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Mini Shell
Mini Shell
/*
* Copyright 2006-2022 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
*/
/*
* ECDH and ECDSA low level APIs are deprecated for public use, but still ok
* for internal use.
*/
#include "internal/deprecated.h"
#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/x509.h>
#include <openssl/ec.h>
#include <openssl/bn.h>
#include <openssl/asn1t.h>
#include "crypto/asn1.h"
#include "crypto/evp.h"
#include "crypto/x509.h"
#include <openssl/core_names.h>
#include <openssl/param_build.h>
#include "ec_local.h"
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) {
ERR_raise(ERR_LIB_EC, 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) {
ERR_raise(ERR_LIB_EC, 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;
pstr->length = i2d_ECParameters(ec_key, &pstr->data);
if (pstr->length <= 0) {
ASN1_STRING_free(pstr);
ERR_raise(ERR_LIB_EC, 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)) {
ERR_raise(ERR_LIB_EC, 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_SEQUENCE)
ASN1_STRING_free(pval);
OPENSSL_free(penc);
return 0;
}
static int eckey_pub_decode(EVP_PKEY *pkey, const X509_PUBKEY *pubkey)
{
const unsigned char *p = NULL;
int pklen;
EC_KEY *eckey = NULL;
X509_ALGOR *palg;
OSSL_LIB_CTX *libctx = NULL;
const char *propq = NULL;
if (!ossl_x509_PUBKEY_get0_libctx(&libctx, &propq, pubkey)
|| !X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
return 0;
eckey = ossl_ec_key_param_from_x509_algor(palg, libctx, propq);
if (!eckey)
return 0;
/* We have parameters now set public key */
if (!o2i_ECPublicKey(&eckey, &p, pklen)) {
ERR_raise(ERR_LIB_EC, 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_ex(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8,
OSSL_LIB_CTX *libctx, const char *propq)
{
int ret = 0;
EC_KEY *eckey = ossl_ec_key_from_pkcs8(p8, libctx, propq);
if (eckey != NULL) {
ret = 1;
EVP_PKEY_assign_EC_KEY(pkey, eckey);
}
return ret;
}
static int eckey_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
{
EC_KEY ec_key = *(pkey->pkey.ec);
unsigned char *ep = NULL;
int eplen, ptype;
void *pval;
unsigned int old_flags;
if (!eckey_param2type(&ptype, &pval, &ec_key)) {
ERR_raise(ERR_LIB_EC, 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, &ep);
if (eplen <= 0) {
ERR_raise(ERR_LIB_EC, ERR_R_EC_LIB);
goto err;
}
if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0,
ptype, pval, ep, eplen)) {
ERR_raise(ERR_LIB_EC, ERR_R_ASN1_LIB);
OPENSSL_clear_free(ep, eplen);
goto err;
}
return 1;
err:
if (ptype == V_ASN1_SEQUENCE)
ASN1_STRING_free(pval);
return 0;
}
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) {
ERR_raise(ERR_LIB_EC, 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)
ERR_raise(ERR_LIB_EC, 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)
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)
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_DEFAULT_MD_NID:
if (EVP_PKEY_get_id(pkey) == EVP_PKEY_SM2) {
/* For SM2, the only valid digest-alg is SM3 */
*(int *)arg2 = NID_sm3;
return 2; /* Make it mandatory */
}
*(int *)arg2 = NID_sha256;
return 1;
case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
/* We should only be here if we have a legacy key */
if (!ossl_assert(evp_pkey_is_legacy(pkey)))
return 0;
return EC_KEY_oct2key(evp_pkey_get0_EC_KEY_int(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) {
ERR_raise(ERR_LIB_EC, 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) {
ERR_raise(ERR_LIB_EC, EC_R_MISSING_PARAMETERS);
return 0;
}
return EC_GROUP_check(eckey->group, NULL);
}
static
size_t ec_pkey_dirty_cnt(const EVP_PKEY *pkey)
{
return pkey->pkey.ec->dirty_cnt;
}
static
int ec_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
OSSL_FUNC_keymgmt_import_fn *importer,
OSSL_LIB_CTX *libctx, const char *propq)
{
const EC_KEY *eckey = NULL;
const EC_GROUP *ecg = NULL;
unsigned char *pub_key_buf = NULL, *gen_buf = NULL;
size_t pub_key_buflen;
OSSL_PARAM_BLD *tmpl;
OSSL_PARAM *params = NULL;
const BIGNUM *priv_key = NULL;
const EC_POINT *pub_point = NULL;
int selection = 0;
int rv = 0;
BN_CTX *bnctx = NULL;
if (from == NULL
|| (eckey = from->pkey.ec) == NULL
|| (ecg = EC_KEY_get0_group(eckey)) == NULL)
return 0;
tmpl = OSSL_PARAM_BLD_new();
if (tmpl == NULL)
return 0;
/*
* EC_POINT_point2buf() can generate random numbers in some
* implementations so we need to ensure we use the correct libctx.
