Click here to Skip to main content
       

C#

 
GeneralRe: Methods, Parameters, Arguments… Oh my! PinmemberWidmarkRob12-May-13 10:40 
GeneralRe: Methods, Parameters, Arguments… Oh my! PinmvpRichard MacCutchan12-May-13 21:09 
GeneralRe: Methods, Parameters, Arguments… Oh my! PinmemberWidmarkRob12-May-13 21:40 
GeneralRe: Methods, Parameters, Arguments… Oh my! PinmvpRichard MacCutchan12-May-13 23:16 
GeneralRe: Methods, Parameters, Arguments… Oh my! PinmemberWidmarkRob13-May-13 2:21 
GeneralRe: Methods, Parameters, Arguments… Oh my! PinmentorKeith Barrow12-May-13 23:38 
GeneralRe: Methods, Parameters, Arguments… Oh my! PinmvpRichard MacCutchan12-May-13 23:56 
GeneralRe: Methods, Parameters, Arguments… Oh my! PinprotectorPete O'Hanlon13-May-13 0:36 
GeneralRe: Methods, Parameters, Arguments… Oh my! PinmvpRichard MacCutchan13-May-13 0:38 
QuestionJust a simple question PinmemberJesús Frías12-May-13 6:13 
AnswerRe: Just a simple question PinmvpAbhinav S12-May-13 6:19 
QuestionRE: Custom Login to a secure Page on an external site. Pinmemberkhali7811-May-13 19:29 
AnswerRe: RE: Custom Login to a secure Page on an external site. PinmvpRichard MacCutchan11-May-13 21:26 
Questionsockets + Cryptography PinmemberMember 997361610-May-13 14:07 
Hi, I want to realise a Cleint/Server chat app that respects this:
 
1- Server connects to client;
2- server send "Hello" to client;
3- cleint responses with "Hello, ok";
4- server generates RSA Key and send public key to cleint;
5- client select a random algorithm from DES, AES(128, 192, 256) and sends it to the server;
6- server sends "GENERATE FIRST KEY" to client;
7- cleint generate a key with a size that dependse on the algorithm choosen in step 5, and encrypt it using the public key;
8- server decrypts the key;
 
Now the server and client can communicate using the shared key, and to make it more secure, after 5 min server send "NEXT KEY", to generate another key
 

Untill now I just can chat between client and server without encrypt messages, and this is my code
 

Server:
 
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.Threading;
 
namespace Server___Tutorial
{
    public partial class Form1 : Form
    {
        int i;
        TcpListener server = new TcpListener(IPAddress.Any, 1980); // Creates a TCP Listener To Listen to Any IPAddress trying to connect to the program with port 1980
        NetworkStream stream; //Creats a NetworkStream (used for sending and receiving data)
        TcpClient client; // Creates a TCP Client
        byte[] datalength = new byte[4]; // creates a new byte with length 4 ( used for receivng data's lenght)
       
        public Form1()
        {
            InitializeComponent();
        }
 
   
        public void ServerReceive()
        {
            stream = client.GetStream(); //Gets The Stream of The Connection
            new Thread(() => // Thread (like Timer)
            {
                while ((i = stream.Read(datalength, 0, 4)) != 0)//Keeps Trying to Receive the Size of the Message or Data
                {
                    // how to make a byte E.X byte[] examlpe = new byte[the size of the byte here] , i used BitConverter.ToInt32(datalength,0) cuz i received the length of the data in byte called datalength :D
                    byte[] data = new byte[BitConverter.ToInt32(datalength, 0)]; // Creates a Byte for the data to be Received On
                    stream.Read(data, 0, data.Length); //Receives The Real Data not the Size
                    this.Invoke((MethodInvoker)delegate // To Write the Received data
                    {
                        txtLog.Text += System.Environment.NewLine + "Client : " + Encoding.Default.GetString(data); // Encoding.Default.GetString(data); Converts Bytes Received to String
                    });
                }
            }).Start(); // Start the Thread
 
