Add the OTR plugin

1 files changed, 136 insertions, 0 deletions

diff --git a/plugins/otr.py b/plugins/otr.py
new file mode 100644
index 00000000..b674c0fd
--- /dev/null
+++ b/plugins/otr.py
@@ -0,0 +1,136 @@
+import pyotr
+from sleekxmpp.xmlstream.stanzabase import JID
+
+import logging
+log = logging.getLogger(__name__)
+
+from plugin import BasePlugin
+
+import tabs
+from tabs import ConversationTab
+
+class Plugin(BasePlugin):
+    def init(self):
+        self.contacts = {}
+        # a dict of {full-JID: OTR object}
+        self.add_event_handler('conversation_say_after', self.on_conversation_say)
+        self.add_event_handler('conversation_msg', self.on_conversation_msg)
+
+        self.add_command('otr', self.command_otr, "Usage: /otr <start|end>\notr: Start or stop OTR for the current conversation", self.otr_completion)
+        ConversationTab.add_information_element('otr', self.display_encryption_status)
+
+    def cleanup(self):
+        ConversationTab.remove_information_element('otr')
+        self.del_tab_command(ConversationTab, 'otr')
+
+    def otr_special(self, tab, typ):
+        def helper(msg):
+            tab.add_message('%s: %s' % (typ, msg.decode()))
+        return helper
+
+    def otr_on_state_change(self, tab):
+        def helper(old, new):
+            old = self.otr_state(old)
+            new = self.otr_state(new)
+            tab.add_message('OTR state has changed from %s to %s' % (old, new))
+        return helper
+
+    def get_otr(self, tab):
+        if tab not in self.contacts:
+            self.contacts[tab] = pyotr.OTR(on_error=self.otr_special(tab, 'Error'), on_warn=self.otr_special(tab, 'Warn'), on_state_change=self.otr_on_state_change(tab))
+        return self.contacts[tab]
+
+    def on_conversation_say(self, message, tab):
+        """
+        Feed the message through the OTR filter
+        """
+        to = message['to']
+        if not message['body']:
+            # there’s nothing to encrypt if this is a chatstate, for example
+            return
+        otr_state = self.get_otr(tab)
+        # Not sure what to do with xhtml bodies, and I don't like them anyway ;)
+        del message['xhtml_im']
+        say = otr_state.transform_msg(message['body'].encode())
+        if say is not None:
+            message['body'] = say.decode()
+        else:
+            del message['body']
+
+    def on_conversation_msg(self, message, tab):
+        """
+        Feed the message through the OTR filter
+        """
+        fro = message['from']
+        if not message['body']:
+            # there’s nothing to decrypt if this is a chatstate, for example
+            return
+        otr_state = self.get_otr(tab)
+        # Not sure what to do with xhtml bodies, and I don't like them anyway ;)
+        del message['xhtml_im']
+        display, reply = otr_state.handle_msg(message['body'].encode())
+        #self.core.information('D: {!r}, R: {!r}'.format(display, reply))
+        if display is not None:
+            message['body'] = display.decode()
+        else:
+            del message['body']
+        if reply is not None:
+            self.otr_say(tab, reply.decode())
+
+    @staticmethod
+    def otr_state(state):
+        if state == pyotr.MSG_STATE_PLAINTEXT:
+            return 'plaintext'
+        elif state == pyotr.MSG_STATE_ENCRYPTED:
+            return 'encrypted'
+        elif state == pyotr.MSG_STATE_FINISHED:
+            return 'finished'
+
+    def display_encryption_status(self, jid):
+        """
+        Returns the status of encryption for the associated jid. This is to be used
+        in the ConversationTab’s InfoWin.
+        """
+        tab = self.core.get_tab_by_name(jid, tabs.ConversationTab)
+        if tab not in self.contacts:
+            return ''
+        state = self.otr_state(self.contacts[tab].state)
+        return ' OTR: %s' % (state,)
+
+    def otr_say(self, tab, line):
+        msg = self.core.xmpp.make_message(tab.get_name())
+        msg['type'] = 'chat'
+        msg['body'] = line
+        msg.send()
+
+    def command_otr(self, args):
+        """
+        A command to start or end OTR encryption
+        """
+        args = args.split()
+        if not args:
+            return self.core.command_help("otr")
+        if isinstance(self.core.current_tab(), ConversationTab):
+            jid = JID(self.core.current_tab().get_name())
+        command = args[0]
+        if command == 'start':
+            otr_state = self.get_otr(self.core.current_tab())
+            self.otr_say(self.core.current_tab(), otr_state.start().decode())
+        elif command == 'end':
+            otr_state = self.get_otr(self.core.current_tab())
+            msg = otr_state.end()
+            if msg is not None:
+                self.otr_say(self.core.current_tab(), msg.decode())
+        elif command == 'fpr':
+            otr_state = self.get_otr(self.core.current_tab())
+            our = otr_state.our_fpr
+            if our:
+                our = hex(int.from_bytes(our, 'big'))[2:].ljust(40).upper()
+            their = otr_state.their_fpr
+            if their:
+                their = hex(int.from_bytes(their, 'big'))[2:].ljust(40).upper()
+            self.core.current_tab().add_message('Your: %s Their: %s' % (our, their))
+        self.core.refresh_window()
+
+    def otr_completion(self, the_input):
+        return the_input.auto_completion(['start', 'end'], ' ')