Add support for XEP-0380: Explicit Message Encryption

Both for displaying incoming messages, and sending OTR and legacy
OpenPGP.

plugins/gpg/__init__.py

@@ -251,6 +251,7 @@ class Plugin(BasePlugin):
             encrypted_element.text = self.remove_gpg_headers(xml.sax.saxutils.escape(str(text)))
             message.append(encrypted_element)
             message['body'] = 'This message has been encrypted using the GPG key with id: %s' % self.keyid
+            message['eme']['namespace'] = 'jabber:x:encrypted'
             message.send()
             del message['body']
             tab.add_message(body, nickname=self.core.own_nick,

plugins/otr.py

@@ -347,6 +347,7 @@ class PoezioContext(Context):
         message = self.xmpp.make_message(mto=self.peer,
                                          mbody=msg.decode('ascii'),
                                          mtype='chat')
+        message['eme']['namespace'] = 'urn:xmpp:otr:0'
         message.enable('carbon_private')
         message.enable('no-copy')
         message.enable('no-permanent-store')

poezio/connection.py

@@ -161,6 +161,7 @@ class Connection(slixmpp.ClientXMPP):
         self.register_plugin('xep_0319')
         self.register_plugin('xep_0334')
         self.register_plugin('xep_0352')
+        self.register_plugin('xep_0380')
         self.init_plugins()
 
     def set_keepalive_values(self, option=None, value=None):

poezio/core/handlers.py

@@ -259,7 +259,10 @@ class HandlerCore:
                                                   tmp_dir=tmp_dir,
                                                   extract_images=extract_images)
         if not body:
-            return
+            if not self.core.xmpp.plugin['xep_0380'].has_eme(message):
+                return
+            self.core.xmpp.plugin['xep_0380'].replace_body_with_eme(message)
+            body = msg['body']
 
         remote_nick = ''
         # normal message, we are the recipient