sqlmap/lib/request/comparison.py
2010-12-04 10:13:18 +00:00

119 lines
4.0 KiB
Python

#!/usr/bin/env python
"""
$Id$
Copyright (c) 2006-2010 sqlmap developers (http://sqlmap.sourceforge.net/)
See the file 'doc/COPYING' for copying permission
"""
import re
from difflib import SequenceMatcher
from lib.core.common import removeDynamicContent
from lib.core.common import wasLastRequestDBMSError
from lib.core.data import conf
from lib.core.data import kb
from lib.core.data import logger
from lib.core.settings import CONSTANT_RATIO
from lib.core.settings import DIFF_TOLERANCE
def comparison(page, headers=None, getSeqMatcher=False, pageLength=None):
if page is None and pageLength is None:
return None
regExpResults = None
conf.seqMatcher.set_seq1(kb.pageTemplate)
if page:
# String to be excluded before calculating page hash
if conf.eString and conf.eString in page:
index = page.index(conf.eString)
length = len(conf.eString)
pageWithoutString = page[:index]
pageWithoutString += page[index+length:]
page = pageWithoutString
# Regular expression matches to be excluded before calculating page hash
if conf.eRegexp:
regExpResults = re.findall(conf.eRegexp, page, re.I | re.M)
if regExpResults:
for regExpResult in regExpResults:
index = page.index(regExpResult)
length = len(regExpResult)
pageWithoutRegExp = page[:index]
pageWithoutRegExp += page[index+length:]
page = pageWithoutRegExp
# String to match in page when the query is valid
if conf.string:
return conf.string in page
# Regular expression to match in page when the query is valid
if conf.regexp:
return re.search(conf.regexp, page, re.I | re.M) is not None
# In case of an DBMS error page return None
if wasLastRequestDBMSError():
return None
# Dynamic content lines to be excluded before comparison
if not kb.nullConnection and not conf.longestCommon:
page = removeDynamicContent(page)
if not pageLength:
pageLength = len(page)
if kb.locks.seqLock:
kb.locks.seqLock.acquire()
if conf.longestCommon:
(firstPage, secondPage) = (conf.seqMatcher.a, page)
match = SequenceMatcher(None, firstPage, secondPage).find_longest_match(0, len(firstPage), 0, len(secondPage))
ratio = round(SequenceMatcher(None, firstPage[match[0]:match[0]+match[2]], secondPage[match[1]:match[1]+match[2]]).ratio(), 3)
elif not conf.eRegexp and not conf.eString and kb.nullConnection and pageLength:
ratio = 1. * pageLength / len(conf.seqMatcher.a)
if ratio > 1.:
ratio = 1. / ratio
else:
conf.seqMatcher.set_seq2(page)
ratio = round(conf.seqMatcher.ratio(), 3)
if kb.locks.seqLock:
kb.locks.seqLock.release()
# If the url is stable and we did not set yet the match ratio and the
# current injected value changes the url page content
if conf.matchRatio is None:
if conf.thold:
conf.matchRatio = conf.thold
elif kb.pageStable and ratio > 0.6 and ratio < 1:
conf.matchRatio = ratio
logger.debug("setting match ratio for current parameter to %.3f" % conf.matchRatio)
elif not kb.pageStable or ( kb.pageStable and ratio < 0.6 ):
conf.matchRatio = CONSTANT_RATIO
logger.debug("setting match ratio for current parameter to default value 0.900")
# If it has been requested to return the ratio and not a comparison
# response
if getSeqMatcher:
return ratio
elif ratio == 1:
return True
elif conf.matchRatio is None:
return None
else:
if conf.matchRatio == CONSTANT_RATIO or conf.thold:
return ratio > conf.matchRatio
else:
return (ratio - conf.matchRatio) > DIFF_TOLERANCE