using System;
using System.Collections;
using System.Net;
using System.Net.Sockets;
using System.Net.Security;
using System.Security.Authentication;
using System.Text;
using System.Security.Cryptography.X509Certificates;
using System.IO;

namespace Examples.System.Net
{
    public sealed class SslTcpServer 
    {
        static X509Certificate serverCertificate = null;
        // The certificate parameter specifies the name of the file 
        // containing the machine certificate.
        public static void RunServer(string certificate) 
        {
            serverCertificate = X509Certificate.CreateFromCertFile(certificate);
            // Create a TCP/IP (IPv4) socket and listen for incoming connections.
            TcpListener listener = new TcpListener(IPAddress.Any, 8080);    
            listener.Start();
            while (true) 
            {
                Console.WriteLine("Waiting for a client to connect...");
                // Application blocks while waiting for an incoming connection.
                // Type CNTL-C to terminate the server.
                TcpClient client = listener.AcceptTcpClient();
                ProcessClient(client);
            }
        }
        static void ProcessClient (TcpClient client)
        {
            // A client has connected. Create the 
            // SslStream using the client's network stream.
            SslStream sslStream = new SslStream(
                client.GetStream(), false);
            // Authenticate the server but don't require the client to authenticate.
            try 
            {
                sslStream.AuthenticateAsServer(serverCertificate, 
                    false, SslProtocols.Tls, true);
                // Display the properties and settings for the authenticated stream.
                DisplaySecurityLevel(sslStream);
                DisplaySecurityServices(sslStream);
                DisplayCertificateInformation(sslStream);
                DisplayStreamProperties(sslStream);

                // Set timeouts for the read and write to 5 seconds.
                sslStream.ReadTimeout = 5000;
                sslStream.WriteTimeout = 5000;
                // Read a message from the client.   
                Console.WriteLine("Waiting for client message...");
                string messageData = ReadMessage(sslStream);
                Console.WriteLine("Received: {0}", messageData);

                // Write a message to the client.
                byte[] message = Encoding.UTF8.GetBytes("Hello from the server.<EOF>");
                Console.WriteLine("Sending hello message.");
                sslStream.Write(message);
            }
            catch (AuthenticationException e)
            {
                Console.WriteLine("Exception: {0}", e.Message);
                if (e.InnerException != null)
                {
                    Console.WriteLine("Inner exception: {0}", e.InnerException.Message);
                }
                Console.WriteLine ("Authentication failed - closing the connection.");
                sslStream.Close();
                client.Close();
                return;
            }
            finally
            {
                // The client stream will be closed with the sslStream
                // because we specified this behavior when creating
                // the sslStream.
                sslStream.Close();
                client.Close();
            }
        }
        static string ReadMessage(SslStream sslStream)
        {
            // Read the  message sent by the client.
            // The client signals the end of the message using the
            // "<EOF>" marker.
            byte [] buffer = new byte[2048];
            StringBuilder messageData = new StringBuilder();
            int bytes = -1;
            do
            {
                // Read the client's test message.
                bytes = sslStream.Read(buffer, 0, buffer.Length);

                // Use Decoder class to convert from bytes to UTF8
                // in case a character spans two buffers.
                Decoder decoder = Encoding.UTF8.GetDecoder();
                char[] chars = new char[decoder.GetCharCount(buffer,0,bytes)];
                decoder.GetChars(buffer, 0, bytes, chars,0);
                messageData.Append (chars);
                // Check for EOF or an empty message.
                if (messageData.ToString().IndexOf("<EOF>") != -1)
                {
                    break;
                }
            } while (bytes !=0); 

