LumiSoft MailServer

using System;
using System.IO;
using System.ComponentModel;
using System.Collections;
using System.Diagnostics;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Windows.Forms;
using System.Security.Cryptography.X509Certificates;

using LumiSoft.Net;
using LumiSoft.Net.AUTH;

namespace LumiSoft.Net.IMAP.Server
{
	#region Event delegates

	/// <summary>
	/// Represents the method that will handle the AuthUser event for SMTP_Server.
	/// </summary>
	/// <param name="sender">The source of the event. </param>
	/// <param name="e">A AuthUser_EventArgs that contains the event data.</param>
	public delegate void AuthUserEventHandler(object sender,AuthUser_EventArgs e);

	/// <summary>
	/// 
	/// </summary>
	public delegate void FolderEventHandler(object sender,Mailbox_EventArgs e);

	/// <summary>
	/// 
	/// </summary>
	public delegate void FoldersEventHandler(object sender,IMAP_Folders e);

	/// <summary>
	/// 
	/// </summary>
	public delegate void MessagesEventHandler(object sender,IMAP_eArgs_GetMessagesInfo e);

    /// <summary>
	/// 
	/// </summary>
	public delegate void MessagesItemsEventHandler(object sender,IMAP_eArgs_MessageItems e);

	/// <summary>
	/// 
	/// </summary>
	public delegate void MessageEventHandler(object sender,Message_EventArgs e);

    /*
	/// <summary>
	/// 
	/// </summary>
	public delegate void SearchEventHandler(object sender,IMAP_eArgs_Search e);*/

	/// <summary>
	/// 
	/// </summary>
	public delegate void SharedRootFoldersEventHandler(object sender,SharedRootFolders_EventArgs e);

	/// <summary>
	/// 
	/// </summary>
	public delegate void GetFolderACLEventHandler(object sender,IMAP_GETACL_eArgs e);

	/// <summary>
	/// 
	/// </summary>
	public delegate void DeleteFolderACLEventHandler(object sender,IMAP_DELETEACL_eArgs e);

	/// <summary>
	/// 
	/// </summary>
	public delegate void SetFolderACLEventHandler(object sender,IMAP_SETACL_eArgs e);

	/// <summary>
	/// 
	/// </summary>
	public delegate void GetUserACLEventHandler(object sender,IMAP_GetUserACL_eArgs e);


    /// <summary>
	/// 
	/// </summary>
	public delegate void GetUserQuotaHandler(object sender,IMAP_eArgs_GetQuota e);

	#endregion

	/// <summary>
	/// IMAP server componet.
	/// </summary>
	public class IMAP_Server : SocketServer
	{
        private int           m_MaxConnectionsPerIP = 0;
        private SaslAuthTypes m_SupportedAuth       = SaslAuthTypes.All;
        private string        m_GreetingText        = "";
		private int           m_MaxMessageSize      = 1000000;

		#region Events declarations

		/// <summary>
		/// Occurs when new computer connected to IMAP server.
		/// </summary>
		public event ValidateIPHandler ValidateIPAddress = null;

		/// <summary>
		/// Occurs when connected user tryes to authenticate.
		/// </summary>
		public event AuthUserEventHandler AuthUser = null;

		/// <summary>
		/// Occurs when server requests to subscribe folder.
		/// </summary>
		public event FolderEventHandler SubscribeFolder = null;

		/// <summary>
		/// Occurs when server requests to unsubscribe folder.
		/// </summary>
		public event FolderEventHandler UnSubscribeFolder = null;

		/// <summary>
		/// Occurs when server requests all available folders.
		/// </summary>
		public event FoldersEventHandler GetFolders = null;

		/// <summary>
		/// Occurs when server requests subscribed folders.
		/// </summary>
		public event FoldersEventHandler GetSubscribedFolders = null;

		/// <summary>
		/// Occurs when server requests to create folder.
		/// </summary>
		public event FolderEventHandler CreateFolder = null;

