class OTREncryption(object):
def __init__(self, stream):
self.stream = stream
self.otr_cache = OTRCache()
self.otr_session = OTRSession(
self.otr_cache.private_key, self.stream, supported_versions={
3
}) # we need at least OTR-v3 for question based SMP
notification_center = NotificationCenter()
notification_center.add_observer(self, sender=stream)
notification_center.add_observer(self, sender=self.otr_session)
@property
def active(self):
try:
return self.otr_session.encrypted
except AttributeError:
return False
@property
def cipher(self):
return 'AES-128-CTR' if self.active else None
@property
def key_fingerprint(self):
try:
return binascii.hexlify(self.otr_session.local_private_key.
public_key.fingerprint).decode()
except (AttributeError, TypeError):
return None
@property
def peer_fingerprint(self):
try:
return binascii.hexlify(
self.otr_session.remote_public_key.fingerprint).decode()
except (AttributeError, TypeError):
return None
@property
def peer_name(self):
try:
return self.__dict__['peer_name']
except KeyError:
trusted_peer = self.otr_cache.trusted_peers.get(
self.peer_fingerprint, None)
if trusted_peer is None:
return ''
else:
return self.__dict__.setdefault('peer_name',
trusted_peer.description)
@peer_name.setter
def peer_name(self, name):
old_name = self.peer_name
new_name = self.__dict__['peer_name'] = name
if old_name != new_name:
trusted_peer = self.otr_cache.trusted_peers.get(
self.peer_fingerprint, None)
if trusted_peer is not None:
trusted_peer.description = new_name
self.otr_cache.save()
notification_center = NotificationCenter()
notification_center.post_notification(
"ChatStreamOTRPeerNameChanged",
sender=self.stream,
data=NotificationData(name=name))
@property
def verified(self):
return self.peer_fingerprint in self.otr_cache.trusted_peers
@verified.setter
def verified(self, value):
peer_fingerprint = self.peer_fingerprint
old_verified = peer_fingerprint in self.otr_cache.trusted_peers
new_verified = bool(value)
if peer_fingerprint is None or new_verified == old_verified:
return
if new_verified:
self.otr_cache.trusted_peers.add(
OTRTrustedPeer(peer_fingerprint, description=self.peer_name))
else:
self.otr_cache.trusted_peers.remove(peer_fingerprint)
self.otr_cache.save()
notification_center = NotificationCenter()
notification_center.post_notification(
"ChatStreamOTRVerifiedStateChanged",
sender=self.stream,
data=NotificationData(verified=new_verified))
@run_in_twisted_thread
def start(self):
if self.otr_session is not None:
self.otr_session.start()
@run_in_twisted_thread
def stop(self):
if self.otr_session is not None:
self.otr_session.stop()
@run_in_twisted_thread
def smp_verify(self, secret, question=None):
self.otr_session.smp_verify(secret, question)
@run_in_twisted_thread
def smp_answer(self, secret):
self.otr_session.smp_answer(secret)
@run_in_twisted_thread
def smp_abort(self):
self.otr_session.smp_abort()
def handle_notification(self, notification):
handler = getattr(self, '_NH_%s' % notification.name, Null)
handler(notification)
def _NH_MediaStreamDidStart(self, notification):
if self.stream.start_otr:
self.otr_session.start()
def _NH_MediaStreamDidEnd(self, notification):
notification.center.remove_observer(self, sender=self.stream)
notification.center.remove_observer(self, sender=self.otr_session)
self.otr_session.stop()
self.otr_session = None
self.stream = None
_NH_MediaStreamDidNotInitialize = _NH_MediaStreamDidEnd
def _NH_OTRSessionStateChanged(self, notification):
notification.center.post_notification(
'ChatStreamOTREncryptionStateChanged',
sender=self.stream,
data=notification.data)
def _NH_OTRSessionSMPVerificationDidStart(self, notification):
notification.center.post_notification(
'ChatStreamSMPVerificationDidStart',
sender=self.stream,
data=notification.data)
def _NH_OTRSessionSMPVerificationDidNotStart(self, notification):
notification.center.post_notification(
'ChatStreamSMPVerificationDidNotStart',
sender=self.stream,
data=notification.data)
def _NH_OTRSessionSMPVerificationDidEnd(self, notification):
notification.center.post_notification(
'ChatStreamSMPVerificationDidEnd',
sender=self.stream,
data=notification.data)
class DataConnection(object):
implements(IObserver)
def __init__(self, name):
self.name = name
self.secret = None
self.private_key = DSAPrivateKey.generate()
self.otr_session = OTRSession(self.private_key, transport=self)
self.peer = None
self.send_queue = EventQueue(handler=self._send_handler)
self.send_queue.start()
