/*

 * Copyright (C) 2017 Red Hat, Inc.

 *

 * Author: Nikos Mavrogiannopoulos

 *

 * This file is part of GnuTLS.

 *

 * The GnuTLS 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/>

 *

 */

/* Internal API functions to be used by extension handlers.

 */

#include "gnutls_int.h"

#include "hello_ext.h"

#include "hello_ext_lib.h"

void _gnutls_hello_ext_default_deinit(gnutls_ext_priv_data_t priv)

{

  gnutls_free(priv);

}

/* When this is used, the deinitialization function must be set to default:

 * _gnutls_hello_ext_default_deinit.

 *

 * This also prevents and errors on duplicate entries.

 */

int _gnutls_hello_ext_set_datum(gnutls_session_t session, extensions_t id,

        const gnutls_datum_t *data)

{

  gnutls_ext_priv_data_t epriv;

  if (_gnutls_hello_ext_get_priv(session, id, &epriv) >= 0)

    return gnutls_assert_val(GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER);

  if (data->size >= UINT16_MAX)

    return gnutls_assert_val(GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER);

  epriv = gnutls_malloc(data->size + 2);

  if (epriv == NULL)

    return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);

  _gnutls_write_uint16(data->size, epriv);

  memcpy(((uint8_t *)epriv) + 2, data->data, data->size);

  _gnutls_hello_ext_set_priv(session, id, epriv);

  return 0;

}

int _gnutls_hello_ext_get_datum(gnutls_session_t session, extensions_t id,

        gnutls_datum_t *data /* constant contents */)

{

  gnutls_ext_priv_data_t epriv;

  int ret;

  ret = _gnutls_hello_ext_get_priv(session, id, &epriv);

  if (ret < 0 || epriv == NULL)

    return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;

  data->size = _gnutls_read_uint16(epriv);

  data->data = ((uint8_t *)epriv) + 2;

  return 0;

}

int _gnutls_hello_ext_get_resumed_datum(

  gnutls_session_t session, extensions_t id,

  gnutls_datum_t *data /* constant contents */)

{

  gnutls_ext_priv_data_t epriv;

  int ret;

  ret = _gnutls_hello_ext_get_resumed_priv(session, id, &epriv);

  if (ret < 0 || epriv == NULL)

    return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;

  data->size = _gnutls_read_uint16(epriv);

  data->data = ((uint8_t *)epriv) + 2;

  return 0;

}

int _gnutls_hello_ext_default_pack(gnutls_ext_priv_data_t epriv,

           gnutls_buffer_st *ps)

{

  size_t size;

  size = _gnutls_read_uint16(epriv);

  return _gnutls_buffer_append_data(ps, epriv, size + 2);

}

int _gnutls_hello_ext_default_unpack(gnutls_buffer_st *ps,

             gnutls_ext_priv_data_t *epriv)

{

  gnutls_datum_t data;

  uint8_t *store;

  int ret;

  ret = _gnutls_buffer_pop_datum_prefix16(ps, &data);

  if (ret < 0)

    return gnutls_assert_val(ret);

  store = gnutls_calloc(1, data.size + 2);

  if (store == NULL)

    return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);

  _gnutls_write_uint16(data.size, store);

  memcpy(store + 2, data.data, data.size);

  *epriv = store;

  return 0;

}