sslutil: emit warning when no CA certificates loaded
If no CA certificates are loaded, that is almost certainly a/the
reason certificate verification fails when connecting to a server.
The modern ssl module in Python 2.7.9+ provides an API to access
the list of loaded CA certificates. This patch emits a warning
on modern Python when certificate verification fails and there are
no loaded CA certificates.
There is no way to detect the number of loaded CA certificates
unless the modern ssl module is present. Hence the differences
in test output depending on whether modern ssl is available.
It's worth noting that a test which specifies a CA file still
renders this warning. That is because the certificate it is loading
is a x509 client certificate and not a CA certificate. This
test could be updated if anyone is so inclined.
# mail.py - mail sending bits for mercurial
#
# Copyright 2006 Matt Mackall <mpm@selenic.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, print_function
import email
import os
import quopri
import smtplib
import socket
import sys
import time
from .i18n import _
from . import (
encoding,
error,
sslutil,
util,
)
_oldheaderinit = email.Header.Header.__init__
def _unifiedheaderinit(self, *args, **kw):
"""
Python 2.7 introduces a backwards incompatible change
(Python issue1974, r70772) in email.Generator.Generator code:
pre-2.7 code passed "continuation_ws='\t'" to the Header
constructor, and 2.7 removed this parameter.
Default argument is continuation_ws=' ', which means that the
behavior is different in <2.7 and 2.7
We consider the 2.7 behavior to be preferable, but need
to have an unified behavior for versions 2.4 to 2.7
"""
# override continuation_ws
kw['continuation_ws'] = ' '
_oldheaderinit(self, *args, **kw)
setattr(email.header.Header, '__init__', _unifiedheaderinit)
class STARTTLS(smtplib.SMTP):
'''Derived class to verify the peer certificate for STARTTLS.
This class allows to pass any keyword arguments to SSL socket creation.
'''
def __init__(self, ui, host=None, **kwargs):
smtplib.SMTP.__init__(self, **kwargs)
self._ui = ui
self._host = host
def starttls(self, keyfile=None, certfile=None):
if not self.has_extn("starttls"):
msg = "STARTTLS extension not supported by server"
raise smtplib.SMTPException(msg)
(resp, reply) = self.docmd("STARTTLS")
if resp == 220:
self.sock = sslutil.wrapsocket(self.sock, keyfile, certfile,
ui=self._ui,
serverhostname=self._host)
self.file = smtplib.SSLFakeFile(self.sock)
self.helo_resp = None
self.ehlo_resp = None
self.esmtp_features = {}
self.does_esmtp = 0
return (resp, reply)
class SMTPS(smtplib.SMTP):
'''Derived class to verify the peer certificate for SMTPS.
This class allows to pass any keyword arguments to SSL socket creation.
'''
def __init__(self, ui, keyfile=None, certfile=None, host=None,
**kwargs):
self.keyfile = keyfile
self.certfile = certfile
smtplib.SMTP.__init__(self, **kwargs)
self._host = host
self.default_port = smtplib.SMTP_SSL_PORT
self._ui = ui
def _get_socket(self, host, port, timeout):
if self.debuglevel > 0:
print('connect:', (host, port), file=sys.stderr)
new_socket = socket.create_connection((host, port), timeout)
new_socket = sslutil.wrapsocket(new_socket,
self.keyfile, self.certfile,
ui=self._ui,
serverhostname=self._host)
self.file = smtplib.SSLFakeFile(new_socket)
return new_socket
def _smtp(ui):
'''build an smtp connection and return a function to send mail'''
local_hostname = ui.config('smtp', 'local_hostname')
tls = ui.config('smtp', 'tls', 'none')
