/**
* @description MeshCentral connection relay module
* @author Ylian Saint-Hilaire
* @copyright Intel Corporation 2018-2019
* @license Apache-2.0
* @version v0.0.1
*/
/*jslint node: true */
/*jshint node: true */
/*jshint strict:false */
/*jshint -W097 */
/*jshint esversion: 6 */
"use strict";
module.exports.CreateMeshRelay = function (parent, ws, req, domain, user, cookie) {
var obj = {};
obj.ws = ws;
obj.id = req.query.id;
obj.user = user;
obj.ruserid = null;
obj.req = req; // Used in multi-server.js
// Check relay authentication
if ((user == null) && (req.query.rauth != null)) {
const rcookie = parent.parent.decodeCookie(req.query.rauth, parent.parent.loginCookieEncryptionKey, 240); // Cookie with 4 hour timeout
if (rcookie.ruserid != null) { obj.ruserid = rcookie.ruserid; }
}
// If there is no authentication, drop this connection
if ((obj.id != null) && (obj.id.startsWith('meshmessenger/') == false) && (obj.user == null) && (obj.ruserid == null)) { try { ws.close(); parent.parent.debug('relay', 'Relay: Connection with no authentication (' + cleanRemoteAddr(req.ip) + ')'); } catch (e) { console.log(e); } return; }
// Relay session count (we may remove this in the future)
obj.relaySessionCounted = true;
parent.relaySessionCount++;
// Mesh Rights
const MESHRIGHT_EDITMESH = 1;
const MESHRIGHT_MANAGEUSERS = 2;
const MESHRIGHT_MANAGECOMPUTERS = 4;
const MESHRIGHT_REMOTECONTROL = 8;
const MESHRIGHT_AGENTCONSOLE = 16;
const MESHRIGHT_SERVERFILES = 32;
const MESHRIGHT_WAKEDEVICE = 64;
const MESHRIGHT_SETNOTES = 128;
const MESHRIGHT_REMOTEVIEW = 256;
// Site rights
const SITERIGHT_SERVERBACKUP = 1;
const SITERIGHT_MANAGEUSERS = 2;
const SITERIGHT_SERVERRESTORE = 4;
const SITERIGHT_FILEACCESS = 8;
const SITERIGHT_SERVERUPDATE = 16;
const SITERIGHT_LOCKED = 32;
// Clean a IPv6 address that encodes a IPv4 address
function cleanRemoteAddr(addr) { if (addr.startsWith('::ffff:')) { return addr.substring(7); } else { return addr; } }
// Disconnect this agent
obj.close = function (arg) {
if ((arg == 1) || (arg == null)) { try { ws.close(); parent.parent.debug('relay', 'Relay: Soft disconnect (' + cleanRemoteAddr(req.ip) + ')'); } catch (e) { console.log(e); } } // Soft close, close the websocket
if (arg == 2) { try { ws._socket._parent.end(); parent.parent.debug('relay', 'Relay: Hard disconnect (' + cleanRemoteAddr(req.ip) + ')'); } catch (e) { console.log(e); } } // Hard close, close the TCP socket
// Aggressive cleanup
delete obj.id;
delete obj.ws;
delete obj.peer;
};
obj.sendAgentMessage = function (command, userid, domainid) {
var rights, mesh;
if (command.nodeid == null) return false;
var user = parent.users[userid];
if (user == null) return false;
var splitnodeid = command.nodeid.split('/');
// Check that we are in the same domain and the user has rights over this node.
if ((splitnodeid[0] == 'node') && (splitnodeid[1] == domainid)) {
// Get the user object
// See if the node is connected
var agent = parent.wsagents[command.nodeid];
if (agent != null) {
// Check if we have permission to send a message to that node
rights = user.links[agent.dbMeshKey];
mesh = parent.meshes[agent.dbMeshKey];
if ((rights != null) && (mesh != null) || ((rights & 16) != 0)) { // TODO: 16 is console permission, may need more gradular permission checking
if (ws.sessionId) { command.sessionid = ws.sessionId; } // Set the session id, required for responses.
command.rights = rights.rights; // Add user rights flags to the message
command.consent = mesh.consent; // Add user consent
if (typeof domain.userconsentflags == 'number') { command.consent |= domain.userconsentflags; } // Add server required consent flags
command.username = user.name; // Add user name
delete command.nodeid; // Remove the nodeid since it's implyed.
