-/* crypto/ec/ec2_smpl.c */
-/* ====================================================================
- * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
- *
- * The Elliptic Curve Public-Key Crypto Library (ECC Code) included
- * herein is developed by SUN MICROSYSTEMS, INC., and is contributed
- * to the OpenSSL project.
- *
- * The ECC Code is licensed pursuant to the OpenSSL open source
- * license provided below.
- *
- * The software is originally written by Sheueling Chang Shantz and
- * Douglas Stebila of Sun Microsystems Laboratories.
- *
- */
-/* ====================================================================
- * Copyright (c) 1998-2002 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 2002-2018 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright (c) 2002, Oracle and/or its affiliates. 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 <openssl/err.h>
-#include "ec_lcl.h"
+#include "crypto/bn.h"
+#include "ec_local.h"
+#ifndef OPENSSL_NO_EC2M
-const EC_METHOD *EC_GF2m_simple_method(void)
- {
- static const EC_METHOD ret = {
- NID_X9_62_characteristic_two_field,
- ec_GF2m_simple_group_init,
- ec_GF2m_simple_group_finish,
- ec_GF2m_simple_group_clear_finish,
- ec_GF2m_simple_group_copy,
- ec_GF2m_simple_group_set_curve,
- ec_GF2m_simple_group_get_curve,
- ec_GF2m_simple_group_get_degree,
- ec_GF2m_simple_group_check_discriminant,
- ec_GF2m_simple_point_init,
- ec_GF2m_simple_point_finish,
- ec_GF2m_simple_point_clear_finish,
- ec_GF2m_simple_point_copy,
- ec_GF2m_simple_point_set_to_infinity,
- 0 /* set_Jprojective_coordinates_GFp */,
- 0 /* get_Jprojective_coordinates_GFp */,
- ec_GF2m_simple_point_set_affine_coordinates,
- ec_GF2m_simple_point_get_affine_coordinates,
- ec_GF2m_simple_set_compressed_coordinates,
- ec_GF2m_simple_point2oct,
- ec_GF2m_simple_oct2point,
- ec_GF2m_simple_add,
- ec_GF2m_simple_dbl,
- ec_GF2m_simple_invert,
- ec_GF2m_simple_mul,
- ec_GF2m_precompute_mult,
- ec_GF2m_simple_is_at_infinity,
- ec_GF2m_simple_is_on_curve,
- ec_GF2m_simple_cmp,
- ec_GF2m_simple_make_affine,
- ec_GF2m_simple_points_make_affine,
- ec_GF2m_simple_field_mul,
- ec_GF2m_simple_field_sqr,
- ec_GF2m_simple_field_div,
- 0 /* field_encode */,
- 0 /* field_decode */,
- 0 /* field_set_to_one */ };
-
- return &ret;
- }
-
-
-/* Initialize a GF(2^m)-based EC_GROUP structure.
- * Note that all other members are handled by EC_GROUP_new.
+/*
+ * Initialize a GF(2^m)-based EC_GROUP structure. Note that all other members
+ * are handled by EC_GROUP_new.
*/
int ec_GF2m_simple_group_init(EC_GROUP *group)
- {
- BN_init(&group->field);
- BN_init(&group->a);
- BN_init(&group->b);
- return 1;
- }
-
-
-/* Free a GF(2^m)-based EC_GROUP structure.
- * Note that all other members are handled by EC_GROUP_free.
+{
+ group->field = BN_new();
+ group->a = BN_new();
+ group->b = BN_new();
+
+ if (group->field == NULL || group->a == NULL || group->b == NULL) {
+ BN_free(group->field);
+ BN_free(group->a);
+ BN_free(group->b);
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * Free a GF(2^m)-based EC_GROUP structure. Note that all other members are
+ * handled by EC_GROUP_free.
*/
void ec_GF2m_simple_group_finish(EC_GROUP *group)
- {
- BN_free(&group->field);
- BN_free(&group->a);
- BN_free(&group->b);
- }
-
-
-/* Clear and free a GF(2^m)-based EC_GROUP structure.
- * Note that all other members are handled by EC_GROUP_clear_free.
+{
+ BN_free(group->field);
+ BN_free(group->a);
+ BN_free(group->b);
+}
+
+/*
+ * Clear and free a GF(2^m)-based EC_GROUP structure. Note that all other
+ * members are handled by EC_GROUP_clear_free.
*/
void ec_GF2m_simple_group_clear_finish(EC_GROUP *group)
- {
- BN_clear_free(&group->field);
- BN_clear_free(&group->a);
- BN_clear_free(&group->b);
- group->poly[0] = 0;
- group->poly[1] = 0;
- group->poly[2] = 0;
- group->poly[3] = 0;
- group->poly[4] = 0;
- }
-
-
-/* Copy a GF(2^m)-based EC_GROUP structure.
- * Note that all other members are handled by EC_GROUP_copy.
+{
+ BN_clear_free(group->field);
+ BN_clear_free(group->a);
+ BN_clear_free(group->b);
+ group->poly[0] = 0;
+ group->poly[1] = 0;
+ group->poly[2] = 0;
+ group->poly[3] = 0;
+ group->poly[4] = 0;
+ group->poly[5] = -1;
+}
+
+/*
+ * Copy a GF(2^m)-based EC_GROUP structure. Note that all other members are
+ * handled by EC_GROUP_copy.
*/
int ec_GF2m_simple_group_copy(EC_GROUP *dest, const EC_GROUP *src)
- {
- int i;
- if (!BN_copy(&dest->field, &src->field)) return 0;
- if (!BN_copy(&dest->a, &src->a)) return 0;
- if (!BN_copy(&dest->b, &src->b)) return 0;
- dest->poly[0] = src->poly[0];
- dest->poly[1] = src->poly[1];
- dest->poly[2] = src->poly[2];
- dest->poly[3] = src->poly[3];
- dest->poly[4] = src->poly[4];
- bn_wexpand(&dest->a, (dest->poly[0] + BN_BITS2 - 1) / BN_BITS2);
- bn_wexpand(&dest->b, (dest->poly[0] + BN_BITS2 - 1) / BN_BITS2);
- for (i = dest->a.top; i < dest->a.dmax; i++) dest->a.d[i] = 0;
- for (i = dest->b.top; i < dest->b.dmax; i++) dest->b.d[i] = 0;
- return 1;
- }
-
+{
+ if (!BN_copy(dest->field, src->field))
+ return 0;
+ if (!BN_copy(dest->a, src->a))
+ return 0;
+ if (!BN_copy(dest->b, src->b))
+ return 0;
+ dest->poly[0] = src->poly[0];
+ dest->poly[1] = src->poly[1];
+ dest->poly[2] = src->poly[2];
+ dest->poly[3] = src->poly[3];
+ dest->poly[4] = src->poly[4];
+ dest->poly[5] = src->poly[5];
+ if (bn_wexpand(dest->a, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2) ==
+ NULL)
+ return 0;
+ if (bn_wexpand(dest->b, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2) ==
+ NULL)
+ return 0;
+ bn_set_all_zero(dest->a);
+ bn_set_all_zero(dest->b);
+ return 1;
+}
/* Set the curve parameters of an EC_GROUP structure. */
int ec_GF2m_simple_group_set_curve(EC_GROUP *group,
- const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
- {
- int ret = 0, i;
-
- /* group->field */
- if (!BN_copy(&group->field, p)) goto err;
- i = BN_GF2m_poly2arr(&group->field, group->poly, 5);
- if ((i != 5) && (i != 3))
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_SET_CURVE, EC_R_UNSUPPORTED_FIELD);
- goto err;
- }
-
- /* group->a */
- if (!BN_GF2m_mod_arr(&group->a, a, group->poly)) goto err;
- bn_wexpand(&group->a, (group->poly[0] + BN_BITS2 - 1) / BN_BITS2);
- for (i = group->a.top; i < group->a.dmax; i++) group->a.d[i] = 0;
-
- /* group->b */
- if (!BN_GF2m_mod_arr(&group->b, b, group->poly)) goto err;
- bn_wexpand(&group->b, (group->poly[0] + BN_BITS2 - 1) / BN_BITS2);
- for (i = group->b.top; i < group->b.dmax; i++) group->b.d[i] = 0;
-
- ret = 1;
- err:
- return ret;
- }
-
-
-/* Get the curve parameters of an EC_GROUP structure.
