Add Encryption Plugin API

- Add extension points when receiving/sending a message
- Add extension point for setting the lock image
- Add extension point after clicking the send button
- Add extension point when typing
- Add a new menu button to choose the desired encryption
- Extend the PluginManager to hold a list of encryption plugins

9 files changed, 134 insertions, 2 deletions

diff --git a/src/chat_control.py b/src/chat_control.py
index 83eecc57f..0fb0706b2 100644
--- a/src/chat_control.py
+++ b/src/chat_control.py
@@ -94,6 +94,7 @@ class ChatControl(ChatControlBase):
         self.last_recv_message_id = None
         self.last_recv_message_marks = None
         self.last_message_timestamp = None
+
         # for muc use:
         # widget = self.xml.get_object('muc_window_actions_button')
         self.actions_button = self.xml.get_object('message_window_actions_button')
@@ -302,6 +303,11 @@ class ChatControl(ChatControlBase):
                 True)
 
         self.update_ui()
+        self.set_lock_image()
+
+        self.encryption_menu = self.xml.get_object('encryption_menu')
+        self.encryption_menu.set_menu_model(
+            gui_menu_builder.get_encryption_menu(self.contact))
         # restore previous conversation
         self.restore_conversation()
         self.msg_textview.grab_focus()
@@ -907,6 +913,21 @@ class ChatControl(ChatControlBase):
         self._show_lock_image(self.gpg_is_active, 'OpenPGP',
                 self.gpg_is_active, loggable, True)
 
+    def set_lock_image(self):
+        visible = self.encryption != 'disabled'
+        loggable = self.session and self.session.is_loggable()
+
+        encryption_state = {'visible': visible,
+                            'enc_type': self.encryption,
+                            'enc_enabled': False,
+                            'chat_logged': loggable,
+                            'authenticated': False}
+
+        gajim.plugin_manager.gui_extension_point(
+            'encryption_state' + self.encryption, self, encryption_state)
+
+        self._show_lock_image(**encryption_state)
+ 
     def _show_lock_image(self, visible, enc_type='', enc_enabled=False,
                     chat_logged=False, authenticated=False):
         """
@@ -940,6 +961,8 @@ class ChatControl(ChatControlBase):
         self.lock_image.set_sensitive(enc_enabled)
 
     def _on_authentication_button_clicked(self, widget):
+        gajim.plugin_manager.gui_extension_point(
+            'encryption_dialog' + self.encryption, self)
         if self.gpg_is_active:
             dialogs.GPGInfoWindow(self, self.parent_win.window)
         elif self.session and self.session.enable_encryption:
@@ -950,6 +973,14 @@ class ChatControl(ChatControlBase):
         """
         Send a message to contact
         """
+
+        if self.encryption:
+            self.sendmessage = True
+            gajim.plugin_manager.gui_extension_point(
+                    'send_message' + self.encryption, self)
+            if not self.sendmessage:
+                return
+
         message = helpers.remove_invalid_xml_chars(message)
         if message in ('', None, '\n'):
             return None
@@ -1481,6 +1512,8 @@ class ChatControl(ChatControlBase):
     def _on_message_tv_buffer_changed(self, textbuffer):
         super()._on_message_tv_buffer_changed(textbuffer)
         if textbuffer.get_char_count():
+            gajim.plugin_manager.gui_extension_point(
+                'typing' + self.encryption, self)
             e2e_is_active = self.session and \
                     self.session.enable_encryption
             e2e_pref = gajim.config.get_per('accounts', self.account,
diff --git a/src/chat_control_base.py b/src/chat_control_base.py
index a81533b6a..248d4990f 100644
--- a/src/chat_control_base.py
+++ b/src/chat_control_base.py
@@ -34,6 +34,7 @@ from gi.repository import Gdk
 from gi.repository import Pango
 from gi.repository import GObject
 from gi.repository import GLib
+from gi.repository import Gio
 import gtkgui_helpers
 import message_control
 import dialogs
@@ -395,6 +396,10 @@ class ChatControlBase(MessageControl, ChatCommandProcessor, CommandTools):
                 self._on_window_motion_notify)
             self.handlers[id_] = parent_win.window
 
+        self.encryption = 'disabled'
+        self.set_encryption_state()
+        self.add_window_actions()
+
         # PluginSystem: adding GUI extension point for ChatControlBase
         # instance object (also subclasses, eg. ChatControl or GroupchatControl)
         gajim.plugin_manager.gui_extension_point('chat_control_base', self)
@@ -412,6 +417,38 @@ class ChatControlBase(MessageControl, ChatCommandProcessor, CommandTools):
         # to properly use the super, because of the old code.
         CommandTools.__init__(self)
 
