unblocker/lib/redirects.js

Web proxy for evading internet censorship & general-purpose library for rewriting remote websites.

"use strict";

var debug = require("debug")("unblocker:redirects");

module.exports = function (/*config*/) {
  function proxyRedirects(data) {
    // fix absolute url redirects
    // (relative redirects will be re-redirected to the correct path, and they're disallowed by the RFC anyways)
    // '//' redirects makes unblocker add the http/https before appending the url to it
    if (
      data.headers.location &&
      (data.headers.location.substr(0, 4) == "http" ||
        data.headers.location.substr(0, 2) == "//")
    ) {
      var location =
        data.clientRequest.thisSite() +
        (data.headers.location.substr(0, 2) == "//"
          ? data.url.substr(0, 5) === "https"
            ? "https:"
            : "http:"
          : "") +
        data.headers.location;
      data.redirectUrl =
        (data.headers.location.substr(0, 2) == "//"
          ? data.url.substr(0, 5) === "https"
            ? "https:"
            : "http:"
          : "") + data.headers.location; // the cookie handler uses this to know to possibly copy cookies between protocols or subdomains
      debug(
        "rewriting redirect from %s to %s",
        data.headers.location,
        location
      );
      data.headers.location = location;
    }
  }

  return proxyRedirects;
};