- * If p, a, or b are NULL then there values will not be set but the method will return with success.
+ const BIGNUM *p, const BIGNUM *a,
+ const BIGNUM *b, BN_CTX *ctx)
+{
+ int ret = 0, i;
+
+ /* group->field */
+ if (!BN_copy(group->field, p))
+ goto err;
+ i = BN_GF2m_poly2arr(group->field, group->poly, 6) - 1;
+ if ((i != 5) && (i != 3)) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_SET_CURVE, EC_R_UNSUPPORTED_FIELD);
+ goto err;
+ }
+
+ /* group->a */
+ if (!BN_GF2m_mod_arr(group->a, a, group->poly))
+ goto err;
+ if (bn_wexpand(group->a, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2)
+ == NULL)
+ goto err;
+ bn_set_all_zero(group->a);
+
+ /* group->b */
+ if (!BN_GF2m_mod_arr(group->b, b, group->poly))
+ goto err;
+ if (bn_wexpand(group->b, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2)
+ == NULL)
+ goto err;
+ bn_set_all_zero(group->b);
+
+ ret = 1;
+ err:
+ return ret;
+}
+
+/*
+ * Get the curve parameters of an EC_GROUP structure. If p, a, or b are NULL
+ * then there values will not be set but the method will return with success.
*/
-int ec_GF2m_simple_group_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
- {
- int ret = 0;
-
- if (p != NULL)
- {
- if (!BN_copy(p, &group->field)) return 0;
- }
-
- if (a != NULL)
- {
- if (!BN_copy(a, &group->a)) goto err;
- }
-
- if (b != NULL)
- {
- if (!BN_copy(b, &group->b)) goto err;
- }
-
- ret = 1;
-
- err:
- return ret;
- }
-
-
-/* Gets the degree of the field. For a curve over GF(2^m) this is the value m. */
-int ec_GF2m_simple_group_get_degree(const EC_GROUP *group)
- {
- return BN_num_bits(&group->field)-1;
- }
+int ec_GF2m_simple_group_get_curve(const EC_GROUP *group, BIGNUM *p,
+ BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
+{
+ int ret = 0;
+
+ if (p != NULL) {
+ if (!BN_copy(p, group->field))
+ return 0;
+ }
+
+ if (a != NULL) {
+ if (!BN_copy(a, group->a))
+ goto err;
+ }
+ if (b != NULL) {
+ if (!BN_copy(b, group->b))
+ goto err;
+ }
+
+ ret = 1;
+
+ err:
+ return ret;
+}
-/* Checks the discriminant of the curve.
- * y^2 + x*y = x^3 + a*x^2 + b is an elliptic curve <=> b != 0 (mod p)
+/*
+ * Gets the degree of the field. For a curve over GF(2^m) this is the value
+ * m.
*/
-int ec_GF2m_simple_group_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
- {
- int ret = 0;
- BIGNUM *b;
- BN_CTX *new_ctx = NULL;
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_CHECK_DISCRIMINANT, ERR_R_MALLOC_FAILURE);
- goto err;
- }
- }
- BN_CTX_start(ctx);
- b = BN_CTX_get(ctx);
- if (b == NULL) goto err;
-
- if (!BN_GF2m_mod_arr(b, &group->b, group->poly)) goto err;
-
- /* check the discriminant:
- * y^2 + x*y = x^3 + a*x^2 + b is an elliptic curve <=> b != 0 (mod p)
- */
- if (BN_is_zero(b)) goto err;
-
- ret = 1;
-
-err:
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return ret;
- }
+int ec_GF2m_simple_group_get_degree(const EC_GROUP *group)
+{
+ return BN_num_bits(group->field) - 1;
+}
+
+/*
+ * Checks the discriminant of the curve. y^2 + x*y = x^3 + a*x^2 + b is an
+ * elliptic curve <=> b != 0 (mod p)
+ */
+int ec_GF2m_simple_group_check_discriminant(const EC_GROUP *group,
+ BN_CTX *ctx)
+{
+ int ret = 0;
+ BIGNUM *b;
+#ifndef FIPS_MODE
+ BN_CTX *new_ctx = NULL;
+
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_CHECK_DISCRIMINANT,
+ ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+ }
+#endif
+ BN_CTX_start(ctx);
+ b = BN_CTX_get(ctx);
+ if (b == NULL)
+ goto err;
+
+ if (!BN_GF2m_mod_arr(b, group->b, group->poly))
+ goto err;
+
+ /*
+ * check the discriminant: y^2 + x*y = x^3 + a*x^2 + b is an elliptic
+ * curve <=> b != 0 (mod p)
+ */
+ if (BN_is_zero(b))
+ goto err;
+
+ ret = 1;
+ err:
+ BN_CTX_end(ctx);
+#ifndef FIPS_MODE
+ BN_CTX_free(new_ctx);
+#endif
+ return ret;
+}
/* Initializes an EC_POINT. */
int ec_GF2m_simple_point_init(EC_POINT *point)
- {
- BN_init(&point->X);
- BN_init(&point->Y);
- BN_init(&point->Z);
- return 1;
- }
-
+{
+ point->X = BN_new();
+ point->Y = BN_new();
+ point->Z = BN_new();
+
+ if (point->X == NULL || point->Y == NULL || point->Z == NULL) {
+ BN_free(point->X);
+ BN_free(point->Y);
+ BN_free(point->Z);
+ return 0;
+ }
+ return 1;
+}
/* Frees an EC_POINT. */
void ec_GF2m_simple_point_finish(EC_POINT *point)
- {
- BN_free(&point->X);
- BN_free(&point->Y);
- BN_free(&point->Z);
- }
-
+{
+ BN_free(point->X);
+ BN_free(point->Y);
+ BN_free(point->Z);
+}
/* Clears and frees an EC_POINT. */
void ec_GF2m_simple_point_clear_finish(EC_POINT *point)
- {
- BN_clear_free(&point->X);
- BN_clear_free(&point->Y);
- BN_clear_free(&point->Z);
- point->Z_is_one = 0;
- }
-
-
-/* Copy the contents of one EC_POINT into another. Assumes dest is initialized. */
+{
+ BN_clear_free(point->X);
+ BN_clear_free(point->Y);
+ BN_clear_free(point->Z);
+ point->Z_is_one = 0;
+}
+
+/*
+ * Copy the contents of one EC_POINT into another. Assumes dest is
+ * initialized.
