Gavatar proxy via Cloudflare Worker

gavatar.js

const host = "secure.gravatar.com";
const defaultSize = "512";

addEventListener("fetch", function(event) {
  event.respondWith(handleRequest(event.request))
})

async function handleRequest(request) {
  // Check referer.
  let referer = request.headers.get("referer")
  if (referer) {
    try {
      let ru = new URL(referer);
      if (ru.host != "moy.cat" && !ru.host.endsWith(".moy.cat")) {
        return new Response("forbidden", {status: 403});
      }
    } catch (e) {}
  }
  let u = new URL(request.url);
  u.host = host;
  return fetch(u.toString(), {
    headers: request.headers,
  })
}