 ep
= OPENSSL_malloc(eplen
);
194 ERR_raise(ERR_LIB_EC
, ERR_R_MALLOC_FAILURE
);
198 if (!i2d_ECPrivateKey(&ec_key
, &p
)) {
200 ERR_raise(ERR_LIB_EC
, ERR_R_EC_LIB
);
204 if (!PKCS8_pkey_set0(p8
, OBJ_nid2obj(NID_X9_62_id_ecPublicKey
), 0,
205 ptype
, pval
, ep
, eplen
)) {
213 static int int_ec_size(const EVP_PKEY
*pkey
)
215 return ECDSA_size(pkey
->pkey
.ec
);
218 static int ec_bits(const EVP_PKEY
*pkey
)
220 return EC_GROUP_order_bits(EC_KEY_get0_group(pkey
->pkey
.ec
));
223 static int ec_security_bits(const EVP_PKEY
*pkey
)
225 int ecbits
= ec_bits(pkey
);
240 static int ec_missing_parameters(const EVP_PKEY
*pkey
)
242 if (pkey
->pkey
.ec
== NULL
|| EC_KEY_get0_group(pkey
->pkey
.ec
) == NULL
)
247 static int ec_copy_parameters(EVP_PKEY
*to
, const EVP_PKEY
*from
)
249 EC_GROUP
*group
= EC_GROUP_dup(EC_KEY_get0_group(from
->pkey
.ec
));
253 if (to
->pkey
.ec
== NULL
) {
254 to
->pkey
.ec
= EC_KEY_new();
255 if (to
->pkey
.ec
== NULL
)
258 if (EC_KEY_set_group(to
->pkey
.ec
, group
) == 0)
260 EC_GROUP_free(group
);
263 EC_GROUP_free(group
);
267 static int ec_cmp_parameters(const EVP_PKEY
*a
, const EVP_PKEY
*b
)
269 const EC_GROUP
*group_a
= EC_KEY_get0_group(a
->pkey
.ec
),
270 *group_b
= EC_KEY_get0_group(b
->pkey
.ec
);
272 if (group_a
== NULL
|| group_b
== NULL
)
274 if (EC_GROUP_cmp(group_a
, group_b
, NULL
))
280 static void int_ec_free(EVP_PKEY
*pkey
)
282 EC_KEY_free(pkey
->pkey
.ec
);
286 EC_KEY_PRINT_PRIVATE
,
291 static int do_EC_KEY_print(BIO
*bp
, const EC_KEY
*x
, int off
, ec_print_t ktype
)
294 unsigned char *priv
= NULL
, *pub
= NULL
;
295 size_t privlen
= 0, publen
= 0;
297 const EC_GROUP
*group
;
299 if (x
== NULL
|| (group
= EC_KEY_get0_group(x
)) == NULL
) {
300 ERR_raise(ERR_LIB_EC
, ERR_R_PASSED_NULL_PARAMETER
);
304 if (ktype
!= EC_KEY_PRINT_PARAM
&& EC_KEY_get0_public_key(x
) != NULL
) {
305 publen
= EC_KEY_key2buf(x
, EC_KEY_get_conv_form(x
), &pub
, NULL
);
310 if (ktype
== EC_KEY_PRINT_PRIVATE
&& EC_KEY_get0_private_key(x
) != NULL
) {
311 privlen
= EC_KEY_priv2buf(x
, &priv
);
316 if (ktype
== EC_KEY_PRINT_PRIVATE
)
317 ecstr
= "Private-Key";
318 else if (ktype
== EC_KEY_PRINT_PUBLIC
)
319 ecstr
= "Public-Key";
321 ecstr
= "ECDSA-Parameters";
323 if (!BIO_indent(bp
, off
, 128))
325 if (BIO_printf(bp
, "%s: (%d bit)\n", ecstr
,
326 EC_GROUP_order_bits(group
)) <= 0)
330 if (BIO_printf(bp
, "%*spriv:\n", off
, "") <= 0)
332 if (ASN1_buf_print(bp
, priv
, privlen
, off
+ 4) == 0)
337 if (BIO_printf(bp
, "%*spub:\n", off
, "") <= 0)
339 if (ASN1_buf_print(bp
, pub
, publen
, off
+ 4) == 0)
343 if (!ECPKParameters_print(bp
, group
, off
))
348 ERR_raise(ERR_LIB_EC
, ERR_R_EC_LIB
);
349 OPENSSL_clear_free(priv
, privlen
);
354 static int eckey_param_decode(EVP_PKEY
*pkey
,
355 const unsigned char **pder
, int derlen
