TLS Client

A TLS client implementation in typescript. This library is fully compatible with the browser (without any polyfills) and on Node Js.

As all the cryptography is handled by webcrypto -- running on React native requires a polyfill for the "WebCrypto" module.

Dependencies

1. The ChaCha20-Poly1305 cipher is not supported via WebCrypto -- so we utilise @stablelib/chacha20-poly1305 to provide this functionality.
2. To handle X509 certificate validation we utilise @peculiar/x509

Supported Crypto Suites & Versions

TLS

• TLS 1.2
• TLS 1.3

Curves

• X25519 (only on NodeJs -- not supported in the browser)
• P-256 (SECP256R1)
• P-384 (SECP384R1)

Signature Algorithms

• RSA-PSS-RSAE-SHA256
• ECDSA-SECP256R1-SHA256
• ECDSA-SECP384R1-SHA384
• RSA-PKCS1-SHA256
• RSA-PKCS1-SHA512

Cipher Suites (TLS 1.3)

• AES-128-GCM-SHA256
• AES-256-GCM-SHA384
• CHACHA20-POLY1305-SHA256

Cipher Suites (TLS 1.2)

• TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
• TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
• TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
• TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
• TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
• TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
• TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
• TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA

Note: AES-CBC only works correctly on NodeJs.

Certificates

• The entire Mozilla CA store is supported
• A few additional certificates have also been added. See src/utils/root-ca.ts

Install

Edge version:

npm i git+https://gitlab.reclaimprotocol.org/Reclaim/tls

Example Usage

import { Socket } from 'net'
import { makeTLSClient, uint8ArrayToStr } from '@reclaimprotocol/tls'

const socket = new Socket()
const host = 'www.google.com'
const port = 443

const tls = makeTLSClient({
	host,
	// verify the server's certificate
	// disable when using self-signed certificates
	// or if you don't care about the authenticity
	// of the server
	verifyServerCertificate: true,
	// only use the following cipher suites
	// leave undefined to use all supported cipher suites
	cipherSuites: [
		'TLS_CHACHA20_POLY1305_SHA256'
		// ... other suites
	],
	// write raw bytes to the socket
	async write({ header, content }) {
		socket.write(header)
		socket.write(content)
	},
	onHandshake() {
		console.log('handshake completed successfully')
		// write encrypted data to the socket
		const getReq = `GET / HTTP/1.1\r\nHost: ${host}\r\n\r\n`
		tls.write(Buffer.from(getReq))
	},
	onApplicationData(plaintext) {
		const str = uint8ArrayToStr(plaintext)
		console.log('received application data: ', str)
	},
	onTlsEnd(error) {
		console.error('TLS connect ended: ', error)
	}
})

socket.on('data', tls.handleReceivedBytes)

// start handshake as soon as the socket connects
socket.on('connect', () => tls.startHandshake())

// use the TCP socket to connect to the server
socket.connect({ host, port })

Misc API Usage

Handle a Session Ticket & Resume Session with a PSK

const tlsClient = makeTlsClient({
	// ... other options
	onSessionTicket(ticket) {
		// get a PSK (pre-shared key) from the session ticket
		const psk = tls.getPskFromTicket(ticket)
		// this can be used to resume a session
		// if disconnected, using
		// tls.startHandshake({ psk })
	}
})

Handle received certificates

const tlsClient = makeTlsClient({
	// ... other options

	// handle received certificates
	// (if you want to for some reason)
	onRecvCertificates({ certificates }) {
		// do something I guess?
	}
})

Use the TLS KeyUpdate method to update the traffic keys. This sends a KeyUpdate message to the server & generates a fresh set of keys to encrypt/decrypt data. The server will then respond with a KeyUpdate message of its own. This is useful for forward secrecy.

await tls.updateTrafficKeys()