node-minecraft-protocol/index.js
2015-02-20 20:08:49 +00:00

389 lines
12 KiB
JavaScript

var EventEmitter = require('events').EventEmitter
, util = require('util')
, assert = require('assert')
, crypto = require('crypto')
, bufferEqual = require('buffer-equal')
, superagent = require('superagent')
, protocol = require('./lib/protocol')
, Client = require('./lib/client')
, Server = require('./lib/server')
, Yggdrasil = require('./lib/yggdrasil.js')
, getSession = Yggdrasil.getSession
, validateSession = Yggdrasil.validateSession
, joinServer = Yggdrasil.joinServer
, states = protocol.states
, debug = protocol.debug
;
var ursa;
try {
ursa = require("ursa");
} catch(e) {
console.log("You are using a pure-javascript implementation of RSA.");
console.log("Your performance might be subpar. Please consider installing URSA");
ursa = require("./rsa-wrap");
}
module.exports = {
createClient: createClient,
createServer: createServer,
Client: Client,
Server: Server,
ping: require('./lib/ping'),
protocol: protocol,
yggdrasil: Yggdrasil,
};
function createServer(options) {
options = options || {};
var port = options.port != null ?
options.port :
options['server-port'] != null ?
options['server-port'] :
25565;
var host = options.host || '0.0.0.0';
var kickTimeout = options.kickTimeout || 10 * 1000;
var checkTimeoutInterval = options.checkTimeoutInterval || 4 * 1000;
var onlineMode = options['online-mode'] == null ? true : options['online-mode'];
var serverKey = ursa.generatePrivateKey(1024);
var server = new Server(options);
server.motd = options.motd || "A Minecraft server";
server.maxPlayers = options['max-players'] || 20;
server.playerCount = 0;
server.onlineModeExceptions = {};
server.on("connection", function(client) {
client.once([states.HANDSHAKING, 0x00], onHandshake);
client.once([states.LOGIN, 0x00], onLogin);
client.once([states.STATUS, 0x00], onPing);
client.on('end', onEnd);
var keepAlive = false;
var loggedIn = false;
var lastKeepAlive = null;
var keepAliveTimer = null;
var loginKickTimer = setTimeout(kickForNotLoggingIn, kickTimeout);
var hash;
function kickForNotLoggingIn() {
client.end('LoginTimeout');
}
function keepAliveLoop() {
if (!keepAlive)
return;
// check if the last keepAlive was too long ago (kickTimeout)
var elapsed = new Date() - lastKeepAlive;
if (elapsed > kickTimeout) {
client.end('KeepAliveTimeout');
return;
}
client.write(0x00, {
keepAliveId: Math.floor(Math.random() * 2147483648)
});
}
function onKeepAlive(packet) {
lastKeepAlive = new Date();
}
function startKeepAlive() {
keepAlive = true;
lastKeepAlive = new Date();
keepAliveTimer = setInterval(keepAliveLoop, checkTimeoutInterval);
client.on(0x00, onKeepAlive);
}
function onEnd() {
clearInterval(keepAliveTimer);
clearTimeout(loginKickTimer);
}
function onPing(packet) {
var response = {
"version": {
"name": protocol.minecraftVersion,
"protocol": protocol.version
},
"players": {
"max": server.maxPlayers,
"online": server.playerCount,
"sample": []
},
"description": {"text": server.motd},
"favicon": server.favicon
};
client.once([states.STATUS, 0x01], function(packet) {
client.write(0x01, { time: packet.time });
client.end();
});
client.write(0x00, {response: JSON.stringify(response)});
}
function onLogin(packet) {
client.username = packet.username;
var isException = !!server.onlineModeExceptions[client.username.toLowerCase()];
var needToVerify = (onlineMode && !isException) || (! onlineMode && isException);
if (needToVerify) {
var serverId = crypto.randomBytes(4).toString('hex');
