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# sslutil.py - SSL handling for mercurial
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#
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# Copyright 2005, 2006, 2007, 2008 Matt Mackall <mpm@selenic.com>
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# Copyright 2006, 2007 Alexis S. L. Carvalho <alexis@cecm.usp.br>
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# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>
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#
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# This software may be used and distributed according to the terms of the
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# GNU General Public License version 2 or any later version.
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from __future__ import absolute_import
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import hashlib
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import os
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import re
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import ssl
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from .i18n import _
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from . import (
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error,
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node,
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pycompat,
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util,
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)
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from .utils import (
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stringutil,
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)
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# Python 2.7.9+ overhauled the built-in SSL/TLS features of Python. It added
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# support for TLS 1.1, TLS 1.2, SNI, system CA stores, etc. These features are
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# all exposed via the "ssl" module.
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#
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# Depending on the version of Python being used, SSL/TLS support is either
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# modern/secure or legacy/insecure. Many operations in this module have
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# separate code paths depending on support in Python.
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configprotocols = {
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'tls1.0',
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'tls1.1',
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'tls1.2',
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}
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hassni = getattr(ssl, 'HAS_SNI', False)
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# TLS 1.1 and 1.2 may not be supported if the OpenSSL Python is compiled
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# against doesn't support them.
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supportedprotocols = {'tls1.0'}
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if util.safehasattr(ssl, 'PROTOCOL_TLSv1_1'):
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supportedprotocols.add('tls1.1')
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if util.safehasattr(ssl, 'PROTOCOL_TLSv1_2'):
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supportedprotocols.add('tls1.2')
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try:
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# ssl.SSLContext was added in 2.7.9 and presence indicates modern
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# SSL/TLS features are available.
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SSLContext = ssl.SSLContext
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modernssl = True
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_canloaddefaultcerts = util.safehasattr(SSLContext, 'load_default_certs')
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except AttributeError:
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modernssl = False
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_canloaddefaultcerts = False
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# We implement SSLContext using the interface from the standard library.
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class SSLContext(object):
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def __init__(self, protocol):
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# From the public interface of SSLContext
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self.protocol = protocol
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self.check_hostname = False
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self.options = 0
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self.verify_mode = ssl.CERT_NONE
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# Used by our implementation.
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self._certfile = None
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self._keyfile = None
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self._certpassword = None
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self._cacerts = None
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self._ciphers = None
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def load_cert_chain(self, certfile, keyfile=None, password=None):
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self._certfile = certfile
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self._keyfile = keyfile
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self._certpassword = password
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def load_default_certs(self, purpose=None):
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pass
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def load_verify_locations(self, cafile=None, capath=None, cadata=None):
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if capath:
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raise error.Abort(_('capath not supported'))
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if cadata:
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raise error.Abort(_('cadata not supported'))
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self._cacerts = cafile
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def set_ciphers(self, ciphers):
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self._ciphers = ciphers
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def wrap_socket(self, socket, server_hostname=None, server_side=False):
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# server_hostname is unique to SSLContext.wrap_socket and is used
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# for SNI in that context. So there's nothing for us to do with it
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# in this legacy code since we don't support SNI.
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args = {
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r'keyfile': self._keyfile,
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r'certfile': self._certfile,
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r'server_side': server_side,
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r'cert_reqs': self.verify_mode,
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r'ssl_version': self.protocol,
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r'ca_certs': self._cacerts,
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r'ciphers': self._ciphers,
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}
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return ssl.wrap_socket(socket, **args)
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def _hostsettings(ui, hostname):
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"""Obtain security settings for a hostname.
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Returns a dict of settings relevant to that hostname.
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"""
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bhostname = pycompat.bytesurl(hostname)
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s = {
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# Whether we should attempt to load default/available CA certs
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# if an explicit ``cafile`` is not defined.
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'allowloaddefaultcerts': True,
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# List of 2-tuple of (hash algorithm, hash).
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'certfingerprints': [],
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# Path to file containing concatenated CA certs. Used by
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# SSLContext.load_verify_locations().
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'cafile': None,
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# Whether certificate verification should be disabled.
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'disablecertverification': False,
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# Whether the legacy [hostfingerprints] section has data for this host.
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'legacyfingerprint': False,
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# PROTOCOL_* constant to use for SSLContext.__init__.
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'protocol': None,
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# String representation of minimum protocol to be used for UI
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# presentation.
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'protocolui': None,
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# ssl.CERT_* constant used by SSLContext.verify_mode.
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'verifymode': None,
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# Defines extra ssl.OP* bitwise options to set.
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'ctxoptions': None,
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# OpenSSL Cipher List to use (instead of default).
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'ciphers': None,
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}
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# Allow minimum TLS protocol to be specified in the config.