agent.send(JSON.stringify(command));
return true;
}
} else {
// Check if a peer server is connected to this agent
var routing = parent.parent.GetRoutingServerId(command.nodeid, 1); // 1 = MeshAgent routing type
if (routing != null) {
// Check if we have permission to send a message to that node
rights = user.links[routing.meshid];
mesh = parent.meshes[routing.meshid];
if (rights != null || ((rights & 16) != 0)) { // TODO: 16 is console permission, may need more gradular permission checking
if (ws.sessionId) { command.fromSessionid = ws.sessionId; } // Set the session id, required for responses.
command.rights = rights.rights; // Add user rights flags to the message
command.consent = mesh.consent; // Add user consent
if (typeof domain.userconsentflags == 'number') { command.consent |= domain.userconsentflags; } // Add server required consent flags
command.username = user.name; // Add user name
parent.parent.multiServer.DispatchMessageSingleServer(command, routing.serverid);
return true;
}
}
}
}
return false;
};
function performRelay() {
if (obj.id == null) { try { obj.close(); } catch (e) { } return null; } // Attempt to connect without id, drop this.
ws._socket.setKeepAlive(true, 240000); // Set TCP keep alive
// If this is a MeshMessenger session, the ID is the two userid's and authentication must match one of them.
if (obj.id.startsWith('meshmessenger/')) {
if ((obj.id.startsWith('meshmessenger/user/') == true) && (user == null)) { try { obj.close(); } catch (e) { } return null; } // If user-to-user, both sides need to be authenticated.
var x = obj.id.split('/'), user1 = x[1] + '/' + x[2] + '/' + x[3], user2 = x[4] + '/' + x[5] + '/' + x[6];
if ((x[1] != 'user') && (x[4] != 'user')) { try { obj.close(); } catch (e) { } return null; } // MeshMessenger session must have at least one authenticated user
if ((x[1] == 'user') && (x[4] == 'user')) {
// If this is a user-to-user session, you must be authenticated to join.
if ((user._id != user1) && (user._id != user2)) { try { obj.close(); } catch (e) { } return null; }
} else {
// If only one side of the session is a user
// !!!!! TODO: Need to make sure that one of the two sides is the correct user. !!!!!
}
}
// Validate that the id is valid, we only need to do this on non-authenticated sessions.
// TODO: Figure out when this needs to be done.
/*
if (!parent.args.notls) {
// Check the identifier, if running without TLS, skip this.
var ids = obj.id.split(':');
if (ids.length != 3) { ws.close(); delete obj.id; return null; } // Invalid ID, drop this.
if (parent.crypto.createHmac('SHA384', parent.relayRandom).update(ids[0] + ':' + ids[1]).digest('hex') != ids[2]) { ws.close(); delete obj.id; return null; } // Invalid HMAC, drop this.
if ((Date.now() - parseInt(ids[1])) > 120000) { ws.close(); delete obj.id; return null; } // Expired time, drop this.
obj.id = ids[0];
}
*/
// Check the peer connection status
{
var relayinfo = parent.wsrelays[obj.id];
if (relayinfo) {
if (relayinfo.state == 1) {
// Check that at least one connection is authenticated
if ((obj.authenticated != true) && (relayinfo.peer1.authenticated != true)) {
ws.close();
parent.parent.debug('relay', 'Relay without-auth: ' + obj.id + ' (' + cleanRemoteAddr(req.ip) + ')');
delete obj.id;
delete obj.ws;
delete obj.peer;
return null;
}
// Check that both connection are for the same user
if (!obj.id.startsWith('meshmessenger/')) {
var u1 = obj.user ? obj.user._id : obj.ruserid;
var u2 = relayinfo.peer1.user ? relayinfo.peer1.user._id : relayinfo.peer1.ruserid;
if (parent.args.user != null) { // If the server is setup with a default user, correct the userid now.
