/* $OpenBSD: gostr341001_key.c,v 1.9 2021/04/20 17:16:38 tb Exp $ */

/*

 * Copyright (c) 2014 Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>

 * Copyright (c) 2005-2006 Cryptocom LTD

 *

 * 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.

 * ====================================================================

 */

#include <string.h>

#include <openssl/opensslconf.h>

#ifndef OPENSSL_NO_GOST

#include <openssl/bn.h>

#include <openssl/err.h>

#include <openssl/gost.h>

#include <openssl/objects.h>

#include "gost_locl.h"

struct gost_key_st {

  EC_GROUP *group;

  EC_POINT *pub_key;

  BIGNUM   *priv_key;

  int references;

  int digest_nid;

};

GOST_KEY *

GOST_KEY_new(void)

{

  GOST_KEY *ret;

  ret = malloc(sizeof(GOST_KEY));

  if (ret == NULL) {

    GOSTerror(ERR_R_MALLOC_FAILURE);

    return (NULL);

  }

  ret->group = NULL;

  ret->pub_key = NULL;

  ret->priv_key = NULL;

  ret->references = 1;

  ret->digest_nid = NID_undef;

  return (ret);

}

void

GOST_KEY_free(GOST_KEY *r)

{

  int i;

  if (r == NULL)

    return;

  i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_EC);

  if (i > 0)

    return;

  EC_GROUP_free(r->group);

  EC_POINT_free(r->pub_key);

  BN_clear_free(r->priv_key);

  freezero(r, sizeof(GOST_KEY));

}

int

GOST_KEY_check_key(const GOST_KEY *key)

{

  int ok = 0;

  BN_CTX *ctx = NULL;

  BIGNUM *order = NULL;

  EC_POINT *point = NULL;

  if (key == NULL || key->group == NULL || key->pub_key == NULL) {

    GOSTerror(ERR_R_PASSED_NULL_PARAMETER);

    return 0;

  }

  if (EC_POINT_is_at_infinity(key->group, key->pub_key) != 0) {

    GOSTerror(EC_R_POINT_AT_INFINITY);

    goto err;

  }

  if ((ctx = BN_CTX_new()) == NULL)

    goto err;

  if ((point = EC_POINT_new(key->group)) == NULL)

    goto err;

  /* testing whether the pub_key is on the elliptic curve */

  if (EC_POINT_is_on_curve(key->group, key->pub_key, ctx) == 0) {

    GOSTerror(EC_R_POINT_IS_NOT_ON_CURVE);

    goto err;

  }

  /* testing whether pub_key * order is the point at infinity */

  if ((order = BN_new()) == NULL)

    goto err;

  if (EC_GROUP_get_order(key->group, order, ctx) == 0) {

    GOSTerror(EC_R_INVALID_GROUP_ORDER);

    goto err;

  }

  if (EC_POINT_mul(key->group, point, NULL, key->pub_key, order,

      ctx) == 0) {

    GOSTerror(ERR_R_EC_LIB);

    goto err;

  }

  if (EC_POINT_is_at_infinity(key->group, point) == 0) {

    GOSTerror(EC_R_WRONG_ORDER);

    goto err;

  }

  /*

   * in case the priv_key is present : check if generator * priv_key ==

   * pub_key

   */

  if (key->priv_key != NULL) {

    if (BN_cmp(key->priv_key, order) >= 0) {

      GOSTerror(EC_R_WRONG_ORDER);

      goto err;

    }

    if (EC_POINT_mul(key->group, point, key->priv_key, NULL, NULL,

        ctx) == 0) {

      GOSTerror(ERR_R_EC_LIB);

      goto err;

    }

    if (EC_POINT_cmp(key->group, point, key->pub_key, ctx) != 0) {

      GOSTerror(EC_R_INVALID_PRIVATE_KEY);

      goto err;

    }

  }

  ok = 1;

err:

  BN_free(order);

  BN_CTX_free(ctx);

