MeshCentral/rdp/protocol/t125/mcs.js

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/*
* 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 events = require('events');
var type = require('../../core').type;
var log = require('../../core').log;
var error = require('../../core').error;
var gcc = require('./gcc');
var per = require('./per');
var asn1 = require('../../asn1');
var cliprdr = require('../pdu/cliprdr');
var Message = {
MCS_TYPE_CONNECT_INITIAL : 0x65,
MCS_TYPE_CONNECT_RESPONSE : 0x66
};
var DomainMCSPDU = {
ERECT_DOMAIN_REQUEST : 1,
DISCONNECT_PROVIDER_ULTIMATUM : 8,
ATTACH_USER_REQUEST : 10,
ATTACH_USER_CONFIRM : 11,
CHANNEL_JOIN_REQUEST : 14,
CHANNEL_JOIN_CONFIRM : 15,
SEND_DATA_REQUEST : 25,
SEND_DATA_INDICATION : 26
};
var Channel = {
MCS_GLOBAL_CHANNEL: 1003,
MCS_USERCHANNEL_BASE: 1001,
MCS_CLIPRDR_CHANNEL: 1005
};
/**
* Channel Definde
*/
const RdpdrChannelDef = new type.Component({
name: new type.BinaryString(Buffer.from('rdpdr' + '\x00\x00\x00', 'binary'), { readLength: new type.CallableValue(8) }),
options: new type.UInt32Le(0x80800000)
});
const RdpsndChannelDef = new type.Component({
name: new type.BinaryString(Buffer.from('rdpsnd' + '\x00\x00', 'binary'), { readLength: new type.CallableValue(8) }),
options: new type.UInt32Le(0xc0000000)
});
const CliprdrChannelDef = new type.Component({
name: new type.BinaryString(Buffer.from('cliprdr' + '\x00', 'binary'), { readLength: new type.CallableValue(8) }),
// CHANNEL_OPTION_INITIALIZED |
// CHANNEL_OPTION_ENCRYPT_RDP |
// CHANNEL_OPTION_COMPRESS_RDP |
// CHANNEL_OPTION_SHOW_PROTOCOL
options: new type.UInt32Le(0xc0a00000)
});
/**
* @see http://www.itu.int/rec/T-REC-T.125-199802-I/en page 25
* @returns {asn1.univ.Sequence}
*/
function DomainParameters(maxChannelIds, maxUserIds, maxTokenIds,
numPriorities, minThoughput, maxHeight, maxMCSPDUsize, protocolVersion) {
return new asn1.univ.Sequence({
maxChannelIds : new asn1.univ.Integer(maxChannelIds),
maxUserIds : new asn1.univ.Integer(maxUserIds),
maxTokenIds : new asn1.univ.Integer(maxTokenIds),
numPriorities : new asn1.univ.Integer(numPriorities),
minThoughput : new asn1.univ.Integer(minThoughput),
maxHeight : new asn1.univ.Integer(maxHeight),
maxMCSPDUsize : new asn1.univ.Integer(maxMCSPDUsize),
protocolVersion : new asn1.univ.Integer(protocolVersion)
});
}
/**
* @see http://www.itu.int/rec/T-REC-T.125-199802-I/en page 25
* @param userData {Buffer}
* @returns {asn1.univ.Sequence}
*/
function ConnectInitial (userData) {
return new asn1.univ.Sequence({
callingDomainSelector : new asn1.univ.OctetString(Buffer.from('\x01', 'binary')),
calledDomainSelector : new asn1.univ.OctetString(Buffer.from('\x01', 'binary')),
upwardFlag : new asn1.univ.Boolean(true),
targetParameters : DomainParameters(34, 2, 0, 1, 0, 1, 0xffff, 2),
minimumParameters : DomainParameters(1, 1, 1, 1, 0, 1, 0x420, 2),
maximumParameters : DomainParameters(0xffff, 0xfc17, 0xffff, 1, 0, 1, 0xffff, 2),
userData : new asn1.univ.OctetString(userData)
}).implicitTag(new asn1.spec.Asn1Tag(asn1.spec.TagClass.Application, asn1.spec.TagFormat.Constructed, 101));
}
/**
* @see http://www.itu.int/rec/T-REC-T.125-199802-I/en page 25
* @returns {asn1.univ.Sequence}
*/
function ConnectResponse (userData) {
return new asn1.univ.Sequence({
result : new asn1.univ.Enumerate(0),
calledConnectId : new asn1.univ.Integer(0),
domainParameters : DomainParameters(22, 3, 0, 1, 0, 1,0xfff8, 2),