            return messageData.ToString();
        }
         static void DisplaySecurityLevel(SslStream stream)
         {
            Console.WriteLine("Cipher: {0} strength {1}", stream.CipherAlgorithm, stream.CipherStrength);
            Console.WriteLine("Hash: {0} strength {1}", stream.HashAlgorithm, stream.HashStrength);
            Console.WriteLine("Key exchange: {0} strength {1}", stream.KeyExchangeAlgorithm, stream.KeyExchangeStrength);
            Console.WriteLine("Protocol: {0}", stream.SslProtocol);
         }
         static void DisplaySecurityServices(SslStream stream)
         {
            Console.WriteLine("Is authenticated: {0} as server? {1}", stream.IsAuthenticated, stream.IsServer);
            Console.WriteLine("IsSigned: {0}", stream.IsSigned);
            Console.WriteLine("Is Encrypted: {0}", stream.IsEncrypted);
         }
         static void DisplayStreamProperties(SslStream stream)
         {
            Console.WriteLine("Can read: {0}, write {1}", stream.CanRead, stream.CanWrite);
            Console.WriteLine("Can timeout: {0}", stream.CanTimeout);
         }
        static void DisplayCertificateInformation(SslStream stream)
        {
            Console.WriteLine("Certificate revocation list checked: {0}", stream.CheckCertRevocationStatus);

            X509Certificate localCertificate = stream.LocalCertificate;
            if (stream.LocalCertificate != null)
            {
                Console.WriteLine("Local cert was issued to {0} and is valid from {1} until {2}.",
                    localCertificate.Subject,
                    localCertificate.GetEffectiveDateString(),
                    localCertificate.GetExpirationDateString());
             } else
            {
                Console.WriteLine("Local certificate is null.");
            }
            // Display the properties of the client's certificate.
            X509Certificate remoteCertificate = stream.RemoteCertificate;
            if (stream.RemoteCertificate != null)
            {
            Console.WriteLine("Remote cert was issued to {0} and is valid from {1} until {2}.",
                remoteCertificate.Subject,
                remoteCertificate.GetEffectiveDateString(),
                remoteCertificate.GetExpirationDateString());
            } else
            {
                Console.WriteLine("Remote certificate is null.");
            }
        }
        private static void DisplayUsage()
        { 
            Console.WriteLine("To start the server specify:");
            Console.WriteLine("serverSync certificateFile.cer");
            Environment.Exit(1);
        }
        public static int Main(string[] args)
        {
            string certificate = null;
            if (args == null ||args.Length < 1 )
            {
                DisplayUsage();
            }
            certificate = args[0];
            SslTcpServer.RunServer (certificate);
            return 0;
        } 
    }
}

#using <System.dll>

using namespace System;
using namespace System::Collections;
using namespace System::Net;
using namespace System::Net::Sockets;
using namespace System::Net::Security;
using namespace System::Security::Authentication;
using namespace System::Text;
using namespace System::Security::Cryptography::X509Certificates;
using namespace System::IO;
public ref class SslTcpServer sealed
{
private:
   static X509Certificate^ serverCertificate = nullptr;

public:

   // The certificate parameter specifies the name of the file 
   // containing the machine certificate.
   static void RunServer( String^ certificate )
   {
      serverCertificate = X509Certificate::CreateFromCertFile( certificate );

      // Create a TCP/IP (IPv4) socket and listen for incoming connections.
      TcpListener^ listener = gcnew TcpListener( IPAddress::Any,8080 );
      listener->Start();

      while (true) 
      {
         Console::WriteLine( L"Waiting for a client to connect..." );

         // Application blocks while waiting for an incoming connection.
         // Type CNTL-C to terminate the server.
         TcpClient^ client = listener->AcceptTcpClient();
         ProcessClient( client );

      }
   }


   static void ProcessClient( TcpClient^ client )
   {

      // A client has connected. Create the 
      // SslStream using the client's network stream.
      SslStream^ sslStream = gcnew SslStream( client->GetStream(),false );

      // Authenticate the server but don't require the client to authenticate.
      try
      {
         sslStream->AuthenticateAsServer( serverCertificate, false, 
             SslProtocols::Tls, true );

