esession bugfixes

src/chat_control.py

@@ -971,6 +971,9 @@ class ChatControl(ChatControlBase):
 
 		self.session = session
 
+		# does this window have an existing, active esession?
+		self.esessioned = False
+
 		self.status_tooltip = gtk.Tooltips()
 		self.update_ui()
 		# restore previous conversation
@@ -1236,13 +1239,13 @@ class ChatControl(ChatControlBase):
 
 		contact = self.contact
 
+		encrypted = bool(self.session) and self.session.enable_encryption
+
 		keyID = ''
-		encrypted = False
 		if self.xml.get_widget('gpg_togglebutton').get_active():
 			keyID = contact.keyID
 			encrypted = True
 
-
 		chatstates_on = gajim.config.get('outgoing_chat_state_notifications') != \
 			'disabled'
 		composing_jep = contact.composing_jep
@@ -1352,18 +1355,46 @@ class ChatControl(ChatControlBase):
 			kind = 'info'
 			name = ''
 		else:
-			ec = gajim.encrypted_chats[self.account]
+			# ESessions
-			if encrypted and jid not in ec:
+			if self.session.enable_encryption:
-				msg = _('Encryption enabled')
+				if not self.esessioned:
+					msg = _('Encryption enabled')
+					ChatControlBase.print_conversation_line(self, msg, 
+						'status', '', tim)
+
+					if self.session.loggable:
+						msg = _('Session WILL be logged')
+					else:
+						msg = _('Session WILL NOT be logged')
+
+					ChatControlBase.print_conversation_line(self, msg, 
+						'status', '', tim)
+
+					self.esessioned = True
+				elif not encrypted:
+					msg = _('The following message was NOT encrypted')
+					ChatControlBase.print_conversation_line(self, msg, 
+						'status', '', tim)
+			elif self.esessioned:
+				msg = _('Encryption disabled')
 				ChatControlBase.print_conversation_line(self, msg, 
 					'status', '', tim)
-				ec.append(jid)
+				self.esessioned = False
-			elif not encrypted and jid in ec:
+			else:
-				msg = _('Encryption disabled')
+				# GPG encryption
-				ChatControlBase.print_conversation_line(self, msg,
+				ec = gajim.encrypted_chats[self.account]
-					'status', '', tim)
+				if encrypted and jid not in ec:
-				ec.remove(jid)
+					msg = _('Encryption enabled')
-			self.xml.get_widget('gpg_togglebutton').set_active(encrypted)
+					ChatControlBase.print_conversation_line(self, msg, 
+						'status', '', tim)
+					ec.append(jid)
+				elif not encrypted and jid in ec:
+					msg = _('Encryption disabled')
+					ChatControlBase.print_conversation_line(self, msg,
+						'status', '', tim)
+					ec.remove(jid)
+				self.xml.get_widget('gpg_togglebutton').set_active(encrypted)
+
 			if not frm:
 				kind = 'incoming'
 				name = contact.get_shown_name()
@@ -1949,9 +1980,15 @@ class ChatControl(ChatControlBase):
 		if self.session and self.session.enable_encryption:
 			self.session.terminate_e2e()
 
+			msg = _('Encryption disabled')
+			ChatControlBase.print_conversation_line(self, msg, 
+				'status', '', None)
+			self.esessioned = False
+
 			jid = str(self.session.jid)
 
 			gajim.connections[self.account].delete_session(jid, self.session.thread_id)
+
 			self.session = gajim.connections[self.account].make_new_session(jid)
 		else:
 			if not self.session:

src/common/connection_handlers.py

@@ -1451,18 +1451,22 @@ class ConnectionHandlers(ConnectionVcard, ConnectionBytestream, ConnectionDisco,
 			self._InitE2ECB(con, msg, session)
 		
 		encrypted = False
+		tim = msg.getTimestamp()
+		tim = time.strptime(tim, '%Y%m%dT%H:%M:%S')
+		tim = time.localtime(timegm(tim))
 
