diff options
| -rw-r--r-- | changelog.d/13317.feature | 1 | ||||
| -rw-r--r-- | docs/usage/configuration/config_documentation.md | 11 | ||||
| -rw-r--r-- | synapse/config/emailconfig.py | 7 | ||||
| -rw-r--r-- | synapse/handlers/send_email.py | 36 | ||||
| -rw-r--r-- | tests/handlers/test_send_email.py | 57 |
5 files changed, 99 insertions, 13 deletions
diff --git a/changelog.d/13317.feature b/changelog.d/13317.feature new file mode 100644 index 0000000000..e0ebd2b51f --- /dev/null +++ b/changelog.d/13317.feature @@ -0,0 +1 @@ +Support Implicit TLS for sending emails, enabled by the new option `force_tls`. Contributed by Jan Schär. diff --git a/docs/usage/configuration/config_documentation.md b/docs/usage/configuration/config_documentation.md index a10f6662eb..eefcc7829d 100644 --- a/docs/usage/configuration/config_documentation.md +++ b/docs/usage/configuration/config_documentation.md @@ -3187,9 +3187,17 @@ Server admins can configure custom templates for email content. See This setting has the following sub-options: * `smtp_host`: The hostname of the outgoing SMTP server to use. Defaults to 'localhost'. -* `smtp_port`: The port on the mail server for outgoing SMTP. Defaults to 25. +* `smtp_port`: The port on the mail server for outgoing SMTP. Defaults to 465 if `force_tls` is true, else 25. + + _Changed in Synapse 1.64.0:_ the default port is now aware of `force_tls`. * `smtp_user` and `smtp_pass`: Username/password for authentication to the SMTP server. By default, no authentication is attempted. +* `force_tls`: By default, Synapse connects over plain text and then optionally upgrades + to TLS via STARTTLS. If this option is set to true, TLS is used from the start (Implicit TLS), + and the option `require_transport_security` is ignored. + It is recommended to enable this if supported by your mail server. + + _New in Synapse 1.64.0._ * `require_transport_security`: Set to true to require TLS transport security for SMTP. By default, Synapse will connect over plain text, and will then switch to TLS via STARTTLS *if the SMTP server supports it*. If this option is set, @@ -3254,6 +3262,7 @@ email: smtp_port: 587 smtp_user: "exampleusername" smtp_pass: "examplepassword" + force_tls: true require_transport_security: true enable_tls: false notif_from: "Your Friendly %(app)s homeserver <noreply@example.com>" diff --git a/synapse/config/emailconfig.py b/synapse/config/emailconfig.py index 3ead80d985..73b469f414 100644 --- a/synapse/config/emailconfig.py +++ b/synapse/config/emailconfig.py @@ -85,14 +85,19 @@ class EmailConfig(Config): if email_config is None: email_config = {} + self.force_tls = email_config.get("force_tls", False) self.email_smtp_host = email_config.get("smtp_host", "localhost") - self.email_smtp_port = email_config.get("smtp_port", 25) + self.email_smtp_port = email_config.get( + "smtp_port", 465 if self.force_tls else 25 + ) self.email_smtp_user = email_config.get("smtp_user", None) self.email_smtp_pass = email_config.get("smtp_pass", None) self.require_transport_security = email_config.get( "require_transport_security", False ) self.enable_smtp_tls = email_config.get("enable_tls", True) + if self.force_tls and not self.enable_smtp_tls: + raise ConfigError("email.force_tls requires email.enable_tls to be 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" diff --git a/synapse/handlers/send_email.py b/synapse/handlers/send_email.py index a305a66860..e2844799e8 100644 --- a/synapse/handlers/send_email.py +++ b/synapse/handlers/send_email.py @@ -23,10 +23,12 @@ from pkg_resources import parse_version import twisted from twisted.internet.defer import Deferred -from twisted.internet.interfaces import IOpenSSLContextFactory, IReactorTCP +from twisted.internet.interfaces import IOpenSSLContextFactory +from twisted.internet.ssl import optionsForClientTLS from twisted.mail.smtp import ESMTPSender, ESMTPSenderFactory from synapse.logging.context import make_deferred_yieldable +from synapse.types import