Block on TLS

JavaScript

export default {
  async fetch(request) {
    try {
      const tlsVersion = request.cf.tlsVersion;
      // Allow only TLS versions 1.2 and 1.3
      if (tlsVersion !== "TLSv1.2" && tlsVersion !== "TLSv1.3") {
        return new Response("Please use TLS version 1.2 or higher.", {
          status: 403,
        });
      }
      return fetch(request);
    } catch (err) {
      console.error(
        "request.cf does not exist in the previewer, only in production",
      );
      return new Response(`Error in workers script ${err.message}`, {
        status: 500,
      });
    }
  },
};

TypeScript

export default {
  async fetch(request): Promise<Response> {
    try {
      const tlsVersion = request.cf.tlsVersion;
      // Allow only TLS versions 1.2 and 1.3
      if (tlsVersion !== "TLSv1.2" && tlsVersion !== "TLSv1.3") {
        return new Response("Please use TLS version 1.2 or higher.", {
          status: 403,
        });
      }
      return fetch(request);
    } catch (err) {
      console.error(
        "request.cf does not exist in the previewer, only in production",
      );
      return new Response(`Error in workers script ${err.message}`, {
        status: 500,
      });
    }
  },
} satisfies ExportedHandler;

Hono

import { Hono } from "hono";

const app = new Hono();

// Middleware to check TLS version
app.use("*", async (c, next) => {
  // Access the raw request to get the cf object with TLS info
  const request = c.req.raw;
  const tlsVersion = request.cf?.tlsVersion;

  // Allow only TLS versions 1.2 and 1.3
  if (tlsVersion !== "TLSv1.2" && tlsVersion !== "TLSv1.3") {
    return c.text("Please use TLS version 1.2 or higher.", 403);
  }

  await next();

});

app.onError((err, c) => {
    console.error(
      "request.cf does not exist in the previewer, only in production",
    );
    return c.text(`Error in workers script: ${err.message}`, 500);
});

app.get("/", async (c) => {
  return c.text(`TLS Version: ${c.req.raw.cf.tlsVersion}`);
});

export default app;

Python

from workers import Response, fetch

async def on_fetch(request):
    tls_version = request.cf.tlsVersion
    if tls_version not in ("TLSv1.2", "TLSv1.3"):
        return Response("Please use TLS version 1.2 or higher.", status=403)
    return fetch(request)