package de.tudarmstadt.informatik.hostage.protocol;

import java.nio.ByteBuffer;
import java.security.SecureRandom;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.List;
import java.util.TimeZone;

import de.tudarmstadt.informatik.hostage.HoneyService;
import de.tudarmstadt.informatik.hostage.R;
import de.tudarmstadt.informatik.hostage.commons.HelperUtils;
import de.tudarmstadt.informatik.hostage.wrapper.Packet;

/**
 * SMB protocol.
 * It can handle the following requests: Negotiate Protocol Request, Session Setup AndX Request, 
 * Tree Connect AndX Request, NT Create AndX Request, Bind, NetShareEnumAll, Close Request, 
 * Tree Disconnect Request, Echo Request, Trans2 Request.
 * @author Wulf Pfeiffer
 */
public class SMB implements Protocol {
	/**
	 * Represents the states of the protocol
	 */
	private static enum STATE {
		NONE, CONNECTED, AUTHENTICATED, LISTING, DISCONNECTED, CLOSED
	}
	
	/**
	 * Denotes in which state the protocol is right now
	 */
	private STATE state = STATE.NONE;

	private byte[] lastMessage;
	
	@Override
	public int getDefaultPort() {
		return 445;
	}

	@Override
	public TALK_FIRST whoTalksFirst() {
		return TALK_FIRST.CLIENT;
	}
	
	@Override
	public List<Packet> processMessage(Packet requestPacket) {
		if(requestPacket != null)
			lastMessage = requestPacket.getMessage();
		parseMessageHeader(lastMessage);
		byte smbCommand = getSmbCommand();
		List<Packet> responsePackets = new ArrayList<Packet>();

		switch (state) {
		case NONE:
			if (smbCommand == SMB_COM_NEGOTIATE) {
				state = STATE.CONNECTED;
				responsePackets.add(getNego());
			} else {
				state = STATE.DISCONNECTED;
				responsePackets.add(getTreeDisc());
			}
			break;
		case CONNECTED:
			if (smbCommand == SMB_COM_SESSION_SETUP_ANDX) {
				responsePackets.add(getSessSetup());
			} else if (smbCommand == SMB_COM_TREE_CONNECT_ANDX) {
				state = STATE.AUTHENTICATED;
				responsePackets.add(getTreeCon());
			} else {
				state = STATE.DISCONNECTED;
				responsePackets.add(getTreeDisc());
			}
			break;
		case AUTHENTICATED:
			if (smbCommand == SMB_COM_NT_CREATE_ANDX) {
				state = STATE.LISTING;
				responsePackets.add(getNTCreate());
			} else if (smbCommand == SMB_COM_ECHO) {
				responsePackets.add(getEcho());
			} else if (smbCommand == SMB_COM_TRANSACTION2) {
				responsePackets.add(getTrans2());
			} else if (smbCommand == SMB_COM_CLOSE) {
				responsePackets.add(getClose());
			} else if (smbCommand == SMB_COM_TREE_DISCONNECT) {
				state = STATE.CLOSED;
				responsePackets.add(getTreeDisc());
			} else {
				state = STATE.DISCONNECTED;
				responsePackets.add(getTreeDisc());
			}
			break;
		case LISTING:
			if (smbCommand == SMB_COM_TRANSACTION) {
				responsePackets.add(getTrans());
			} else if (smbCommand == SMB_COM_CLOSE) {
				responsePackets.add(getClose());
			} else if (smbCommand == SMB_COM_TREE_DISCONNECT) {
				state = STATE.CLOSED;
				responsePackets.add(getTreeDisc());
			} else if (smbCommand == SMB_COM_NEGOTIATE) {
				state = STATE.CONNECTED;
				responsePackets.add(getNego());
			} else {
				state = STATE.DISCONNECTED;
				responsePackets.add(getTreeDisc());
			}
			break;
		case DISCONNECTED:
			state = STATE.CLOSED;
			responsePackets.add(getTreeDisc());
			break;
		default:
			state = STATE.CLOSED;
			responsePackets.add(getTreeDisc());
		}
		return responsePackets;
	}

