/*
    FreeRTOS V9.0.0rc2 - Copyright (C) 2016 Real Time Engineers Ltd.
    All rights reserved

    VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    This file is part of the FreeRTOS distribution.

    FreeRTOS is free software; you can redistribute it and/or modify it under
    the terms of the GNU General Public License (version 2) as published by the
    Free Software Foundation >>>> AND MODIFIED BY <<<< the FreeRTOS exception.

    ***************************************************************************
    >>!   NOTE: The modification to the GPL is included to allow you to     !<<
    >>!   distribute a combined work that includes FreeRTOS without being   !<<
    >>!   obliged to provide the source code for proprietary components     !<<
    >>!   outside of the FreeRTOS kernel.                                   !<<
    ***************************************************************************

    FreeRTOS 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.  Full license text is available on the following
    link: http://www.freertos.org/a00114.html

    ***************************************************************************
     *                                                                       *
     *    FreeRTOS provides completely free yet professionally developed,    *
     *    robust, strictly quality controlled, supported, and cross          *
     *    platform software that is more than just the market leader, it     *
     *    is the industry's de facto standard.                               *
     *                                                                       *
     *    Help yourself get started quickly while simultaneously helping     *
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     *    tutorial book, reference manual, or both:                          *
     *    http://www.FreeRTOS.org/Documentation                              *
     *                                                                       *
    ***************************************************************************

    http://www.FreeRTOS.org/FAQHelp.html - Having a problem?  Start by reading
    the FAQ page "My application does not run, what could be wrong?".  Have you
    defined configASSERT()?

    http://www.FreeRTOS.org/support - In return for receiving this top quality
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    http://www.FreeRTOS.org/training - Investing in training allows your team to
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    FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
    Ltd, and the world's leading authority on the world's leading RTOS.

    http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
    including FreeRTOS+Trace - an indispensable productivity tool, a DOS
    compatible FAT file system, and our tiny thread aware UDP/IP stack.

    http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
    Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.

    http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
    Integrity Systems ltd. to sell under the OpenRTOS brand.  Low cost OpenRTOS
    licenses offer ticketed support, indemnification and commercial middleware.

    http://www.SafeRTOS.com - High Integrity Systems also provide a safety
    engineered and independently SIL3 certified version for use in safety and
    mission critical applications that require provable dependability.

    1 tab == 4 spaces!
*/

#pragma comment( lib, "ws2_32.lib" )

/* Win32 includes. */
#include <WinSock2.h>

/* wolfSSL includes. */
#include "wolfssl/ssl.h"

/* Standard includes. */
#include <stdint.h>
#include <stdio.h>

/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"

/* This application is using the FreeRTOS Windows simulator, which uses the
FreeRTOS scheduler to schedule FreeRTOS task within the Windows environment.
The Windows envrionment must not be allowed to block any Windows threads that
are running FreeRTOS tasks, unless the FreeRTOS task is running at the FreeRTOS
idle priority.  For simplicity, this demo uses the Windows TCP/IP stack, the
API for which can cause Windows threads to block.  Therefore, any FreeRTOS task
that makes calls to the Windows TCP/IP stack must be assigned the idle prioity.
Note this is only a restriction of the simulated Windows environment - real
FreeRTOS ports do not have this restriction. */
#define sstSECURE_CLIENT_TASK_PRIORITY		( tskIDLE_PRIORITY )

/*-----------------------------------------------------------*/

/*
 * Open, configures and binds the server's TCP socket.
 */
static SOCKET prvOpenServerSocket( void );

/*
 * Prepare the wolfSSL library for use.
 */
static void prvInitialiseWolfSSL( void );

/*
 * The task that implements the client side of the connection.
 */
extern void vSecureTCPClientTask( void *pvParameters );

/*-----------------------------------------------------------*/

/* The wolfSSL context for the server. */
static WOLFSSL_CTX* xWolfSSL_ServerContext = NULL;

/*-----------------------------------------------------------*/

/* See the comments at the top of main.c. */
void vSecureTCPServerTask( void *pvParameters )
{
BaseType_t xReturned;
long lBytes;
uint8_t cReceivedString[ 60 ];
struct sockaddr_in xClient;
int xClientAddressLength = sizeof( struct sockaddr_in );
SOCKET xListeningSocket, xConnectedSocket;
WOLFSSL* xWolfSSL_Object; /* Only one connection is accepted at a time, so only one object is needed at a time. */

	/* Just to prevent compiler warnings. */
	( void ) pvParameters;

	/* Perform the initialisation necessary before wolfSSL can be used. */
	prvInitialiseWolfSSL();
	configASSERT( xWolfSSL_ServerContext );

	/* Attempt to open the socket. */
	xListeningSocket = prvOpenServerSocket();

