hostage/src/de/tudarmstadt/informatik/hostage/protocol/SMB.java

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.List;
import java.util.TimeZone;

import de.tudarmstadt.informatik.hostage.commons.HelperUtils;
import de.tudarmstadt.informatik.hostage.wrapper.ByteArray;

/**
 * SMB protocol
 * @author Wulf Pfeiffer
 */
public class SMB implements Protocol<ByteArray> {
	/**
	 * 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;
	
	
	public int getPort() {
		return 445;
	}

	
	public TALK_FIRST whoTalksFirst() {
		return TALK_FIRST.CLIENT;
	}
	
	private SMBPacket packet = new SMBPacket();

	
	public List<ByteArray> processMessage(ByteArray message) {
		if(message != null)
			lastMessage = message.get();
		packet.newMsg(lastMessage);
		byte smbCommand = packet.getSmbCommand();
		List<ByteArray> response = new ArrayList<ByteArray>();

		switch (state) {
		case NONE:
			if (smbCommand == 0x72) {
				state = STATE.CONNECTED;
				response.add(new ByteArray(packet.getNego()));
			} else {
				state = STATE.DISCONNECTED;
				response.add(new ByteArray(packet.getTreeDisc()));
			}
			break;
		case CONNECTED:
			if (smbCommand == 0x73) {
				response.add(new ByteArray(packet.getSessSetup()));
			} else if (smbCommand == 0x75) {
				state = STATE.AUTHENTICATED;
				response.add(new ByteArray(packet.getTreeCon()));
			} else {
				state = STATE.DISCONNECTED;
				response.add(new ByteArray(packet.getTreeDisc()));
			}
			break;
		case AUTHENTICATED:
			if (smbCommand == (byte) 0xa2) {
				state = STATE.LISTING;
				response.add(new ByteArray(packet.getNTCreate()));
			} else if (smbCommand == 0x2b) {
				response.add(new ByteArray(packet.getEcho()));
			} else if (smbCommand == 0x32) {
				response.add(new ByteArray(packet.getTrans2()));
			} else if (smbCommand == 0x04) {
				response.add(new ByteArray(packet.getClose()));
			} else if (smbCommand == 0x71) {
				state = STATE.CLOSED;
				response.add(new ByteArray(packet.getTreeDisc()));
			} else {
				state = STATE.DISCONNECTED;
				response.add(new ByteArray(packet.getTreeDisc()));
			}
			break;
		case LISTING:
			if (smbCommand == 0x25) {
				response.add(new ByteArray(packet.getTrans()));
			} else if (smbCommand == 0x04) {
				response.add(new ByteArray(packet.getClose()));
			} else if (smbCommand == 0x71) {
				state = STATE.CLOSED;
				response.add(new ByteArray(packet.getTreeDisc()));
			} else if (smbCommand == 0x72) {
				state = STATE.CONNECTED;
				response.add(new ByteArray(packet.getNego()));
			} else {
				state = STATE.DISCONNECTED;
				response.add(new ByteArray(packet.getTreeDisc()));
			}
			break;
		case DISCONNECTED:
			state = STATE.CLOSED;
			response.add(new ByteArray(packet.getTreeDisc()));
			break;
		default:
			state = STATE.CLOSED;
			response.add(new ByteArray(packet.getTreeDisc()));
		}
		return response;
	}

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

	
	public boolean isSecure() {
		return false;
	}

	
	public Class<ByteArray> getType() {
		return ByteArray.class;
	}

	
	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 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[] b = new byte[8];
		byte[] b2 = ByteBuffer.allocate(8).putLong(time).array();

		for (int i = 0, j = 7; i < 8 && j > -1; i++, j--) {
			b[i] = (byte) (b2[j] & 0xff);
		}

		return b;
	}
	
	/**
	 * Generates a random byte[] of a specified size
	 * @param size of the byte[]
	 * @return random byte[]
	 */
	private byte[] randomBytes(int size) {
		byte[] bytes = new byte[size];
		SecureRandom rdm = new SecureRandom();
		rdm.nextBytes(bytes);
		return bytes;
	}