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def validateprotocol(protocol, key):
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if protocol not in configprotocols:
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raise error.Abort(
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_('unsupported protocol from hostsecurity.%s: %s') %
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(key, protocol),
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hint=_('valid protocols: %s') %
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' '.join(sorted(configprotocols)))
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# We default to TLS 1.1+ where we can because TLS 1.0 has known
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# vulnerabilities (like BEAST and POODLE). We allow users to downgrade to
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# TLS 1.0+ via config options in case a legacy server is encountered.
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if 'tls1.1' in supportedprotocols:
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defaultprotocol = 'tls1.1'
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else:
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# Let people know they are borderline secure.
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# We don't document this config option because we want people to see
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# the bold warnings on the web site.
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# internal config: hostsecurity.disabletls10warning
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if not ui.configbool('hostsecurity', 'disabletls10warning'):
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ui.warn(_('warning: connecting to %s using legacy security '
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'technology (TLS 1.0); see '
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'https://mercurial-scm.org/wiki/SecureConnections for '
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'more info\n') % bhostname)
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defaultprotocol = 'tls1.0'
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key = 'minimumprotocol'
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protocol = ui.config('hostsecurity', key, defaultprotocol)
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validateprotocol(protocol, key)
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key = '%s:minimumprotocol' % bhostname
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protocol = ui.config('hostsecurity', key, protocol)
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validateprotocol(protocol, key)
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# If --insecure is used, we allow the use of TLS 1.0 despite config options.
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# We always print a "connection security to %s is disabled..." message when
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# --insecure is used. So no need to print anything more here.
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if ui.insecureconnections:
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protocol = 'tls1.0'
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s['protocol'], s['ctxoptions'], s['protocolui'] = protocolsettings(protocol)
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ciphers = ui.config('hostsecurity', 'ciphers')
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ciphers = ui.config('hostsecurity', '%s:ciphers' % bhostname, ciphers)
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s['ciphers'] = ciphers
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# Look for fingerprints in [hostsecurity] section. Value is a list
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# of <alg>:<fingerprint> strings.
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fingerprints = ui.configlist('hostsecurity', '%s:fingerprints' % bhostname)
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for fingerprint in fingerprints:
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if not (fingerprint.startswith(('sha1:', 'sha256:', 'sha512:'))):
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raise error.Abort(_('invalid fingerprint for %s: %s') % (
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bhostname, fingerprint),
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hint=_('must begin with "sha1:", "sha256:", '
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'or "sha512:"'))
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alg, fingerprint = fingerprint.split(':', 1)
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fingerprint = fingerprint.replace(':', '').lower()
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s['certfingerprints'].append((alg, fingerprint))
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# Fingerprints from [hostfingerprints] are always SHA-1.
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for fingerprint in ui.configlist('hostfingerprints', bhostname):
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fingerprint = fingerprint.replace(':', '').lower()
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s['certfingerprints'].append(('sha1', fingerprint))
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s['legacyfingerprint'] = True
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# If a host cert fingerprint is defined, it is the only thing that
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# matters. No need to validate CA certs.
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if s['certfingerprints']:
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s['verifymode'] = ssl.CERT_NONE
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s['allowloaddefaultcerts'] = False
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# If --insecure is used, don't take CAs into consideration.
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elif ui.insecureconnections:
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s['disablecertverification'] = True
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s['verifymode'] = ssl.CERT_NONE
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s['allowloaddefaultcerts'] = False
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if ui.configbool('devel', 'disableloaddefaultcerts'):
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s['allowloaddefaultcerts'] = False
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# If both fingerprints and a per-host ca file are specified, issue a warning
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# because users should not be surprised about what security is or isn't
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# being performed.
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cafile = ui.config('hostsecurity', '%s:verifycertsfile' % bhostname)
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if s['certfingerprints'] and cafile:
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ui.warn(_('(hostsecurity.%s:verifycertsfile ignored when host '
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'fingerprints defined; using host fingerprints for '
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'verification)\n') % bhostname)
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# Try to hook up CA certificate validation unless something above
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# makes it not necessary.
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if s['verifymode'] is None:
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# Look at per-host ca file first.
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if cafile:
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cafile = util.expandpath(cafile)
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if not os.path.exists(cafile):
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raise error.Abort(_('path specified by %s does not exist: %s') %
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('hostsecurity.%s:verifycertsfile' % (
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bhostname,), cafile))
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s['cafile'] = cafile
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else:
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# Find global certificates file in config.
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cafile = ui.config('web', 'cacerts')
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if cafile:
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cafile = util.expandpath(cafile)
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if not os.path.exists(cafile):
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raise error.Abort(_('could not find web.cacerts: %s') %
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cafile)
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elif s['allowloaddefaultcerts']:
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# CAs not defined in config. Try to find system bundles.
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cafile = _defaultcacerts(ui)
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if cafile:
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ui.debug('using %s for CA file\n' % cafile)
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s['cafile'] = cafile
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# Require certificate validation if CA certs are being loaded and
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# verification hasn't been disabled above.
