add captcha support

config.example.toml

@@ -7,6 +7,11 @@ proxying = true
 # 99% of the time this will only be 127.0.0.1
 proxyAllowedIps = ["127.0.0.1"]
 
+[hcaptcha]
+enabled = false
+sitekey = ""
+secret = ""
+
 [vm]
 qemuArgs = "qemu-system-x86_64"
 vncPort = 5900

package.json

@@ -14,6 +14,7 @@
     "@types/sharp": "^0.31.1",
     "@types/ws": "^8.5.4",
     "async-mutex": "^0.4.0",
+    "axios": "^1.3.2",
     "canvas": "^2.11.0",
     "execa": "^6.1.0",
     "fs": "^0.0.1-security",

src/IConfig.ts

@@ -5,6 +5,12 @@ export default interface IConfig {
         proxying : boolean;
         proxyAllowedIps : string[];
     };
+    hcaptcha : {
+        enabled : boolean;
+        sitekey : string;
+        secret : string;
+        whitelist : string[];
+    };
     vm : {
         qemuArgs : string;
         vncPort : number;

src/User.ts

@@ -18,6 +18,7 @@ export class User {
     Config : IConfig;
     IP : string;
     vote : boolean | null;
+    captchaValidated : boolean;
     // Rate limiters
     ChatRateLimit : RateLimiter;
     LoginRateLimit : RateLimiter;
@@ -52,6 +53,7 @@ export class User {
         this.LoginRateLimit.on('limit', () => this.closeConnection());
         this.TurnRateLimit = new RateLimiter(5, 3);
         this.TurnRateLimit.on('limit', () => this.closeConnection());
+        this.captchaValidated = false;
     }
     assignGuestName(existingUsers : string[]) : string {
         var username;

src/WSServer.ts

@@ -12,6 +12,7 @@ import { createHash } from 'crypto';
 import { isIP } from 'net';
 import QEMUVM from './QEMUVM.js';
 import { Canvas, createCanvas, CanvasRenderingContext2D } from 'canvas';
+import hcaptcha from './hcaptcha.js';
 
 export default class WSServer {
     private Config : IConfig;
@@ -40,6 +41,8 @@ export default class WSServer {
     private turnsAllowed : boolean;
     // Indefinite turn
     private indefiniteTurn : User | null;
+    // Captcha
+    private captcha : hcaptcha;
     private ModPerms : number;  
     private VM : QEMUVM;
     constructor(config : IConfig, vm : QEMUVM) {
@@ -69,6 +72,7 @@ export default class WSServer {
         this.VM = vm;
         this.VM.on("dirtyrect", (j, x, y) => this.newrect(j, x, y));
         this.VM.on("size", (s) => this.newsize(s));
+        this.captcha = new hcaptcha(this.Config);
     }
 
     listen() {
@@ -131,6 +135,8 @@ export default class WSServer {
             ip = req.socket.remoteAddress;
         }
         var user = new User(ws, ip, this.Config);
+        if (this.captcha.checkIpValidated(user.IP))
+            user.captchaValidated = true;
         this.clients.push(user);
         ws.on('close', () => this.connectionClosed(user));
         ws.on('message', (e) => {
@@ -164,10 +170,14 @@ export default class WSServer {
         if (msgArr.length < 1) return;
         switch (msgArr[0]) {
             case "list":
+                if (this.Config.hcaptcha.enabled && !client.captchaValidated && this.Config.hcaptcha.whitelist.indexOf(client.IP) === -1)
+                    client.sendMsg(guacutils.encode("captcha", "0", this.Config.hcaptcha.sitekey));
                 client.sendMsg(guacutils.encode("list", this.Config.collabvm.node, this.Config.collabvm.displayname, await this.getThumbnail()));
                 break;
             case "connect":
-                if (!client.username || msgArr.length !== 2 || msgArr[1] !== this.Config.collabvm.node) {
+                if (!client.username || msgArr.length !== 2 || msgArr[1] !== this.Config.collabvm.node
+                    || (this.Config.hcaptcha.enabled && !client.captchaValidated && this.Config.hcaptcha.whitelist.indexOf(client.IP) === -1)
+                    ) {
                     client.sendMsg(guacutils.encode("connect", "0"));
                     return;
                 }
@@ -183,6 +193,16 @@ export default class WSServer {
                 if (this.voteInProgress) this.sendVoteUpdate(client);
                 this.sendTurnUpdate(client);
                 break;
+            case "captcha":
+                if (client.captchaValidated || msgArr.length !== 2) return;
+                var result = await this.captcha.validateToken(msgArr[1], client.IP);
+                if (result) {
+                    client.sendMsg(guacutils.encode("captcha", "1"));
+                    client.captchaValidated = true;
+                } else {
+                    client.sendMsg(guacutils.encode("captcha", "2"));
+                }
+                break;
             case "rename":
                 if (!client.RenameRateLimit.request()) return;
                 this.renameUser(client, msgArr[1]);

src/hcaptcha.ts

@@ -0,0 +1,31 @@
+import IConfig from "./IConfig";
+import axios from 'axios';
+import querystring from 'node:querystring';
+
+export default class hcaptcha {
+    Config : IConfig;
+    ValidIps : string[];
+    constructor(config : IConfig) {
+        this.Config = config;
+        this.ValidIps = [];
+    }
+    checkIpValidated(ip : string) : boolean {
+        return (this.ValidIps.indexOf(ip) !== -1);
+    }
+    validateToken(token : string, ip : string) : Promise<boolean> {
+        return new Promise(async (res, rej) => {
+            var response;
+            try {
+                response = await axios.post("https://hcaptcha.com/siteverify", querystring.encode({
+                    "secret": this.Config.hcaptcha.secret,
+                    "response": token,
+                    "remoteip": ip
+                }));
+            } catch (e) {rej(e); return;}
+            if (response.data.success === true) {
+                this.ValidIps.push(ip);
+            }
+            res(response.data.success);
+        })
+    }
+}