self.ake_done = Event()
self.smp_done = Event()
self.all_done = Event()
self.otr_done = Event()
self.smp_status = None
self.same_secrets = None
self.sent_message = None
self.received_message = None
NotificationCenter().add_observer(self, sender=self.otr_session)
def _send_handler(self, message):
time.sleep(0.01)
self.peer.receive(message)
def connect(self, peer):
self.peer = peer
def disconnect(self):
self.send_queue.stop()
self.send_queue = None
def start_otr(self, secret=None):
self.secret = secret
self.otr_session.start()
def stop_otr(self):
self.otr_session.stop()
def inject_otr_message(self, message):
log.debug("{0.name} sending: {1!r}".format(self, message))
self.send_queue.put(message)
def send(self, content, content_type='text/plain'):
log.debug("{0.name} encoding: {1!r}".format(self, content))
self.sent_message = content
content = self.otr_session.handle_output(content, content_type)
log.debug("{0.name} sending: {1!r}".format(self, content))
self.send_queue.put(content)
def receive(self, message):
# log.debug("{0.name} received: {1!r}".format(self, message))
try:
message = self.otr_session.handle_input(message, 'text/plain')
except IgnoreMessage:
return
else:
log.debug("{0.name} decoded: {1!r}".format(self, message))
self.received_message = message
self.all_done.set()
def handle_notification(self, notification):
handler = getattr(self, '_NH_{0.name}'.format(notification), Null)
handler(notification)
def _NH_OTRSessionStateChanged(self, notification):
if notification.data.new_state is OTRState.Encrypted:
self.ake_done.set()
if self.secret is None:
self.smp_done.set()
elif self.name < self.peer.name:
self.otr_session.smp_verify(secret=self.secret)
elif notification.data.old_state is OTRState.Encrypted:
self.otr_done.set()
def _NH_OTRSessionSMPVerificationDidStart(self, notification):
if notification.data.originator == 'remote':
if self.secret:
self.otr_session.smp_answer(secret=self.secret)
else:
self.otr_session.smp_abort()
def _NH_OTRSessionSMPVerificationDidNotStart(self, notification):
self.smp_status = notification.data.reason
self.smp_done.set()
def _NH_OTRSessionSMPVerificationDidEnd(self, notification):
self.same_secrets = notification.data.same_secrets
self.smp_status = notification.data.status
self.smp_done.set()
class DataConnection(object):
implements(IObserver)
def __init__(self, name):
self.name = name
self.secret = None
self.private_key = DSAPrivateKey.generate()
self.otr_session = OTRSession(self.private_key, transport=self)
self.peer = None
self.send_queue = EventQueue(handler=self._send_handler)
self.send_queue.start()
self.ake_done = Event()
self.smp_done = Event()
self.all_done = Event()
self.otr_done = Event()
self.smp_status = None
self.same_secrets = None
self.sent_message = None
self.received_message = None
NotificationCenter().add_observer(self, sender=self.otr_session)
def _send_handler(self, message):
time.sleep(0.01)
self.peer.receive(message)
def connect(self, peer):
self.peer = peer
def disconnect(self):
self.send_queue.stop()
self.send_queue = None
def start_otr(self, secret=None):
self.secret = secret
self.otr_session.start()
def stop_otr(self):
self.otr_session.stop()
def inject_otr_message(self, message):
log.debug("{0.name} sending: {1!r}".format(self, message))
self.send_queue.put(message)
def send(self, content, content_type='text/plain'):
log.debug("{0.name} encoding: {1!r}".format(self, content))
self.sent_message = content
content = self.otr_session.handle_output(content, content_type)
log.debug("{0.name} sending: {1!r}".format(self, content))
self.send_queue.put(content)
def receive(self, message):
# log.debug("{0.name} received: {1!r}".format(self, message))
try:
message = self.otr_session.handle_input(message, 'text/plain')
except IgnoreMessage:
return
else:
log.debug("{0.name} decoded: {1!r}".format(self, message))
self.received_message = message
self.all_done.set()
def handle_notification(self, notification):
handler = getattr(self, '_NH_{0.name}'.format(notification), Null)
handler(notification)
def _NH_OTRSessionStateChanged(self, notification):
if notification.data.new_state is OTRState.Encrypted:
self.ake_done.set()
if self.secret is None:
self.smp_done.set()
elif self.name < self.peer.name:
self.otr_session.smp_verify(secret=self.secret)
elif notification.data.old_state is OTRState.Encrypted:
self.otr_done.set()
def _NH_OTRSessionSMPVerificationDidStart(self, notification):
if notification.data.originator == 'remote':