		/// <summary>
		/// Occurs when server requests to delete folder.
		/// </summary>
		public event FolderEventHandler DeleteFolder = null;

		/// <summary>
		/// Occurs when server requests to rename folder.
		/// </summary>
		public event FolderEventHandler RenameFolder = null;

		/// <summary>
		/// Occurs when server requests to folder messages info.
		/// </summary>
		public event MessagesEventHandler GetMessagesInfo = null;

		/// <summary>
		/// Occurs when server requests to delete message.
		/// </summary>
		public event MessageEventHandler DeleteMessage = null;

		/// <summary>
		/// Occurs when server requests to store message.
		/// </summary>
		public event MessageEventHandler StoreMessage = null;

        /*
		/// <summary>
		/// Occurs when server requests to search specified folder messages.
		/// </summary>
		public event SearchEventHandler Search = null;*/

		/// <summary>
		/// Occurs when server requests to store message flags.
		/// </summary>
		public event MessageEventHandler StoreMessageFlags = null;

		/// <summary>
		/// Occurs when server requests to copy message to new location.
		/// </summary>
		public event MessageEventHandler CopyMessage = null;

        /// <summary>
		/// Occurs when server requests to get message items.
		/// </summary>
		public event MessagesItemsEventHandler GetMessageItems = null;

		/// <summary>
		/// Occurs when IMAP session has finished and session log is available.
		/// </summary>
		public event LogEventHandler SessionLog = null;

		/// <summary>
		/// Occurs when IMAP server requests shared root folders info.
		/// </summary>
		public event SharedRootFoldersEventHandler GetSharedRootFolders = null;

		/// <summary>
		/// Occurs when IMAP server requests folder ACL.
		/// </summary>
		public event GetFolderACLEventHandler GetFolderACL = null;

		/// <summary>
		/// Occurs when IMAP server requests to delete folder ACL.
		/// </summary>
		public event DeleteFolderACLEventHandler DeleteFolderACL = null;

		/// <summary>
		/// Occurs when IMAP server requests to set folder ACL.
		/// </summary>
		public event SetFolderACLEventHandler SetFolderACL = null;

		/// <summary>
		/// Occurs when IMAP server requests to get user ACL for specified folder.
		/// </summary>
		public event GetUserACLEventHandler GetUserACL = null;

        /// <summary>
		/// Occurs when IMAP server requests to get user quota.
		/// </summary>
		public event GetUserQuotaHandler GetUserQuota = null;
		
		#endregion

		
		/// <summary>
		/// Defalut constructor.
		/// </summary>
		public IMAP_Server() : base()
		{
			this.BindInfo = new BindInfo[]{new BindInfo(IPAddress.Any,143,false,null)};
		}


		#region override InitNewSession

		/// <summary>
		/// Initialize and start new session here. Session isn't added to session list automatically, 
		/// session must add itself to server session list by calling AddSession().
		/// </summary>
		/// <param name="socket">Connected client socket.</param>
        /// <param name="bindInfo">BindInfo what accepted socket.</param>
		protected override void InitNewSession(Socket socket,BindInfo bindInfo)
		{
            // Check maximum conncurent connections from 1 IP.
            if(m_MaxConnectionsPerIP > 0){
                lock(this.Sessions){
                    int nSessions = 0;
                    foreach(SocketServerSession s in this.Sessions){
                        IPEndPoint ipEndpoint = s.RemoteEndPoint;
                        if(ipEndpoint != null){
                            if(ipEndpoint.Address.Equals(((IPEndPoint)socket.RemoteEndPoint).Address)){
                                nSessions++;
                            }
                        }

