From f05b0ec45ac667e85a610219d77906f049eb58cc Mon Sep 17 00:00:00 2001 From: Kali Kaneko Date: Tue, 29 Mar 2016 17:21:43 -0400 Subject: [feature] SMTP delivery bounces We catch any error on SMTP delivery and format it as a bounce message delivered to the user Inbox. this doesn't comply with the bounce format, but it's a nice first start. leaving proper structuring of the delivery failure report for future iterations. - Resolves: #7263 --- changes/next-changelog.rst | 1 + src/leap/mail/outgoing/service.py | 44 +++++++++++++------ src/leap/mail/smtp/bounces.py | 89 +++++++++++++++++++++++++++++++++++++++ src/leap/mail/smtp/gateway.py | 47 +++++++++++++++++---- 4 files changed, 160 insertions(+), 21 deletions(-) create mode 100644 src/leap/mail/smtp/bounces.py diff --git a/changes/next-changelog.rst b/changes/next-changelog.rst index f89af89..9b2a9d6 100644 --- a/changes/next-changelog.rst +++ b/changes/next-changelog.rst @@ -13,6 +13,7 @@ Features - `#7656 `_: Emit multi-user aware events. - `#4008 `_: Add token-based authentication to local IMAP/SMTP services. - `#7889 `_: Use cryptography instead of pycryptopp to reduce dependencies. +- `#7263 `_: Implement local bounces to notify user of SMTP delivery errors. - Use twisted.cred to authenticate IMAP users. - `#1234 `_: Description of the new feature corresponding with issue #1234. diff --git a/src/leap/mail/outgoing/service.py b/src/leap/mail/outgoing/service.py index eeb5d32..335cae4 100644 --- a/src/leap/mail/outgoing/service.py +++ b/src/leap/mail/outgoing/service.py @@ -73,7 +73,7 @@ class SSLContextFactory(ssl.ClientContextFactory): return ctx -def outgoingFactory(userid, keymanager, opts, check_cert=True): +def outgoingFactory(userid, keymanager, opts, check_cert=True, bouncer=None): cert = unicode(opts.cert) key = unicode(opts.key) @@ -85,7 +85,9 @@ def outgoingFactory(userid, keymanager, opts, check_cert=True): raise errors.ConfigurationError( 'No valid SMTP certificate could be found for %s!' % userid) - return OutgoingMail(str(userid), keymanager, cert, key, hostname, port) + return OutgoingMail( + str(userid), keymanager, cert, key, hostname, port, + bouncer) class OutgoingMail(object): @@ -93,7 +95,8 @@ class OutgoingMail(object): Sends Outgoing Mail, encrypting and signing if needed. """ - def __init__(self, from_address, keymanager, cert, key, host, port): + def __init__(self, from_address, keymanager, cert, key, host, port, + bouncer=None): """ Initialize the outgoing mail service. @@ -133,6 +136,7 @@ class OutgoingMail(object): self._cert = cert self._from_address = from_address self._keymanager = keymanager + self._bouncer = bouncer def send_message(self, raw, recipient): """ @@ -145,8 +149,8 @@ class OutgoingMail(object): :return: a deferred which delivers the message when fired """ d = self._maybe_encrypt_and_sign(raw, recipient) - d.addCallback(self._route_msg) - d.addErrback(self.sendError) + d.addCallback(self._route_msg, raw) + d.addErrback(self.sendError, raw) return d def sendSuccess(self, smtp_sender_result): @@ -163,21 +167,36 @@ class OutgoingMail(object): emit_async(catalog.SMTP_SEND_MESSAGE_SUCCESS, fromaddr, dest_addrstr) - def sendError(self, failure): + def sendError(self, failure, origmsg): """ Callback for an unsuccessfull send. - :param e: The result from the last errback. - :type e: anything + :param failure: The result from the last errback. + :type failure: anything + :param origmsg: the original, unencrypted, raw message, to be passed to + the bouncer. + :type origmsg: str """ - # XXX: need to get the address from the exception to send signal + # XXX: need to get the address from the original message to send signal # emit_async(catalog.SMTP_SEND_MESSAGE_ERROR, self._from_address, # self._user.dest.addrstr) + + # TODO