	/* Now the server socket has been created and the wolfSSL library has been
	initialised, the task that implements the client side can be created. */
	xTaskCreate( vSecureTCPClientTask, "Client", configMINIMAL_STACK_SIZE, NULL, sstSECURE_CLIENT_TASK_PRIORITY, NULL );

	if( xListeningSocket != INVALID_SOCKET )
	{
		for( ;; )
		{
			/* Wait until the client connects. */
			printf( "Waiting for new connection\r\n" );
			xConnectedSocket = accept( xListeningSocket, ( struct sockaddr * ) &xClient, &xClientAddressLength );

			if( xConnectedSocket != INVALID_SOCKET )
			{
				printf( "Connection established\r\n" );

				/* A connection has been accepted by the server.  Create a
				wolfSSL object for use with the newly connected socket. */
				xWolfSSL_Object = NULL;
				xWolfSSL_Object = wolfSSL_new( xWolfSSL_ServerContext );

				if( xWolfSSL_Object != NULL )
				{
					/* Associate the created wolfSSL object with the connected
					socket. */
					xReturned = wolfSSL_set_fd( xWolfSSL_Object, xConnectedSocket );
					configASSERT( xReturned == SSL_SUCCESS );

					do
					{
						/* The next line is the secure equivalent to the
						standard sockets call:
						lBytes = recv( xConnectedSocket, cReceivedString, 50, 0 ); */
						lBytes = wolfSSL_read( xWolfSSL_Object, cReceivedString, sizeof( cReceivedString ) );

						/* Print the received characters. */
						if( lBytes > 0 )
						{
							printf( "Received by the secure server: %s\r\n", cReceivedString );
						}

					} while ( lBytes > 0 );

					/* The connection was closed, close the socket and free the
					wolfSSL object. */
					closesocket( xConnectedSocket );
					wolfSSL_free( xWolfSSL_Object );
					printf( "Connection closed, back to start\r\n\r\n" );
				}
			}
		}
	}
	else
	{
		/* The socket could not be opened. */
		vTaskDelete( NULL );
	}
}
/*-----------------------------------------------------------*/

static SOCKET prvOpenServerSocket( void )
{
WSADATA xWSAData;
WORD wVersionRequested;
struct sockaddr_in xConnection;
SOCKET xSocket = INVALID_SOCKET;

	wVersionRequested = MAKEWORD( 2, 2 );

	/* Prepare to use WinSock. */
	if( WSAStartup( wVersionRequested, &xWSAData ) != 0 )
	{
		fprintf( stderr, "Could not open Windows connection.\n" );
	}
	else
	{
		xSocket = socket( AF_INET, SOCK_STREAM, 0 );
		if( xSocket == INVALID_SOCKET)
		{
			fprintf( stderr, "Could not create socket.\n" );
			WSACleanup();
		}
		else
		{
			/* Zero out the server structure. */
			memset( ( void * ) &xConnection, 0x00, sizeof( struct sockaddr_in ) );

			xConnection.sin_family = AF_INET;
			xConnection.sin_addr.s_addr = inet_addr("127.0.0.1");
			xConnection.sin_port = htons( configTCP_PORT_NUMBER );

			/* Bind the address to the socket. */
			if( bind( xSocket, ( struct sockaddr * ) &xConnection, sizeof( struct sockaddr_in ) ) == -1 )
			{
				fprintf( stderr, "Could not socket to port %d.\n", configTCP_PORT_NUMBER );
				closesocket( xSocket );
				xSocket = INVALID_SOCKET;
				WSACleanup();
			}

			if( listen( xSocket, 20 ) != 0 )
			{
				closesocket( xSocket );
				xSocket = INVALID_SOCKET;
				WSACleanup();
			}
		}
	}

	return xSocket;
}
/*-----------------------------------------------------------*/

static void prvInitialiseWolfSSL( void )
{
int32_t iReturn;

	#ifdef DEBUG_WOLFSSL
	{
		wolfSSL_Debugging_ON();
	}
	#endif

    /* Initialise wolfSSL.  This must be done before any other wolfSSL functions
    are called. */
    wolfSSL_Init();

    /* Attempt to create a context that uses the TLS 1.2 server protocol. */
    xWolfSSL_ServerContext = wolfSSL_CTX_new( wolfTLSv1_2_server_method() );

    if( xWolfSSL_ServerContext != NULL )
    {
        /* Load the CA certificate.  Real applications should ensure that
        wolfSSL_CTX_load_verify_locations() returns SSL_SUCCESS before
		proceeding. */
        iReturn = wolfSSL_CTX_load_verify_locations( xWolfSSL_ServerContext, "ca-cert.pem", 0 );
		configASSERT( iReturn == SSL_SUCCESS );

		iReturn = wolfSSL_CTX_use_certificate_file( xWolfSSL_ServerContext, "server-cert.pem", SSL_FILETYPE_PEM );
		configASSERT( iReturn == SSL_SUCCESS );

		iReturn = wolfSSL_CTX_use_PrivateKey_file( xWolfSSL_ServerContext, "server-key.pem", SSL_FILETYPE_PEM );
		configASSERT( iReturn == SSL_SUCCESS );
    }
}