In the Firefox agent, when connecting to an HTTPS site, you can see the OCSP requests in the object results. These requests are validating the SSL Certificate.
If you don't want to see these requests in the test, you can use the following code at the beginning of the script to filter them out.
var prefs = Components.classes["@mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefBranch); prefs.setIntPref("security.OCSP.enabled", 0);
A demo script can be downloaded: RemoveOCSP.gsl.