ISynapseReactor if TYPE_CHECKING: from synapse.server import HomeServer @@ -48,7 +50,7 @@ class _NoTLSESMTPSender(ESMTPSender): async def _sendmail( - reactor: IReactorTCP, + reactor: ISynapseReactor, smtphost: str, smtpport: int, from_addr: str, @@ -59,6 +61,7 @@ async def _sendmail( require_auth: bool = False, require_tls: bool = False, enable_tls: bool = True, + force_tls: bool = False, ) -> None: """A simple wrapper around ESMTPSenderFactory, to allow substitution in tests @@ -73,8 +76,9 @@ async def _sendmail( 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 - enable_tls: True to enable TLS. If this is False and require_tls is True, + enable_tls: True to enable STARTTLS. If this is False and require_tls is True, the request will fail. + force_tls: True to enable Implicit TLS. """ msg = BytesIO(msg_bytes) d: "Deferred[object]" = Deferred() @@ -105,13 +109,23 @@ async def _sendmail( # set to enable TLS. factory = build_sender_factory(hostname=smtphost if enable_tls else None) - reactor.connectTCP( - smtphost, - smtpport, - factory, - timeout=30, - bindAddress=None, - ) + if force_tls: + reactor.connectSSL( + smtphost, + smtpport, + factory, + optionsForClientTLS(smtphost), + timeout=30, + bindAddress=None, + ) + else: + reactor.connectTCP( + smtphost, + smtpport, + factory, + timeout=30, + bindAddress=None, + ) await make_deferred_yieldable(d) @@ -132,6 +146,7 @@ class SendEmailHandler: 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._force_tls = hs.config.email.force_tls self._sendmail = _sendmail @@ -189,4 +204,5 @@ class SendEmailHandler: require_auth=self._smtp_user is not None, require_tls=self._require_transport_security, enable_tls=self._enable_tls, + force_tls=self._force_tls, ) diff --git a/tests/handlers/test_send_email.py b/tests/handlers/test_send_email.py index 6f77b1237c..da4bf8b582 100644 --- a/tests/handlers/test_send_email.py +++ b/tests/handlers/test_send_email.py @@ -23,7 +23,7 @@ from twisted.internet.defer import ensureDeferred from twisted.mail import interfaces, smtp from tests.server import FakeTransport -from tests.unittest import HomeserverTestCase +from tests.unittest import HomeserverTestCase, override_config @implementer(interfaces.IMessageDelivery) @@ -110,3 +110,58 @@ class SendEmailHandlerTestCase(HomeserverTestCase): user, msg = message_delivery.messages.pop() self.assertEqual(str(user), "foo@bar.com") self.assertIn(b"Subject: test subject", msg) + + @override_config( + { + "email": { + "notif_from": "noreply@test", + "force_tls": True, + }, + } + ) + def test_send_email_force_tls(self): + """Happy-path test that we can send email to an Implicit TLS server.""" + h = self.hs.get_send_email_handler() + d = ensureDeferred( + h.send_email( + "foo@bar.com", "test subject", "Tests", "HTML content", "Text content" + ) + ) + # there should be an attempt to connect to localhost:465 + self.assertEqual(len(self.reactor.sslClients), 1) + ( + host, + port, + client_factory, + contextFactory, + _timeout, + _bindAddress, + ) = self.reactor.sslClients[0] + self.assertEqual(host, "localhost") + self.assertEqual(port, 465) + + # wire it up to an SMTP server + message_delivery = _DummyMessageDelivery() + server_protocol = smtp.ESMTP() + server_protocol.delivery = message_delivery + # make sure that the server uses the test reactor to set timeouts + server_protocol.callLater = self.reactor.callLater # type: ignore[assignment] + + client_protocol = client_factory.buildProtocol(None) + client_protocol.makeConnection(FakeTransport(server_protocol, self.reactor)) + server_protocol.makeConnection( + FakeTransport( + client_protocol, + self.reactor, + peer_address=IPv4Address("TCP", "127.0.0.1", 1234), + ) + ) + + # the message should now get delivered + self.get_success(d, by=0.1) + + # check it arrived + self.assertEqual(len(message_delivery.messages), 1) + user, msg = message_delivery.messages.pop() + self.assertEqual(str(user), "foo@bar.com") + self.assertIn(b"Subject: test subject", msg) |