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if cafile or (_canloaddefaultcerts and s['allowloaddefaultcerts']):
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s['verifymode'] = ssl.CERT_REQUIRED
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else:
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# At this point we don't have a fingerprint, aren't being
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# explicitly insecure, and can't load CA certs. Connecting
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# is insecure. We allow the connection and abort during
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# validation (once we have the fingerprint to print to the
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# user).
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s['verifymode'] = ssl.CERT_NONE
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assert s['protocol'] is not None
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assert s['ctxoptions'] is not None
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assert s['verifymode'] is not None
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return s
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def protocolsettings(protocol):
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"""Resolve the protocol for a config value.
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Returns a 3-tuple of (protocol, options, ui value) where the first
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2 items are values used by SSLContext and the last is a string value
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of the ``minimumprotocol`` config option equivalent.
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"""
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if protocol not in configprotocols:
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raise ValueError('protocol value not supported: %s' % protocol)
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# Despite its name, PROTOCOL_SSLv23 selects the highest protocol
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# that both ends support, including TLS protocols. On legacy stacks,
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# the highest it likely goes is TLS 1.0. On modern stacks, it can
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# support TLS 1.2.
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#
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# The PROTOCOL_TLSv* constants select a specific TLS version
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# only (as opposed to multiple versions). So the method for
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# supporting multiple TLS versions is to use PROTOCOL_SSLv23 and
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# disable protocols via SSLContext.options and OP_NO_* constants.
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# However, SSLContext.options doesn't work unless we have the
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# full/real SSLContext available to us.
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if supportedprotocols == {'tls1.0'}:
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if protocol != 'tls1.0':
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raise error.Abort(_('current Python does not support protocol '
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'setting %s') % protocol,
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hint=_('upgrade Python or disable setting since '
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'only TLS 1.0 is supported'))
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return ssl.PROTOCOL_TLSv1, 0, 'tls1.0'
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# WARNING: returned options don't work unless the modern ssl module
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# is available. Be careful when adding options here.
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# SSLv2 and SSLv3 are broken. We ban them outright.
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options = ssl.OP_NO_SSLv2 | ssl.OP_NO_SSLv3
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if protocol == 'tls1.0':
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# Defaults above are to use TLS 1.0+
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pass
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elif protocol == 'tls1.1':
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options |= ssl.OP_NO_TLSv1
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elif protocol == 'tls1.2':
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options |= ssl.OP_NO_TLSv1 | ssl.OP_NO_TLSv1_1
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else:
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raise error.Abort(_('this should not happen'))
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# Prevent CRIME.
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# There is no guarantee this attribute is defined on the module.
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options |= getattr(ssl, 'OP_NO_COMPRESSION', 0)
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return ssl.PROTOCOL_SSLv23, options, protocol
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def wrapsocket(sock, keyfile, certfile, ui, serverhostname=None):
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"""Add SSL/TLS to a socket.
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This is a glorified wrapper for ``ssl.wrap_socket()``. It makes sane
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choices based on what security options are available.
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In addition to the arguments supported by ``ssl.wrap_socket``, we allow
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the following additional arguments:
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* serverhostname - The expected hostname of the remote server. If the
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server (and client) support SNI, this tells the server which certificate
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to use.
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"""
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if not serverhostname:
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raise error.Abort(_('serverhostname argument is required'))
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for f in (keyfile, certfile):
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if f and not os.path.exists(f):
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raise error.Abort(
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_('certificate file (%s) does not exist; cannot connect to %s')
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% (f, pycompat.bytesurl(serverhostname)),
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hint=_('restore missing file or fix references '
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'in Mercurial config'))
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settings = _hostsettings(ui, serverhostname)
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# We can't use ssl.create_default_context() because it calls
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# load_default_certs() unless CA arguments are passed to it. We want to
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# have explicit control over CA loading because implicitly loading
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# CAs may undermine the user's intent. For example, a user may define a CA
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# bundle with a specific CA cert removed. If the system/default CA bundle
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# is loaded and contains that removed CA, you've just undone the user's
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# choice.
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sslcontext = SSLContext(settings['protocol'])
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# This is a no-op unless using modern ssl.
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sslcontext.options |= settings['ctxoptions']
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# This still works on our fake SSLContext.
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sslcontext.verify_mode = settings['verifymode']
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if settings['ciphers']:
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try:
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sslcontext.set_ciphers(pycompat.sysstr(settings['ciphers']))
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except ssl.SSLError as e:
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raise error.Abort(
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_('could not set ciphers: %s')
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% stringutil.forcebytestr(e.args[0]),
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hint=_('change cipher string (%s) in config') %
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settings['ciphers'])
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if certfile is not None:
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def password():
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f = keyfile or certfile
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return ui.getpass(_('passphrase for %s: ') % f, '')
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sslcontext.load_cert_chain(certfile, keyfile, password)
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if settings['cafile'] is not None:
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try:
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sslcontext.load_verify_locations(cafile=settings['cafile'])
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except ssl.SSLError as e:
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if len(e.args) == 1: # pypy has different SSLError args
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msg = e.args[0]
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else:
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msg = e.args[1]
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raise error.Abort(_('error loading CA file %s: %s') % (
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settings['cafile'], stringutil.forcebytestr(msg)),
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hint=_('file is empty or malformed?'))