*/
bnctx = BN_CTX_new_ex(libctx);
if (bnctx == NULL)
goto err;
BN_CTX_start(bnctx);
/* export the domain parameters */
if (!ossl_ec_group_todata(ecg, tmpl, NULL, libctx, propq, bnctx, &gen_buf))
goto err;
selection |= OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS;
priv_key = EC_KEY_get0_private_key(eckey);
pub_point = EC_KEY_get0_public_key(eckey);
if (pub_point != NULL) {
/* convert pub_point to a octet string according to the SECG standard */
point_conversion_form_t format = EC_KEY_get_conv_form(eckey);
if ((pub_key_buflen = EC_POINT_point2buf(ecg, pub_point,
format,
&pub_key_buf, bnctx)) == 0
|| !OSSL_PARAM_BLD_push_octet_string(tmpl,
OSSL_PKEY_PARAM_PUB_KEY,
pub_key_buf,
pub_key_buflen))
goto err;
selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
}
if (priv_key != NULL) {
size_t sz;
int ecbits;
int ecdh_cofactor_mode;
/*
* Key import/export should never leak the bit length of the secret
* scalar in the key.
*
* For this reason, on export we use padded BIGNUMs with fixed length.
*
* When importing we also should make sure that, even if short lived,
* the newly created BIGNUM is marked with the BN_FLG_CONSTTIME flag as
* soon as possible, so that any processing of this BIGNUM might opt for
* constant time implementations in the backend.
*
* Setting the BN_FLG_CONSTTIME flag alone is never enough, we also have
* to preallocate the BIGNUM internal buffer to a fixed public size big
* enough that operations performed during the processing never trigger
* a realloc which would leak the size of the scalar through memory
* accesses.
*
* Fixed Length
* ------------
*
* The order of the large prime subgroup of the curve is our choice for
* a fixed public size, as that is generally the upper bound for
* generating a private key in EC cryptosystems and should fit all valid
* secret scalars.
*
* For padding on export we just use the bit length of the order
* converted to bytes (rounding up).
*
* For preallocating the BIGNUM storage we look at the number of "words"
* required for the internal representation of the order, and we
* preallocate 2 extra "words" in case any of the subsequent processing
* might temporarily overflow the order length.
*/
ecbits = EC_GROUP_order_bits(ecg);
if (ecbits <= 0)
goto err;
sz = (ecbits + 7 ) / 8;
if (!OSSL_PARAM_BLD_push_BN_pad(tmpl,
OSSL_PKEY_PARAM_PRIV_KEY,
priv_key, sz))
goto err;
selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
/*
* The ECDH Cofactor Mode is defined only if the EC_KEY actually
* contains a private key, so we check for the flag and export it only
* in this case.
*/
ecdh_cofactor_mode =
(EC_KEY_get_flags(eckey) & EC_FLAG_COFACTOR_ECDH) ? 1 : 0;
/* Export the ECDH_COFACTOR_MODE parameter */
if (!OSSL_PARAM_BLD_push_int(tmpl,
OSSL_PKEY_PARAM_USE_COFACTOR_ECDH,
ecdh_cofactor_mode))
goto err;
selection |= OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS;
}
params = OSSL_PARAM_BLD_to_param(tmpl);
/* We export, the provider imports */
rv = importer(to_keydata, selection, params);
err:
OSSL_PARAM_BLD_free(tmpl);
OSSL_PARAM_free(params);
OPENSSL_free(pub_key_buf);
OPENSSL_free(gen_buf);
BN_CTX_end(bnctx);
BN_CTX_free(bnctx);
return rv;
}
static int ec_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
{
EVP_PKEY_CTX *pctx = vpctx;
EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
EC_KEY *ec = EC_KEY_new_ex(pctx->libctx, pctx->propquery);
if (ec == NULL) {
ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
return 0;
}
if (!ossl_ec_group_fromdata(ec, params)
|| !ossl_ec_key_otherparams_fromdata(ec, params)
|| !ossl_ec_key_fromdata(ec, params, 1)
|| !EVP_PKEY_assign_EC_KEY(pkey, ec)) {
EC_KEY_free(ec);
return 0;
}
return 1;
}
static int ec_pkey_copy(EVP_PKEY *to, EVP_PKEY *from)
{
EC_KEY *eckey = from->pkey.ec;
EC_KEY *dupkey = NULL;
int ret;
if (eckey != NULL) {
dupkey = EC_KEY_dup(eckey);
if (dupkey == NULL)
return 0;
} else {
/* necessary to properly copy empty SM2 keys */
return EVP_PKEY_set_type(to, from->type);
}
ret = EVP_PKEY_assign_EC_KEY(to, dupkey);
if (!ret)
EC_KEY_free(dupkey);
return ret;
}
const EVP_PKEY_ASN1_METHOD ossl_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,
NULL,
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,
0, /* set_priv_key */
0, /* set_pub_key */
0, /* get_priv_key */
0, /* get_pub_key */
ec_pkey_dirty_cnt,
ec_pkey_export_to,
ec_pkey_import_from,
ec_pkey_copy,
eckey_priv_decode_ex
};
#if !defined(OPENSSL_NO_SM2)
const EVP_PKEY_ASN1_METHOD ossl_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);
}
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