)
359 if ((eckey
= d2i_ECParameters(NULL
, pder
, derlen
)) == NULL
)
361 EVP_PKEY_assign_EC_KEY(pkey
, eckey
);
365 static int eckey_param_encode(const EVP_PKEY
*pkey
, unsigned char **pder
)
367 return i2d_ECParameters(pkey
->pkey
.ec
, pder
);
370 static int eckey_param_print(BIO
*bp
, const EVP_PKEY
*pkey
, int indent
,
373 return do_EC_KEY_print(bp
, pkey
->pkey
.ec
, indent
, EC_KEY_PRINT_PARAM
);
376 static int eckey_pub_print(BIO
*bp
, const EVP_PKEY
*pkey
, int indent
,
379 return do_EC_KEY_print(bp
, pkey
->pkey
.ec
, indent
, EC_KEY_PRINT_PUBLIC
);
382 static int eckey_priv_print(BIO
*bp
, const EVP_PKEY
*pkey
, int indent
,
385 return do_EC_KEY_print(bp
, pkey
->pkey
.ec
, indent
, EC_KEY_PRINT_PRIVATE
);
388 static int old_ec_priv_decode(EVP_PKEY
*pkey
,
389 const unsigned char **pder
, int derlen
)
393 if ((ec
= d2i_ECPrivateKey(NULL
, pder
, derlen
)) == NULL
)
395 EVP_PKEY_assign_EC_KEY(pkey
, ec
);
399 static int old_ec_priv_encode(const EVP_PKEY
*pkey
, unsigned char **pder
)
401 return i2d_ECPrivateKey(pkey
->pkey
.ec
, pder
);
404 static int ec_pkey_ctrl(EVP_PKEY
*pkey
, int op
, long arg1
, void *arg2
)
407 case ASN1_PKEY_CTRL_DEFAULT_MD_NID
:
408 if (EVP_PKEY_id(pkey
) == EVP_PKEY_SM2
) {
409 /* For SM2, the only valid digest-alg is SM3 */
410 *(int *)arg2
= NID_sm3
;
411 return 2; /* Make it mandatory */
413 *(int *)arg2
= NID_sha256
;
416 case ASN1_PKEY_CTRL_SET1_TLS_ENCPT
:
417 /* We should only be here if we have a legacy key */
418 if (!ossl_assert(evp_pkey_is_legacy(pkey
)))
420 return EC_KEY_oct2key(evp_pkey_get0_EC_KEY_int(pkey
), arg2
, arg1
, NULL
);
422 case ASN1_PKEY_CTRL_GET1_TLS_ENCPT
:
423 return EC_KEY_key2buf(EVP_PKEY_get0_EC_KEY(pkey
),
424 POINT_CONVERSION_UNCOMPRESSED
, arg2
, NULL
);
431 static int ec_pkey_check(const EVP_PKEY
*pkey
)
433 EC_KEY
*eckey
= pkey
->pkey
.ec
;
435 /* stay consistent to what EVP_PKEY_check demands */
436 if (eckey
->priv_key
== NULL
) {
437 ERR_raise(ERR_LIB_EC
, EC_R_MISSING_PRIVATE_KEY
);
441 return EC_KEY_check_key(eckey
);
444 static int ec_pkey_public_check(const EVP_PKEY
*pkey
)
446 EC_KEY
*eckey
= pkey
->pkey
.ec
;
449 * Note: it unnecessary to check eckey->pub_key here since
450 * it will be checked in EC_KEY_check_key(). In fact, the
451 * EC_KEY_check_key() mainly checks the public key, and checks
452 * the private key optionally (only if there is one). So if
453 * someone passes a whole EC key (public + private), this
457 return EC_KEY_check_key(eckey
);
460 static int ec_pkey_param_check(const EVP_PKEY
*pkey
)
462 EC_KEY
*eckey
= pkey
->pkey
.ec
;
464 /* stay consistent to what EVP_PKEY_check demands */
465 if (eckey
->group
== NULL
) {
466 ERR_raise(ERR_LIB_EC
, EC_R_MISSING_PARAMETERS
);
470 return EC_GROUP_check(eckey
->group
, NULL
);