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caloaded = True
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elif settings['allowloaddefaultcerts']:
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# This is a no-op on old Python.
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sslcontext.load_default_certs()
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caloaded = True
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else:
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caloaded = False
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try:
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sslsocket = sslcontext.wrap_socket(sock, server_hostname=serverhostname)
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|
|
except ssl.SSLError as e:
|
|
|
# If we're doing certificate verification and no CA certs are loaded,
|
|
|
# that is almost certainly the reason why verification failed. Provide
|
|
|
# a hint to the user.
|
|
|
# Only modern ssl module exposes SSLContext.get_ca_certs() so we can
|
|
|
# only show this warning if modern ssl is available.
|
|
|
# The exception handler is here to handle bugs around cert attributes:
|
|
|
# https://bugs.python.org/issue20916#msg213479. (See issues5313.)
|
|
|
# When the main 20916 bug occurs, 'sslcontext.get_ca_certs()' is a
|
|
|
# non-empty list, but the following conditional is otherwise True.
|
|
|
try:
|
|
|
if (caloaded and settings['verifymode'] == ssl.CERT_REQUIRED and
|
|
|
modernssl and not sslcontext.get_ca_certs()):
|
|
|
ui.warn(_('(an attempt was made to load CA certificates but '
|
|
|
'none were loaded; see '
|
|
|
'https://mercurial-scm.org/wiki/SecureConnections '
|
|
|
'for how to configure Mercurial to avoid this '
|
|
|
'error)\n'))
|
|
|
except ssl.SSLError:
|
|
|
pass
|
|
|
# Try to print more helpful error messages for known failures.
|
|
|
if util.safehasattr(e, 'reason'):
|
|
|
# This error occurs when the client and server don't share a
|
|
|
# common/supported SSL/TLS protocol. We've disabled SSLv2 and SSLv3
|
|
|
# outright. Hopefully the reason for this error is that we require
|
|
|
# TLS 1.1+ and the server only supports TLS 1.0. Whatever the
|
|
|
# reason, try to emit an actionable warning.
|
|
|
if e.reason == 'UNSUPPORTED_PROTOCOL':
|
|
|
# We attempted TLS 1.0+.
|
|
|
if settings['protocolui'] == 'tls1.0':
|
|
|
# We support more than just TLS 1.0+. If this happens,
|
|
|
# the likely scenario is either the client or the server
|
|
|
# is really old. (e.g. server doesn't support TLS 1.0+ or
|
|
|
# client doesn't support modern TLS versions introduced
|
|
|
# several years from when this comment was written).
|
|
|
if supportedprotocols != {'tls1.0'}:
|
|
|
ui.warn(_(
|
|
|
'(could not communicate with %s using security '
|
|
|
'protocols %s; if you are using a modern Mercurial '
|
|
|
'version, consider contacting the operator of this '
|
|
|
'server; see '
|
|
|
'https://mercurial-scm.org/wiki/SecureConnections '
|
|
|
'for more info)\n') % (
|
|
|
serverhostname,
|
|
|
', '.join(sorted(supportedprotocols))))
|
|
|
else:
|
|
|
ui.warn(_(
|
|
|
'(could not communicate with %s using TLS 1.0; the '
|
|
|
'likely cause of this is the server no longer '
|
|
|
'supports TLS 1.0 because it has known security '
|
|
|
'vulnerabilities; see '
|
|
|
'https://mercurial-scm.org/wiki/SecureConnections '
|
|
|
'for more info)\n') % serverhostname)
|
|
|
else:
|
|
|
# We attempted TLS 1.1+. We can only get here if the client
|
|
|
# supports the configured protocol. So the likely reason is
|
|
|
# the client wants better security than the server can
|
|
|
# offer.
|
|
|
ui.warn(_(
|
|
|
'(could not negotiate a common security protocol (%s+) '
|
|
|
'with %s; the likely cause is Mercurial is configured '
|
|
|
'to be more secure than the server can support)\n') % (
|
|
|
settings['protocolui'], serverhostname))
|
|
|
ui.warn(_('(consider contacting the operator of this '
|
|
|
'server and ask them to support modern TLS '
|
|
|
'protocol versions; or, set '
|
|
|
'hostsecurity.%s:minimumprotocol=tls1.0 to allow '
|
|
|
'use of legacy, less secure protocols when '
|
|
|
'communicating with this server)\n') %
|
|
|
serverhostname)
|
|
|
ui.warn(_(
|
|
|
'(see https://mercurial-scm.org/wiki/SecureConnections '
|
|
|
'for more info)\n'))
|
|
|
|
|
|
elif (e.reason == 'CERTIFICATE_VERIFY_FAILED' and
|
|
|
pycompat.iswindows):
|
|
|
|
|
|
ui.warn(_('(the full certificate chain may not be available '
|
|
|
'locally; see "hg help debugssl")\n'))
|
|
|
raise
|
|
|
|
|
|
# check if wrap_socket failed silently because socket had been
|
|
|
# closed
|
|
|
# - see http://bugs.python.org/issue13721
|
|
|
if not sslsocket.cipher():
|
|
|
raise error.Abort(_('ssl connection failed'))
|
|
|
|
|
|
sslsocket._hgstate = {
|
|
|
'caloaded': caloaded,
|
|
|
'hostname': serverhostname,
|
|
|
'settings': settings,
|
|
|
'ui': ui,
|
|
|
}
|
|
|
|
|
|
return sslsocket
|
|
|
|
|
|
def wrapserversocket(sock, ui, certfile=None, keyfile=None, cafile=None,
|
|
|
requireclientcert=False):
|
|
|
"""Wrap a socket for use by servers.
|
|
|
|
|
|
``certfile`` and ``keyfile`` specify the files containing the certificate's
|
|
|
public and private keys, respectively. Both keys can be defined in the same
|
|
|
file via ``certfile`` (the private key must come first in the file).
|
|
|
|
|
|
``cafile`` defines the path to certificate authorities.
|
|
|
|
|
|
``requireclientcert`` specifies whether to require client certificates.
|
|
|
|
|
|
Typically ``cafile`` is only defined if ``requireclientcert`` is true.
|
|
|
"""
|
|
|
# This function is not used much by core Mercurial, so the error messaging
|
|
|
# doesn't have to be as detailed as for wrapsocket().
|
|
|
for f in (certfile, keyfile, cafile):
|
|
|
if f and not os.path.exists(f):
|
|
|
raise error.Abort(_('referenced certificate file (%s) does not '
|
|
|
'exist') % f)
|
|
|
|
|
|
protocol, options, _protocolui = protocolsettings('tls1.0')
|
|
|
|
|
|
# This config option is intended for use in tests only. It is a giant
|
|
|
# footgun to kill security. Don't define it.
|
|
|
exactprotocol = ui.config('devel', 'serverexactprotocol')
|
|
|
if exactprotocol == 'tls1.0':
|
|
|
protocol = ssl.PROTOCOL_TLSv1
|
|
|
elif exactprotocol == 'tls1.1':
|
|
|
if 'tls1.1' not in supportedprotocols:
|
|
|
raise error.Abort(_('TLS 1.1 not supported by this Python'))
|
|
|
protocol = ssl.PROTOCOL_TLSv1_1
|
|
|
elif exactprotocol == 'tls1.2':
|
|
|
if 'tls1.2' not in supportedprotocols:
|
|
|
raise error.Abort(_('TLS 1.2 not supported by this Python'))
|
|
|
protocol = ssl.PROTOCOL_TLSv1_2
|
|
|
elif exactprotocol:
|
|
|
raise error.Abort(_('invalid value for serverexactprotocol: %s') %
|
|
|
exactprotocol)
|
|
|
|
|
|
if modernssl:
|
|
|
# We /could/ use create_default_context() here since it doesn't load
|
|
|
# CAs when configured for client auth. However, it is hard-coded to
|
|
|
# use ssl.PROTOCOL_SSLv23 which may not be appropriate here.
|
|
|
sslcontext = SSLContext(protocol)
|
|
|
sslcontext.options |= options
|
|
|
|
|
|
# Improve forward secrecy.
|
|
|
sslcontext.options |= getattr(ssl, 'OP_SINGLE_DH_USE', 0)
|
|
|
sslcontext.options |= getattr(ssl, 'OP_SINGLE_ECDH_USE', 0)
|
|
|
|
|
|
# Use the list of more secure ciphers if found in the ssl module.
|
|
|
if util.safehasattr(ssl, '_RESTRICTED_SERVER_CIPHERS'):
|
|
|
sslcontext.options |= getattr(ssl, 'OP_CIPHER_SERVER_PREFERENCE', 0)
|
|
|
sslcontext.set_ciphers(ssl._RESTRICTED_SERVER_CIPHERS)
|
|
|
else:
|
|
|
sslcontext = SSLContext(ssl.PROTOCOL_TLSv1)
|
|
|
|
|
|
if requireclientcert:
|
|
|
sslcontext.verify_mode = ssl.CERT_REQUIRED
|
|
|
else:
|
|
|
sslcontext.verify_mode = ssl.CERT_NONE
|
|
|
|
|
|
if certfile or keyfile:
|
|
|
sslcontext.load_cert_chain(certfile=certfile, keyfile=keyfile)
|
|
|
|
|
|
if cafile:
|
|
|
sslcontext.load_verify_locations(cafile=cafile)
|
|
|
|
|
|
return sslcontext.wrap_socket(sock, server_side=True)
|
|
|
|
|
|
class wildcarderror(Exception):
|
|
|
"""Represents an error parsing wildcards in DNS name."""