	@Override
	public boolean isClosed() {
		return (state == STATE.CLOSED);
	}

	@Override
	public boolean isSecure() {
		return false;
	}

	@Override
	public Class<byte[]> getType() {
		return byte[].class;
	}

	@Override
	public String toString() {
		return "SMB";
	}

	/**
	 * Converts the current system time into a byte[] with windows specific time
	 * @return current system time in windows format as byte[]
	 */
	private static byte[] getTimeInBytes() {
		long time = System.currentTimeMillis();
		Calendar calend = Calendar.getInstance();
		calend.setTimeZone(TimeZone.getTimeZone("UTC"));
		calend.set(1601, 0, 01, 00, 00, 00);
		time -= calend.getTimeInMillis();
		time *= 10000;

		byte[] timeInWindowsBytes = new byte[8];
		byte[] timeInBytes = ByteBuffer.allocate(8).putLong(time).array();

		for (int i = 0, j = 7; i < 8 && j > -1; i++, j--) {
			timeInWindowsBytes[i] = (byte) (timeInBytes[j] & 0xff);
		}

		return timeInWindowsBytes;
	}
	
	/**
	 * Converts the current timezone into a byte[] with windows specific format
	 * @return current timezone in windows format as byte[]
	 */
	private static byte[] getTimeZoneInBytes() {
		Integer offset = new GregorianCalendar().getTimeZone().getRawOffset() / 1000 / 60; // get current timezone offset in minutes
		char[] offsetChars = Integer.toBinaryString(offset).toCharArray();
		boolean invert = false;
		for(int i = offsetChars.length-1; i > -1; i--) {
			if(!invert && offsetChars[i] == '1') {
				invert = true;
			} else if(invert) {
				offsetChars[i] = (offsetChars[i] == '0')? '1' : '0';
			}
		}
		char[] extendedChars = new char[31];
		for(int i = 0; i < extendedChars.length-offsetChars.length; i++) {
			extendedChars[i] = '1';
		}
		for(int i = 0; i < offsetChars.length; i++) {
			extendedChars[i+extendedChars.length-offsetChars.length] = offsetChars[i];
		}
		int timezone = (int) Integer.parseInt(new String(extendedChars), 2);
		byte[] timezoneBytes = new byte[2];
		timezoneBytes[1] = (byte) (timezone >> 8);
		timezoneBytes[0] = (byte) (timezone);
		return timezoneBytes;
	}

	//version stuff
	private static String[][] possibleSmbVersions = {
		{"Windows 7 Professional 7600","Windows 7 Professional 6.1"},
		{"Windows 8 Enterprise 9200", "Windows 8 Enterprise 9200"},
		{"Windows Server 2008 R2 Enterprise 7600","Windows Server 2008 R2 Enterprise 6.1"},
		{"Windows Server 2012 Standard 6.2", "Windows Server 2012 Standard 6.2"},
		{"Unix", "Samba"}
	};
	private static String[] initServerVersion() {
		String sharedPreferencePath = HoneyService.getContext().getString(R.string.shared_preference_path);
		String profile = HoneyService.getContext().getSharedPreferences(sharedPreferencePath, HoneyService.MODE_PRIVATE).getString("profile", "");
		System.out.println(profile);
		if(profile.equals("Windows 7")) {
			return possibleSmbVersions[0];
		} else if(profile.equals("Windows 8")) {
			return possibleSmbVersions[1];
		} else if(profile.equals("Windows Server 2008")) {
			return possibleSmbVersions[2];
		} else if(profile.equals("Windows Server 2012")) {
			return possibleSmbVersions[3];
		} else if(profile.equals("Linux")) {
			return possibleSmbVersions[4];
		} else {
			return possibleSmbVersions[new SecureRandom().nextInt(possibleSmbVersions.length)];
		}
	}
	
	private static byte[] serverName		= HelperUtils.fillWithZero(HelperUtils.getRandomString(16, true).getBytes());
	private static String[] serverVersion	= initServerVersion();
		
	private byte[] message						= null; 
	private static final byte[] serverGUID		= HelperUtils.randomBytes(16);
	private boolean authenticateNext			= false;
	//components of a SMB packet
	private byte[] serverComp 		= new byte[4];
	private byte[] smbCommand		= new byte[1];
	private byte[] ntStat 			= new byte[4];
	private byte[] smbFlags			= new byte[1];	
	private byte[] smbFlags2		= new byte[2];
	private byte[] processIDHigh	= new byte[2];
	private byte[] signature	 	= new byte[8];
	private byte[] reserved			= new byte[2];
	private byte[] treeID			= new byte[2];
	private byte[] processID		= new byte[2];
	private byte[] userID			= new byte[2];
	private byte[] multiplexID		= new byte[2];