                        // Maimum allowed exceeded
                        if(nSessions >= m_MaxConnectionsPerIP){
                            socket.Send(System.Text.Encoding.ASCII.GetBytes("* NO Maximum connections from your IP address is exceeded, try again later !\r\n"));
                            socket.Shutdown(SocketShutdown.Both);
                            socket.Close();
                            return;
                        }
                    }
                }
            }

            string   sessionID = Guid.NewGuid().ToString();
            SocketEx socketEx  = new SocketEx(socket);
            if(LogCommands){
                socketEx.Logger = new SocketLogger(socket,this.SessionLog);
				socketEx.Logger.SessionID = sessionID;
            }
			IMAP_Session session = new IMAP_Session(sessionID,socketEx,bindInfo,this);
		}

		#endregion


		#region Properties Implementaion
		
        /// <summary>
		/// Gets or sets server supported authentication types.
		/// </summary>
		public SaslAuthTypes SupportedAuthentications
		{
			get{ return m_SupportedAuth; }

			set{ m_SupportedAuth = value; }
		}

	    /// <summary>
		/// Gets or sets server greeting text.
		/// </summary>
		public string GreetingText
		{
			get{ return m_GreetingText; }

			set{ m_GreetingText = value; }
		}

        /// <summary>
		/// Gets or sets maximum allowed conncurent connections from 1 IP address. Value 0 means unlimited connections.
		/// </summary>
		public int MaxConnectionsPerIP
		{
			get{ return m_MaxConnectionsPerIP; }

			set{ m_MaxConnectionsPerIP = value; }
		}
	
		/// <summary>
		/// Maximum message size.
		/// </summary>
		public int MaxMessageSize 
		{
			get{ return m_MaxMessageSize; }

			set{ m_MaxMessageSize = value; }
		}

        /// <summary>
		/// Gets active sessions.
		/// </summary>
		public new IMAP_Session[] Sessions
		{
			get{
                SocketServerSession[] sessions     = base.Sessions;
                IMAP_Session[]        imapSessions = new IMAP_Session[sessions.Length];
                sessions.CopyTo(imapSessions,0);

                return imapSessions; 
            }
		}
		
		#endregion

		#region Events Implementation

		#region function OnValidate_IpAddress
		
		/// <summary>
		/// Raises event ValidateIP event.
		/// </summary>
		/// <param name="localEndPoint">Server IP.</param>
		/// <param name="remoteEndPoint">Connected client IP.</param>
		/// <returns>Returns true if connection allowed.</returns>
		internal bool OnValidate_IpAddress(IPEndPoint localEndPoint,IPEndPoint remoteEndPoint) 
		{			
			ValidateIP_EventArgs oArg = new ValidateIP_EventArgs(localEndPoint,remoteEndPoint);
			if(this.ValidateIPAddress != null){
				this.ValidateIPAddress(this, oArg);
			}

			return oArg.Validated;						
		}

		#endregion

		#region function OnAuthUser

		/// <summary>
		/// Raises event AuthUser.
		/// </summary>
		/// <param name="session">Reference to current IMAP session.</param>
		/// <param name="userName">User name.</param>
		/// <param name="passwordData">Password compare data,it depends of authentication type.</param>
		/// <param name="data">For md5 eg. md5 calculation hash.It depends of authentication type.</param>
		/// <param name="authType">Authentication type.</param>
		/// <returns>Returns true if user is authenticated ok.</returns>
		internal AuthUser_EventArgs OnAuthUser(IMAP_Session session,string userName,string passwordData,string data,AuthType authType)
		{
			AuthUser_EventArgs oArgs = new AuthUser_EventArgs(session,userName,passwordData,data,authType);
			if(this.AuthUser != null){
				this.AuthUser(this,oArgs);
			}

			return oArgs;
		}

		#endregion


		#region function OnSubscribeMailbox

		/// <summary>
		/// Raises event 'SubscribeMailbox'.
		/// </summary>
		/// <param name="session">Reference to IMAP session.</param>
		/// <param name="mailbox">Mailbox which to subscribe.</param>
		/// <returns></returns>
		internal string OnSubscribeMailbox(IMAP_Session session,string mailbox)
		{
			if(this.SubscribeFolder != null){
				Mailbox_EventArgs eArgs = new Mailbox_EventArgs(mailbox);
				this.SubscribeFolder(session,eArgs);

