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src/lib/libcrypto/ec/ec_ameth.c

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/* $OpenBSD: ec_ameth.c,v 1.52 2024/04/13 14:02:51 tb Exp $ */
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
* project 2006.
*/
/* ====================================================================
* Copyright (c) 2006 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* licensing@OpenSSL.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
#include <stdio.h>
#include <openssl/opensslconf.h>
#include <openssl/bn.h>
#include <openssl/cms.h>
#include <openssl/ec.h>
#include <openssl/err.h>
#include <openssl/x509.h>
#include "asn1_local.h"
#include "ec_local.h"
#include "evp_local.h"
#include "x509_local.h"
#ifndef OPENSSL_NO_CMS
static int ecdh_cms_decrypt(CMS_RecipientInfo *ri);
static int ecdh_cms_encrypt(CMS_RecipientInfo *ri);
#endif
static void
eckey_param_free(int ptype, void *pval)
{
if (pval == NULL)
return;
if (ptype == V_ASN1_OBJECT)
ASN1_OBJECT_free(pval); /* XXX - really necessary? */
else
ASN1_STRING_free(pval);
}
static int
eckey_get_curve_name(const EC_KEY *eckey, int *nid)
{
const EC_GROUP *group;
*nid = NID_undef;
if ((group = EC_KEY_get0_group(eckey)) == NULL) {
ECerror(EC_R_MISSING_PARAMETERS);
return 0;
}
if (EC_GROUP_get_asn1_flag(group) != 0)
*nid = EC_GROUP_get_curve_name(group);
return 1;
}
static int
eckey_to_explicit_params(EC_KEY *eckey, void **out_val)
{
ASN1_STRING *astr = NULL;
unsigned char *params = NULL;
int params_len = 0;
int ret = 0;
*out_val = NULL;
if ((params_len = i2d_ECParameters(eckey, &params)) <= 0) {
ECerror(ERR_R_EC_LIB);
params_len = 0;
goto err;
}
if ((astr = ASN1_STRING_new()) == NULL)
goto err;
ASN1_STRING_set0(astr, params, params_len);
params = NULL;
params_len = 0;
*out_val = astr;
astr = NULL;
ret = 1;
err:
freezero(params, params_len);
ASN1_STRING_free(astr);
return ret;
}
static int
eckey_from_explicit_params(const ASN1_STRING *astr, EC_KEY **out_eckey)
{
const unsigned char *params = astr->data;
int params_len = astr->length;
EC_KEY_free(*out_eckey);
if ((*out_eckey = d2i_ECParameters(NULL, &params, params_len)) == NULL) {
ECerror(EC_R_DECODE_ERROR);
return 0;
}
return 1;
}
static int
eckey_to_object(const EC_KEY *eckey, void **out_val)
{
int nid = NID_undef;
*out_val = NULL;
if (!eckey_get_curve_name(eckey, &nid))
return 0;
if ((*out_val = OBJ_nid2obj(nid)) == NULL)
return 0;
return 1;
}
static int
eckey_from_object(const ASN1_OBJECT *aobj, EC_KEY **out_eckey)
{
int nid;
*out_eckey = NULL;
if ((nid = OBJ_obj2nid(aobj)) == NID_undef)
return 0;
if ((*out_eckey = EC_KEY_new_by_curve_name(nid)) == NULL)
return 0;
return 1;
}
static int
eckey_to_params(EC_KEY *eckey, int *out_type, void **out_val)
{
int nid;
*out_type = NID_undef;
*out_val = NULL;
if (!eckey_get_curve_name(eckey, &nid))
return 0;
if (nid == NID_undef) {
*out_type = V_ASN1_SEQUENCE;
return eckey_to_explicit_params(eckey, out_val);
} else {
*out_type = V_ASN1_OBJECT;
return eckey_to_object(eckey, out_val);
}
}
static int
eckey_from_params(int ptype, const void *pval, EC_KEY **out_eckey)
{
*out_eckey = NULL;
if (ptype == V_ASN1_SEQUENCE)
return eckey_from_explicit_params(pval, out_eckey);
if (ptype == V_ASN1_OBJECT)
return eckey_from_object(pval, out_eckey);
ECerror(EC_R_DECODE_ERROR);
return 0;
}
static int
eckey_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
{
EC_KEY *eckey = pkey->pkey.ec;
int ptype = V_ASN1_UNDEF;
