view mercurial/pycompat.py @ 29577:9654ef41f7cc

sslutil: support defining cipher list

Python 2.7 supports specifying a custom cipher list to TLS sockets.
Advanced users may wish to specify a custom cipher list to increase
security. Or in some cases they may wish to prefer weaker ciphers
in order to increase performance (e.g. when doing stream clones
of very large repositories).

This patch introduces a [hostsecurity] config option for defining
the cipher list. The help documentation states that it is for
advanced users only.

Honestly, I'm a bit on the fence about providing this because
it is a footgun and can be used to decrease security. However,
there are legitimate use cases for it, so I think support should
be provided.

# pycompat.py - portability shim for python 3
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""Mercurial portability shim for python 3.

This contains aliases to hide python version-specific details from the core.
"""

from __future__ import absolute_import

try:
    import cPickle as pickle
    pickle.dumps
except ImportError:
    import pickle
    pickle.dumps # silence pyflakes

try:
    import httplib
    httplib.HTTPException
except ImportError:
    import http.client as httplib
    httplib.HTTPException

try:
    import SocketServer as socketserver
    socketserver.ThreadingMixIn
except ImportError:
    import socketserver
    socketserver.ThreadingMixIn

try:
    import xmlrpclib
    xmlrpclib.Transport
except ImportError:
    import xmlrpc.client as xmlrpclib
    xmlrpclib.Transport

try:
    import urlparse
    urlparse.urlparse
except ImportError:
    import urllib.parse as urlparse
    urlparse.urlparse

try:
    import cStringIO as io
    stringio = io.StringIO
except ImportError:
    import io
    stringio = io.StringIO

try:
    import Queue as _queue
    _queue.Queue
except ImportError:
    import queue as _queue
empty = _queue.Empty
queue = _queue.Queue

class _pycompatstub(object):
    pass

def _alias(alias, origin, items):
    """ populate a _pycompatstub

    copies items from origin to alias
    """
    def hgcase(item):
        return item.replace('_', '').lower()
    for item in items:
        try:
            setattr(alias, hgcase(item), getattr(origin, item))
        except AttributeError:
            pass

httpserver = _pycompatstub()
urlreq = _pycompatstub()
urlerr = _pycompatstub()
try:
    import BaseHTTPServer
    import CGIHTTPServer
    import SimpleHTTPServer
    import urllib2
    import urllib
    _alias(urlreq, urllib, (
        "addclosehook",
        "addinfourl",
        "ftpwrapper",
        "pathname2url",
        "quote",
        "splitattr",
        "splitpasswd",
        "splitport",
        "splituser",
        "unquote",
        "url2pathname",
        "urlencode",
        "urlencode",
    ))
    _alias(urlreq, urllib2, (
        "AbstractHTTPHandler",
        "BaseHandler",
        "build_opener",
        "FileHandler",
        "FTPHandler",
        "HTTPBasicAuthHandler",
        "HTTPDigestAuthHandler",
        "HTTPHandler",
        "HTTPPasswordMgrWithDefaultRealm",
        "HTTPSHandler",
        "install_opener",
        "ProxyHandler",
        "Request",
        "urlopen",
    ))
    _alias(urlerr, urllib2, (
        "HTTPError",
        "URLError",
    ))
    _alias(httpserver, BaseHTTPServer, (
        "HTTPServer",
        "BaseHTTPRequestHandler",
    ))
    _alias(httpserver, SimpleHTTPServer, (
        "SimpleHTTPRequestHandler",
    ))
    _alias(httpserver, CGIHTTPServer, (
        "CGIHTTPRequestHandler",
    ))

except ImportError:
    import urllib.request
    _alias(urlreq, urllib.request, (
        "AbstractHTTPHandler",
        "addclosehook",
        "addinfourl",
        "BaseHandler",
        "build_opener",
        "FileHandler",
        "FTPHandler",
        "ftpwrapper",
        "HTTPHandler",
        "HTTPSHandler",
        "install_opener",
        "pathname2url",
        "HTTPBasicAuthHandler",
        "HTTPDigestAuthHandler",
        "HTTPPasswordMgrWithDefaultRealm",
        "ProxyHandler",
        "quote",
        "Request",
        "splitattr",
        "splitpasswd",
        "splitport",
        "splituser",
        "unquote",
        "url2pathname",
        "urlopen",
    ))
    import urllib.error
    _alias(urlerr, urllib.error, (
        "HTTPError",
        "URLError",
    ))
    import http.server
    _alias(httpserver, http.server, (
        "HTTPServer",
        "BaseHTTPRequestHandler",
        "SimpleHTTPRequestHandler",
        "CGIHTTPRequestHandler",
    ))

try:
    xrange
except NameError:
    import builtins
    builtins.xrange = range