basic subscriptions system

1 files changed, 112 insertions, 0 deletions

diff --git a/python/defusedxml/ElementTree.py b/python/defusedxml/ElementTree.py
new file mode 100644
index 0000000..41b2ea8
--- /dev/null
+++ b/python/defusedxml/ElementTree.py
@@ -0,0 +1,112 @@
+# 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.etree.ElementTree facade
+"""
+from __future__ import print_function, absolute_import
+
+import sys
+from xml.etree.ElementTree import TreeBuilder as _TreeBuilder
+from xml.etree.ElementTree import parse as _parse
+from xml.etree.ElementTree import tostring
+
+from .common import PY3
+
+
+if PY3:
+    import importlib
+else:
+    from xml.etree.ElementTree import XMLParser as _XMLParser
+    from xml.etree.ElementTree import iterparse as _iterparse
+    from xml.etree.ElementTree import ParseError
+
+
+from .common import (DTDForbidden, EntitiesForbidden,
+                     ExternalReferenceForbidden, _generate_etree_functions)
+
+__origin__ = "xml.etree.ElementTree"
+
+
+def _get_py3_cls():
+    """Python 3.3 hides the pure Python code but defusedxml requires it.
+
+    The code is based on test.support.import_fresh_module().
+    """
+    pymodname = "xml.etree.ElementTree"
+    cmodname = "_elementtree"
+
+    pymod = sys.modules.pop(pymodname, None)
+    cmod = sys.modules.pop(cmodname, None)
+
+    sys.modules[cmodname] = None
+    pure_pymod = importlib.import_module(pymodname)
+    if cmod is not None:
+        sys.modules[cmodname] = cmod
+    else:
+        sys.modules.pop(cmodname)
+    sys.modules[pymodname] = pymod
+
+    _XMLParser = pure_pymod.XMLParser
+    _iterparse = pure_pymod.iterparse
+    ParseError = pure_pymod.ParseError
+
+    return _XMLParser, _iterparse, ParseError
+
+
+if PY3:
+    _XMLParser, _iterparse, ParseError = _get_py3_cls()
+
+
+class DefusedXMLParser(_XMLParser):
+
+    def __init__(self, html=0, target=None, encoding=None,
+                 forbid_dtd=False, forbid_entities=True,
+                 forbid_external=True):
+        # Python 2.x old style class
+        _XMLParser.__init__(self, html, target, encoding)
+        self.forbid_dtd = forbid_dtd
+        self.forbid_entities = forbid_entities
+        self.forbid_external = forbid_external
+        if PY3:
+            parser = self.parser
+        else:
+            parser = self._parser
+        if self.forbid_dtd:
+            parser.StartDoctypeDeclHandler = self.defused_start_doctype_decl
+        if self.forbid_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
+
+    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)
+
+
+# aliases
+XMLTreeBuilder = XMLParse = DefusedXMLParser
+
+parse, iterparse, fromstring = _generate_etree_functions(DefusedXMLParser,
+                                                         _TreeBuilder, _parse,
+                                                         _iterparse)
+XML = fromstring
+
+
+__all__ = ['XML', 'XMLParse', 'XMLTreeBuilder', 'fromstring', 'iterparse',
+           'parse', 'tostring']