	/**
	 * Breaks a message from the client down into its components
	 * @param message that is analyzed
	 */
	private void parseMessageHeader(byte[] message) {
		this.message 	= message;
		serverComp 		= new byte[]{message[4], message[5], message[6], message[7]};
		smbCommand		= new byte[]{message[8]};
		ntStat 			= new byte[]{message[9], message[10], message[11], message[12]};
		smbFlags		= new byte[]{(byte) (message[13] | 0x80)};		// | 0x80 for mark response bit
		smbFlags2		= new byte[]{message[14], message[15]};
		processIDHigh	= new byte[]{message[16], message[17]};
		signature	 	= new byte[]{message[18], message[19], message[20], message[21], message[22], message[23], message[24], message[25]};
		reserved		= new byte[]{message[26], message[27]};
		treeID			= new byte[]{message[28], message[29]};
		processID		= new byte[]{message[30], message[31]};
		userID			= new byte[]{message[32], message[33]};
		multiplexID		= new byte[]{message[34], message[35]};
	}
	
	/**
	 * Wraps the Netbios header around a response
	 * @param response that is wrapped
	 * @return wrapped response
	 */
	private byte[] wrapNetbios(byte[] response) {
		byte[] netbios = {0x00};
		byte[] buffer = ByteBuffer.allocate(4).putInt(response.length).array();	// allocate(4) because int is 4 bytes long
		byte[] netbiosLength = {buffer[1], buffer[2], buffer[3]};			// only bytes 1-3 needed, byte 0 is not needed
		return HelperUtils.concat(netbios, netbiosLength, response);
	}
	
	/**
	 * Wraps the header around a response
	 * @param response that is wrapped
	 * @return wrapped response
	 */
	private byte[] wrapHeader(byte[] response) {
		byte[] header = new byte[0];
		return HelperUtils.concat(header, serverComp, smbCommand, ntStat, smbFlags, smbFlags2, processIDHigh, signature,
								reserved, treeID, processID, userID, multiplexID, response);
	}
	
	/**
	 * Builds the negotiate packet
	 * @return negotiate packet
	 */
	private Packet getNego() {
		byte[] wordCount	= {0x11};
		byte[] dialect		= evaluateDialect();		
		byte[] secMode		= {0x03};
		byte[] maxMpxC 		= {0x32, 0x00};
		byte[] maxVcs		= {0x01, 0x00};
		byte[] maxBufSize	= {0x04, 0x11, 0x00, 0x00};
		byte[] maxRawBuf	= {0x00, 0x00, 0x01, 0x00};
		byte[] sessionKey	= {0x00, 0x00, 0x00, 0x00};
		byte[] capabilities	= {(byte) 0xfc, (byte) 0xe3, 0x01, (byte) 0x80};
		byte[] sysTime		= getTimeInBytes();
		byte[] timeZone		= getTimeZoneInBytes();
		byte[] keyLength	= {0x00};
		byte[] byteCount	= {0x3a, 0x00};			
		byte[] guid			= serverGUID;
		byte[] secBlob		= {0x60, 0x28, 0x06, 0x06};
		byte[] oid			= {0x2b, 0x06, 0x01, 0x05, 0x05, 0x02};
		byte[] protectNeg	= {(byte) 0xa0, 0x1e};
		byte[] negToken		= {0x30, 0x1c, (byte) 0xa0, 0x1a, 0x30, 0x18};
		byte[] mechType		= {0x06, 0x0a, 0x2b, 0x06, 0x01, 0x04, 0x01, (byte) 0x82, 0x37, 0x02, 0x02, 0x1e};
		byte[] mechType2	= {0x06, 0x0a, 0x2b, 0x06, 0x01, 0x04, 0x01, (byte) 0x82, 0x37, 0x02, 0x02, 0x0a};
		
		byte[] response = HelperUtils.concat(wordCount, dialect, secMode, maxMpxC, maxVcs, maxBufSize, maxRawBuf,
						sessionKey, capabilities, sysTime, timeZone, keyLength, byteCount, guid, secBlob, oid,
						protectNeg, negToken, mechType, mechType2);
		return new Packet(wrapNetbios(wrapHeader(response)));
	}
	
	/**
	 * Evaluates what Dialects are offered by the client and which position the used NT LM 0.12 dialect is at
	 * @return position of the NT LM 0.12 dialect
	 */
	private byte[] evaluateDialect() {
		byte[] dialectMsg = new byte[message.length-39];
		System.arraycopy(message, 39, dialectMsg, 0, message.length - 39);
		short dialectNumber = 0;
		for(int i = 0, start = 0; i < dialectMsg.length; i++) {
			if(dialectMsg[i] == 0x00) {
				byte[] dialect = new byte[i-start];
				System.arraycopy(dialectMsg, start, dialect, 0, i-start);
				if(HelperUtils.byteToStr(dialect).contains("NT LM 0.12")) {
					return new byte[]{(byte)dialectNumber, (byte)(dialectNumber >> 8)};
				}
				start = i+1;
				dialectNumber++;
			}
		}
		return new byte[]{0x00, 0x00};
	}
	
