Add a setting to disable TLS for sending email (#10546)

This is mostly useful in case the server offers TLS, but doesn't present a valid certificate.
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Richard van der Hoff 2021-08-06 11:13:34 +01:00 committed by GitHub
parent f5a368bb48
commit 74d7336686
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8 changed files with 138 additions and 50 deletions

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@ -0,0 +1 @@
Add a setting to disable TLS when sending email.

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@ -2242,6 +2242,14 @@ email:
#
#require_transport_security: true
# Uncomment the following to disable TLS for SMTP.
#
# By default, if the server supports TLS, it will be used, and the server
# must present a certificate that is valid for 'smtp_host'. If this option
# is set to false, TLS will not be used.
#
#enable_tls: false
# notif_from defines the "From" address to use when sending emails.
# It must be set if email sending is enabled.
#

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@ -80,6 +80,12 @@ class EmailConfig(Config):
self.require_transport_security = email_config.get(
"require_transport_security", False
)
self.enable_smtp_tls = email_config.get("enable_tls", True)
if self.require_transport_security and not self.enable_smtp_tls:
raise ConfigError(
"email.require_transport_security requires email.enable_tls to be true"
)
if "app_name" in email_config:
self.email_app_name = email_config["app_name"]
else:
@ -368,6 +374,14 @@ class EmailConfig(Config):
#
#require_transport_security: true
# Uncomment the following to disable TLS for SMTP.
#
# By default, if the server supports TLS, it will be used, and the server
# must present a certificate that is valid for 'smtp_host'. If this option
# is set to false, TLS will not be used.
#
#enable_tls: false
# notif_from defines the "From" address to use when sending emails.
# It must be set if email sending is enabled.
#

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@ -16,7 +16,12 @@ import email.utils
import logging
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from typing import TYPE_CHECKING
from io import BytesIO
from typing import TYPE_CHECKING, Optional
from twisted.internet.defer import Deferred
from twisted.internet.interfaces import IReactorTCP
from twisted.mail.smtp import ESMTPSenderFactory
from synapse.logging.context import make_deferred_yieldable
@ -26,19 +31,75 @@ if TYPE_CHECKING:
logger = logging.getLogger(__name__)
async def _sendmail(
reactor: IReactorTCP,
smtphost: str,
smtpport: int,
from_addr: str,
to_addr: str,
msg_bytes: bytes,
username: Optional[bytes] = None,
password: Optional[bytes] = None,
require_auth: bool = False,
require_tls: bool = False,
tls_hostname: Optional[str] = None,
) -> None:
"""A simple wrapper around ESMTPSenderFactory, to allow substitution in tests
Params:
reactor: reactor to use to make the outbound connection
smtphost: hostname to connect to
smtpport: port to connect to
from_addr: "From" address for email
to_addr: "To" address for email
msg_bytes: Message content
username: username to authenticate with, if auth is enabled
password: password to give when authenticating
require_auth: if auth is not offered, fail the request
require_tls: if TLS is not offered, fail the reqest
tls_hostname: TLS hostname to check for. None to disable TLS.
"""
msg = BytesIO(msg_bytes)
d: "Deferred[object]" = Deferred()
factory = ESMTPSenderFactory(
username,
password,
from_addr,
to_addr,
msg,
d,
heloFallback=True,
requireAuthentication=require_auth,
requireTransportSecurity=require_tls,
hostname=tls_hostname,
)
# the IReactorTCP interface claims host has to be a bytes, which seems to be wrong
reactor.connectTCP(smtphost, smtpport, factory, timeout=30, bindAddress=None) # type: ignore[arg-type]
await make_deferred_yieldable(d)
class SendEmailHandler:
def __init__(self, hs: "HomeServer"):
self.hs = hs
self._sendmail = hs.get_sendmail()
self._reactor = hs.get_reactor()
self._from = hs.config.email.email_notif_from
self._smtp_host = hs.config.email.email_smtp_host
self._smtp_port = hs.config.email.email_smtp_port
self._smtp_user = hs.config.email.email_smtp_user
self._smtp_pass = hs.config.email.email_smtp_pass
user = hs.config.email.email_smtp_user
self._smtp_user = user.encode("utf-8") if user is not None else None
passwd = hs.config.email.email_smtp_pass
self._smtp_pass = passwd.encode("utf-8") if passwd is not None else None
self._require_transport_security = hs.config.email.require_transport_security
self._enable_tls = hs.config.email.enable_smtp_tls
self._sendmail = _sendmail
async def send_email(
self,
@ -82,17 +143,16 @@ class SendEmailHandler:
logger.info("Sending email to %s" % email_address)
await make_deferred_yieldable(
self._sendmail(
self._smtp_host,
raw_from,
raw_to,
multipart_msg.as_string().encode("utf8"),
reactor=self._reactor,
port=self._smtp_port,
requireAuthentication=self._smtp_user is not None,
username=self._smtp_user,
password=self._smtp_pass,
requireTransportSecurity=self._require_transport_security,
)
await self._sendmail(
self._reactor,
self._smtp_host,
self._smtp_port,
raw_from,
raw_to,
multipart_msg.as_string().encode("utf8"),
username=self._smtp_user,
password=self._smtp_pass,
require_auth=self._smtp_user is not None,
require_tls=self._require_transport_security,
tls_hostname=self._smtp_host if self._enable_tls else None,
)