void *pval = NULL;
ASN1_OBJECT *aobj;
unsigned char *key = NULL;
int key_len = 0;
int ret = 0;
if (!eckey_to_params(eckey, &ptype, &pval)) {
ECerror(ERR_R_EC_LIB);
goto err;
}
if ((key_len = i2o_ECPublicKey(eckey, &key)) <= 0) {
key_len = 0;
goto err;
}
if ((aobj = OBJ_nid2obj(EVP_PKEY_EC)) == NULL)
goto err;
if (!X509_PUBKEY_set0_param(pk, aobj, ptype, pval, key, key_len))
goto err;
pval = NULL;
key = NULL;
key_len = 0;
ret = 1;
err:
eckey_param_free(ptype, pval);
freezero(key, key_len);
return ret;
}
static int
eckey_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
{
const unsigned char *p = NULL;
const void *pval;
int ptype, pklen;
EC_KEY *eckey = NULL;
X509_ALGOR *palg;
int ret = 0;
if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
goto err;
X509_ALGOR_get0(NULL, &ptype, &pval, palg);
if (!eckey_from_params(ptype, pval, &eckey))
goto err;
if (!o2i_ECPublicKey(&eckey, &p, pklen)) {
ECerror(EC_R_DECODE_ERROR);
goto err;
}
if (!EVP_PKEY_assign_EC_KEY(pkey, eckey))
goto err;
eckey = NULL;
ret = 1;
err:
EC_KEY_free(eckey);
return ret;
}
static int
eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
{
const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec);
const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec);
const EC_POINT *pb = EC_KEY_get0_public_key(b->pkey.ec);
int r;
r = EC_POINT_cmp(group, pa, pb, NULL);
if (r == 0)
return 1;
if (r == 1)
return 0;
return -2;
}
static int
eckey_compute_pubkey(EC_KEY *eckey)
{
const BIGNUM *priv_key;
const EC_GROUP *group;
EC_POINT *pub_key = NULL;
int ret = 0;
if ((priv_key = EC_KEY_get0_private_key(eckey)) == NULL)
goto err;
if ((group = EC_KEY_get0_group(eckey)) == NULL)
goto err;
if ((pub_key = EC_POINT_new(group)) == NULL)
goto err;
if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, NULL))
goto err;
if (!EC_KEY_set_public_key(eckey, pub_key))
goto err;
pub_key = NULL;
ret = 1;
err:
EC_POINT_free(pub_key);
return ret;
}
static int
eckey_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
{
const unsigned char *priv = NULL;
int priv_len;
const void *pval;
int ptype;
EC_KEY *eckey = NULL;
const X509_ALGOR *palg;
int ret = 0;
if (!PKCS8_pkey_get0(NULL, &priv, &priv_len, &palg, p8))
goto err;
X509_ALGOR_get0(NULL, &ptype, &pval, palg);
if (!eckey_from_params(ptype, pval, &eckey))
goto err;
/* Decode private key into eckey. */
if (d2i_ECPrivateKey(&eckey, &priv, priv_len) == NULL) {
ECerror(EC_R_DECODE_ERROR);
goto err;
}
/* If public key was missing from SEC1 key, compute it. */
if (EC_KEY_get0_public_key(eckey) == NULL) {
if (!eckey_compute_pubkey(eckey))
goto err;
}
if (!EVP_PKEY_assign_EC_KEY(pkey, eckey))
goto err;
eckey = NULL;
ret = 1;
err:
EC_KEY_free(eckey);
return ret;
}
static int
eckey_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
{
EC_KEY *eckey = pkey->pkey.ec;
void *pval = NULL;
int ptype = V_ASN1_UNDEF;
ASN1_OBJECT *aobj;
unsigned char *key = NULL;
int key_len = 0;
unsigned int flags;
int ret = 0;
flags = EC_KEY_get_enc_flags(eckey);
if (!eckey_to_params(eckey, &ptype, &pval)) {
ECerror(EC_R_DECODE_ERROR);
goto err;
}
/* PKCS#11 12.11: don't include parameters in the SEC1 private key. */
EC_KEY_set_enc_flags(eckey, flags | EC_PKEY_NO_PARAMETERS);
if ((key_len = i2d_ECPrivateKey(eckey, &key)) <= 0) {
ECerror(ERR_R_EC_LIB);
key_len = 0;
goto err;
}
if ((aobj = OBJ_nid2obj(NID_X9_62_id_ecPublicKey)) == NULL)
goto err;
if (!PKCS8_pkey_set0(p8, aobj, 0, ptype, pval, key, key_len))
goto err;
pval = NULL;
