[refactor] Use sender interface in outgoing service

1 files changed, 130 insertions, 0 deletions

diff --git a/src/leap/bitmask/mail/outgoing/sender.py b/src/leap/bitmask/mail/outgoing/sender.py
new file mode 100644
index 00000000..d8c049c8
--- /dev/null
+++ b/src/leap/bitmask/mail/outgoing/sender.py
@@ -0,0 +1,130 @@
+# -*- coding: utf-8 -*-
+# outgoing/sender.py
+# Copyright (C) 2017 LEAP
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+from OpenSSL import SSL
+from StringIO import StringIO
+from twisted.internet import reactor
+from twisted.internet import defer
+from twisted.logger import Logger
+from twisted.mail import smtp
+from twisted.protocols.amp import ssl
+from zope.interface import Interface, implements
+
+from leap.common.check import leap_assert_type, leap_assert
+from leap.bitmask import __version__
+
+
+class ISender(Interface):
+    def can_send(self, recipient):
+        """
+        Checks if ISender implementor can send messages to recipient
+
+        :type recipient: string
+        :rtype: bool
+        """
+
+    def send(self, recipient, message):
+        """
+        Send a messages to recipient
+
+        :type recipient: string
+        :type message: string
+
+        :return: A Deferred that will be called with the recipient address
+        :raises SendError: in case of failure in send
+        """
+
+
+class SendError(Exception):
+    pass
+
+
+class SMTPSender(object):
+    implements(ISender)
+
+    log = Logger()
+
+    def __init__(self, from_address, key, host, port):
+        """
+        :param from_address: The sender address.
+        :type from_address: str
+        :param key: The client private key for SSL authentication.
+        :type key: str
+        :param host: The hostname of the remote SMTP server.
+        :type host: str
+        :param port: The port of the remote SMTP server.
+        :type port: int
+        """
+        leap_assert_type(host, (str, unicode))
+        leap_assert(host != '')
+        leap_assert_type(port, int)
+        leap_assert(port is not 0)
+        leap_assert_type(key, basestring)
+        leap_assert(key != '')
+
+        self._port = port
+        self._host = host
+        self._key = key
+        self._from_address = from_address
+
+    def can_send(self, recipient):
+        return '@' in recipient
+
+    def send(self, recipient, message):
+        self.log.info(
+            'Connecting to SMTP server %s:%s' % (self._host, self._port))
+
+        # we construct a defer to pass to the ESMTPSenderFactory
+        d = defer.Deferred()
+        # we don't pass an ssl context factory to the ESMTPSenderFactory
+        # because ssl will be handled by reactor.connectSSL() below.
+        factory = smtp.ESMTPSenderFactory(
+            "",  # username is blank, no client auth here
+            "",  # password is blank, no client auth here
+            self._from_address,
+            recipient.dest.addrstr,
+            StringIO(message),
+            d,
+            heloFallback=True,
+            requireAuthentication=False,
+            requireTransportSecurity=True)
+        factory.domain = bytes('leap.bitmask.mail-' + __version__)
+        reactor.connectSSL(
+            self._host, self._port, factory,
+            contextFactory=SSLContextFactory(self._key, self._key))
+        d.addCallback(lambda result: result[1][0][0])
+        d.addErrback(self._send_errback)
+        return d
+
+    def _send_errback(self, failure):
+        raise SendError(failure.getErrorMessage())
+
+
+class SSLContextFactory(ssl.ClientContextFactory):
+    def __init__(self, cert, key):
+        self.cert = cert
+        self.key = key
+
+    def getContext(self):
+        # FIXME -- we should use sslv23 to allow for tlsv1.2
+        # and, if possible, explicitely disable sslv3 clientside.
+        # Servers should avoid sslv3
+        self.method = SSL.TLSv1_METHOD  # SSLv23_METHOD
+        ctx = ssl.ClientContextFactory.getContext(self)
+        ctx.use_certificate_file(self.cert)
+        ctx.use_privatekey_file(self.key)
+        return ctx