[esessions] Initial

esessions/__init__.py

+from .esessions import ESessionsPlugin

esessions/esessions.py

+# -*- coding: utf-8 -*-
+
+'''
+Copyright 2017 Philipp Hörist <philipp@hoerist.com>
+
+This file is part of Gajim.
+
+Gajim is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published
+by the Free Software Foundation; version 3 only.
+
+Gajim is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Gajim. If not, see <http://www.gnu.org/licenses/>.
+'''
+
+import os
+import logging
+import time
+import threading
+import queue
+
+import nbxmpp
+
+import dialogs
+import gtkgui_helpers
+
+from common import gajim
+from common.connection_handlers_events import (
+    FailedDecryptEvent, MamMessageReceivedEvent)
+from plugins import GajimPlugin
+
+log = logging.getLogger('gajim.plugin_system.esessions')
+
+ERROR_MSG = ''
+if not gajim.HAVE_PYCRYPTO:
+    ERROR_MSG = 'Please install pycrypto'
+
+
+class ESessionsPlugin(GajimPlugin):
+
+    def init(self):
+        """ Init """
+        if ERROR_MSG:
+            # self.activatable = False
+            self.available_text = ERROR_MSG
+        self.config_dialog = None
+        self.encryption_name = 'ESessions'
+        self.config_dialog = None
+        self.gui_extension_points = {
+            'decrypt': (self._message_received, None),
+            'encrypt' + self.encryption_name: (self._encrypt_message, None),
+            'send_message' + self.encryption_name: (
+                self._before_sendmessage, None),
+            'encryption_dialog' + self.encryption_name: (
+                self.encryption_dialog, None),
+            'encryption_state' + self.encryption_name: (
+                self.encryption_state, None),
+            'typing' + self.encryption_name: (
+                self.typing, None)}
+
+    def activate(self):
+        pass
+
+    def deactivate(self):
+        pass
+
+    @staticmethod
+    def activate_encryption(chat_control):
+        contact = chat_control.contact
+        useable = contact.supports(nbxmpp.NS_ESESSION)
+        if useable:
+            chat_control.activate_esessions()
+        return bool(useable)
+
+    @staticmethod
+    def encryption_dialog(chat_control):
+        ESessionInfoWindow(chat_control.session,
+                           chat_control.parent_win.window)
+
+    @staticmethod
+    def encryption_state(chat_control, state):
+        session = chat_control.session
+        if not session:
+            return
+        authenticated = chat_control.session.verified_identity
+        state['authenticated'] = session and authenticated
+        state['visible'] = True
+
+    @staticmethod
+    def typing(chat_control):
+        contact = chat_control.contact
+        enabled = chat_control.session.enable_encryption
+        if contact.supports(nbxmpp.NS_ESESSION):
+            if not (chat_control.session and enabled):
+                if not chat_control.no_autonegotiation:
+                    chat_control.activate_esessions()
+
+    @staticmethod
+    def _before_sendmessage(chat_control):
+        enabled = chat_control.session.enable_encryption
+        if not (chat_control.session and enabled):
+            dialogs.ErrorDialog(
+                _('No Session'),
+                _('You have no valid Session with that contact.'))
+            chat_control.sendmessage = False
+
+    def _message_received(self, conn, obj, callback):
+        if obj.encrypted:
+            # Another Plugin already decrypted the message
+            return
+        if isinstance(obj, MamMessageReceivedEvent):
+            # Esessions doesnt support MAM Messages
+            return
+        if obj.forwarded:
+            # Esessions cant decrypt Carbon Copys
+            return
+        if obj.stanza.getTag('feature', namespace=nbxmpp.NS_FEATURE):
+            if gajim.HAVE_PYCRYPTO:
+                feature = obj.stanza.getTag(name='feature',
+                                            namespace=nbxmpp.NS_FEATURE)
+                form = nbxmpp.DataForm(node=feature.getTag('x'))
+                if not form:
+                    return
+
+                if not form.getField('FORM_TYPE'):
+                    return
+
+                if form['FORM_TYPE'] == 'urn:xmpp:ssn':
+                    obj.session.handle_negotiation(form)
+                else:
+                    reply = obj.stanza.buildReply()
+                    reply.setType('error')
+                    reply.addChild(feature)
+                    err = nbxmpp.ErrorNode('service-unavailable', typ='cancel')
+                    reply.addChild(node=err)
+                    conn.connection.send(reply)
+            return
+
+        if obj.stanza.getTag('init', namespace=nbxmpp.NS_ESESSION_INIT):
+            init = obj.stanza.getTag(name='init',
+                                     namespace=nbxmpp.NS_ESESSION_INIT)
+            form = nbxmpp.DataForm(node=init.getTag('x'))
+
+            obj.session.handle_negotiation(form)
+            return
+
+        encrypted = obj.stanza.getTag(
+            'c', namespace=nbxmpp.NS_STANZA_CRYPTO)
+        if encrypted:
+            try:
+                obj.stanza = obj.session.decrypt_stanza(obj.stanza)
+                obj.msgtxt = obj.stanza.getBody()
+                obj.encrypted = 'ESessions'
+                callback(obj)