				return eArgs.ErrorText;
			}

			return null;
		}

		#endregion

		#region function OnUnSubscribeMailbox

		/// <summary>
		/// Raises event 'UnSubscribeMailbox'.
		/// </summary>
		/// <param name="session">Reference to IMAP session.</param>
		/// <param name="mailbox">Mailbox which to unsubscribe.</param>
		/// <returns></returns>
		internal string OnUnSubscribeMailbox(IMAP_Session session,string mailbox)
		{
			if(this.UnSubscribeFolder != null){
				Mailbox_EventArgs eArgs = new Mailbox_EventArgs(mailbox);
				this.UnSubscribeFolder(session,eArgs);

				return eArgs.ErrorText;
			}

			return null;
		}

		#endregion

		#region function OnGetSubscribedMailboxes

		/// <summary>
		/// Raises event 'GetSubscribedMailboxes'.
		/// </summary>
		/// <param name="session">Reference to IMAP session.</param>
		/// <param name="referenceName">Mailbox reference.</param>
		/// <param name="mailBox">Mailbox search pattern or mailbox.</param>
		/// <returns></returns>
		internal IMAP_Folders OnGetSubscribedMailboxes(IMAP_Session session,string referenceName,string mailBox)
		{
			IMAP_Folders retVal = new IMAP_Folders(session,referenceName,mailBox);
			if(this.GetSubscribedFolders != null){
				this.GetSubscribedFolders(session,retVal);
			}

			return retVal;
		}

		#endregion

		#region function OnGetMailboxes

		/// <summary>
		/// Raises event 'GetMailboxes'.
		/// </summary>
		/// <param name="session">Reference to IMAP session.</param>
		/// <param name="referenceName">Mailbox reference.</param>
		/// <param name="mailBox">Mailbox search pattern or mailbox.</param>
		/// <returns></returns>
		internal IMAP_Folders OnGetMailboxes(IMAP_Session session,string referenceName,string mailBox)
		{
			IMAP_Folders retVal = new IMAP_Folders(session,referenceName,mailBox);
			if(this.GetFolders != null){
				this.GetFolders(session,retVal);
			}

			return retVal;
		}

		#endregion

		#region function OnCreateMailbox

		/// <summary>
		/// Raises event 'CreateMailbox'.
		/// </summary>
		/// <param name="session">Reference to IMAP session.</param>
		/// <param name="mailbox">Mailbox to create.</param>
		/// <returns></returns>
		internal string OnCreateMailbox(IMAP_Session session,string mailbox)
		{
			if(this.CreateFolder != null){
				Mailbox_EventArgs eArgs = new Mailbox_EventArgs(mailbox);
				this.CreateFolder(session,eArgs);

				return eArgs.ErrorText;
			}

			return null;
		}

		#endregion

		#region function OnDeleteMailbox

		/// <summary>
		/// Raises event 'DeleteMailbox'.
		/// </summary>
		/// <param name="session">Reference to IMAP session.</param>
		/// <param name="mailbox">Mailbox which to delete.</param>
		/// <returns></returns>
		internal string OnDeleteMailbox(IMAP_Session session,string mailbox)
		{
			if(this.DeleteFolder != null){
				Mailbox_EventArgs eArgs = new Mailbox_EventArgs(mailbox);
				this.DeleteFolder(session,eArgs);

				return eArgs.ErrorText;
			}

			return null;
		}

		#endregion

		#region function OnRenameMailbox

		/// <summary>
		/// Raises event 'RenameMailbox'.
		/// </summary>
		/// <param name="session">Reference to IMAP session.</param>
		/// <param name="mailbox">Mailbox which to rename.</param>
		/// <param name="newMailboxName">New mailbox name.</param>
		/// <returns></returns>
		internal string OnRenameMailbox(IMAP_Session session,string mailbox,string newMailboxName)
		{
			if(this.RenameFolder != null){
				Mailbox_EventArgs eArgs = new Mailbox_EventArgs(mailbox,newMailboxName);
				this.RenameFolder(session,eArgs);