client.verifyToken = crypto.randomBytes(4);
var publicKeyStrArr = serverKey.toPublicPem("utf8").split("\n");
var publicKeyStr = "";
for (var i = 1; i < publicKeyStrArr.length - 2; i++) {
publicKeyStr += publicKeyStrArr[i]
}
client.publicKey = new Buffer(publicKeyStr, 'base64');
hash = crypto.createHash("sha1");
hash.update(serverId);
client.once([states.LOGIN, 0x01], onEncryptionKeyResponse);
client.write(0x01, {
serverId: serverId,
publicKey: client.publicKey,
verifyToken: client.verifyToken
});
} else {
loginClient();
}
}
function onHandshake(packet) {
if (packet.nextState == 1) {
client.state = states.STATUS;
} else if (packet.nextState == 2) {
client.state = states.LOGIN;
}
}
function onEncryptionKeyResponse(packet) {
var verifyToken = serverKey.decrypt(packet.verifyToken, undefined, undefined, ursa.RSA_PKCS1_PADDING);
if (!bufferEqual(client.verifyToken, verifyToken)) {
client.end('DidNotEncryptVerifyTokenProperly');
return;
}
var sharedSecret = serverKey.decrypt(packet.sharedSecret, undefined, undefined, ursa.RSA_PKCS1_PADDING);
client.cipher = crypto.createCipheriv('aes-128-cfb8', sharedSecret, sharedSecret);
client.decipher = crypto.createDecipheriv('aes-128-cfb8', sharedSecret, sharedSecret);
hash.update(sharedSecret);
hash.update(client.publicKey);
client.encryptionEnabled = true;
var isException = !!server.onlineModeExceptions[client.username.toLowerCase()];
var needToVerify = (onlineMode && !isException) || (!onlineMode && isException);
var nextStep = needToVerify ? verifyUsername : loginClient;
nextStep();
function verifyUsername() {
var digest = mcHexDigest(hash);
validateSession(client.username, digest, function(err, uuid) {
if (err) {
client.end("Failed to verify username!");
return;
}
client.uuid = uuid;
// Convert to a valid UUID until the session server updates and does
// it automatically
client.uuid = client.uuid.replace(/(\w{8})(\w{4})(\w{4})(\w{4})(\w{12})/, "$1-$2-$3-$4-$5");
loginClient();
});
}
}
function loginClient() {
var isException = !!server.onlineModeExceptions[client.username.toLowerCase()];
if (onlineMode == false || isException) {
client.uuid = "0-0-0-0-0";
}
//client.write('compress', { threshold: 256 }); // Default threshold is 256
//client.compressionThreshold = 256;
client.write(0x02, {uuid: client.uuid, username: client.username});
client.state = states.PLAY;
loggedIn = true;
startKeepAlive();
clearTimeout(loginKickTimer);
loginKickTimer = null;
server.playerCount += 1;
client.once('end', function() {
server.playerCount -= 1;
});
server.emit('login', client);
}
});
server.listen(port, host);
return server;
}
function createClient(options) {
assert.ok(options, "options is required");
var port = options.port || 25565;
var host = options.host || 'localhost';
var clientToken = options.clientToken || Yggdrasil.generateUUID();
var accessToken = options.accessToken || null;
assert.ok(options.username, "username is required");
var haveCredentials = options.password != null || (clientToken != null && accessToken != null);
var keepAlive = options.keepAlive == null ? true : options.keepAlive;
var client = new Client(false);
client.on('connect', onConnect);
if (keepAlive) client.on([states.PLAY, 0x00], onKeepAlive);
client.once([states.LOGIN, 0x01], onEncryptionKeyRequest);
client.once([states.LOGIN, 0x02], onLogin);
client.once("compress", onCompressionRequest);
client.once("set_compression", onCompressionRequest);
if (haveCredentials) {
// make a request to get the case-correct username before connecting.