+ */
int ec_GF2m_simple_point_copy(EC_POINT *dest, const EC_POINT *src)
- {
- if (!BN_copy(&dest->X, &src->X)) return 0;
- if (!BN_copy(&dest->Y, &src->Y)) return 0;
- if (!BN_copy(&dest->Z, &src->Z)) return 0;
- dest->Z_is_one = src->Z_is_one;
-
- return 1;
- }
+{
+ if (!BN_copy(dest->X, src->X))
+ return 0;
+ if (!BN_copy(dest->Y, src->Y))
+ return 0;
+ if (!BN_copy(dest->Z, src->Z))
+ return 0;
+ dest->Z_is_one = src->Z_is_one;
+ dest->curve_name = src->curve_name;
+
+ return 1;
+}
+
+/*
+ * Set an EC_POINT to the point at infinity. A point at infinity is
+ * represented by having Z=0.
+ */
+int ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *group,
+ EC_POINT *point)
+{
+ point->Z_is_one = 0;
+ BN_zero(point->Z);
+ return 1;
+}
+
+/*
+ * Set the coordinates of an EC_POINT using affine coordinates. Note that
+ * the simple implementation only uses affine coordinates.
+ */
+int ec_GF2m_simple_point_set_affine_coordinates(const EC_GROUP *group,
+ EC_POINT *point,
+ const BIGNUM *x,
+ const BIGNUM *y, BN_CTX *ctx)
+{
+ int ret = 0;
+ if (x == NULL || y == NULL) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_POINT_SET_AFFINE_COORDINATES,
+ ERR_R_PASSED_NULL_PARAMETER);
+ return 0;
+ }
+
+ if (!BN_copy(point->X, x))
+ goto err;
+ BN_set_negative(point->X, 0);
+ if (!BN_copy(point->Y, y))
+ goto err;
+ BN_set_negative(point->Y, 0);
+ if (!BN_copy(point->Z, BN_value_one()))
+ goto err;
+ BN_set_negative(point->Z, 0);
+ point->Z_is_one = 1;
+ ret = 1;
+ err:
+ return ret;
+}
-/* Set an EC_POINT to the point at infinity.
- * A point at infinity is represented by having Z=0.
+/*
+ * Gets the affine coordinates of an EC_POINT. Note that the simple
+ * implementation only uses affine coordinates.
*/
-int ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
- {
- point->Z_is_one = 0;
- return (BN_zero(&point->Z));
- }
+int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *group,
+ const EC_POINT *point,
+ BIGNUM *x, BIGNUM *y,
+ BN_CTX *ctx)
+{
+ int ret = 0;
+
+ if (EC_POINT_is_at_infinity(group, point)) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_POINT_GET_AFFINE_COORDINATES,
+ EC_R_POINT_AT_INFINITY);
+ return 0;
+ }
+
+ if (BN_cmp(point->Z, BN_value_one())) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_POINT_GET_AFFINE_COORDINATES,
+ ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
+ return 0;
+ }
+ if (x != NULL) {
+ if (!BN_copy(x, point->X))
+ goto err;
+ BN_set_negative(x, 0);
+ }
+ if (y != NULL) {
+ if (!BN_copy(y, point->Y))
+ goto err;
+ BN_set_negative(y, 0);
+ }
+ ret = 1;
+ err:
+ return ret;
+}
-/* Set the coordinates of an EC_POINT using affine coordinates.
- * Note that the simple implementation only uses affine coordinates.
- */
-int ec_GF2m_simple_point_set_affine_coordinates(const EC_GROUP *group, EC_POINT *point,
- const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx)
- {
- int ret = 0;
- if (x == NULL || y == NULL)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT_SET_AFFINE_COORDINATES, ERR_R_PASSED_NULL_PARAMETER);
- return 0;
- }
-
- if (!BN_copy(&point->X, x)) goto err;
- BN_set_sign(&point->X, 0);
- if (!BN_copy(&point->Y, y)) goto err;
- BN_set_sign(&point->Y, 0);
- if (!BN_copy(&point->Z, BN_value_one())) goto err;
- BN_set_sign(&point->Z, 0);
- point->Z_is_one = 1;
- ret = 1;
-
- err:
- return ret;
- }
-
-
-/* Gets the affine coordinates of an EC_POINT.
- * Note that the simple implementation only uses affine coordinates.
+/*
+ * Computes a + b and stores the result in r. r could be a or b, a could be
+ * b. Uses algorithm A.10.2 of IEEE P1363.
*/
-int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *group, const EC_POINT *point,
- BIGNUM *x, BIGNUM *y, BN_CTX *ctx)
- {
- int ret = 0;
-
- if (EC_POINT_is_at_infinity(group, point))
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT_GET_AFFINE_COORDINATES, EC_R_POINT_AT_INFINITY);
- return 0;
- }
-
- if (BN_cmp(&point->Z, BN_value_one()))
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT_GET_AFFINE_COORDINATES, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
- return 0;
- }
- if (x != NULL)
- {
- if (!BN_copy(x, &point->X)) goto err;
- BN_set_sign(x, 0);
- }
- if (y != NULL)
- {
- if (!BN_copy(y, &point->Y)) goto err;
- BN_set_sign(y, 0);
- }
- ret = 1;
-
+int ec_GF2m_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
+ const EC_POINT *b, BN_CTX *ctx)
+{
+ BIGNUM *x0, *y0, *x1, *y1, *x2, *y2, *s, *t;
+ int ret = 0;
+#ifndef FIPS_MODE
+ BN_CTX *new_ctx = NULL;
+#endif
+
+ if (EC_POINT_is_at_infinity(group, a)) {
+ if (!EC_POINT_copy(r, b))
+ return 0;
+ return 1;
+ }
+
+ if (EC_POINT_is_at_infinity(group, b)) {
+ if (!EC_POINT_copy(r, a))
+ return 0;
+ return 1;
+ }
+
+#ifndef FIPS_MODE
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+#endif
+
+ BN_CTX_start(ctx);
+ x0 = BN_CTX_get(ctx);
+ y0 = BN_CTX_get(ctx);
+ x1 = BN_CTX_get(ctx);
+ y1 = BN_CTX_get(ctx);
+ x2 = BN_CTX_get(ctx);
+ y2 = BN_CTX_get(ctx);
+ s = BN_CTX_get(ctx);
+ t = BN_CTX_get(ctx);
+ if (t == NULL)
+ goto err;
+
+ if (a->Z_is_one) {
+ if (!BN_copy(x0, a->X))
+ goto err;
+ if (!BN_copy(y0, a->Y))
+ goto err;
+ } else {
+ if (!EC_POINT_get_affine_coordinates(group, a, x0, y0, ctx))
+ goto err;
+ }
+ if (b->Z_is_one) {
+ if (!BN_copy(x1, b->X))
+ goto err;
+ if (!BN_copy(y1, b->Y))
+ goto err;
+ } else {
+ if (!EC_POINT_get_affine_coordinates(group, b, x1, y1, ctx))
+ goto err;
+ }
+
+ if (BN_GF2m_cmp(x0, x1)) {
+ if (!BN_GF2m_add(t, x0, x1))
+ goto err;
+ if (!BN_GF2m_add(s, y0, y1))
+ goto err;
+ if (!group->meth->field_div(group, s, s, t, ctx))
+ goto err;
+ if (!group->meth->field_sqr(group, x2, s, ctx))
+ goto err;
+ if (!BN_GF2m_add(x2, x2, group->a))
+ goto err;
+ if (!BN_GF2m_add(x2, x2, s))
+ goto err;
+ if (!BN_GF2m_add(x2, x2, t))
+ goto err;
+ } else {
+ if (BN_GF2m_cmp(y0, y1) || BN_is_zero(x1)) {
+ if (!EC_POINT_set_to_infinity(group, r))
+ goto err;
+ ret = 1;
+ goto err;
+ }
+ if (!group->meth->field_div(group, s, y1, x1, ctx))
+ goto err;
+ if (!BN_GF2m_add(s, s, x1))
+ goto err;
+
+ if (!group->meth->field_sqr(group, x2, s, ctx))
+ goto err;
+ if (!BN_GF2m_add(x2, x2, s))
+ goto err;
+ if (!BN_GF2m_add(x2, x2, group->a))
+ goto err;
+ }
+
+ if (!BN_GF2m_add(y2, x1, x2))
+ goto err;
+ if (!group->meth->field_mul(group, y2, y2, s, ctx))
+ goto err;
+ if (!BN_GF2m_add(y2, y2, x2))
+ goto err;
+ if (!BN_GF2m_add(y2, y2, y1))
+ goto err;
+
+ if (!EC_POINT_set_affine_coordinates(group, r, x2, y2, ctx))
+ goto err;
+
+ ret = 1;
+
err:
- return ret;
- }
+ BN_CTX_end(ctx);
+#ifndef FIPS_MODE
+ BN_CTX_free(new_ctx);
+#endif
+ return ret;
+}
+/*
+ * Computes 2 * a and stores the result in r. r could be a. Uses algorithm
+ * A.10.2 of IEEE P1363.