+    def add_window_actions(self):
+        action = Gio.SimpleAction.new_stateful(
+            "%s-encryptiongroup" % self.contact.jid,
+            GLib.VariantType.new("s"),
+            GLib.Variant("s", self.encryption))
+        action.connect("change-state", self.activate_encryption)
+        self.parent_win.window.add_action(action)
+
+    def activate_encryption(self, action, param):
+        encryption = param.get_string()
+        if self.encryption == encryption:
+            return
+
+        if encryption != 'disabled':
+            plugin = gajim.plugin_manager.encryption_plugins[encryption]
+            if not plugin.activate_encryption(self):
+                return
+        action.set_state(param)
+        gajim.config.set_per(
+            'contacts', self.contact.jid, 'encryption', encryption)
+        self.encryption = encryption
+        self.set_lock_image()
+
+    def set_encryption_state(self):
+        enc = gajim.config.get_per('contacts', self.contact.jid, 'encryption')
+        if enc not in gajim.plugin_manager.encryption_plugins:
+            self.encryption = 'disabled'
+            gajim.config.set_per(
+                'contacts', self.contact.jid, 'encryption', 'disabled')
+        else:
+            self.encryption = enc
+
     def set_speller(self):
         # now set the one the user selected
         per_type = 'contacts'
@@ -723,7 +760,8 @@ class ChatControlBase(MessageControl, ChatCommandProcessor, CommandTools):
             keyID=keyID, type_=type_, chatstate=chatstate, msg_id=msg_id,
             resource=resource, user_nick=self.user_nick, xhtml=xhtml,
             label=label, callback=_cb, callback_args=[callback] + callback_args,
-            control=self, attention=attention, correction_msg=correction_msg, automatic_message=False))
+            control=self, attention=attention, correction_msg=correction_msg,
+            automatic_message=False, encryption=self.encryption))
 
         # Record the history of sent messages
         self.save_message(message, 'sent')
diff --git a/src/common/config.py b/src/common/config.py
index 3411bbb4c..f0c1aecb0 100644
--- a/src/common/config.py
+++ b/src/common/config.py
@@ -481,6 +481,7 @@ class Config:
             }, {}),
             'contacts': ({
                     'gpg_enabled': [ opt_bool, False, _('Is OpenPGP enabled for this contact?')],
+                    'encryption': [ opt_str, '', _('Encryption used for this contact.')],
                     'autonegotiate_esessions': [opt_bool, False, _('Should Gajim automatically start an encrypted session with this contact when possible?')],
                     'speller_language': [ opt_str, '', _('Language for which we want to check misspelled words')],
             }, {}),
diff --git a/src/common/connection.py b/src/common/connection.py
index efc77bba9..36104e34a 100644
--- a/src/common/connection.py
+++ b/src/common/connection.py
@@ -499,7 +499,7 @@ class CommonConnection:
 
         self._push_stanza_message_outgoing(obj, msg_iq)
 
-    def _push_stanza_message_outgoing(self, obj, msg_iq):    
+    def _push_stanza_message_outgoing(self, obj, msg_iq):
         obj.conn = self
         if isinstance(msg_iq, list):
             for iq in msg_iq:
@@ -2136,6 +2136,14 @@ class Connection(CommonConnection, ConnectionHandlers):
     def _nec_stanza_message_outgoing(self, obj):
         if obj.conn.name != self.name:
             return
+        encryption = gajim.config.get_per('contacts', obj.jid, 'encryption')
+        if encryption != 'disabled':
+            gajim.plugin_manager.gui_extension_point(
+                'encrypt' + encryption, self, obj, self.send_message)
+        else:
+            self.send_message(obj)
+
+    def send_message(self, obj):
         obj.msg_id = self.connection.send(obj.msg_iq, now=obj.now)
 
         gajim.nec.push_incoming_event(MessageSentEvent(
diff --git a/src/common/connection_handlers.py b/src/common/connection_handlers.py
index 7252f9046..2c45ec661 100644
--- a/src/common/connection_handlers.py
+++ b/src/common/connection_handlers.py
@@ -1091,6 +1091,12 @@ class ConnectionHandlersBase:
     def _nec_message_received(self, obj):
         if obj.conn.name != self.name:
             return
+
+        gajim.plugin_manager.gui_extension_point(
+            'decrypt', self, obj, self._on_message_received)
+        if not obj.encrypted:
+            self._on_message_received(obj)
+
         if obj.encrypted == 'xep200':
             try:
                 obj.stanza = obj.session.decrypt_stanza(obj.stanza)
@@ -1153,6 +1159,14 @@ class ConnectionHandlersBase:
         gajim.nec.push_incoming_event(MamDecryptedMessageReceivedEvent(None,
             conn=self, msg_obj=obj))
 
