From 3905e7e64059b45479894ba1fdfb0ef9cef64475 Mon Sep 17 00:00:00 2001 From: James Taylor Date: Sat, 16 Feb 2019 23:41:52 -0800 Subject: basic subscriptions system --- python/defusedxml/expatbuilder.py | 110 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 python/defusedxml/expatbuilder.py (limited to 'python/defusedxml/expatbuilder.py') diff --git a/python/defusedxml/expatbuilder.py b/python/defusedxml/expatbuilder.py new file mode 100644 index 0000000..0eb6b91 --- /dev/null +++ b/python/defusedxml/expatbuilder.py @@ -0,0 +1,110 @@ +# defusedxml +# +# Copyright (c) 2013 by Christian Heimes +# 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) -- cgit v1.2.3