key = NULL;
key_len = 0;
ret = 1;
err:
eckey_param_free(ptype, pval);
freezero(key, key_len);
EC_KEY_set_enc_flags(eckey, flags);
return ret;
}
static int
ec_size(const EVP_PKEY *pkey)
{
return ECDSA_size(pkey->pkey.ec);
}
static int
ec_bits(const EVP_PKEY *pkey)
{
const EC_GROUP *group;
if ((group = EC_KEY_get0_group(pkey->pkey.ec)) == NULL)
return 0;
return EC_GROUP_order_bits(group);
}
static int
ec_security_bits(const EVP_PKEY *pkey)
{
int ecbits = ec_bits(pkey);
if (ecbits >= 512)
return 256;
if (ecbits >= 384)
return 192;
if (ecbits >= 256)
return 128;
if (ecbits >= 224)
return 112;
if (ecbits >= 160)
return 80;
return ecbits / 2;
}
static int
ec_missing_parameters(const EVP_PKEY *pkey)
{
if (EC_KEY_get0_group(pkey->pkey.ec) == NULL)
return 1;
return 0;
}
static int
ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
{
return EC_KEY_set_group(to->pkey.ec, EC_KEY_get0_group(from->pkey.ec));
}
static int
ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
{
const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec);
const EC_GROUP *group_b = EC_KEY_get0_group(b->pkey.ec);
if (EC_GROUP_cmp(group_a, group_b, NULL))
return 0;
else
return 1;
}
static void
ec_free(EVP_PKEY *pkey)
{
EC_KEY_free(pkey->pkey.ec);
}
static int
do_EC_KEY_print(BIO *bp, const EC_KEY *x, int off, int ktype)
{
const char *ecstr;
int ret = 0, reason = ERR_R_BIO_LIB;
BIGNUM *pub_key = NULL;
BN_CTX *ctx = NULL;
const EC_GROUP *group;
const EC_POINT *public_key;
const BIGNUM *priv_key;
if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL) {
reason = ERR_R_PASSED_NULL_PARAMETER;
goto err;
}
ctx = BN_CTX_new();
if (ctx == NULL) {
reason = ERR_R_MALLOC_FAILURE;
goto err;
}
if (ktype > 0) {
public_key = EC_KEY_get0_public_key(x);
if (public_key != NULL) {
if ((pub_key = EC_POINT_point2bn(group, public_key,
EC_KEY_get_conv_form(x), NULL, ctx)) == NULL) {
reason = ERR_R_EC_LIB;
goto err;
}
}
}
if (ktype == 2) {
priv_key = EC_KEY_get0_private_key(x);
} else
priv_key = NULL;
if (ktype == 2)
ecstr = "Private-Key";
else if (ktype == 1)
ecstr = "Public-Key";
else
ecstr = "ECDSA-Parameters";
if (!BIO_indent(bp, off, 128))
goto err;
if (BIO_printf(bp, "%s: (%d bit)\n", ecstr,
EC_GROUP_order_bits(group)) <= 0)
goto err;
if (!bn_printf(bp, priv_key, off, "priv:"))
goto err;
if (!bn_printf(bp, pub_key, off, "pub: "))
goto err;
if (!ECPKParameters_print(bp, group, off))
goto err;
ret = 1;
err:
if (!ret)
ECerror(reason);
BN_free(pub_key);
BN_CTX_free(ctx);
return (ret);
}
static int
eckey_param_decode(EVP_PKEY *pkey, const unsigned char **param, int param_len)
{
EC_KEY *eckey;
int ret = 0;
if ((eckey = d2i_ECParameters(NULL, param, param_len)) == NULL)
goto err;
if (!EVP_PKEY_assign_EC_KEY(pkey, eckey))
goto err;
eckey = NULL;
ret = 1;
err:
EC_KEY_free(eckey);
return ret;
}
static int
eckey_param_encode(const EVP_PKEY *pkey, unsigned char **param)
{
return i2d_ECParameters(pkey->pkey.ec, param);
}
static int
eckey_param_print(BIO *bp, const EVP_PKEY *pkey, int indent, ASN1_PCTX *ctx)
{
return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 0);
}
static int
eckey_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent, ASN1_PCTX *ctx)
{
return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 1);
}
static int
eckey_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent, ASN1_PCTX *ctx)
{
return do_EC_KEY_print(bp, pkey->pkey.ec, indent, 2);
}
static int
old_ec_priv_decode(EVP_PKEY *pkey, const unsigned char **priv, int priv_len)
