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web-drs-backend/server.node.ts
Tobias Berger 46a243669e
Several changes
~Use TLS properly
+Generate author IDs from Salted IPs
~Change port
+Add start script
2022-02-28 11:32:23 +01:00

104 lines
2.7 KiB
TypeScript

import * as fs from "fs";
import * as https from "https";
import { WebSocketServer } from "ws";
import * as crypto from "crypto";
import type { AckMessage, TextMessage } from "./lib/ServerMessage";
import {
isServerMessage,
isTextMessage,
MessageType,
} from "./lib/ServerMessage";
const SALT = crypto
.randomBytes(Math.round(Math.random() * 1024))
.toString("hex");
const port = 8085;
const timeout = 15000;
const httpsServer = https.createServer({
key: fs.readFileSync("./key.pem"),
cert: fs.readFileSync("./cert.pem"),
});
const webSocketServer = new WebSocketServer({ server: httpsServer });
console.log("listening on port: " + port);
function hash(str: string) {
return crypto.createHash("SHAKE256").update(str, "utf-8").digest("hex");
}
async function handleTextMessage(message: TextMessage, from: string) {
for (const to of webSocketServer.clients) {
to.send(
JSON.stringify(
Object.assign({}, message, {
author: from,
})
)
);
}
}
webSocketServer.on("connection", function connection(socket, request) {
const close = (reason: string, code: number = 1000) => {
socket.send(
JSON.stringify({
type: MessageType.ACK,
date: Date.now(),
__ctx: `closing connection. reason: ${reason}`,
} as AckMessage)
);
socket.close(code, `closing connection. reason: ${reason}`);
};
let authorID: string;
{
let ip: string | undefined;
if (request.headers["x-forwarded-for"] !== undefined) {
const forwardedFor = request.headers["x-forwarded-for"];
ip =
typeof forwardedFor === "string"
? forwardedFor.split(",")[0]?.trim()
: forwardedFor[0];
} else {
ip = request.socket.remoteAddress;
}
if (ip === undefined) {
close("could not generate author id", 1008);
console.error("connection without IP. closing.");
return;
}
authorID = hash(ip + SALT);
}
socket.on("message", function (rawMessage: string) {
const message = JSON.parse(rawMessage);
if (!isServerMessage(message)) {
console.error(`Unexpected message received from client \`${message}\``);
}
if (isTextMessage(message)) {
handleTextMessage(message, authorID);
}
clearTimeout(closeTimeout);
closeTimeout = setTimeout(close, timeout);
});
socket.on("close", function close() {
console.log("closed a connection");
});
console.log("new client connected! ID:", authorID);
socket.send(
JSON.stringify({
type: MessageType.ACK,
date: Date.now(),
__ctx: "connected successfully",
} as AckMessage)
);
let closeTimeout = setTimeout(close, timeout);
});
httpsServer.listen(port);