#!/usr/bin/env python

"""
$Id$

Copyright (c) 2006-2011 sqlmap developers (http://sqlmap.sourceforge.net/)
See the file 'doc/COPYING' for copying permission
"""

import re

from lib.core.common import getCompiledRegex
from lib.core.common import readXmlFile
from lib.core.convert import urldecode
from lib.core.data import conf
from lib.core.data import paths
from lib.core.data import logger

rules = None

def __adjustGrammar(string):
    string = re.sub('\ADetects', 'Detected', string)
    string = re.sub('\Afinds', 'Found', string)
    string = re.sub('attempts\Z', 'attempt', string)
    string = re.sub('injections\Z', 'injection', string)
    string = re.sub('attacks\Z', 'attack', string)

    return string

def checkPayload(payload):
    """
    This method checks if the generated payload is detectable by the
    PHPIDS filter rules
    """

    if not payload:
        return

    global rules

    detected = False
    payload = urldecode(payload)

    if not rules:
        xmlrules = readXmlFile(paths.PHPIDS_RULES_XML)
        rules = []

        for xmlrule in xmlrules.getElementsByTagName("filter"):
            rule = "(?i)%s" % xmlrule.getElementsByTagName('rule')[0].childNodes[0].nodeValue
            desc = __adjustGrammar(xmlrule.getElementsByTagName('description')[0].childNodes[0].nodeValue)
            rules.append((rule, desc))

    if payload:
        for rule, desc in rules:
            regObj = getCompiledRegex(rule)

            if regObj.search(payload):
                detected = True
                logger.warn("highly probable IDS/IPS detection: '%s: %s'" % (desc, payload))

    if not detected:
        logger.warn("payload '%s' possibly gone undetected" % payload)