         // Display the properties and settings for the authenticated stream.
         DisplaySecurityLevel( sslStream );
         DisplaySecurityServices( sslStream );
         DisplayCertificateInformation( sslStream );
         DisplayStreamProperties( sslStream );

         // Set timeouts for the read and write to 5 seconds.
         sslStream->ReadTimeout = 5000;
         sslStream->WriteTimeout = 5000;

         // Read a message from the client.   
         Console::WriteLine( L"Waiting for client message..." );
         String^ messageData = ReadMessage( sslStream );
         Console::WriteLine( L"Received: {0}", messageData );

         // Write a message to the client.
         array<Byte>^message = Encoding::UTF8->GetBytes( L"Hello from the server.<EOF>" );
         Console::WriteLine( L"Sending hello message." );
         sslStream->Write( message );
      }
      catch ( AuthenticationException^ e ) 
      {
         Console::WriteLine( L"Exception: {0}", e->Message );
         if ( e->InnerException != nullptr )
         {
            Console::WriteLine( L"Inner exception: {0}", e->InnerException->Message );
         }
         Console::WriteLine( L"Authentication failed - closing the connection." );
         sslStream->Close();
         client->Close();
         return;
      }
      finally
      {

         // The client stream will be closed with the sslStream
         // because we specified this behavior when creating
         // the sslStream.
         sslStream->Close();
         client->Close();
      }

   }


   static String^ ReadMessage( SslStream^ sslStream )
   {

      // Read the  message sent by the client.
      // The client signals the end of the message using the
      // "<EOF>" marker.
      array<Byte>^buffer = gcnew array<Byte>(2048);
      StringBuilder^ messageData = gcnew StringBuilder;
      int bytes = -1;
      do
      {

         // Read the client's test message.
         bytes = sslStream->Read( buffer, 0, buffer->Length );

         // Use Decoder class to convert from bytes to UTF8
         // in case a character spans two buffers.
         Decoder^ decoder = Encoding::UTF8->GetDecoder();
         array<Char>^chars = gcnew array<Char>(decoder->GetCharCount( buffer, 0, bytes ));
         decoder->GetChars( buffer, 0, bytes, chars, 0 );
         messageData->Append( chars );

         // Check for EOF or an empty message.
         if ( messageData->ToString()->IndexOf( L"<EOF>" ) != -1 )
         {
            break;
         }
      }
      while ( bytes != 0 );

      return messageData->ToString();
   }


   static void DisplaySecurityLevel( SslStream^ stream )
   {
      Console::WriteLine( L"Cipher: {0} strength {1}", stream->CipherAlgorithm, stream->CipherStrength );
      Console::WriteLine( L"Hash: {0} strength {1}", stream->HashAlgorithm, stream->HashStrength );
      Console::WriteLine( L"Key exchange: {0} strength {1}", stream->KeyExchangeAlgorithm, stream->KeyExchangeStrength );
      Console::WriteLine( L"Protocol: {0}", stream->SslProtocol );
   }


   static void DisplaySecurityServices( SslStream^ stream )
   {
      Console::WriteLine( L"Is authenticated: {0} as server? {1}", stream->IsAuthenticated, stream->IsServer );
      Console::WriteLine( L"IsSigned: {0}", stream->IsSigned );
      Console::WriteLine( L"Is Encrypted: {0}", stream->IsEncrypted );
   }


   static void DisplayStreamProperties( SslStream^ stream )
   {
      Console::WriteLine( L"Can read: {0}, write {1}", stream->CanRead, stream->CanWrite );
      Console::WriteLine( L"Can timeout: {0}", stream->CanTimeout );
   }


   static void DisplayCertificateInformation( SslStream^ stream )
   {
      Console::WriteLine( L"Certificate revocation list checked: {0}", stream->CheckCertRevocationStatus );
      X509Certificate^ localCertificate = stream->LocalCertificate;
      if ( stream->LocalCertificate != nullptr )
      {
         Console::WriteLine( L"Local cert was issued to {0} and is valid from {1} until {2}.", 
             localCertificate->Subject, 
             localCertificate->GetEffectiveDateString(), 
             localCertificate->GetExpirationDateString() );
      }
      else
      {
         Console::WriteLine( L"Local certificate is null." );
      }