{
EC_KEY *eckey;
int ret = 0;
if ((eckey = d2i_ECPrivateKey(NULL, priv, priv_len)) == NULL)
goto err;
if (!EVP_PKEY_assign_EC_KEY(pkey, eckey))
goto err;
eckey = NULL;
ret = 1;
err:
EC_KEY_free(eckey);
return ret;
}
static int
old_ec_priv_encode(const EVP_PKEY *pkey, unsigned char **priv)
{
return i2d_ECPrivateKey(pkey->pkey.ec, priv);
}
static int
ec_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
{
switch (op) {
case ASN1_PKEY_CTRL_PKCS7_SIGN:
if (arg1 == 0) {
int snid, hnid;
X509_ALGOR *alg1, *alg2;
PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2);
if (alg1 == NULL || alg1->algorithm == NULL)
return -1;
hnid = OBJ_obj2nid(alg1->algorithm);
if (hnid == NID_undef)
return -1;
if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
return -1;
if (!X509_ALGOR_set0_by_nid(alg2, snid, V_ASN1_UNDEF,
NULL))
return -1;
}
return 1;
#ifndef OPENSSL_NO_CMS
case ASN1_PKEY_CTRL_CMS_SIGN:
if (arg1 == 0) {
X509_ALGOR *alg1, *alg2;
int snid, hnid;
CMS_SignerInfo_get0_algs(arg2, NULL, NULL, &alg1, &alg2);
if (alg1 == NULL || alg1->algorithm == NULL)
return -1;
hnid = OBJ_obj2nid(alg1->algorithm);
if (hnid == NID_undef)
return -1;
if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
return -1;
if (!X509_ALGOR_set0_by_nid(alg2, snid, V_ASN1_UNDEF,
NULL))
return -1;
}
return 1;
case ASN1_PKEY_CTRL_CMS_ENVELOPE:
if (arg1 == 0)
return ecdh_cms_encrypt(arg2);
else if (arg1 == 1)
return ecdh_cms_decrypt(arg2);
return -2;
case ASN1_PKEY_CTRL_CMS_RI_TYPE:
*(int *)arg2 = CMS_RECIPINFO_AGREE;
return 1;
#endif
case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
*(int *) arg2 = NID_sha1;
return 2;
default:
return -2;
}
}
static int
ec_pkey_check(const EVP_PKEY *pkey)
{
EC_KEY *eckey = pkey->pkey.ec;
if (eckey->priv_key == NULL) {
ECerror(EC_R_MISSING_PRIVATE_KEY);
return 0;
}
return EC_KEY_check_key(eckey);
}
static int
ec_pkey_public_check(const EVP_PKEY *pkey)
{
EC_KEY *eckey = pkey->pkey.ec;
/* This also checks the private key, but oh, well... */
return EC_KEY_check_key(eckey);
}
static int
ec_pkey_param_check(const EVP_PKEY *pkey)
{
EC_KEY *eckey = pkey->pkey.ec;
if (eckey->group == NULL) {
ECerror(EC_R_MISSING_PARAMETERS);
return 0;
}
return EC_GROUP_check(eckey->group, NULL);
}
#ifndef OPENSSL_NO_CMS
static int
ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx, X509_ALGOR *alg,
ASN1_BIT_STRING *pubkey)
{
const ASN1_OBJECT *aoid;
int atype;
const void *aval;
int rv = 0;
EVP_PKEY *pkpeer = NULL;
EC_KEY *ecpeer = NULL;
const unsigned char *p;
int plen;
X509_ALGOR_get0(&aoid, &atype, &aval, alg);
if (OBJ_obj2nid(aoid) != NID_X9_62_id_ecPublicKey)
goto err;
/* If absent parameters get group from main key */
if (atype == V_ASN1_UNDEF || atype == V_ASN1_NULL) {
const EC_GROUP *grp;
EVP_PKEY *pk;
pk = EVP_PKEY_CTX_get0_pkey(pctx);
if (!pk)
goto err;
grp = EC_KEY_get0_group(pk->pkey.ec);
ecpeer = EC_KEY_new();
if (ecpeer == NULL)
goto err;
if (!EC_KEY_set_group(ecpeer, grp))
goto err;
} else {
if (!eckey_from_params(atype, aval, &ecpeer))
goto err;
}
/* We have parameters now set public key */
plen = ASN1_STRING_length(pubkey);
p = ASN1_STRING_get0_data(pubkey);
if (!p || !plen)
goto err;
if (!o2i_ECPublicKey(&ecpeer, &p, plen))
goto err;
pkpeer = EVP_PKEY_new();
if (pkpeer == NULL)
goto err;
EVP_PKEY_set1_EC_KEY(pkpeer, ecpeer);
if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
rv = 1;
err:
EC_KEY_free(ecpeer);
EVP_PKEY_free(pkpeer);
return rv;
}
/* Set KDF parameters based on KDF NID */
