ecx_backend.c
/*
* Copyright 2020-2023 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (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 <string.h>
#include <openssl/core_names.h>
#include <openssl/params.h>
#include <openssl/ec.h>
#include <openssl/rand.h>
#include <openssl/err.h>
#ifndef FIPS_MODULE
# include <openssl/x509.h>
#endif
#include "crypto/ecx.h"
#include "ecx_backend.h"
/*
* The intention with the "backend" source file is to offer backend support
* for legacy backends (EVP_PKEY_ASN1_METHOD and EVP_PKEY_METHOD) and provider
* implementations alike.
*/
int ossl_ecx_public_from_private(ECX_KEY *key)
{
switch (key->type) {
case ECX_KEY_TYPE_X25519:
ossl_x25519_public_from_private(key->pubkey, key->privkey);
break;
case ECX_KEY_TYPE_ED25519:
if (!ossl_ed25519_public_from_private(key->libctx, key->pubkey,
key->privkey, key->propq)) {
ERR_raise(ERR_LIB_EC, EC_R_FAILED_MAKING_PUBLIC_KEY);
return 0;
}
break;
case ECX_KEY_TYPE_X448:
ossl_x448_public_from_private(key->pubkey, key->privkey);
break;
case ECX_KEY_TYPE_ED448:
if (!ossl_ed448_public_from_private(key->libctx, key->pubkey,
key->privkey, key->propq)) {
ERR_raise(ERR_LIB_EC, EC_R_FAILED_MAKING_PUBLIC_KEY);
return 0;
}
break;
}
return 1;
}
int ossl_ecx_key_fromdata(ECX_KEY *ecx, const OSSL_PARAM params[],
int include_private)
{
size_t privkeylen = 0, pubkeylen = 0;
const OSSL_PARAM *param_priv_key = NULL, *param_pub_key;
unsigned char *pubkey;
if (ecx == NULL)
return 0;
param_pub_key = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PUB_KEY);
if (include_private)
param_priv_key =
OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PRIV_KEY);
if (param_pub_key == NULL && param_priv_key == NULL)
return 0;
if (param_priv_key != NULL) {
if (!OSSL_PARAM_get_octet_string(param_priv_key,
(void **)&ecx->privkey, ecx->keylen,
&privkeylen))
return 0;
if (privkeylen != ecx->keylen) {
/*
* Invalid key length. We will clear what we've received now. We
* can't leave it to ossl_ecx_key_free() because that will call
* OPENSSL_secure_clear_free() and assume the correct key length
*/
OPENSSL_secure_clear_free(ecx->privkey, privkeylen);
ecx->privkey = NULL;
return 0;
}
}
pubkey = ecx->pubkey;
if (param_pub_key != NULL
&& !OSSL_PARAM_get_octet_string(param_pub_key,
(void **)&pubkey,
sizeof(ecx->pubkey), &pubkeylen))
return 0;
if ((param_pub_key != NULL && pubkeylen != ecx->keylen))
return 0;
if (param_pub_key == NULL && !ossl_ecx_public_from_private(ecx))
return 0;
ecx->haspubkey = 1;
return 1;
}
ECX_KEY *ossl_ecx_key_dup(const ECX_KEY *key, int selection)
{
ECX_KEY *ret = OPENSSL_zalloc(sizeof(*ret));
if (ret == NULL)
return NULL;
ret->libctx = key->libctx;
ret->haspubkey = key->haspubkey;
ret->keylen = key->keylen;
ret->type = key->type;
if (!CRYPTO_NEW_REF(&ret->references, 1))
goto err;
if (key->propq != NULL) {
ret->propq = OPENSSL_strdup(key->propq);
if (ret->propq == NULL)
goto err;
}
if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)
memcpy(ret->pubkey, key->pubkey, sizeof(ret->pubkey));
if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0
&& key->privkey != NULL) {
if (ossl_ecx_key_allocate_privkey(ret) == NULL) {
ERR_raise(ERR_LIB_EC, ERR_R_EC_LIB);
goto err;
}
memcpy(ret->privkey, key->privkey, ret->keylen);
}
return ret;
err:
CRYPTO_FREE_REF(&ret->references);
ossl_ecx_key_free(ret);
return NULL;
}
#ifndef FIPS_MODULE
ECX_KEY *ossl_ecx_key_op(const X509_ALGOR *palg,
const unsigned char *p, int plen,
int id, ecx_key_op_t op,
OSSL_LIB_CTX *libctx, const char *propq)
{
ECX_KEY *key = NULL;
unsigned char *privkey, *pubkey;
if (op != KEY_OP_KEYGEN) {
if (palg != NULL) {
int ptype;
/* Algorithm parameters must be absent */
X509_ALGOR_get0(NULL, &ptype, NULL, palg);
if (ptype != V_ASN1_UNDEF) {
ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
return 0;
}
if (id == EVP_PKEY_NONE)
id = OBJ_obj2nid(palg->algorithm);
else if (id != OBJ_obj2nid(palg->algorithm)) {
ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
return 0;
}
}
if (p == NULL || id == EVP_PKEY_NONE || plen != KEYLENID(id)) {
ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
return 0;
}
}
key = ossl_ecx_key_new(libctx, KEYNID2TYPE(id), 1, propq);
if (key == NULL) {
ERR_raise(ERR_LIB_EC, ERR_R_EC_LIB);
return 0;
}
pubkey = key->pubkey;
if (op == KEY_OP_PUBLIC) {
memcpy(pubkey, p, plen);
} else {
privkey = ossl_ecx_key_allocate_privkey(key);
if (privkey == NULL) {
ERR_raise(ERR_LIB_EC, ERR_R_EC_LIB);
goto err;
}
if (op == KEY_OP_KEYGEN) {
if (id != EVP_PKEY_NONE) {
if (RAND_priv_bytes_ex(libctx, privkey, KEYLENID(id), 0) <= 0)
goto err;
if (id == EVP_PKEY_X25519) {
privkey[0] &= 248;
privkey[X25519_KEYLEN - 1] &= 127;
privkey[X25519_KEYLEN - 1] |= 64;
} else if (id == EVP_PKEY_X448) {
privkey[0] &= 252;
privkey[X448_KEYLEN - 1] |= 128;
}
}
} else {
memcpy(privkey, p, KEYLENID(id));
}
if (!ossl_ecx_public_from_private(key)) {
ERR_raise(ERR_LIB_EC, EC_R_FAILED_MAKING_PUBLIC_KEY);
goto err;
}
}
return key;
err:
ossl_ecx_key_free(key);
return NULL;
}
ECX_KEY *ossl_ecx_key_from_pkcs8(const PKCS8_PRIV_KEY_INFO *p8inf,
OSSL_LIB_CTX *libctx, const char *propq)
{
ECX_KEY *ecx = NULL;
const unsigned char *p;
int plen;
ASN1_OCTET_STRING *oct = NULL;
const X509_ALGOR *palg;
if (!PKCS8_pkey_get0(NULL, &p, &plen, &palg, p8inf))
return 0;
oct = d2i_ASN1_OCTET_STRING(NULL, &p, plen);
if (oct == NULL) {
p = NULL;
plen = 0;
} else {
p = ASN1_STRING_get0_data(oct);
plen = ASN1_STRING_length(oct);
}
/*
* EVP_PKEY_NONE means that ecx_key_op() has to figure out the key type
* on its own.
*/
ecx = ossl_ecx_key_op(palg, p, plen, EVP_PKEY_NONE, KEY_OP_PRIVATE,
libctx, propq);
ASN1_OCTET_STRING_free(oct);
return ecx;
}
#endif