      X509Certificate^ remoteCertificate = stream->RemoteCertificate;
      if ( stream->RemoteCertificate != nullptr )
      {
         Console::WriteLine( L"Remote cert was issued to {0} and is valid from {1} until {2}.", 
            remoteCertificate->Subject, 
            remoteCertificate->GetEffectiveDateString(), 
            remoteCertificate->GetExpirationDateString() );
      }
      else
      {
         Console::WriteLine( L"Remote certificate is null." );
      }
   }


private:

   static void DisplayUsage()
   {
      Console::WriteLine( L"To start the server specify:" );
      Console::WriteLine( L"serverSync certificateFile.cer" );
      Environment::Exit( 1 );
   }

public:
   int RunServerASync()
   {
      array<String^>^args = Environment::GetCommandLineArgs();
      String^ certificate = nullptr;
      if ( args == nullptr || args->Length < 2 )
      {
         DisplayUsage();
      }

      certificate = args[ 1 ];
      SslTcpServer::RunServer( certificate );
      return 0;
   }

};

int main(){
    SslTcpServer^ sts = gcnew SslTcpServer();
    sts->RunServerASync();
}

#using <mscorlib.dll>
#using <System.dll>
using namespace System;
using namespace System::Collections;
using namespace System::Net;
using namespace System::Net::Sockets;
using namespace System::Net::Security;
using namespace System::Security::Authentication;
using namespace System::Text;
using namespace System::Security::Cryptography::X509Certificates;
using namespace System::IO;

public __sealed __gc class SslTcpServer 
{
    static X509Certificate* serverCertificate = 0;
    // The certificate parameter specifies the name of the file 
    // containing the machine certificate.
public:
    static void RunServer(String* certificate) 
    {
        serverCertificate = X509Certificate::CreateFromCertFile(certificate);
        // Create a TCP/IP (IPv4) socket and listen for incoming connections.
        TcpListener* listener = new TcpListener(IPAddress::Any, 8080);    
        listener->Start();
        while (true) 
        {
            Console::WriteLine(S"Waiting for a client to connect...");
            // Application blocks while waiting for an incoming connection.
            // Type CNTL-C to terminate the server.
            TcpClient* client = listener->AcceptTcpClient();
            ProcessClient(client);
        }
    }
    static void ProcessClient (TcpClient* client)
    {
        // A client has connected. Create the 
        // SslStream using the client's network stream.
        SslStream* sslStream = new SslStream(
            client->GetStream(), false);
        // Authenticate the server but don't require the client to authenticate.
        try 
        {
            sslStream->ServerAuthenticate(serverCertificate, 
                false, SslProtocolType::Tls, true);
            // Display the properties and settings for the authenticated stream.
            DisplaySecurityLevel(sslStream);
            DisplaySecurityServices(sslStream);
            DisplayCertificateInformation(sslStream);
            DisplayStreamProperties(sslStream);

            // Set timeouts for the read and write to 5 seconds.
            sslStream->ReadTimeout = 5000;
            sslStream->WriteTimeout = 5000;
            // Read a message from the client.   
            Console::WriteLine(S"Waiting for client message...");
            String* messageData = ReadMessage(sslStream);
            Console::WriteLine(S"Received: {0}", messageData);

