Added Web based RDP support with NLA, #3867 and #3914

rdp/protocol/tpkt.js

@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 2014-2015 Sylvain Peyrefitte
+ *
+ * This file is part of node-rdpjs.
+ *
+ * node-rdpjs is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+var inherits = require('util').inherits;
+var type = require('../core').type;
+var events = require('events');
+
+/**
+ * Type of tpkt packet
+ * Fastpath is use to shortcut RDP stack
+ * @see http://msdn.microsoft.com/en-us/library/cc240621.aspx
+ * @see http://msdn.microsoft.com/en-us/library/cc240589.aspx
+ */
+var Action = {
+	FASTPATH_ACTION_FASTPATH : 0x0,
+    FASTPATH_ACTION_X224 : 0x3
+};
+
+/**
+ * TPKT layer of rdp stack
+ */
+function TPKT(transport) {
+	this.transport = transport;
+	// wait 2 bytes
+	this.transport.expect(2);
+	// next state is receive header
+	var self = this;
+	this.transport.once('data', function(s) {
+		self.recvHeader(s);
+	}).on('close', function() {
+		self.emit('close');
+	}).on('error', function (err) {
+		self.emit('error', err);
+	});
+}
+
+/**
+ * inherit from a packet layer
+ */
+inherits(TPKT, events.EventEmitter);
+
+/**
+ * Receive correct packet as expected
+ * @param s {type.Stream}
+ */
+TPKT.prototype.recvHeader = function (s) {
+	var version = new type.UInt8().read(s).value;
+	var self = this;
+	if(version === Action.FASTPATH_ACTION_X224) {
+		new type.UInt8().read(s);
+		this.transport.expect(2);
+		this.transport.once('data', function(s) {
+			self.recvExtendedHeader(s);
+		});
+	}
+	else {
+		this.secFlag = ((version >> 6) & 0x3);
+		var length = new type.UInt8().read(s).value;
+		if (length & 0x80) {
+			this.transport.expect(1);
+			this.transport.once('data', function(s) {
+				self.recvExtendedFastPathHeader(s, length);
+			});
+		}
+		else {
+			this.transport.expect(length - 2);
+			this.transport.once('data', function(s) {
+				self.recvFastPath(s);
+			});
+		}
+	}
+};
+
+/**
+ * Receive second part of header packet
+ * @param s {type.Stream}
+ */
+TPKT.prototype.recvExtendedHeader = function (s) {
+	var size = new type.UInt16Be().read(s);
+	this.transport.expect(size.value - 4);
+	//next state receive packet
+	var self = this;
+	this.transport.once('data', function(s) {
+		self.recvData(s);
+	});
+};
+
+/**
+ * Receive data available for presentation layer
+ * @param s {type.Stream}
+ */
+TPKT.prototype.recvData = function (s) {
+	this.emit('data', s);
+	this.transport.expect(2);
+	//next state receive header
+	var self = this;
+	this.transport.once('data', function(s) {
+		self.recvHeader(s);
+	});
+};
+
+/**
+ * Read extended fastpath header
+ * @param s {type.Stream}
+ */
+TPKT.prototype.recvExtendedFastPathHeader = function (s, length) {
+	var rightPart = new type.UInt8().read(s).value;
+	var leftPart = length & ~0x80;
+	var packetSize = (leftPart << 8) + rightPart;
+
+	var self = this;
+	this.transport.expect(packetSize - 3);
+	this.transport.once('data', function(s) {
+		self.recvFastPath(s);
+	});
+};
+
+/**
+ * Read fast path data
+ * @param s {type.Stream}
+ */
+TPKT.prototype.recvFastPath = function (s) {
+	this.emit('fastPathData', this.secFlag, s);
+	var self = this;
+	this.transport.expect(2);
+	this.transport.once('data', function(s) {
+		self.recvHeader(s);
+	});
+};
+
+/**
+ * Send message throught TPKT layer
+ * @param message {type.*}
+ */
+TPKT.prototype.send = function(message) {
+	this.transport.send(new type.Component([
+	    new type.UInt8(Action.FASTPATH_ACTION_X224),
+	    new type.UInt8(0),
+	    new type.UInt16Be(message.size() + 4),
+	    message
+	]));
+};
+
+/**
+ * close stack
+ */
+TPKT.prototype.close = function() {
+	this.transport.close();
+};
+
+/**
+ * Module exports
+ */
+module.exports = TPKT;
+