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Need help with encryption!! c++/cli

anon001 (45)
Reimplement your calculator to encrypt the communication between the clients and the server. Use symmetric encryption for the messages. Modify your application-level protocol to include the delivery of the secret key at the beginning of the session. The client should encrypt the secret key using asymmetric encryption and send it to the server. Server should decrypt it and then both the client and the server should use it throughout the session.

servermain.cpp
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#include "Server.h"

//Started, not finished UDP server
#using "system.dll"
using namespace System;
using namespace System::IO;
using namespace System::Net;
using namespace System::Net::Sockets;
using namespace System::Text;
using namespace System::Collections;
#include <cstdlib>  //for system("PAUSE")

int main(array<String^>^ argv)
{
	int serverPort = 9999;
	// three possible ways to set the IP address
	// The current IP address of the server computer
	// should be set the same way on the client
	IPAddress^ ipAddress = IPAddress::Parse("127.0.0.1");
	IPEndPoint^ receivePoint = gcnew IPEndPoint(ipAddress, serverPort);

	//Initialize a new instance of the UdpClient class and bind it to the local endpoint.
	UdpClient^ udpClient = gcnew UdpClient(receivePoint);
	//The following IPEndPoint object will allow us to read datagrams sent from any source.
	IPEndPoint^ remoteIpEndPoint = gcnew IPEndPoint(IPAddress::Any, 0);
	while (true)
	{
		Console::WriteLine("Datagram server waiting for packets");
		// Block until a message returns on this socket from a remote host.
		array<Byte>^ receivedBytes = udpClient->Receive(remoteIpEndPoint);
		// receivedData will be input from user example: ( ( 15 / (7 - 
		String^ receivedData = Encoding::ASCII->GetString(receivedBytes);
		
		Console::WriteLine("Packet received:");
		Console::WriteLine("Length: " + receivedBytes->Length);
		Console::WriteLine("Containing: " + receivedData);

		Console::Write("Echo data back to client...");
		udpClient->Connect(remoteIpEndPoint->Address, remoteIpEndPoint->Port);
		// result 5
		udpClient->Send(receivedBytes, receivedBytes->Length);
		Console::WriteLine("Packet sent.");
	}

}

server.h
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#ifndef SERVER_H
#define SERVER_H

using namespace System;
using namespace System::Collections;

ref class Calculator
{
public:
	// constructor
	Calculator() {}

	// member functions
	void parseString(String^);
	void reversePolishNotation(Queue^);
	Double calculateFunction();

private:
	// variables
	Queue^ inputQueue = gcnew Queue;
	Queue^ secondQueue = gcnew Queue;
	Queue^ thirdQueue = gcnew Queue;
	Stack^ stack1 = gcnew Stack;
	Stack^ stack2 = gcnew Stack;
};
#endif

server.cpp
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#include "Server.h"

// define your functions here
//System::Void Problem3Server::Form1::convertToInfix(Queue^ parQueue)


//checks for spaces & parses the string
void Calculator::parseString(String^ astr)
{
	String^ currentindex = "";
	for (int i = 0; i < astr->Length; i++)
	{
		while (Convert::ToString(astr[i]) != " ")
		{
			currentindex += astr[i];
			//inputQueue->Enqueue();
			i += 1;

			if (i > astr->Length - 1)
			{
				break;
			}
		}

		inputQueue->Enqueue(currentindex);
		currentindex = "";
	}
}

//converts infix to rpn
void Calculator:: reversePolishNotation(Queue^ inputQueue)
{
	String^ token;

	while (inputQueue->Count != 0)
	{
		token = Convert::ToString(inputQueue->Dequeue());

		if (token != "+" && token != "-" && token != "*" && token != "/" && token != "(" && token != ")")
		{
			thirdQueue->Enqueue(token);
		}
		if (token == "+" || token == "-" || token == "*" || token == "/")
		{
			while ((stack1->Count != 0 && (((token == "-" || token == "+") && (stack1->Peek() == "/" || stack1->Peek() == "*"))
				|| ((token == "-" || token == "+") && (stack1->Peek() == "-" || stack1->Peek() == "+"))
				|| ((token == "*" || token == "/") && (stack1->Peek() == "*" || stack1->Peek() == "/")))
				&& (stack1->Peek() != "(")))
			{
				thirdQueue->Enqueue(stack1->Pop());

			}

			stack1->Push(token);
		}


		if (token == "(")
		{
			stack1->Push(token);
		}


		if (token == ")")
		{
			String^ idx = Convert::ToString(stack1->Pop());
			while (idx != "(")//stack1->Peek() != "(")
			{
				thirdQueue->Enqueue(idx);
				idx = Convert::ToString(stack1->Pop());
			}
		}
	}

	if (inputQueue->Count == 0)
	{
		while (stack1->Count != 0)
		{
			thirdQueue->Enqueue(stack1->Pop());

		}
	}
}

//calculates function
Double Calculator::calculateFunction()
{
	Double first = 0;
	Double second = 0;

	String^ character = Convert::ToString(thirdQueue->Dequeue());

	// while parQueue is not empty

	while (character != "") //queue2->Count != 0)
	{

		if (character == "+")//queue2->Peek() == "+")

		{

			first = Convert::ToDouble(stack2->Pop());

			second = Convert::ToDouble(stack2->Pop());

			// perform addition on the top two popped elements on the stack

			stack2->Push(first + second);

			// dequeue "+"

			// queue2->Dequeue();

		}

		else if (character == "-") // queue2->Peek() == "-")

		{

			first = Convert::ToDouble(stack2->Pop());

			second = Convert::ToDouble(stack2->Pop());

			// perform subtraction on the top two popped elements on the stack

			stack2->Push(second - first);

