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openssl/crypto/ec/ec_ameth.c

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/*
* Copyright 2006-2020 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/x509.h>
#include <openssl/ec.h>
#include <openssl/bn.h>
#include <openssl/cms.h>
#include <openssl/asn1t.h>
#include "crypto/asn1.h"
#include "crypto/evp.h"
#include "ec_local.h"
#ifndef OPENSSL_NO_CMS
static int ecdh_cms_decrypt(CMS_RecipientInfo *ri);
static int ecdh_cms_encrypt(CMS_RecipientInfo *ri);
#endif
static int eckey_param2type(int *pptype, void **ppval, const EC_KEY *ec_key)
{
const EC_GROUP *group;
int nid;
if (ec_key == NULL || (group = EC_KEY_get0_group(ec_key)) == NULL) {
ECerr(EC_F_ECKEY_PARAM2TYPE, EC_R_MISSING_PARAMETERS);
return 0;
}
if (EC_GROUP_get_asn1_flag(group)
&& (nid = EC_GROUP_get_curve_name(group)))
/* we have a 'named curve' => just set the OID */
{
ASN1_OBJECT *asn1obj = OBJ_nid2obj(nid);
if (asn1obj == NULL || OBJ_length(asn1obj) == 0) {
ASN1_OBJECT_free(asn1obj);
ECerr(EC_F_ECKEY_PARAM2TYPE, EC_R_MISSING_OID);
return 0;
}
*ppval = asn1obj;
*pptype = V_ASN1_OBJECT;
} else { /* explicit parameters */
ASN1_STRING *pstr = NULL;
pstr = ASN1_STRING_new();
if (pstr == NULL)
return 0;
/*
* The cast in the following line is intentional as the
* `i2d_ECParameters` signature can't be constified (see discussion at
* https://github.com/openssl/openssl/pull/9347 where related and
* required constification backports were rejected).
*
* This cast should be safe anyway, because we can expect
* `i2d_ECParameters()` to treat the first argument as if it was const.
*/
pstr->length = i2d_ECParameters((EC_KEY *)ec_key, &pstr->data);
if (pstr->length <= 0) {
ASN1_STRING_free(pstr);
ECerr(EC_F_ECKEY_PARAM2TYPE, ERR_R_EC_LIB);
return 0;
}
*ppval = pstr;
*pptype = V_ASN1_SEQUENCE;
}
return 1;
}
static int eckey_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
{
const EC_KEY *ec_key = pkey->pkey.ec;
void *pval = NULL;
int ptype;
unsigned char *penc = NULL, *p;
int penclen;
if (!eckey_param2type(&ptype, &pval, ec_key)) {
ECerr(EC_F_ECKEY_PUB_ENCODE, ERR_R_EC_LIB);
return 0;
}
penclen = i2o_ECPublicKey(ec_key, NULL);
if (penclen <= 0)
goto err;
penc = OPENSSL_malloc(penclen);
if (penc == NULL)
goto err;
p = penc;
penclen = i2o_ECPublicKey(ec_key, &p);
if (penclen <= 0)
goto err;
if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(EVP_PKEY_EC),
ptype, pval, penc, penclen))
return 1;
err:
if (ptype == V_ASN1_OBJECT)
ASN1_OBJECT_free(pval);
else
ASN1_STRING_free(pval);
OPENSSL_free(penc);
return 0;
}
static EC_KEY *eckey_type2param(int ptype, const void *pval)
{
EC_KEY *eckey = NULL;
EC_GROUP *group = NULL;
if (ptype == V_ASN1_SEQUENCE) {
const ASN1_STRING *pstr = pval;
const unsigned char *pm = pstr->data;
int pmlen = pstr->length;
if ((eckey = d2i_ECParameters(NULL, &pm, pmlen)) == NULL) {
ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
goto ecerr;
}
} else if (ptype == V_ASN1_OBJECT) {
const ASN1_OBJECT *poid = pval;
/*
* type == V_ASN1_OBJECT => the parameters are given by an asn1 OID
*/
if ((eckey = EC_KEY_new()) == NULL) {
ECerr(EC_F_ECKEY_TYPE2PARAM, ERR_R_MALLOC_FAILURE);
goto ecerr;
}
group = EC_GROUP_new_by_curve_name(OBJ_obj2nid(poid));
if (group == NULL)
goto ecerr;
EC_GROUP_set_asn1_flag(group, OPENSSL_EC_NAMED_CURVE);
if (EC_KEY_set_group(eckey, group) == 0)
goto ecerr;
EC_GROUP_free(group);
} else {
ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
goto ecerr;
}
return eckey;
ecerr:
EC_KEY_free(eckey);
EC_GROUP_free(group);
return NULL;
}
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;
if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
return 0;