if (u1 != null) { u1 = 'user/' + domain.id + '/' + parent.args.user.toLowerCase(); }
if (u2 != null) { u2 = 'user/' + domain.id + '/' + parent.args.user.toLowerCase(); }
}
if (u1 != u2) {
ws.close();
parent.parent.debug('relay', 'Relay auth mismatch (' + u1 + ' != ' + u2 + '): ' + obj.id + ' (' + cleanRemoteAddr(req.ip) + ')');
delete obj.id;
delete obj.ws;
delete obj.peer;
return null;
}
}
// Connect to peer
obj.peer = relayinfo.peer1;
obj.peer.peer = obj;
relayinfo.peer2 = obj;
relayinfo.state = 2;
relayinfo.peer1.ws._socket.resume(); // Release the traffic
relayinfo.peer2.ws._socket.resume(); // Release the traffic
ws.time = relayinfo.peer1.ws.time = Date.now();
relayinfo.peer1.ws.peer = relayinfo.peer2.ws;
relayinfo.peer2.ws.peer = relayinfo.peer1.ws;
// Remove the timeout
if (relayinfo.timeout) { clearTimeout(relayinfo.timeout); delete relayinfo.timeout; }
// Setup session recording
var sessionUser = obj.user;
if (sessionUser == null) { sessionUser = obj.peer.user; }
if ((sessionUser != null) && (domain.sessionrecording == true || ((typeof domain.sessionrecording == 'object') && ((domain.sessionrecording.protocols == null) || (domain.sessionrecording.protocols.indexOf(parseInt(req.query.p)) >= 0))))) {
// Get the computer name
parent.db.Get(req.query.nodeid, function (err, nodes) {
var xusername = '', xdevicename = '', xdevicename2 = null;
if ((nodes != null) && (nodes.length == 1)) { xdevicename2 = nodes[0].name; xdevicename = '-' + parent.common.makeFilename(nodes[0].name); }
// Get the username and make it acceptable as a filename
if (sessionUser._id) { xusername = '-' + parent.common.makeFilename(sessionUser._id.split('/')[2]); }
var now = new Date(Date.now());
var recFilename = 'relaysession' + ((domain.id == '') ? '' : '-') + domain.id + '-' + now.getUTCFullYear() + '-' + parent.common.zeroPad(now.getUTCMonth(), 2) + '-' + parent.common.zeroPad(now.getUTCDate(), 2) + '-' + parent.common.zeroPad(now.getUTCHours(), 2) + '-' + parent.common.zeroPad(now.getUTCMinutes(), 2) + '-' + parent.common.zeroPad(now.getUTCSeconds(), 2) + xusername + xdevicename + '-' + obj.id + '.mcrec'
var recFullFilename = null;
if (domain.sessionrecording.filepath) {
try { parent.parent.fs.mkdirSync(domain.sessionrecording.filepath); } catch (e) { }
recFullFilename = parent.parent.path.join(domain.sessionrecording.filepath, recFilename);
} else {
try { parent.parent.fs.mkdirSync(parent.parent.recordpath); } catch (e) { }
recFullFilename = parent.parent.path.join(parent.parent.recordpath, recFilename);
}
parent.parent.fs.open(recFullFilename, 'w', function (err, fd) {
if (err != null) {
// Unable to record
try { ws.send('c'); } catch (ex) { } // Send connect to both peers
try { relayinfo.peer1.ws.send('c'); } catch (ex) { }
} else {
// Write the recording file header
var metadata = { magic: 'MeshCentralRelaySession', ver: 1, userid: sessionUser._id, username: sessionUser.name, sessionid: obj.id, ipaddr1: cleanRemoteAddr(req.ip), ipaddr2: cleanRemoteAddr(obj.peer.req.ip), time: new Date().toLocaleString(), protocol: req.query.p, nodeid: req.query.nodeid };
if (xdevicename2 != null) { metadata.devicename = xdevicename2; }
var firstBlock = JSON.stringify(metadata);
recordingEntry(fd, 1, ((req.query.browser) ? 2 : 0), firstBlock, function () {
try { relayinfo.peer1.ws.logfile = ws.logfile = { fd: fd, lock: false }; } catch (ex) {
try { ws.send('c'); } catch (ex) { } // Send connect to both peers, 'cr' indicates the session is being recorded.
try { relayinfo.peer1.ws.send('c'); } catch (ex) { }
return;
}
try { ws.send('cr'); } catch (ex) { } // Send connect to both peers, 'cr' indicates the session is being recorded.
try { relayinfo.peer1.ws.send('cr'); } catch (ex) { }
});
}
});
});
} else {
// Send session start
try { ws.send('c'); } catch (ex) { } // Send connect to both peers
try { relayinfo.peer1.ws.send('c'); } catch (ex) { }
}
parent.parent.debug('relay', 'Relay connected: ' + obj.id + ' (' + cleanRemoteAddr(req.ip) + ' --> ' + cleanRemoteAddr(obj.peer.req.ip) + ')');
// Log the connection
if (sessionUser != null) {
var msg = 'Started relay session';
if (req.query.p == 1) { msg = 'Started terminal session'; }
else if (req.query.p == 2) { msg = 'Started desktop session'; }
else if (req.query.p == 5) { msg = 'Started file management session'; }
var event = { etype: 'relay', action: 'relaylog', domain: domain.id, userid: sessionUser._id, username: sessionUser.name, msg: msg + ' \"' + obj.id + '\" from ' + cleanRemoteAddr(obj.peer.req.ip) + ' to ' + cleanRemoteAddr(req.ip), protocol: req.query.p, nodeid: req.query.nodeid };
parent.parent.DispatchEvent(['*', sessionUser._id], obj, event);
}
} else {
// Connected already, drop (TODO: maybe we should re-connect?)
