diff options
Diffstat (limited to 'src/leap/mail/imap/fetch.py')
| -rw-r--r-- | src/leap/mail/imap/fetch.py | 312 |
1 files changed, 165 insertions, 147 deletions
diff --git a/src/leap/mail/imap/fetch.py b/src/leap/mail/imap/fetch.py index 01373be..dbc726a 100644 --- a/src/leap/mail/imap/fetch.py +++ b/src/leap/mail/imap/fetch.py @@ -36,7 +36,6 @@ from twisted.internet import defer, reactor from twisted.internet.task import LoopingCall from twisted.internet.task import deferLater from u1db import errors as u1db_errors -from zope.proxy import sameProxiedObjects from leap.common import events as leap_events from leap.common.check import leap_assert, leap_assert_type @@ -138,13 +137,6 @@ class LeapIncomingMail(object): # initialize a mail parser only once self._parser = Parser() - @property - def _pkey(self): - if sameProxiedObjects(self._keymanager, None): - logger.warning('tried to get key, but null keymanager found') - return None - return self._keymanager.get_key(self._userid, OpenPGPKey, private=True) - # # Public API: fetch, start_loop, stop. # @@ -312,40 +304,46 @@ class LeapIncomingMail(object): :param doc: A document containing an encrypted message. :type doc: SoledadDocument - :return: A tuple containing the document and the decrypted message. - :rtype: (SoledadDocument, str) + :return: A Deferred that will be fired with the document and the + decrypted message. + :rtype: SoledadDocument, str """ log.msg('decrypting msg') - success = False - try: - decrdata = self._keymanager.decrypt( - doc.content[ENC_JSON_KEY], - self._pkey) - success = True - except Exception as exc: - # XXX move this to errback !!! - logger.error("Error while decrypting msg: %r" % (exc,)) - decrdata = "" - leap_events.signal(IMAP_MSG_DECRYPTED, "1" if success else "0") + def process_decrypted(res): + if isinstance(res, tuple): + decrdata, _ = res + success = True + else: + decrdata = "" + success = False - data = self._process_decrypted_doc((doc, decrdata)) - return (doc, data) + leap_events.signal(IMAP_MSG_DECRYPTED, "1" if success else "0") - def _process_decrypted_doc(self, msgtuple): + data = self._process_decrypted_doc(doc, decrdata) + return doc, data + + d = self._keymanager.decrypt( + doc.content[ENC_JSON_KEY], + self._userid, OpenPGPKey) + d.addErrback(self._errback) + d.addCallback(process_decrypted) + return d + + def _process_decrypted_doc(self, doc, data): """ Process a document containing a succesfully decrypted message. - :param msgtuple: a tuple consisting of a SoledadDocument - instance containing the incoming message - and data, the json-encoded, decrypted content of the - incoming message - :type msgtuple: (SoledadDocument, str) + :param doc: the incoming message + :type doc: SoledadDocument + :param data: the json-encoded, decrypted content of the incoming + message + :type data: str + :return: the processed data. :rtype: str """ log.msg('processing decrypted doc') - doc, data = msgtuple # XXX turn this into an errBack for each one of # the deferreds that would process an individual document @@ -421,45 +419,40 @@ class LeapIncomingMail(object): encoding = get_email_charset(data) msg = self._parser.parsestr(data) - # try to obtain sender public key - senderPubkey = None fromHeader = msg.get('from', None) + senderAddress = None if (fromHeader is not None and (msg.get_content_type() == MULTIPART_ENCRYPTED or msg.get_content_type() == MULTIPART_SIGNED)): - _, senderAddress = parseaddr(fromHeader) - try: - senderPubkey = self._keymanager.get_key( - senderAddress, OpenPGPKey) - except keymanager_errors.KeyNotFound: - pass - - valid_sig = False # we will add a header saying if sig is valid - decrypt_multi = self._decrypt_multipart_encrypted_msg - decrypt_inline = self._maybe_decrypt_inline_encrypted_msg + senderAddress = parseaddr(fromHeader) + + def add_leap_header(decrmsg, signkey): + if (senderAddress is None or + isinstance(signkey, keymanager_errors.KeyNotFound)): + decrmsg.add_header( + self.LEAP_SIGNATURE_HEADER, + self.LEAP_SIGNATURE_COULD_NOT_VERIFY) + elif isinstance(signkey, keymanager_errors.InvalidSignature): + decrmsg.add_header( + self.LEAP_SIGNATURE_HEADER, + self.LEAP_SIGNATURE_INVALID) + else: + decrmsg.add_header( + self.LEAP_SIGNATURE_HEADER, + self.LEAP_SIGNATURE_VALID, + pubkey=signkey.key_id) + return decrmsg.as_string() if msg.get_content_type() == MULTIPART_ENCRYPTED: - decrmsg, valid_sig = decrypt_multi( - msg, encoding, senderPubkey) + d = self._decrypt_multipart_encrypted_msg( + msg, encoding, senderAddress) else: - decrmsg, valid_sig = decrypt_inline( - msg, encoding, senderPubkey) - - # add x-leap-signature header - if senderPubkey is None: - decrmsg.add_header( - self.LEAP_SIGNATURE_HEADER, - self.LEAP_SIGNATURE_COULD_NOT_VERIFY) - else: - decrmsg.add_header( - self.LEAP_SIGNATURE_HEADER, - self.LEAP_SIGNATURE_VALID if valid_sig else - self.LEAP_SIGNATURE_INVALID, - pubkey=senderPubkey.key_id) - - return decrmsg.as_string() + d = self._maybe_decrypt_inline_encrypted_msg( + msg, encoding, senderAddress) + d.addCallback(add_leap_header) + return d - def _decrypt_multipart_encrypted_msg(self, msg, encoding, senderPubkey): + def _decrypt_multipart_encrypted_msg(self, msg, encoding, senderAddress): """ Decrypt a message with content-type 'multipart/encrypted'. @@ -467,12 +460,13 @@ class LeapIncomingMail(object): :type msg: Message :param encoding: The encoding of the email message. :type encoding: str - :param senderPubkey: The key of the sender of the message. - :type senderPubkey: OpenPGPKey + :param senderAddress: The email address of the sender of the message. + :type senderAddress: str - :return: A tuple containing a decrypted message and - a bool indicating whether the signature is valid. - :rtype: (Message, bool) + :return: A Deferred that will be fired with a tuple containing a + decrypted Message and the signing OpenPGPKey if the signature + is valid or InvalidSignature or KeyNotFound. + :rtype: Deferred """ log.msg('decrypting multipart encrypted msg') msg = copy.deepcopy(msg) @@ -483,33 +477,33 @@ class LeapIncomingMail(object): encdata = pgpencmsg.get_payload() # decrypt or fail gracefully - try: - decrdata, valid_sig = self._decrypt_and_verify_data( - encdata, senderPubkey) - except keymanager_errors.DecryptError as e: - logger.warning('Failed to decrypt encrypted message (%s). ' - 'Storing message without modifications.' % str(e)) - # Bailing out! - return (msg, False) + def build_msg(res): + decrdata, signkey = res - decrmsg = self._parser.parsestr(decrdata) - # remove original message's multipart/encrypted content-type - del(msg['content-type']) + decrmsg = self._parser.parsestr(decrdata) + # remove original message's multipart/encrypted content-type + del(msg['content-type']) - # replace headers back in original message - for hkey, hval in decrmsg.items(): - try: - # this will raise KeyError if header is not present - msg.replace_header(hkey, hval) - except KeyError: - msg[hkey] = hval + # replace headers back in original message + for hkey, hval in decrmsg.items(): + try: + # this will raise KeyError if header is not present + msg.replace_header(hkey, hval) + except KeyError: + msg[hkey] = hval + + # all ok, replace payload by unencrypted payload + msg.set_payload(decrmsg.get_payload()) + return (msg, signkey) - # all ok, replace payload by unencrypted payload - msg.set_payload(decrmsg.get_payload()) - return (msg, valid_sig) + d = self._keymanager.decrypt( + encdata, self._userid, OpenPGPKey, + verify=senderAddress) + d.addCallbacks(build_msg, self._decryption_error, errbackArgs=(msg,)) + return