X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fec%2Fec2_smpl.c;h=f377b1f11e24da1f1d51b4f545cbab82a9c62e0a;hp=2fcfb4f052f0d54166c56fd84bc264386bcd1f82;hb=9bf682f62bd819d2fbceb95eeabd61dd4532240f;hpb=23a22b4cf72b0c2aadcd65001d4a28941d570547 diff --git a/crypto/ec/ec2_smpl.c b/crypto/ec/ec2_smpl.c index 2fcfb4f052..f377b1f11e 100644 --- a/crypto/ec/ec2_smpl.c +++ b/crypto/ec/ec2_smpl.c @@ -1,74 +1,13 @@ -/* 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) 1998-2005 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 2002-2018 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 #include "internal/bn_int.h" @@ -76,537 +15,556 @@ #ifndef OPENSSL_NO_EC2M - -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_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, - 0,0,0, - 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, - - /* the following three method functions are defined in ec2_mult.c */ - ec_GF2m_simple_mul, - ec_GF2m_precompute_mult, - ec_GF2m_have_precompute_mult, - - 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) - { - group->field = BN_new(); - group->a = BN_new(); - group->b = BN_new(); - - if(!group->field || !group->a || !group->b) - { - if(group->field) BN_free(group->field); - if(group->a) BN_free(group->a); - if(group->b) 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. +{ + 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; - group->poly[5] = -1; - } - - -/* 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) - { - 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; - } - +{ + 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, 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. + 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; +} + +/* + * 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; +} -/* Checks the discriminant of the curve. - * y^2 + x*y = x^3 + a*x^2 + b is an elliptic curve <=> b != 0 (mod p) +/* + * 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; - 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: - if (ctx != NULL) - BN_CTX_end(ctx); - if (new_ctx != NULL) - BN_CTX_free(new_ctx); - return ret; - } +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) - { - point->X = BN_new(); - point->Y = BN_new(); - point->Z = BN_new(); - - if(!point->X || !point->Y || !point->Z) - { - if(point->X) BN_free(point->X); - if(point->Y) BN_free(point->Y); - if(point->Z) BN_free(point->Z); - return 0; - } - 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; - } - - -/* Set an EC_POINT to the point at infinity. - * A point at infinity is represented by having Z=0. +{ + 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; - } +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 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; - } - - -/* Gets the affine coordinates of an EC_POINT. - * Note that the simple implementation only uses affine coordinates. +/* + * Gets the affine coordinates of an EC_POINT. Note that the simple + * implementation only uses affine coordinates. */ -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; - +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; - } + return ret; +} -/* 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. +/* + * 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; +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 - err: - BN_CTX_end(ctx); - if (new_ctx != NULL) - BN_CTX_free(new_ctx); - return ret; - } + 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; -/* 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); - } + err: + 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); +} 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); - } +{ + 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); +} /* 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); - } - +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. */ -int ec_GF2m_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx) - { - int ret = -1; - BN_CTX *new_ctx = NULL; - 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 *); - - 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; - - if (ctx == NULL) - { - ctx = new_ctx = BN_CTX_new(); - if (ctx == NULL) - return -1; - } - - 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 (ctx) BN_CTX_end(ctx); - if (new_ctx) BN_CTX_free(new_ctx); - return ret; - } +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 (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 + + 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: + BN_CTX_end(ctx); +#ifndef FIPS_MODE + BN_CTX_free(new_ctx); +#endif + return ret; +} /*- * Indicates whether two points are equal. @@ -615,118 +573,428 @@ int ec_GF2m_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_ * 0 equal (in affine coordinates) * 1 not equal */ -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 (EC_POINT_is_at_infinity(group, b)) - return 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_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; + } + if (EC_POINT_is_at_infinity(group, b)) + return 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; + } + +#ifndef FIPS_MODE + if (ctx == NULL) { + ctx = new_ctx = BN_CTX_new(); + if (ctx == NULL) + return -1; + } +#endif + + 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; + + 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) - { - 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; - } +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 + if (point->Z_is_one || EC_POINT_is_at_infinity(group, point)) + 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); - } +#ifndef FIPS_MODE + if (ctx == NULL) { + ctx = new_ctx = BN_CTX_new(); + if (ctx == NULL) + return 0; + } +#endif + BN_CTX_start(ctx); + x = BN_CTX_get(ctx); + y = BN_CTX_get(ctx); + if (y == NULL) + goto err; -/* 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); - } + 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; + + 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_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; +} + +/* 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); +} +/* 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); +} /* 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