            // Write a message to the client.
            Byte message[] = Encoding::UTF8->GetBytes(S"Hello from the server.<EOF>");
            Console::WriteLine(S"Sending hello message.");
            sslStream->Write(message);
        }
        catch (AuthenticationException* e)
        {
            Console::WriteLine(S"Exception: {0}", e->Message);
            if (e->InnerException != 0)
            {
                Console::WriteLine(S"Inner exception: {0}", e->InnerException->Message);
            }
            Console::WriteLine (S"Authentication failed - closing the connection.");
            sslStream->Close();
            client->Close();
            return;
        }
        __finally
        {
            // The client stream will be closed with the sslStream
            // because we specified this behavior when creating
            // the sslStream.
            sslStream->Close();
            client->Close();
        }
    }
    static String* ReadMessage(SslStream* sslStream)
    {
        // Read the  message sent by the client.
        // The client signals the end of the message using the
        // "<EOF>" marker.
        Byte buffer[] = new Byte[2048];
        StringBuilder* messageData = new StringBuilder();
        int bytes = -1;
        do
        {
            // Read the client's test message.
            bytes = sslStream->Read(buffer, 0, buffer->Length);

            // Use Decoder class to convert from bytes to UTF8
            // in case a character spans two buffers.
            Decoder* decoder = Encoding::UTF8->GetDecoder();
            Char chars[] = new Char[decoder->GetCharCount(buffer,0,bytes)];
            decoder->GetChars(buffer, 0, bytes, chars,0);
            messageData->Append (chars);
            // Check for EOF or an empty message.
            if (messageData->ToString()->IndexOf(S"<EOF>") != -1)
            {
                break;
            }
        } while (bytes !=0); 

        return messageData->ToString();
    }
    static void DisplaySecurityLevel(SslStream* stream)
    {
        Console::WriteLine(S"Cipher: {0} strength {1}", __box(stream->CipherAlgorithm), __box(stream->CipherStrength));
        Console::WriteLine(S"Hash: {0} strength {1}", __box(stream->HashAlgorithm), __box(stream->HashStrength));
        Console::WriteLine(S"Key exchange: {0} strength {1}", __box(stream->KeyExchangeAlgorithm), __box(stream->KeyExchangeStrength));
        Console::WriteLine(S"Protocol: {0}", __box(stream->SslProtocol));
    }
    static void DisplaySecurityServices(SslStream* stream)
    {
        Console::WriteLine(S"Is authenticated: {0} as server? {1}", __box(stream->IsAuthenticated), __box(stream->IsServer));
        Console::WriteLine(S"IsSigned: {0}", __box(stream->IsSigned));
        Console::WriteLine(S"Is Encrypted: {0}", __box(stream->IsEncrypted));
    }
    static void DisplayStreamProperties(SslStream* stream)
    {
        Console::WriteLine(S"Can read: {0}, write {1}", __box(stream->CanRead), __box(stream->CanWrite));
        Console::WriteLine(S"Can timeout: {0}", __box(stream->CanTimeout));
    }
    static void DisplayCertificateInformation(SslStream* stream)
    {
        Console::WriteLine(S"Certificate revocation list checked: {0}", __box(stream->CheckCertRevocationStatus));

        X509Certificate* localCertificate = stream->LocalCertificate;
        if (stream->LocalCertificate != 0)
        {
            Console::WriteLine(S"Local cert was issued to {0} and is valid from {1} until {2}.",
                localCertificate->GetName(),
                localCertificate->GetEffectiveDateString(),
                localCertificate->GetExpirationDateString());
        } else
        {
            Console::WriteLine(S"Local certificate is null.");
        }
        // Display the properties of the client's certificate.
        X509Certificate* remoteCertificate = stream->RemoteCertificate;
        if (stream->RemoteCertificate != 0)
        {
            Console::WriteLine(S"Remote cert was issued to {0} and is valid from {1} until {2}.",
                remoteCertificate->GetName(),
                remoteCertificate->GetEffectiveDateString(),
                remoteCertificate->GetExpirationDateString());
        } else
        {
            Console::WriteLine(S"Remote certificate is null.");
        }
    }
private:
    static void DisplayUsage()
    { 
        Console::WriteLine(S"To start the server specify:");
        Console::WriteLine(S"serverSync certificateFile.cer");
        Environment::Exit(1);
    }
public:
    int RunServerASync()
    {
        String* args[] = Environment::GetCommandLineArgs();

