'Plugin entry point, find the SSN numbers.
:param request: The HTTP request object.
:param response: The HTTP response object
:return: None.'

def grep(self, request, response):

    if ((not response.is_text_or_html()) or (response.get_code() != 200) or (response.get_clear_text_body() is None)):
        return
    (found_ssn, validated_ssn) = self._find_SSN(response.get_clear_text_body())
    if validated_ssn:
        uri = response.get_uri()
        desc = 'The    URL:    "%s"    possibly    discloses    a    US    Social    Security    Number:    "%s".'
        desc = (desc % (uri, validated_ssn))
        v = Vuln('US    Social    Security    Number    disclosure', desc, severity.LOW, response.id, self.get_name())
        v.set_uri(uri)
        v.add_to_highlight(found_ssn)
        self.kb_append_uniq(self, 'ssn', v, 'URL')
