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kasu/utils/html_cleaner.py
2014-11-26 13:13:07 +01:00

65 lines
2.4 KiB
Python

'''
Created on 19.10.2011
@author: christian
'''
from BeautifulSoup import BeautifulSoup
class HtmlCleaner(object):
ACCEPTABLE_ELEMENTS = ['a', 'abbr', 'acronym', 'address', 'area', 'b',
'big', 'blockquote', 'br', 'button', 'caption', 'center', 'cite',
'code', 'col', 'colgroup', 'dd', 'del', 'dfn', 'dir', 'div', 'dl',
'dt', 'em', 'font', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr', 'i',
'img', 'ins', 'kbd', 'label', 'legend', 'li', 'map', 'menu', 'ol',
'p', 'pre', 'q', 's', 'samp', 'small', 'span', 'strike',
'strong', 'sub', 'sup', 'table', 'tbody', 'td', 'tfoot', 'th',
'thead', 'tr', 'tt', 'u', 'ul', 'var']
ACCEPTABELE_ATTRIBUTES = [
'abbr', 'accept', 'accept-charset', 'accesskey',
'action', 'align', 'class', 'alt', 'axis',
'char', 'charoff', 'charset', 'checked', 'cite', 'clear', 'cols',
'colspan', 'color', 'compact', 'coords', 'datetime', 'dir',
'enctype', 'for', 'headers', 'height', 'href', 'hreflang', 'hspace',
'id', 'ismap', 'label', 'lang', 'longdesc', 'maxlength', 'method',
'multiple', 'name', 'nohref', 'noshade', 'nowrap', 'prompt',
'rel', 'rev', 'rows', 'rowspan', 'rules', 'scope', 'shape', 'size',
'span', 'src', 'start', 'summary', 'tabindex', 'target', 'title',
'type', 'usemap', 'valign', 'value', 'vspace', 'width']
counter = 1
tag_removed = False
def clean_attributes(self, tag):
for attr in tag._getAttrMap().keys():
if attr not in self.ACCEPTABELE_ATTRIBUTES:
del tag[attr]
elif tag[attr].count('script:'):
del tag[attr]
def clean_tag(self, tag):
if tag.name not in self.ACCEPTABLE_ELEMENTS:
tag.extract() # remove the bad ones
self.tag_removed = True
else:
self.clean_attributes(tag)
def clean_html(self, fragment=''):
'''
Reparses and cleans the html from XSS Attacks until it stops changing.
@param fragment:
'''
while True:
soup = BeautifulSoup(fragment)
self.tag_removed = False
self.counter += 1
for tag in soup.findAll(True):
self.clean_tag(tag)
fragment = unicode(soup)
if self.tag_removed:
continue
else:
break
return fragment