sslutil: abort when unable to verify peer connection (BC)
Previously, when we connected to a server and were unable to verify
its certificate against a trusted certificate authority we would
issue a warning and continue to connect. This is obviously not
great behavior because the x509 certificate model is based upon
trust of specific CAs. Failure to enforce that trust erodes security.
This behavior was defined several years ago when Python did not
support loading the system trusted CA store (Python 2.7.9's
backports of Python 3's improvements to the "ssl" module enabled
this).
This commit changes behavior when connecting to abort if the peer
certificate can't be validated. With an empty/default Mercurial
configuration, the peer certificate can be validated if Python is
able to load the system trusted CA store. Environments able to load
the system trusted CA store include:
* Python 2.7.9+ on most platforms and installations
* Python 2.7 distributions with a modern ssl module (e.g. RHEL7's
patched 2.7.5 package)
* Python shipped on OS X
Environments unable to load the system trusted CA store include:
* Python 2.6
* Python 2.7 on many existing Linux installs (because they don't
ship 2.7.9+ or haven't backported modern ssl module)
* Python 2.7.9+ on some installs where Python is unable to locate
the system CA store (this is hopefully rare)
Users of these Pythongs will need to configure Mercurial to load the
system CA store using web.cacerts. This should ideally be performed
by packagers (by setting web.cacerts in the global/system hgrc file).
Where Mercurial packagers aren't setting this, the linked URL in the
new abort message can contain instructions for users.
In the future, we may want to add more code for finding the system
CA store. For example, many Linux distributions have the CA store
at well-known locations (such as /etc/ssl/certs/ca-certificates.crt
in the case of Ubuntu). This will enable CA loading to "just work"
on more Python configurations and will be best for our users since
they won't have to change anything after upgrading to a Mercurial
with this patch.
We may also want to consider distributing a trusted CA store with
Mercurial. Although we should think long and hard about that because
most systems have a global CA store and Mercurial should almost
certainly use the same store used by everything else on the system.
# Copyright 2009, Alexander Solovyov <piranha@piranha.org.ua>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""extend schemes with shortcuts to repository swarms
This extension allows you to specify shortcuts for parent URLs with a
lot of repositories to act like a scheme, for example::
[schemes]
py = http://code.python.org/hg/
After that you can use it like::
hg clone py://trunk/
Additionally there is support for some more complex schemas, for
example used by Google Code::
[schemes]
gcode = http://{1}.googlecode.com/hg/
The syntax is taken from Mercurial templates, and you have unlimited
number of variables, starting with ``{1}`` and continuing with
``{2}``, ``{3}`` and so on. This variables will receive parts of URL
supplied, split by ``/``. Anything not specified as ``{part}`` will be
just appended to an URL.
For convenience, the extension adds these schemes by default::
[schemes]
py = http://hg.python.org/
bb = https://bitbucket.org/
bb+ssh = ssh://hg@bitbucket.org/
gcode = https://{1}.googlecode.com/hg/
kiln = https://{1}.kilnhg.com/Repo/
You can override a predefined scheme by defining a new scheme with the
same name.
"""
from __future__ import absolute_import
import os
import re
from mercurial.i18n import _
from mercurial import (
cmdutil,
error,
extensions,
hg,
templater,
util,
)
cmdtable = {}
command = cmdutil.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'internal' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'internal'
class ShortRepository(object):
def __init__(self, url, scheme, templater):
self.scheme = scheme
self.templater = templater
self.url = url
try:
self.parts = max(map(int, re.findall(r'\{(\d+)\}', self.url)))
except ValueError:
self.parts = 0
def __repr__(self):
return '<ShortRepository: %s>' % self.scheme
def instance(self, ui, url, create):
url = self.resolve(url)
return hg._peerlookup(url).instance(ui, url, create)
def resolve(self, url):
# Should this use the util.url class, or is manual parsing better?
try:
url = url.split('://', 1)[1]
except IndexError:
raise error.Abort(_("no '://' in scheme url '%s'") % url)
parts = url.split('/', self.parts)
if len(parts) > self.parts:
tail = parts[-1]
parts = parts[:-1]
else:
tail = ''
context = dict((str(i + 1), v) for i, v in enumerate(parts))
return ''.join(self.templater.process(self.url, context)) + tail
def hasdriveletter(orig, path):
if path:
for scheme in schemes:
if path.startswith(scheme + ':'):
return False
return orig(path)
schemes = {
'py': 'http://hg.python.org/',
'bb': 'https://bitbucket.org/',
'bb+ssh': 'ssh://hg@bitbucket.org/',
'gcode': 'https://{1}.googlecode.com/hg/',
'kiln': 'https://{1}.kilnhg.com/Repo/'
}
def extsetup(ui):
schemes.update(dict(ui.configitems('schemes')))
t = templater.engine(lambda x: x)
for scheme, url in schemes.items():
if (os.name == 'nt' and len(scheme) == 1 and scheme.isalpha()
and os.path.exists('%s:\\' % scheme)):
raise error.Abort(_('custom scheme %s:// conflicts with drive '
'letter %s:\\\n') % (scheme, scheme.upper()))
hg.schemes[scheme] = ShortRepository(url, scheme, t)
extensions.wrapfunction(util, 'hasdriveletter', hasdriveletter)
@command('debugexpandscheme', norepo=True)
def expandscheme(ui, url, **opts):
"""given a repo path, provide the scheme-expanded path
"""
repo = hg._peerlookup(url)
if isinstance(repo, ShortRepository):
url = repo.resolve(url)
ui.write(url + '\n')