|
|
|
|
|
|
def _dnsnamematch(dn, hostname, maxwildcards=1):
|
|
|
"""Match DNS names according RFC 6125 section 6.4.3.
|
|
|
|
|
|
This code is effectively copied from CPython's ssl._dnsname_match.
|
|
|
|
|
|
Returns a bool indicating whether the expected hostname matches
|
|
|
the value in ``dn``.
|
|
|
"""
|
|
|
pats = []
|
|
|
if not dn:
|
|
|
return False
|
|
|
dn = pycompat.bytesurl(dn)
|
|
|
hostname = pycompat.bytesurl(hostname)
|
|
|
|
|
|
pieces = dn.split('.')
|
|
|
leftmost = pieces[0]
|
|
|
remainder = pieces[1:]
|
|
|
wildcards = leftmost.count('*')
|
|
|
if wildcards > maxwildcards:
|
|
|
raise wildcarderror(
|
|
|
_('too many wildcards in certificate DNS name: %s') % dn)
|
|
|
|
|
|
# speed up common case w/o wildcards
|
|
|
if not wildcards:
|
|
|
return dn.lower() == hostname.lower()
|
|
|
|
|
|
# RFC 6125, section 6.4.3, subitem 1.
|
|
|
# The client SHOULD NOT attempt to match a presented identifier in which
|
|
|
# the wildcard character comprises a label other than the left-most label.
|
|
|
if leftmost == '*':
|
|
|
# When '*' is a fragment by itself, it matches a non-empty dotless
|
|
|
# fragment.
|
|
|
pats.append('[^.]+')
|
|
|
elif leftmost.startswith('xn--') or hostname.startswith('xn--'):
|
|
|
# RFC 6125, section 6.4.3, subitem 3.
|
|
|
# The client SHOULD NOT attempt to match a presented identifier
|
|
|
# where the wildcard character is embedded within an A-label or
|
|
|
# U-label of an internationalized domain name.
|
|
|
pats.append(re.escape(leftmost))
|
|
|
else:
|
|
|
# Otherwise, '*' matches any dotless string, e.g. www*
|
|
|
pats.append(re.escape(leftmost).replace(r'\*', '[^.]*'))
|
|
|
|
|
|
# add the remaining fragments, ignore any wildcards
|
|
|
for frag in remainder:
|
|
|
pats.append(re.escape(frag))
|
|
|
|
|
|
pat = re.compile(r'\A' + r'\.'.join(pats) + r'\Z', re.IGNORECASE)
|
|
|
return pat.match(hostname) is not None
|
|
|
|
|
|
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')
|
|
|
|
|
|
dnsnames = []
|
|
|
san = cert.get('subjectAltName', [])
|
|
|
for key, value in san:
|
|
|
if key == 'DNS':
|
|
|
try:
|
|
|
if _dnsnamematch(value, hostname):
|
|
|
return
|
|
|
except wildcarderror as e:
|
|
|
return stringutil.forcebytestr(e.args[0])
|
|
|
|
|
|
dnsnames.append(value)
|
|
|
|
|
|
if not dnsnames:
|
|
|
# The subject is only checked when there is no DNS in subjectAltName.
|
|
|
for sub in cert.get(r'subject', []):
|
|
|
for key, value in sub:
|
|
|
# According to RFC 2818 the most specific Common Name must
|
|
|
# be used.
|
|
|
if key == r'commonName':
|
|
|
# 'subject' entries are unicode.
|
|
|
try:
|
|
|
value = value.encode('ascii')
|
|
|
except UnicodeEncodeError:
|
|
|
return _('IDN in certificate not supported')
|
|
|
|
|
|
try:
|
|
|
if _dnsnamematch(value, hostname):
|
|
|
return
|
|
|
except wildcarderror as e:
|
|
|
return stringutil.forcebytestr(e.args[0])
|
|
|
|
|
|
dnsnames.append(value)
|
|
|
|
|
|
if len(dnsnames) > 1:
|
|
|
return _('certificate is for %s') % ', '.join(dnsnames)
|
|
|
elif len(dnsnames) == 1:
|
|
|
return _('certificate is for %s') % dnsnames[0]
|
|
|
else:
|
|
|
return _('no commonName or subjectAltName found in certificate')
|
|
|
|
|
|
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 (not pycompat.isdarwin or util.mainfrozen() or
|
|
|
not pycompat.sysexecutable):
|
|
|
return False
|
|
|
exe = os.path.realpath(pycompat.sysexecutable).lower()
|
|
|
return (exe.startswith('/usr/bin/python') or
|
|
|
exe.startswith('/system/library/frameworks/python.framework/'))
|
|
|
|
|
|
_systemcacertpaths = [
|
|
|
# RHEL, CentOS, and Fedora
|
|
|
'/etc/pki/tls/certs/ca-bundle.trust.crt',
|
|
|
# Debian, Ubuntu, Gentoo
|
|
|
'/etc/ssl/certs/ca-certificates.crt',
|
|
|
]
|
|
|
|
|
|
def _defaultcacerts(ui):
|
|
|
"""return path to default CA certificates or None.
