Enriched UDP Socket and Client

Enriched UDP Socket and Client with possibility to encrypt data and send big messages.

• Fast — small overhead above UDP to send messages
• Secure — built-in encryption for sensitive logs
• Universal – built-in fragmentation to send big messages
• Simple — used well-known Node streams to manipulate and move data
• ESM and CJS

Install

npm i --save e-socket-udp

Fast Start

//client.js
import { UDPClient } from 'e-socket-udp'

const secret = '11223344556677889900aabbccddeeff11223344556677889900aabbccddeeff'
const client = new UDPClient({ encryption: secret })

client.write(Buffer.from('Hello, World!', 'utf8'))

//server.js
import { UDPSocket } from 'e-socket-udp'

const secret = '11223344556677889900aabbccddeeff11223344556677889900aabbccddeeff'
const socket = new UDPSocket({ decryption: secret })

for await (const message of socket) {
  console.log(message)
}

After just start the server node server.js and client node app.js. That's all and everything works.

Documentation

class UDPClient

Extends Basic UDPClient.

Arguments:

• options <object> – optional
  • type <'udp4' | 'udp6'> – optional. Inherited. Default 'udp4'
  • port <string | number> – optional. Inherited. Default 44302
  • address <string> – optional. Inherited. Default '127.0.0.1' or '::1'
  • encryption <string> | <(payload: Buffer) => Buffer> – optional. Default undefined
    • if passed string - will be applied aes-256-ctr encryption with passed string as a secret, so it should be 64char long;
    • if passed function - this function will be used to encrypt every message;
    • if passed undefined - will not use any kind of encryption.
  • fragmentation <boolean> – optional. Automatically split each message into chunks. Useful with any size of messages (especially big ones). Default true
  • packetSize <number> – optional. Used if fragmentation = true. Number of bytes in each packet (chunk). Default 1280

Methods:

• write (buffer): <boolean> — Inherited.

Fields:

• origin: <dgram.Socket> — Inherited.
• port: <number> — Inherited.
• address: <string> — Inherited.
• family: <string> — Inherited.

Events:

• 'ready': <void> – Inherited. Emitted when the client "establishes" udp connection.

Usage

Simple example with encryption

import { UDPClient } from 'e-socket-udp'

const client = new UDPClient({
  port: 44302,
  // encryption: (buf) => buf.map(byte => byte ^ 83)
  encryption: '11223344556677889900aabbccddeeff11223344556677889900aabbccddeeff'
})

client.write(Buffer.from('Hello, world!', 'utf8'))

---

class UDPSocket

Extends Basic UDPSocket

It is a UDP socket in readable stream form with encoding and possibility to handle big messages.

Arguments:

• options <object> – required
  • type <'udp4' | 'udp6'> – optional. Inherited. Default 'udp4'
  • port <string | number> – optional. Inherited. Default 44302
  • host <string> – optional. Inherited. Default '127.0.0.1' or '::1'
  • decryption <string> | <(payload: Buffer) => Buffer> – optional. Default undefined
    • if passed string - will be applied aes-256-ctr decryption with passed string as a secret, so it should be 64char long;
    • if passed function - will be used that function to decrypt every message;
    • if passed undefined - will not use any kind of decryption.
  • fragmentation <boolean> – optional. Combine chunks into message. Useful with any size of messages (especially big ones). Default true
  • gcIntervalTime <number> — optional. How often instance will check internal buffer to delete expired messages (in ms). Default 5000
  • gcExpirationTime <number>— optional. How long chunks can await all missing chunks in internal buffer (in ms). Default 10000

Fields:

• origin: <dgram.Socket> — Inherited.
• port: <number> — Inherited.
• address: <string> — Inherited.
• family: <string> — Inherited.
• allowPush: <boolean> — Inherited.

Events:

All Readable events of course and:

Event: 'ready' — Inherited.

Emitted when socket started and ready to receive data.

Event: 'warning'

Emitted when warning occurs.

• message <object | Error>
  • type <Symbol>
  • id <string> – optional
  • date <Date> – optional

A type might be:

• Symbol<'missing_message'> – when some messages didn't receive all chunks and got expired.
• Symbol<'decryption_message'> – when some messages failed to be compiled from chunks.

Usage

Example how to use pure socket as async generator

import { UDPSocket } from 'e-socket-udp'

const socket = new UDPsocket({
  port: 44302,
  // decryption: (buf) => buf.map(byte => byte ^ 83) // not safe at all, but better than nothing
  decryption: '11223344556677889900aabbccddeeff11223344556677889900aabbccddeeff'
})

for await (const message of socket) {
  /*handle messages*/
}

Example how to use socket and fs write stream

import fs from 'node:fs'
import { UDPSocket } from 'e-socket-udp'

const secret = '11223344556677889900aabbccddeeff11223344556677889900aabbccddeeff'

const writer = fs.createWriteStream('/some/path')
const socket = new UDPSocket({ port: 44302, decryption: secret })

socket.pipe(writer)

---

Additional Exposed variables and functions

constant DEFAULT_PORT

• <number> : 44302

constant WARNING_MISSING_MESSAGE

• <Symbol> : Symbol<'missing_message'>

constant WARNING_DECRYPTION_FAIL

• <Symbol> : Symbol<'decryption_fail'>

---

There are _identifier and _constants exposed also, but they are used for internal needs. They could be removed in next releases, so it is not recommended to use it in your project.

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License (MIT)