# backward compatible: when tls = true, we use starttls.
starttls = tls == 'starttls' or util.parsebool(tls)
smtps = tls == 'smtps'
if (starttls or smtps) and not util.safehasattr(socket, 'ssl'):
raise error.Abort(_("can't use TLS: Python SSL support not installed"))
mailhost = ui.config('smtp', 'host')
if not mailhost:
raise error.Abort(_('smtp.host not configured - cannot send mail'))
if smtps:
ui.note(_('(using smtps)\n'))
s = SMTPS(ui, local_hostname=local_hostname, host=mailhost)
elif starttls:
s = STARTTLS(ui, local_hostname=local_hostname, host=mailhost)
else:
s = smtplib.SMTP(local_hostname=local_hostname)
if smtps:
defaultport = 465
else:
defaultport = 25
mailport = util.getport(ui.config('smtp', 'port', defaultport))
ui.note(_('sending mail: smtp host %s, port %d\n') %
(mailhost, mailport))
s.connect(host=mailhost, port=mailport)
if starttls:
ui.note(_('(using starttls)\n'))
s.ehlo()
s.starttls()
s.ehlo()
if starttls or smtps:
ui.note(_('(verifying remote certificate)\n'))
sslutil.validatesocket(s.sock)
username = ui.config('smtp', 'username')
password = ui.config('smtp', 'password')
if username and not password:
password = ui.getpass()
if username and password:
ui.note(_('(authenticating to mail server as %s)\n') %
(username))
try:
s.login(username, password)
except smtplib.SMTPException as inst:
raise error.Abort(inst)
def send(sender, recipients, msg):
try:
return s.sendmail(sender, recipients, msg)
except smtplib.SMTPRecipientsRefused as inst:
recipients = [r[1] for r in inst.recipients.values()]
raise error.Abort('\n' + '\n'.join(recipients))
except smtplib.SMTPException as inst:
raise error.Abort(inst)
return send
def _sendmail(ui, sender, recipients, msg):
'''send mail using sendmail.'''
program = ui.config('email', 'method', 'smtp')
cmdline = '%s -f %s %s' % (program, util.email(sender),
' '.join(map(util.email, recipients)))
ui.note(_('sending mail: %s\n') % cmdline)
fp = util.popen(cmdline, 'w')
fp.write(msg)
ret = fp.close()
if ret:
raise error.Abort('%s %s' % (
os.path.basename(program.split(None, 1)[0]),
util.explainexit(ret)[0]))
def _mbox(mbox, sender, recipients, msg):
'''write mails to mbox'''
fp = open(mbox, 'ab+')
# Should be time.asctime(), but Windows prints 2-characters day
# of month instead of one. Make them print the same thing.
date = time.strftime('%a %b %d %H:%M:%S %Y', time.localtime())
fp.write('From %s %s\n' % (sender, date))
fp.write(msg)
fp.write('\n\n')
fp.close()
def connect(ui, mbox=None):
'''make a mail connection. return a function to send mail.
call as sendmail(sender, list-of-recipients, msg).'''
if mbox:
open(mbox, 'wb').close()
return lambda s, r, m: _mbox(mbox, s, r, m)
if ui.config('email', 'method', 'smtp') == 'smtp':
return _smtp(ui)
return lambda s, r, m: _sendmail(ui, s, r, m)
def sendmail(ui, sender, recipients, msg, mbox=None):
send = connect(ui, mbox=mbox)
return send(sender, recipients, msg)
def validateconfig(ui):
'''determine if we have enough config data to try sending email.'''
method = ui.config('email', 'method', 'smtp')
if method == 'smtp':
if not ui.config('smtp', 'host'):
raise error.Abort(_('smtp specified as email transport, '
'but no smtp host configured'))
else:
if not util.findexe(method):
raise error.Abort(_('%r specified as email transport, '
'but not in PATH') % method)
def mimetextpatch(s, subtype='plain', display=False):
'''Return MIME message suitable for a patch.
Charset will be detected as utf-8 or (possibly fake) us-ascii.
Transfer encodings will be used if necessary.'''
cs = 'us-ascii'
if not display:
try:
s.decode('us-ascii')
except UnicodeDecodeError:
try:
s.decode('utf-8')
cs = 'utf-8'
except UnicodeDecodeError:
# We'll go with us-ascii as a fallback.
pass
return mimetextqp(s, subtype, cs)
def mimetextqp(body, subtype, charset):
'''Return MIME message.
