From 7bf4baa92134009050018c73efee8d34f8c436ce Mon Sep 17 00:00:00 2001
From: Tobias Berger <tobi.berger13@gmail.com>
Date: Sat, 8 Jan 2022 17:17:43 +0100
Subject: [PATCH] Several changes

~Use TLS properly
+Generate author IDs from Salted IPs
~Change port
+Add start script
---
 .gitignore     |  3 +-
 package.json   |  6 ++--
 server.node.ts | 94 ++++++++++++++++++++++++++++++++++++++++----------
 3 files changed, 81 insertions(+), 22 deletions(-)

diff --git a/.gitignore b/.gitignore
index 7190e32..522e90d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,4 +3,5 @@
 !*.config.js
 .rollup.cache
 tsconfig.tsbuildinfo
-node_modules
\ No newline at end of file
+node_modules
+*.pem
\ No newline at end of file
diff --git a/package.json b/package.json
index 09e2a47..7651a8b 100644
--- a/package.json
+++ b/package.json
@@ -2,11 +2,13 @@
   "name": "web-drs-backend",
   "version": "1.0.0",
   "description": "",
-  "main": "server.js",
+  "main": "server.node.bundle.js",
   "directories": {
     "lib": "lib"
   },
   "scripts": {
+    "dev": "yarn build && yarn start",
+    "start": "node server.node.bundle.js",
     "build": "rollup --config ./rollup.config.js"
   },
   "repository": {
@@ -28,4 +30,4 @@
     "typescript": "^4.5.4",
     "ws": "^8.4.0"
   }
-}
+}
\ No newline at end of file
diff --git a/server.node.ts b/server.node.ts
index b34fd6b..b3d494c 100644
--- a/server.node.ts
+++ b/server.node.ts
@@ -1,39 +1,87 @@
+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/types/ServerMessage";
+} from "./lib/ServerMessage";
 
-const port = 8989;
+const SALT = crypto
+  .randomBytes(Math.round(Math.random() * 1024))
+  .toString("hex");
+
+const port = 8085;
 const timeout = 15000;
 
-const server = new WebSocketServer({port});
+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);
 
-server.on("connection", function connection(socket) {
-  function close() {
-    socket.send("closing connection due to inactivity");
-    socket.close();
+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) {
-    console.log("message: " + rawMessage);
-
     const message = JSON.parse(rawMessage);
     if (!isServerMessage(message)) {
       console.error(`Unexpected message received from client \`${message}\``);
     }
     if (isTextMessage(message)) {
-      socket.send(
-        JSON.stringify({
-          type: MessageType.TEXT,
-          date: Date.now(),
-          author: "ECHO Service",
-          content: message.content,
-        }),
-      );
+      handleTextMessage(message, authorID);
     }
     clearTimeout(closeTimeout);
     closeTimeout = setTimeout(close, timeout);
@@ -42,7 +90,15 @@ server.on("connection", function connection(socket) {
     console.log("closed a connection");
   });
 
-  console.log("new client connected!");
-  socket.send("connected");
+  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);