' Create a TCP/IP client socket.
' machineName is the host running the server application.
Dim client = New TcpClient(machineName, 443)
Console.WriteLine("Client connected.")

' Create an SSL stream that will close the client's stream.
Dim sslStream = New SslStream(
    client.GetStream(), False, 
    New RemoteCertificateValidationCallback(AddressOf ValidateServerCertificate), Nothing)

' The server name must match the name on the server certificate.
Try
    sslStream.AuthenticateAsClient(serverName)
Catch e As AuthenticationException
    Console.WriteLine("Exception: {0}", e.Message)

    If e.InnerException IsNot Nothing Then
        Console.WriteLine("Inner exception: {0}", e.InnerException.Message)
    End If

    Console.WriteLine("Authentication failed - closing the connection.")
    client.Close()
    Return
End Try

' Encode a test message into a byte array.
' Signal the end of the message using the "<EOF>".
Dim messsage As Byte() = Encoding.UTF8.GetBytes("Hello from the client.<EOF>")

' Send hello message to the server.
sslStream.Write(messsage)
sslStream.Flush()