static int
ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid)
{
int kdf_nid, kdfmd_nid, cofactor;
const EVP_MD *kdf_md;
if (eckdf_nid == NID_undef)
return 0;
/* Lookup KDF type, cofactor mode and digest */
if (!OBJ_find_sigid_algs(eckdf_nid, &kdfmd_nid, &kdf_nid))
return 0;
if (kdf_nid == NID_dh_std_kdf)
cofactor = 0;
else if (kdf_nid == NID_dh_cofactor_kdf)
cofactor = 1;
else
return 0;
if (EVP_PKEY_CTX_set_ecdh_cofactor_mode(pctx, cofactor) <= 0)
return 0;
if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, EVP_PKEY_ECDH_KDF_X9_63) <= 0)
return 0;
kdf_md = EVP_get_digestbynid(kdfmd_nid);
if (!kdf_md)
return 0;
if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
return 0;
return 1;
}
static int
ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
{
X509_ALGOR *alg, *kekalg = NULL;
ASN1_OCTET_STRING *ukm;
const unsigned char *p;
unsigned char *der = NULL;
int plen, keylen;
const EVP_CIPHER *kekcipher;
EVP_CIPHER_CTX *kekctx;
int rv = 0;
if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
return 0;
if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) {
ECerror(EC_R_KDF_PARAMETER_ERROR);
return 0;
}
if (alg->parameter->type != V_ASN1_SEQUENCE)
return 0;
p = alg->parameter->value.sequence->data;
plen = alg->parameter->value.sequence->length;
kekalg = d2i_X509_ALGOR(NULL, &p, plen);
if (!kekalg)
goto err;
kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
if (!kekctx)
goto err;
kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
goto err;
if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
goto err;
if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
goto err;
keylen = EVP_CIPHER_CTX_key_length(kekctx);
if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
goto err;
plen = CMS_SharedInfo_encode(&der, kekalg, ukm, keylen);
if (plen <= 0)
goto err;
if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
goto err;
der = NULL;
rv = 1;
err:
X509_ALGOR_free(kekalg);
free(der);
return rv;
}
static int
ecdh_cms_decrypt(CMS_RecipientInfo *ri)
{
EVP_PKEY_CTX *pctx;
pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
if (!pctx)
return 0;
/* See if we need to set peer key */
if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
X509_ALGOR *alg;
ASN1_BIT_STRING *pubkey;
if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
NULL, NULL, NULL))
return 0;
if (!alg || !pubkey)
return 0;
if (!ecdh_cms_set_peerkey(pctx, alg, pubkey)) {
ECerror(EC_R_PEER_KEY_ERROR);
return 0;
}
}
/* Set ECDH derivation parameters and initialise unwrap context */
if (!ecdh_cms_set_shared_info(pctx, ri)) {
ECerror(EC_R_SHARED_INFO_ERROR);
return 0;
}
return 1;
}
static int
ecdh_cms_encrypt(CMS_RecipientInfo *ri)
{
EVP_PKEY_CTX *pctx;
EVP_PKEY *pkey;
EVP_CIPHER_CTX *ctx;
int keylen;
X509_ALGOR *talg, *wrap_alg = NULL;
const ASN1_OBJECT *aoid;
ASN1_BIT_STRING *pubkey;
ASN1_STRING *wrap_str;
ASN1_OCTET_STRING *ukm;
unsigned char *penc = NULL;
int penclen;
int ecdh_nid, kdf_type, kdf_nid, wrap_nid;
const EVP_MD *kdf_md;
int rv = 0;
pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
if (!pctx)
return 0;
/* Get ephemeral key */
pkey = EVP_PKEY_CTX_get0_pkey(pctx);
if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
NULL, NULL, NULL))
goto err;
X509_ALGOR_get0(&aoid, NULL, NULL, talg);
/* Is everything uninitialised? */
if (aoid == OBJ_nid2obj(NID_undef)) {
EC_KEY *eckey = pkey->pkey.ec;
unsigned char *p;
/* Set the key */
penclen = i2o_ECPublicKey(eckey, NULL);
if (penclen <= 0)
goto err;
