Simple utility for representing domain-fronted access in a single domain name.
Domain fronting is a system for connecting to a site on a CDN without revealing the destination site to a passive network adversary. This approach has been pioneered by the meek transport for Tor.
In short, domain fronting works by establishing a TLS connection to one site on the CDN (revealing the domain name in DNS queries and TLS-SNI), and then changing the HTTP host header to indicate a request to a different site on the same CDN. Most CDNs serve these queries without a problem. A hostile observer cannot determine which site the user is accessing, because the Host header is transmitted inside the TLS tunnel.
Suppose you want to use domain fronting with an existing library that performs some HTTP operations. If this library doesn't already support domain fronting, you might have to modify its network access code, effectively requiring you to maintain a fork of the library. This would be inconvenient.
This package is designed to support an alternative solution: swap out the underlying HTTP access primitives (e.g. freedom-xhr), encode the domain fronting in special domain names, and thereby add domain fronting support to existing libraries without modifying their code.
Suppose you are trying to access az786092.vo.msecnd.net, while revealing only
a front domain of ajax.aspnetcdn.com. frontdomain would encode this as a
single domain name:
ajax.aspnetcdn.com.az786092.vo.msecnd.net.3.domainfront
The two domains are simply concatenated, followed by the number of
components in the front domain, followed by the magic TLD domainfront.
var frontdomain = require('frontdomain');
var front = 'ajax.aspnetcdn.com';
var host = 'az786092.vo.msecnd.net';
var munged = frontdomain.munge(front, host);
// munged == 'ajax.aspnetcdn.com.az786092.vo.msecnd.net.3.domainfront'
var isFront = frontdomain.isFront(munged);
// isFront == true
var demunged = frontdomain.demnuge(munged);
// demunged.front == front
// demunged.host == hostLicensed under the Apache-2.0 license. Maintained by @bemasc.