userData : new asn1.univ.OctetString(userData)
}).implicitTag(new asn1.spec.Asn1Tag(asn1.spec.TagClass.Application, asn1.spec.TagFormat.Constructed, 102));
}
/**
* Format MCS PDU header packet
* @param mcsPdu {integer}
* @param options {integer}
* @returns {type.UInt8} headers
*/
function writeMCSPDUHeader(mcsPdu, options) {
options = options || 0;
return new type.UInt8((mcsPdu << 2) | options);
}
/**
* Read MCS PDU header
* @param opcode
* @param mcsPdu
* @returns {Boolean}
*/
function readMCSPDUHeader(opcode, mcsPdu) {
return (opcode >> 2) === mcsPdu;
}
/**
* Multi-Channel Services
* @param transport {events.EventEmitter} transport layer listen (connect, data) events
* @param recvOpCode {DomainMCSPDU} opcode use in receive automata
* @param sendOpCode {DomainMCSPDU} opcode use to send message
*/
function MCS(transport, recvOpCode, sendOpCode) {
this.transport = transport;
this.recvOpCode = recvOpCode;
this.sendOpCode = sendOpCode;
this.channels = [
{ id: Channel.MCS_GLOBAL_CHANNEL, name: 'global' },
{ id: Channel.MCS_CLIPRDR_CHANNEL, name: 'cliprdr' }
];
this.channels.find = function(callback) {
for(var i in this) {
if(callback(this[i])) return this[i];
};
};
// bind events
var self = this;
this.transport.on('close', function () {
self.emit('close');
}).on('error', function (err) {
self.emit('error', err);
});
}
//inherit from Layer
inherits(MCS, events.EventEmitter);
/**
* Send message to a specific channel
* @param channelName {string} name of channel
* @param data {type.*} message to send
*/
MCS.prototype.send = function(channelName, data) {
var channelId = this.channels.find(function(element) {
if (element.name === channelName) return true;
}).id;
this.transport.send(new type.Component([
writeMCSPDUHeader(this.sendOpCode),
per.writeInteger16(this.userId, Channel.MCS_USERCHANNEL_BASE),
per.writeInteger16(channelId),
new type.UInt8(0x70),
per.writeLength(data.size()),
data
]));
};
/**
* Main receive function
* @param s {type.Stream}
*/
MCS.prototype.recv = function(s) {
opcode = new type.UInt8().read(s).value;
if (readMCSPDUHeader(opcode, DomainMCSPDU.DISCONNECT_PROVIDER_ULTIMATUM)) {
log.info("MCS DISCONNECT_PROVIDER_ULTIMATUM");
this.transport.close();
return
}
else if(!readMCSPDUHeader(opcode, this.recvOpCode)) {
throw new error.UnexpectedFatalError('NODE_RDP_PROTOCOL_T125_MCS_BAD_RECEIVE_OPCODE');
}
per.readInteger16(s, Channel.MCS_USERCHANNEL_BASE);
var channelId = per.readInteger16(s);
per.readEnumerates(s);
per.readLength(s);
var channelName = this.channels.find(function(e) {
if (e.id === channelId) return true;
}).name;
this.emit(channelName, s);
};
/**
* Only main channels handle actually
* @param transport {event.EventEmitter} bind connect and data events
* @returns
*/
function Client(transport) {
MCS.call(this, transport, DomainMCSPDU.SEND_DATA_INDICATION, DomainMCSPDU.SEND_DATA_REQUEST);
// channel context automata
this.channelsConnected = 0;
// init gcc information
this.clientCoreData = gcc.clientCoreData();
// cliprdr channel
this.clientNetworkData = gcc.clientNetworkData(new type.Component([RdpdrChannelDef, CliprdrChannelDef, RdpsndChannelDef]));
this.clientSecurityData = gcc.clientSecurityData();
// must be readed from protocol
this.serverCoreData = null;
this.serverSecurityData = null;
this.serverNetworkData = null;
var self = this;
this.transport.on('connect', function(s) {
self.connect(s);
});
}
inherits(Client, MCS);
/**
* Connect event layer
*/