	/**
	 * Denotes a SMB packet
	 */
	private class SMBPacket {
		private SecureRandom rndm 					= new SecureRandom();
		private String[][] possibleVersions 	= { {"Windows Server 2008 R2 Enterprise 7600","Windows Server 2008 R2 Enterprise 6.1"},
													{"Windows 7 Professional 7600","Windows 7 Professional 6.1"},
													{"Windows 8 Enterprise 9200", "Windows 8 Enterprise 9200"},
													{"Windows Server 2012 Standard 6.2", "Windows Server 2012 Standard 6.2"},
//													{"Unix", "Samba"}
		};
		private byte[] serverName 				= fillWithZero("lalalalalala".getBytes());
		private final String[] serverVersion	= possibleVersions[rndm.nextInt(possibleVersions.length)];
		private byte[] message					= null; 
		private final byte[] serverGUID			= 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];
				
		/** Constructor */
		public SMBPacket() {}
		
		/**
		 * Breaks a message from the client down into its components
		 * @param message that is analyzed
		 */
		public void newMsg(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
		 */
		public byte[] 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		= {(byte) 0x88, (byte) 0xff};		//FIXME correct time zone
			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 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
		 * @return session setup packet
		 */
		public byte[] getSessSetup() {
			if(authenticateNext) return getSetupAuth();
			else {
				authenticateNext = true;
				return 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, 0x62};
			byte[] challenge			= 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				= fillWithZeroExtended(serverVersion[0].getBytes());
			byte[] nativLanMngr			= 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			= fillWithZeroExtended(serverVersion[0].getBytes());
			byte[] nativLanMngr		= 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
		 */
		public byte[] getTreeCon() {
			String str 			= toString();
			byte[] wordCount	= {0x00};
			byte[] andXCommand	= {0x00, 0x00};
			byte[] response 	= null;
			
			if(str.contains("IPC$") || str.contains("DOCS")) {
				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("C$") || str.contains("ADMIN$")) {
				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 wrapNetbios(wrapHeader(response));
		}
		
		/**
		 * Builds the nt create packet
		 * @return nt create packet
		 */
		public byte[] 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 wrapNetbios(wrapHeader(response));
		}
		
		/**
		 * Builds the trans packet
		 * @return trans packet
		 */
		public byte[] getTrans() {
			byte[] transSub	= getTransSub();
			byte[] response = null;
			if(transSub[0] == 0x00 && transSub[1] == 0x0b) {
				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			= {0x05, 0x00, 
											0x0c, 0x03, 0x10, 0x00, 0x00, 0x00, 0x44, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, (byte) 0xb8, 0x10, 
											(byte) 0xb8, 0x10, 0x4a, 0x41, 0x00, 0x00, 0x0d, 0x00, 0x5c, 0x50, 0x49, 0x50, 0x45, 0x5c, 0x73, 0x72, 
											0x76, 0x73, 0x76, 0x63, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 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(wordCount, totalParamCount, totalDataCount, reserved, paramCount, paramOffset,
													paramDisplace, dataCount, dataOffset, dataDisplace, setupCount, reserved2, byteCount, padding, dcerpc);
				
			} else if(transSub[0] == 0x00 && transSub[1] == 0x00) {
				byte[] wordCount		= {0x0a};
				byte[] totalParamCount	= {0x00, 0x00};
				byte[] totalDataCount	= {0x54, 0x01};
				byte[] reserved			= {0x00, 0x00};
				byte[] paramCount		= {0x00, 0x00};
				byte[] paramOffset		= {0x38, 0x00};
				byte[] paramDisplace	= {0x00, 0x00};
				byte[] dataCount		= {0x54, 0x01};
				byte[] dataOffset		= {0x38, 0x00};
				byte[] dataDisplace		= {0x00, 0x00};
				byte[] setupCount		= {0x00};
				byte[] reserved2		= {0x00};
				byte[] byteCount		= {0x55, 0x01};
				byte[] padding			= {0x00};
				