+ */
+int ec_GF2m_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
+ BN_CTX *ctx)
+{
+ return ec_GF2m_simple_add(group, r, a, a, ctx);
+}
-/* Include patented algorithms. */
-#include "ec2_smpt.c"
+int ec_GF2m_simple_invert(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
+{
+ if (EC_POINT_is_at_infinity(group, point) || BN_is_zero(point->Y))
+ /* point is its own inverse */
+ return 1;
+ if (!EC_POINT_make_affine(group, point, ctx))
+ return 0;
+ return BN_GF2m_add(point->Y, point->X, point->Y);
+}
-/* Converts an EC_POINT to an octet string.
- * If buf is NULL, the encoded length will be returned.
- * If the length len of buf is smaller than required an error will be returned.
- *
- * The point compression section of this function is patented by Certicom Corp.
- * under US Patent 6,141,420. Point compression is disabled by default and can
- * be enabled by defining the preprocessor macro OPENSSL_EC_BIN_PT_COMP at
- * Configure-time.
+/* Indicates whether the given point is the point at infinity. */
+int ec_GF2m_simple_is_at_infinity(const EC_GROUP *group,
+ const EC_POINT *point)
+{
+ return BN_is_zero(point->Z);
+}
+
+/*-
+ * Determines whether the given EC_POINT is an actual point on the curve defined
+ * in the EC_GROUP. A point is valid if it satisfies the Weierstrass equation:
+ * y^2 + x*y = x^3 + a*x^2 + b.
*/
-size_t ec_GF2m_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, point_conversion_form_t form,
- unsigned char *buf, size_t len, BN_CTX *ctx)
- {
- size_t ret;
- BN_CTX *new_ctx = NULL;
- int used_ctx = 0;
- BIGNUM *x, *y, *yxi;
- size_t field_len, i, skip;
-
-#ifndef OPENSSL_EC_BIN_PT_COMP
- if ((form == POINT_CONVERSION_COMPRESSED) || (form == POINT_CONVERSION_HYBRID))
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_DISABLED);
- goto err;
- }
+int ec_GF2m_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
+ BN_CTX *ctx)
+{
+ int ret = -1;
+ BIGNUM *lh, *y2;
+ int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
+ const BIGNUM *, BN_CTX *);
+ int (*field_sqr) (const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
+#ifndef FIPS_MODE
+ BN_CTX *new_ctx = NULL;
#endif
- if ((form != POINT_CONVERSION_COMPRESSED)
- && (form != POINT_CONVERSION_UNCOMPRESSED)
- && (form != POINT_CONVERSION_HYBRID))
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);
- goto err;
- }
-
- if (EC_POINT_is_at_infinity(group, point))
- {
- /* encodes to a single 0 octet */
- if (buf != NULL)
- {
- if (len < 1)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
- return 0;
- }
- buf[0] = 0;
- }
- return 1;
- }
-
-
- /* ret := required output buffer length */
- field_len = (EC_GROUP_get_degree(group) + 7) / 8;
- ret = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
-
- /* if 'buf' is NULL, just return required length */
- if (buf != NULL)
- {
- if (len < ret)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
- goto err;
- }
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return 0;
- }
-
- BN_CTX_start(ctx);
- used_ctx = 1;
- x = BN_CTX_get(ctx);
- y = BN_CTX_get(ctx);
- yxi = BN_CTX_get(ctx);
- if (yxi == NULL) goto err;
-
- if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
-
- buf[0] = form;
-#ifdef OPENSSL_EC_BIN_PT_COMP
- if ((form != POINT_CONVERSION_UNCOMPRESSED) && !BN_is_zero(x))
- {
- if (!group->meth->field_div(group, yxi, y, x, ctx)) goto err;
- if (BN_is_odd(yxi)) buf[0]++;
- }
+ if (EC_POINT_is_at_infinity(group, point))
+ return 1;
+
+ field_mul = group->meth->field_mul;
+ field_sqr = group->meth->field_sqr;
+
+ /* only support affine coordinates */
+ if (!point->Z_is_one)
+ return -1;
+
+#ifndef FIPS_MODE
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return -1;
+ }
#endif
- i = 1;
-
- skip = field_len - BN_num_bytes(x);
- if (skip > field_len)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
- }
- while (skip > 0)
- {
- buf[i++] = 0;
- skip--;
- }
- skip = BN_bn2bin(x, buf + i);
- i += skip;
- if (i != 1 + field_len)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
- }
-
- if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_HYBRID)
- {
- skip = field_len - BN_num_bytes(y);
- if (skip > field_len)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
- }
- while (skip > 0)
- {
- buf[i++] = 0;
- skip--;
- }
- skip = BN_bn2bin(y, buf + i);
- i += skip;
- }
-
- if (i != ret)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
- }
- }
-
- if (used_ctx)
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return ret;
+ BN_CTX_start(ctx);
+ y2 = BN_CTX_get(ctx);
+ lh = BN_CTX_get(ctx);
+ if (lh == NULL)
+ goto err;
+
+ /*-
+ * We have a curve defined by a Weierstrass equation
+ * y^2 + x*y = x^3 + a*x^2 + b.
