def parse(self, message, nofragment=False):
otrTagPos = message.find(proto.OTRTAG)
if otrTagPos == -1:
if proto.MESSAGE_TAG_BASE in message:
return proto.TaggedPlaintext.parse(message)
else:
return message
indexBase = otrTagPos + len(proto.OTRTAG)
if len(message) <= indexBase:
return message
compare = message[indexBase]
if nofragment is False and compare == b','[0]:
message = self.fragmentAccumulate(message[indexBase:])
if message is None:
return None
else:
return self.parse(message, nofragment=True)
else:
self.discardFragment()
queryPayload = self.parseExplicitQuery(message)
if queryPayload is not None:
return proto.Query.parse(queryPayload)
if compare == b':'[0] and len(message) > indexBase + 4:
try:
infoTag = base64.b64decode(message[indexBase + 1:indexBase +
5])
classInfo = struct.unpack(b'!HB', infoTag)
cls = proto.messageClasses.get(classInfo, None)
if cls is None:
return message
logger.debug('{user} got msg {typ!r}' \
.format(user=self.user.name, typ=cls))
return cls.parsePayload(message[indexBase + 5:])
except (TypeError, struct.error):
logger.exception('could not parse OTR message %s', message)
return message
if message[indexBase:indexBase + 7] == b' Error:':
return proto.Error(message[indexBase + 7:])
return message
def receiveMessage(self, messageData, appdata=None):
IGN = None, []
if not self.policyOtrEnabled():
raise NotOTRMessage(messageData)
message = self.parse(messageData)
if message is None:
# nothing to see. move along.
return IGN
logger.debug(repr(message))
if self.getPolicy('SEND_TAG'):
if isinstance(message, basestring):
# received a plaintext message without tag
# we should not tag anymore
self.tagOffer = OFFER_REJECTED
else:
# got something OTR-ish, cool!
self.tagOffer = OFFER_ACCEPTED
if isinstance(message, proto.Query):
self.handleQuery(message, appdata=appdata)
if isinstance(message, proto.TaggedPlaintext):
# it's actually a plaintext message
if self.state != STATE_PLAINTEXT or \
self.getPolicy('REQUIRE_ENCRYPTION'):
# but we don't want plaintexts
raise UnencryptedMessage(message.msg)
raise NotOTRMessage(message.msg)
return IGN
if isinstance(message, proto.AKEMessage):
self.crypto.handleAKE(message, appdata=appdata)
return IGN
if isinstance(message, proto.DataMessage):
ignore = message.flags & proto.MSGFLAGS_IGNORE_UNREADABLE
if self.state != STATE_ENCRYPTED:
self.sendInternal(proto.Error(
'You sent encrypted data, but I wasn\'t expecting it.'
.encode('utf-8')), appdata=appdata)
if ignore:
return IGN
raise NotEncryptedError(EXC_UNREADABLE_MESSAGE)
try:
plaintext, tlvs = self.crypto.handleDataMessage(message)
self.processTLVs(tlvs, appdata=appdata)
if plaintext and self.lastSend < time() - HEARTBEAT_INTERVAL:
self.sendInternal(b'', appdata=appdata)
return plaintext or None, tlvs
except crypt.InvalidParameterError:
if ignore:
return IGN
logger.exception('decryption failed')
raise
if isinstance(message, basestring):
if self.state != STATE_PLAINTEXT or \
self.getPolicy('REQUIRE_ENCRYPTION'):
raise UnencryptedMessage(message)
if isinstance(message, proto.Error):
raise ErrorReceived(message)
raise NotOTRMessage(messageData)