X509_ALGOR_get0(NULL, &ptype, &pval, palg);
eckey = eckey_type2param(ptype, pval);
if (!eckey) {
ECerr(EC_F_ECKEY_PUB_DECODE, ERR_R_EC_LIB);
return 0;
}
/* We have parameters now set public key */
if (!o2i_ECPublicKey(&eckey, &p, pklen)) {
ECerr(EC_F_ECKEY_PUB_DECODE, EC_R_DECODE_ERROR);
goto ecerr;
}
EVP_PKEY_assign_EC_KEY(pkey, eckey);
return 1;
ecerr:
EC_KEY_free(eckey);
return 0;
}
static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
{
int r;
const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec);
const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec),
*pb = EC_KEY_get0_public_key(b->pkey.ec);
if (group == NULL || pa == NULL || pb == NULL)
return -2;
r = EC_POINT_cmp(group, pa, pb, NULL);
if (r == 0)
return 1;
if (r == 1)
return 0;
return -2;
}
static int eckey_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
{
const unsigned char *p = NULL;
const void *pval;
int ptype, pklen;
EC_KEY *eckey = NULL;
const X509_ALGOR *palg;
if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
return 0;
X509_ALGOR_get0(NULL, &ptype, &pval, palg);
eckey = eckey_type2param(ptype, pval);
if (!eckey)
goto ecliberr;
/* We have parameters now set private key */
if (!d2i_ECPrivateKey(&eckey, &p, pklen)) {
ECerr(EC_F_ECKEY_PRIV_DECODE, EC_R_DECODE_ERROR);
goto ecerr;
}
EVP_PKEY_assign_EC_KEY(pkey, eckey);
return 1;
ecliberr:
ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
ecerr:
EC_KEY_free(eckey);
return 0;
}
static int eckey_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
{
EC_KEY ec_key = *(pkey->pkey.ec);
unsigned char *ep, *p;
int eplen, ptype;
void *pval;
unsigned int old_flags;
if (!eckey_param2type(&ptype, &pval, &ec_key)) {
ECerr(EC_F_ECKEY_PRIV_ENCODE, EC_R_DECODE_ERROR);
return 0;
}
/* set the private key */
/*
* do not include the parameters in the SEC1 private key see PKCS#11
* 12.11
*/
old_flags = EC_KEY_get_enc_flags(&ec_key);
EC_KEY_set_enc_flags(&ec_key, old_flags | EC_PKEY_NO_PARAMETERS);
eplen = i2d_ECPrivateKey(&ec_key, NULL);
if (!eplen) {
ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
return 0;
}
ep = OPENSSL_malloc(eplen);
if (ep == NULL) {
ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
return 0;
}
p = ep;
if (!i2d_ECPrivateKey(&ec_key, &p)) {
OPENSSL_free(ep);
ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
return 0;
}
if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0,
ptype, pval, ep, eplen)) {
OPENSSL_free(ep);
return 0;
}
return 1;
}
static int int_ec_size(const EVP_PKEY *pkey)
{
return ECDSA_size(pkey->pkey.ec);
}
static int ec_bits(const EVP_PKEY *pkey)
{
return EC_GROUP_order_bits(EC_KEY_get0_group(pkey->pkey.ec));
}
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 (pkey->pkey.ec == NULL || EC_KEY_get0_group(pkey->pkey.ec) == NULL)
return 1;
return 0;
}
static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
{
EC_GROUP *group = EC_GROUP_dup(EC_KEY_get0_group(from->pkey.ec));
if (group == NULL)
return 0;
if (to->pkey.ec == NULL) {
to->pkey.ec = EC_KEY_new();
if (to->pkey.ec == NULL)
goto err;
}
if (EC_KEY_set_group(to->pkey.ec, group) == 0)
goto err;
EC_GROUP_free(group);
return 1;
err:
EC_GROUP_free(group);
return 0;
}
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),
*group_b = EC_KEY_get0_group(b->pkey.ec);
if (group_a == NULL || group_b == NULL)
return -2;
if (EC_GROUP_cmp(group_a, group_b, NULL))
return 0;
else
return 1;
}
static void int_ec_free(EVP_PKEY *pkey)
{
EC_KEY_free(pkey->pkey.ec);
}
typedef enum {
EC_KEY_PRINT_PRIVATE,
EC_KEY_PRINT_PUBLIC,
EC_KEY_PRINT_PARAM
} ec_print_t;
static int do_EC_KEY_print(BIO *bp, const EC_KEY *x, int off, ec_print_t ktype)
{
const char *ecstr;
unsigned char *priv = NULL, *pub = NULL;
size_t privlen = 0, publen = 0;
