798 lines
22 KiB
C
798 lines
22 KiB
C
/* crypto/ec/ec2_smpl.c */
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/* ====================================================================
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* Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
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*
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* The Elliptic Curve Public-Key Crypto Library (ECC Code) included
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* herein is developed by SUN MICROSYSTEMS, INC., and is contributed
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* to the OpenSSL project.
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*
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* The ECC Code is licensed pursuant to the OpenSSL open source
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* license provided below.
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*
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* The software is originally written by Sheueling Chang Shantz and
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* Douglas Stebila of Sun Microsystems Laboratories.
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*
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*/
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/* ====================================================================
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* Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* 3. All advertising materials mentioning features or use of this
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* software must display the following acknowledgment:
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* "This product includes software developed by the OpenSSL Project
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* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
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*
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* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
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* endorse or promote products derived from this software without
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* prior written permission. For written permission, please contact
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* openssl-core@openssl.org.
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*
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* 5. Products derived from this software may not be called "OpenSSL"
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* nor may "OpenSSL" appear in their names without prior written
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* permission of the OpenSSL Project.
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*
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* 6. Redistributions of any form whatsoever must retain the following
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* acknowledgment:
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* "This product includes software developed by the OpenSSL Project
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* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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*
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* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
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* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
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* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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* ====================================================================
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*
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* This product includes cryptographic software written by Eric Young
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* (eay@cryptsoft.com). This product includes software written by Tim
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* Hudson (tjh@cryptsoft.com).
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*
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*/
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#include <openssl/err.h>
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#include "ec_lcl.h"
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#ifndef OPENSSL_NO_EC2M
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# ifdef OPENSSL_FIPS
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# include <openssl/fips.h>
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# endif
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const EC_METHOD *EC_GF2m_simple_method(void)
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{
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static const EC_METHOD ret = {
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EC_FLAGS_DEFAULT_OCT,
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NID_X9_62_characteristic_two_field,
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ec_GF2m_simple_group_init,
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ec_GF2m_simple_group_finish,
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ec_GF2m_simple_group_clear_finish,
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ec_GF2m_simple_group_copy,
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ec_GF2m_simple_group_set_curve,
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ec_GF2m_simple_group_get_curve,
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ec_GF2m_simple_group_get_degree,
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ec_GF2m_simple_group_check_discriminant,
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ec_GF2m_simple_point_init,
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ec_GF2m_simple_point_finish,
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ec_GF2m_simple_point_clear_finish,
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ec_GF2m_simple_point_copy,
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ec_GF2m_simple_point_set_to_infinity,
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0 /* set_Jprojective_coordinates_GFp */ ,
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0 /* get_Jprojective_coordinates_GFp */ ,
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ec_GF2m_simple_point_set_affine_coordinates,
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ec_GF2m_simple_point_get_affine_coordinates,
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0, 0, 0,
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ec_GF2m_simple_add,
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ec_GF2m_simple_dbl,
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ec_GF2m_simple_invert,
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ec_GF2m_simple_is_at_infinity,
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ec_GF2m_simple_is_on_curve,
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ec_GF2m_simple_cmp,
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ec_GF2m_simple_make_affine,
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ec_GF2m_simple_points_make_affine,
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/*
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* the following three method functions are defined in ec2_mult.c
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*/
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ec_GF2m_simple_mul,
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ec_GF2m_precompute_mult,
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ec_GF2m_have_precompute_mult,
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ec_GF2m_simple_field_mul,
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ec_GF2m_simple_field_sqr,
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ec_GF2m_simple_field_div,
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0 /* field_encode */ ,
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0 /* field_decode */ ,
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0 /* field_set_to_one */
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};
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# ifdef OPENSSL_FIPS
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if (FIPS_mode())
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return fips_ec_gf2m_simple_method();
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# endif
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return &ret;
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}
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/*
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* Initialize a GF(2^m)-based EC_GROUP structure. Note that all other members
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* are handled by EC_GROUP_new.
