You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
154 lines
4.8 KiB
154 lines
4.8 KiB
2 years ago
|
# defusedxml
|
||
|
#
|
||
|
# Copyright (c) 2013 by Christian Heimes <christian@python.org>
|
||
|
# Licensed to PSF under a Contributor Agreement.
|
||
|
# See https://www.python.org/psf/license for licensing details.
|
||
|
"""DEPRECATED Example code for lxml.etree protection
|
||
|
|
||
|
The code has NO protection against decompression bombs.
|
||
|
"""
|
||
|
from __future__ import print_function, absolute_import
|
||
|
|
||
|
import threading
|
||
|
import warnings
|
||
|
|
||
|
from lxml import etree as _etree
|
||
|
|
||
|
from .common import DTDForbidden, EntitiesForbidden, NotSupportedError
|
||
|
|
||
|
LXML3 = _etree.LXML_VERSION[0] >= 3
|
||
|
|
||
|
__origin__ = "lxml.etree"
|
||
|
|
||
|
tostring = _etree.tostring
|
||
|
|
||
|
|
||
|
warnings.warn(
|
||
|
"defusedxml.lxml is no longer supported and will be removed in a future release.",
|
||
|
category=DeprecationWarning,
|
||
|
stacklevel=2,
|
||
|
)
|
||
|
|
||
|
|
||
|
class RestrictedElement(_etree.ElementBase):
|
||
|
"""A restricted Element class that filters out instances of some classes"""
|
||
|
|
||
|
__slots__ = ()
|
||
|
# blacklist = (etree._Entity, etree._ProcessingInstruction, etree._Comment)
|
||
|
blacklist = _etree._Entity
|
||
|
|
||
|
def _filter(self, iterator):
|
||
|
blacklist = self.blacklist
|
||
|
for child in iterator:
|
||
|
if isinstance(child, blacklist):
|
||
|
continue
|
||
|
yield child
|
||
|
|
||
|
def __iter__(self):
|
||
|
iterator = super(RestrictedElement, self).__iter__()
|
||
|
return self._filter(iterator)
|
||
|
|
||
|
def iterchildren(self, tag=None, reversed=False):
|
||
|
iterator = super(RestrictedElement, self).iterchildren(tag=tag, reversed=reversed)
|
||
|
return self._filter(iterator)
|
||
|
|
||
|
def iter(self, tag=None, *tags):
|
||
|
iterator = super(RestrictedElement, self).iter(tag=tag, *tags)
|
||
|
return self._filter(iterator)
|
||
|
|
||
|
def iterdescendants(self, tag=None, *tags):
|
||
|
iterator = super(RestrictedElement, self).iterdescendants(tag=tag, *tags)
|
||
|
return self._filter(iterator)
|
||
|
|
||
|
def itersiblings(self, tag=None, preceding=False):
|
||
|
iterator = super(RestrictedElement, self).itersiblings(tag=tag, preceding=preceding)
|
||
|
return self._filter(iterator)
|
||
|
|
||
|
def getchildren(self):
|
||
|
iterator = super(RestrictedElement, self).__iter__()
|
||
|
return list(self._filter(iterator))
|
||
|
|
||
|
def getiterator(self, tag=None):
|
||
|
iterator = super(RestrictedElement, self).getiterator(tag)
|
||
|
return self._filter(iterator)
|
||
|
|
||
|
|
||
|
class GlobalParserTLS(threading.local):
|
||
|
"""Thread local context for custom parser instances"""
|
||
|
|
||
|
parser_config = {
|
||
|
"resolve_entities": False,
|
||
|
# 'remove_comments': True,
|
||
|
# 'remove_pis': True,
|
||
|
}
|
||
|
|
||
|
element_class = RestrictedElement
|
||
|
|
||
|
def createDefaultParser(self):
|
||
|
parser = _etree.XMLParser(**self.parser_config)
|
||
|
element_class = self.element_class
|
||
|
if self.element_class is not None:
|
||
|
lookup = _etree.ElementDefaultClassLookup(element=element_class)
|
||
|
parser.set_element_class_lookup(lookup)
|
||
|
return parser
|
||
|
|
||
|
def setDefaultParser(self, parser):
|
||
|
self._default_parser = parser
|
||
|
|
||
|
def getDefaultParser(self):
|
||
|
parser = getattr(self, "_default_parser", None)
|
||
|
if parser is None:
|
||
|
parser = self.createDefaultParser()
|
||
|
self.setDefaultParser(parser)
|
||
|
return parser
|
||
|
|
||
|
|
||
|
_parser_tls = GlobalParserTLS()
|
||
|
getDefaultParser = _parser_tls.getDefaultParser
|
||
|
|
||
|
|
||
|
def check_docinfo(elementtree, forbid_dtd=False, forbid_entities=True):
|
||
|
"""Check docinfo of an element tree for DTD and entity declarations
|
||
|
|
||
|
The check for entity declarations needs lxml 3 or newer. lxml 2.x does
|
||
|
not support dtd.iterentities().
|
||
|
"""
|
||
|
docinfo = elementtree.docinfo
|
||
|
if docinfo.doctype:
|
||
|
if forbid_dtd:
|
||
|
raise DTDForbidden(docinfo.doctype, docinfo.system_url, docinfo.public_id)
|
||
|
if forbid_entities and not LXML3:
|
||
|
# lxml < 3 has no iterentities()
|
||
|
raise NotSupportedError("Unable to check for entity declarations " "in lxml 2.x")
|
||
|
|
||
|
if forbid_entities:
|
||
|
for dtd in docinfo.internalDTD, docinfo.externalDTD:
|
||
|
if dtd is None:
|
||
|
continue
|
||
|
for entity in dtd.iterentities():
|
||
|
raise EntitiesForbidden(entity.name, entity.content, None, None, None, None)
|
||
|
|
||
|
|
||
|
def parse(source, parser=None, base_url=None, forbid_dtd=False, forbid_entities=True):
|
||
|
if parser is None:
|
||
|
parser = getDefaultParser()
|
||
|
elementtree = _etree.parse(source, parser, base_url=base_url)
|
||
|
check_docinfo(elementtree, forbid_dtd, forbid_entities)
|
||
|
return elementtree
|
||
|
|
||
|
|
||
|
def fromstring(text, parser=None, base_url=None, forbid_dtd=False, forbid_entities=True):
|
||
|
if parser is None:
|
||
|
parser = getDefaultParser()
|
||
|
rootelement = _etree.fromstring(text, parser, base_url=base_url)
|
||
|
elementtree = rootelement.getroottree()
|
||
|
check_docinfo(elementtree, forbid_dtd, forbid_entities)
|
||
|
return rootelement
|
||
|
|
||
|
|
||
|
XML = fromstring
|
||
|
|
||
|
|
||
|
def iterparse(*args, **kwargs):
|
||
|
raise NotSupportedError("defused lxml.etree.iterparse not available")
|