gistfile1.txt

from  burp import IBurpExtender,IProxyListener

class BurpExtender(IBurpExtender,IProxyListener):
    def registerExtenderCallbacks(self,callbacks):
        self._helpers = callbacks.getHelpers()
        self._callbacks = callbacks
        self._callbacks.setExtensionName("IProxyListener Params")
        self._callbacks.registerProxyListener(self)

    def processProxyMessage(self,messageIsRequest,message):
        if messageIsRequest:
            msg = message.getMessageInfo()
            req_bytes = msg.getRequest() # RAW Request in Bytes
            req = self._helpers.analyzeRequest(req_bytes)
            req_params = req.getParameters() ## this would be in list 
            param_list = []
            for param in req_params:
               new_param = self._helpers.buildParameter(param.getName(),"XXXXXXXXX",param.getType())
               param_list.append(new_param)
            new_request = self._helpers.updateParameter(req_bytes,param_list)
            msg.setRequest(new_request)