474 size_t ec_pkey_dirty_cnt(const EVP_PKEY
*pkey
)
476 return pkey
->pkey
.ec
->dirty_cnt
;
480 int ec_pkey_export_to(const EVP_PKEY
*from
, void *to_keydata
,
481 OSSL_FUNC_keymgmt_import_fn
*importer
,
482 OSSL_LIB_CTX
*libctx
, const char *propq
)
484 const EC_KEY
*eckey
= NULL
;
485 const EC_GROUP
*ecg
= NULL
;
486 unsigned char *pub_key_buf
= NULL
, *gen_buf
= NULL
;
487 size_t pub_key_buflen
;
488 OSSL_PARAM_BLD
*tmpl
;
489 OSSL_PARAM
*params
= NULL
;
490 const BIGNUM
*priv_key
= NULL
;
491 const EC_POINT
*pub_point
= NULL
;
494 BN_CTX
*bnctx
= NULL
;
497 || (eckey
= from
->pkey
.ec
) == NULL
498 || (ecg
= EC_KEY_get0_group(eckey
)) == NULL
)
502 * If the EC_KEY method is foreign, then we can't be sure of anything,
503 * and can therefore not export or pretend to export.
505 if (EC_KEY_get_method(eckey
) != EC_KEY_OpenSSL())
508 tmpl
= OSSL_PARAM_BLD_new();
513 * EC_POINT_point2buf() can generate random numbers in some
514 * implementations so we need to ensure we use the correct libctx.
516 bnctx
= BN_CTX_new_ex(libctx
);
521 /* export the domain parameters */
522 if (!ossl_ec_group_todata(ecg
, tmpl
, NULL
, libctx
, propq
, bnctx
, &gen_buf
))
524 selection
|= OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS
;
526 priv_key
= EC_KEY_get0_private_key(eckey
);
527 pub_point
= EC_KEY_get0_public_key(eckey
);
529 if (pub_point
!= NULL
) {
530 /* convert pub_point to a octet string according to the SECG standard */
531 if ((pub_key_buflen
= EC_POINT_point2buf(ecg
, pub_point
,
532 POINT_CONVERSION_COMPRESSED
,
533 &pub_key_buf
, bnctx
)) == 0
534 || !OSSL_PARAM_BLD_push_octet_string(tmpl
,
535 OSSL_PKEY_PARAM_PUB_KEY
,
539 selection
|= OSSL_KEYMGMT_SELECT_PUBLIC_KEY
;
542 if (priv_key
!= NULL
) {
545 int ecdh_cofactor_mode
;
548 * Key import/export should never leak the bit length of the secret
551 * For this reason, on export we use padded BIGNUMs with fixed length.
553 * When importing we also should make sure that, even if short lived,
554 * the newly created BIGNUM is marked with the BN_FLG_CONSTTIME flag as
555 * soon as possible, so that any processing of this BIGNUM might opt for
556 * constant time implementations in the backend.
558 * Setting the BN_FLG_CONSTTIME flag alone is never enough, we also have
559 * to preallocate the BIGNUM internal buffer to a fixed public size big
560 * enough that operations performed during the processing never trigger
561 * a realloc which would leak the size of the scalar through memory
567 * The order of the large prime subgroup of the curve is our choice for
568 * a fixed public size, as that is generally the upper bound for
569 * generating a private key in EC cryptosystems and should fit all valid
572 * For padding on export we just use the bit length of the order
573 * converted to bytes (rounding up).