+ * <=> x^3 + a*x^2 + x*y + b + y^2 = 0
+ * <=> ((x + a) * x + y ) * x + b + y^2 = 0
+ */
+ if (!BN_GF2m_add(lh, point->X, group->a))
+ goto err;
+ if (!field_mul(group, lh, lh, point->X, ctx))
+ goto err;
+ if (!BN_GF2m_add(lh, lh, point->Y))
+ goto err;
+ if (!field_mul(group, lh, lh, point->X, ctx))
+ goto err;
+ if (!BN_GF2m_add(lh, lh, group->b))
+ goto err;
+ if (!field_sqr(group, y2, point->Y, ctx))
+ goto err;
+ if (!BN_GF2m_add(lh, lh, y2))
+ goto err;
+ ret = BN_is_zero(lh);
err:
- if (used_ctx)
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return 0;
- }
-
+ BN_CTX_end(ctx);
+#ifndef FIPS_MODE
+ BN_CTX_free(new_ctx);
+#endif
+ return ret;
+}
-/* Converts an octet string representation to an EC_POINT.
- * Note that the simple implementation only uses affine coordinates.
+/*-
+ * Indicates whether two points are equal.
+ * Return values:
+ * -1 error
+ * 0 equal (in affine coordinates)
+ * 1 not equal
*/
-int ec_GF2m_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
- const unsigned char *buf, size_t len, BN_CTX *ctx)
- {
- point_conversion_form_t form;
- int y_bit;
- BN_CTX *new_ctx = NULL;
- BIGNUM *x, *y, *yxi;
- size_t field_len, enc_len;
- int ret = 0;
-
- if (len == 0)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);
- return 0;
- }
- form = buf[0];
- y_bit = form & 1;
- form = form & ~1;
- if ((form != 0) && (form != POINT_CONVERSION_COMPRESSED)
- && (form != POINT_CONVERSION_UNCOMPRESSED)
- && (form != POINT_CONVERSION_HYBRID))
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- return 0;
- }
- if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- return 0;
- }
-
- if (form == 0)
- {
- if (len != 1)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- return 0;
- }
-
- return EC_POINT_set_to_infinity(group, point);
- }
-
- field_len = (EC_GROUP_get_degree(group) + 7) / 8;
- enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
-
- if (len != enc_len)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- return 0;
- }
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return 0;
- }
-
- BN_CTX_start(ctx);
- x = BN_CTX_get(ctx);
- y = BN_CTX_get(ctx);
- yxi = BN_CTX_get(ctx);
- if (yxi == NULL) goto err;
-
- if (!BN_bin2bn(buf + 1, field_len, x)) goto err;
- if (BN_ucmp(x, &group->field) >= 0)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- goto err;
- }
-
- if (form == POINT_CONVERSION_COMPRESSED)
- {
- if (!EC_POINT_set_compressed_coordinates_GF2m(group, point, x, y_bit, ctx)) goto err;
- }
- else
- {
- if (!BN_bin2bn(buf + 1 + field_len, field_len, y)) goto err;
- if (BN_ucmp(y, &group->field) >= 0)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- goto err;
- }
- if (form == POINT_CONVERSION_HYBRID)
- {
- if (!group->meth->field_div(group, yxi, y, x, ctx)) goto err;
- if (y_bit != BN_is_odd(yxi))
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- goto err;
- }
- }
-
- if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
- }
-
- if (!EC_POINT_is_on_curve(group, point, ctx)) /* test required by X9.62 */
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
- goto err;
- }
-
- ret = 1;
-
- err:
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return ret;
- }
+int ec_GF2m_simple_cmp(const EC_GROUP *group, const EC_POINT *a,
+ const EC_POINT *b, BN_CTX *ctx)
+{
+ BIGNUM *aX, *aY, *bX, *bY;
+ int ret = -1;
+#ifndef FIPS_MODE
+ BN_CTX *new_ctx = NULL;
+#endif
+ if (EC_POINT_is_at_infinity(group, a)) {
+ return EC_POINT_is_at_infinity(group, b) ? 0 : 1;
+ }
-/* Computes a + b and stores the result in r. r could be a or b, a could be b.
- * Uses algorithm A.10.2 of IEEE P1363.
- */
-int ec_GF2m_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx)
- {
- BN_CTX *new_ctx = NULL;
- BIGNUM *x0, *y0, *x1, *y1, *x2, *y2, *s, *t;
- int ret = 0;
-
- if (EC_POINT_is_at_infinity(group, a))
- {
- if (!EC_POINT_copy(r, b)) return 0;
- return 1;
- }
-
- if (EC_POINT_is_at_infinity(group, b))
- {
- if (!EC_POINT_copy(r, a)) return 0;
- return 1;
- }
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return 0;
- }
-
- BN_CTX_start(ctx);
- x0 = BN_CTX_get(ctx);
- y0 = BN_CTX_get(ctx);
- x1 = BN_CTX_get(ctx);
- y1 = BN_CTX_get(ctx);
- x2 = BN_CTX_get(ctx);
- y2 = BN_CTX_get(ctx);
- s = BN_CTX_get(ctx);
- t = BN_CTX_get(ctx);
- if (t == NULL) goto err;
-
- if (a->Z_is_one)
- {
- if (!BN_copy(x0, &a->X)) goto err;
- if (!BN_copy(y0, &a->Y)) goto err;
- }
- else
- {
- if (!EC_POINT_get_affine_coordinates_GF2m(group, a, x0, y0, ctx)) goto err;
- }
- if (b->Z_is_one)
- {
- if (!BN_copy(x1, &b->X)) goto err;
- if (!BN_copy(y1, &b->Y)) goto err;
- }
- else
- {
- if (!EC_POINT_get_affine_coordinates_GF2m(group, b, x1, y1, ctx)) goto err;
- }
-
-
- if (BN_GF2m_cmp(x0, x1))
- {
- if (!BN_GF2m_add(t, x0, x1)) goto err;
- if (!BN_GF2m_add(s, y0, y1)) goto err;
- if (!group->meth->field_div(group, s, s, t, ctx)) goto err;
- if (!group->meth->field_sqr(group, x2, s, ctx)) goto err;
- if (!BN_GF2m_add(x2, x2, &group->a)) goto err;
- if (!BN_GF2m_add(x2, x2, s)) goto err;
- if (!BN_GF2m_add(x2, x2, t)) goto err;
- }
- else
- {
- if (BN_GF2m_cmp(y0, y1) || BN_is_zero(x1))
- {
- if (!EC_POINT_set_to_infinity(group, r)) goto err;
- ret = 1;
- goto err;
- }
- if (!group->meth->field_div(group, s, y1, x1, ctx)) goto err;
- if (!BN_GF2m_add(s, s, x1)) goto err;
-
- if (!group->meth->field_sqr(group, x2, s, ctx)) goto err;
- if (!BN_GF2m_add(x2, x2, s)) goto err;
- if (!BN_GF2m_add(x2, x2, &group->a)) goto err;
- }
-
- if (!BN_GF2m_add(y2, x1, x2)) goto err;
- if (!group->meth->field_mul(group, y2, y2, s, ctx)) goto err;
- if (!BN_GF2m_add(y2, y2, x2)) goto err;
- if (!BN_GF2m_add(y2, y2, y1)) goto err;
-
- if (!EC_POINT_set_affine_coordinates_GF2m(group, r, x2, y2, ctx)) goto err;
-
- ret = 1;
+ if (EC_POINT_is_at_infinity(group, b))
+ return 1;
- err:
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return ret;
- }
+ if (a->Z_is_one && b->Z_is_one) {
+ return ((BN_cmp(a->X, b->X) == 0) && BN_cmp(a->Y, b->Y) == 0) ? 0 : 1;
+ }
+#ifndef FIPS_MODE
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return -1;
+ }
+#endif
-/* Computes 2 * a and stores the result in r. r could be a.