				return eArgs.ErrorText;
			}

			return null;
		}

		#endregion

		#region method OnGetMessagesInfo

		/// <summary>
		/// Raises event 'GetMessagesInfo'.
		/// </summary>
		/// <param name="session">Reference to IMAP session.</param>
		/// <param name="folder">Folder which messages info to get.</param>
		/// <returns></returns>
		internal IMAP_eArgs_GetMessagesInfo OnGetMessagesInfo(IMAP_Session session,IMAP_SelectedFolder folder)
		{
			IMAP_eArgs_GetMessagesInfo eArgs = new IMAP_eArgs_GetMessagesInfo(session,folder);
			if(this.GetMessagesInfo != null){
				this.GetMessagesInfo(session,eArgs);
			}

			return eArgs;
		}

		#endregion

        #region method OnGetMessageItems

        /// <summary>
        /// Raises event GetMessageItems.
        /// </summary>
        /// <param name="session">Reference to IMAP session.</param>
        /// <param name="messageInfo">Message info what message items to get.</param>
        /// <param name="messageItems">Specifies message items what must be filled.</param>
        /// <returns></returns>
        internal protected IMAP_eArgs_MessageItems OnGetMessageItems(IMAP_Session session,IMAP_Message messageInfo,IMAP_MessageItems_enum messageItems)
        {
            IMAP_eArgs_MessageItems eArgs = new IMAP_eArgs_MessageItems(session,messageInfo,messageItems);
            if(this.GetMessageItems != null){
				this.GetMessageItems(session,eArgs);
			}
            return eArgs;
        }

        #endregion

		#region function OnDeleteMessage

		/// <summary>
		/// Raises event 'DeleteMessage'.
		/// </summary>
		/// <param name="session">Reference to IMAP session.</param>
		/// <param name="message">Message which to delete.</param>
		/// <returns></returns>
		internal string OnDeleteMessage(IMAP_Session session,IMAP_Message message)
		{
			Message_EventArgs eArgs = new Message_EventArgs(Core.Decode_IMAP_UTF7_String(session.SelectedMailbox),message);
			if(this.DeleteMessage != null){
				this.DeleteMessage(session,eArgs);
			}

			return eArgs.ErrorText;
		}

		#endregion

		#region function OnCopyMessage

		/// <summary>
		/// Raises event 'CopyMessage'.
		/// </summary>
		/// <param name="session">Reference to IMAP session.</param>
		/// <param name="msg">Message which to copy.</param>
		/// <param name="location">New message location.</param>
		/// <returns></returns>
		internal string OnCopyMessage(IMAP_Session session,IMAP_Message msg,string location)
		{
			Message_EventArgs eArgs = new Message_EventArgs(Core.Decode_IMAP_UTF7_String(session.SelectedMailbox),msg,location);
			if(this.CopyMessage != null){
				this.CopyMessage(session,eArgs);
			}

			return eArgs.ErrorText;
		}

		#endregion

		#region function OnStoreMessage

		/// <summary>
		/// Raises event 'StoreMessage'.
		/// </summary>
		/// <param name="session">Reference to IMAP session.</param>
		/// <param name="folder">Folder where to store.</param>
		/// <param name="msg">Message which to store.</param>
		/// <param name="messageData">Message data which to store.</param>
		/// <returns></returns>
		internal string OnStoreMessage(IMAP_Session session,string folder,IMAP_Message msg,byte[] messageData)
		{
			Message_EventArgs eArgs = new Message_EventArgs(folder,msg);
			eArgs.MessageData = messageData;
			if(this.StoreMessage != null){
				this.StoreMessage(session,eArgs);
			}

