Moving encrypt, sign and send logic from gateway (SMTP) to a MailService

1 files changed, 185 insertions, 0 deletions

diff --git a/src/leap/mail/tests/test_service.py b/src/leap/mail/tests/test_service.py
new file mode 100644
index 0000000..f0a807d
--- /dev/null
+++ b/src/leap/mail/tests/test_service.py
@@ -0,0 +1,185 @@
+# -*- coding: utf-8 -*-
+# test_gateway.py
+# Copyright (C) 2013 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/>.
+
+
+"""
+SMTP gateway tests.
+"""
+
+import re
+from datetime import datetime
+from twisted.mail.smtp import User, Address
+
+from mock import Mock
+
+from leap.mail.smtp.gateway import SMTPFactory
+from leap.mail.service import OutgoingMail
+from leap.mail.tests import (
+    TestCaseWithKeyManager,
+    ADDRESS,
+    ADDRESS_2,
+)
+from leap.keymanager import openpgp
+
+
+class TestOutgoingMail(TestCaseWithKeyManager):
+    EMAIL_DATA = ['HELO gateway.leap.se',
+                  'MAIL FROM: <%s>' % ADDRESS_2,
+                  'RCPT TO: <%s>' % ADDRESS,
+                  'DATA',
+                  'From: User <%s>' % ADDRESS_2,
+                  'To: Leap <%s>' % ADDRESS,
+                  'Date: ' + datetime.now().strftime('%c'),
+                  'Subject: test message',
+                  '',
+                  'This is a secret message.',
+                  'Yours,',
+                  'A.',
+                  '',
+                  '.',
+                  'QUIT']
+
+    def setUp(self):
+        TestCaseWithKeyManager.setUp(self)
+        self.lines = [line for line in self.EMAIL_DATA[4:12]]
+        self.lines.append('')  # add a trailing newline
+        self.raw = '\r\n'.join(self.lines)
+        self.fromAddr = ADDRESS_2
+        self.outgoing_mail = OutgoingMail(self.fromAddr, self._km, self._config['cert'], self._config['key'],
+                                        self._config['host'], self._config['port'])
+        self.proto = SMTPFactory(
+            u'anotheruser@leap.se',
+            self._km,
+            self._config['encrypted_only'],
+            self.outgoing_mail).buildProtocol(('127.0.0.1', 0))
+        self.dest = User(ADDRESS, 'gateway.leap.se', self.proto, ADDRESS)
+
+    def test_openpgp_encrypt_decrypt(self):
+        "Test if openpgp can encrypt and decrypt."
+        text = "simple raw text"
+        pubkey = self._km.get_key(
+            ADDRESS, openpgp.OpenPGPKey, private=False)
+        encrypted = self._km.encrypt(text, pubkey)
+        self.assertNotEqual(
+            text, encrypted, "Ciphertext is equal to plaintext.")
+        privkey = self._km.get_key(
+            ADDRESS, openpgp.OpenPGPKey, private=True)
+        decrypted = self._km.decrypt(encrypted, privkey)
+        self.assertEqual(text, decrypted,
+                         "Decrypted text differs from plaintext.")
+
+    def test_message_encrypt(self):
+        """
+        Test if message gets encrypted to destination email.
+        """
+
+        message, _ = self.outgoing_mail._maybe_encrypt_and_sign(self.raw, self.dest)
+
+        # assert structure of encrypted message
+        self.assertTrue('Content-Type' in message)
+        self.assertEqual('multipart/encrypted', message.get_content_type())
+        self.assertEqual('application/pgp-encrypted',
+                         message.get_param('protocol'))
+        self.assertEqual(2, len(message.get_payload()))
+        self.assertEqual('application/pgp-encrypted',
+                         message.get_payload(0).get_content_type())
+        self.assertEqual('application/octet-stream',
+                         message.get_payload(1).get_content_type())
+        privkey = self._km.get_key(
+            ADDRESS, openpgp.OpenPGPKey, private=True)
+        decrypted = self._km.decrypt(
+            message.get_payload(1).get_payload(), privkey)
+
+        expected = '\n' + '\r\n'.join(
+            self.EMAIL_DATA[9:12]) + '\r\n\r\n--\r\n' + 'I prefer encrypted email - https://leap.se/key/anotheruser\r\n'
+        self.assertEqual(
+            expected,
+            decrypted,
+            'Decrypted text differs from plaintext.')