-		e2eTag = msg.getTag('c', namespace = common.xmpp.NS_STANZA_CRYPTO)
+		e2e_tag = msg.getTag('c', namespace = common.xmpp.NS_STANZA_CRYPTO)
-		if e2eTag:
+		if e2e_tag:
 			encrypted = True
-			msg = session.decrypt_stanza(msg)
+
+			try:
+				msg = session.decrypt_stanza(msg)
+			except:
+				self.dispatch('FAILED_DECRYPT', (frm, tim))
 
 		msgtxt = msg.getBody()
 		msghtml = msg.getXHTML()
 		subject = msg.getSubject() # if not there, it's None
-		tim = msg.getTimestamp()
-		tim = time.strptime(tim, '%Y%m%dT%H:%M:%S')
-		tim = time.localtime(timegm(tim))
 		jid = helpers.get_jid_from_iq(msg)
 		chatstate = None
 		encTag = msg.getTag('x', namespace = common.xmpp.NS_ENCRYPTED)
@@ -1573,6 +1577,8 @@ class ConnectionHandlers(ConnectionVcard, ConnectionBytestream, ConnectionDisco,
 
 	def get_session(self, jid, thread_id, type):
 		'''returns an existing session between this connection and 'jid', returns a new one if none exist.'''
+		print repr(self.sessions)
+
 		session = self.find_session(jid, thread_id, type)
 
 		if session:

src/common/stanza_session.py

@@ -289,7 +289,7 @@ class EncryptedStanzaSession(StanzaSession):
 		calculated_mac = self.hmac(self.km_o, macable + self.encode_mpi_with_padding(self.c_o))
 
 		if not calculated_mac == received_mac:
-			raise 'bad signature (%s != %s)' % (repr(received_mac), repr(calculated_mac))
+			raise exceptions.DecryptionError, 'bad signature'
 
 		m_final = base64.b64decode(c.getTagData('data'))
 		m_compressed = self.decrypt(m_final)
@@ -298,7 +298,7 @@ class EncryptedStanzaSession(StanzaSession):
 		try:
 			parsed = xmpp.Node(node='<node>' + plaintext + '</node>')
 		except:
-			raise exceptions.DecryptionError
+			raise exceptions.DecryptionError, 'decrypted <data/> not parseable as XML'
 
 		for child in parsed.getChildren():
 			stanza.addChild(node=child)
@@ -377,12 +377,12 @@ class EncryptedStanzaSession(StanzaSession):
 			content += self.form_o + form_o2
 
 		mac_o_calculated = self.hmac(self.ks_o, content)
-		
+	
 		if self.negotiated['recv_pubkey']:
 			hash = self.sha256(mac_o_calculated)
 
 			if not eir_pubkey.verify(hash, signature):
-				raise exceptions.NegotiationError, 'public key signature verification failed!'
+				raise exceptions.NegotiationError, 'public key signature verification failed!' 
 
 		elif mac_o_calculated != mac_o:
 			raise exceptions.NegotiationError, 'calculated mac_%s differs from received mac_%s' % (i_o, i_o)
@@ -589,7 +589,7 @@ class EncryptedStanzaSession(StanzaSession):
 		self.n_o = base64.b64decode(form['my_nonce'])
 
 		dhhashes = form.getField('dhhashes').getValues()
-		self.He = base64.b64decode(dhhashes[group_order].encode("utf8"))
+		self.negotiated['He'] = base64.b64decode(dhhashes[group_order].encode("utf8"))
 
 		bytes = int(self.n / 8)
 
@@ -741,7 +741,8 @@ class EncryptedStanzaSession(StanzaSession):
 		e = self.decode_mpi(base64.b64decode(form['dhkeys']))
 		p = dh.primes[self.modp]
 
-		# XXX return <feature-not-implemented> if hash(e) != He
+		if self.sha256(self.encode_mpi(e)) != self.negotiated['He']:
+			raise exceptions.NegotiationError, 'SHA256(e) != He'
 
 		k = self.get_shared_secret(e, self.y, p)
 
