Pure JavaScript WebSocket Server with Ping-Pong, Handshake Upgrade, AES Encrypt, Decrypt and Authentication functionalities.

app.js

const express = require("express")
const WebSocket = require('ws')
const app = express()
const server = require('http').createServer(app)
const wss = new WebSocket.Server({ noServer: true })
const wschandler = require('./wschandler').from(wss, server)

wss.on('connection', (ws, req) => {

    console.log('connection', req.socket.remoteAddress, ws.data.token)

    ws.on('close', (reason) => {
        console.log('close', req.socket.remoteAddress, ws.data.token)
    })

    ws.on('message', (message) => {
        console.log('message', message, ws.data.token)
    })
})

app.get('/', (req, res) => {
    res.sendStatus(200)
})

server.listen(3002, () => console.log(`Server is running at 0.0.0.0:3002`))

wschandler.js

const url = require('url')
const CryptoJS = require("crypto-js")

class WSCHandler {

    constructor() {
        this.wss
        this.server
    }

    from(wss, server) {

        this.wss = wss
        this.server = server

        this.server.on('upgrade', (req, socket, head) => {
            console.log('upgrade', socket.remoteAddress, req.url)
            this.wssauthenticate(req, (client, error) => {
                if (error || !client) {
                    let headers = 'HTTP/1.1 401 Unauthorized\r\n'
                    if (error === 429) headers = 'HTTP/1.1 429 Too Many Requests\r\n'
                    headers += 'Connection: close\r\n'
                    socket.write(headers + '\r\n')
                    socket.destroy()
                } else {
                    this.wss.handleUpgrade(req, socket, head, (ws) => {
                        ws.data = client
                        ws.isAlive = true;
                        ws.on('pong', () => {
                            console.log('pong-from', JSON.stringify(ws.data))
                            ws.isAlive = true
                        })
                        this.wss.emit('connection', ws, req)
                    })
                }
            })
        })

        setInterval(() => {
            console.log('ping-clients', this.wss.clients.size)
            this.wss.clients.forEach((ws) => {
                if (ws.isAlive === false) return ws.terminate()
                ws.isAlive = false
                ws.ping(() => { })
            })
        }, 10000)
    }

    wssauthenticate(req, callback) {
        const query = url.parse(req.url, true).query;
        const device = this.decrypt(query.device)
        const token = this.decrypt(query.token)
        const pos = query.pos
        const client = { token, device, pos }
        console.log('wssauthenticate', client)
        if (client.token !== 'AUTH4ECR2PAYABLE') {
            callback(null, 401)
        } else if (Array.from(this.wss.clients).findIndex(ws => ws.data.pos === client.pos && ws.data.device === client.device && ws.data.token === client.token) > -1) {
            callback(null, 429)
        } else {
            callback(client)
        }
    }

    encrypt(data) {
        if (!data) return null
        try {
            return CryptoJS.AES.encrypt(data, CryptoJS.enc.Utf8.parse("NdRgUkXp2s5v8y/A"), {
                mode: CryptoJS.mode.ECB,
                padding: CryptoJS.pad.Pkcs7
            }).toString();
        } catch {
            return null
        }
    }

    decrypt(data) {
        if (!data) return null
        try {
            return CryptoJS.AES.decrypt(data, CryptoJS.enc.Utf8.parse("NdRgUkXp2s5v8y/A"), {
                mode: CryptoJS.mode.ECB,
                padding: CryptoJS.pad.Pkcs7
            }).toString(CryptoJS.enc.Utf8)
        } catch {
            return null
        }
    }
}

module.exports = new WSCHandler();

// const encrypt = (data) => {
//     if (!data) return null
//     try {
//         return CryptoJS.AES.encrypt(data, CryptoJS.enc.Utf8.parse("NdRgUkXp2s5v8y/A"), {
//             mode: CryptoJS.mode.ECB,
//             padding: CryptoJS.pad.Pkcs7
//         }).toString();
//     } catch {
//         return null
//     }
// }

// const decrypt = (data) => {
//     if (!data) return null
//     try {
//         return CryptoJS.AES.decrypt(data, CryptoJS.enc.Utf8.parse("NdRgUkXp2s5v8y/A"), {
//             mode: CryptoJS.mode.ECB,
//             padding: CryptoJS.pad.Pkcs7
//         }).toString(CryptoJS.enc.Utf8)
//     } catch {
//         return null
//     }
// }

// const wssauthenticate = (req, callback) => {
//     const query = url.parse(req.url, true).query;
//     const device = decrypt(query.device)
//     const token = decrypt(query.token)
//     const pos = query.pos
//     const client = { token, device, pos }
//     console.log('wssauthenticate', client)
//     if (client.token !== 'AUTH4ECR2PAYABLE') {
//         callback(null, 401)
//     } else if (Array.from(wss.clients).findIndex(ws => ws.data.pos === client.pos && ws.data.device === client.device && ws.data.token === client.token) > -1) {
//         callback(null, 429)
//     } else {
//         callback(client)
//     }
// }

// const ping = setInterval(() => {
//     console.log('ping-clients', wss.clients.size)
//     wss.clients.forEach((ws) => {
//         if (ws.isAlive === false) return ws.terminate()
//         ws.isAlive = false
//         ws.ping(() => { })
//     })
// }, 10000)

// server.on('upgrade', (req, socket, head) => {
//     console.log('upgrade', socket.remoteAddress, req.url)
//     wssauthenticate(req, (client, error) => {
//         if (error || !client) {
//             let headers = 'HTTP/1.1 401 Unauthorized\r\n'
//             if (error === 429) headers = 'HTTP/1.1 429 Too Many Requests\r\n'
//             headers += 'Connection: close\r\n'
//             socket.write(headers + '\r\n')
//             socket.destroy()
//         } else {
//             wss.handleUpgrade(req, socket, head, (ws) => {
//                 ws.data = client
//                 ws.isAlive = true;
//                 ws.on('pong', () => {
//                     console.log('pong-from', JSON.stringify(ws.data))
//                     ws.isAlive = true
//                 })
//                 wss.emit('connection', ws, req)
//             })
//         }
//     })
// })