blob: 8cdb5c3e754991c058bbf66eacd33918ea126a73 [file] [log] [blame]
/* Originally written by Bodo Moeller for the OpenSSL project.
* ====================================================================
* Copyright (c) 1998-2005 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
* openssl-core@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).
*
*/
/* ====================================================================
* Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
*
* Portions of the attached software ("Contribution") are developed by
* SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
*
* The Contribution is licensed pursuant to the OpenSSL open source
* license provided above.
*
* The elliptic curve binary polynomial software is originally written by
* Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems
* Laboratories. */
#include <openssl/ec_key.h>
#include <string.h>
#include <openssl/ec.h>
#include <openssl/ecdsa.h>
#include <openssl/engine.h>
#include <openssl/err.h>
#include <openssl/ex_data.h>
#include <openssl/mem.h>
#include <openssl/thread.h>
#include "internal.h"
#include "../delocate.h"
#include "../service_indicator/internal.h"
#include "../../internal.h"
DEFINE_STATIC_EX_DATA_CLASS(g_ec_ex_data_class)
static EC_WRAPPED_SCALAR *ec_wrapped_scalar_new(const EC_GROUP *group) {
EC_WRAPPED_SCALAR *wrapped = OPENSSL_zalloc(sizeof(EC_WRAPPED_SCALAR));
if (wrapped == NULL) {
return NULL;
}
wrapped->bignum.d = wrapped->scalar.words;
wrapped->bignum.width = group->order.N.width;
wrapped->bignum.dmax = group->order.N.width;
wrapped->bignum.flags = BN_FLG_STATIC_DATA;
return wrapped;
}
static void ec_wrapped_scalar_free(EC_WRAPPED_SCALAR *scalar) {
OPENSSL_free(scalar);
}
EC_KEY *EC_KEY_new(void) { return EC_KEY_new_method(NULL); }
EC_KEY *EC_KEY_new_method(const ENGINE *engine) {
EC_KEY *ret = OPENSSL_zalloc(sizeof(EC_KEY));
if (ret == NULL) {
return NULL;
}
if (engine) {
ret->ecdsa_meth = ENGINE_get_ECDSA_method(engine);
}
if (ret->ecdsa_meth) {
METHOD_ref(ret->ecdsa_meth);
}
ret->conv_form = POINT_CONVERSION_UNCOMPRESSED;
ret->references = 1;
CRYPTO_new_ex_data(&ret->ex_data);
if (ret->ecdsa_meth && ret->ecdsa_meth->init && !ret->ecdsa_meth->init(ret)) {
CRYPTO_free_ex_data(g_ec_ex_data_class_bss_get(), ret, &ret->ex_data);
if (ret->ecdsa_meth) {
METHOD_unref(ret->ecdsa_meth);
}
OPENSSL_free(ret);
return NULL;
}
return ret;
}
EC_KEY *EC_KEY_new_by_curve_name(int nid) {
EC_KEY *ret = EC_KEY_new();
if (ret == NULL) {
return NULL;
}
ret->group = EC_GROUP_new_by_curve_name(nid);
if (ret->group == NULL) {
EC_KEY_free(ret);
return NULL;
}
return ret;
}
void EC_KEY_free(EC_KEY *r) {
if (r == NULL) {
return;
}
if (!CRYPTO_refcount_dec_and_test_zero(&r->references)) {
return;
}
if (r->ecdsa_meth) {
if (r->ecdsa_meth->finish) {
r->ecdsa_meth->finish(r);
}
METHOD_unref(r->ecdsa_meth);
}
CRYPTO_free_ex_data(g_ec_ex_data_class_bss_get(), r, &r->ex_data);
EC_GROUP_free(r->group);
EC_POINT_free(r->pub_key);
ec_wrapped_scalar_free(r->priv_key);
OPENSSL_free(r);
}
EC_KEY *EC_KEY_dup(const EC_KEY *src) {
if (src == NULL) {
OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
return NULL;
}
EC_KEY *ret = EC_KEY_new();
if (ret == NULL) {
return NULL;
}
if ((src->group != NULL &&
!EC_KEY_set_group(ret, src->group)) ||
(src->pub_key != NULL &&
!EC_KEY_set_public_key(ret, src->pub_key)) ||
(src->priv_key != NULL &&
!EC_KEY_set_private_key(ret, EC_KEY_get0_private_key(src)))) {
EC_KEY_free(ret);
return NULL;
}
ret->enc_flag = src->enc_flag;
ret->conv_form = src->conv_form;
return ret;
}
int EC_KEY_up_ref(EC_KEY *r) {
CRYPTO_refcount_inc(&r->references);
return 1;
}
int EC_KEY_is_opaque(const EC_KEY *key) {
return key->ecdsa_meth && (key->ecdsa_meth->flags & ECDSA_FLAG_OPAQUE);
}
const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key) { return key->group; }
int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group) {
// If |key| already has a group, it is an error to switch to another one.