penc = malloc(penclen);
if (penc == NULL)
goto err;
p = penc;
penclen = i2o_ECPublicKey(eckey, &p);
if (penclen <= 0)
goto err;
ASN1_STRING_set0(pubkey, penc, penclen);
if (!asn1_abs_set_unused_bits(pubkey, 0))
goto err;
penc = NULL;
X509_ALGOR_set0(talg, OBJ_nid2obj(NID_X9_62_id_ecPublicKey),
V_ASN1_UNDEF, NULL);
}
/* See if custom parameters set */
kdf_type = EVP_PKEY_CTX_get_ecdh_kdf_type(pctx);
if (kdf_type <= 0)
goto err;
if (!EVP_PKEY_CTX_get_ecdh_kdf_md(pctx, &kdf_md))
goto err;
ecdh_nid = EVP_PKEY_CTX_get_ecdh_cofactor_mode(pctx);
if (ecdh_nid < 0)
goto err;
else if (ecdh_nid == 0)
ecdh_nid = NID_dh_std_kdf;
else if (ecdh_nid == 1)
ecdh_nid = NID_dh_cofactor_kdf;
if (kdf_type == EVP_PKEY_ECDH_KDF_NONE) {
kdf_type = EVP_PKEY_ECDH_KDF_X9_63;
if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0)
goto err;
} else {
/* Unknown KDF */
goto err;
}
if (kdf_md == NULL) {
/* Fixme later for better MD */
kdf_md = EVP_sha1();
if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
goto err;
}
if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
goto err;
/* Lookup NID for KDF+cofactor+digest */
if (!OBJ_find_sigid_by_algs(&kdf_nid, EVP_MD_type(kdf_md), ecdh_nid))
goto err;
/* Get wrap NID */
ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
wrap_nid = EVP_CIPHER_CTX_type(ctx);
keylen = EVP_CIPHER_CTX_key_length(ctx);
/* Package wrap algorithm in an AlgorithmIdentifier */
wrap_alg = X509_ALGOR_new();
if (wrap_alg == NULL)
goto err;
wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
wrap_alg->parameter = ASN1_TYPE_new();
if (wrap_alg->parameter == NULL)
goto err;
if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
goto err;
if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
ASN1_TYPE_free(wrap_alg->parameter);
wrap_alg->parameter = NULL;
}
if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
goto err;
penclen = CMS_SharedInfo_encode(&penc, wrap_alg, ukm, keylen);
if (penclen <= 0)
goto err;
if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, penc, penclen) <= 0)
goto err;
penc = NULL;
/*
* Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
* of another AlgorithmIdentifier.
*/
penclen = i2d_X509_ALGOR(wrap_alg, &penc);
if (penclen <= 0)
goto err;
wrap_str = ASN1_STRING_new();
if (wrap_str == NULL)
goto err;
ASN1_STRING_set0(wrap_str, penc, penclen);
penc = NULL;
X509_ALGOR_set0(talg, OBJ_nid2obj(kdf_nid), V_ASN1_SEQUENCE, wrap_str);
rv = 1;
err:
free(penc);
X509_ALGOR_free(wrap_alg);
return rv;
}
#endif
const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = {
.base_method = &eckey_asn1_meth,
.pkey_id = EVP_PKEY_EC,
.pem_str = "EC",
.info = "OpenSSL EC algorithm",
.pub_decode = eckey_pub_decode,
.pub_encode = eckey_pub_encode,
.pub_cmp = eckey_pub_cmp,
.pub_print = eckey_pub_print,
.priv_decode = eckey_priv_decode,
.priv_encode = eckey_priv_encode,
.priv_print = eckey_priv_print,
.pkey_size = ec_size,
.pkey_bits = ec_bits,
.pkey_security_bits = ec_security_bits,
.param_decode = eckey_param_decode,
.param_encode = eckey_param_encode,
.param_missing = ec_missing_parameters,
.param_copy = ec_copy_parameters,
.param_cmp = ec_cmp_parameters,
.param_print = eckey_param_print,
.pkey_free = ec_free,
.pkey_ctrl = ec_pkey_ctrl,
.old_priv_decode = old_ec_priv_decode,
.old_priv_encode = old_ec_priv_encode,
.pkey_check = ec_pkey_check,
.pkey_public_check = ec_pkey_public_check,
.pkey_param_check = ec_pkey_param_check,
};
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