int ret = 0;
const EC_GROUP *group;
if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL) {
ECerr(EC_F_DO_EC_KEY_PRINT, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
if (ktype != EC_KEY_PRINT_PARAM && EC_KEY_get0_public_key(x) != NULL) {
publen = EC_KEY_key2buf(x, EC_KEY_get_conv_form(x), &pub, NULL);
if (publen == 0)
goto err;
}
if (ktype == EC_KEY_PRINT_PRIVATE && EC_KEY_get0_private_key(x) != NULL) {
privlen = EC_KEY_priv2buf(x, &priv);
if (privlen == 0)
goto err;
}
if (ktype == EC_KEY_PRINT_PRIVATE)
ecstr = "Private-Key";
else if (ktype == EC_KEY_PRINT_PUBLIC)
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 (privlen != 0) {
if (BIO_printf(bp, "%*spriv:\n", off, "") <= 0)
goto err;
if (ASN1_buf_print(bp, priv, privlen, off + 4) == 0)
goto err;
}
if (publen != 0) {
if (BIO_printf(bp, "%*spub:\n", off, "") <= 0)
goto err;
if (ASN1_buf_print(bp, pub, publen, off + 4) == 0)
goto err;
}
if (!ECPKParameters_print(bp, group, off))
goto err;
ret = 1;
err:
if (!ret)
ECerr(EC_F_DO_EC_KEY_PRINT, ERR_R_EC_LIB);
OPENSSL_clear_free(priv, privlen);
OPENSSL_free(pub);
return ret;
}
static int eckey_param_decode(EVP_PKEY *pkey,
const unsigned char **pder, int derlen)
{
EC_KEY *eckey;
if ((eckey = d2i_ECParameters(NULL, pder, derlen)) == NULL) {
ECerr(EC_F_ECKEY_PARAM_DECODE, ERR_R_EC_LIB);
return 0;
}
EVP_PKEY_assign_EC_KEY(pkey, eckey);
return 1;
}
static int eckey_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
{
return i2d_ECParameters(pkey->pkey.ec, pder);
}
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, EC_KEY_PRINT_PARAM);
}
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, EC_KEY_PRINT_PUBLIC);
}
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, EC_KEY_PRINT_PRIVATE);
}
static int old_ec_priv_decode(EVP_PKEY *pkey,
const unsigned char **pder, int derlen)
{
EC_KEY *ec;
if ((ec = d2i_ECPrivateKey(NULL, pder, derlen)) == NULL) {
ECerr(EC_F_OLD_EC_PRIV_DECODE, EC_R_DECODE_ERROR);
return 0;
}
EVP_PKEY_assign_EC_KEY(pkey, ec);
return 1;
}
static int old_ec_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
{
return i2d_ECPrivateKey(pkey->pkey.ec, pder);
}
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;
X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
}
return 1;
#ifndef OPENSSL_NO_CMS
case ASN1_PKEY_CTRL_CMS_SIGN:
if (arg1 == 0) {
int snid, hnid;
X509_ALGOR *alg1, *alg2;
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;
X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
}
return 1;
case ASN1_PKEY_CTRL_CMS_ENVELOPE:
if (arg1 == 1)
return ecdh_cms_decrypt(arg2);
else if (arg1 == 0)
return ecdh_cms_encrypt(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:
if (EVP_PKEY_id(pkey) == EVP_PKEY_SM2) {
/* For SM2, the only valid digest-alg is SM3 */
*(int *)arg2 = NID_sm3;
} else {
*(int *)arg2 = NID_sha256;
}
return 1;
case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
return EC_KEY_oct2key(EVP_PKEY_get0_EC_KEY(pkey), arg2, arg1, NULL);
case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
return EC_KEY_key2buf(EVP_PKEY_get0_EC_KEY(pkey),
POINT_CONVERSION_UNCOMPRESSED, arg2, NULL);
default:
return -2;
}
}
static int ec_pkey_check(const EVP_PKEY *pkey)
{
EC_KEY *eckey = pkey->pkey.ec;
/* stay consistent to what EVP_PKEY_check demands */
if (eckey->priv_key == NULL) {
ECerr(EC_F_EC_PKEY_CHECK, 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;
/*
* Note: it unnecessary to check eckey->pub_key here since
* it will be checked in EC_KEY_check_key(). In fact, the
* EC_KEY_check_key() mainly checks the public key, and checks
* the private key optionally (only if there is one). So if
* someone passes a whole EC key (public + private), this
* will also work...
