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# defusedxml
#
# Copyright (c) 2013 by Christian Heimes <christian@python.org>
# Licensed to PSF under a Contributor Agreement.
# See http://www.python.org/psf/license for licensing details.
"""Defused xml.dom.expatbuilder
"""
from __future__ import print_function, absolute_import
from xml.dom.expatbuilder import ExpatBuilder as _ExpatBuilder
from xml.dom.expatbuilder import Namespaces as _Namespaces
from .common import (DTDForbidden, EntitiesForbidden,
ExternalReferenceForbidden)
__origin__ = "xml.dom.expatbuilder"
class DefusedExpatBuilder(_ExpatBuilder):
"""Defused document builder"""
def __init__(self, options=None, forbid_dtd=False, forbid_entities=True,
forbid_external=True):
_ExpatBuilder.__init__(self, options)
self.forbid_dtd = forbid_dtd
self.forbid_entities = forbid_entities
self.forbid_external = forbid_external
def defused_start_doctype_decl(self, name, sysid, pubid,
has_internal_subset):
raise DTDForbidden(name, sysid, pubid)
def defused_entity_decl(self, name, is_parameter_entity, value, base,
sysid, pubid, notation_name):
raise EntitiesForbidden(name, value, base, sysid, pubid, notation_name)
def defused_unparsed_entity_decl(self, name, base, sysid, pubid,
notation_name):
# expat 1.2
raise EntitiesForbidden(name, None, base, sysid, pubid, notation_name)
def defused_external_entity_ref_handler(self, context, base, sysid,
pubid):
raise ExternalReferenceForbidden(context, base, sysid, pubid)
def install(self, parser):
_ExpatBuilder.install(self, parser)
if self.forbid_dtd:
parser.StartDoctypeDeclHandler = self.defused_start_doctype_decl
if self.forbid_entities:
# if self._options.entities:
parser.EntityDeclHandler = self.defused_entity_decl
parser.UnparsedEntityDeclHandler = self.defused_unparsed_entity_decl
if self.forbid_external:
parser.ExternalEntityRefHandler = self.defused_external_entity_ref_handler
class DefusedExpatBuilderNS(_Namespaces, DefusedExpatBuilder):
"""Defused document builder that supports namespaces."""
def install(self, parser):
DefusedExpatBuilder.install(self, parser)
if self._options.namespace_declarations:
parser.StartNamespaceDeclHandler = (
self.start_namespace_decl_handler)
def reset(self):
DefusedExpatBuilder.reset(self)
self._initNamespaces()
def parse(file, namespaces=True, forbid_dtd=False, forbid_entities=True,
forbid_external=True):
"""Parse a document, returning the resulting Document node.
'file' may be either a file name or an open file object.
"""
if namespaces:
build_builder = DefusedExpatBuilderNS
else:
build_builder = DefusedExpatBuilder
builder = build_builder(forbid_dtd=forbid_dtd,
forbid_entities=forbid_entities,
forbid_external=forbid_external)
if isinstance(file, str):
fp = open(file, 'rb')
try:
result = builder.parseFile(fp)
finally:
fp.close()
else:
result = builder.parseFile(file)
return result
def parseString(string, namespaces=True, forbid_dtd=False,
forbid_entities=True, forbid_external=True):
"""Parse a document from a string, returning the resulting
Document node.
"""
if namespaces:
build_builder = DefusedExpatBuilderNS
else:
build_builder = DefusedExpatBuilder
builder = build_builder(forbid_dtd=forbid_dtd,
forbid_entities=forbid_entities,
forbid_external=forbid_external)
return builder.parseString(string)
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