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@ -34,8 +34,6 @@ from typing import (
)
import twisted.internet.tcp
from twisted.internet import defer
from twisted.mail.smtp import sendmail
from twisted.web.iweb import IPolicyForHTTPS
from twisted.web.resource import IResource
@ -442,10 +440,6 @@ class HomeServer(metaclass=abc.ABCMeta):
def get_room_shutdown_handler(self) -> RoomShutdownHandler:
return RoomShutdownHandler(self)
@cache_in_self
def get_sendmail(self) -> Callable[..., defer.Deferred]:
return sendmail
@cache_in_self
def get_state_handler(self) -> StateHandler:
return StateHandler(self)

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@ -45,14 +45,6 @@ class EmailPusherTests(HomeserverTestCase):
def make_homeserver(self, reactor, clock):
# List[Tuple[Deferred, args, kwargs]]
self.email_attempts = []
def sendmail(*args, **kwargs):
d = Deferred()
self.email_attempts.append((d, args, kwargs))
return d
config = self.default_config()
config["email"] = {
"enable_notifs": True,
@ -75,7 +67,17 @@ class EmailPusherTests(HomeserverTestCase):
config["public_baseurl"] = "aaa"
config["start_pushers"] = True
hs = self.setup_test_homeserver(config=config, sendmail=sendmail)
hs = self.setup_test_homeserver(config=config)
# List[Tuple[Deferred, args, kwargs]]
self.email_attempts = []
def sendmail(*args, **kwargs):
d = Deferred()
self.email_attempts.append((d, args, kwargs))
return d
hs.get_send_email_handler()._sendmail = sendmail
return hs

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@ -47,12 +47,6 @@ class PasswordResetTestCase(unittest.HomeserverTestCase):
config = self.default_config()
# Email config.
self.email_attempts = []
async def sendmail(smtphost, from_addr, to_addrs, msg, **kwargs):
self.email_attempts.append(msg)
return
config["email"] = {
"enable_notifs": False,
"template_dir": os.path.abspath(
@ -67,7 +61,16 @@ class PasswordResetTestCase(unittest.HomeserverTestCase):
}
config["public_baseurl"] = "https://example.com"
hs = self.setup_test_homeserver(config=config, sendmail=sendmail)
hs = self.setup_test_homeserver(config=config)
async def sendmail(
reactor, smtphost, smtpport, from_addr, to_addrs, msg, **kwargs
):
self.email_attempts.append(msg)
self.email_attempts = []
hs.get_send_email_handler()._sendmail = sendmail
return hs
def prepare(self, reactor, clock, hs):
@ -511,11 +514,6 @@ class ThreepidEmailRestTestCase(unittest.HomeserverTestCase):
config = self.default_config()
# Email config.
self.email_attempts = []
async def sendmail(smtphost, from_addr, to_addrs, msg, **kwargs):
self.email_attempts.append(msg)
config["email"] = {
"enable_notifs": False,
"template_dir": os.path.abspath(
@ -530,7 +528,16 @@ class ThreepidEmailRestTestCase(unittest.HomeserverTestCase):
}
config["public_baseurl"] = "https://example.com"
self.hs = self.setup_test_homeserver(config=config, sendmail=sendmail)
self.hs = self.setup_test_homeserver(config=config)
async def sendmail(
reactor, smtphost, smtpport, from_addr, to_addrs, msg, **kwargs
):
self.email_attempts.append(msg)
self.email_attempts = []
self.hs.get_send_email_handler()._sendmail = sendmail
return self.hs
def prepare(self, reactor, clock, hs):

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@ -509,10 +509,6 @@ class AccountValidityRenewalByEmailTestCase(unittest.HomeserverTestCase):
}
# Email config.
self.email_attempts = []
async def sendmail(*args, **kwargs):
self.email_attempts.append((args, kwargs))
config["email"] = {
"enable_notifs": True,
@ -532,7 +528,13 @@ class AccountValidityRenewalByEmailTestCase(unittest.HomeserverTestCase):
}
config["public_baseurl"] = "aaa"
self.hs = self.setup_test_homeserver(config=config, sendmail=sendmail)
self.hs = self.setup_test_homeserver(config=config)
async def sendmail(*args, **kwargs):
self.email_attempts.append((args, kwargs))
self.email_attempts = []
self.hs.get_send_email_handler()._sendmail = sendmail
self.store = self.hs.get_datastore()