# sslutil.py - SSL handling for mercurial
#
# Copyright 2005, 2006, 2007, 2008 Matt Mackall <mpm@selenic.com>
# Copyright 2006, 2007 Alexis S. L. Carvalho <alexis@cecm.usp.br>
# Copyright 2006 Vadim Gelfer <vadim.gelfer@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
import os
import ssl
import sys
from .i18n import _
from . import util
_canloaddefaultcerts = False
try:
ssl_context = ssl.SSLContext
_canloaddefaultcerts = util.safehasattr(ssl_context, 'load_default_certs')
def wrapsocket(sock, keyfile, certfile, ui, 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)
sslcontext.options &= ssl.OP_NO_SSLv2 & ssl.OP_NO_SSLv3
if certfile is not None:
def password():
f = keyfile or certfile
return ui.getpass(_('passphrase for %s: ') % f, '')
sslcontext.load_cert_chain(certfile, keyfile, password)
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 wrapsocket(sock, keyfile, certfile, ui, 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
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.
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 = {'ui': ui}
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': ssl.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 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))