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import gc
import time
from xml.dom import minidom
from django.core import serializers
from django.core.serializers.xml_serializer import Deserializer, DTDForbidden
from django.db import models
from django.test import TestCase, TransactionTestCase
from .tests import SerializersTestBase, SerializersTransactionTestBase
class XmlSerializerTestCase(SerializersTestBase, TestCase):
serializer_name = "xml"
pkless_str = """<?xml version="1.0" encoding="utf-8"?>
<django-objects version="1.0">
<object model="serializers.category">
<field type="CharField" name="name">Reference</field>
</object>
<object model="serializers.category">
<field type="CharField" name="name">Non-fiction</field>
</object>
</django-objects>"""
mapping_ordering_str = """<?xml version="1.0" encoding="utf-8"?>
<django-objects version="1.0">
<object model="serializers.article" pk="%(article_pk)s">
<field name="author" rel="ManyToOneRel" to="serializers.author">%(author_pk)s</field>
<field name="headline" type="CharField">Poker has no place on ESPN</field>
<field name="pub_date" type="DateTimeField">2006-06-16T11:00:00</field>
<field name="categories" rel="ManyToManyRel" to="serializers.category"><object pk="%(first_category_pk)s"></object><object pk="%(second_category_pk)s"></object></field>
<field name="meta_data" rel="ManyToManyRel" to="serializers.categorymetadata"></field>
<field name="topics" rel="ManyToManyRel" to="serializers.topic"></field>
</object>
</django-objects>""" # NOQA
@staticmethod
def _validate_output(serial_str):
try:
minidom.parseString(serial_str)
except Exception:
return False
else:
return True
@staticmethod
def _get_pk_values(serial_str):
ret_list = []
dom = minidom.parseString(serial_str)
fields = dom.getElementsByTagName("object")
for field in fields:
ret_list.append(field.getAttribute("pk"))
return ret_list
@staticmethod
def _get_field_values(serial_str, field_name):
ret_list = []
dom = minidom.parseString(serial_str)
fields = dom.getElementsByTagName("field")
for field in fields:
if field.getAttribute("name") == field_name:
temp = []
for child in field.childNodes:
temp.append(child.nodeValue)
ret_list.append("".join(temp))
return ret_list
def test_control_char_failure(self):
"""
Serializing control characters with XML should fail as those characters
are not supported in the XML 1.0 standard (except HT, LF, CR).
"""
self.a1.headline = "This contains \u0001 control \u0011 chars"
msg = "Article.headline (pk:%s) contains unserializable characters" % self.a1.pk
with self.assertRaisesMessage(ValueError, msg):
serializers.serialize(self.serializer_name, [self.a1])
self.a1.headline = "HT \u0009, LF \u000A, and CR \u000D are allowed"
self.assertIn(
"HT \t, LF \n, and CR \r are allowed",
serializers.serialize(self.serializer_name, [self.a1]),
)
def test_no_dtd(self):
"""
The XML deserializer shouldn't allow a DTD.
This is the most straightforward way to prevent all entity definitions
and avoid both external entities and entity-expansion attacks.
"""
xml = (
'<?xml version="1.0" standalone="no"?>'
'<!DOCTYPE example SYSTEM "http://example.com/example.dtd">'
)
with self.assertRaises(DTDForbidden):
next(serializers.deserialize("xml", xml))
def test_crafted_xml_performance(self):
"""The time to process invalid inputs is not quadratic."""
def build_crafted_xml(depth, leaf_text_len):
nested_open = "<nested>" * depth
nested_close = "</nested>" * depth
leaf = "x" * leaf_text_len
field_content = f"{nested_open}{leaf}{nested_close}"
return f"""
<django-objects version="1.0">
<object model="contenttypes.contenttype" pk="1">
<field name="app_label">{field_content}</field>
<field name="model">m</field>
</object>
</django-objects>
"""
def deserialize(crafted_xml):
iterator = Deserializer(crafted_xml)
gc.collect()
start_time = time.perf_counter()
result = list(iterator)
end_time = time.perf_counter()
self.assertEqual(len(result), 1)
self.assertIsInstance(result[0].object, models.Model)
return end_time - start_time
def assertFactor(label, params, factor=2):
factors = []
prev_time = None
for depth, length in params:
crafted_xml = build_crafted_xml(depth, length)
elapsed = deserialize(crafted_xml)
if prev_time is not None:
factors.append(elapsed / prev_time)
prev_time = elapsed
with self.subTest(label):
# Assert based on the average factor to reduce test flakiness.
self.assertLessEqual(sum(factors) / len(factors), factor)
assertFactor(
"varying depth, varying length",
[(50, 2000), (100, 4000), (200, 8000), (400, 16000), (800, 32000)],
2,
)
assertFactor("constant depth, varying length", [(100, 1), (100, 1000)], 2)
class XmlSerializerTransactionTestCase(
SerializersTransactionTestBase, TransactionTestCase
):
serializer_name = "xml"
fwd_ref_str = """<?xml version="1.0" encoding="utf-8"?>
<django-objects version="1.0">
<object pk="1" model="serializers.article">
<field to="serializers.author" name="author" rel="ManyToOneRel">1</field>
<field type="CharField" name="headline">Forward references pose no problem</field>
<field type="DateTimeField" name="pub_date">2006-06-16T15:00:00</field>
<field to="serializers.category" name="categories" rel="ManyToManyRel">
<object pk="1"></object>
</field>
<field to="serializers.categorymetadata" name="meta_data" rel="ManyToManyRel"></field>
</object>
<object pk="1" model="serializers.author">
<field type="CharField" name="name">Agnes</field>
</object>
<object pk="1" model="serializers.category">
<field type="CharField" name="name">Reference</field></object>
</django-objects>""" # NOQA
|
