Netlify Edge Function Basic Auth authorization

netlify-edge-basicauth.ts

import type { Config, Context } from "@netlify/edge-functions";

// https://datatracker.ietf.org/doc/html/rfc7617
// base64 encoded "user:pass"
const USER_PASS_ENCODED = "dXNlcjpwYXNz";

export default async (request: Request, context: Context) => {
  const requestAuthentication = () => {
    const response = new Response(null, {
      status: 401,
      headers: {
        "WWW-Authenticate": 'Basic realm="secret area"',
      },
    });
    return response;
  };

  const authHeader = request.headers.get("authorization");
  if (authHeader === null) {
    return requestAuthentication();
  }

  const [basic, userPass] = authHeader.split(" ");
  if (basic.toLowerCase() !== "basic") {
    return requestAuthentication();
  }

  // https://datatracker.ietf.org/doc/html/rfc7617
  if (userPass !== USER_PASS_ENCODED) {
    return requestAuthentication();
  }

  return context.next();
};

export const config: Config = {
  path: "/*",
};