254 lines
7.3 KiB
JavaScript
254 lines
7.3 KiB
JavaScript
// A WebSocket to TCP socket proxy
|
|
// Copyright 2010 Joel Martin
|
|
// Licensed under LGPL version 3 (see docs/LICENSE.LGPL-3)
|
|
|
|
var net = require('net'),
|
|
sys = require('sys'),
|
|
crypto = require('crypto'),
|
|
source_arg, source_host, source_port,
|
|
target_arg, target_host, target_port;
|
|
|
|
// md5 calculation borrowed from Socket.IO (MIT license)
|
|
function gen_md5(headers, k3) {
|
|
var k1 = headers['sec-websocket-key1'],
|
|
k2 = headers['sec-websocket-key2'],
|
|
md5 = crypto.createHash('md5');
|
|
|
|
[k1, k2].forEach(function(k){
|
|
var n = parseInt(k.replace(/[^\d]/g, '')),
|
|
spaces = k.replace(/[^ ]/g, '').length;
|
|
|
|
if (spaces === 0 || n % spaces !== 0){
|
|
return false;
|
|
}
|
|
|
|
n /= spaces;
|
|
|
|
md5.update(String.fromCharCode(
|
|
n >> 24 & 0xFF,
|
|
n >> 16 & 0xFF,
|
|
n >> 8 & 0xFF,
|
|
n & 0xFF));
|
|
});
|
|
|
|
md5.update(k3.toString('binary'));
|
|
|
|
return md5.digest('binary');
|
|
}
|
|
|
|
function encode(buf) {
|
|
return String.fromCharCode(0) +
|
|
buf.toString('base64', 0) +
|
|
String.fromCharCode(255);
|
|
}
|
|
|
|
function decode(data) {
|
|
var i, len = 0, strs, retstrs = [],
|
|
buf = new Buffer(data.length),
|
|
str = data.toString('binary', 1, data.length-1);
|
|
|
|
if (str.indexOf('\xff') > -1) {
|
|
// We've gotten multiple frames at once
|
|
strs = str.split('\xff\x00')
|
|
for (i = 0; i < strs.length; i++) {
|
|
len = buf.write(strs[i], 0, 'base64');
|
|
retstrs.push(buf.toString('binary', 0, len));
|
|
}
|
|
return retstrs.join("");
|
|
} else {
|
|
len = buf.write(str, 0, 'base64');
|
|
return buf.toString('binary', 0, len);
|
|
}
|
|
}
|
|
|
|
|
|
var server = net.createServer(function (client) {
|
|
var handshake = "", headers = {}, header,
|
|
version, path, k1, k2, k3, target = null;
|
|
|
|
function cleanup() {
|
|
client.end();
|
|
if (target) {
|
|
target.end();
|
|
target = null;
|
|
}
|
|
}
|
|
|
|
function do_handshake(data) {
|
|
var i, idx, dlen = data.length, lines, location, rheaders,
|
|
sec_hdr;
|
|
//sys.log("received handshake data: " + data);
|
|
handshake += data.toString('utf8');
|
|
if ((data[dlen-12] != 13) ||
|
|
(data[dlen-11] != 10) ||
|
|
(data[dlen-10] != 13) ||
|
|
(data[dlen-9] != 10)) {
|
|
//sys.log("Got partial handshake");
|
|
return;
|
|
}
|
|
//sys.log("Got whole handshake");
|
|
|
|
if (handshake.indexOf('GET ') != 0) {
|
|
sys.error("Got invalid handshake");
|
|
client.end();
|
|
return;
|
|
}
|
|
|
|
lines = handshake.split('\r\n');
|
|
path = lines[0].split(' ')[1];
|
|
//sys.log("path: " + path);
|
|
|
|
k3 = data.slice(dlen-8, dlen);
|
|
for (i = 1; i < lines.length; i++) {
|
|
//sys.log("lines[i]: " + lines[i]);
|
|
if (lines[i].length == 0) { break; }
|
|
idx = lines[i].indexOf(': ');
|
|
if (idx < 0) {
|
|
sys.error("Got invalid handshake header");
|
|
client.end();
|
|
return;
|
|
}
|
|
header = lines[i].slice(0, idx).toLowerCase();
|
|
headers[header] = lines[i].slice(idx+2);
|
|
}
|
|
//console.dir(headers);
|
|
//sys.log("k3: " + k3 + ", k3.length: " + k3.length);
|
|
|
|
if (headers.upgrade !== 'WebSocket') {
|
|
sys.error("Upgrade header is not 'WebSocket'");
|
|
client.end();
|
|
return;
|
|
}
|
|
|
|
location = (headers.origin.substr(0, 5) == 'https' ? 'wss' : 'ws')
|
|
+ '://' + headers.host + path;
|
|
//sys.log("location: " + location);
|
|
|
|
