sslutil: synchronize hostname matching logic with CPython
sslutil contains its own hostname matching logic. CPython has code
for the same intent. However, it is only available to Python 2.7.9+
(or distributions that have backported 2.7.9's ssl module
improvements).
This patch effectively imports CPython's hostname matching code
from its ssl.py into sslutil.py. The hostname matching code itself
is pretty similar. However, the DNS name matching code is much more
robust and spec conformant.
As the test changes show, this changes some behavior around
wildcard handling and IDNA matching. The new behavior allows
wildcards in the middle of words (e.g. 'f*.com' matches 'foo.com')
This is spec compliant according to RFC 6125 Section 6.5.3 item 3.
There is one test where the matcher is more strict. Before,
'*.a.com' matched '.a.com'. Now it doesn't match. Strictly speaking
this is a security vulnerability.
#!/usr/bin/env python
#
# check-py3-compat - check Python 3 compatibility of Mercurial files
#
# Copyright 2015 Gregory Szorc <gregory.szorc@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import, print_function
import ast
import imp
import os
import sys
import traceback
def check_compat_py2(f):
"""Check Python 3 compatibility for a file with Python 2"""
with open(f, 'rb') as fh:
content = fh.read()
root = ast.parse(content)
# Ignore empty files.
if not root.body:
return
futures = set()
haveprint = False
for node in ast.walk(root):
if isinstance(node, ast.ImportFrom):
if node.module == '__future__':
futures |= set(n.name for n in node.names)
elif isinstance(node, ast.Print):
haveprint = True
if 'absolute_import' not in futures:
print('%s not using absolute_import' % f)
if haveprint and 'print_function' not in futures:
print('%s requires print_function' % f)
def check_compat_py3(f):
"""Check Python 3 compatibility of a file with Python 3."""
with open(f, 'rb') as fh:
content = fh.read()
try:
ast.parse(content)
except SyntaxError as e:
print('%s: invalid syntax: %s' % (f, e))
return
# Try to import the module.
# For now we only support mercurial.* and hgext.* modules because figuring
# out module paths for things not in a package can be confusing.
if f.startswith(('hgext/', 'mercurial/')) and not f.endswith('__init__.py'):
assert f.endswith('.py')
name = f.replace('/', '.')[:-3]
with open(f, 'r') as fh:
try:
imp.load_module(name, fh, '', ('py', 'r', imp.PY_SOURCE))
except Exception as e:
exc_type, exc_value, tb = sys.exc_info()
frame = traceback.extract_tb(tb)[-1]
if frame.filename:
filename = os.path.basename(frame.filename)
print('%s: error importing: <%s> %s (error at %s:%d)' % (
f, type(e).__name__, e, filename, frame.lineno))
else:
print('%s: error importing module: <%s> %s (line %d)' % (
f, type(e).__name__, e, frame.lineno))
if __name__ == '__main__':
if sys.version_info[0] == 2:
fn = check_compat_py2
else:
fn = check_compat_py3
for f in sys.argv[1:]:
fn(f)
sys.exit(0)