Client.prototype.connect = function(selectedProtocol) {
this.clientCoreData.obj.serverSelectedProtocol.value = selectedProtocol;
this.sendConnectInitial();
};
/**
* close stack
*/
Client.prototype.close = function() {
this.transport.close();
};
/**
* MCS connect response (server->client)
* @param s {type.Stream}
*/
Client.prototype.recvConnectResponse = function(s) {
var userData = new type.Stream(ConnectResponse().decode(s, asn1.ber).value.userData.value);
var serverSettings = gcc.readConferenceCreateResponse(userData);
// record server gcc block
for(var i in serverSettings) {
if(!serverSettings[i].obj) {
continue;
}
switch(serverSettings[i].obj.__TYPE__) {
case gcc.MessageType.SC_CORE:
this.serverCoreData = serverSettings[i];
break;
case gcc.MessageType.SC_SECURITY:
this.serverSecurityData = serverSettings[i];
break;
case gcc.MessageType.SC_NET:
this.serverNetworkData = serverSettings[i];
break;
default:
log.warn('unhandle server gcc block : ' + serverSettings[i].obj.__TYPE__);
}
}
// send domain request
this.sendErectDomainRequest();
// send attach user request
this.sendAttachUserRequest();
// now wait user confirm from server
var self = this;
this.transport.once('data', function(s) {
self.recvAttachUserConfirm(s);
});
};
/**
* MCS connection automata step
* @param s {type.Stream}
*/
Client.prototype.recvAttachUserConfirm = function(s) {
if (!readMCSPDUHeader(new type.UInt8().read(s).value, DomainMCSPDU.ATTACH_USER_CONFIRM)) {
throw new error.UnexpectedFatalError('NODE_RDP_PROTOCOL_T125_MCS_BAD_HEADER');
}
if (per.readEnumerates(s) !== 0) {
throw new error.UnexpectedFatalError('NODE_RDP_PROTOCOL_T125_MCS_SERVER_REJECT_USER');
}
this.userId = per.readInteger16(s, Channel.MCS_USERCHANNEL_BASE);
//ask channel for specific user
this.channels.push({ id : this.userId, name : 'user' });
// channel connect automata
this.connectChannels();
};
/**
* Last state in channel connection automata
* @param s {type.Stream}
*/
Client.prototype.recvChannelJoinConfirm = function(s) {
var opcode = new type.UInt8().read(s).value;
if (!readMCSPDUHeader(opcode, DomainMCSPDU.CHANNEL_JOIN_CONFIRM)) {
throw new error.UnexpectedFatalError('NODE_RDP_PROTOCOL_T125_MCS_WAIT_CHANNEL_JOIN_CONFIRM');
}
var confirm = per.readEnumerates(s);
var userId = per.readInteger16(s, Channel.MCS_USERCHANNEL_BASE);
if (this.userId !== userId) {
throw new error.UnexpectedFatalError('NODE_RDP_PROTOCOL_T125_MCS_INVALID_USER_ID');
}
var channelId = per.readInteger16(s);
//if ((confirm !== 0) && (channelId === Channel.MCS_GLOBAL_CHANNEL || channelId === this.userId)) {
if ((confirm !== 0) && (channelId === Channel.MCS_CLIPRDR_CHANNEL || channelId === Channel.MCS_GLOBAL_CHANNEL || channelId === this.userId)) {
throw new error.UnexpectedFatalError('NODE_RDP_PROTOCOL_T125_MCS_SERVER_MUST_CONFIRM_STATIC_CHANNEL');
}
this.connectChannels();
};
/**
* First MCS message
*/
Client.prototype.sendConnectInitial = function() {
var ccReq = gcc.writeConferenceCreateRequest(new type.Component([
gcc.block(this.clientCoreData),
gcc.block(this.clientNetworkData),
gcc.block(this.clientSecurityData)
])).toStream().getValue();
this.transport.send(ConnectInitial(ccReq).encode(asn1.ber));
// next event is connect response
var self = this;
this.transport.once('data', function(s) {
self.recvConnectResponse(s);
});
};
/**
* MCS connection automata step
*/
Client.prototype.sendErectDomainRequest = function() {
this.transport.send(new type.Component([
