/* ====================================================================

 * 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 ECDH software is originally written by Douglas Stebila of

 * Sun Microsystems Laboratories.

 *

 */

/* ====================================================================

 * Copyright (c) 2000-2002 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

 *    licensing@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). */

#include <openssl/ecdh.h>

#include <string.h>

#include <openssl/ec.h>

#include <openssl/ec_key.h>

#include <openssl/err.h>

#include <openssl/mem.h>

#include "../../internal.h"

#include "../ec/internal.h"

#include "../service_indicator/internal.h"

int ECDH_compute_key_fips(uint8_t *out, size_t out_len, const EC_POINT *pub_key,

                          const EC_KEY *priv_key) {

  boringssl_ensure_ecc_self_test();

  if (priv_key->priv_key == NULL) {

    OPENSSL_PUT_ERROR(ECDH, ECDH_R_NO_PRIVATE_VALUE);

    return 0;

  }

  const EC_SCALAR *const priv = &priv_key->priv_key->scalar;

  const EC_GROUP *const group = EC_KEY_get0_group(priv_key);

  if (EC_GROUP_cmp(group, pub_key->group, NULL) != 0) {

    OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS);

    return 0;

  }

  EC_JACOBIAN shared_point;

  uint8_t buf[EC_MAX_BYTES];

  size_t buflen;

  if (!ec_point_mul_scalar(group, &shared_point, &pub_key->raw, priv) ||

      !ec_get_x_coordinate_as_bytes(group, buf, &buflen, sizeof(buf),

                                    &shared_point)) {

    OPENSSL_PUT_ERROR(ECDH, ECDH_R_POINT_ARITHMETIC_FAILURE);

    return 0;

  }

  FIPS_service_indicator_lock_state();

  SHA256_CTX ctx;

  SHA512_CTX ctx_512;

  switch (out_len) {

    case SHA224_DIGEST_LENGTH:

      BCM_sha224_init(&ctx);

      BCM_sha224_update(&ctx, buf, buflen);

      BCM_sha224_final(out, &ctx);

      break;

    case SHA256_DIGEST_LENGTH:

      BCM_sha256_init(&ctx);

      BCM_sha256_update(&ctx, buf, buflen);

      BCM_sha256_final(out, &ctx);

      break;

    case SHA384_DIGEST_LENGTH:

      BCM_sha384_init(&ctx_512);

      BCM_sha384_update(&ctx_512, buf, buflen);

      BCM_sha384_final(out, &ctx_512);

      break;

    case SHA512_DIGEST_LENGTH:

      BCM_sha512_init(&ctx_512);

      BCM_sha512_update(&ctx_512, buf, buflen);

      BCM_sha512_final(out, &ctx_512);

      break;

    default:

      OPENSSL_PUT_ERROR(ECDH, ECDH_R_UNKNOWN_DIGEST_LENGTH);

      FIPS_service_indicator_unlock_state();

      return 0;

  }

  FIPS_service_indicator_unlock_state();

  ECDH_verify_service_indicator(priv_key);

  return 1;

}