1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
#!/usr/bin/env python
# -*- encoding: utf-8 -*-
# mail_receiver.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/>.
"""
MailReceiver service definition
"""
import os
import uuid as pyuuid
import json
from email import message_from_string
from twisted.application.service import Service
from twisted.internet import inotify
from twisted.internet.defer import DeferredList
from twisted.python import filepath, log
from leap.soledad.document import SoledadDocument
from leap.soledad.target import EncryptionSchemes
from leap.soledad_server.couch import CouchDatabase
from leap.keymanager import openpgp
class MailReceiver(Service):
"""
Service that monitors incoming email and processes it
"""
def __init__(self, mail_couch_url, users_cdb, directories):
"""
Constructor
@param mail_couch_url: URL prefix for the couchdb where mail
should be stored
@type mail_couch_url: str
@param users_cdb: CouchDB instance from where to get the uuid
and pubkey for a user
@type users_cdb: ConnectedCouchDB
@param directories: list of directories to monitor
@type directories: list of tuples (path: str, recursive: bool)
"""
# Service doesn't define an __init__
self._mail_couch_url = mail_couch_url
self._users_cdb = users_cdb
self._directories = directories
def startService(self):
"""
Starts the MailReceiver service
"""
Service.startService(self)
wm = inotify.INotify()
wm.startReading()
mask = inotify.IN_CREATE
for directory, recursive in self._directories:
log.msg("Watching %s --- Recursive: %s" % (directory, recursive))
wm.watch(filepath.FilePath(directory), mask,
callbacks=[self._process_incoming_email],
recursive=recursive)
def _gather_uuid_pubkey(self, results):
if len(results) < 2:
return None, None
# DeferredList results are structured like this:
# [ (succeeded, pubkey), (succeeded, uuid) ]
# succeeded is a bool value that specifies if the
# corresponding callback succeeded
pubkey_res, uuid_res = results
pubkey = pubkey_res[1] if pubkey_res[0] else None
uuid = uuid_res[1] if uuid_res[0] else None
return uuid, pubkey
def _encrypt_message(self, uuid_pubkey, address, message):
"""
Given a UUID, a public key, address and a message, it encrypts
the message to that public key.
The address is needed in order to build the OpenPGPKey object.
@param uuid_pubkey: tuple that holds the uuid and the public
key as it is returned by the previous call in the chain
@type uuid_pubkey: tuple (str, str)
@param address: mail address for this message
@type address: str
@param message: message contents
@type message: str
@return: uuid, doc to sync with Soledad
@rtype: tuple(str, SoledadDocument)
"""
uuid, pubkey = uuid_pubkey
log.msg("Encrypting message to %s's pubkey" % (uuid,))
log.msg("Pubkey: %s" % (pubkey,))
doc = SoledadDocument(doc_id=str(pyuuid.uuid4()))
data = {'incoming': True, 'content': message}
if pubkey is None or len(pubkey) == 0:
doc.content = {
"incoming": True,
"_enc_scheme": EncryptionSchemes.NONE,
"_enc_json": json.dumps(data)
}
return uuid, doc
openpgp_key = None
with openpgp.TempGPGWrapper(gpgbinary='/usr/bin/gpg') as gpg:
gpg.import_keys(pubkey)
key = gpg.list_keys().pop()
openpgp_key = openpgp._build_key_from_gpg(address, key, pubkey)
doc.content = {
"incoming": True,
"_enc_scheme": EncryptionSchemes.PUBKEY,
"_enc_json": str(gpg.encrypt(
json.dumps(data),
openpgp_key.fingerprint,
symmetric=False))
}
return uuid, doc
def _export_message(self, uuid_doc):
"""
Given a UUID and a SoledadDocument, it saves it directly in the
couchdb that serves as a backend for Soledad, in a db
accessible to the recipient of the mail
@param uuid_doc: tuple that holds the UUID and SoledadDocument
@type uuid_doc: tuple(str, SoledadDocument)
@return: True if it's ok to remove the message, False
otherwise
@rtype: bool
"""
uuid, doc = uuid_doc
log.msg("Exporting message for %s" % (uuid,))
if uuid is None:
uuid = 0
db = CouchDatabase(self._mail_couch_url, "user-%s" % (uuid,))
log.msg("Done exporting")
return True
def _conditional_remove(self, do_remove, filepath):
"""
Removes the message if do_remove is True
@param do_remove: True if the message should be removed, False
otherwise
@type do_remove: bool
@param filepath: path to the mail
@type filepath: twisted.python.filepath.FilePath
"""
if do_remove:
# remove the original mail
try:
log.msg("Removing %s" % (filepath.path,))
filepath.remove()
log.msg("Done removing")
except:
log.err()
def _process_incoming_email(self, otherself, filepath, mask):
"""
Callback that processes incoming email
@param otherself: Watch object for the current callback from
inotify
@type otherself: twisted.internet.inotify._Watch
@param filepath: Path of the file that changed
@type filepath: twisted.python.filepath.FilePath
@param mask: identifier for the type of change that triggered
this callback
@type mask: int
"""
if os.path.split(filepath.dirname())[-1] == "new":
log.msg("Processing new mail at %s" % (filepath.path,))
with filepath.open("r") as f:
mail_data = f.read()
mail = message_from_string(mail_data)
owner = mail["To"]
if owner is None: # default to Delivered-To
owner = mail["Delivered-To"]
if owner is None:
log.err("Malformed mail, neither To: nor "
"Delivered-To: field")
log.msg("Mail owner: %s" % (owner,))
log.msg("%s received a new mail" % (owner,))
dpubk = self._users_cdb.getPubKey(owner)
duuid = self._users_cdb.queryByAddress(owner)
d = DeferredList([dpubk, duuid])
d.addCallbacks(self._gather_uuid_pubkey, log.err)
d.addCallbacks(self._encrypt_message, log.err,
(owner, mail_data))
d.addCallbacks(self._export_message, log.err)
d.addCallbacks(self._conditional_remove, log.err,
(filepath,))
d.addErrback(log.err)
|
