/pop3/Pop3Client.cs

using System;

using System.Collections;

using System.IO;

using System.Net;

using System.Net.Sockets;

using System.Threading;

using System.Text;

using System.Text.RegularExpressions;

using System.Diagnostics;

using Org.Mentalis.Security.Ssl;



namespace Pop3

{

    public class Pop3Client

    {

        private Pop3Credential m_credential;



        public const int DEFAULT_POP3_PORT = 110;

        private const int MAX_BUFFER_READ_SIZE = 256;



        private long m_inboxPosition = 0;

        private long m_directPosition = -1;



        private SecureSocket m_socket = null;



        private Pop3Message m_pop3Message = null;



        public Pop3Credential UserDetails

        {

            set { m_credential = value; }

            get { return m_credential; }

        }



        public string MessageID

        {

            get { return m_pop3Message.MessageID; }

        }



        public string From

        {

            get { return m_pop3Message.From; }

        }



        public string To

        {

            get { return m_pop3Message.To; }

        }



        public string Subject

        {

            get { return m_pop3Message.Subject; }

        }



        public string Body

        {

            get { return m_pop3Message.Body; }

        }



        public IEnumerator MultipartEnumerator

        {

            get { return m_pop3Message.MultipartEnumerator; }

        }



        public bool IsMultipart

        {

            get { return m_pop3Message.IsMultipart; }

        }



        public Pop3Client(string user, string pass, string server)

        {

            m_credential = new Pop3Credential(user, pass, server);

        }



        public Pop3Client(string user, string pass, string server, int port)

        {

            m_credential = new Pop3Credential(user, pass, server, port);

        }



        public Pop3Client(string user, string pass, string server, int port, bool ssl_enabled)

        {

            m_credential = new Pop3Credential(user, pass, server, port, ssl_enabled);

        }



        private SecureSocket GetClientSocket()

        {

            SecureSocket s = null;



            try

            {

                IPHostEntry hostEntry = null;



                // Get host related information.

                hostEntry = Dns.GetHostEntry(m_credential.Server);



                // Loop through the AddressList to obtain the supported 

                // AddressFamily. This is to avoid an exception that 

                // occurs when the host IP Address is not compatible 

                // with the address family 

                // (typical in the IPv6 case).



                foreach (IPAddress address in hostEntry.AddressList)

                {

                    int port = DEFAULT_POP3_PORT;



                    if (m_credential.Port > 0)

                        port = m_credential.Port;



                    IPEndPoint ipe = new IPEndPoint(address, port);



                    //Socket tempSocket =

                    //    new Socket(ipe.AddressFamily, SocketType.Stream, ProtocolType.Tcp);



                    SecurityOptions secOpts;

                    if (m_credential.EnableSsl)

                        secOpts = new SecurityOptions(SecureProtocol.Ssl3);

                    else

                        secOpts = new SecurityOptions(SecureProtocol.None);



                    SecureSocket tempSocket =

                        new SecureSocket(ipe.AddressFamily, SocketType.Stream, ProtocolType.Tcp, secOpts);



                    tempSocket.Connect(ipe);



                    if (tempSocket.Connected)

                    {

                        // we have a connection.

                        // return this socket ...

                        s = tempSocket;

                        break;

                    }

                    else

                    {

                        continue;

                    }

                }

            }

            catch (Exception e)

            {

                throw new Pop3ConnectException(e.ToString());

            }



            // throw exception if can't connect ...

            if (s == null)

            {

                throw new Pop3ConnectException("Error : connecting to "

                    + m_credential.Server);

            }



            return s;

        }



        //send the data to server

        private void Send(String data)

        {

            if (m_socket == null)

            {

                throw new Pop3MessageException("Pop3 connection is closed");

            }



            try

            {

                // Convert the string data to byte data 

                // using Unicode encoding.



                byte[] byteData = Encoding.UTF8.GetBytes(data + "\r\n");



                // Begin sending the data to the remote device.

                m_socket.Send(byteData);