when we implement outgoing queues/long-term-retries, we could + # examine the error *here* and delay the notification if it's just a + # temporal error. We might want to notify the permanent errors + # differently. + err = failure.value log.err(err) - raise err - def _route_msg(self, encrypt_and_sign_result): + if self._bouncer: + self._bouncer.bounce_message( + err.message, to=self._from_address, + orig=origmsg) + else: + raise err + + def _route_msg(self, encrypt_and_sign_result, raw): """ Sends the msg using the ESMTPSenderFactory. @@ -191,7 +210,8 @@ class OutgoingMail(object): # we construct a defer to pass to the ESMTPSenderFactory d = defer.Deferred() - d.addCallbacks(self.sendSuccess, self.sendError) + d.addCallback(self.sendSuccess) + d.addErrback(self.sendError, raw) # we don't pass an ssl context factory to the ESMTPSenderFactory # because ssl will be handled by reactor.connectSSL() below. factory = smtp.ESMTPSenderFactory( diff --git a/src/leap/mail/smtp/bounces.py b/src/leap/mail/smtp/bounces.py new file mode 100644 index 0000000..64f2dd7 --- /dev/null +++ b/src/leap/mail/smtp/bounces.py @@ -0,0 +1,89 @@ +# -*- coding: utf-8 -*- +# bounces.py +# Copyright (C) 2016 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 . +""" +Deliver bounces to the user Inbox. +""" +import time +from email.message import Message +from email.utils import formatdate + +from leap.mail.constants import INBOX_NAME +from leap.mail.mail import Account + + +# TODO implement localization for this template. + +BOUNCE_TEMPLATE = """This is your local Bitmask Mail Agent running at localhost. + +I'm sorry to have to inform you that your message could not be delivered to one +or more recipients. + +The reasons I got for the error are: + +{raw_error} + +If the problem persists and it's not a network connectivity issue, you might +want to contact your provider ({provider}) with this information (remove any +sensitive data before). + +--- Original message (*before* it was encrypted by bitmask) below ----: + +{orig}""" + + +class Bouncer(object): + """ + Implements a mechanism to deliver bounces to user inbox. + """ + # TODO this should follow RFC 6522, and compose a correct multipart + # attaching the report and the original message. Leaving this for a future + # iteration. + + def __init__(self, inbox_collection): + self._inbox_collection = inbox_collection + + def bounce_message(self, error_data, to, date=None, orig=''): + if not date: + date = formatdate(time.time()) + + raw_data = self._format_msg(error_data, to, date, orig) + d = self._inbox_collection.add_msg( + raw_data, ('\\Recent',), date=date) + return d + + def _format_msg(self, error_data, to, date, orig): + provider = to.split('@')[1] + + msg = Message() + msg.add_header( + 'From', 'bitmask-bouncer@localhost (Bitmask Local Agent)') + msg.add_header('To', to) + msg.add_header('Subject', 'Undelivered Message') + msg.add_header('Date', date) + msg.set_payload(BOUNCE_TEMPLATE.format( + raw_error=error_data, + provider=provider, + orig=orig)) + + return msg.as_string() + + +def bouncerFactory(soledad): + acc = Account(soledad) + d = acc.callWhenReady(lambda _: acc.get_collection_by_mailbox(INBOX_NAME)) + d.addCallback(lambda inbox: Bouncer(inbox)) + return d diff --git a/src/leap/mail/smtp/gateway.py b/src/leap/mail/smtp/gateway.py index 7ff6b14..cb1b060 100644 --- a/src/leap/mail/smtp/gateway.py +++ b/src/leap/mail/smtp/gateway.py @@ -29,7 +29,6 @@ The following classes comprise the SMTP gateway service: * EncryptedMessage - An implementation of twisted.mail.smtp.IMessage that knows how to encrypt/sign itself before sending. """ - from email.Header import Header from zope.interface import implements @@ -48,6 +47,7 @@ from leap.mail.cred import LocalSoledadTokenChecker