var cb = function(err, session) {
if (err) {
client.emit('error', err);
} else {
client.session = session;
client.username = session.username;
accessToken = session.accessToken;
client.emit('session');
client.connect(port, host);
}
};
if (accessToken != null) getSession(options.username, accessToken, options.clientToken, true, cb);
else getSession(options.username, options.password, options.clientToken, false, cb);
} else {
// assume the server is in offline mode and just go for it.
client.username = options.username;
client.connect(port, host);
}
return client;
function onConnect() {
client.write(0x00, {
protocolVersion: protocol.version,
serverHost: host,
serverPort: port,
nextState: 2
});
client.state = states.LOGIN;
client.write(0x00, {
username: client.username
});
}
function onCompressionRequest(packet) {
client.compressionThreshold = packet.threshold;
}
function onKeepAlive(packet) {
client.write(0x00, {
keepAliveId: packet.keepAliveId
});
}
function onEncryptionKeyRequest(packet) {
crypto.randomBytes(16, gotSharedSecret);
function gotSharedSecret(err, sharedSecret) {
if (err) {
debug(err);
client.emit('error', err);
client.end();
return;
}
if (haveCredentials) {
joinServerRequest(onJoinServerResponse);
} else {
if (packet.serverId != '-') {
debug('This server appears to be an online server and you are providing no password, the authentication will probably fail');
}
sendEncryptionKeyResponse();
}
function onJoinServerResponse(err) {
if (err) {
client.emit('error', err);
client.end();
} else {
sendEncryptionKeyResponse();
}
}
function joinServerRequest(cb) {
var hash = crypto.createHash('sha1');
hash.update(packet.serverId);
hash.update(sharedSecret);
hash.update(packet.publicKey);
var digest = mcHexDigest(hash);
joinServer(this.username, digest, accessToken, client.session.selectedProfile.id, cb);
}
function sendEncryptionKeyResponse() {
var pubKey = mcPubKeyToURsa(packet.publicKey);
var encryptedSharedSecretBuffer = pubKey.encrypt(sharedSecret, undefined, undefined, ursa.RSA_PKCS1_PADDING);
var encryptedVerifyTokenBuffer = pubKey.encrypt(packet.verifyToken, undefined, undefined, ursa.RSA_PKCS1_PADDING);
client.cipher = crypto.createCipheriv('aes-128-cfb8', sharedSecret, sharedSecret);
client.decipher = crypto.createDecipheriv('aes-128-cfb8', sharedSecret, sharedSecret);
client.write(0x01, {
sharedSecret: encryptedSharedSecretBuffer,
verifyToken: encryptedVerifyTokenBuffer,
});
client.encryptionEnabled = true;
}
}
}
function onLogin(packet) {
client.state = states.PLAY;
client.uuid = packet.uuid;
client.username = packet.username;
}
}
function mcPubKeyToURsa(mcPubKeyBuffer) {
var pem = "-----BEGIN PUBLIC KEY-----\n";
var base64PubKey = mcPubKeyBuffer.toString('base64');
var maxLineLength = 65;
while (base64PubKey.length > 0) {
pem += base64PubKey.substring(0, maxLineLength) + "\n";
base64PubKey = base64PubKey.substring(maxLineLength);
}
pem += "-----END PUBLIC KEY-----\n";
return ursa.createPublicKey(pem, 'utf8');
}
function mcHexDigest(hash) {
var buffer = new Buffer(hash.digest(), 'binary');
// check for negative hashes
var negative = buffer.readInt8(0) < 0;
if (negative)
performTwosCompliment(buffer);
var digest = buffer.toString('hex');
// trim leading zeroes
digest = digest.replace(/^0+/g, '');
if (negative)
digest = '-' + digest;
return digest;
function performTwosCompliment(buffer) {
var carry = true;
var i, newByte, value;
for (i = buffer.length - 1; i >= 0; --i) {
value = buffer.readUInt8(i);
newByte = ~value & 0xff;
if (carry) {
carry = newByte === 0xff;
buffer.writeUInt8((newByte + 1) & 0xff, i);
} else {
buffer.writeUInt8(newByte, i);
}
}
}
}