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*/
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int ec_GF2m_simple_group_init(EC_GROUP *group)
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{
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BN_init(&group->field);
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BN_init(&group->a);
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BN_init(&group->b);
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return 1;
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}
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/*
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* Free a GF(2^m)-based EC_GROUP structure. Note that all other members are
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* handled by EC_GROUP_free.
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*/
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void ec_GF2m_simple_group_finish(EC_GROUP *group)
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{
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BN_free(&group->field);
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BN_free(&group->a);
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BN_free(&group->b);
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}
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/*
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* Clear and free a GF(2^m)-based EC_GROUP structure. Note that all other
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* members are handled by EC_GROUP_clear_free.
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*/
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void ec_GF2m_simple_group_clear_finish(EC_GROUP *group)
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{
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BN_clear_free(&group->field);
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BN_clear_free(&group->a);
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BN_clear_free(&group->b);
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group->poly[0] = 0;
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group->poly[1] = 0;
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group->poly[2] = 0;
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group->poly[3] = 0;
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group->poly[4] = 0;
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group->poly[5] = -1;
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}
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/*
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* Copy a GF(2^m)-based EC_GROUP structure. Note that all other members are
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* handled by EC_GROUP_copy.
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*/
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int ec_GF2m_simple_group_copy(EC_GROUP *dest, const EC_GROUP *src)
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{
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int i;
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if (!BN_copy(&dest->field, &src->field))
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return 0;
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if (!BN_copy(&dest->a, &src->a))
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return 0;
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if (!BN_copy(&dest->b, &src->b))
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return 0;
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dest->poly[0] = src->poly[0];
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dest->poly[1] = src->poly[1];
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dest->poly[2] = src->poly[2];
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dest->poly[3] = src->poly[3];
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dest->poly[4] = src->poly[4];
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dest->poly[5] = src->poly[5];
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if (bn_wexpand(&dest->a, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2)
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== NULL)
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return 0;
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if (bn_wexpand(&dest->b, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2)
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== NULL)
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return 0;
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for (i = dest->a.top; i < dest->a.dmax; i++)
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dest->a.d[i] = 0;
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for (i = dest->b.top; i < dest->b.dmax; i++)
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dest->b.d[i] = 0;
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return 1;
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}
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/* Set the curve parameters of an EC_GROUP structure. */
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int ec_GF2m_simple_group_set_curve(EC_GROUP *group,
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const BIGNUM *p, const BIGNUM *a,
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const BIGNUM *b, BN_CTX *ctx)
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{
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int ret = 0, i;
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/* group->field */
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if (!BN_copy(&group->field, p))
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goto err;
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i = BN_GF2m_poly2arr(&group->field, group->poly, 6) - 1;
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if ((i != 5) && (i != 3)) {
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ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_SET_CURVE, EC_R_UNSUPPORTED_FIELD);
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goto err;
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}
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/* group->a */
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if (!BN_GF2m_mod_arr(&group->a, a, group->poly))
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goto err;
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if (bn_wexpand(&group->a, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2)
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== NULL)
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goto err;
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for (i = group->a.top; i < group->a.dmax; i++)
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group->a.d[i] = 0;
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/* group->b */
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if (!BN_GF2m_mod_arr(&group->b, b, group->poly))
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goto err;
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if (bn_wexpand(&group->b, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2)
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== NULL)
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goto err;
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for (i = group->b.top; i < group->b.dmax; i++)
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group->b.d[i] = 0;
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ret = 1;
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err:
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return ret;
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}
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/*
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* Get the curve parameters of an EC_GROUP structure. If p, a, or b are NULL
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* then there values will not be set but the method will return with success.
