Current File : //lib/calibre/calibre/utils/xml_parse.py
#!/usr/bin/env python3
# License: GPL v3 Copyright: 2019, Kovid Goyal <kovid at kovidgoyal.net>
from lxml import etree
# resolving of SYSTEM entities is turned off as entities can cause
# reads of local files, for example:
# <!DOCTYPE foo [ <!ENTITY passwd SYSTEM "file:///etc/passwd" >]>
fs = etree.fromstring
class Resolver(etree.Resolver):
def resolve(self, url, id, context):
return self.resolve_string('', context)
def create_parser(recover, encoding=None):
parser = etree.XMLParser(recover=recover, no_network=True, encoding=encoding)
parser.resolvers.add(Resolver())
return parser
def safe_xml_fromstring(string_or_bytes, recover=True):
ans = fs(string_or_bytes, parser=create_parser(recover))
if ans is None and recover:
# this happens on windows where if string_or_bytes is unicode and
# contains non-BMP chars lxml chokes
if not isinstance(string_or_bytes, bytes):
string_or_bytes = string_or_bytes.encode('utf-8')
ans = fs(string_or_bytes, parser=create_parser(True, encoding='utf-8'))
if ans is not None:
return ans
ans = fs(string_or_bytes, parser=create_parser(False))
return ans
def find_tests():
import unittest, tempfile, os
from calibre.constants import iswindows
class TestXMLParse(unittest.TestCase):
def setUp(self):
with tempfile.NamedTemporaryFile(delete=False) as tf:
tf.write(b'external')
self.temp_file = os.path.abspath(tf.name)
if iswindows:
from calibre_extensions.winutil import get_long_path_name
self.temp_file = get_long_path_name(self.temp_file)
def tearDown(self):
os.remove(self.temp_file)
def test_safe_xml_fromstring(self):
templ = '''<!DOCTYPE foo [ <!ENTITY e {id} "{val}" > ]><r>&e;</r>'''
external = 'file:///' + self.temp_file.replace(os.sep, '/')
def t(tid, val, expected, safe=True):
raw = templ.format(id=tid, val=val)
err = None
try:
root = safe_xml_fromstring(raw) if safe else etree.fromstring(raw)
except Exception as e:
err = str(e)
root = None
got = getattr(root, 'text', object())
self.assertEqual(got, expected, f'Unexpected result parsing: {raw!r}, got: {got!r} expected: {expected!r} with XML parser error: {err}')
t('SYSTEM', external, 'external', safe=False)
for eid, val, expected in (
('', 'normal entity', 'normal entity'),
('', external, external),
('SYSTEM', external, None),
('SYSTEM', 'http://example.com', None),
('PUBLIC', external, None),
('PUBLIC', 'http://example.com', None),
):
t(eid, val, expected)
def test_lxml_unicode_parsing(self):
from calibre.ebooks.chardet import xml_to_unicode
with open(os.path.join(os.path.dirname(os.path.abspath(__file__)), 'unicode-test.opf'), 'rb') as f:
raw = f.read()
text = xml_to_unicode(raw, strip_encoding_pats=True, resolve_entities=True, assume_utf8=True)[0]
self.assertIsNotNone(safe_xml_fromstring(text))
return unittest.defaultTestLoader.loadTestsFromTestCase(TestXMLParse)
if __name__ == '__main__':
from calibre.utils.run_tests import run_tests
run_tests(find_tests)
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