	/**
	 * Builds the session setup packet
	 * @ret	urn session setup packet
	 */
	private Packet getSessSetup() {
		if(authenticateNext) {
			return new Packet(getSetupAuth());
		} else {
			authenticateNext = true;
			return new Packet(getSetupChal());
		}
	}
	
	/**
	 * Builds the session setup challange packet
	 * @return session setup challange packet
	 */
	private byte[] getSetupChal() {
		byte[] wordCount			= {0x04};
		byte[] andXCommand			= {(byte) 0xff};
		byte[] reserved				= {0x00};
		byte[] andXOffset			= {0x60, 0x01};
		byte[] action				= {0x00, 0x00};
		byte[] secBlobLength;
		byte[] byteCount;
		byte[] secBlob				= {(byte) 0xa1, (byte) 0x81, (byte) 0xc4};
		byte[] negToken				= {0x30, (byte) 0x81, (byte) 0xc1, (byte) 0xa0, 0x03, 0x0a, 0x01};
		byte[] negResult			= {0x01};
		byte[] negToken2			= {(byte) 0xa1, 0x0c, 0x06, 0x0a};
		byte[] supportedMech		= {0x2b, 0x06, 0x01, 0x04, 0x01, (byte) 0x82, 0x37, 0x02, 0x02, 0x0a};
		byte[] negToken3			= {(byte) 0xa2, (byte) 0x81, (byte) 0xab, 0x04, (byte) 0x81, (byte) 0xa8};
		byte[] ntlmsspId			= {0x4e, 0x54, 0x4c, 0x4d, 0x53, 0x53, 0x50, 0x00};
		byte[] nlmMsgType			= {0x02, 0x00, 0x00, 0x00};
		byte[] buffer				= ByteBuffer.allocate(4).putInt(serverName.length).array();
		byte[] targetNameLength		= new byte[]{buffer[3], buffer[2]};
		byte[] targetNameMaxLength	= new byte[]{buffer[3], buffer[2]}; 
		byte[] targetNameOffset		= {0x38, 0x00, 0x00, 0x00};
		byte[] flags				= {0x15, (byte) 0x82, (byte) 0x8a, 0x60};
		if(!serverVersion[0].contains("Unix")) {
			flags[3] = (byte) (flags[3] | 0x02);
		}
		byte[] challenge			= HelperUtils.randomBytes(8);
		byte[] reserved2			= {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
		byte[] targetInfoLength		= {0x60, 0x00};
		byte[] targetInfoMaxLength	= {0x60, 0x00};
		byte[] targetInfoOffset		= {0x48, 0x00, 0x00, 0x00};
		byte[] version = null;
		if(serverVersion[0].contains("Windows 7") || serverVersion[0].contains("Windows Server 2008")) {
			version = new byte[]{0x06, 0x01, (byte) 0xb0, 0x1d, 0x00, 0x00, 0x00, 0x0f};
		} else if(serverVersion[0].contains("Windows 8") || serverVersion[0].contains("Windows Server 2012")) {
			version = new byte[]{0x06, 0x02, (byte) 0xf0, 0x23, 0x00, 0x00, 0x00, 0x0f};
		}
		// serverName
		byte[] attributeNBDomain	= {0x02, 0x00, 0x10, 0x00};
		// serverName	
		byte[] attributeNBcomputer	= {0x01, 0x00, 0x10, 0x00};
		// serverName	
		byte[] attributeDNSDomain	= {0x04, 0x00, 0x10, 0x00};
		// serverName
		byte[] attributeDNScomputer	= {0x03, 0x00, 0x10, 0x00};
		// serverName
		byte[] attributeTimeStamp   = {0x07, 0x00, 0x08, 0x00};
		byte[] timeStamp = getTimeInBytes();
		byte[] attributeEnd			= {0x00, 0x00, 0x00, 0x00};
		secBlob						= HelperUtils.concat(secBlob, negToken, negResult, negToken2, supportedMech, negToken3,
											ntlmsspId, nlmMsgType, targetNameLength, targetNameMaxLength, targetNameOffset,
											flags, challenge, reserved2, targetInfoLength, targetInfoMaxLength, targetInfoOffset,
											version, serverName, attributeNBDomain, serverName, attributeNBcomputer, serverName,
											attributeDNSDomain, serverName, attributeDNScomputer, serverName, attributeTimeStamp,
											timeStamp, attributeEnd);
		byte[] nativOS				= HelperUtils.fillWithZeroExtended(serverVersion[0].getBytes());
		byte[] nativLanMngr			= HelperUtils.fillWithZeroExtended(serverVersion[1].getBytes());
		buffer						= ByteBuffer.allocate(4).putInt(secBlob.length).array();
		secBlobLength				= new byte[]{buffer[3], buffer[2]};
		buffer						= ByteBuffer.allocate(4).putInt(secBlob.length + nativOS.length + nativLanMngr.length).array();
		byteCount					= new byte[]{buffer[3], buffer[2]};
		
