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cryptpad/NetfluxWebsocketSrv.js

305 lines
11 KiB
JavaScript

;(function () { 'use strict';
const Crypto = require('crypto');
const Nacl = require('tweetnacl');
const LAG_MAX_BEFORE_DISCONNECT = 30000;
const LAG_MAX_BEFORE_PING = 15000;
const HISTORY_KEEPER_ID = Crypto.randomBytes(8).toString('hex');
const USE_HISTORY_KEEPER = true;
const USE_FILE_BACKUP_STORAGE = true;
let dropUser;
let historyKeeperKeys = {};
const now = function () { return (new Date()).getTime(); };
const sendMsg = function (ctx, user, msg) {
try {
if (ctx.config.logToStdout) { console.log('<' + JSON.stringify(msg)); }
user.socket.send(JSON.stringify(msg));
} catch (e) {
console.log(e.stack);
dropUser(ctx, user);
}
};
const storeMessage = function (ctx, channel, msg) {
ctx.store.message(channel.id, msg, function (err) {
if (err && typeof(err) !== 'function') {
// ignore functions because older datastores
// might pass waitFors into the callback
console.log("Error writing message: " + err);
}
});
};
const sendChannelMessage = function (ctx, channel, msgStruct) {
msgStruct.unshift(0);
channel.forEach(function (user) {
if(msgStruct[2] !== 'MSG' || user.id !== msgStruct[1]) { // We don't want to send back a message to its sender, in order to save bandwidth
sendMsg(ctx, user, msgStruct);
}
});
if (USE_HISTORY_KEEPER && msgStruct[2] === 'MSG') {
if (historyKeeperKeys[channel.id]) {
let signedMsg = msgStruct[4].replace(/^cp\|/, '');
signedMsg = Nacl.util.decodeBase64(signedMsg);
let validateKey = Nacl.util.decodeBase64(historyKeeperKeys[channel.id]);
let validated = Nacl.sign.open(signedMsg, validateKey);
if (!validated) {
console.log("Signed message rejected");
return;
}
}
storeMessage(ctx, channel, JSON.stringify(msgStruct));
}
};
dropUser = function (ctx, user) {
if (user.socket.readyState !== 2 /* WebSocket.CLOSING */
&& user.socket.readyState !== 3 /* WebSocket.CLOSED */)
{
try {
user.socket.close();
} catch (e) {
console.log("Failed to disconnect ["+user.id+"], attempting to terminate");
try {
user.socket.terminate();
} catch (ee) {
console.log("Failed to terminate ["+user.id+"] *shrug*");
}
}
}
delete ctx.users[user.id];
Object.keys(ctx.channels).forEach(function (chanName) {
let chan = ctx.channels[chanName];
let idx = chan.indexOf(user);
if (idx < 0) { return; }
if (ctx.verbose) {
console.log("Removing ["+user.id+"] from channel ["+chanName+"]");
}
chan.splice(idx, 1);
if (chan.length === 0) {
if (ctx.verbose) {
console.log("Removing empty channel ["+chanName+"]");
}
delete ctx.channels[chanName];
delete historyKeeperKeys[chanName];
/* Call removeChannel if it is a function and channel removal is
set to true in the config file */
if (ctx.config.removeChannels) {
if (typeof(ctx.store.removeChannel) === 'function') {
ctx.timeouts[chanName] = setTimeout(function () {
ctx.store.removeChannel(chanName, function (err) {
if (err) { console.error("[removeChannelErr]: %s", err); }
else {
if (ctx.verbose) {
console.log("Deleted channel [%s] history from database...", chanName);
}
}
});
}, ctx.config.channelRemovalTimeout);
} else {
console.error("You have configured your server to remove empty channels, " +
"however, the database adaptor you are using has not implemented this behaviour.");
}
}
} else {
sendChannelMessage(ctx, chan, [user.id, 'LEAVE', chanName, 'Quit: [ dropUser() ]']);
}
});
};
const getHistory = function (ctx, channelName, handler, cb) {
var messageBuf = [];
var messageKey;
ctx.store.getMessages(channelName, function (msgStr) {
var parsed = JSON.parse(msgStr);
if (parsed.validateKey) {
historyKeeperKeys[channelName] = parsed.validateKey;
handler(parsed);
return;
}
messageBuf.push(parsed);
}, function (err) {
if (err) {
console.log("Error getting messages " + err.stack);
// TODO: handle this better
}
var startPoint;
var cpCount = 0;
var msgBuff2 = [];
for (startPoint = messageBuf.length - 1; startPoint >= 0; startPoint--) {
var msg = messageBuf[startPoint];
msgBuff2.push(msg);
if (msg[2] === 'MSG' && msg[4].indexOf('cp|') === 0) {
cpCount++;
if (cpCount >= 2) {
for (var x = msgBuff2.pop(); x; x = msgBuff2.pop()) { handler(x); }
break;
}
}
//console.log(messageBuf[startPoint]);
}
if (cpCount < 2) {
// no checkpoints.
