Csharp/C Sharp/Network/Crypto Connection

Cryp Data Receiver

/*
C# Network Programming 
by Richard Blum
Publisher: Sybex 
ISBN: 0782141765
*/
using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Soap;
using System.Security;
using System.Security.Cryptography;
using System.Text;
public class CryptoDataRcvr
{
   private SerialEmployee RecvData(NetworkStream strm)
   {
      MemoryStream memstrm = new MemoryStream();
      byte[] Key = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
                    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16};
      byte[] IV = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
                   0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16};
      TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
      CryptoStream csw = new CryptoStream(memstrm, tdes.CreateDecryptor(Key, IV),
                         CryptoStreamMode.Write);
      byte[] data = new byte[2048];
      int recv = strm.Read(data, 0, 4);
      int size = BitConverter.ToInt32(data, 0);
      int offset = 0;
      while(size > 0)
      {
         recv = strm.Read(data, 0, size);
         csw.Write(data, offset, recv);
         offset += recv;
         size -= recv;
      }
      csw.FlushFinalBlock();
      IFormatter formatter = new SoapFormatter();
      memstrm.Position = 0;
      SerialEmployee emp = (SerialEmployee)formatter.Deserialize(memstrm);
      memstrm.Close();
      return emp;
   }      
   public CryptoDataRcvr()
   {
      TcpListener server = new TcpListener(9050);
      server.Start();
      Console.WriteLine("Waiting for a client...");
      TcpClient client = server.AcceptTcpClient();
      NetworkStream strm = client.GetStream();
      SerialEmployee emp1 = RecvData(strm);
      Console.WriteLine("emp1.EmployeeID = {0}", emp1.EmployeeID);
      Console.WriteLine("emp1.LastName = {0}", emp1.LastName);
      Console.WriteLine("emp1.FirstName = {0}", emp1.FirstName);
      Console.WriteLine("emp1.YearsService = {0}", emp1.YearsService);
      Console.WriteLine("emp1.Salary = {0}\n", emp1.Salary);
      SerialEmployee emp2 = RecvData(strm);
      Console.WriteLine("emp2.EmployeeID = {0}", emp2.EmployeeID);
      Console.WriteLine("emp2.LastName = {0}", emp2.LastName);
      Console.WriteLine("emp2.FirstName = {0}", emp2.FirstName);
      Console.WriteLine("emp2.YearsService = {0}", emp2.YearsService);
      Console.WriteLine("emp2.Salary = {0}", emp2.Salary);
      strm.Close();
      server.Stop();
   }
   public static void Main()
   {
      CryptoDataRcvr cdr = new CryptoDataRcvr();
   }
}
[Serializable]
public class SerialEmployee
{
   public int EmployeeID;
   public string LastName;
   public string FirstName;
   public int YearsService;
   public double Salary;
   public SerialEmployee()
   {
      EmployeeID = 0;
      LastName = null;
      FirstName = null;
      YearsService = 0;
      Salary = 0.0;
   }
}

Cryp Data Sender

/*
C# Network Programming 
by Richard Blum
Publisher: Sybex 
ISBN: 0782141765
*/
using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Soap;
using System.Security;
using System.Security.Cryptography;
using System.Text;
public class CryptoDataSender
{
   private void SendData(NetworkStream strm, SerialEmployee emp)
   {
      IFormatter formatter = new SoapFormatter();
      MemoryStream memstrm = new MemoryStream();
      byte[] Key = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16};
      byte[] IV = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16};
      TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
      CryptoStream csw = new CryptoStream(memstrm, tdes.CreateEncryptor(Key, IV), CryptoStreamMode.Write);
      formatter.Serialize(csw, emp);
      csw.FlushFinalBlock();
      byte[] data = memstrm.GetBuffer();
      int memsize = (int)memstrm.Length;
      byte[] size = BitConverter.GetBytes(memsize);
      strm.Write(size, 0, 4);
      strm.Write(data, 0, (int)memsize);
      strm.Flush();
      csw.Close();
      memstrm.Close();
   }
   public CryptoDataSender()
   {
      SerialEmployee emp1 = new SerialEmployee();
      SerialEmployee emp2 = new SerialEmployee();
      emp1.EmployeeID = 1;
      emp1.LastName = "Blum";
      emp1.FirstName = "Katie Jane";
      emp1.YearsService = 12;
      emp1.Salary = 35000.50;
      emp2.EmployeeID = 2;
      emp2.LastName = "Blum";
      emp2.FirstName = "Jessica";
      emp2.YearsService = 9;
      emp2.Salary = 23700.30;
      TcpClient client = new TcpClient("127.0.0.1", 9050);
      NetworkStream strm = client.GetStream();
      SendData(strm, emp1);
      SendData(strm, emp2);
      strm.Close();
      client.Close();
   }
   public static void Main()
   {
      CryptoDataSender cds = new CryptoDataSender();
   }
}

[Serializable]
public class SerialEmployee
{
   public int EmployeeID;
   public string LastName;
   public string FirstName;
   public int YearsService;
   public double Salary;
   public SerialEmployee()
   {
      EmployeeID = 0;
      LastName = null;
      FirstName = null;
      YearsService = 0;
      Salary = 0.0;
   }
}

CryptoStream demo

/*
C# Network Programming 
by Richard Blum
Publisher: Sybex 
ISBN: 0782141765
*/
using System;
using System.IO;
using System.Security;
using System.Security.Cryptography;
using System.Text;
public class CryptoTest
{
   public static void Main()
   {
      Console.Write("Enter phrase to encrypt: ");
      string phrase = Console.ReadLine();
      MemoryStream memstrm = new MemoryStream();
      byte[] Key = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
                    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16};
      byte[] IV = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
                   0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16};
      TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
      CryptoStream csw = new CryptoStream(memstrm,
                     tdes.CreateEncryptor(Key, IV), CryptoStreamMode.Write);
      csw.Write(Encoding.ASCII.GetBytes(phrase), 0, phrase.Length);
      csw.FlushFinalBlock();
      byte[] cryptdata = memstrm.GetBuffer();
      Console.WriteLine("Encrypted: {0}",
              Encoding.ASCII.GetString(cryptdata, 0, (int)memstrm.Length));
      memstrm.Position = 0;
      byte[] data = new byte[1024];
      CryptoStream csr = new CryptoStream(memstrm,
                     tdes.CreateDecryptor(Key, IV), CryptoStreamMode.Read);
      int recv = csr.Read(data, 0, data.Length);
      string newphrase = Encoding.ASCII.GetString(data, 0, recv);
      Console.WriteLine("Decrypted: {0}", newphrase);
      csr.Close();
      csw.Close();
      memstrm.Close();
   }
}