if (key->group != NULL) {
if (EC_GROUP_cmp(key->group, group, NULL) != 0) {
OPENSSL_PUT_ERROR(EC, EC_R_GROUP_MISMATCH);
return 0;
}
return 1;
}
assert(key->priv_key == NULL);
assert(key->pub_key == NULL);
EC_GROUP_free(key->group);
key->group = EC_GROUP_dup(group);
return key->group != NULL;
}
const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key) {
return key->priv_key != NULL ? &key->priv_key->bignum : NULL;
}
int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key) {
if (key->group == NULL) {
OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PARAMETERS);
return 0;
}
EC_WRAPPED_SCALAR *scalar = ec_wrapped_scalar_new(key->group);
if (scalar == NULL) {
return 0;
}
if (!ec_bignum_to_scalar(key->group, &scalar->scalar, priv_key) ||
// Zero is not a valid private key, so it is safe to leak the result of
// this comparison.
constant_time_declassify_int(
ec_scalar_is_zero(key->group, &scalar->scalar))) {
OPENSSL_PUT_ERROR(EC, EC_R_INVALID_PRIVATE_KEY);
ec_wrapped_scalar_free(scalar);
return 0;
}
ec_wrapped_scalar_free(key->priv_key);
key->priv_key = scalar;
return 1;
}
const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key) {
return key->pub_key;
}
int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key) {
if (key->group == NULL) {
OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PARAMETERS);
return 0;
}
if (pub_key != NULL && EC_GROUP_cmp(key->group, pub_key->group, NULL) != 0) {
OPENSSL_PUT_ERROR(EC, EC_R_GROUP_MISMATCH);
return 0;
}
EC_POINT_free(key->pub_key);
key->pub_key = EC_POINT_dup(pub_key, key->group);
return (key->pub_key == NULL) ? 0 : 1;
}
unsigned int EC_KEY_get_enc_flags(const EC_KEY *key) { return key->enc_flag; }
void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags) {
key->enc_flag = flags;
}
point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key) {
return key->conv_form;
}
void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform) {
key->conv_form = cform;
}
int EC_KEY_check_key(const EC_KEY *eckey) {
if (!eckey || !eckey->group || !eckey->pub_key) {
OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) {
OPENSSL_PUT_ERROR(EC, EC_R_POINT_AT_INFINITY);
return 0;
}
// Test whether the public key is on the elliptic curve.
if (!EC_POINT_is_on_curve(eckey->group, eckey->pub_key, NULL)) {
OPENSSL_PUT_ERROR(EC, EC_R_POINT_IS_NOT_ON_CURVE);
return 0;
}
// Check the public and private keys match.
//
// NOTE: this is a FIPS pair-wise consistency check for the ECDH case. See SP
// 800-56Ar3, page 36.
if (eckey->priv_key != NULL) {
EC_JACOBIAN point;
if (!ec_point_mul_scalar_base(eckey->group, &point,
&eckey->priv_key->scalar)) {
OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
return 0;
}
// Leaking this comparison only leaks whether |eckey|'s public key was
// correct.
if (!constant_time_declassify_int(ec_GFp_simple_points_equal(
eckey->group, &point, &eckey->pub_key->raw))) {
OPENSSL_PUT_ERROR(EC, EC_R_INVALID_PRIVATE_KEY);
return 0;
}
}
return 1;
}
int EC_KEY_check_fips(const EC_KEY *key) {
int ret = 0;
FIPS_service_indicator_lock_state();
if (EC_KEY_is_opaque(key)) {
// Opaque keys can't be checked.
OPENSSL_PUT_ERROR(EC, EC_R_PUBLIC_KEY_VALIDATION_FAILED);
goto end;
}
if (!EC_KEY_check_key(key)) {
goto end;
}
if (key->priv_key) {
uint8_t data[16] = {0};
ECDSA_SIG *sig = ECDSA_do_sign(data, sizeof(data), key);
if (boringssl_fips_break_test("ECDSA_PWCT")) {
data[0] = ~data[0];
}
int ok = sig != NULL &&
ECDSA_do_verify(data, sizeof(data), sig, key);
ECDSA_SIG_free(sig);
if (!ok) {
OPENSSL_PUT_ERROR(EC, EC_R_PUBLIC_KEY_VALIDATION_FAILED);
goto end;
}
}
ret = 1;
end:
FIPS_service_indicator_unlock_state();
if (ret) {
EC_KEY_keygen_verify_service_indicator(key);
}
return ret;
}
int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, const BIGNUM *x,
const BIGNUM *y) {
EC_POINT *point = NULL;
int ok = 0;
if (!key || !key->group || !x || !y) {
OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
point = EC_POINT_new(key->group);
if (point == NULL ||
!EC_POINT_set_affine_coordinates_GFp(key->group, point, x, y, NULL) ||
!EC_KEY_set_public_key(key, point) ||
!EC_KEY_check_key(key)) {
goto err;
}
ok = 1;
err:
EC_POINT_free(point);
return ok;
}