d def _maybe_decrypt_inline_encrypted_msg(self, origmsg, encoding, - senderPubkey): + senderAddress): """ Possibly decrypt an inline OpenPGP encrypted message. @@ -517,12 +511,13 @@ class LeapIncomingMail(object): :type origmsg: Message :param encoding: The encoding of the email message. :type encoding: str - :param senderPubkey: The key of the sender of the message. - :type senderPubkey: OpenPGPKey + :param senderAddress: The email address of the sender of the message. + :type senderAddress: str - :return: A tuple containing a decrypted message and - a bool indicating whether the signature is valid. - :rtype: (Message, bool) + :return: A Deferred that will be fired with a tuple containing a + decrypted Message and the signing OpenPGPKey if the signature + is valid or InvalidSignature or KeyNotFound. + :rtype: Deferred """ log.msg('maybe decrypting inline encrypted msg') # serialize the original message @@ -530,54 +525,48 @@ class LeapIncomingMail(object): g = Generator(buf) g.flatten(origmsg) data = buf.getvalue() + + def decrypted_data(res): + decrdata, signkey = res + return data.replace(pgp_message, decrdata), signkey + + def encode_and_return(res): + data, signkey = res + if isinstance(data, unicode): + data = data.encode(encoding, 'replace') + return (self._parser.parsestr(data), signkey) + # handle exactly one inline PGP message - valid_sig = False if PGP_BEGIN in data: begin = data.find(PGP_BEGIN) end = data.find(PGP_END) pgp_message = data[begin:end + len(PGP_END)] - try: - decrdata, valid_sig = self._decrypt_and_verify_data( - pgp_message, senderPubkey) - # replace encrypted by decrypted content - data = data.replace(pgp_message, decrdata) - except keymanager_errors.DecryptError: - logger.warning('Failed to decrypt potential inline encrypted ' - 'message. Storing message as is...') - - # if message is not encrypted, return raw data - if isinstance(data, unicode): - data = data.encode(encoding, 'replace') - return (self._parser.parsestr(data), valid_sig) + d = self._keymanager.decrypt( + pgp_message, self._userid, OpenPGPKey, + verify=senderAddress) + d.addCallbacks(decrypted_data, self._decryption_error, + errbackArgs=(data,)) + else: + d = defer.succeed((data, None)) + d.addCallback(encode_and_return) + return d - def _decrypt_and_verify_data(self, data, senderPubkey): + def _decryption_error(self, failure, msg): """ - Decrypt C{data} using our private key and attempt to verify a - signature using C{senderPubkey}. - - :param data: The text to be decrypted. - :type data: unicode - :param senderPubkey: The public key of the sender of the message. - :type senderPubkey: OpenPGPKey - - :return: The decrypted data and a boolean stating whether the - signature could be verified. - :rtype: (str, bool) - - :raise DecryptError: Raised if failed to decrypt. + Check for known decryption errors """ - log.msg('decrypting and verifying data') - valid_sig = False - try: - decrdata = self._keymanager.decrypt( - data, self._pkey, - verify=senderPubkey) - if senderPubkey is not None: - valid_sig = True - except keymanager_errors.InvalidSignature: - decrdata = self._keymanager.decrypt( - data, self._pkey) - return (decrdata, valid_sig) + if failure.check(keymanager_errors.DecryptError): + logger.warning('Failed to decrypt encrypted message (%s). ' + 'Storing message without modifications.' + % str(failure.value)) + return (msg, None) + elif failure.check(keymanager_errors.KeyNotFound): + logger.error('Failed to find private key for decryption (%s). ' + 'Storing message without modifications.' + % str(failure.value)) + return (msg, None) + else: + return failure def _extract_keys(self, msgtuple): """ @@ -592,6 +581,10 @@ class LeapIncomingMail(object): and