        String* certificate = 0;
        if (args == 0 ||args->Length < 2 )
        {
            DisplayUsage();
        }
        certificate = args[1];
        SslTcpServer::RunServer (certificate);
        return 0;
    } 
};

int main(){
    SslTcpServer* sts = new SslTcpServer();
    sts->RunServerASync();
}

using System;
using System.Collections;
using System.Net;
using System.Net.Security;
using System.Net.Sockets;
using System.Security.Authentication;
using System.Text;
using System.Security.Cryptography.X509Certificates;
using System.IO;

namespace Examples.System.Net
{
    public class SslTcpClient 
    {   
        private static Hashtable certificateErrors = new Hashtable();

        // The following method is invoked by the RemoteCertificateValidationDelegate.
        public static bool ValidateServerCertificate(
              object sender,
              X509Certificate certificate,
              X509Chain chain,
              SslPolicyErrors sslPolicyErrors)
        {
           if (sslPolicyErrors == SslPolicyErrors.None)
                return true;

            Console.WriteLine("Certificate error: {0}", sslPolicyErrors);

            // Do not allow this client to communicate with unauthenticated servers.
            return false;
        }
        public static void RunClient(string machineName, string serverName)  
        {
            // Create a TCP/IP client socket.
            // machineName is the host running the server application.
            TcpClient client = new TcpClient(machineName,443);
            Console.WriteLine("Client connected.");
            // Create an SSL stream that will close the client's stream.
            SslStream sslStream = new SslStream(
                client.GetStream(), 
                false, 
                new RemoteCertificateValidationCallback (ValidateServerCertificate), 
                null
                );
            // The server name must match the name on the server certificate.
            try 
            {
                sslStream.AuthenticateAsClient(serverName);
            } 
            catch (AuthenticationException e)
            {
                Console.WriteLine("Exception: {0}", e.Message);
                if (e.InnerException != null)
                {
                    Console.WriteLine("Inner exception: {0}", e.InnerException.Message);
                }
                Console.WriteLine ("Authentication failed - closing the connection.");
                client.Close();
                return;
            }
            // Encode a test message into a byte array.
            // Signal the end of the message using the "<EOF>".
            byte[] messsage = Encoding.UTF8.GetBytes("Hello from the client.<EOF>");
            // Send hello message to the server. 
            sslStream.Write(messsage);
            sslStream.Flush();
            // Read message from the server.
            string serverMessage = ReadMessage(sslStream);
            Console.WriteLine("Server says: {0}", serverMessage);
            // Close the client connection.
            client.Close();
            Console.WriteLine("Client closed.");
        }
        static string ReadMessage(SslStream sslStream)
        {
            // Read the  message sent by the server.
            // The end of the message is signaled using the
            // "<EOF>" marker.
            byte [] buffer = new byte[2048];
            StringBuilder messageData = new StringBuilder();
            int bytes = -1;
            do
            {
                bytes = sslStream.Read(buffer, 0, buffer.Length);

                // Use Decoder class to convert from bytes to UTF8
                // in case a character spans two buffers.
                Decoder decoder = Encoding.UTF8.GetDecoder();
                char[] chars = new char[decoder.GetCharCount(buffer,0,bytes)];
                decoder.GetChars(buffer, 0, bytes, chars,0);
                messageData.Append (chars);
                // Check for EOF.
                if (messageData.ToString().IndexOf("<EOF>") != -1)
                {
                    break;
                }
            } while (bytes != 0); 

            return messageData.ToString();
        }
        private static void DisplayUsage()
        { 
            Console.WriteLine("To start the client specify:");
            Console.WriteLine("clientSync machineName [serverName]");
            Environment.Exit(1);
        }
        public static int Main(string[] args)
        {
            string serverCertificateName = null;
            string machineName = null;
            if (args == null ||args.Length <1 )
            {
                DisplayUsage();
            }
            // User can specify the machine name and server name.
            // Server name must match the name on the server's certificate. 
            machineName = args[0];
            if (args.Length <2 )
            {
                serverCertificateName = machineName;
            }
            else 
            {
                serverCertificateName = args[1];
            }
            SslTcpClient.RunClient (machineName, serverCertificateName);
            return 0;
        }
    }
}