		ntStat 					= new byte[]{0x16, 0x00, 0x00, (byte) 0xc0};
		userID					= new byte[]{0x00, 0x08};
		
		byte[] response = HelperUtils.concat(wordCount, andXCommand, reserved, andXOffset, action, secBlobLength,
											byteCount, secBlob, nativOS, nativLanMngr);
		return wrapNetbios(wrapHeader(response));
	}
	
	/**
	 * Builds the session setup packet for authentication required
	 * @return session setup authentication packet
	 */
	private byte[] getSetupAuth() {
		byte[] wordCount		= {0x04};
		byte[] andXCommand		= {(byte) 0xff};
		byte[] reserved			= {0x00};
		byte[] andXOffset		= {(byte) 0xa2, 0x00};
		byte[] action			= {0x01, 0x00};
		byte[] secBlobLength;
		byte[] byteCount;
		byte[] secBlob			= {(byte) 0xa1, 0x07, 0x30, 0x05, (byte) 0xa0, 0x03, 0x0a, 0x01, 0x00};
		byte[] nativOS			= HelperUtils.fillWithZeroExtended(serverVersion[0].getBytes());
		byte[] nativLanMngr		= HelperUtils.fillWithZeroExtended(serverVersion[1].getBytes());
		
		byte[] buffer				= ByteBuffer.allocate(4).putInt(secBlob.length).array();
		secBlobLength				= new byte[]{buffer[3], buffer[2]};
		buffer						= ByteBuffer.allocate(4).putInt(secBlob.length + nativOS.length + nativLanMngr.length).array();
		byteCount					= new byte[]{buffer[3], buffer[2]};
		
		byte[] response = HelperUtils.concat(wordCount, andXCommand, reserved, andXOffset, action, secBlobLength,
				byteCount, secBlob, nativOS, nativLanMngr);
		return wrapNetbios(wrapHeader(response));
	}
	
	/**
	 * Builds the tree connect packet
	 * @return tree connect packet
	 */
	private Packet getTreeCon() {
		String str 			= HelperUtils.byteToStr(message);
		byte[] wordCount	= {0x00};
		byte[] andXCommand	= {0x00, 0x00};
		byte[] response 	= null;
		if(str.contains("IPC$") || str.contains("C$")) {
			wordCount			= new byte[] {0x07};
			andXCommand			= new byte[] {(byte) 0xff};
			byte[] reserved				= {0x00};
			byte[] andXOffset			= {0x38, 0x00};
			byte[] optionalSupport		= {0x01, 0x00};
			byte[] maxShareAccess		= {(byte) 0xff, (byte) 0xff, 0x1f, 0x00};
			byte[] guestMaxShareAccess	= {(byte) 0xff, (byte) 0xff, 0x1f, 0x00};
			byte[] byteCount			= {0x07, 0x00};
			byte[] service				= {0x49, 0x50, 0x43, 0x00};
			byte[] extraParameters		= {0x00, 0x00, 0x00};
		
			treeID						= new byte[]{0x00, 0x08};
						
			response = HelperUtils.concat(wordCount, andXCommand, reserved, andXOffset, optionalSupport, maxShareAccess,
											guestMaxShareAccess, byteCount, service, extraParameters);
		} else if(str.contains("ADMIN$")) {
			ntStat = new byte[] {0x22, 0x00, 0x00, (byte) 0xc0};
			response = HelperUtils.concat(wordCount, andXCommand);
		} else {
			ntStat = new byte[] {(byte) 0xcc, 0x00, 0x00, (byte) 0xc0};
			response = HelperUtils.concat(wordCount, andXCommand);
		}
		