            }

            catch (Exception e)

            {

                throw new Pop3SendException(e.ToString());

            }

        }



        private string GetPop3String()

        {

            if (m_socket == null)

            {

                throw new

                    Pop3MessageException("Connection to POP3 server is closed");

            }



            byte[] buffer = new byte[MAX_BUFFER_READ_SIZE];

            string line = null;



            try

            {

                int byteCount =

                    m_socket.Receive(buffer, buffer.Length, 0);



                line =

                    Encoding.UTF8.GetString(buffer, 0, byteCount);

            }

            catch (Exception e)

            {

                throw new Pop3ReceiveException(e.ToString());

            }



            return line;

        }



        private void LoginToInbox()

        {

            string returned;



            // send username ...

            Send("user " + m_credential.User);



            // get response ...

            returned = GetPop3String();



            if (!returned.Substring(0, 3).Equals("+OK"))

            {

                throw new Pop3LoginException("login not excepted");

            }



            // send password ...

            Send("pass " + m_credential.Pass);



            // get response ...

            returned = GetPop3String();



            if (!returned.Substring(0, 3).Equals("+OK"))

            {

                throw new

                    Pop3LoginException("login/password not accepted");

            }

        }



        public long MessageCount

        {

            get

            {

                long count = 0;



                if (m_socket == null)

                {

                    throw new Pop3MessageException("Pop3 server not connected");

                }



                Send("stat");



                string returned = GetPop3String();



                // if values returned ...

                if (Regex.Match(returned,

                    @"^.*\+OK[ |	]+([0-9]+)[ |	]+.*$").Success)

                {

                    // get number of emails ...

                    count = long.Parse(Regex

                    .Replace(returned.Replace("\r\n", "")

                    , @"^.*\+OK[ |	]+([0-9]+)[ |	]+.*$", "$1"));

                }



                return (count);

            }

        }



        public void CloseConnection()

        {

            try

            {

                Send("quit");

            }

            catch { }



            if (m_socket != null)

            {

                m_socket.Close();

                m_socket = null;

            }

            m_pop3Message = null;

        }



        public bool DeleteEmail()

        {

            bool ret = false;



            Send("dele " + m_inboxPosition);



            string returned = GetPop3String();



            if (Regex.Match(returned,

                @"^.*\+OK.*$").Success)

            {

                ret = true;

            }



            return ret;

        }



        public bool NextEmail(long directPosition)

        {

            bool ret;



            if (directPosition >= 0)

            {

                m_directPosition = directPosition;

                ret = NextEmail();

            }

            else

            {

                throw new Pop3MessageException("Position less than zero");

            }



            return ret;

        }



        public bool NextEmail()

        {

            string returned;



            long pos;



            if (m_directPosition == -1)

            {

                if (m_inboxPosition == 0)

                {

                    pos = 1;

                }

                else

                {

                    pos = m_inboxPosition + 1;

                }

            }

            else

            {

                pos = m_directPosition + 1;

                m_directPosition = -1;

            }



            // send username ...

            Send("list " + pos.ToString());



            // get response ...

            returned = GetPop3String();



            // if email does not exist at this position

            // then return false ...



            if (returned.Substring(0, 4).Equals("-ERR"))

            {

                return false;

            }



            m_inboxPosition = pos;



            // strip out CRLF ...

            string[] noCr = returned.Split(new char[] { '\r' });



            // get size ...

            string[] elements = noCr[0].Split(new char[] { ' ' });



            long size = long.Parse(elements[2]);



            // ... else read email data

            m_pop3Message = new Pop3Message(m_inboxPosition, size, m_socket);



            return true;

        }



        public void OpenInbox()

        {

            // get a socket ...

            m_socket = GetClientSocket();



            // get initial header from POP3 server ...

            string header = GetPop3String();



            if (!header.Substring(0, 3).Equals("+OK"))

            {

                throw new Exception("Invalid initial POP3 response");

            }



            // send login details ...

            LoginToInbox();

        }

    }

}