  EC_POINT_free(point);

  return (ok);

}

int

GOST_KEY_set_public_key_affine_coordinates(GOST_KEY *key, BIGNUM *x, BIGNUM *y)

{

  BN_CTX *ctx = NULL;

  BIGNUM *tx, *ty;

  EC_POINT *point = NULL;

  int ok = 0;

  if (key == NULL || key->group == NULL || x == NULL || y == NULL) {

    GOSTerror(ERR_R_PASSED_NULL_PARAMETER);

    return 0;

  }

  ctx = BN_CTX_new();

  if (ctx == NULL)

    goto err;

  point = EC_POINT_new(key->group);

  if (point == NULL)

    goto err;

  if ((tx = BN_CTX_get(ctx)) == NULL)

    goto err;

  if ((ty = BN_CTX_get(ctx)) == NULL)

    goto err;

  if (EC_POINT_set_affine_coordinates(key->group, point, x, y,

      ctx) == 0)

    goto err;

  if (EC_POINT_get_affine_coordinates(key->group, point, tx, ty,

      ctx) == 0)

    goto err;

  /*

   * Check if retrieved coordinates match originals: if not, values are

   * out of range.

   */

  if (BN_cmp(x, tx) != 0 || BN_cmp(y, ty) != 0) {

    GOSTerror(EC_R_COORDINATES_OUT_OF_RANGE);

    goto err;

  }

  if (GOST_KEY_set_public_key(key, point) == 0)

    goto err;

  if (GOST_KEY_check_key(key) == 0)

    goto err;

  ok = 1;

err:

  EC_POINT_free(point);

  BN_CTX_free(ctx);

  return ok;

}

const EC_GROUP *

GOST_KEY_get0_group(const GOST_KEY *key)

{

  return key->group;

}

int

GOST_KEY_set_group(GOST_KEY *key, const EC_GROUP *group)

{

  EC_GROUP_free(key->group);

  key->group = EC_GROUP_dup(group);

  return (key->group == NULL) ? 0 : 1;

}

const BIGNUM *

GOST_KEY_get0_private_key(const GOST_KEY *key)

{

  return key->priv_key;

}

int

GOST_KEY_set_private_key(GOST_KEY *key, const BIGNUM *priv_key)

{

  BN_clear_free(key->priv_key);

  key->priv_key = BN_dup(priv_key);

  return (key->priv_key == NULL) ? 0 : 1;

}

const EC_POINT *

GOST_KEY_get0_public_key(const GOST_KEY *key)

{

  return key->pub_key;

}

int

GOST_KEY_set_public_key(GOST_KEY *key, const EC_POINT *pub_key)

{

  EC_POINT_free(key->pub_key);

  key->pub_key = EC_POINT_dup(pub_key, key->group);

  return (key->pub_key == NULL) ? 0 : 1;

}

int

GOST_KEY_get_digest(const GOST_KEY *key)

{

  return key->digest_nid;

}

int

GOST_KEY_set_digest(GOST_KEY *key, int digest_nid)

{

  if (digest_nid == NID_id_GostR3411_94_CryptoProParamSet ||

      digest_nid == NID_id_tc26_gost3411_2012_256 ||

      digest_nid == NID_id_tc26_gost3411_2012_512) {

    key->digest_nid = digest_nid;

    return 1;

  }

  return 0;

}

size_t

GOST_KEY_get_size(const GOST_KEY *r)

{

  int i;

  BIGNUM *order = NULL;

  const EC_GROUP *group;

  if (r == NULL)

    return 0;

  group = GOST_KEY_get0_group(r);

  if (group == NULL)

    return 0;

  if ((order = BN_new()) == NULL)

    return 0;

  if (EC_GROUP_get_order(group, order, NULL) == 0) {

    BN_clear_free(order);

    return 0;

  }

  i = BN_num_bytes(order);

  BN_clear_free(order);

  return (i);

}

#endif