		return new Packet(wrapNetbios(wrapHeader(response)));
	}
	
	/**
	 * Builds the nt create packet
	 * @return nt create packet
	 */
	private Packet getNTCreate() {
		byte[] wordCount		= {0x22};
		byte[] andXCommand		= {(byte) 0xff};
		byte[] reserved			= {0x00};
		byte[] andXOffset		= {0x67, 0x00};
		byte[] oplockLevel		= {0x00};
		byte[] fid				= {(byte) 0x00, 0x40};
		byte[] createAction		= {0x01, 0x00, 0x00, 0x00};
		byte[] created			= {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
		byte[] lastAccess		= {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
		byte[] lastWrite		= {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
		byte[] change			= {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
		byte[] fileAttributes	= {(byte) 0x80, 0x00, 0x00, 0x00};
		byte[] allocationSize	= {0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
		byte[] endOfFile		= {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
		byte[] fileType			= {0x02, 0x00};
		byte[] ipcState			= {(byte) 0xff, 0x05};
		byte[] isDirectory		= {0x00};
		byte[] byteCount		= {0x00, 0x00};
		
		byte[] response = HelperUtils.concat(wordCount, andXCommand, reserved, andXOffset, oplockLevel, fid,
											createAction, created, lastAccess, lastWrite, change, fileAttributes, allocationSize,
											endOfFile, fileType, ipcState, isDirectory, byteCount);
		return new Packet(wrapNetbios(wrapHeader(response)));
	}
	
	/**
	 * Builds the trans packet
	 * @return trans packet
	 */
	private Packet getTrans() {
		byte[] transSub	= getTransSub();
		byte[] response = null;
		if(transSub[0] == 0x00 && transSub[1] == 0x0b) { //bind_ack
			byte[] wordCount		= {0x0a};
			byte[] totalParamCount	= {0x00,0x00};
			byte[] totalDataCount	= {0x44,0x00};
			byte[] reserved			= {0x00, 0x00};
			byte[] paramCount		= {0x00, 0x00};
			byte[] paramOffset		= {0x38, 0x00};
			byte[] paramDisplace	= {0x00, 0x00};
			byte[] dataCount		= {0x44, 0x00};
			byte[] dataOffset		= {0x38, 0x00};
			byte[] dataDisplace		= {0x00, 0x00};
			byte[] setupCount		= {0x00};
			byte[] reserved2		= {0x00};
			byte[] byteCount		= {0x45, 0x00};
			byte[] padding			= {0x00};
			
			byte[] dcerpc			= getDceRpc(transSub, 0); 
			
			response = HelperUtils.concat(wordCount, totalParamCount, totalDataCount, reserved, paramCount, paramOffset,
												paramDisplace, dataCount, dataOffset, dataDisplace, setupCount, reserved2, byteCount, padding, dcerpc);
			
		} else if(transSub[0] == 0x00 && transSub[1] == 0x00) { //netShareEnumAll
			byte[] wordCount		= {0x0a};
			byte[] totalParamCount	= {0x00, 0x00};
			byte[] totalDataCount	= {0x20, 0x01};
			byte[] reserved			= {0x00, 0x00};
			byte[] paramCount		= {0x00, 0x00};
			byte[] paramOffset		= {0x38, 0x00};
			byte[] paramDisplace	= {0x00, 0x00};
			byte[] dataCount		= {0x20, 0x01};
			byte[] dataOffset		= {0x38, 0x00};
			byte[] dataDisplace		= {0x00, 0x00};
			byte[] setupCount		= {0x00};
			byte[] reserved2		= {0x00};
			byte[] byteCount		= new byte[2]/*= {0x21, 0x01}*/;
			byte[] padding			= {0x00};
			
			byte[] dcerpc			= new byte[24];
			