        }
       
 
       
        public void ServerSend(string msg)
        {
            stream = client.GetStream(); //Gets The Stream of The Connection
            byte[] data; // creates a new byte without mentioning the size of it cuz its a byte used for sending
            data = Encoding.Default.GetBytes(msg); // put the msg in the byte ( it automaticly uses the size of the msg )
            int length = data.Length; // Gets the length of the byte data
            byte[] datalength = new byte[4]; // Creates a new byte with length of 4
            datalength = BitConverter.GetBytes(length); //put the length in a byte to send it
            stream.Write(datalength, 0, 4); // sends the data's length
            stream.Write(data, 0, data.Length); //Sends the real data
        }
 
        private void btnListen_Click(object sender, EventArgs e)
        {
            server.Start(); // Starts Listening to Any IPAddress trying to connect to the program with port 1980
            MessageBox.Show("Waiting For Connection");
            new Thread(() => // Creates a New Thread (like a timer)
                {
                    client = server.AcceptTcpClient(); //Waits for the Client To Connect
                    MessageBox.Show("Connected To Client");
                    if (client.Connected) // If you are connected
                    {
                        ServerReceive(); //Start Receiving
                    }
                }).Start();
        }
 
        private void btnSend_Click(object sender, EventArgs e)
        {
            if (client.Connected) // if the client is connected
            {
                ServerSend(txtSend.Text); // uses the Function ClientSend and the msg as txtSend.Text
            }
        }
 
       
    }
}
 
Client:
 
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.Threading;
 
namespace Client
{
    public partial class Form1 : Form
    {
        int i;
        TcpClient client; // Creates a TCP Client
        NetworkStream stream; //Creats a NetworkStream (used for sending and receiving data)
        byte[] datalength = new byte[4]; // creates a new byte with length 4 ( used for receivng data's lenght)
 
        public Form1()
        {
            InitializeComponent();
        }
 
        private void btnConnect_Click(object sender, EventArgs e)
        {
            try
            {
                client = new TcpClient("127.0.0.1", 1980); //Trys to Connect
                ClientReceive(); //Starts Receiving When Connected
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message); // Error handler :D
            }
        }
 
        public void ClientReceive()
        {
           
            stream = client.GetStream(); //Gets The Stream of The Connection
            new Thread(() => // Thread (like Timer)
            {
                while ((i = stream.Read(datalength, 0, 4)) != 0)//Keeps Trying to Receive the Size of the Message or Data
                {
                    // how to make a byte E.X byte[] examlpe = new byte[the size of the byte here] , i used BitConverter.ToInt32(datalength,0) cuz i received the length of the data in byte called datalength :D
                    byte[] data = new byte[BitConverter.ToInt32(datalength,0)]; // Creates a Byte for the data to be Received On
                    stream.Read(data, 0, data.Length); //Receives The Real Data not the Size
                    this.Invoke((MethodInvoker)delegate // To Write the Received data
                    {
                        txtLog.Text += System.Environment.NewLine + "Server : " + Encoding.Default.GetString(data); // Encoding.Default.GetString(data); Converts Bytes Received to String
                    });  
                }
            }).Start(); // Start the Thread
        }
 
        public void ClientSend(string msg)
        {
            stream = client.GetStream(); //Gets The Stream of The Connection
            byte[] data; // creates a new byte without mentioning the size of it cuz its a byte used for sending
            data = Encoding.Default.GetBytes(msg); // put the msg in the byte ( it automaticly uses the size of the msg )
            int length = data.Length; // Gets the length of the byte data
            byte[] datalength = new byte[4]; // Creates a new byte with length of 4
            datalength = BitConverter.GetBytes(length); //put the length in a byte to send it
            stream.Write(datalength, 0, 4); // sends the data's length
            stream.Write(data, 0, data.Length); //Sends the real data
        }
 
        private void btnSend_Click(object sender, EventArgs e)
        {
            if (client.Connected) // if the client is connected
            {
                ClientSend(txtSend.Text); // uses the Function ClientSend and the msg as txtSend.Text
            }
        }
 
    }
}
 
I also have AES, DES and RSA classes, but I don't know how to tell if a message is a key or just a normal message...
 