Quoted-printable transfer encoding will be used if necessary.
'''
enc = None
for line in body.splitlines():
if len(line) > 950:
body = quopri.encodestring(body)
enc = "quoted-printable"
break
msg = email.MIMEText.MIMEText(body, subtype, charset)
if enc:
del msg['Content-Transfer-Encoding']
msg['Content-Transfer-Encoding'] = enc
return msg
def _charsets(ui):
'''Obtains charsets to send mail parts not containing patches.'''
charsets = [cs.lower() for cs in ui.configlist('email', 'charsets')]
fallbacks = [encoding.fallbackencoding.lower(),
encoding.encoding.lower(), 'utf-8']
for cs in fallbacks: # find unique charsets while keeping order
if cs not in charsets:
charsets.append(cs)
return [cs for cs in charsets if not cs.endswith('ascii')]
def _encode(ui, s, charsets):
'''Returns (converted) string, charset tuple.
Finds out best charset by cycling through sendcharsets in descending
order. Tries both encoding and fallbackencoding for input. Only as
last resort send as is in fake ascii.
Caveat: Do not use for mail parts containing patches!'''
try:
s.decode('ascii')
except UnicodeDecodeError:
sendcharsets = charsets or _charsets(ui)
for ics in (encoding.encoding, encoding.fallbackencoding):
try:
u = s.decode(ics)
except UnicodeDecodeError:
continue
for ocs in sendcharsets:
try:
return u.encode(ocs), ocs
except UnicodeEncodeError:
pass
except LookupError:
ui.warn(_('ignoring invalid sendcharset: %s\n') % ocs)
# if ascii, or all conversion attempts fail, send (broken) ascii
return s, 'us-ascii'
def headencode(ui, s, charsets=None, display=False):
'''Returns RFC-2047 compliant header from given string.'''
if not display:
# split into words?
s, cs = _encode(ui, s, charsets)
return str(email.Header.Header(s, cs))
return s
def _addressencode(ui, name, addr, charsets=None):
name = headencode(ui, name, charsets)
try:
acc, dom = addr.split('@')
acc = acc.encode('ascii')
dom = dom.decode(encoding.encoding).encode('idna')
addr = '%s@%s' % (acc, dom)
except UnicodeDecodeError:
raise error.Abort(_('invalid email address: %s') % addr)
except ValueError:
try:
# too strict?
addr = addr.encode('ascii')
except UnicodeDecodeError:
raise error.Abort(_('invalid local address: %s') % addr)
return email.Utils.formataddr((name, addr))
def addressencode(ui, address, charsets=None, display=False):
'''Turns address into RFC-2047 compliant header.'''
if display or not address:
return address or ''
name, addr = email.Utils.parseaddr(address)
return _addressencode(ui, name, addr, charsets)
def addrlistencode(ui, addrs, charsets=None, display=False):
'''Turns a list of addresses into a list of RFC-2047 compliant headers.
A single element of input list may contain multiple addresses, but output
always has one address per item'''
if display:
return [a.strip() for a in addrs if a.strip()]
result = []
for name, addr in email.Utils.getaddresses(addrs):
if name or addr:
result.append(_addressencode(ui, name, addr, charsets))
return result
def mimeencode(ui, s, charsets=None, display=False):
'''creates mime text object, encodes it if needed, and sets
charset and transfer-encoding accordingly.'''
cs = 'us-ascii'
if not display:
s, cs = _encode(ui, s, charsets)
return mimetextqp(s, 'plain', cs)
def headdecode(s):
'''Decodes RFC-2047 header'''
uparts = []
for part, charset in email.Header.decode_header(s):
if charset is not None:
try:
uparts.append(part.decode(charset))
continue
except UnicodeDecodeError:
pass
try:
uparts.append(part.decode('UTF-8'))
continue
except UnicodeDecodeError:
pass
uparts.append(part.decode('ISO-8859-1'))
return encoding.tolocal(u' '.join(uparts).encode('UTF-8'))