- * Uses algorithm A.10.2 of IEEE P1363.
- */
-int ec_GF2m_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, BN_CTX *ctx)
- {
- return ec_GF2m_simple_add(group, r, a, a, ctx);
- }
+ BN_CTX_start(ctx);
+ aX = BN_CTX_get(ctx);
+ aY = BN_CTX_get(ctx);
+ bX = BN_CTX_get(ctx);
+ bY = BN_CTX_get(ctx);
+ if (bY == NULL)
+ goto err;
+ if (!EC_POINT_get_affine_coordinates(group, a, aX, aY, ctx))
+ goto err;
+ if (!EC_POINT_get_affine_coordinates(group, b, bX, bY, ctx))
+ goto err;
+ ret = ((BN_cmp(aX, bX) == 0) && BN_cmp(aY, bY) == 0) ? 0 : 1;
-int ec_GF2m_simple_invert(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
- {
- if (EC_POINT_is_at_infinity(group, point) || BN_is_zero(&point->Y))
- /* point is its own inverse */
- return 1;
-
- if (!EC_POINT_make_affine(group, point, ctx)) return 0;
- return BN_GF2m_add(&point->Y, &point->X, &point->Y);
- }
+ err:
+ BN_CTX_end(ctx);
+#ifndef FIPS_MODE
+ BN_CTX_free(new_ctx);
+#endif
+ return ret;
+}
+/* Forces the given EC_POINT to internally use affine coordinates. */
+int ec_GF2m_simple_make_affine(const EC_GROUP *group, EC_POINT *point,
+ BN_CTX *ctx)
+{
+ BIGNUM *x, *y;
+ int ret = 0;
+#ifndef FIPS_MODE
+ BN_CTX *new_ctx = NULL;
+#endif
-/* Indicates whether the given point is the point at infinity. */
-int ec_GF2m_simple_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
- {
- return BN_is_zero(&point->Z);
- }
+ if (point->Z_is_one || EC_POINT_is_at_infinity(group, point))
+ return 1;
+#ifndef FIPS_MODE
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+#endif
-/* Determines whether the given EC_POINT is an actual point on the curve defined
- * in the EC_GROUP. A point is valid if it satisfies the Weierstrass equation:
- * y^2 + x*y = x^3 + a*x^2 + b.
- */
-int ec_GF2m_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx)
- {
- BN_CTX *new_ctx = NULL;
- BIGNUM *rh, *lh, *tmp1;
- int ret = -1;
-
- if (EC_POINT_is_at_infinity(group, point))
- return 1;
-
- /* only support affine coordinates */
- if (!point->Z_is_one) goto err;
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return -1;
- }
-
- BN_CTX_start(ctx);
- rh = BN_CTX_get(ctx);
- lh = BN_CTX_get(ctx);
- tmp1 = BN_CTX_get(ctx);
- if (tmp1 == NULL) goto err;
-
- /* We have a curve defined by a Weierstrass equation
- * y^2 + x*y = x^3 + a*x^2 + b.
- * To test this, we add up the right-hand side in 'rh'
- * and the left-hand side in 'lh'.
- */
-
- /* rh := X^3 */
- if (!group->meth->field_sqr(group, tmp1, &point->X, ctx)) goto err;
- if (!group->meth->field_mul(group, rh, tmp1, &point->X, ctx)) goto err;
-
- /* rh := rh + a*X^2 */
- if (!group->meth->field_mul(group, tmp1, tmp1, &group->a, ctx)) goto err;
- if (!BN_GF2m_add(rh, rh, tmp1)) goto err;
-
- /* rh := rh + b */
- if (!BN_GF2m_add(rh, rh, &group->b)) goto err;
-
- /* lh := Y^2 */
- if (!group->meth->field_sqr(group, lh, &point->Y, ctx)) goto err;
-
- /* lh := lh + x*y */
- if (!group->meth->field_mul(group, tmp1, &point->X, &point->Y, ctx)) goto err;
- if (!BN_GF2m_add(lh, lh, tmp1)) goto err;
-
- ret = (0 == BN_GF2m_cmp(lh, rh));
+ BN_CTX_start(ctx);
+ x = BN_CTX_get(ctx);
+ y = BN_CTX_get(ctx);
+ if (y == NULL)
+ goto err;
- err:
- if (ctx) BN_CTX_end(ctx);
- if (new_ctx) BN_CTX_free(new_ctx);
- return ret;
- }
+ if (!EC_POINT_get_affine_coordinates(group, point, x, y, ctx))
+ goto err;
+ if (!BN_copy(point->X, x))
+ goto err;
+ if (!BN_copy(point->Y, y))
+ goto err;
+ if (!BN_one(point->Z))
+ goto err;
+ point->Z_is_one = 1;
+ ret = 1;
-/* Indicates whether two points are equal.
- * Return values:
- * -1 error
- * 0 equal (in affine coordinates)
- * 1 not equal
+ err:
+ BN_CTX_end(ctx);
+#ifndef FIPS_MODE
+ BN_CTX_free(new_ctx);
+#endif
+ return ret;
+}
+
+/*
+ * Forces each of the EC_POINTs in the given array to use affine coordinates.