if ('sec-websocket-key1' in headers) {
|
|
version = 76;
|
|
sec_hdr = "Sec-";
|
|
} else {
|
|
version = 75;
|
|
sec_hdr = "";
|
|
}
|
|
sys.log("using protocol version " + version);
|
|
|
|
rheaders = [
|
|
'HTTP/1.1 101 WebSocket Protocol Handshake',
|
|
'Upgrade: WebSocket',
|
|
'Connection: Upgrade',
|
|
sec_hdr + 'WebSocket-Origin: ' + headers.origin,
|
|
sec_hdr + 'WebSocket-Location: ' + location
|
|
];
|
|
if ('sec-websocket-protocol' in headers) {
|
|
rheaders.push('Sec-WebSocket-Protocol: ' + headers['sec-websocket-protocol']);
|
|
}
|
|
rheaders.push('');
|
|
if (version === 76) {
|
|
rheaders.push(gen_md5(headers, k3));
|
|
}
|
|
|
|
// Switch listener to normal data path
|
|
client.on('data', client_data);
|
|
//client.setEncoding('utf8');
|
|
client.removeListener('data', do_handshake);
|
|
// Do not delay writes
|
|
client.setNoDelay(true);
|
|
|
|
// Send the handshake response
|
|
try {
|
|
//sys.log("response: " + rheaders.join('\r\n'));
|
|
client.write(rheaders.join('\r\n'), 'binary');
|
|
} catch(e) {
|
|
sys.error("Failed to send handshake response");
|
|
client.end();
|
|
return;
|
|
}
|
|
|
|
// Create a connection to the target
|
|
target = net.createConnection(target_port, target_host);
|
|
target.on('data', target_data);
|
|
target.on('end', function () {
|
|
sys.log("received target end");
|
|
cleanup();
|
|
});
|
|
target.on('error', function (exc) {
|
|
sys.log("received target error: " + exc);
|
|
cleanup();
|
|
});
|
|
}
|
|
|
|
function client_data(data) {
|
|
var ret;
|
|
//sys.log("received client data: " + data);
|
|
//sys.log(" decoded: " + decode(data));
|
|
try {
|
|
ret = target.write(decode(data), 'binary');
|
|
if (! ret) {
|
|
sys.log("target write returned false");
|
|
}
|
|
} catch(e) {
|
|
sys.log("fatal error writing to target");
|
|
cleanup();
|
|
}
|
|
}
|
|
|
|
function target_data(data) {
|
|
//sys.log("received target data: " + data);
|
|
//sys.log(" encoded: " + encode(data));
|
|
try {
|
|
client.write(encode(data), 'binary');
|
|
} catch(e) {
|
|
sys.log("fatal error writing to client");
|
|
cleanup();
|
|
}
|
|
}
|
|
|
|
client.on('connect', function () {
|
|
sys.log("Got client connection");
|
|
});
|
|
client.on('data', do_handshake);
|
|
client.on('end', function () {
|
|
sys.log("recieved client end");
|
|
cleanup();
|
|
});
|
|
client.on('error', function (exc) {
|
|
sys.log("recieved client error: " + exc);
|
|
cleanup();
|
|
});
|
|
});
|
|
|
|
|
|
// parse source and target into parts
|
|
source_arg = process.argv[2];
|
|
target_arg = process.argv[3];
|
|
try {
|
|
var idx;
|
|
idx = source_arg.indexOf(":");
|
|
if (idx >= 0) {
|
|
source_host = source_arg.slice(0, idx);
|
|
source_port = parseInt(source_arg.slice(idx+1), 10);
|
|
} else {
|
|
source_host = "";
|
|
source_port = parseInt(source_arg, 10);
|
|
}
|
|
|
|
idx = target_arg.indexOf(":");
|
|
if (idx < 0) {
|
|
throw("target must be host:port");
|
|
}
|
|
target_host = target_arg.slice(0, idx);
|
|
target_port = parseInt(target_arg.slice(idx+1), 10);
|
|
|
|
if (isNaN(source_port) || isNaN(target_port)) {
|
|
throw("illegal port");
|
|
}
|
|
} catch(e) {
|
|
console.error("wsproxy.py [source_addr:]source_port target_addr:target_port");
|
|
process.exit(2);
|
|
}
|
|
|
|
sys.log("source: " + source_host + ":" + source_port);
|
|
sys.log("target: " + target_host + ":" + target_port);
|
|
server.listen(source_port, source_host);
|