			return eArgs.ErrorText;
		}

		#endregion

		#region method OnSearch
        /*
		/// <summary>
		/// Raises event 'Search'.
		/// </summary>
		/// <param name="session">IMAP session what calls this search.</param>
		/// <param name="folder">Folder what messages to search.</param>
		/// <param name="matcher">Matcher what must be used to check if message matches searching criterial.</param>
		/// <returns></returns>
		internal IMAP_eArgs_Search OnSearch(IMAP_Session session,string folder,IMAP_SearchMatcher matcher)
		{
			IMAP_eArgs_Search eArgs = new IMAP_eArgs_Search(session,folder,matcher);
			if(this.Search != null){
				this.Search(session,eArgs);
			}

			return eArgs;
		}*/

		#endregion

		#region function OnStoreMessageFlags

		/// <summary>
		/// Raises event 'StoreMessageFlags'.
		/// </summary>
		/// <param name="session">Reference to IMAP session.</param>
		/// <param name="msg">Message which flags to store.</param>
		/// <returns></returns>
		internal string OnStoreMessageFlags(IMAP_Session session,IMAP_Message msg)
		{
			Message_EventArgs eArgs = new Message_EventArgs(Core.Decode_IMAP_UTF7_String(session.SelectedMailbox),msg);
			if(this.StoreMessageFlags != null){
				this.StoreMessageFlags(session,eArgs);
			}

			return eArgs.ErrorText;
		}

		#endregion

		#region method OnGetSharedRootFolders

		internal SharedRootFolders_EventArgs OnGetSharedRootFolders(IMAP_Session session)
		{
			SharedRootFolders_EventArgs eArgs = new SharedRootFolders_EventArgs(session);
			if(this.GetSharedRootFolders != null){
				this.GetSharedRootFolders(session,eArgs);
			}

			return eArgs;
		}

		#endregion


		#region method OnGetFolderACL

		internal IMAP_GETACL_eArgs OnGetFolderACL(IMAP_Session session,string folderName)
		{
			IMAP_GETACL_eArgs eArgs = new IMAP_GETACL_eArgs(session,folderName);
			if(this.GetFolderACL != null){
				this.GetFolderACL(session,eArgs);
			}

			return eArgs;
		}

		#endregion

		#region method OnSetFolderACL

		internal IMAP_SETACL_eArgs OnSetFolderACL(IMAP_Session session,string folderName,string userName,IMAP_Flags_SetType flagsSetType,IMAP_ACL_Flags aclFlags)
		{
			IMAP_SETACL_eArgs eArgs = new IMAP_SETACL_eArgs(session,folderName,userName,flagsSetType,aclFlags);
			if(this.SetFolderACL != null){
				this.SetFolderACL(session,eArgs);
			}

			return eArgs;
		}

		#endregion

		#region method OnDeleteFolderACL

		internal IMAP_DELETEACL_eArgs OnDeleteFolderACL(IMAP_Session session,string folderName,string userName)
		{
			IMAP_DELETEACL_eArgs eArgs = new IMAP_DELETEACL_eArgs(session,folderName,userName);
			if(this.DeleteFolderACL != null){
				this.DeleteFolderACL(session,eArgs);
			}

			return eArgs;
		}

		#endregion

		#region method OnGetUserACL

		internal IMAP_GetUserACL_eArgs OnGetUserACL(IMAP_Session session,string folderName,string userName)
		{
			IMAP_GetUserACL_eArgs eArgs = new IMAP_GetUserACL_eArgs(session,folderName,userName);
			if(this.GetUserACL != null){
				this.GetUserACL(session,eArgs);
			}

			return eArgs;
		}

		#endregion


        #region method OnGetUserQuota

		internal IMAP_eArgs_GetQuota OnGetUserQuota(IMAP_Session session)
		{
			IMAP_eArgs_GetQuota eArgs = new IMAP_eArgs_GetQuota(session);
			if(this.GetUserQuota != null){
				this.GetUserQuota(session,eArgs);
			}

			return eArgs;
		}

		#endregion

		#endregion

	}
}