#using <System.dll>
#using <System.Security.dll>

using namespace System;
using namespace System::Collections;
using namespace System::Globalization;
using namespace System::Net;
using namespace System::Net::Security;
using namespace System::Net::Sockets;
using namespace System::Security::Authentication;
using namespace System::Text;
using namespace System::Security::Cryptography::X509Certificates;
using namespace System::IO;

namespace NlsClientSync
{
    public ref class SslTcpClient
    {
    private:
        static Hashtable^ certificateErrors = gcnew Hashtable;
        // Load a table of errors that might cause 
        // the certificate authentication to fail.
        static void InitializeCertificateErrors()
        {
            certificateErrors->Add(0x800B0101,
                "The certification has expired.");
            certificateErrors->Add(0x800B0104,
                "A path length constraint "
                "in the certification chain has been violated.");
            certificateErrors->Add(0x800B0105,
                "A certificate contains an unknown extension "
                "that is marked critical.");
            certificateErrors->Add(0x800B0107,
                "A parent of a given certificate in fact "
                "did not issue that child certificate.");
            certificateErrors->Add(0x800B0108,
                "A certificate is missing or has an empty value "
                "for a necessary field.");
            certificateErrors->Add(0x800B0109,
                "The certificate root is not trusted.");
            certificateErrors->Add(0x800B010C,
                "The certificate has been revoked.");
            certificateErrors->Add(0x800B010F,
                "The name in the certificate does not not match "
                "the host name requested by the client.");
            certificateErrors->Add(0x800B0111,
                "The certificate was explicitly marked "
                "as untrusted by the user.");
            certificateErrors->Add(0x800B0112,
                "A certification chain processed correctly, "
                "but one of the CA certificates is not trusted.");
            certificateErrors->Add(0x800B0113,
                "The certificate has an invalid policy.");
            certificateErrors->Add(0x800B0114,
                "The certificate name is either not "
                "in the permitted list or is explicitly excluded.");
            certificateErrors->Add(0x80092012,
                "The revocation function was unable to check "
                "revocation for the certificate.");
            certificateErrors->Add(0x80090327,
                "An unknown error occurred while "
                "processing the certificate.");
            certificateErrors->Add(0x80096001,
                "A system-level error occurred "
                "while verifying trust.");
            certificateErrors->Add(0x80096002,
                "The certificate for the signer of the message "
                "is invalid or not found.");
            certificateErrors->Add(0x80096003,
                "One of the counter signatures was invalid.");
            certificateErrors->Add(0x80096004,
                "The signature of the certificate "
                "cannot be verified.");
            certificateErrors->Add(0x80096005,
                "The time stamp signature or certificate "
                "could not be verified or is malformed.");
            certificateErrors->Add(0x80096010,
                "The digital signature of the object "
                "was not verified.");
            certificateErrors->Add(0x80096019,
                "The basic constraint extension of a certificate "
                "has not been observed.");
        }

        static String^ CertificateErrorDescription(UInt32 problem)
        {
            // Initialize the error message dictionary 
            // if it is not yet available.
            if (certificateErrors->Count == 0)
            {
                InitializeCertificateErrors();
            }

            String^ description = safe_cast<String^>(
                certificateErrors[problem]);
            if (description == nullptr)
            {
                description = String::Format(
                    CultureInfo::CurrentCulture,
                    "Unknown certificate error - 0x{0:x8}",
                    problem);
            }

            return description;
        }

    public:
        // The following method is invoked 
        // by the CertificateValidationDelegate.
    static bool ValidateServerCertificate(
            Object^ sender,
            X509Certificate^ certificate,
            X509Chain^ chain,
            SslPolicyErrors sslPolicyErrors)
        {