+            except Exception:
+                gajim.nec.push_incoming_event(
+                    FailedDecryptEvent(None, conn=conn, msg_obj=obj))
+                return
+
+    def _encrypt_message(self, conn, obj, callback):
+        if obj.session.enable_encryption:
+            obj.msg_iq = obj.session.encrypt_stanza(obj.msg_iq)
+            obj.msg_iq.addChild(name='private', namespace=nbxmpp.NS_CARBONS)
+            obj.msg_iq.addChild(name='no-permanent-store',
+                                namespace=nbxmpp.NS_MSG_HINTS)
+            obj.msg_iq.addChild(name='no-copy',
+                                namespace=nbxmpp.NS_MSG_HINTS)
+            eme_node = nbxmpp.Node('encryption',
+                                   attrs={'xmlns': nbxmpp.NS_EME,
+                                          'name': 'ESessions',
+                                          'namespace': nbxmpp.NS_STANZA_CRYPTO})
+            obj.msg_iq.addChild(node=eme_node)
+        callback(obj)
+
+
+class ESessionInfoWindow:
+    """
+    Class for displaying information about a XEP-0116 encrypted session
+    """
+    def __init__(self, session, transient_for=None):
+        self.session = session
+
+        self.xml = gtkgui_helpers.get_gtk_builder('esession_info_window.ui')
+        self.xml.connect_signals(self)
+
+        self.security_image = self.xml.get_object('security_image')
+        self.verify_now_button = self.xml.get_object('verify_now_button')
+        self.button_label = self.xml.get_object('verification_status_label')
+        self.window = self.xml.get_object('esession_info_window')
+        self.update_info()
+        self.window.set_transient_for(transient_for)
+
+        self.window.show_all()
+
+    def get_sas(self):
+        sas = ''
+        if hasattr(self.session, 'sas'):
+            sas = self.session.sas
+        return sas
+
+    def update_info(self):
+
+        labeltext = _(
+            '''Your chat session with <b>%(jid)s</b> is encrypted.\n\n
+            This session's Short Authentication String is <b>%(sas)s</b>.
+            ''') % {'jid': self.session.jid, 'sas': self.get_sas()}
+
+        if self.session.verified_identity:
+            labeltext += '\n\n' + _(
+                '''You have already verified this contact's identity.''')
+            security_image = 'security-high'
+            if self.session.control:
+                self.session.control.set_lock_image()
+
+            verification_status = _('''Contact's identity verified''')
+            self.window.set_title(verification_status)
+            self.xml.get_object('verification_status_label').set_markup(
+                '<b><span size="x-large">%s</span></b>' % verification_status)
+
+            self.xml.get_object('dialog-action_area1').set_no_show_all(True)
+            self.button_label.set_text(_('Verify again…'))
+        else:
+            if self.session.control:
+                self.session.control.set_lock_image()
+            labeltext += '\n\n' + _(
+                '''To be certain that <b>only</b> the expected person can read
+                your messages or send you messages, you need to verify their
+                identity by clicking the button below.''')
+            security_image = 'security-low'
+
+            verification_status = _('''Contact's identity NOT verified''')
+            self.window.set_title(verification_status)
+            self.xml.get_object('verification_status_label').set_markup(
+                '<b><span size="x-large">%s</span></b>' % verification_status)
+
+            self.button_label.set_text(_('Verify…'))
+
+        path = gtkgui_helpers.get_icon_path(security_image, 32)
+        self.security_image.set_from_file(path)
+
+        self.xml.get_object('info_display').set_markup(labeltext)
+
+    def on_close_button_clicked(self, widget):
+        self.window.destroy()
+
+    def on_verify_now_button_clicked(self, widget):
+        pritext = _('''Have you verified the contact's identity?''')
+        sectext = _('''
+            To prevent talking to an unknown person, you should
+            speak to <b>%(jid)s</b> directly (in person or on the phone)
+            and verify that they see the same Short Authentication String (SAS)
+            as you.\n\n
+            This session's Short Authentication String is <b>%(sas)s</b>.
+            ''') % {'jid': self.session.jid, 'sas': self.get_sas()}
+        sectext += '\n\n' + _(
+            'Did you talk to the remote contact and verify the SAS?')
+
+        def on_yes(checked):
+            self.session._verified_srs_cb()
+            self.session.verified_identity = True
+            self.update_info()
+
+        def on_no():
+            self.session._unverified_srs_cb()
+            self.session.verified_identity = False
+            self.update_info()
+
+        dialogs.YesNoDialog(pritext, sectext,
+                            on_response_yes=on_yes,
+                            on_response_no=on_no,
+                            transient_for=self.window)

esessions/manifest.ini

+[info]
+name: ESessions
+short_name: esessions
+version: 1.0.0
+description: Encryption as per XEP-0200
+authors: Philipp Hörist <philipp@hoerist.com>
+homepage: https://dev.gajim.org/gajim/gajim-plugins/wikis/esessions
+min_gajim_version: 0.16.10