			byte[] levelPointer		= {0x01, 0x00, 0x00, 0x00};
			byte[] ctr				= {0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00};
			byte[] ctr1				= {0x03, 0x00, 0x00, 0x00, 0x04, 0x00, 0x02, 0x00, 0x03, 0x00, 0x00, 0x00};
			byte[] array1Pointer	= {0x08, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, (byte) 0x80, 0x0c, 0x00, 0x02, 0x00};
			byte[] array2Pointer	= {0x10, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, (byte) 0x80, 0x14, 0x00, 0x02, 0x00};
			byte[] array3Pointer	= {0x18, 0x00, 0x02, 0x00, 0x03, 0x00, 0x00, (byte) 0x80, 0x1c, 0x00, 0x02, 0x00};
			byte[] array1			= {0x07, 0x00,0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00, 0x00, 0x41, 0x00, 0x44, 0x00, 0x4d, 0x00, 
										0x49, 0x00, 0x4e, 0x00, 0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0d, 0x00, 0x00, 0x00, 0x00, 0x00, 
										0x00, 0x00, 0x0d, 0x00, 0x00, 0x00, 0x52, 0x00, 0x65, 0x00, 0x6d, 0x00, 0x6f, 0x00, 0x74, 0x00, 
										0x65, 0x00, 0x20, 0x00, 0x41, 0x00, 0x64, 0x00, 0x6d, 0x00, 0x69, 0x00, 0x6e, 0x00, 0x00, 0x00};
			byte[] array2			= {0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x43, 0x00, 
										0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0e, 0x00, 
										0x00, 0x00, 0x44, 0x00, 0x65, 0x00, 0x66, 0x00, 0x61, 0x00, 0x75, 0x00, 0x6c, 0x00, 0x74, 0x00, 
										0x20, 0x00, 0x73, 0x00, 0x68, 0x00, 0x61, 0x00, 0x72, 0x00, 0x65, 0x00};
			byte[] array3			= {0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0x00, 
										0x00, 0x00, 0x49, 0x00, 0x50, 0x00, 0x43, 0x00, 0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0b, 0x00, 
									0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0b, 0x00, 0x00, 0x00, 0x52, 0x00, 0x65, 0x00, 0x6d, 0x00, 
										0x6f, 0x00, 0x74, 0x00, 0x65, 0x00, 0x20, 0x00, 0x49, 0x00, 0x50, 0x00, 0x43, 0x00, 0x00, 0x00};
			byte[] totalEntries		= {0x00, 0x00, 0x03, 0x00, 0x00, 0x00};
			byte[] referentID		= {0x20, 0x00, 0x02, 0x00};
			byte[] resumeHandle		= {0x00, 0x00, 0x00, 0x00};
			byte[] windowsError		= {0x00, 0x00, 0x00, 0x00};
			int tmp					= padding.length + dcerpc.length + levelPointer.length + ctr.length + ctr1.length
										+ array1Pointer.length + array2Pointer.length + array3Pointer.length + array1.length
										+ array2.length + array3.length + totalEntries.length + referentID.length + resumeHandle.length
										+ windowsError.length;
			byte[] tmp2				= ByteBuffer.allocate(4).putInt(tmp).array();
			byteCount				= new byte[] {tmp2[3], tmp2[2]};
			dcerpc					= getDceRpc(transSub, tmp-1);

			response = HelperUtils.concat(wordCount, totalParamCount, totalDataCount, reserved, paramCount, paramOffset,
											paramDisplace, dataCount, dataOffset, dataDisplace, setupCount, reserved2, byteCount, padding, dcerpc,
											levelPointer, ctr, ctr1, array1Pointer, array2Pointer, array3Pointer, 
											array1, array2, array3, totalEntries, referentID, resumeHandle, windowsError);	
		}
			
		return new Packet(wrapNetbios(wrapHeader(response)));		
	}
		
	/**
	 * Builds the DCERPC packet
	 * @return DCERPC packet
	 */
	private byte[] getDceRpc(byte[] transSub, int length) {
		byte[] majorVersion	= {0x05};
		byte[] minorVersion	= {0x00};
		byte[] packetType	= null;
		byte[] packetFlags	= {0x03};
		byte[] dataRepres	= {0x10, 0x00, 0x00, 0x00};
		byte[] fragLength	= null;
		byte[] authLength	= {0x00, 0x00};
		byte[] callID		= null;
		byte[] response		= null;
			
		if(transSub[0] == 0x00 && transSub[1] == 0x0b) {
			packetType	= new byte[]{0x0c};
			fragLength	= new byte[]{0x44, 0x00};
			callID		= new byte[]{0x01, 0x00, 0x00, 0x00};
			byte[] maxXmitFrag		= {(byte) 0xb8, 0x10};
			byte[] maxRecvFrag		= {(byte) 0xb8, 0x10};
			byte[] assocGroup		= {0x4a, 0x41, 0x00, 0x00};
			byte[] scndryAddrLen	= {0x0d, 0x00};
			byte[] scndryAddr		= {0x5c, 0x50, 0x49, 0x50, 0x45, 0x5c, 0x73, 0x72, 
												0x76, 0x73, 0x76, 0x63, 0x00, 0x00};
			byte[] numResults		= {0x01, 0x00, 0x00, 0x00};
			byte[] ctxItem			= {0x00, 0x00, 0x00, 0x00, 0x04, 0x5d, (byte) 0x88, (byte) 0x8a,
												(byte) 0xeb, 0x1c, (byte) 0xc9, 0x11, (byte) 0x9f, (byte) 0xe8,
												0x08, 0x00, 0x2b, 0x10, 0x48, 0x60, 0x02, 0x00,	0x00, 0x00};
			