+    def _on_message_received(self, obj):
+        if isinstance(obj, MessageReceivedEvent):
+            gajim.nec.push_incoming_event(
+                DecryptedMessageReceivedEvent(None, conn=self, msg_obj=obj))
+        else:
+            gajim.nec.push_incoming_event(
+                MamDecryptedMessageReceivedEvent(None, conn=self, msg_obj=obj))
+
     def _nec_decrypted_message_received(self, obj):
         if obj.conn.name != self.name:
             return
diff --git a/src/common/connection_handlers_events.py b/src/common/connection_handlers_events.py
index 286f935fb..f5489600b 100644
--- a/src/common/connection_handlers_events.py
+++ b/src/common/connection_handlers_events.py
@@ -2796,6 +2796,7 @@ class MessageOutgoingEvent(nec.NetworkOutgoingEvent):
         self.attention = False
         self.correction_msg = None
         self.automatic_message = True
+        self.encryption = ''
 
     def get_full_jid(self):
         if self.resource:
diff --git a/src/gui_menu_builder.py b/src/gui_menu_builder.py
index 835b78578..6db2a8bb1 100644
--- a/src/gui_menu_builder.py
+++ b/src/gui_menu_builder.py
@@ -781,3 +781,14 @@ def build_bookmark_menu(account):
     label = menu.get_item_attribute_value(1, 'label').get_string()
     menu.remove(1)
     menu.insert_submenu(1, label, bookmark_menu)
+
+
+def get_encryption_menu(contact):
+    menu = Gio.Menu()
+    menu.append(
+        'Disabled', 'win.{}-encryptiongroup::{}'.format(contact.jid, 'disabled'))
+    for encryption in gajim.plugin_manager.encryption_plugins:
+        menu_action = 'win.{}-encryptiongroup::{}'.format(
+            contact.jid, encryption)
+        menu.append(encryption, menu_action)
+    return menu
diff --git a/src/plugins/gajimplugin.py b/src/plugins/gajimplugin.py
index 2a78e4977..18a8a75b0 100644
--- a/src/plugins/gajimplugin.py
+++ b/src/plugins/gajimplugin.py
@@ -59,6 +59,16 @@ class GajimPlugin(object):
     :todo: decide whether we really need this one, because class name (with
             module name) can act as such short name
     '''
+    encryption_name = ''
+    '''
+    Name of the encryption scheme.
+
+    The name that Gajim displays in the encryption menu.
+    Leave empty if the plugin is not an encryption plugin.
+
+    :type: str
+
+    '''
     version = ''
     '''
     Version of plugin.
diff --git a/src/plugins/pluginmanager.py b/src/plugins/pluginmanager.py
index eeeafcb04..dc7e867eb 100644
--- a/src/plugins/pluginmanager.py
+++ b/src/plugins/pluginmanager.py
@@ -101,6 +101,12 @@ class PluginManager(metaclass=Singleton):
         '''
         Registered handlers of GUI extension points.
         '''
+
+        self.encryption_plugins = {}
+        '''
+        Registered names with instances of encryption Plugins.
+        '''
+
         for path in [gajim.PLUGINS_DIRS[1], gajim.PLUGINS_DIRS[0]]:
             pc = PluginManager.scan_dir_for_plugins(path)
             self.add_plugins(pc)
@@ -291,6 +297,10 @@ class PluginManager(metaclass=Singleton):
             elif issubclass(event_class, nec.NetworkOutgoingEvent):
                 gajim.nec.unregister_outgoing_event(event_class)
 
+    def _remove_name_from_encryption_plugins(self, plugin):
+        if plugin.encryption_name:
+            del self.encryption_plugins[plugin.encryption_name]
+
     @log_calls('PluginManager')
     def activate_plugin(self, plugin):
         '''
@@ -300,6 +310,7 @@ class PluginManager(metaclass=Singleton):
         if not plugin.active and plugin.activatable:
 
             self._add_gui_extension_points_handlers_from_plugin(plugin)
+            self._add_encryption_name_from_plugin(plugin)
             self._handle_all_gui_extension_points_with_plugin(plugin)
             self._register_events_handlers_in_ged(plugin)
             self._register_network_events_in_nec(plugin)
@@ -339,6 +350,7 @@ class PluginManager(metaclass=Singleton):
 
         self._remove_events_handler_from_ged(plugin)
         self._remove_network_events_from_nec(plugin)
+        self._remove_name_from_encryption_plugins(plugin)
 
         # removing plug-in from active plug-ins list
         plugin.deactivate()
@@ -357,6 +369,10 @@ class PluginManager(metaclass=Singleton):
             self.gui_extension_points_handlers.setdefault(gui_extpoint_name,
                 []).append(gui_extpoint_handlers)
 
+    def _add_encryption_name_from_plugin(self, plugin):
+        if plugin.encryption_name:
+            self.encryption_plugins[plugin.encryption_name] = plugin
+
     @log_calls('PluginManager')
     def _handle_all_gui_extension_points_with_plugin(self, plugin):
         for gui_extpoint_name, gui_extpoint_handlers in \