			// dequeue "-"

			//queue2->Dequeue();

		}

		else if (character == "*")//queue2->Peek() == "*")

		{

			first = Convert::ToDouble(stack2->Pop());

			second = Convert::ToDouble(stack2->Pop());

			// perform multiplication on the top two popped elements on the stack

			stack2->Push(first * second);

			// dequeue "*"

			//queue2->Dequeue();

		}

		else if (character == "/")//queue2->Peek() == "/")

		{

			first = Convert::ToDouble(stack2->Pop());

			second = Convert::ToDouble(stack2->Pop());



			// perform division on the top two popped elements on the stack

			stack2->Push(second / first);

			// dequeue "/"

			//queue2->Dequeue();

		}

		else

		{
			stack2->Push(character);// queue2->Dequeue());

		}

		if (thirdQueue->Count != 0)
			character = Convert::ToString(thirdQueue->Dequeue());
		else
			break;
	}



	Double result = Convert::ToDouble(stack2->Pop());



	return result;
}
Last edited on
anon001 (45)
client (Form1.cpp)

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#include "Form1.h"
#include <Windows.h>

using namespace System;
using namespace System::IO;
using namespace Problem1_VS2013Solution;
using namespace System::Collections;

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, char*, int nShowCard)
{
	Application::EnableVisualStyles();
	Application::SetCompatibleTextRenderingDefault(true);

	Application::Run(gcnew Form1);

	return 0;
}

System::Void Problem1_VS2013Solution::Form1::parse(String^ astr)
{
	String^ currentindex = "";
	for (int i = 0; i < astr->Length; i++)
	{
		while (Convert::ToString(astr[i]) != " ")
		{
			currentindex += astr[i];
			//inputQueue->Enqueue();
			i += 1;

			if (i > astr->Length-1)
			{
				break;
			}
		}
		
		inputQueue->Enqueue(currentindex);
		currentindex = "";
	}
}

System::Void Problem1_VS2013Solution::Form1::convertToInfix(Queue^ parQueue)
{
	String^ token;

	while (parQueue->Count != 0)
	{
		token = Convert::ToString(parQueue->Dequeue());

		if (token != "+" && token != "-" && token != "*" && token != "/" && token != "(" && token != ")")
		{
			queue2->Enqueue(token);
		}
		if (token == "+" || token == "-" || token == "*" || token == "/")
		{
			while ((stack1->Count != 0 && (((token == "-" || token == "+") && (stack1->Peek() == "/" || stack1->Peek() == "*"))
				|| ((token == "-" || token == "+") && (stack1->Peek() == "-" || stack1->Peek() == "+"))
				|| ((token == "*" || token == "/") && (stack1->Peek() == "*" || stack1->Peek() == "/")))
				&& (stack1->Peek() != "(")))
			{
				queue2->Enqueue(stack1->Pop());

			}

			stack1->Push(token);
		}


		if (token == "(")
		{
			stack1->Push(token);
		}


		if (token == ")")
		{
			String^ idx = Convert::ToString(stack1->Pop());
			while (idx != "(")//stack1->Peek() != "(")
			{
				queue2->Enqueue(idx);
				idx = Convert::ToString(stack1->Pop());
			}
		}
	}

	if (parQueue->Count == 0)
	{
		while (stack1->Count != 0)
		{
			queue2->Enqueue(stack1->Pop());

		}
	}
}

System::Double Problem1_VS2013Solution::Form1::calculateFunction()
{
	// checks if checked box is not checked
	/*
	if (!(InfixRpn->Checked))

	{

		// while the queue is not empty

		while (queue2->Count != 0)

		{

			// dequeues "(" and ")"

			if (queue2->Peek() == "(" || queue2->Peek() == ")")

			{

				queue2->Dequeue();

			}



			// adds each element in the queue as long as its not "(" and ")"

			parQueue->Enqueue(queue2->Dequeue());

		}

	}*/



	Double first = 0;
	Double second = 0;

	String^ character = Convert::ToString(queue2->Dequeue());

	// while parQueue is not empty

	while (character != "") //queue2->Count != 0)
	{

		if (character == "+")//queue2->Peek() == "+")

		{

			first = Convert::ToDouble(stack2->Pop());

			second = Convert::ToDouble(stack2->Pop());

			// perform addition on the top two popped elements on the stack

			stack2->Push(first + second);

			// dequeue "+"

			// queue2->Dequeue();

		}

		else if (character == "-") // queue2->Peek() == "-")

		{

			first = Convert::ToDouble(stack2->Pop());

			second = Convert::ToDouble(stack2->Pop());

			// perform subtraction on the top two popped elements on the stack

			stack2->Push(second - first);

			// dequeue "-"

			//queue2->Dequeue();

		}

		else if (character == "*")//queue2->Peek() == "*")

		{

			first = Convert::ToDouble(stack2->Pop());

			second = Convert::ToDouble(stack2->Pop());

			// perform multiplication on the top two popped elements on the stack

			stack2->Push(first * second);

			// dequeue "*"

			//queue2->Dequeue();

		}

		else if (character == "/")//queue2->Peek() == "/")

		{

			first = Convert::ToDouble(stack2->Pop());

			second = Convert::ToDouble(stack2->Pop());



			// perform division on the top two popped elements on the stack

			stack2->Push(second / first);

			// dequeue "/"

			//queue2->Dequeue();

		}

		else

		{
			stack2->Push(character);// queue2->Dequeue());

		}

		if (queue2->Count != 0)
			character = Convert::ToString(queue2->Dequeue());
		else
			break;
	}



	Double result = Convert::ToDouble(stack2->Pop());



	return result;
}
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