/***************************************************************************
 * Copyright (c) 2024 Microsoft Corporation 
 * 
 * This program and the accompanying materials are made available under the
 * terms of the MIT License which is available at
 * https://opensource.org/licenses/MIT.
 * 
 * SPDX-License-Identifier: MIT
 **************************************************************************/


/**************************************************************************/
/**************************************************************************/
/**                                                                       */
/** NetX Secure Component                                                 */
/**                                                                       */
/**    Transport Layer Security (TLS)                                     */
/**                                                                       */
/**************************************************************************/
/**************************************************************************/

#define NX_SECURE_SOURCE_CODE

#include "nx_secure_tls.h"

/**************************************************************************/
/*                                                                        */
/*  FUNCTION                                               RELEASE        */
/*                                                                        */
/*    _nx_secure_tls_send_changecipherspec                PORTABLE C      */
/*                                                           6.1          */
/*  AUTHOR                                                                */
/*                                                                        */
/*    Timothy Stapko, Microsoft Corporation                               */
/*                                                                        */
/*  DESCRIPTION                                                           */
/*                                                                        */
/*    This function populates an NX_PACKET with the TLS ChangeCipherSpec  */
/*    message, which indicates that all further TLS records will be       */
/*    encrypted ussing the generated session keys.                        */
/*                                                                        */
/*  INPUT                                                                 */
/*                                                                        */
/*    tls_session                           TLS control block             */
/*    send_packet                           Packet to be filled           */
/*                                                                        */
/*  OUTPUT                                                                */
/*                                                                        */
/*    status                                Completion status             */
/*                                                                        */
/*  CALLS                                                                 */
/*                                                                        */
/*    None                                                                */
/*                                                                        */
/*  CALLED BY                                                             */
/*                                                                        */
/*    _nx_secure_dtls_client_handshake      DTLS client state machine     */
/*    _nx_secure_dtls_server_handshake      DTLS server state machine     */
/*    _nx_secure_tls_client_handshake       TLS client state machine      */
/*    _nx_secure_tls_server_handshake       TLS server state machine      */
/*                                                                        */
/*  RELEASE HISTORY                                                       */
/*                                                                        */
/*    DATE              NAME                      DESCRIPTION             */
/*                                                                        */
/*  05-19-2020     Timothy Stapko           Initial Version 6.0           */
/*  09-30-2020     Timothy Stapko           Modified comment(s),          */
/*                                            resulting in version 6.1    */
/*                                                                        */
/**************************************************************************/
UINT _nx_secure_tls_send_changecipherspec(NX_SECURE_TLS_SESSION *tls_session, NX_PACKET *send_packet)
{

    NX_PARAMETER_NOT_USED(tls_session);

    if (((ULONG)(send_packet -> nx_packet_data_end) - (ULONG)(send_packet -> nx_packet_append_ptr)) < 1u)
    {

        /* Packet buffer is too small to hold random and ID. */
        return(NX_SECURE_TLS_PACKET_BUFFER_TOO_SMALL);
    }

    send_packet -> nx_packet_append_ptr[0] = 0x1;
    send_packet -> nx_packet_append_ptr = send_packet -> nx_packet_append_ptr + 1;
    send_packet -> nx_packet_length = 1;

    return(NX_SUCCESS);
}