dns-over-http

HTTP(s) middleware and client for DNS over HTTPS (DoH)

Abstract

DNS over HTTPS (DoH) is protocol designed for performing remote Domain Name System resolution over HTTPS. Requests are made of HTTP to increase user security and privacy. See DNS over HTTPS for more information.

This module provides a middleware function that can be directly passed to the http.createServer() and https.createServer() functions for handling DNS resolution. This module will use centralized DNS servers for DNS queries and will cache answers from them for subsequent requests. This module is a work-in-progres.

Installation

$ npm install dns-over-http

Usage

Creating a server

const https = require('https')
const doh = require('dns-over-http')

const serverOptions = getServerOptions() // with cert and key
const server = https.createServer(serverOptions, doh({
  maxAge: 1000 * 60 * 10, // 10 minute max TTL for any DNS record
  // centralized DNS servers
  servers: [
    '9.9.9.9', // quad9
    '8.8.8.8', // google
    '1.1.1.1', // cloudflare
  ]
}))

server.listen(3000)

You can also use the http module and position it behind a load balancer or nginx instance configured SSL certificates.

*Querying for DNS resolution

const doh = require('dns-over-http')
const url = 'https://dns.google.com:443/experimental'

const results = []
const lookups = [
  {type: 'A', name: 'google.com'},
  {type: 'A', name: 'littlstar.com'},
  {type: 'A', name: 'twitter.com'},
]

for (const lookup of lookups) {
  doh.query({url}, [lookup], (err, res) => {
    if (err) { throw err }
    results.push(res.answers)
    if (results.length == lookups.length) {
      console.log(results)
    }
  })
}

API

doh(opts)

Returns a function handle suitable for a http server request callback where opts can be:

{
  servers: ['dns.example.com'], // centralized DNS servers
  store: null, // an optional storage interface
}

doh.query(opts, questions, cb)

Make a DNS resolution query request. Options are passed directly to the http.request function. questions are given to a dns-packet encoding and sent as a POST request with a 'application/dns-udpwireformat' content type.

See Also

• dns-packet
• dns-socket
• DNS over HTTPS
• 1.1.1.1
• Google Public DNS

License

MIT