ws.close();
parent.parent.debug('relay', 'Relay duplicate: ' + obj.id + ' (' + cleanRemoteAddr(req.ip) + ')');
delete obj.id;
delete obj.ws;
delete obj.peer;
return null;
}
} else {
// Wait for other relay connection
ws._socket.pause(); // Hold traffic until the other connection
parent.wsrelays[obj.id] = { peer1: obj, state: 1, timeout: setTimeout(function () { closeBothSides(); }, 30000) };
parent.parent.debug('relay', 'Relay holding: ' + obj.id + ' (' + cleanRemoteAddr(req.ip) + ') ' + (obj.authenticated ? 'Authenticated' : ''));
// Check if a peer server has this connection
if (parent.parent.multiServer != null) {
var rsession = parent.wsPeerRelays[obj.id];
if ((rsession != null) && (rsession.serverId > parent.parent.serverId)) {
// We must initiate the connection to the peer
parent.parent.multiServer.createPeerRelay(ws, req, rsession.serverId, req.session.userid);
delete parent.wsrelays[obj.id];
} else {
// Send message to other peers that we have this connection
parent.parent.multiServer.DispatchMessage(JSON.stringify({ action: 'relay', id: obj.id }));
}
}
}
}
}
ws.flushSink = function () { try { ws._socket.resume(); } catch (ex) { console.log(ex); } };
// When data is received from the mesh relay web socket
ws.on('message', function (data) {
//console.log(typeof data, data.length);
if (this.peer != null) {
//if (typeof data == 'string') { console.log('Relay: ' + data); } else { console.log('Relay:' + data.length + ' byte(s)'); }
try {
this._socket.pause();
if (this.logfile != null) {
// Write data to log file then perform relay
var xthis = this;
recordingEntry(this.logfile.fd, 2, ((req.query.browser) ? 2 : 0), data, function () { xthis.peer.send(data, ws.flushSink); });
} else {
// Perform relay
this.peer.send(data, ws.flushSink);
}
} catch (ex) { console.log(ex); }
}
});
// If error, close both sides of the relay.
ws.on('error', function (err) {
parent.relaySessionErrorCount++;
if (obj.relaySessionCounted) { parent.relaySessionCount--; delete obj.relaySessionCounted; }
console.log('Relay error from ' + cleanRemoteAddr(req.ip) + ', ' + err.toString().split('\r')[0] + '.');
closeBothSides();
});
// If the relay web socket is closed, close both sides.
ws.on('close', function (req) {
if (obj.relaySessionCounted) { parent.relaySessionCount--; delete obj.relaySessionCounted; }
closeBothSides();
});
// Close both our side and the peer side.
