view mercurial/pycompat.py @ 29334:ecc9b788fd69

sslutil: per-host config option to define certificates

Recent work has introduced the [hostsecurity] config section for
defining per-host security settings. This patch builds on top
of this foundation and implements the ability to define a per-host
path to a file containing certificates used for verifying the server
certificate. It is logically a per-host web.cacerts setting.

This patch also introduces a warning when both per-host
certificates and fingerprints are defined. These are mutually
exclusive for host verification and I think the user should be
alerted when security settings are ambiguous because, well,
security is important.

Tests validating the new behavior have been added.

I decided against putting "ca" in the option name because a
non-CA certificate can be specified and used to validate the server
certificate (commonly this will be the exact public certificate
used by the server). It's worth noting that the underlying
Python API used is load_verify_locations(cafile=X) and it calls
into OpenSSL's SSL_CTX_load_verify_locations(). Even OpenSSL's
documentation seems to omit that the file can contain a non-CA
certificate if it matches the server's certificate exactly. I
thought a CA certificate was a special kind of x509 certificate.
Perhaps I'm wrong and any x509 certificate can be used as a
CA certificate [as far as OpenSSL is concerned]. In any case,
I thought it best to drop "ca" from the name because this reflects
reality.

# 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

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

urlreq = _pycompatstub()
urlerr = _pycompatstub()
try:
    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",
    ))

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",
        "ProxyHandler",
        "quote",
        "Request",
        "splitattr",
        "splitpasswd",
        "splitport",
        "splituser",
        "unquote",
        "url2pathname",
        "urlopen",
    ))
    import urllib.error
    _alias(urlerr, urllib.error, (
        "HTTPError",
        "URLError",
    ))

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