@@ -28,10 +28,19 @@ var to_send = [];

 var senders = [new XMLHttpRequest(), new XMLHttpRequest()];

 var i_sender = 1;

 var bundle_size = 0;

+var jsSHA = require("sha");

 function sendPayload(payload) {

    var data = new FormData();

    data.append(cfg_data_field, payload);

+

+   if (cfg_sign_field) {

+      var sha = new jsSHA(cfg_sign_algo, "TEXT");

+      sha.setHMACKey(cfg_sign_key, cfg_sign_key_format);

+      sha.update(payload);

+      data.append(cfg_sign_field, sha.getHMAC(cfg_sign_field_format));

+   }

+

    i_sender = 1 - i_sender;

    senders[i_sender].open("POST", cfg_endpoint, true);

    senders[i_sender].send(data);