/* $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);

}