for (var x = msgBuff2.pop(); x; x = msgBuff2.pop()) { handler(x); }
}
cb(messageBuf);
});
};
const randName = function () { return Crypto.randomBytes(16).toString('hex'); };
const handleMessage = function (ctx, user, msg) {
let json = JSON.parse(msg);
let seq = json.shift();
let cmd = json[0];
let obj = json[1];
user.timeOfLastMessage = now();
user.pingOutstanding = false;
if (cmd === 'JOIN') {
if (obj && obj.length !== 32) {
sendMsg(ctx, user, [seq, 'ERROR', 'ENOENT', obj]);
return;
}
let chanName = obj || randName();
sendMsg(ctx, user, [seq, 'JACK', chanName]);
let chan = ctx.channels[chanName] = ctx.channels[chanName] || [];
// prevent removal of the channel if there is a pending timeout
if (ctx.config.removeChannels && ctx.timeouts[chanName]) {
clearTimeout(ctx.timeouts[chanName]);
}
chan.id = chanName;
if (USE_HISTORY_KEEPER) {
sendMsg(ctx, user, [0, HISTORY_KEEPER_ID, 'JOIN', chanName]);
}
chan.forEach(function (u) { sendMsg(ctx, user, [0, u.id, 'JOIN', chanName]); });
chan.push(user);
sendChannelMessage(ctx, chan, [user.id, 'JOIN', chanName]);
return;
}
if (cmd === 'MSG') {
if (obj === HISTORY_KEEPER_ID) {
let parsed;
try { parsed = JSON.parse(json[2]); } catch (err) { console.error(err); return; }
if (parsed[0] === 'GET_HISTORY') {
sendMsg(ctx, user, [seq, 'ACK']);
getHistory(ctx, parsed[1], function (msg) {
sendMsg(ctx, user, [0, HISTORY_KEEPER_ID, 'MSG', user.id, JSON.stringify(msg)]);
}, function (messages) {
// parsed[2] is a validation key if it exists
if (messages.length === 0 && parsed[2] && !historyKeeperKeys[parsed[1]]) {
var key = {channel: parsed[1], validateKey: parsed[2]};
storeMessage(ctx, ctx.channels[parsed[1]], JSON.stringify(key));
historyKeeperKeys[parsed[1]] = parsed[2];
}
let parsedMsg = {state: 1, channel: parsed[1]};
sendMsg(ctx, user, [0, HISTORY_KEEPER_ID, 'MSG', user.id, JSON.stringify(parsedMsg)]);
});
}
return;
}
if (obj && !ctx.channels[obj] && !ctx.users[obj]) {
sendMsg(ctx, user, [seq, 'ERROR', 'ENOENT', obj]);
return;
}
sendMsg(ctx, user, [seq, 'ACK']);
let target;
json.unshift(user.id);
if ((target = ctx.channels[obj])) {
sendChannelMessage(ctx, target, json);
return;
}
if ((target = ctx.users[obj])) {
json.unshift(0);
sendMsg(ctx, target, json);
return;
}
}
if (cmd === 'LEAVE') {
let err;
let chan;
let idx;
if (!obj) { err = 'EINVAL'; obj = 'undefined';}
if (!err && !(chan = ctx.channels[obj])) { err = 'ENOENT'; }
if (!err && (idx = chan.indexOf(user)) === -1) { err = 'NOT_IN_CHAN'; }
if (err) {
sendMsg(ctx, user, [seq, 'ERROR', err, obj]);
return;
}
sendMsg(ctx, user, [seq, 'ACK']);
json.unshift(user.id);
sendChannelMessage(ctx, chan, [user.id, 'LEAVE', chan.id]);
chan.splice(idx, 1);
}
if (cmd === 'PING') {
sendMsg(ctx, user, [seq, 'ACK']);
return;
}
};
let run = module.exports.run = function (storage, socketServer, config) {
/* Channel removal timeout defaults to 60000ms (one minute) */
config.channelRemovalTimeout =
typeof(config.channelRemovalTimeout) === 'number'?
config.channelRemovalTimeout:
60000;
let ctx = {
users: {},
channels: {},
timeouts: {},
store: storage,
config: config
};
setInterval(function () {
Object.keys(ctx.users).forEach(function (userId) {
let u = ctx.users[userId];
if (now() - u.timeOfLastMessage > LAG_MAX_BEFORE_DISCONNECT) {
dropUser(ctx, u);
} else if (!u.pingOutstanding && now() - u.timeOfLastMessage > LAG_MAX_BEFORE_PING) {
sendMsg(ctx, u, [0, '', 'PING', now()]);
u.pingOutstanding = true;
}
});
}, 5000);
socketServer.on('connection', function(socket) {
if(socket.upgradeReq.url !== '/cryptpad_websocket') { return; }
let conn = socket.upgradeReq.connection;
let user = {
addr: conn.remoteAddress + '|' + conn.remotePort,
socket: socket,
id: randName(),
timeOfLastMessage: now(),
pingOutstanding: false
};
ctx.users[user.id] = user;
sendMsg(ctx, user, [0, '', 'IDENT', user.id]);
socket.on('message', function(message) {
if (ctx.config.logToStdout) { console.log('>'+message); }
try {
handleMessage(ctx, user, message);
} catch (e) {
console.log(e.stack);
dropUser(ctx, user);
}
});
socket.on('close', function (evt) {
for (let userId in ctx.users) {
if (ctx.users[userId].socket === socket) {
dropUser(ctx, ctx.users[userId]);
}
}
});
});
};
}());