# # This file is licensed under the Affero General Public License (AGPL) version 3. # # Copyright (C) 2023 New Vector, Ltd # # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU Affero General Public License as # published by the Free Software Foundation, either version 3 of the # License, or (at your option) any later version. # # See the GNU Affero General Public License for more details: # . # # Originally licensed under the Apache License, Version 2.0: # . # # [This file includes modifications made by New Vector Limited] # # from typing import Callable, List, Tuple, Type, Union from unittest.mock import patch from zope.interface import implementer from twisted.internet import defer from twisted.internet._sslverify import ClientTLSOptions from twisted.internet.address import IPv4Address, IPv6Address from twisted.internet.defer import ensureDeferred from twisted.internet.interfaces import IProtocolFactory from twisted.internet.ssl import ContextFactory from twisted.mail import interfaces, smtp from tests.server import FakeTransport from tests.unittest import HomeserverTestCase, override_config def TestingESMTPTLSClientFactory( contextFactory: ContextFactory, _connectWrapped: bool, wrappedProtocol: IProtocolFactory, ) -> IProtocolFactory: """We use this to pass through in testing without using TLS, but saving the context information to check that it would have happened. Note that this is what the MemoryReactor does on connectSSL. It only saves the contextFactory, but starts the connection with the underlying Factory. See: L{twisted.internet.testing.MemoryReactor.connectSSL}""" wrappedProtocol._testingContextFactory = contextFactory # type: ignore[attr-defined] return wrappedProtocol @implementer(interfaces.IMessageDelivery) class _DummyMessageDelivery: def __init__(self) -> None: # (recipient, message) tuples self.messages: List[Tuple[smtp.Address, bytes]] = [] def receivedHeader( self, helo: Tuple[bytes, bytes], origin: smtp.Address, recipients: List[smtp.User], ) -> None: return None def validateFrom( self, helo: Tuple[bytes, bytes], origin: smtp.Address ) -> smtp.Address: return origin def record_message(self, recipient: smtp.Address, message: bytes) -> None: self.messages.append((recipient, message)) def validateTo(self, user: smtp.User) -> Callable[[], interfaces.IMessageSMTP]: return lambda: _DummyMessage(self, user) @implementer(interfaces.IMessageSMTP) class _DummyMessage: """IMessageSMTP implementation which saves the message delivered to it to the _DummyMessageDelivery object. """ def __init__(self, delivery: _DummyMessageDelivery, user: smtp.User): self._delivery = delivery self._user = user self._buffer: List[bytes] = [] def lineReceived(self, line: bytes) -> None: self._buffer.append(line) def eomReceived(self) -> "defer.Deferred[bytes]": message = b"\n".join(self._buffer) + b"\n" self._delivery.record_message(self._user.dest, message) return defer.succeed(b"saved") def connectionLost(self) -> None: pass class SendEmailHandlerTestCaseIPv4(HomeserverTestCase): ip_class: Union[Type[IPv4Address], Type[IPv6Address]] = IPv4Address def setUp(self) -> None: super().setUp() self.reactor.lookups["localhost"] = "127.0.0.1" def test_send_email(self) -> None: """Happy-path test that we can send email to a non-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:25 self.assertEqual(len(self.reactor.tcpClients), 1) (host, port, client_factory, _timeout, _bindAddress) = self.reactor.tcpClients[ 0 ] self.assertEqual(host, self.reactor.lookups["localhost"]) self.assertEqual(port, 25) # 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=self.ip_class( "TCP", self.reactor.lookups["localhost"], 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) @patch( "synapse.handlers.send_email.TLSMemoryBIOFactory", TestingESMTPTLSClientFactory, ) @override_config( { "email": { "notif_from": "noreply@test", "force_tls": True, }, } ) def test_send_email_force_tls(self) -> None: """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.tcpClients), 1) ( host, port, client_factory, _timeout, _bindAddress, ) = self.reactor.tcpClients[0] self.assertEqual(host, self.reactor.lookups["localhost"]) self.assertEqual(port, 465) # We need to make sure that TLS is happenning self.assertIsInstance( client_factory._wrappedFactory._testingContextFactory, ClientTLSOptions, ) # And since we use endpoints, they go through reactor.connectTCP # which works differently to connectSSL on the testing reactor # 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=self.ip_class( "TCP", self.reactor.lookups["localhost"], 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) class SendEmailHandlerTestCaseIPv6(SendEmailHandlerTestCaseIPv4): ip_class = IPv6Address def setUp(self) -> None: super().setUp() self.reactor.lookups["localhost"] = "::1"