mirror of
https://github.com/9001/copyparty.git
synced 2025-08-16 08:32:13 -06:00
try to decode some malicious xml on startup; if this succeeds, then force-disable all xml-based features (primarily WebDAV) this is paranoid future-proofing against unanticipated changes in future versions of python, specifically if the importlib or xml.etree.ET behavior changes in a way that somehow reenables entity expansion, which (still hypothetically) would probably be caused by failing to unload the `_elementtree` c-module no past or present python versions are affected by this change
161 lines
5 KiB
Python
161 lines
5 KiB
Python
#!/usr/bin/env python3
|
|
# coding: utf-8
|
|
from __future__ import print_function, unicode_literals
|
|
|
|
import re
|
|
import unittest
|
|
from xml.etree import ElementTree as ET
|
|
|
|
from copyparty.dxml import BadXML, mkenod, mktnod, parse_xml
|
|
|
|
ET.register_namespace("D", "DAV:")
|
|
|
|
|
|
def _parse(txt):
|
|
try:
|
|
parse_xml(txt)
|
|
raise Exception("unsafe")
|
|
except BadXML:
|
|
pass
|
|
|
|
|
|
class TestDXML(unittest.TestCase):
|
|
def test_qbe(self):
|
|
# allowed by default; verify that we stopped it
|
|
txt = r"""<!DOCTYPE qbe [
|
|
<!ENTITY a "nice_bakuretsu">
|
|
]>
|
|
<l>&a;&a;&a;&a;&a;&a;&a;&a;&a;</l>"""
|
|
_parse(txt)
|
|
ET.fromstring(txt)
|
|
|
|
def test_ent_file(self):
|
|
# NOT allowed by default; should still be blocked
|
|
txt = r"""<!DOCTYPE ext [
|
|
<!ENTITY ee SYSTEM "file:///bin/bash">
|
|
]>
|
|
<root>ⅇ</root>"""
|
|
_parse(txt)
|
|
try:
|
|
ET.fromstring(txt)
|
|
raise Exception("unsafe2")
|
|
except ET.ParseError:
|
|
pass
|
|
|
|
def test_ent_ext(self):
|
|
# NOT allowed by default; should still be blocked
|
|
txt = r"""<!DOCTYPE ext [
|
|
<!ENTITY ee SYSTEM "http://example.com/a.xml">
|
|
]>
|
|
<root>ⅇ</root>"""
|
|
_parse(txt)
|
|
|
|
def test_dtd(self):
|
|
# allowed by default; verify that we stopped it
|
|
txt = r"""<!DOCTYPE d SYSTEM "a.dtd">
|
|
<root>a</root>"""
|
|
_parse(txt)
|
|
ET.fromstring(txt)
|
|
|
|
##
|
|
## end of negative/security tests; the rest is functional
|
|
##
|
|
|
|
def test3(self):
|
|
txt = r"""<?xml version="1.0" ?>
|
|
<propfind xmlns="DAV:">
|
|
<prop>
|
|
<name/>
|
|
<href/>
|
|
</prop>
|
|
</propfind>
|
|
"""
|
|
txt = txt.replace("\n", "\r\n")
|
|
ET.fromstring(txt)
|
|
el = parse_xml(txt)
|
|
self.assertListEqual(
|
|
[y.tag for y in el.findall(r"./{DAV:}prop/*")],
|
|
[r"{DAV:}name", r"{DAV:}href"],
|
|
)
|
|
|
|
def test4(self):
|
|
txt = r"""<?xml version="1.0" encoding="utf-8" ?>
|
|
<D:propertyupdate xmlns:D="DAV:" xmlns:Z="urn:schemas-microsoft-com:">
|
|
<D:set>
|
|
<D:prop>
|
|
<Z:Win32CreationTime>Thu, 20 Oct 2022 02:16:33 GMT</Z:Win32CreationTime>
|
|
<Z:Win32LastAccessTime>Thu, 20 Oct 2022 02:16:35 GMT</Z:Win32LastAccessTime>