int EC_KEY_oct2key(EC_KEY *key, const uint8_t *in, size_t len, BN_CTX *ctx) {
if (key->group == NULL) {
OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PARAMETERS);
return 0;
}
EC_POINT *point = EC_POINT_new(key->group);
int ok = point != NULL &&
EC_POINT_oct2point(key->group, point, in, len, ctx) &&
EC_KEY_set_public_key(key, point);
EC_POINT_free(point);
return ok;
}
size_t EC_KEY_key2buf(const EC_KEY *key, point_conversion_form_t form,
uint8_t **out_buf, BN_CTX *ctx) {
if (key == NULL || key->pub_key == NULL || key->group == NULL) {
OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PARAMETERS);
return 0;
}
return EC_POINT_point2buf(key->group, key->pub_key, form, out_buf, ctx);
}
int EC_KEY_oct2priv(EC_KEY *key, const uint8_t *in, size_t len) {
if (key->group == NULL) {
OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PARAMETERS);
return 0;
}
if (len != BN_num_bytes(EC_GROUP_get0_order(key->group))) {
OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR);
return 0;
}
BIGNUM *priv_key = BN_bin2bn(in, len, NULL);
int ok = priv_key != NULL && //
EC_KEY_set_private_key(key, priv_key);
BN_free(priv_key);
return ok;
}
size_t EC_KEY_priv2oct(const EC_KEY *key, uint8_t *out, size_t max_out) {
if (key->group == NULL || key->priv_key == NULL) {
OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PARAMETERS);
return 0;
}
size_t len = BN_num_bytes(EC_GROUP_get0_order(key->group));
if (out == NULL) {
return len;
}
if (max_out < len) {
OPENSSL_PUT_ERROR(EC, EC_R_BUFFER_TOO_SMALL);
return 0;
}
size_t bytes_written;
ec_scalar_to_bytes(key->group, out, &bytes_written, &key->priv_key->scalar);
assert(bytes_written == len);
return len;
}
size_t EC_KEY_priv2buf(const EC_KEY *key, uint8_t **out_buf) {
*out_buf = NULL;
size_t len = EC_KEY_priv2oct(key, NULL, 0);
if (len == 0) {
return 0;
}
uint8_t *buf = OPENSSL_malloc(len);
if (buf == NULL) {
return 0;
}
len = EC_KEY_priv2oct(key, buf, len);
if (len == 0) {
OPENSSL_free(buf);
return 0;
}
*out_buf = buf;
return len;
}
int EC_KEY_generate_key(EC_KEY *key) {
if (key == NULL || key->group == NULL) {
OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
// Check that the group order is FIPS compliant (FIPS 186-4 B.4.2).
if (EC_GROUP_order_bits(key->group) < 160) {
OPENSSL_PUT_ERROR(EC, EC_R_INVALID_GROUP_ORDER);
return 0;
}
static const uint8_t kDefaultAdditionalData[32] = {0};
EC_WRAPPED_SCALAR *priv_key = ec_wrapped_scalar_new(key->group);
EC_POINT *pub_key = EC_POINT_new(key->group);
if (priv_key == NULL || pub_key == NULL ||
// Generate the private key by testing candidates (FIPS 186-4 B.4.2).
!ec_random_nonzero_scalar(key->group, &priv_key->scalar,
kDefaultAdditionalData) ||
!ec_point_mul_scalar_base(key->group, &pub_key->raw, &priv_key->scalar)) {
EC_POINT_free(pub_key);
ec_wrapped_scalar_free(priv_key);
return 0;
}
// The public key is derived from the private key, but it is public.
//
// TODO(crbug.com/boringssl/677): This isn't quite right. While |pub_key|
// represents a public point, it is still in Jacobian form and the exact
// Jacobian representation is secret. We need to make it affine first. See
// discussion in the bug.
CONSTTIME_DECLASSIFY(&pub_key->raw, sizeof(pub_key->raw));
ec_wrapped_scalar_free(key->priv_key);
key->priv_key = priv_key;
EC_POINT_free(key->pub_key);
key->pub_key = pub_key;
return 1;
}
int EC_KEY_generate_key_fips(EC_KEY *eckey) {
if (eckey == NULL || eckey->group == NULL) {
OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
boringssl_ensure_ecc_self_test();
if (EC_KEY_generate_key(eckey) && EC_KEY_check_fips(eckey)) {
return 1;
}
EC_POINT_free(eckey->pub_key);
ec_wrapped_scalar_free(eckey->priv_key);
eckey->pub_key = NULL;
eckey->priv_key = NULL;
return 0;
}
int EC_KEY_get_ex_new_index(long argl, void *argp, CRYPTO_EX_unused *unused,
CRYPTO_EX_dup *dup_unused,
CRYPTO_EX_free *free_func) {
return CRYPTO_get_ex_new_index_ex(g_ec_ex_data_class_bss_get(), argl, argp,
free_func);
}
int EC_KEY_set_ex_data(EC_KEY *d, int idx, void *arg) {
return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
}
void *EC_KEY_get_ex_data(const EC_KEY *d, int idx) {
return CRYPTO_get_ex_data(&d->ex_data, idx);
}
void EC_KEY_set_asn1_flag(EC_KEY *key, int flag) {}