function closeBothSides() {
if (obj.id != null) {
var relayinfo = parent.wsrelays[obj.id];
if (relayinfo != null) {
if (relayinfo.state == 2) {
var peer = (relayinfo.peer1 == obj) ? relayinfo.peer2 : relayinfo.peer1;
// Close the recording file
if (ws.logfile != null) { recordingEntry(ws.logfile.fd, 3, 0, 'MeshCentralMCREC', function (fd, tag) { parent.parent.fs.close(fd); tag.ws.logfile = null; tag.pws.logfile = null; }, { ws: ws, pws: peer.ws }); }
// Disconnect the peer
try { if (peer.relaySessionCounted) { parent.relaySessionCount--; delete peer.relaySessionCounted; } } catch (ex) { console.log(ex); }
parent.parent.debug('relay', 'Relay disconnect: ' + obj.id + ' (' + cleanRemoteAddr(req.ip) + ' --> ' + cleanRemoteAddr(peer.req.ip) + ')');
try { peer.ws.close(); } catch (e) { } // Soft disconnect
try { peer.ws._socket._parent.end(); } catch (e) { } // Hard disconnect
// Log the disconnection
if (ws.time) {
var msg = 'Ended relay session';
if (req.query.p == 1) { msg = 'Ended terminal session'; }
else if (req.query.p == 2) { msg = 'Ended desktop session'; }
else if (req.query.p == 5) { msg = 'Ended file management session'; }
if (user) {
var event = { etype: 'relay', action: 'relaylog', domain: domain.id, userid: user._id, username: parent.users[user._id].name, msg: msg + ' \"' + obj.id + '\" from ' + cleanRemoteAddr(obj.peer.req.ip) + ' to ' + cleanRemoteAddr(req.ip) + ', ' + Math.floor((Date.now() - ws.time) / 1000) + ' second(s)', protocol: req.query.p, nodeid: req.query.nodeid };
parent.parent.DispatchEvent(['*', user._id], obj, event);
} else if (peer.user) {
var event = { etype: 'relay', action: 'relaylog', domain: domain.id, userid: peer.user._id, username: parent.users[peer.user._id].name, msg: msg + ' \"' + obj.id + '\" from ' + cleanRemoteAddr(obj.peer.req.ip) + ' to ' + cleanRemoteAddr(req.ip) + ', ' + Math.floor((Date.now() - ws.time) / 1000) + ' second(s)', protocol: req.query.p, nodeid: req.query.nodeid };
parent.parent.DispatchEvent(['*', peer.user._id], obj, event);
}
}
// Aggressive peer cleanup
delete peer.id;
delete peer.ws;
delete peer.peer;
} else {
parent.parent.debug('relay', 'Relay disconnect: ' + obj.id + ' (' + cleanRemoteAddr(req.ip) + ')');
}
try { ws.close(); } catch (ex) { }
delete parent.wsrelays[obj.id];
}
}
// Aggressive cleanup
delete obj.id;
delete obj.ws;
delete obj.peer;
}
// Record a new entry in a recording log
function recordingEntry(fd, type, flags, data, func, tag) {
try {
if (typeof data == 'string') {
// String write
var blockData = Buffer.from(data), header = Buffer.alloc(16); // Header: Type (2) + Flags (2) + Size(4) + Time(8)
header.writeInt16BE(type, 0); // Type (1 = Header, 2 = Network Data)
header.writeInt16BE(flags, 2); // Flags (1 = Binary, 2 = User)
header.writeInt32BE(blockData.length, 4); // Size
header.writeIntBE(new Date(), 10, 6); // Time
var block = Buffer.concat([header, blockData]);
parent.parent.fs.write(fd, block, 0, block.length, function () { func(fd, tag); });
} else {
// Binary write
var header = Buffer.alloc(16); // Header: Type (2) + Flags (2) + Size(4) + Time(8)
header.writeInt16BE(type, 0); // Type (1 = Header, 2 = Network Data)
header.writeInt16BE(flags | 1, 2); // Flags (1 = Binary, 2 = User)
header.writeInt32BE(data.length, 4); // Size
header.writeIntBE(new Date(), 10, 6); // Time
var block = Buffer.concat([header, data]);
parent.parent.fs.write(fd, block, 0, block.length, function () { func(fd, tag); });
}
} catch (ex) { console.log(ex); func(fd, tag); }
}
// Mark this relay session as authenticated if this is the user end.
obj.authenticated = (user != null);
if (obj.authenticated) {
// Kick off the routing, if we have agent routing instructions, process them here.
// Routing instructions can only be given by a authenticated user
if ((cookie != null) && (cookie.nodeid != null) && (cookie.tcpport != null) && (cookie.domainid != null)) {
// We have routing instructions in the cookie, but first, check user access for this node.
parent.db.Get(cookie.nodeid, function (err, docs) {
if (docs.length == 0) { console.log('ERR: Node not found'); try { obj.close(); } catch (e) { } return; } // Disconnect websocket
const node = docs[0];
// Check if this user has permission to manage this computer
const meshlinks = user.links[node.meshid];
if ((!meshlinks) || (!meshlinks.rights) || ((meshlinks.rights & MESHRIGHT_REMOTECONTROL) == 0)) { console.log('ERR: Access denied (2)'); try { obj.close(); } catch (e) { } return; }
// Send connection request to agent
const rcookie = parent.parent.encodeCookie({ ruserid: user._id }, parent.parent.loginCookieEncryptionKey);
if (obj.id == undefined) { obj.id = ('' + Math.random()).substring(2); } // If there is no connection id, generate one.