+
+    def test_message_encrypt_sign(self):
+        """
+        Test if message gets encrypted to destination email and signed with
+        sender key.
+        """
+        message, _ = self.outgoing_mail._maybe_encrypt_and_sign(self.raw, self.dest)
+
+        # assert structure of encrypted message
+        self.assertTrue('Content-Type' in message)
+        self.assertEqual('multipart/encrypted', message.get_content_type())
+        self.assertEqual('application/pgp-encrypted',
+                         message.get_param('protocol'))
+        self.assertEqual(2, len(message.get_payload()))
+        self.assertEqual('application/pgp-encrypted',
+                         message.get_payload(0).get_content_type())
+        self.assertEqual('application/octet-stream',
+                         message.get_payload(1).get_content_type())
+        # decrypt and verify
+        privkey = self._km.get_key(
+            ADDRESS, openpgp.OpenPGPKey, private=True)
+        pubkey = self._km.get_key(ADDRESS_2, openpgp.OpenPGPKey)
+        decrypted = self._km.decrypt(
+            message.get_payload(1).get_payload(), privkey, verify=pubkey)
+        self.assertEqual(
+            '\n' + '\r\n'.join(self.EMAIL_DATA[9:12]) + '\r\n\r\n--\r\n' +
+            'I prefer encrypted email - https://leap.se/key/anotheruser\r\n',
+            decrypted,
+            'Decrypted text differs from plaintext.')
+
+    def test_message_sign(self):
+        """
+        Test if message is signed with sender key.
+        """
+        # mock the key fetching
+        self._km.fetch_keys_from_server = Mock(return_value=[])
+        recipient = User('ihavenopubkey@nonleap.se',
+                    'gateway.leap.se', self.proto, ADDRESS)
+        self.outgoing_mail = OutgoingMail(self.fromAddr, self._km, self._config['cert'], self._config['key'],
+                                        self._config['host'], self._config['port'])
+
+        message, _ = self.outgoing_mail._maybe_encrypt_and_sign(self.raw, recipient)
+
+        # assert structure of signed message
+        self.assertTrue('Content-Type' in message)
+        self.assertEqual('multipart/signed', message.get_content_type())
+        self.assertEqual('application/pgp-signature',
+                         message.get_param('protocol'))
+        self.assertEqual('pgp-sha512', message.get_param('micalg'))
+        # assert content of message
+        self.assertEqual(
+            '\r\n'.join(self.EMAIL_DATA[9:13]) + '\r\n--\r\n' +
+            'I prefer encrypted email - https://leap.se/key/anotheruser\r\n',
+            message.get_payload(0).get_payload(decode=True))
+        # assert content of signature
+        self.assertTrue(
+            message.get_payload(1).get_payload().startswith(
+                '-----BEGIN PGP SIGNATURE-----\n'),
+            'Message does not start with signature header.')
+        self.assertTrue(
+            message.get_payload(1).get_payload().endswith(
+                '-----END PGP SIGNATURE-----\n'),
+            'Message does not end with signature footer.')
+        # assert signature is valid
+        pubkey = self._km.get_key(ADDRESS_2, openpgp.OpenPGPKey)
+        # replace EOL before verifying (according to rfc3156)
+        signed_text = re.sub('\r?\n', '\r\n',
+                             message.get_payload(0).as_string())
+        self.assertTrue(
+            self._km.verify(signed_text,
+                            pubkey,
+                            detached_sig=message.get_payload(1).get_payload()),
+            'Signature could not be verified.')