Thank you
SuggestionRe: sockets + Cryptography PinmemberAmitosh Swain10-May-13 15:35 
GeneralRe: sockets + Cryptography PinmemberMember 997361610-May-13 22:50 
GeneralRe: sockets + Cryptography PinmemberAmitosh Swain11-May-13 16:38 
Questionwhats the best practice to save service data? Pinmemberneodeaths10-May-13 9:18 
AnswerRe: whats the best practice to save service data? PinmvpDave Kreskowiak10-May-13 10:49 
AnswerRe: whats the best practice to save service data? PinmvpEddy Vluggen11-May-13 3:30 
QuestionProperties vs Methods Opinions sought PinmentorKeith Barrow10-May-13 4:22 
SuggestionRe: Properties vs Methods Opinions sought PinprofessionalRichard Deeming10-May-13 5:16 
GeneralRe: Properties vs Methods Opinions sought PinmentorKeith Barrow10-May-13 5:37 
GeneralRe: Properties vs Methods Opinions sought Pinmemberjschell10-May-13 7:58 
AnswerRe: Properties vs Methods Opinions sought Pinmemberjschell10-May-13 7:50 
GeneralRe: Properties vs Methods Opinions sought PinmemberEnnis Ray Lynch, Jr.10-May-13 8:41 
GeneralRe: Properties vs Methods Opinions sought Pinmemberjschell13-May-13 7:58 
AnswerRe: Properties vs Methods Opinions sought PinprofessionalPIEBALDconsult10-May-13 18:32 
GeneralPracticing Code Logic PinmemberWidmarkRob10-May-13 3:24 
GeneralRe: Practicing Code Logic PinmvpRichard MacCutchan10-May-13 3:48 
Questionxmpp PinmemberMember 1004242210-May-13 2:20 
AnswerRe: xmpp PinprotectorPete O'Hanlon10-May-13 2:34 
AnswerRe: xmpp PinmvpRichard MacCutchan10-May-13 3:44 
QuestionAbout xmpp n bosh server PinmemberMember 1004242210-May-13 1:46 
AnswerRe: About xmpp n bosh server PinprotectorPete O'Hanlon10-May-13 2:13 
QuestionExport to PST PinmemberJD869-May-13 14:29 
QuestionProper Use of a Semaphore PinmemberRichard Andrew x649-May-13 14:14 
AnswerRe: Proper Use of a Semaphore PinmemberSledgeHammer019-May-13 17:05 
GeneralRe: Proper Use of a Semaphore PinmemberRichard Andrew x6410-May-13 6:10 
Questionhow do i display http fields Pinmembermais irreem9-May-13 3:35 
AnswerRe: how do i display http fields PinmvpOriginalGriff9-May-13 3:54 
QuestionHTML, RTF or WordML? PinmemberJassim Rahma8-May-13 23:47 
AnswerRe: HTML, RTF or WordML? PinmvpAbhinav S9-May-13 0:33 
AnswerRe: HTML, RTF or WordML? PinmvpDave Kreskowiak9-May-13 1:40 
QuestionLogin Form in Visual studio 2008 c# PinmemberAkash Bharatvala8-May-13 23:18 
AnswerRe: Login Form in Visual studio 2008 c# PinmvpAbhinav S9-May-13 0:23 
AnswerRe: Login Form in Visual studio 2008 c# PinmemberBikash Prakash Dash12-May-13 21:48 
QuestionPerformance issue using Multi threading in Net 3.5 PinmemberKIDYA8-May-13 20:35 
AnswerRe: Performance issue using Multi threading in Net 3.5 PinmvpAbhinav S8-May-13 21:10 
GeneralRe: Performance issue using Multi threading in Net 3.5 PinmemberKIDYA8-May-13 21:37 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.


Advertise | Privacy | Mobile
Web01 | 2.8.140926.1 | Last Updated 30 Sep 2014
Copyright © CodeProject, 1999-2014
All Rights Reserved. Terms of Service
Layout: fixed | fluid