[omemo] Add PEP devicelist module

omemo/modules/util.py

@@ -0,0 +1,46 @@
+# Copyright (C) 2018 Philipp Hörist <philipp AT hoerist.com>
+#
+# This file is part of OMEMO.
+#
+# OMEMO 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.
+#
+# OMEMO 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 OMEMO. If not, see <http://www.gnu.org/licenses/>.
+
+# XEP-0384: OMEMO Encryption
+
+import logging
+
+import nbxmpp
+
+from gajim.common.exceptions import StanzaMalformed
+
+
+log = logging.getLogger('gajim.plugin_system.omemo')
+
+NS_OMEMO = 'eu.siacs.conversations.axolotl'
+NS_DEVICE_LIST = NS_OMEMO + '.devicelist'
+
+
+def unpack_devicelist(item):
+    list_ = item.getTag('list', namespace=NS_OMEMO)
+    if list_ is None:
+        raise StanzaMalformed('No list node')
+
+    device_list = list_.getTags('device')
+
+    devices = []
+    for device in device_list:
+        id_ = device.getAttr('id')
+        if id_ is None:
+            raise StanzaMalformed('No id for device found')
+
+        devices.append(int(id_))
+    return devices