			response = HelperUtils.concat(majorVersion, minorVersion, packetType, packetFlags, dataRepres,fragLength,
					authLength, callID, maxXmitFrag, maxRecvFrag, assocGroup, scndryAddrLen, scndryAddr, numResults, ctxItem);
		} else if(transSub[0] == 0x00 && transSub[1] == 0x00) {
			packetType	= new byte[]{0x02};
			byte[] tmp	= ByteBuffer.allocate(4).putInt(length).array();
			fragLength	= new byte[]{tmp[3], tmp[2]};
			callID		= new byte[]{0x02, 0x00, 0x00, 0x00};
			tmp			= ByteBuffer.allocate(4).putInt(length-24).array();
			byte[] allocHint	= new byte[]{tmp[3], tmp[2], tmp[1], tmp[0]};
			byte[] contextID	= {0x00, 0x00};
			byte[] cancelCount	= {0x00, 0x00};
			
			response = HelperUtils.concat(majorVersion, minorVersion, packetType, packetFlags, dataRepres,fragLength,
					authLength, callID, allocHint, contextID, cancelCount);
		}			
		return response;
	}
	
	/**
	 * Builds the close packet
	 * @return close packet
	 */
	private Packet getClose() {
		byte[] wordCount	= {0x00};
		byte[] byteCount	= {0x00, 0x00};
		
		smbCommand			= new byte[]{0x04};
		
		byte[] response = HelperUtils.concat(wordCount, byteCount);
		
		return new Packet(wrapNetbios(wrapHeader(response)));
	}
	
	/**
	 * Builds the tree disconnect packet
	 * @return tree disconnect packet
	 */
	private Packet getTreeDisc() {
		byte[] wordCount	= {0x00};
		byte[] byteCount	= {0x00, 0x00};
		
		smbCommand[0] = 0x71;
		
		byte[] response = HelperUtils.concat(wordCount, byteCount);
		
		return new Packet(wrapNetbios(wrapHeader(response)));
	}
	
	/**
	 * Builds the echo packet
	 * @return echo packet
	 */
	private Packet getEcho() {
		byte[] wordCount	= {0x01};
		byte[] echoSeq		= {0x01, 0x00};
		byte[] byteCount	= {0x10, 0x00};
		byte[] echoData		= {(byte) 0xf0, (byte) 0xf0, (byte) 0xf0, (byte) 0xf0, (byte) 0xf0, (byte) 0xf0, (byte) 0xf0, (byte) 0xf0,
								(byte) 0xf0, (byte) 0xf0, (byte) 0xf0, (byte) 0xf0, (byte) 0xf0, (byte) 0xf0, (byte) 0xf0, (byte) 0xf0}; 
		byte[] response = HelperUtils.concat(wordCount, echoSeq, byteCount, echoData);
		return new Packet(wrapNetbios(wrapHeader(response)));
	}
	
	/**
	 * Builds the trans2 packet
	 * @return trans2 packet
	 */
	private Packet getTrans2() {
		byte[] response = null;		
		byte[] wordCount	= {0x00};
		byte[] andXCommand	= {0x00, 0x00};
		ntStat = new byte[] {0x22, 0x00, 0x00, (byte) 0xc0};
		response = HelperUtils.concat(wordCount, andXCommand);
		return new Packet(wrapNetbios(wrapHeader(response)));
	}
	
	/**
	 * Extracts the trans sub packet from message
	 * @return trans sub packet
	 */		
	private byte[] getTransSub() {
		byte[] transSub = new byte[2];
		if(smbCommand[0] == 0x32) transSub = new byte[]{message[66], message[65]};
		else if(smbCommand[0] == 0x25) transSub = new byte[]{0x00, message[90]};
		else transSub = new byte[]{0x00, 0x00};
		return transSub;
	}
	/**
	 * Returns the command number from the current message
	 * @return command number
	 */
	private byte getSmbCommand() {
		return smbCommand[0];
	}
	
	//message constants
	private static final byte SMB_COM_CLOSE                  = 0x04;
	private static final byte SMB_COM_TRANSACTION            = 0x25;
	private static final byte SMB_COM_ECHO                   = 0x2B;
	private static final byte SMB_COM_TRANSACTION2           = 0x32;
	private static final byte SMB_COM_TREE_DISCONNECT        = 0x71;
	private static final byte SMB_COM_NEGOTIATE              = 0x72;
	private static final byte SMB_COM_SESSION_SETUP_ANDX     = 0x73;
	private static final byte SMB_COM_TREE_CONNECT_ANDX      = 0x75;
	private static final byte SMB_COM_NT_CREATE_ANDX         = (byte) 0xA2;
	
}