const command = { nodeid: cookie.nodeid, action: 'msg', type: 'tunnel', value: '*/meshrelay.ashx?id=' + obj.id + '&rauth=' + rcookie, tcpport: cookie.tcpport, tcpaddr: cookie.tcpaddr };
parent.parent.debug('relay', 'Relay: Sending agent tunnel command: ' + JSON.stringify(command));
if (obj.sendAgentMessage(command, user._id, cookie.domainid) == false) { delete obj.id; parent.parent.debug('relay', 'Relay: Unable to contact this agent (' + cleanRemoteAddr(req.ip) + ')'); }
performRelay();
});
return obj;
} else if ((req.query.nodeid != null) && ((req.query.tcpport != null) || (req.query.udpport != null))) {
// We have routing instructions in the URL arguments, but first, check user access for this node.
parent.db.Get(req.query.nodeid, function (err, docs) {
if (docs.length == 0) { console.log('ERR: Node not found'); try { obj.close(); } catch (e) { } return; } // Disconnect websocket
const node = docs[0];
// Check if this user has permission to manage this computer
const meshlinks = user.links[node.meshid];
if ((!meshlinks) || (!meshlinks.rights) || ((meshlinks.rights & MESHRIGHT_REMOTECONTROL) == 0)) { console.log('ERR: Access denied (2)'); try { obj.close(); } catch (e) { } return; }
// Send connection request to agent
if (obj.id == null) { obj.id = ('' + Math.random()).substring(2); } // If there is no connection id, generate one.
const rcookie = parent.parent.encodeCookie({ ruserid: user._id }, parent.parent.loginCookieEncryptionKey);
if (req.query.tcpport != null) {
const command = { nodeid: req.query.nodeid, action: 'msg', type: 'tunnel', value: '*/meshrelay.ashx?id=' + obj.id + '&rauth=' + rcookie, tcpport: req.query.tcpport, tcpaddr: ((req.query.tcpaddr == null) ? '127.0.0.1' : req.query.tcpaddr) };
parent.parent.debug('relay', 'Relay: Sending agent TCP tunnel command: ' + JSON.stringify(command));
if (obj.sendAgentMessage(command, user._id, domain.id) == false) { delete obj.id; parent.parent.debug('relay', 'Relay: Unable to contact this agent (' + cleanRemoteAddr(req.ip) + ')'); }
} else if (req.query.udpport != null) {
const command = { nodeid: req.query.nodeid, action: 'msg', type: 'tunnel', value: '*/meshrelay.ashx?id=' + obj.id + '&rauth=' + rcookie, udpport: req.query.udpport, udpaddr: ((req.query.udpaddr == null) ? '127.0.0.1' : req.query.udpaddr) };
parent.parent.debug('relay', 'Relay: Sending agent UDP tunnel command: ' + JSON.stringify(command));
if (obj.sendAgentMessage(command, user._id, domain.id) == false) { delete obj.id; parent.parent.debug('relay', 'Relay: Unable to contact this agent (' + cleanRemoteAddr(req.ip) + ')'); }
}
performRelay();
});
return obj;
}
}
// If this is not an authenticated session, or the session does not have routing instructions, just go ahead an connect to existing session.
performRelay();
return obj;
};
/*
Relay session recording required that "SessionRecording":true be set in the domain section of the config.json.
Once done, a folder "meshcentral-recordings" will be created next to "meshcentral-data" that will contain all
of the recording files with the .mcrec extension.
The recording files are binary and contain a set of:
<HEADER><DATABLOCK><HEADER><DATABLOCK><HEADER><DATABLOCK><HEADER><DATABLOCK>...
The header is always 16 bytes long and is encoded like this:
TYPE 2 bytes, 1 = Header, 2 = Network Data, 3 = EndBlock
FLAGS 2 bytes, 0x0001 = Binary, 0x0002 = User
SIZE 4 bytes, Size of the data following this header.
TIME 8 bytes, Time this record was written, number of milliseconds since 1 January, 1970 UTC.
All values are BigEndian encoded. The first data block is of TYPE 1 and contains a JSON string with information
about this recording. It looks something like this:
{
magic: 'MeshCentralRelaySession',
ver: 1,
userid: "user\domain\userid",
username: "username",
sessionid: "RandomValue",
ipaddr1: 1.2.3.4,
ipaddr2: 1.2.3.5,
time: new Date().toLocaleString()
}
The rest of the data blocks are all network traffic that was relayed thru the server. They are of TYPE 2 and have
a given size and timestamp. When looking at network traffic the flags are important:
- If traffic has the first (0x0001) flag set, the data is binary otherwise it's a string.
- If the traffic has the second (0x0002) flag set, traffic is coming from the user's browser, if not, it's coming from the MeshAgent.
*/