I've recently started working with Bitbucket and mercurial. I can work with git repositories just fine, but when I try to clone a mercurial one, it crashes in /Users/foobar/Library/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/mercurial-3.4.2-py2.7-macosx-10.6-x86_64.egg/mercurial/sslutil.py on line 36, with the error:
ValueError: can't clear options before OpenSSL 0.9.8m
I am running OpenSSL 1.0.2c.
As is apparent from the file path, I downloaded python (and mercurial) through Enthought Canopy
I searched around and I found someone with a similar problem: https://bitbucket.org/durin42/hgsubversion/issues/439/unknown-exception-in-dispatchpy-value. His partial solution (commenting out the offending line) was enough to make my download work, but I confess I am out of my depth in trying to determine whether this will cause any security issues with me using Mercurial. Are there any potential security issues with this? Is there any additional information you'd need to begin to answer this?
The file I edited is below (search for "==========" to find the line I removed).
# sslutil.py - SSL handling for mercurial
#
# Copyright 2005, 2006, 2007, 2008 Matt Mackall <[email protected]>
# Copyright 2006, 2007 Alexis S. L. Carvalho <[email protected]>
# Copyright 2006 Vadim Gelfer <[email protected]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
import os, sys
from mercurial import util
from mercurial.i18n import _
_canloaddefaultcerts = False
try:
# avoid using deprecated/broken FakeSocket in python 2.6
import ssl
CERT_REQUIRED = ssl.CERT_REQUIRED
try:
ssl_context = ssl.SSLContext
_canloaddefaultcerts = util.safehasattr(ssl_context,
'load_default_certs')
def ssl_wrap_socket(sock, keyfile, certfile, cert_reqs=ssl.CERT_NONE,
ca_certs=None, serverhostname=None):
# Allow any version of SSL starting with TLSv1 and
# up. Note that specifying TLSv1 here prohibits use of
# newer standards (like TLSv1_2), so this is the right way
# to do this. Note that in the future it'd be better to
# support using ssl.create_default_context(), which sets
# up a bunch of things in smart ways (strong ciphers,
# protocol versions, etc) and is upgraded by Python
# maintainers for us, but that breaks too many things to
# do it in a hurry.
sslcontext = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
# ================================================
# LINE I REMOVED
sslcontext.options &= ssl.OP_NO_SSLv2 & ssl.OP_NO_SSLv3
# ================================================
if certfile is not None:
sslcontext.load_cert_chain(certfile, keyfile)
sslcontext.verify_mode = cert_reqs
if ca_certs is not None:
sslcontext.load_verify_locations(cafile=ca_certs)
elif _canloaddefaultcerts:
sslcontext.load_default_certs()
sslsocket = sslcontext.wrap_socket(sock,
server_hostname=serverhostname)
# check if wrap_socket failed silently because socket had been
# closed
# - see http://bugs.python.org/issue13721
if not sslsocket.cipher():
raise util.Abort(_('ssl connection failed'))
return sslsocket
except AttributeError:
def ssl_wrap_socket(sock, keyfile, certfile, cert_reqs=ssl.CERT_NONE,
ca_certs=None, serverhostname=None):
sslsocket = ssl.wrap_socket(sock, keyfile, certfile,
cert_reqs=cert_reqs, ca_certs=ca_certs,
ssl_version=ssl.PROTOCOL_TLSv1)
# check if wrap_socket failed silently because socket had been
# closed
# - see http://bugs.python.org/issue13721
if not sslsocket.cipher():
raise util.Abort(_('ssl connection failed'))
return sslsocket
except ImportError:
CERT_REQUIRED = 2
import socket, httplib
def ssl_wrap_socket(sock, keyfile, certfile, cert_reqs=CERT_REQUIRED,
ca_certs=None, serverhostname=None):
if not util.safehasattr(socket, 'ssl'):
raise util.Abort(_('Python SSL support not found'))
if ca_certs:
raise util.Abort(_(
'certificate checking requires Python 2.6'))
ssl = socket.ssl(sock, keyfile, certfile)
return httplib.FakeSocket(sock, ssl)
def _verifycert(cert, hostname):
'''Verify that cert (in socket.getpeercert() format) matches hostname.
CRLs is not handled.
Returns error message if any problems are found and None on success.