@@ -903,10 +904,17 @@ class EncryptedStanzaSession(StanzaSession):
 
 	def fail_bad_negotiation(self, reason):
 		'''they've tried to feed us a bogus value, send an error and cancel everything.'''
+
 		err = xmpp.Error(xmpp.Message(), xmpp.ERR_FEATURE_NOT_IMPLEMENTED)
 		err.T.error.T.text.setData(reason)
 		self.send(err)
+
 		self.status = None
+		self.enable_encryption = False
+
+		# this prevents the MAC check on decryption from succeeding,
+		# preventing falsified messages from going through.
+		self.km_o = ''
 
 	def is_loggable(self):
 		account = self.conn.name

src/gajim.py

@@ -1701,6 +1701,15 @@ class Interface:
 		atom_entry, = data
 		AtomWindow.newAtomEntry(atom_entry)
 
+	def handle_event_failed_decrypt(self, account, data):
+		jid, tim = data
+
+		ctrl = self.msg_win_mgr.get_control(jid, account)
+		if ctrl:
+			ctrl.print_conversation_line('Unable to decrypt message from %s\nIt may have been tampered with.' % (jid), 'status', '', tim)
+		else:
+			print 'failed decrypt, unable to find a control to notify you in.'
+
 	def handle_session_negotiation(self, account, data):
 		jid, session, form = data
 
@@ -1713,12 +1722,25 @@ class Interface:
 		# encrypted session states. these are described in stanza_session.py
 
 		# bob responds
-		if form.getType() == 'form' and u'e2e' in \
+		if form.getType() == 'form' and 'security' in form.asDict():
-		map(lambda x: x[1], form.getField('security').getOptions()):
 			def continue_with_negotiation(*args):
 				if len(args):
 					self.dialog.destroy()
 
+				# we don't support 3-message negotiation as the responder
+				if 'dhkeys' in form.asDict():
+					err = xmpp.Error(xmpp.Message(), xmpp.ERR_FEATURE_NOT_IMPLEMENTED)
+
+					feature = xmpp.Node(xmpp.NS_FEATURE + ' feature')
+					field = xmpp.Node('field')
+					field['var'] = 'dhkeys'
+					
+					feature.addChild(node=field)
+					err.addChild(node=feature)
+
+					session.send(err)
+					return
+
 				negotiated, not_acceptable, ask_user = session.verify_options_bob(form)
 
 				if ask_user:
@@ -1776,8 +1798,11 @@ class Interface:
 					dialog.destroy()
 
 					negotiated.update(ask_user)
-				
+		
-					session.accept_e2e_alice(form, negotiated)
+					try:
+						session.accept_e2e_alice(form, negotiated)
+					except exceptions.NegotiationError, details:
+						session.fail_bad_negotiation(details)
 
 				def reject_nondefault_options(widget):
 					session.reject_negotiation()
@@ -1788,7 +1813,10 @@ class Interface:
 						on_response_yes = accept_nondefault_options,
 						on_response_no = reject_nondefault_options)
 			else:
-				session.accept_e2e_alice(form, negotiated)
+				try:
+					session.accept_e2e_alice(form, negotiated)
+				except exceptions.NegotiationError, details: 
+					session.fail_bad_negotiation(details)
 
 			return
 		elif session.status == 'responded-e2e' and form.getType() == 'result':
@@ -1802,7 +1830,7 @@ class Interface:
 			return
 		elif session.status == 'identified-alice' and form.getType() == 'result':
 			session.check_identity = lambda: negotiation.show_sas_dialog(jid, session.sas)
-
+			
 			try:
 				session.final_steps_alice(form)
 			except exceptions.NegotiationError, details: 
@@ -1819,7 +1847,7 @@ class Interface:
 				ctrl = gajim.interface.msg_win_mgr.get_control(str(jid), account)
 
 				if ctrl:
-					ctrl.session = gajim.connections[self.account].make_new_session(str(jid))
+					ctrl.session = gajim.connections[account].make_new_session(str(jid))
 
 				return
 
@@ -2266,6 +2294,7 @@ class Interface:
 			'SIGNED_IN': self.handle_event_signed_in,
 			'METACONTACTS': self.handle_event_metacontacts,
 			'ATOM_ENTRY': self.handle_atom_entry,
+			'FAILED_DECRYPT': self.handle_event_failed_decrypt,
 			'PRIVACY_LISTS_RECEIVED': self.handle_event_privacy_lists_received,
 			'PRIVACY_LIST_RECEIVED': self.handle_event_privacy_list_received,
 			'PRIVACY_LISTS_ACTIVE_DEFAULT': \