|
|
|
|
|
|
It is assumed this function is called when the returned certificates
|
|
|
file will actually be used to validate connections. Therefore this
|
|
|
function may print warnings or debug messages assuming this usage.
|
|
|
|
|
|
We don't print a message when the Python is able to load default
|
|
|
CA certs because this scenario is detected at socket connect time.
|
|
|
"""
|
|
|
# The "certifi" Python package provides certificates. If it is installed
|
|
|
# and usable, assume the user intends it to be used and use it.
|
|
|
try:
|
|
|
import certifi
|
|
|
certs = certifi.where()
|
|
|
if os.path.exists(certs):
|
|
|
ui.debug('using ca certificates from certifi\n')
|
|
|
return certs
|
|
|
except (ImportError, AttributeError):
|
|
|
pass
|
|
|
|
|
|
# On Windows, only the modern ssl module is capable of loading the system
|
|
|
# CA certificates. If we're not capable of doing that, emit a warning
|
|
|
# because we'll get a certificate verification error later and the lack
|
|
|
# of loaded CA certificates will be the reason why.
|
|
|
# Assertion: this code is only called if certificates are being verified.
|
|
|
if pycompat.iswindows:
|
|
|
if not _canloaddefaultcerts:
|
|
|
ui.warn(_('(unable to load Windows CA certificates; see '
|
|
|
'https://mercurial-scm.org/wiki/SecureConnections for '
|
|
|
'how to configure Mercurial to avoid this message)\n'))
|
|
|
|
|
|
return None
|
|
|
|
|
|
# Apple's OpenSSL has patches that allow a specially constructed certificate
|
|
|
# to load the system CA store. If we're running on Apple Python, use this
|
|
|
# trick.
|
|
|
if _plainapplepython():
|
|
|
dummycert = os.path.join(
|
|
|
os.path.dirname(pycompat.fsencode(__file__)), 'dummycert.pem')
|
|
|
if os.path.exists(dummycert):
|
|
|
return dummycert
|
|
|
|
|
|
# The Apple OpenSSL trick isn't available to us. If Python isn't able to
|
|
|
# load system certs, we're out of luck.
|
|
|
if pycompat.isdarwin:
|
|
|
# FUTURE Consider looking for Homebrew or MacPorts installed certs
|
|
|
# files. Also consider exporting the keychain certs to a file during
|
|
|
# Mercurial install.
|
|
|
if not _canloaddefaultcerts:
|
|
|
ui.warn(_('(unable to load CA certificates; see '
|
|
|
'https://mercurial-scm.org/wiki/SecureConnections for '
|
|
|
'how to configure Mercurial to avoid this message)\n'))
|
|
|
return None
|
|
|
|
|
|
# / is writable on Windows. Out of an abundance of caution make sure
|
|
|
# we're not on Windows because paths from _systemcacerts could be installed
|
|
|
# by non-admin users.
|
|
|
assert not pycompat.iswindows
|
|
|
|
|
|
# Try to find CA certificates in well-known locations. We print a warning
|
|
|
# when using a found file because we don't want too much silent magic
|
|
|
# for security settings. The expectation is that proper Mercurial
|
|
|
# installs will have the CA certs path defined at install time and the
|
|
|
# installer/packager will make an appropriate decision on the user's
|
|
|
# behalf. We only get here and perform this setting as a feature of
|
|
|
# last resort.
|
|
|
if not _canloaddefaultcerts:
|
|
|
for path in _systemcacertpaths:
|
|
|
if os.path.isfile(path):
|
|
|
ui.warn(_('(using CA certificates from %s; if you see this '
|
|
|
'message, your Mercurial install is not properly '
|
|
|
'configured; see '
|
|
|
'https://mercurial-scm.org/wiki/SecureConnections '
|
|
|
'for how to configure Mercurial to avoid this '
|
|
|
'message)\n') % path)
|
|
|
return path
|
|
|
|
|
|
ui.warn(_('(unable to load CA certificates; see '
|
|
|
'https://mercurial-scm.org/wiki/SecureConnections for '
|
|
|
'how to configure Mercurial to avoid this message)\n'))
|
|
|
|
|
|
return None
|
|
|
|
|
|
def validatesocket(sock):
|
|
|
"""Validate a socket meets security requirements.