|
|
<Z:Win32LastModifiedTime>Thu, 20 Oct 2022 02:16:33 GMT</Z:Win32LastModifiedTime>
|
|
<Z:Win32FileAttributes>00000000</Z:Win32FileAttributes>
|
|
</D:prop>
|
|
</D:set>
|
|
</D:propertyupdate>"""
|
|
|
|
ref = r"""<?xml version="1.0" encoding="UTF-8"?>
|
|
<D:multistatus xmlns:D="DAV:">
|
|
<D:response>
|
|
<D:href>/d1/foo.txt</D:href>
|
|
<D:propstat>
|
|
<D:prop>
|
|
<Win32CreationTime xmlns="urn:schemas-microsoft-com:"></Win32CreationTime>
|
|
<Win32LastAccessTime xmlns="urn:schemas-microsoft-com:"></Win32LastAccessTime>
|
|
<Win32LastModifiedTime xmlns="urn:schemas-microsoft-com:"></Win32LastModifiedTime>
|
|
<Win32FileAttributes xmlns="urn:schemas-microsoft-com:"></Win32FileAttributes>
|
|
</D:prop>
|
|
<D:status>HTTP/1.1 403 Forbidden</D:status>
|
|
</D:propstat>
|
|
</D:response>
|
|
</D:multistatus>"""
|
|
|
|
txt = re.sub("\n +", "\n", txt)
|
|
root = mkenod("a")
|
|
root.insert(0, parse_xml(txt))
|
|
prop = root.find(r"./{DAV:}propertyupdate/{DAV:}set/{DAV:}prop")
|
|
assert prop is not None
|
|
assert len(prop)
|
|
for el in prop:
|
|
el.clear()
|
|
|
|
res = ET.tostring(prop).decode("utf-8")
|
|
want = """<D:prop xmlns:D="DAV:" xmlns:ns1="urn:schemas-microsoft-com:">
|
|
<ns1:Win32CreationTime /><ns1:Win32LastAccessTime /><ns1:Win32LastModifiedTime /><ns1:Win32FileAttributes /></D:prop>
|
|
"""
|
|
self.assertEqual(res, want)
|
|
|
|
def test5(self):
|
|
txt = r"""<?xml version="1.0" encoding="utf-8" ?>
|
|
<D:lockinfo xmlns:D="DAV:">
|
|
<D:lockscope><D:exclusive/></D:lockscope>
|
|
<D:locktype><D:write/></D:locktype>
|
|
<D:owner><D:href>DESKTOP-FRS9AO2\ed</D:href></D:owner>
|
|
</D:lockinfo>"""
|
|
|
|
ref = r"""<?xml version="1.0" encoding="utf-8"?>
|
|
<D:prop xmlns:D="DAV:"><D:lockdiscovery><D:activelock>
|
|
<D:locktype><D:write/></D:locktype>
|
|
<D:lockscope><D:exclusive/></D:lockscope>
|
|
<D:depth>infinity</D:depth>
|
|
<D:owner><D:href>DESKTOP-FRS9AO2\ed</D:href></D:owner>
|
|
<D:timeout>Second-3600</D:timeout>
|
|
<D:locktoken><D:href>1666199679</D:href></D:locktoken>
|
|
<D:lockroot><D:href>/d1/foo.txt</D:href></D:lockroot>
|
|
</D:activelock></D:lockdiscovery></D:prop>"""
|
|
|
|
txt = re.sub("\n +", "\n", txt)
|
|
lk = parse_xml(txt)
|
|
self.assertEqual(lk.tag, "{DAV:}lockinfo")
|
|
|
|
if lk.find(r"./{DAV:}depth") is None:
|
|
lk.append(mktnod("D:depth", "infinity"))
|
|
|
|
lk.append(mkenod("D:timeout", mktnod("D:href", "Second-3600")))
|
|
lk.append(mkenod("D:locktoken", mktnod("D:href", "56709")))
|
|
lk.append(mkenod("D:lockroot", mktnod("D:href", "/foo/bar.txt")))
|
|
|
|
lk2 = mkenod("D:activelock")
|
|
root = mkenod("D:prop", mkenod("D:lockdiscovery", lk2))
|
|
for a in lk:
|
|
lk2.append(a)
|
|
|
|
print(ET.tostring(root).decode("utf-8"))
|