'''
if not cert:
return _('no certificate received')
dnsname = hostname.lower()
def matchdnsname(certname):
return (certname == dnsname or
'.' in dnsname and certname == '*.' + dnsname.split('.', 1)[1])
san = cert.get('subjectAltName', [])
if san:
certnames = [value.lower() for key, value in san if key == 'DNS']
for name in certnames:
if matchdnsname(name):
return None
if certnames:
return _('certificate is for %s') % ', '.join(certnames)
# subject is only checked when subjectAltName is empty
for s in cert.get('subject', []):
key, value = s[0]
if key == 'commonName':
try:
# 'subject' entries are unicode
certname = value.lower().encode('ascii')
except UnicodeEncodeError:
return _('IDN in certificate not supported')
if matchdnsname(certname):
return None
return _('certificate is for %s') % certname
return _('no commonName or subjectAltName found in certificate')
# CERT_REQUIRED means fetch the cert from the server all the time AND
# validate it against the CA store provided in web.cacerts.
#
# We COMPLETELY ignore CERT_REQUIRED on Python <= 2.5, as it's totally
# busted on those versions.
def _plainapplepython():
"""return true if this seems to be a pure Apple Python that
* is unfrozen and presumably has the whole mercurial module in the file
system
* presumably is an Apple Python that uses Apple OpenSSL which has patches
for using system certificate store CAs in addition to the provided
cacerts file
"""
if sys.platform != 'darwin' or util.mainfrozen() or not sys.executable:
return False
exe = os.path.realpath(sys.executable).lower()
return (exe.startswith('/usr/bin/python') or
exe.startswith('/system/library/frameworks/python.framework/'))
def _defaultcacerts():
"""return path to CA certificates; None for system's store; ! to disable"""
if _plainapplepython():
dummycert = os.path.join(os.path.dirname(__file__), 'dummycert.pem')
if os.path.exists(dummycert):
return dummycert
if _canloaddefaultcerts:
return None
return '!'
def sslkwargs(ui, host):
kws = {}
hostfingerprint = ui.config('hostfingerprints', host)
if hostfingerprint:
return kws
cacerts = ui.config('web', 'cacerts')
if cacerts == '!':
pass
elif cacerts:
cacerts = util.expandpath(cacerts)
if not os.path.exists(cacerts):
raise util.Abort(_('could not find web.cacerts: %s') % cacerts)
else:
cacerts = _defaultcacerts()
if cacerts and cacerts != '!':
ui.debug('using %s to enable OS X system CA\n' % cacerts)
ui.setconfig('web', 'cacerts', cacerts, 'defaultcacerts')
if cacerts != '!':
kws.update({'ca_certs': cacerts,
'cert_reqs': CERT_REQUIRED,
})
return kws
class validator(object):
def __init__(self, ui, host):
self.ui = ui
self.host = host
def __call__(self, sock, strict=False):
host = self.host
cacerts = self.ui.config('web', 'cacerts')
hostfingerprint = self.ui.config('hostfingerprints', host)
if not getattr(sock, 'getpeercert', False): # python 2.5 ?
if hostfingerprint:
raise util.Abort(_("host fingerprint for %s can't be "
"verified (Python too old)") % host)
if strict:
raise util.Abort(_("certificate for %s can't be verified "
"(Python too old)") % host)
if self.ui.configbool('ui', 'reportoldssl', True):
self.ui.warn(_("warning: certificate for %s can't be verified "
"(Python too old)\n") % host)
return
if not sock.cipher(): # work around http://bugs.python.org/issue13721
raise util.Abort(_('%s ssl connection error') % host)
try:
peercert = sock.getpeercert(True)
peercert2 = sock.getpeercert()
except AttributeError:
raise util.Abort(_('%s ssl connection error') % host)
if not peercert:
raise util.Abort(_('%s certificate error: '
'no certificate received') % host)
peerfingerprint = util.sha1(peercert).hexdigest()
nicefingerprint = ":".join([peerfingerprint[x:x + 2]
for x in xrange(0, len(peerfingerprint), 2)])
if hostfingerprint:
if peerfingerprint.lower() != \
hostfingerprint.replace(':', '').lower():
raise util.Abort(_('certificate for %s has unexpected '
'fingerprint %s') % (host, nicefingerprint),
hint=_('check hostfingerprint configuration'))
self.ui.debug('%s certificate matched fingerprint %s\n' %
(host, nicefingerprint))
elif cacerts != '!':
msg = _verifycert(peercert2, host)
if msg:
raise util.Abort(_('%s certificate error: %s') % (host, msg),
hint=_('configure hostfingerprint %s or use '
'--insecure to connect insecurely') %
nicefingerprint)
self.ui.debug('%s certificate successfully verified\n' % host)
elif strict:
raise util.Abort(_('%s certificate with fingerprint %s not '
'verified') % (host, nicefingerprint),
hint=_('check hostfingerprints or web.cacerts '
'config setting'))
else:
self.ui.warn(_('warning: %s certificate with fingerprint %s not '
'verified (check hostfingerprints or web.cacerts '
'config setting)\n') %
(host, nicefingerprint))