if self.secret:
self.otr_session.smp_answer(secret=self.secret)
else:
self.otr_session.smp_abort()
def _NH_OTRSessionSMPVerificationDidNotStart(self, notification):
self.smp_status = notification.data.reason
self.smp_done.set()
def _NH_OTRSessionSMPVerificationDidEnd(self, notification):
self.same_secrets = notification.data.same_secrets
self.smp_status = notification.data.status
self.smp_done.set()
class OTREncryption(object):
implements(IObserver)
def __init__(self, stream):
self.stream = stream
self.otr_cache = OTRCache()
self.otr_session = OTRSession(self.otr_cache.private_key, self.stream, supported_versions={3}) # we need at least OTR-v3 for question based SMP
notification_center = NotificationCenter()
notification_center.add_observer(self, sender=stream)
notification_center.add_observer(self, sender=self.otr_session)
@property
def active(self):
try:
return self.otr_session.encrypted
except AttributeError:
return False
@property
def cipher(self):
return 'AES-128-CTR' if self.active else None
@property
def key_fingerprint(self):
try:
return self.otr_session.local_private_key.public_key.fingerprint
except AttributeError:
return None
@property
def peer_fingerprint(self):
try:
return self.otr_session.remote_public_key.fingerprint
except AttributeError:
return None
@property
def peer_name(self):
try:
return self.__dict__['peer_name']
except KeyError:
trusted_peer = self.otr_cache.trusted_peers.get(self.peer_fingerprint, None)
if trusted_peer is None:
return u''
else:
return self.__dict__.setdefault('peer_name', trusted_peer.description)
@peer_name.setter
def peer_name(self, name):
old_name = self.peer_name
new_name = self.__dict__['peer_name'] = name
if old_name != new_name:
trusted_peer = self.otr_cache.trusted_peers.get(self.peer_fingerprint, None)
if trusted_peer is not None:
trusted_peer.description = new_name
self.otr_cache.save()
notification_center = NotificationCenter()
notification_center.post_notification("ChatStreamOTRPeerNameChanged", sender=self.stream, data=NotificationData(name=name))
@property
def verified(self):
return self.peer_fingerprint in self.otr_cache.trusted_peers
@verified.setter
def verified(self, value):
peer_fingerprint = self.peer_fingerprint
old_verified = peer_fingerprint in self.otr_cache.trusted_peers
new_verified = bool(value)
if peer_fingerprint is None or new_verified == old_verified:
return
if new_verified:
self.otr_cache.trusted_peers.add(OTRTrustedPeer(peer_fingerprint, description=self.peer_name))
else:
self.otr_cache.trusted_peers.remove(peer_fingerprint)
self.otr_cache.save()
notification_center = NotificationCenter()
notification_center.post_notification("ChatStreamOTRVerifiedStateChanged", sender=self.stream, data=NotificationData(verified=new_verified))
@run_in_twisted_thread
def start(self):
if self.otr_session is not None:
self.otr_session.start()
@run_in_twisted_thread
def stop(self):
if self.otr_session is not None:
self.otr_session.stop()
@run_in_twisted_thread
def smp_verify(self, secret, question=None):
self.otr_session.smp_verify(secret, question)
@run_in_twisted_thread
def smp_answer(self, secret):
self.otr_session.smp_answer(secret)
@run_in_twisted_thread
def smp_abort(self):
self.otr_session.smp_abort()
def handle_notification(self, notification):
handler = getattr(self, '_NH_%s' % notification.name, Null)
handler(notification)
def _NH_MediaStreamDidStart(self, notification):
if self.stream.start_otr:
self.otr_session.start()
def _NH_MediaStreamDidEnd(self, notification):
notification.center.remove_observer(self, sender=self.stream)
notification.center.remove_observer(self, sender=self.otr_session)
self.otr_session.stop()
self.otr_session = None
self.stream = None
_NH_MediaStreamDidNotInitialize = _NH_MediaStreamDidEnd
def _NH_OTRSessionStateChanged(self, notification):
notification.center.post_notification('ChatStreamOTREncryptionStateChanged', sender=self.stream, data=notification.data)
def _NH_OTRSessionSMPVerificationDidStart(self, notification):
notification.center.post_notification('ChatStreamSMPVerificationDidStart', sender=self.stream, data=notification.data)
def _NH_OTRSessionSMPVerificationDidNotStart(self, notification):
notification.center.post_notification('ChatStreamSMPVerificationDidNotStart', sender=self.stream, data=notification.data)
def _NH_OTRSessionSMPVerificationDidEnd(self, notification):
notification.center.post_notification('ChatStreamSMPVerificationDidEnd', sender=self.stream, data=notification.data)