writeMCSPDUHeader(DomainMCSPDU.ERECT_DOMAIN_REQUEST),
per.writeInteger(0),
per.writeInteger(0)
]));
};
/**
* MCS connection automata step
*/
Client.prototype.sendAttachUserRequest = function() {
this.transport.send(writeMCSPDUHeader(DomainMCSPDU.ATTACH_USER_REQUEST));
};
/**
* Send a channel join request
* @param channelId {integer} channel id
*/
Client.prototype.sendChannelJoinRequest = function(channelId) {
this.transport.send(new type.Component([
writeMCSPDUHeader(DomainMCSPDU.CHANNEL_JOIN_REQUEST),
per.writeInteger16(this.userId, Channel.MCS_USERCHANNEL_BASE),
per.writeInteger16(channelId)
]));
};
/**
* Connect channels automata
* @param s {type.Stream}
*/
Client.prototype.connectChannels = function(s) {
if(this.channelsConnected == this.channels.length) {
var self = this;
this.transport.on('data', function(s) {
self.recv(s);
});
// send client and sever gcc informations
this.emit('connect',
{
core : this.clientCoreData.obj,
security : this.clientSecurityData.obj,
net : this.clientNetworkData.obj
},
{
core : this.serverCoreData.obj,
security : this.serverSecurityData.obj
}, this.userId, this.channels);
return;
}
this.sendChannelJoinRequest(this.channels[this.channelsConnected++].id);
var self = this;
this.transport.once('data', function(s) {
self.recvChannelJoinConfirm(s);
});
};
/**
* Server side of MCS layer
* @param transport
*/
function Server (transport) {
MCS.call(this, transport, DomainMCSPDU.SEND_DATA_REQUEST, DomainMCSPDU.SEND_DATA_INDICATION);
// must be readed from protocol
this.clientCoreData = null;
this.clientNetworkData = null;
this.clientSecurityData = null;
// init gcc information
this.serverCoreData = gcc.serverCoreData();
this.serverSecurityData = gcc.serverSecurityData();
this.serverNetworkData = gcc.serverNetworkData(new type.Component([]));
var self = this;
this.transport.on('connect', function (selectedProtocol) {
self.serverCoreData.obj.clientRequestedProtocol.value = selectedProtocol;
}).once('data', function (s) {
self.recvConnectInitial(s);
});
}
inherits(Server, MCS);
/**
* First state of server automata
* @param s {type.Stream}
*/
Server.prototype.recvConnectInitial = function (s) {
var userData = new type.Stream(ConnectInitial().decode(s, asn1.ber).value.userData.value);
var clientSettings = gcc.readConferenceCreateRequest(userData);
// record server gcc block
for(var i in clientSettings) {
if(!clientSettings[i].obj) {
continue;
}
switch(clientSettings[i].obj.__TYPE__) {
case gcc.MessageType.CS_CORE:
this.clientCoreData = clientSettings[i];
break;
case gcc.MessageType.CS_SECURITY:
this.clientSecurityData = clientSettings[i];
break;
case gcc.MessageType.CS_NET:
this.clientNetworkData = clientSettings[i];
for (var i = 0; i < this.clientNetworkData.obj.channelCount.value; i++) {
this.serverNetworkData.obj.channelIdArray.obj.push(new type.UInt16Le( i + 1 + Channel.MCS_GLOBAL_CHANNEL));
}
break;
default:
log.debug('unhandle client gcc block : ' + clientSettings[i].obj.__TYPE__);
}
}
this.sendConnectResponse();
};
/**
* State 2 in mcs server connetion automata
*/
Server.prototype.sendConnectResponse = function () {
var ccReq = gcc.writeConferenceCreateResponse(new type.Component([
gcc.block(this.serverCoreData),
gcc.block(this.serverSecurityData),
gcc.block(this.serverNetworkData),
])).toStream().getValue();
this.transport.send(ConnectResponse(ccReq).encode(asn1.ber));
};
/**
* Module exports
*/
module.exports = {
Client : Client,
Server : Server
};