/*

 * Copyright (C) 2017 Red Hat, Inc.

 *

 * Author: Nikos Mavrogiannopoulos

 *

 * This file is part of GNUTLS.

 *

 * The GNUTLS library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public License

 * as published by the Free Software Foundation; either version 2.1 of

 * the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>

 *

 */

#include "gnutls_int.h"

#include "int/tls1-prf.h"

#include <nettle/hmac.h>

/*-

 * _gnutls_prf_raw:

 * @mac: the MAC algorithm to use, set to %GNUTLS_MAC_MD5_SHA1 for the TLS1.0 mac

 * @master_size: length of the @master variable.

 * @master: the master secret used in PRF computation

 * @label_size: length of the @label variable.

 * @label: label used in PRF computation, typically a short string.

 * @seed_size: length of the @seed variable.

 * @seed: optional extra data to seed the PRF with.

 * @outsize: size of pre-allocated output buffer to hold the output.

 * @out: pre-allocated buffer to hold the generated data.

 *

 * Apply the TLS Pseudo-Random-Function (PRF) on the master secret

 * and the provided data.

 *

 * Returns: %GNUTLS_E_SUCCESS on success, or an error code.

 -*/

int _gnutls_prf_raw(gnutls_mac_algorithm_t mac, size_t master_size,

        const void *master, size_t label_size, const char *label,

        size_t seed_size, const uint8_t *seed, size_t outsize,

        char *out)

{

  int ret;

  switch (mac) {

  case GNUTLS_MAC_MD5_SHA1:

    tls10_prf(master_size, (uint8_t *)master, label_size, label,

        seed_size, seed, outsize, (uint8_t *)out);

    return 0;

  case GNUTLS_MAC_SHA256: {

    struct hmac_sha256_ctx ctx;

    hmac_sha256_set_key(&ctx, master_size, (uint8_t *)master);

    ret = tls12_prf(&ctx,

        (nettle_hash_update_func *)hmac_sha256_update,

        (nettle_hash_digest_func *)hmac_sha256_digest,

        SHA256_DIGEST_SIZE, label_size, label,

        seed_size, seed, outsize, (uint8_t *)out);

    if (unlikely(ret != 1))

      return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);

    break;

  }

  case GNUTLS_MAC_SHA384: {

    struct hmac_sha384_ctx ctx;

    hmac_sha384_set_key(&ctx, master_size, master);

    ret = tls12_prf(&ctx,

        (nettle_hash_update_func *)hmac_sha384_update,

        (nettle_hash_digest_func *)hmac_sha384_digest,

        SHA384_DIGEST_SIZE, label_size, label,

        seed_size, seed, outsize, (uint8_t *)out);

    if (unlikely(ret != 1))

      return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);

    break;

  }

#if ENABLE_GOST

  case GNUTLS_MAC_STREEBOG_256: {

    struct hmac_streebog256_ctx ctx;

    hmac_streebog256_set_key(&ctx, master_size, master);

    ret = tls12_prf(

      &ctx,

      (nettle_hash_update_func *)hmac_streebog256_update,

      (nettle_hash_digest_func *)hmac_streebog256_digest,

      STREEBOG256_DIGEST_SIZE, label_size, label, seed_size,

      seed, outsize, (uint8_t *)out);

    if (unlikely(ret != 1))

      return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);

    break;

  }

  case GNUTLS_MAC_STREEBOG_512: {

    struct hmac_streebog512_ctx ctx;

    hmac_streebog512_set_key(&ctx, master_size, master);

    ret = tls12_prf(

      &ctx,

      (nettle_hash_update_func *)hmac_streebog512_update,

      (nettle_hash_digest_func *)hmac_streebog512_digest,

      STREEBOG512_DIGEST_SIZE, label_size, label, seed_size,

      seed, outsize, (uint8_t *)out);

    if (unlikely(ret != 1))

      return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);

    break;

  }

#endif

  default:

    gnutls_assert();

    _gnutls_debug_log("unhandled PRF %s\n",

          gnutls_mac_get_name(mac));

    return GNUTLS_E_INVALID_REQUEST;

  }

  return 0;

}