*/
-int ec_GF2m_simple_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx)
- {
- BIGNUM *aX, *aY, *bX, *bY;
- BN_CTX *new_ctx = NULL;
- int ret = -1;
-
- if (EC_POINT_is_at_infinity(group, a))
- {
- return EC_POINT_is_at_infinity(group, b) ? 0 : 1;
- }
-
- if (a->Z_is_one && b->Z_is_one)
- {
- return ((BN_cmp(&a->X, &b->X) == 0) && BN_cmp(&a->Y, &b->Y) == 0) ? 0 : 1;
- }
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return -1;
- }
-
- BN_CTX_start(ctx);
- aX = BN_CTX_get(ctx);
- aY = BN_CTX_get(ctx);
- bX = BN_CTX_get(ctx);
- bY = BN_CTX_get(ctx);
- if (bY == NULL) goto err;
-
- if (!EC_POINT_get_affine_coordinates_GF2m(group, a, aX, aY, ctx)) goto err;
- if (!EC_POINT_get_affine_coordinates_GF2m(group, b, bX, bY, ctx)) goto err;
- ret = ((BN_cmp(aX, bX) == 0) && BN_cmp(aY, bY) == 0) ? 0 : 1;
-
- err:
- if (ctx) BN_CTX_end(ctx);
- if (new_ctx) BN_CTX_free(new_ctx);
- return ret;
- }
+int ec_GF2m_simple_points_make_affine(const EC_GROUP *group, size_t num,
+ EC_POINT *points[], BN_CTX *ctx)
+{
+ size_t i;
+ for (i = 0; i < num; i++) {
+ if (!group->meth->make_affine(group, points[i], ctx))
+ return 0;
+ }
-/* Forces the given EC_POINT to internally use affine coordinates. */
-int ec_GF2m_simple_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
- {
- BN_CTX *new_ctx = NULL;
- BIGNUM *x, *y;
- int ret = 0;
-
- if (point->Z_is_one || EC_POINT_is_at_infinity(group, point))
- return 1;
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return 0;
- }
-
- BN_CTX_start(ctx);
- x = BN_CTX_get(ctx);
- y = BN_CTX_get(ctx);
- if (y == NULL) goto err;
-
- if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
- if (!BN_copy(&point->X, x)) goto err;
- if (!BN_copy(&point->Y, y)) goto err;
- if (!BN_one(&point->Z)) goto err;
-
- ret = 1;
-
- err:
- if (ctx) BN_CTX_end(ctx);
- if (new_ctx) BN_CTX_free(new_ctx);
- return ret;
- }
-
-
-/* Forces each of the EC_POINTs in the given array to use affine coordinates. */
-int ec_GF2m_simple_points_make_affine(const EC_GROUP *group, size_t num, EC_POINT *points[], BN_CTX *ctx)
- {
- size_t i;
-
- for (i = 0; i < num; i++)
- {
- if (!group->meth->make_affine(group, points[i], ctx)) return 0;
- }
-
- return 1;
- }
-
+ return 1;
+}
/* Wrapper to simple binary polynomial field multiplication implementation. */
-int ec_GF2m_simple_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
- {
- return BN_GF2m_mod_mul_arr(r, a, b, group->poly, ctx);
- }
-
+int ec_GF2m_simple_field_mul(const EC_GROUP *group, BIGNUM *r,
+ const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
+{
+ return BN_GF2m_mod_mul_arr(r, a, b, group->poly, ctx);
+}
/* Wrapper to simple binary polynomial field squaring implementation. */
-int ec_GF2m_simple_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
- {
- return BN_GF2m_mod_sqr_arr(r, a, group->poly, ctx);
- }
-
+int ec_GF2m_simple_field_sqr(const EC_GROUP *group, BIGNUM *r,
+ const BIGNUM *a, BN_CTX *ctx)
+{
+ return BN_GF2m_mod_sqr_arr(r, a, group->poly, ctx);
+}
/* Wrapper to simple binary polynomial field division implementation. */
-int ec_GF2m_simple_field_div(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
- {
- return BN_GF2m_mod_div(r, a, b, &group->field, ctx);
- }
+int ec_GF2m_simple_field_div(const EC_GROUP *group, BIGNUM *r,
+ const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
+{
+ return BN_GF2m_mod_div(r, a, b, group->field, ctx);
+}
+
+/*-
+ * Lopez-Dahab ladder, pre step.
+ * See e.g. "Guide to ECC" Alg 3.40.
+ * Modified to blind s and r independently.
+ * s:= p, r := 2p
+ */
+static
+int ec_GF2m_simple_ladder_pre(const EC_GROUP *group,
+ EC_POINT *r, EC_POINT *s,
+ EC_POINT *p, BN_CTX *ctx)
+{
+ /* if p is not affine, something is wrong */
+ if (p->Z_is_one == 0)
+ return 0;
+
+ /* s blinding: make sure lambda (s->Z here) is not zero */
+ do {
+ if (!BN_priv_rand_ex(s->Z, BN_num_bits(group->field) - 1,
+ BN_RAND_TOP_ANY, BN_RAND_BOTTOM_ANY, ctx)) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_LADDER_PRE, ERR_R_BN_LIB);
+ return 0;
+ }
+ } while (BN_is_zero(s->Z));
+
+ /* if field_encode defined convert between representations */
+ if ((group->meth->field_encode != NULL
+ && !group->meth->field_encode(group, s->Z, s->Z, ctx))
+ || !group->meth->field_mul(group, s->X, p->X, s->Z, ctx))
+ return 0;
+
+ /* r blinding: make sure lambda (r->Y here for storage) is not zero */
+ do {
+ if (!BN_priv_rand_ex(r->Y, BN_num_bits(group->field) - 1,
+ BN_RAND_TOP_ANY, BN_RAND_BOTTOM_ANY, ctx)) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_LADDER_PRE, ERR_R_BN_LIB);
+ return 0;
+ }
+ } while (BN_is_zero(r->Y));
+
+ if ((group->meth->field_encode != NULL
+ && !group->meth->field_encode(group, r->Y, r->Y, ctx))
+ || !group->meth->field_sqr(group, r->Z, p->X, ctx)
+ || !group->meth->field_sqr(group, r->X, r->Z, ctx)
+ || !BN_GF2m_add(r->X, r->X, group->b)
+ || !group->meth->field_mul(group, r->Z, r->Z, r->Y, ctx)
+ || !group->meth->field_mul(group, r->X, r->X, r->Y, ctx))
+ return 0;
+
+ s->Z_is_one = 0;
+ r->Z_is_one = 0;
+
+ return 1;
+}
+
+/*-
+ * Ladder step: differential addition-and-doubling, mixed Lopez-Dahab coords.
+ * http://www.hyperelliptic.org/EFD/g12o/auto-code/shortw/xz/ladder/mladd-2003-s.op3
+ * s := r + s, r := 2r
+ */
+static
+int ec_GF2m_simple_ladder_step(const EC_GROUP *group,
+ EC_POINT *r, EC_POINT *s,
+ EC_POINT *p, BN_CTX *ctx)
+{
+ if (!group->meth->field_mul(group, r->Y, r->Z, s->X, ctx)
+ || !group->meth->field_mul(group, s->X, r->X, s->Z, ctx)
+ || !group->meth->field_sqr(group, s->Y, r->Z, ctx)
+ || !group->meth->field_sqr(group, r->Z, r->X, ctx)
+ || !BN_GF2m_add(s->Z, r->Y, s->X)
+ || !group->meth->field_sqr(group, s->Z, s->Z, ctx)
+ || !group->meth->field_mul(group, s->X, r->Y, s->X, ctx)
+ || !group->meth->field_mul(group, r->Y, s->Z, p->X, ctx)
+ || !BN_GF2m_add(s->X, s->X, r->Y)
+ || !group->meth->field_sqr(group, r->Y, r->Z, ctx)
+ || !group->meth->field_mul(group, r->Z, r->Z, s->Y, ctx)
+ || !group->meth->field_sqr(group, s->Y, s->Y, ctx)
+ || !group->meth->field_mul(group, s->Y, s->Y, group->b, ctx)
+ || !BN_GF2m_add(r->X, r->Y, s->Y))
+ return 0;
+
+ return 1;
+}
+
+/*-
+ * Recover affine (x,y) result from Lopez-Dahab r and s, affine p.
+ * See e.g. "Fast Multiplication on Elliptic Curves over GF(2**m)
+ * without Precomputation" (Lopez and Dahab, CHES 1999),
+ * Appendix Alg Mxy.