            Console::WriteLine("Validating the server certificate.");
            if (sslPolicyErrors == SslPolicyErrors::None)
                return true;

            Console::WriteLine("Certificate error: {0}", sslPolicyErrors);

            // Do not allow this client to communicate with unauthenticated servers.
            return false;
        }

        static void RunClient(String^ machineName, String^ serverName)
        {

            // Create a TCP/IP client socket.
            // machineName is the host running the server application.
            TcpClient^ client = gcnew TcpClient(machineName, 8080);
            Console::WriteLine("Client connected.");

            // Create an SSL stream that will close 
            // the client's stream.
            SslStream^ sslStream = gcnew SslStream(
                client->GetStream(), false,
                gcnew RemoteCertificateValidationCallback(ValidateServerCertificate),
                nullptr);

            // The server name must match the name
            // on the server certificate.
            try
            {
                sslStream->AuthenticateAsClient(serverName);
            }
            catch (AuthenticationException^ ex) 
            {
                Console::WriteLine("Exception: {0}", ex->Message);
                if (ex->InnerException != nullptr)
                {
                    Console::WriteLine("Inner exception: {0}", 
                        ex->InnerException->Message);
                }

                Console::WriteLine("Authentication failed - "
                    "closing the connection.");
                sslStream->Close();
                client->Close();
                return;
            }
            // Encode a test message into a byte array.
            // Signal the end of the message using the "<EOF>".
            array<Byte>^ messsage = Encoding::UTF8->GetBytes(
                "Hello from the client.<EOF>");

            // Send hello message to the server.
            sslStream->Write(messsage);
            sslStream->Flush();
            // Read message from the server.
            String^ serverMessage = ReadMessage(sslStream);
            Console::WriteLine("Server says: {0}", serverMessage);

            // Close the client connection.
            sslStream->Close();
            client->Close();
            Console::WriteLine("Client closed.");
        }
    private:
        static String^ ReadMessage(SslStream^ sslStream)
        {

            // Read the  message sent by the server.
            // The end of the message is signaled using the
            // "<EOF>" marker.
            array<Byte>^ buffer = gcnew array<Byte>(2048);
            StringBuilder^ messageData = gcnew StringBuilder;
            // Use Decoder class to convert from bytes to UTF8
            // in case a character spans two buffers.
            Encoding^ u8 = Encoding::UTF8;
            Decoder^ decoder = u8->GetDecoder();

            int bytes = -1;
            do
            {
                bytes = sslStream->Read(buffer, 0, buffer->Length);

                array<__wchar_t>^ chars = gcnew array<__wchar_t>(
                    decoder->GetCharCount(buffer, 0, bytes));
                decoder->GetChars(buffer, 0, bytes, chars, 0);
                messageData->Append(chars);

                // Check for EOF.
                if (messageData->ToString()->IndexOf("<EOF>") != -1)
                {
                    break;
                }
            }
            while (bytes != 0);

            return messageData->ToString();
        }
    };
}

int main()
{
    array<String^>^ args = Environment::GetCommandLineArgs();
    String^ serverCertificateName = nullptr;
    String^ machineName = nullptr;
    if (args == nullptr || args->Length < 2)
    {
        Console::WriteLine("To start the client specify:");
        Console::WriteLine("clientSync machineName [serverName]");
        return 1;
    }

    // User can specify the machine name and server name.
    // Server name must match the name on 
    // the server's certificate.
    machineName = args[1];
    if (args->Length < 3)
    {
        serverCertificateName = machineName;
    }
    else
    {
        serverCertificateName = args[2];
    };

    NlsClientSync::SslTcpClient::RunClient(machineName,
        serverCertificateName);

    return 0;
}