from leap.mail.utils import validate_address from leap.mail.rfc3156 import RFC3156CompliantGenerator from leap.mail.outgoing.service import outgoingFactory +from leap.mail.smtp.bounces import bouncerFactory from leap.keymanager.openpgp import OpenPGPKey from leap.keymanager.errors import KeyNotFound @@ -65,7 +65,7 @@ class LocalSMTPRealm(object): _encoding = 'utf-8' - def __init__(self, keymanager_sessions, sendmail_opts, + def __init__(self, keymanager_sessions, soledad_sessions, sendmail_opts, encrypted_only=False): """ :param keymanager_sessions: a dict-like object, containing instances @@ -73,21 +73,31 @@ class LocalSMTPRealm(object): userid. """ self._keymanager_sessions = keymanager_sessions + self._soledad_sessions = soledad_sessions self._sendmail_opts = sendmail_opts self.encrypted_only = encrypted_only def requestAvatar(self, avatarId, mind, *interfaces): + if isinstance(avatarId, str): avatarId = avatarId.decode(self._encoding) - def gotKeymanager(keymanager): + def gotKeymanagerAndSoledad(result): + keymanager, soledad = result + d = bouncerFactory(soledad) + d.addCallback(lambda bouncer: (keymanager, soledad, bouncer)) + return d + def getMessageDelivery(result): + keymanager, soledad, bouncer = result # TODO use IMessageDeliveryFactory instead ? # it could reuse the connections. if smtp.IMessageDelivery in interfaces: userid = avatarId opts = self.getSendingOpts(userid) - outgoing = outgoingFactory(userid, keymanager, opts) + + outgoing = outgoingFactory( + userid, keymanager, opts, bouncer=bouncer) avatar = SMTPDelivery(userid, keymanager, self.encrypted_only, outgoing) @@ -96,10 +106,15 @@ class LocalSMTPRealm(object): raise NotImplementedError(self, interfaces) - return self.lookupKeymanagerInstance(avatarId).addCallback( - gotKeymanager) + d1 = self.lookupKeymanagerInstance(avatarId) + d2 = self.lookupSoledadInstance(avatarId) + d = defer.gatherResults([d1, d2]) + d.addCallback(gotKeymanagerAndSoledad) + d.addCallback(getMessageDelivery) + return d def lookupKeymanagerInstance(self, userid): + print 'getting KM INSTNACE>>>' try: keymanager = self._keymanager_sessions[userid] except: @@ -109,6 +124,16 @@ class LocalSMTPRealm(object): # XXX this should return the instance after whenReady callback return defer.succeed(keymanager) + def lookupSoledadInstance(self, userid): + try: + soledad = self._soledad_sessions[userid] + except: + raise errors.AuthenticationError( + 'No soledad session found for user %s. Is it authenticated?' + % userid) + # XXX this should return the instance after whenReady callback + return defer.succeed(soledad) + def getSendingOpts(self, userid): try: opts = self._sendmail_opts[userid] @@ -134,8 +159,9 @@ class LEAPInitMixin(object): """ def __init__(self, soledad_sessions, keymanager_sessions, sendmail_opts, encrypted_only=False): - realm = LocalSMTPRealm(keymanager_sessions, sendmail_opts, - encrypted_only) + realm = LocalSMTPRealm( + keymanager_sessions, soledad_sessions, sendmail_opts, + encrypted_only) portal = Portal(realm) checker = SMTPTokenChecker(soledad_sessions) @@ -161,6 +187,7 @@ class LocalSMTPServer(smtp.ESMTP, LEAPInitMixin): smtp.ESMTP.__init__(self, *args, **kw) +# TODO implement retries -- see smtp.SenderMixin class SMTPFactory(protocol.ServerFactory): """ Factory for an SMTP server with encrypted gatewaying capabilities. @@ -171,7 +198,9 @@ class SMTPFactory(protocol.ServerFactory): timeout = 600 encrypted_only = False - def __init__(self, soledad_sessions, keymanager_sessions, sendmail_opts): + def __init__(self, soledad_sessions, keymanager_sessions, sendmail_opts, + deferred=None, retries=3): + self._soledad_sessions = soledad_sessions self._keymanager_sessions = keymanager_sessions self._sendmail_opts = sendmail_opts -- cgit v1.2.3