/* $OpenBSD: ec_oct.c,v 1.8 2021/04/20 17:34:33 tb Exp $ */
/*
 * Originally written by Bodo Moeller for the OpenSSL project.
 */
/* ====================================================================
 * Copyright (c) 1998-2003 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 * Binary polynomial ECC support in OpenSSL originally developed by
 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
 */

#include <string.h>

#include <openssl/opensslconf.h>

#include <openssl/err.h>
#include <openssl/opensslv.h>

#include "ec_lcl.h"

int
EC_POINT_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *point,
    const BIGNUM *x, int y_bit, BN_CTX *ctx)
{
	if (group->meth->point_set_compressed_coordinates == NULL &&
	    !(group->meth->flags & EC_FLAGS_DEFAULT_OCT)) {
		ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
		return 0;
	}
	if (group->meth != point->meth) {
		ECerror(EC_R_INCOMPATIBLE_OBJECTS);
		return 0;
	}
	if (group->meth->flags & EC_FLAGS_DEFAULT_OCT) {
		if (group->meth->field_type == NID_X9_62_prime_field)
			return ec_GFp_simple_set_compressed_coordinates(
			    group, point, x, y_bit, ctx);
		else
#ifdef OPENSSL_NO_EC2M
		{
			ECerror(EC_R_GF2M_NOT_SUPPORTED);
			return 0;
		}
#else
			return ec_GF2m_simple_set_compressed_coordinates(
			    group, point, x, y_bit, ctx);
#endif
	}
	if (!group->meth->point_set_compressed_coordinates(group, point, x,
	    y_bit, ctx))
		return 0;
	if (EC_POINT_is_on_curve(group, point, ctx) <= 0) {
		ECerror(EC_R_POINT_IS_NOT_ON_CURVE);
		return 0;
	}
	return 1;
}

int
EC_POINT_set_compressed_coordinates_GFp(const EC_GROUP *group, EC_POINT *point,
    const BIGNUM *x, int y_bit, BN_CTX *ctx)
{
	return EC_POINT_set_compressed_coordinates(group, point, x, y_bit, ctx);
}

#ifndef OPENSSL_NO_EC2M
int
EC_POINT_set_compressed_coordinates_GF2m(const EC_GROUP *group, EC_POINT *point,
    const BIGNUM *x, int y_bit, BN_CTX *ctx)
{
	return EC_POINT_set_compressed_coordinates(group, point, x, y_bit, ctx);
}
#endif

size_t
EC_POINT_point2oct(const EC_GROUP *group, const EC_POINT *point,
    point_conversion_form_t form,
    unsigned char *buf, size_t len, BN_CTX *ctx)
{
	if (group->meth->point2oct == 0
	    && !(group->meth->flags & EC_FLAGS_DEFAULT_OCT)) {
		ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
		return 0;
	}
	if (group->meth != point->meth) {
		ECerror(EC_R_INCOMPATIBLE_OBJECTS);
		return 0;
	}
	if (group->meth->flags & EC_FLAGS_DEFAULT_OCT) {
		if (group->meth->field_type == NID_X9_62_prime_field)
			return ec_GFp_simple_point2oct(group, point,
			    form, buf, len, ctx);
		else
#ifdef OPENSSL_NO_EC2M
		{
			ECerror(EC_R_GF2M_NOT_SUPPORTED);
			return 0;
		}
#else
			return ec_GF2m_simple_point2oct(group, point,
			    form, buf, len, ctx);
#endif
	}
	return group->meth->point2oct(group, point, form, buf, len, ctx);
}

int
EC_POINT_oct2point(const EC_GROUP *group, EC_POINT *point,
    const unsigned char *buf, size_t len, BN_CTX *ctx)
{
	if (group->meth->oct2point == 0 &&
	    !(group->meth->flags & EC_FLAGS_DEFAULT_OCT)) {
		ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
		return 0;
	}
	if (group->meth != point->meth) {
		ECerror(EC_R_INCOMPATIBLE_OBJECTS);
		return 0;
	}
	if (group->meth->flags & EC_FLAGS_DEFAULT_OCT) {
		if (group->meth->field_type == NID_X9_62_prime_field)
			return ec_GFp_simple_oct2point(group, point,
			    buf, len, ctx);
		else
#ifdef OPENSSL_NO_EC2M
		{
			ECerror(EC_R_GF2M_NOT_SUPPORTED);
			return 0;
		}
#else
			return ec_GF2m_simple_oct2point(group, point,
			    buf, len, ctx);
#endif
	}
	return group->meth->oct2point(group, point, buf, len, ctx);
}
