/*

 * Copyright (C) 2017-2018 Free Software Foundation, Inc.

 * Copyright (C) 2018 Red Hat, Inc.

 *

 * Author: Ander Juaristi, 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/>

 *

 */

#include "gnutls_int.h"

#include "tls13/psk_ext_parser.h"

/* Returns GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE when no identities

 * are present, or 0, on success.

 */

int _gnutls13_psk_ext_parser_init(psk_ext_parser_st * p,

          const unsigned char *data, size_t len)

{

  if (!p || !data || !len)

    return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);

  memset(p, 0, sizeof(*p));

  DECR_LEN(len, 2);

  p->identities_len = _gnutls_read_uint16(data);

  data += 2;

  if (p->identities_len == 0)

    return gnutls_assert_val(GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE);

  p->identities_data = (unsigned char *)data;

  DECR_LEN(len, p->identities_len);

  data += p->identities_len;

  DECR_LEN(len, 2);

  p->binders_len = _gnutls_read_uint16(data);

  data += 2;

  p->binders_data = data;

  DECR_LEN(len, p->binders_len);

  return 0;

}

/* Extract PSK identity and move to the next iteration.

 *

 * Returns GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE when no more identities

 * are present, or 0, on success.

 */

int _gnutls13_psk_ext_iter_next_identity(psk_ext_iter_st * iter,

           struct psk_st *psk)

{

  if (iter->identities_len == 0)

    return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;

  DECR_LEN(iter->identities_len, 2);

  psk->identity.size = _gnutls_read_uint16(iter->identities_data);

  if (psk->identity.size == 0)

    return gnutls_assert_val(GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER);

  iter->identities_data += 2;

  psk->identity.data = (void *)iter->identities_data;

  DECR_LEN(iter->identities_len, psk->identity.size);

  iter->identities_data += psk->identity.size;

  DECR_LEN(iter->identities_len, 4);

  psk->ob_ticket_age = _gnutls_read_uint32(iter->identities_data);

  iter->identities_data += 4;

  return 0;

}

/* Extract PSK binder and move to the next iteration.

 *

 * Returns GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE when no more identities

 * are present, or 0, on success.

 */

int _gnutls13_psk_ext_iter_next_binder(psk_ext_iter_st * iter,

               gnutls_datum_t * binder)

{

  if (iter->binders_len == 0)

    return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;

  DECR_LEN(iter->binders_len, 1);

  binder->size = *iter->binders_data;

  if (binder->size == 0)

    return gnutls_assert_val(GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER);

  iter->binders_data++;

  binder->data = (uint8_t *) iter->binders_data;

  DECR_LEN(iter->binders_len, binder->size);

  iter->binders_data += binder->size;

  return 0;

}