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*/
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int ec_GF2m_simple_group_get_curve(const EC_GROUP *group, BIGNUM *p,
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BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
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{
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int ret = 0;
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if (p != NULL) {
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if (!BN_copy(p, &group->field))
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return 0;
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}
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if (a != NULL) {
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if (!BN_copy(a, &group->a))
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goto err;
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}
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if (b != NULL) {
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if (!BN_copy(b, &group->b))
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goto err;
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}
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ret = 1;
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err:
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return ret;
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}
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/*
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* Gets the degree of the field. For a curve over GF(2^m) this is the value
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* m.
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*/
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int ec_GF2m_simple_group_get_degree(const EC_GROUP *group)
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{
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return BN_num_bits(&group->field) - 1;
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}
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/*
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* Checks the discriminant of the curve. y^2 + x*y = x^3 + a*x^2 + b is an
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* elliptic curve <=> b != 0 (mod p)
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*/
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int ec_GF2m_simple_group_check_discriminant(const EC_GROUP *group,
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BN_CTX *ctx)
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{
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int ret = 0;
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BIGNUM *b;
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BN_CTX *new_ctx = NULL;
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if (ctx == NULL) {
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ctx = new_ctx = BN_CTX_new();
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if (ctx == NULL) {
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ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_CHECK_DISCRIMINANT,
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ERR_R_MALLOC_FAILURE);
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goto err;
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}
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}
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BN_CTX_start(ctx);
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b = BN_CTX_get(ctx);
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if (b == NULL)
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goto err;
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if (!BN_GF2m_mod_arr(b, &group->b, group->poly))
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goto err;
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/*
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* check the discriminant: y^2 + x*y = x^3 + a*x^2 + b is an elliptic
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* curve <=> b != 0 (mod p)
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*/
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if (BN_is_zero(b))
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goto err;
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ret = 1;
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err:
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if (ctx != NULL)
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BN_CTX_end(ctx);
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if (new_ctx != NULL)
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BN_CTX_free(new_ctx);
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return ret;
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}
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/* Initializes an EC_POINT. */
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int ec_GF2m_simple_point_init(EC_POINT *point)
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{
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BN_init(&point->X);
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BN_init(&point->Y);
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BN_init(&point->Z);
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return 1;
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}
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/* Frees an EC_POINT. */
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void ec_GF2m_simple_point_finish(EC_POINT *point)
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{
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BN_free(&point->X);
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BN_free(&point->Y);
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BN_free(&point->Z);
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}
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/* Clears and frees an EC_POINT. */
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void ec_GF2m_simple_point_clear_finish(EC_POINT *point)
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{
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BN_clear_free(&point->X);
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BN_clear_free(&point->Y);
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BN_clear_free(&point->Z);
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point->Z_is_one = 0;
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}
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/*
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* Copy the contents of one EC_POINT into another. Assumes dest is
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* initialized.
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*/
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int ec_GF2m_simple_point_copy(EC_POINT *dest, const EC_POINT *src)
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{
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if (!BN_copy(&dest->X, &src->X))
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return 0;
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if (!BN_copy(&dest->Y, &src->Y))
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return 0;
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if (!BN_copy(&dest->Z, &src->Z))
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return 0;
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dest->Z_is_one = src->Z_is_one;
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return 1;
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}
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/*
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* Set an EC_POINT to the point at infinity. A point at infinity is
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* represented by having Z=0.
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*/
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int ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *group,
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EC_POINT *point)
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{
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point->Z_is_one = 0;
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BN_zero(&point->Z);
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return 1;
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}
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/*
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* Set the coordinates of an EC_POINT using affine coordinates. Note that
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* the simple implementation only uses affine coordinates.