+ */
+static
+int ec_GF2m_simple_ladder_post(const EC_GROUP *group,
+ EC_POINT *r, EC_POINT *s,
+ EC_POINT *p, BN_CTX *ctx)
+{
+ int ret = 0;
+ BIGNUM *t0, *t1, *t2 = NULL;
+
+ if (BN_is_zero(r->Z))
+ return EC_POINT_set_to_infinity(group, r);
+
+ if (BN_is_zero(s->Z)) {
+ if (!EC_POINT_copy(r, p)
+ || !EC_POINT_invert(group, r, ctx)) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_LADDER_POST, ERR_R_EC_LIB);
+ return 0;
+ }
+ return 1;
+ }
+
+ BN_CTX_start(ctx);
+ t0 = BN_CTX_get(ctx);
+ t1 = BN_CTX_get(ctx);
+ t2 = BN_CTX_get(ctx);
+ if (t2 == NULL) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_LADDER_POST, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+
+ if (!group->meth->field_mul(group, t0, r->Z, s->Z, ctx)
+ || !group->meth->field_mul(group, t1, p->X, r->Z, ctx)
+ || !BN_GF2m_add(t1, r->X, t1)
+ || !group->meth->field_mul(group, t2, p->X, s->Z, ctx)
+ || !group->meth->field_mul(group, r->Z, r->X, t2, ctx)
+ || !BN_GF2m_add(t2, t2, s->X)
+ || !group->meth->field_mul(group, t1, t1, t2, ctx)
+ || !group->meth->field_sqr(group, t2, p->X, ctx)
+ || !BN_GF2m_add(t2, p->Y, t2)
+ || !group->meth->field_mul(group, t2, t2, t0, ctx)
+ || !BN_GF2m_add(t1, t2, t1)
+ || !group->meth->field_mul(group, t2, p->X, t0, ctx)
+ || !group->meth->field_inv(group, t2, t2, ctx)
+ || !group->meth->field_mul(group, t1, t1, t2, ctx)
+ || !group->meth->field_mul(group, r->X, r->Z, t2, ctx)
+ || !BN_GF2m_add(t2, p->X, r->X)
+ || !group->meth->field_mul(group, t2, t2, t1, ctx)
+ || !BN_GF2m_add(r->Y, p->Y, t2)
+ || !BN_one(r->Z))
+ goto err;
+
+ r->Z_is_one = 1;
+
+ /* GF(2^m) field elements should always have BIGNUM::neg = 0 */
+ BN_set_negative(r->X, 0);
+ BN_set_negative(r->Y, 0);
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ return ret;
+}
+
+static
+int ec_GF2m_simple_points_mul(const EC_GROUP *group, EC_POINT *r,
+ const BIGNUM *scalar, size_t num,
+ const EC_POINT *points[],
+ const BIGNUM *scalars[],
+ BN_CTX *ctx)
+{
+ int ret = 0;
+ EC_POINT *t = NULL;
+
+ /*-
+ * We limit use of the ladder only to the following cases:
+ * - r := scalar * G
+ * Fixed point mul: scalar != NULL && num == 0;
+ * - r := scalars[0] * points[0]
+ * Variable point mul: scalar == NULL && num == 1;
+ * - r := scalar * G + scalars[0] * points[0]
+ * used, e.g., in ECDSA verification: scalar != NULL && num == 1
+ *
+ * In any other case (num > 1) we use the default wNAF implementation.
+ *
+ * We also let the default implementation handle degenerate cases like group
+ * order or cofactor set to 0.
+ */
+ if (num > 1 || BN_is_zero(group->order) || BN_is_zero(group->cofactor))
+ return ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
+
+ if (scalar != NULL && num == 0)
+ /* Fixed point multiplication */
+ return ec_scalar_mul_ladder(group, r, scalar, NULL, ctx);
+
+ if (scalar == NULL && num == 1)
+ /* Variable point multiplication */
+ return ec_scalar_mul_ladder(group, r, scalars[0], points[0], ctx);
+
+ /*-
+ * Double point multiplication:
+ * r := scalar * G + scalars[0] * points[0]
+ */
+
+ if ((t = EC_POINT_new(group)) == NULL) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_POINTS_MUL, ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+
+ if (!ec_scalar_mul_ladder(group, t, scalar, NULL, ctx)
+ || !ec_scalar_mul_ladder(group, r, scalars[0], points[0], ctx)
+ || !EC_POINT_add(group, r, t, r, ctx))
+ goto err;
+
+ ret = 1;
+
+ err:
+ EC_POINT_free(t);
+ return ret;
+}
+
+/*-
+ * Computes the multiplicative inverse of a in GF(2^m), storing the result in r.
+ * If a is zero (or equivalent), you'll get a EC_R_CANNOT_INVERT error.
+ * SCA hardening is with blinding: BN_GF2m_mod_inv does that.
+ */
+static int ec_GF2m_simple_field_inv(const EC_GROUP *group, BIGNUM *r,
+ const BIGNUM *a, BN_CTX *ctx)
+{
+ int ret;
+
+ if (!(ret = BN_GF2m_mod_inv(r, a, group->field, ctx)))
+ ECerr(EC_F_EC_GF2M_SIMPLE_FIELD_INV, EC_R_CANNOT_INVERT);
+ return ret;
+}
+
+const EC_METHOD *EC_GF2m_simple_method(void)
+{
+ static const EC_METHOD ret = {
+ EC_FLAGS_DEFAULT_OCT,
+ NID_X9_62_characteristic_two_field,
+ ec_GF2m_simple_group_init,
+ ec_GF2m_simple_group_finish,
+ ec_GF2m_simple_group_clear_finish,
+ ec_GF2m_simple_group_copy,
+ ec_GF2m_simple_group_set_curve,
+ ec_GF2m_simple_group_get_curve,
+ ec_GF2m_simple_group_get_degree,
+ ec_group_simple_order_bits,
+ ec_GF2m_simple_group_check_discriminant,
+ ec_GF2m_simple_point_init,
+ ec_GF2m_simple_point_finish,
+ ec_GF2m_simple_point_clear_finish,
+ ec_GF2m_simple_point_copy,
+ ec_GF2m_simple_point_set_to_infinity,
+ 0, /* set_Jprojective_coordinates_GFp */
+ 0, /* get_Jprojective_coordinates_GFp */
+ ec_GF2m_simple_point_set_affine_coordinates,
+ ec_GF2m_simple_point_get_affine_coordinates,
+ 0, /* point_set_compressed_coordinates */
+ 0, /* point2oct */
+ 0, /* oct2point */
+ ec_GF2m_simple_add,
+ ec_GF2m_simple_dbl,
+ ec_GF2m_simple_invert,
+ ec_GF2m_simple_is_at_infinity,
+ ec_GF2m_simple_is_on_curve,
+ ec_GF2m_simple_cmp,
+ ec_GF2m_simple_make_affine,
+ ec_GF2m_simple_points_make_affine,
+ ec_GF2m_simple_points_mul,
+ 0, /* precompute_mult */
+ 0, /* have_precompute_mult */
+ ec_GF2m_simple_field_mul,
+ ec_GF2m_simple_field_sqr,
+ ec_GF2m_simple_field_div,
+ ec_GF2m_simple_field_inv,
+ 0, /* field_encode */
+ 0, /* field_decode */
+ 0, /* field_set_to_one */
+ ec_key_simple_priv2oct,
+ ec_key_simple_oct2priv,
+ 0, /* set private */
+ ec_key_simple_generate_key,
+ ec_key_simple_check_key,
+ ec_key_simple_generate_public_key,
+ 0, /* keycopy */
+ 0, /* keyfinish */
+ ecdh_simple_compute_key,
+ ecdsa_simple_sign_setup,
+ ecdsa_simple_sign_sig,
+ ecdsa_simple_verify_sig,
+ 0, /* field_inverse_mod_ord */
+ 0, /* blind_coordinates */
+ ec_GF2m_simple_ladder_pre,
+ ec_GF2m_simple_ladder_step,
+ ec_GF2m_simple_ladder_post
+ };
+
+ return &ret;
+}
+
+#endif