/*******************************************************************************
    OpenAirInterface
    Copyright(c) 1999 - 2014 Eurecom

    OpenAirInterface is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.


    OpenAirInterface 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with OpenAirInterface.The full GNU General Public License is
   included in this distribution in the file called "COPYING". If not,
   see <http://www.gnu.org/licenses/>.

  Contact Information
  OpenAirInterface Admin: openair_admin@eurecom.fr
  OpenAirInterface Tech : openair_tech@eurecom.fr
  OpenAirInterface Dev  : openair4g-devel@eurecom.fr

  Address      : Eurecom, Compus SophiaTech 450, route des chappes, 06451 Biot, France.

 *******************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>


#include "TLVEncoder.h"
#include "TLVDecoder.h"
#include "AuthenticationRequest.h"

int decode_authentication_request(authentication_request_msg *authentication_request, uint8_t *buffer, uint32_t len)
{
  uint32_t decoded = 0;
  int decoded_result = 0;

  // Check if we got a NULL pointer and if buffer length is >= minimum length expected for the message.
  CHECK_PDU_POINTER_AND_LENGTH_DECODER(buffer, AUTHENTICATION_REQUEST_MINIMUM_LENGTH, len);

  /* Decoding mandatory fields */
  if ((decoded_result = decode_u8_nas_key_set_identifier(&authentication_request->naskeysetidentifierasme, 0, *(buffer + decoded) >> 4, len - decoded)) < 0)
    return decoded_result;

  decoded++;

  if ((decoded_result = decode_authentication_parameter_rand(&authentication_request->authenticationparameterrand, 0, buffer + decoded, len - decoded)) < 0)
    return decoded_result;
  else
    decoded += decoded_result;

  if ((decoded_result = decode_authentication_parameter_autn(&authentication_request->authenticationparameterautn, 0, buffer + decoded, len - decoded)) < 0)
    return decoded_result;
  else
    decoded += decoded_result;

  return decoded;
}

int encode_authentication_request(authentication_request_msg *authentication_request, uint8_t *buffer, uint32_t len)
{
  int encoded = 0;
  int encode_result = 0;

  /* Checking IEI and pointer */
  CHECK_PDU_POINTER_AND_LENGTH_ENCODER(buffer, AUTHENTICATION_REQUEST_MINIMUM_LENGTH, len);

  *(buffer + encoded) = ((encode_u8_nas_key_set_identifier(&authentication_request->naskeysetidentifierasme) & 0x0f) << 4) | 0x00;
  encoded++;

  if ((encode_result =
         encode_authentication_parameter_rand(&authentication_request->authenticationparameterrand,
             0, buffer + encoded, len - encoded)) < 0)        //Return in case of error
    return encode_result;
  else
    encoded += encode_result;

  if ((encode_result =
         encode_authentication_parameter_autn(&authentication_request->authenticationparameterautn,
             0, buffer + encoded, len - encoded)) < 0)        //Return in case of error
    return encode_result;
  else
    encoded += encode_result;

  return encoded;
}