				byte[] dcerpc			= {0x05, 0x00, 
											0x02, 0x03, 0x10, 0x00, 0x00, 0x00, 0x54, 0x01, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x3c, 0x01, 
											0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
				byte[] serverService	= {0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 
											0x02, 0x00, 0x04, 0x00, 0x00, 0x00, 0x04, 0x00, 0x02, 0x00, 0x04, 0x00, 0x00, 0x00, 0x08, 0x00, 
											0x02, 0x00, 0x00, 0x00, 0x00, (byte) 0x80, 0x0c, 0x00, 0x02, 0x00, 0x10, 0x00, 0x02, 0x00, 0x00, 0x00, 
											0x00, (byte) 0x80, 0x14, 0x00, 0x02, 0x00, 0x18, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1c, 0x00, 
											0x02, 0x00, 0x20, 0x00, 0x02, 0x00, 0x03, 0x00, 0x00, (byte) 0x80, 0x24, 0x00, 0x02, 0x00, 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, 
											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, 0x00, 0x00, 0x05, 0x00, 
											0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x64, 0x00, 0x6f, 0x00, 0x63, 0x00, 
											0x73, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 
											0x00, 0x00, 0x00, 0x00, 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, 0x04, 0x00, 0x00, 0x00};
				byte[] referentID		= {0x28, 0x00, 0x02, 0x00};
				byte[] resumeHandle		= {0x00, 0x00, 0x00, 0x00};
				byte[] windowsError		= {0x00, 0x00, 0x00, 0x00};

				response = HelperUtils.concat(wordCount, totalParamCount, totalDataCount, reserved, paramCount, paramOffset,
													paramDisplace, dataCount, dataOffset, dataDisplace, setupCount, reserved2, byteCount, padding, dcerpc,
													serverService, totalEntries, referentID, resumeHandle, windowsError);
				
				
			}
			
			return wrapNetbios(wrapHeader(response));		
		}
		
		/**
		 * Builds the close packet
		 * @return close packet
		 */
		public byte[] getClose() {
			byte[] wordCount	= {0x00};
			byte[] byteCount	= {0x00, 0x00};
			
			smbCommand			= new byte[]{0x04};
			
			byte[] response = HelperUtils.concat(wordCount, byteCount);
			
			return wrapNetbios(wrapHeader(response));
		}
		
		/**
		 * Builds the tree disconnect packet
		 * @return tree disconnect packet
		 */
		public byte[] getTreeDisc() {
			byte[] wordCount	= {0x00};
			byte[] byteCount	= {0x00, 0x00};
			
			smbCommand[0] = 0x71;
			
			byte[] response = HelperUtils.concat(wordCount, byteCount);
			
			return wrapNetbios(wrapHeader(response));
		}
		
		/**
		 * Builds the echo packet
		 * @return echo packet
		 */
		public byte[] 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 wrapNetbios(wrapHeader(response));

		}
		
		/**
		 * Builds the trans2 packet
		 * @return trans2 packet
		 */
		public byte[] 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 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;
		}

		public String toString() {
			return HelperUtils.byteToStr(message);
		}
		
		/**
		 * Returns the command number from the current message
		 * @return command number
		 */
		public byte getSmbCommand() {
			return smbCommand[0];
		}
		
		/**
		 * Puts a 0x00 byte between each byte and another 2 0x00 bytes at the end of a byte array.
		 * @param bytes that need to be filled with 0x00.
		 * @return filled byte array.
		 */
		private byte[] fillWithZeroExtended(byte[] bytes) {
			byte[] zeroBytes = fillWithZero(bytes);
			byte[] newBytes = new byte[zeroBytes.length+2];
			newBytes = HelperUtils.concat(zeroBytes, new byte[]{0x00, 0x00});
			return newBytes;
		}
		
		/**
		 * Puts a 0x00 byte between each byte in a byte array.
		 * @param bytes that need to be filled with 0x00.
		 * @return filled byte array.
		 */
		private byte[] fillWithZero(byte[] bytes) {
			byte[] newBytes = new byte[(bytes.length * 2)];
			for(int i = 0, j = 0; i < bytes.length && j < newBytes.length; i++, j=j+2) {
				newBytes[j] = bytes[i];
				newBytes[j+1] = 0x00;
			}
			return newBytes;
		}
	}
}