The Tor Browser / file revision

 const CC = Components.Constructor;

 const BinaryInputStream = CC("@mozilla.org/binaryinputstream;1",

                              "nsIBinaryInputStream",

                              "setInputStream");

 function handleRequest(request, response) {

   response.setHeader("Content-Type", "text/plain", false);

   if (request.method == "GET") {

     response.write(request.queryString);

   } else {

     var body = new BinaryInputStream(request.bodyInputStream);

     var avail;

     var bytes = [];

     while ((avail = body.available()) > 0)

       Array.prototype.push.apply(bytes, body.readByteArray(avail));

     var data = String.fromCharCode.apply(null, bytes);

     response.bodyOutputStream.write(data, data.length);

   }

 }