codekingpro/portable-devtools

1# defusedxml2#3# Copyright (c) 2013 by Christian Heimes <christian@python.org>4# Licensed to PSF under a Contributor Agreement.5# See https://www.python.org/psf/license for licensing details.6"""Common constants, exceptions and helpe functions7"""8import sys9import xml.parsers.expat10 11PY3 = sys.version_info[0] == 312 13# Fail early when pyexpat is not installed correctly14if not hasattr(xml.parsers.expat, "ParserCreate"):15    raise ImportError("pyexpat")  # pragma: no cover16 17 18class DefusedXmlException(ValueError):19    """Base exception"""20 21    def __repr__(self):22        return str(self)23 24 25class DTDForbidden(DefusedXmlException):26    """Document type definition is forbidden"""27 28    def __init__(self, name, sysid, pubid):29        super(DTDForbidden, self).__init__()30        self.name = name31        self.sysid = sysid32        self.pubid = pubid33 34    def __str__(self):35        tpl = "DTDForbidden(name='{}', system_id={!r}, public_id={!r})"36        return tpl.format(self.name, self.sysid, self.pubid)37 38 39class EntitiesForbidden(DefusedXmlException):40    """Entity definition is forbidden"""41 42    def __init__(self, name, value, base, sysid, pubid, notation_name):43        super(EntitiesForbidden, self).__init__()44        self.name = name45        self.value = value46        self.base = base47        self.sysid = sysid48        self.pubid = pubid49        self.notation_name = notation_name50 51    def __str__(self):52        tpl = "EntitiesForbidden(name='{}', system_id={!r}, public_id={!r})"53        return tpl.format(self.name, self.sysid, self.pubid)54 55 56class ExternalReferenceForbidden(DefusedXmlException):57    """Resolving an external reference is forbidden"""58 59    def __init__(self, context, base, sysid, pubid):60        super(ExternalReferenceForbidden, self).__init__()61        self.context = context62        self.base = base63        self.sysid = sysid64        self.pubid = pubid65 66    def __str__(self):67        tpl = "ExternalReferenceForbidden(system_id='{}', public_id={})"68        return tpl.format(self.sysid, self.pubid)69 70 71class NotSupportedError(DefusedXmlException):72    """The operation is not supported"""73 74 75def _apply_defusing(defused_mod):76    assert defused_mod is sys.modules[defused_mod.__name__]77    stdlib_name = defused_mod.__origin__78    __import__(stdlib_name, {}, {}, ["*"])79    stdlib_mod = sys.modules[stdlib_name]80    stdlib_names = set(dir(stdlib_mod))81    for name, obj in vars(defused_mod).items():82        if name.startswith("_") or name not in stdlib_names:83            continue84        setattr(stdlib_mod, name, obj)85    return stdlib_mod86 87 88def _generate_etree_functions(DefusedXMLParser, _TreeBuilder, _parse, _iterparse):89    """Factory for functions needed by etree, dependent on whether90    cElementTree or ElementTree is used."""91 92    def parse(source, parser=None, forbid_dtd=False, forbid_entities=True, forbid_external=True):93        if parser is None:94            parser = DefusedXMLParser(95                target=_TreeBuilder(),96                forbid_dtd=forbid_dtd,97                forbid_entities=forbid_entities,98                forbid_external=forbid_external,99            )100        return _parse(source, parser)101 102    def iterparse(103        source,104        events=None,105        parser=None,106        forbid_dtd=False,107        forbid_entities=True,108        forbid_external=True,109    ):110        if parser is None:111            parser = DefusedXMLParser(112                target=_TreeBuilder(),113                forbid_dtd=forbid_dtd,114                forbid_entities=forbid_entities,115                forbid_external=forbid_external,116            )117        return _iterparse(source, events, parser)118 119    def fromstring(text, forbid_dtd=False, forbid_entities=True, forbid_external=True):120        parser = DefusedXMLParser(121            target=_TreeBuilder(),122            forbid_dtd=forbid_dtd,123            forbid_entities=forbid_entities,124            forbid_external=forbid_external,125        )126        parser.feed(text)127        return parser.close()128 129    return parse, iterparse, fromstring130