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*/
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int ec_GF2m_simple_point_set_affine_coordinates(const EC_GROUP *group,
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EC_POINT *point,
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const BIGNUM *x,
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const BIGNUM *y, BN_CTX *ctx)
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{
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int ret = 0;
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if (x == NULL || y == NULL) {
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ECerr(EC_F_EC_GF2M_SIMPLE_POINT_SET_AFFINE_COORDINATES,
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ERR_R_PASSED_NULL_PARAMETER);
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return 0;
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}
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if (!BN_copy(&point->X, x))
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goto err;
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BN_set_negative(&point->X, 0);
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if (!BN_copy(&point->Y, y))
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goto err;
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BN_set_negative(&point->Y, 0);
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if (!BN_copy(&point->Z, BN_value_one()))
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goto err;
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BN_set_negative(&point->Z, 0);
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point->Z_is_one = 1;
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ret = 1;
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err:
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return ret;
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}
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/*
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* Gets the affine coordinates of an EC_POINT. Note that the simple
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* implementation only uses affine coordinates.
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*/
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int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *group,
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const EC_POINT *point,
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BIGNUM *x, BIGNUM *y,
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BN_CTX *ctx)
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{
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int ret = 0;
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if (EC_POINT_is_at_infinity(group, point)) {
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ECerr(EC_F_EC_GF2M_SIMPLE_POINT_GET_AFFINE_COORDINATES,
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EC_R_POINT_AT_INFINITY);
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return 0;
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}
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if (BN_cmp(&point->Z, BN_value_one())) {
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ECerr(EC_F_EC_GF2M_SIMPLE_POINT_GET_AFFINE_COORDINATES,
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ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
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return 0;
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}
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if (x != NULL) {
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if (!BN_copy(x, &point->X))
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goto err;
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BN_set_negative(x, 0);
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}
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if (y != NULL) {
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if (!BN_copy(y, &point->Y))
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goto err;
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BN_set_negative(y, 0);
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}
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ret = 1;
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err:
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return ret;
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}
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/*
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* Computes a + b and stores the result in r. r could be a or b, a could be
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* b. Uses algorithm A.10.2 of IEEE P1363.
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*/
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int ec_GF2m_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
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const EC_POINT *b, BN_CTX *ctx)
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{
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BN_CTX *new_ctx = NULL;
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BIGNUM *x0, *y0, *x1, *y1, *x2, *y2, *s, *t;
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int ret = 0;
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if (EC_POINT_is_at_infinity(group, a)) {
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if (!EC_POINT_copy(r, b))
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return 0;
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return 1;
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}
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if (EC_POINT_is_at_infinity(group, b)) {
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if (!EC_POINT_copy(r, a))
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return 0;
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return 1;
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}
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if (ctx == NULL) {
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ctx = new_ctx = BN_CTX_new();
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if (ctx == NULL)
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return 0;
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}
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BN_CTX_start(ctx);
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x0 = BN_CTX_get(ctx);
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y0 = BN_CTX_get(ctx);
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x1 = BN_CTX_get(ctx);
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y1 = BN_CTX_get(ctx);
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x2 = BN_CTX_get(ctx);
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y2 = BN_CTX_get(ctx);
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s = BN_CTX_get(ctx);
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t = BN_CTX_get(ctx);
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if (t == NULL)
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goto err;
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if (a->Z_is_one) {
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if (!BN_copy(x0, &a->X))
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goto err;
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if (!BN_copy(y0, &a->Y))
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goto err;
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} else {
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if (!EC_POINT_get_affine_coordinates_GF2m(group, a, x0, y0, ctx))
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goto err;
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}
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if (b->Z_is_one) {
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if (!BN_copy(x1, &b->X))
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goto err;
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if (!BN_copy(y1, &b->Y))
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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;
|
|
|
|
err:
|
|
BN_CTX_end(ctx);
|
|
if (new_ctx != NULL)
|
|
BN_CTX_free(new_ctx);
|
|
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);
|
|
}
|
|
|
|
/* 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.
|
|
*/
|
|
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;
|
|
}
|
|
|
|
/*-
|
|
* Indicates whether two points are equal.
|
|
* Return values:
|
|
* -1 error
|
|
* 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;
|
|
}
|
|
|
|
/* 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;
|
|
point->Z_is_one = 1;
|
|
|
|
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;
|
|
}
|
|
|
|
/* 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);
|
|
}
|
|
|
|
#endif
|