*/
return EC_KEY_check_key(eckey);
}
static int ec_pkey_param_check(const EVP_PKEY *pkey)
{
EC_KEY *eckey = pkey->pkey.ec;
/* stay consistent to what EVP_PKEY_check demands */
if (eckey->group == NULL) {
ECerr(EC_F_EC_PKEY_PARAM_CHECK, EC_R_MISSING_PARAMETERS);
return 0;
}
return EC_GROUP_check(eckey->group, NULL);
}
const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = {
EVP_PKEY_EC,
EVP_PKEY_EC,
0,
"EC",
"OpenSSL EC algorithm",
eckey_pub_decode,
eckey_pub_encode,
eckey_pub_cmp,
eckey_pub_print,
eckey_priv_decode,
eckey_priv_encode,
eckey_priv_print,
int_ec_size,
ec_bits,
ec_security_bits,
eckey_param_decode,
eckey_param_encode,
ec_missing_parameters,
ec_copy_parameters,
ec_cmp_parameters,
eckey_param_print,
0,
int_ec_free,
ec_pkey_ctrl,
old_ec_priv_decode,
old_ec_priv_encode,
0, 0, 0,
ec_pkey_check,
ec_pkey_public_check,
ec_pkey_param_check
};
#if !defined(OPENSSL_NO_SM2)
const EVP_PKEY_ASN1_METHOD sm2_asn1_meth = {
EVP_PKEY_SM2,
EVP_PKEY_EC,
ASN1_PKEY_ALIAS
};
#endif
int EC_KEY_print(BIO *bp, const EC_KEY *x, int off)
{
int private = EC_KEY_get0_private_key(x) != NULL;
return do_EC_KEY_print(bp, x, off,
private ? EC_KEY_PRINT_PRIVATE : EC_KEY_PRINT_PUBLIC);
}
int ECParameters_print(BIO *bp, const EC_KEY *x)
{
return do_EC_KEY_print(bp, x, 4, EC_KEY_PRINT_PARAM);
}
#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 {
ecpeer = eckey_type2param(atype, aval);
if (!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)
{
int rv = 0;
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;
if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
return 0;
if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) {
ECerr(EC_F_ECDH_CMS_SET_SHARED_INFO, 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)
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);
OPENSSL_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)) {
ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_PEER_KEY_ERROR);
return 0;
}
}
/* Set ECDH derivation parameters and initialise unwrap context */
if (!ecdh_cms_set_shared_info(pctx, ri)) {
ECerr(EC_F_ECDH_CMS_DECRYPT, 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 rv = 0;
int ecdh_nid, kdf_type, kdf_nid, wrap_nid;
const EVP_MD *kdf_md;
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;
/* Set the key */
unsigned char *p;
penclen = i2o_ECPublicKey(eckey, NULL);
if (penclen <= 0)
goto err;
penc = OPENSSL_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);
pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
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)
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 (!penc || !penclen)
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:
OPENSSL_free(penc);
X509_ALGOR_free(wrap_alg);
return rv;
}
#endif
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