First shot of an E2EE plugin interface

Features:
- Decryption by default once the plugin is loaded if messages contains
the right EME magic
- Encryption of messages only if encryption is enabled for the current
tab

Missing pieces:
- No special treatment done on the order of the treatment for messages
yet
- No special handling of non-Partial(/Full) Stanza Encryption yet (i.e.,
removing stuff other than <body/>)

Signed-off-by: Maxime “pep” Buquet <pep@bouah.net>

1 files changed, 50 insertions, 0 deletions

diff --git a/plugins/b64.py b/plugins/b64.py
new file mode 100644
index 00000000..57b2664f
--- /dev/null
+++ b/plugins/b64.py
@@ -0,0 +1,50 @@
+#! /usr/bin/env python3
+# -*- coding: utf-8 -*-
+# vim:fenc=utf-8
+#
+# Copyright © 2019 Maxime “pep” Buquet <pep@bouah.net>
+#
+# Distributed under terms of the zlib license.
+
+"""
+Usage
+-----
+
+Base64 encryption plugin.
+
+This plugin also respects security guidelines listed in XEP-0419.
+
+.. glossary::
+    /b64
+        **Usage:** ``/b64``
+
+        This command enables encryption of outgoing messages for the current
+        tab.
+"""
+
+from base64 import b64decode, b64encode
+from poezio.plugin_e2ee import E2EEPlugin
+from slixmpp import Message
+
+
+class Plugin(E2EEPlugin):
+    """Base64 Plugin"""
+
+    encryption_name = 'base64'
+    encryption_short_name = 'b64'
+    eme_ns = 'urn:xmpps:base64:0'
+
+    def decrypt(self, message: Message, _tab) -> None:
+        """
+            Decrypt base64
+        """
+        body = message['body']
+        message['body'] = b64decode(body.encode()).decode()
+
+    def encrypt(self, message: Message, _tab) -> None:
+        """
+            Encrypt to base64
+        """
+        # TODO: Stop using <body/> for this. Put the encoded payload in another element.
+        body = message['body']
+        message['body'] = b64encode(body.encode()).decode()