575 * For preallocating the BIGNUM storage we look at the number of "words"
576 * required for the internal representation of the order, and we
577 * preallocate 2 extra "words" in case any of the subsequent processing
578 * might temporarily overflow the order length.
580 ecbits
= EC_GROUP_order_bits(ecg
);
584 sz
= (ecbits
+ 7 ) / 8;
585 if (!OSSL_PARAM_BLD_push_BN_pad(tmpl
,
586 OSSL_PKEY_PARAM_PRIV_KEY
,
589 selection
|= OSSL_KEYMGMT_SELECT_PRIVATE_KEY
;
592 * The ECDH Cofactor Mode is defined only if the EC_KEY actually
593 * contains a private key, so we check for the flag and export it only
597 (EC_KEY_get_flags(eckey
) & EC_FLAG_COFACTOR_ECDH
) ? 1 : 0;
599 /* Export the ECDH_COFACTOR_MODE parameter */
600 if (!OSSL_PARAM_BLD_push_int(tmpl
,
601 OSSL_PKEY_PARAM_USE_COFACTOR_ECDH
,
604 selection
|= OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS
;
607 params
= OSSL_PARAM_BLD_to_param(tmpl
);
609 /* We export, the provider imports */
610 rv
= importer(to_keydata
, selection
, params
);
613 OSSL_PARAM_BLD_free(tmpl
);
614 OSSL_PARAM_free(params
);
615 OPENSSL_free(pub_key_buf
);
616 OPENSSL_free(gen_buf
);
622 static int ec_pkey_import_from(const OSSL_PARAM params
[], void *vpctx
)
624 EVP_PKEY_CTX
*pctx
= vpctx
;
625 EVP_PKEY
*pkey
= EVP_PKEY_CTX_get0_pkey(pctx
);
626 EC_KEY
*ec
= EC_KEY_new_ex(pctx
->libctx
, pctx
->propquery
);
629 ERR_raise(ERR_LIB_DH
, ERR_R_MALLOC_FAILURE
);
633 if (!ossl_ec_group_fromdata(ec
, params
)
634 || !ossl_ec_key_otherparams_fromdata(ec
, params
)
635 || !ossl_ec_key_fromdata(ec
, params
, 1)
636 || !EVP_PKEY_assign_EC_KEY(pkey
, ec
)) {
643 static int ec_pkey_copy(EVP_PKEY
*to
, EVP_PKEY
*from
)
645 EC_KEY
*eckey
= from
->pkey
.ec
;
646 EC_KEY
*dupkey
= NULL
;
650 dupkey
= EC_KEY_dup(eckey
);
654 /* necessary to properly copy empty SM2 keys */
655 return EVP_PKEY_set_type(to
, from
->type
);
658 ret
= EVP_PKEY_assign_EC_KEY(to
, dupkey
);
664 const EVP_PKEY_ASN1_METHOD ossl_eckey_asn1_meth
= {
669 "OpenSSL EC algorithm",
686 ec_missing_parameters
,
700 ec_pkey_public_check
,
703 0, /* set_priv_key */
705 0, /* get_priv_key */
715 #if !defined(OPENSSL_NO_SM2)
716 const EVP_PKEY_ASN1_METHOD ossl_sm2_asn1_meth
= {
723 int EC_KEY_print(BIO
*bp
, const EC_KEY
*x
, int off
)
725 int private = EC_KEY_get0_private_key(x
) != NULL
;
727 return do_EC_KEY_print(bp
, x
, off
,
728 private ? EC_KEY_PRINT_PRIVATE
: EC_KEY_PRINT_PUBLIC
);
731 int ECParameters_print(BIO
*bp
, const EC_KEY
*x
)
733 return do_EC_KEY_print(bp
, x
, 4, EC_KEY_PRINT_PARAM
);