data, the json-encoded, decrypted content of the incoming message :type msgtuple: (SoledadDocument, str) + + :return: A Deferred that will be fired with msgtuple when key + extraction finishes + :rtype: Deferred """ OpenPGP_HEADER = 'OpenPGP' doc, data = msgtuple @@ -603,13 +596,17 @@ class LeapIncomingMail(object): _, fromAddress = parseaddr(msg['from']) header = msg.get(OpenPGP_HEADER, None) + dh = defer.success() if header is not None: - self._extract_openpgp_header(header, fromAddress) + dh = self._extract_openpgp_header(header, fromAddress) + da = defer.success() if msg.is_multipart(): - self._extract_attached_key(msg.get_payload(), fromAddress) + da = self._extract_attached_key(msg.get_payload(), fromAddress) - return msgtuple + d = defer.gatherResults([dh, da]) + d.addCallback(lambda _: msgtuple) + return d def _extract_openpgp_header(self, header, address): """ @@ -619,7 +616,11 @@ class LeapIncomingMail(object): :type header: str :param address: email address in the from header :type address: str + + :return: A Deferred that will be fired when header extraction is done + :rtype: Deferred """ + d = defer.success() fields = dict([f.strip(' ').split('=') for f in header.split(';')]) if 'url' in fields: url = shlex.split(fields['url'])[0] # remove quotations @@ -627,21 +628,28 @@ class LeapIncomingMail(object): addressHostname = address.split('@')[1] if (urlparts.scheme == 'https' and urlparts.hostname == addressHostname): - try: - self._keymanager.fetch_key(address, url, OpenPGPKey) - logger.info("Imported key from header %s" % (url,)) - except keymanager_errors.KeyNotFound: - logger.warning("Url from OpenPGP header %s failed" - % (url,)) - except keymanager_errors.KeyAttributesDiffer: - logger.warning("Key from OpenPGP header url %s didn't " - "match the from address %s" - % (url, address)) + def fetch_error(failure): + if failure.check(keymanager_errors.KeyNotFound): + logger.warning("Url from OpenPGP header %s failed" + % (url,)) + elif failure.check(keymanager_errors.KeyAttributesDiffer): + logger.warning("Key from OpenPGP header url %s didn't " + "match the from address %s" + % (url, address)) + else: + return failure + + d = self._keymanager.fetch_key(address, url, OpenPGPKey) + d.addCallback( + lambda _: + logger.info("Imported key from header %s" % (url,))) + d.addErrback(fetch_error) else: logger.debug("No valid url on OpenPGP header %s" % (url,)) else: logger.debug("There is no url on the OpenPGP header: %s" % (header,)) + return d def _extract_attached_key(self, attachments, address): """ @@ -651,16 +659,22 @@ class LeapIncomingMail(object): :type attachments: list(email.Message) :param address: email address in the from header :type address: str + + :return: A Deferred that will be fired when all the keys are stored + :rtype: Deferred """ MIME_KEY = "application/pgp-keys" + deferreds = [] for attachment in attachments: if MIME_KEY == attachment.get_content_type(): logger.debug("Add key from attachment") - self._keymanager.put_raw_key( + d = self._keymanager.put_raw_key( attachment.get_payload(), OpenPGPKey, address=address) + deferreds.append(d) + return defer.gatherResults(deferreds) def _add_message_locally(self, msgtuple): """ @@ -672,6 +686,9 @@ class LeapIncomingMail(object): and data, the json-encoded, decrypted content of the incoming message :type msgtuple: (SoledadDocument, str) + + :return: A Deferred that will be fired when the messages is stored + :rtype: Defferred """ doc, data = msgtuple log.msg('adding message %s to local db' % (doc.doc_id,)) @@ -690,6 +707,7 @@ class LeapIncomingMail(object): d = self._inbox.addMessage(data, flags=(self.RECENT_FLAG,), notify_on_disk=True) d.addCallbacks(msgSavedCallback, self._errback) + return d # # helpers |