|
|
|
|
|
|
The passed socket must have been created with ``wrapsocket()``.
|
|
|
"""
|
|
|
shost = sock._hgstate['hostname']
|
|
|
host = pycompat.bytesurl(shost)
|
|
|
ui = sock._hgstate['ui']
|
|
|
settings = sock._hgstate['settings']
|
|
|
|
|
|
try:
|
|
|
peercert = sock.getpeercert(True)
|
|
|
peercert2 = sock.getpeercert()
|
|
|
except AttributeError:
|
|
|
raise error.Abort(_('%s ssl connection error') % host)
|
|
|
|
|
|
if not peercert:
|
|
|
raise error.Abort(_('%s certificate error: '
|
|
|
'no certificate received') % host)
|
|
|
|
|
|
if settings['disablecertverification']:
|
|
|
# We don't print the certificate fingerprint because it shouldn't
|
|
|
# be necessary: if the user requested certificate verification be
|
|
|
# disabled, they presumably already saw a message about the inability
|
|
|
# to verify the certificate and this message would have printed the
|
|
|
# fingerprint. So printing the fingerprint here adds little to no
|
|
|
# value.
|
|
|
ui.warn(_('warning: connection security to %s is disabled per current '
|
|
|
'settings; communication is susceptible to eavesdropping '
|
|
|
'and tampering\n') % host)
|
|
|
return
|
|
|
|
|
|
# If a certificate fingerprint is pinned, use it and only it to
|
|
|
# validate the remote cert.
|
|
|
peerfingerprints = {
|
|
|
'sha1': node.hex(hashlib.sha1(peercert).digest()),
|
|
|
'sha256': node.hex(hashlib.sha256(peercert).digest()),
|
|
|
'sha512': node.hex(hashlib.sha512(peercert).digest()),
|
|
|
}
|
|
|
|
|
|
def fmtfingerprint(s):
|
|
|
return ':'.join([s[x:x + 2] for x in range(0, len(s), 2)])
|
|
|
|
|
|
nicefingerprint = 'sha256:%s' % fmtfingerprint(peerfingerprints['sha256'])
|
|
|
|
|
|
if settings['certfingerprints']:
|
|
|
for hash, fingerprint in settings['certfingerprints']:
|
|
|
if peerfingerprints[hash].lower() == fingerprint:
|
|
|
ui.debug('%s certificate matched fingerprint %s:%s\n' %
|
|
|
(host, hash, fmtfingerprint(fingerprint)))
|
|
|
if settings['legacyfingerprint']:
|
|
|
ui.warn(_('(SHA-1 fingerprint for %s found in legacy '
|
|
|
'[hostfingerprints] section; '
|
|
|
'if you trust this fingerprint, remove the old '
|
|
|
'SHA-1 fingerprint from [hostfingerprints] and '
|
|
|
'add the following entry to the new '
|
|
|
'[hostsecurity] section: %s:fingerprints=%s)\n') %
|
|
|
(host, host, nicefingerprint))
|
|
|
return
|
|
|
|
|
|
# Pinned fingerprint didn't match. This is a fatal error.
|
|
|
if settings['legacyfingerprint']:
|
|
|
section = 'hostfingerprint'
|
|
|
nice = fmtfingerprint(peerfingerprints['sha1'])
|
|
|
else:
|
|
|
section = 'hostsecurity'
|
|
|
nice = '%s:%s' % (hash, fmtfingerprint(peerfingerprints[hash]))
|
|
|
raise error.Abort(_('certificate for %s has unexpected '
|
|
|
'fingerprint %s') % (host, nice),
|
|
|
hint=_('check %s configuration') % section)
|
|
|
|
|
|
# Security is enabled but no CAs are loaded. We can't establish trust
|
|
|
# for the cert so abort.
|
|
|
if not sock._hgstate['caloaded']:
|
|
|
raise error.Abort(
|
|
|
_('unable to verify security of %s (no loaded CA certificates); '
|
|
|
'refusing to connect') % host,
|
|
|
hint=_('see https://mercurial-scm.org/wiki/SecureConnections for '
|
|
|
'how to configure Mercurial to avoid this error or set '
|
|
|
'hostsecurity.%s:fingerprints=%s to trust this server') %
|
|
|
(host, nicefingerprint))
|
|
|
|
|
|
msg = _verifycert(peercert2, shost)
|
|
|
if msg:
|
|
|
raise error.Abort(_('%s certificate error: %s') % (host, msg),
|
|
|
hint=_('set hostsecurity.%s:certfingerprints=%s '
|
|
|
'config setting or use --insecure to connect '
|
|
|
'insecurely') %
|
|
|
(host, nicefingerprint))
|
|
|
|