From 360eae16461e0d961adf2bcafe1c394fbb9369e4 Mon Sep 17 00:00:00 2001
From: Tim Henkes <me@syndace.dev>
Date: Sat, 19 Oct 2024 18:13:01 +0200
Subject: [PATCH] Handle groupchat messages in decrypt_message

---
 CHANGELOG.md              |  3 +++
 slixmpp_omemo/xep_0384.py | 19 ++++++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 389f9fb..50b5b80 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased]
 
+### Fixed
+- Handle groupchat messages in `decrypt_message`
+
 ## [1.2.0] - 15th of October, 2024
 
 ### Changed
diff --git a/slixmpp_omemo/xep_0384.py b/slixmpp_omemo/xep_0384.py
index 46c3c35..5f82f01 100644
--- a/slixmpp_omemo/xep_0384.py
+++ b/slixmpp_omemo/xep_0384.py
@@ -15,6 +15,7 @@
     DeviceListDownloadFailed,
     DeviceListUploadFailed,
     MessageSendingFailed,
+    SenderNotFound,
     UnknownNamespace
 )
 from omemo.storage import Storage
@@ -32,6 +33,7 @@
 from slixmpp.jid import JID
 from slixmpp.plugins.base import BasePlugin
 from slixmpp.plugins.xep_0004 import Form  # type: ignore[attr-defined]
+from slixmpp.plugins.xep_0045 import XEP_0045  # type: ignore[attr-defined]
 from slixmpp.plugins.xep_0060 import XEP_0060  # type: ignore[attr-defined]
 from slixmpp.plugins.xep_0163 import XEP_0163
 from slixmpp.roster import RosterNode  # type: ignore[attr-defined]
@@ -1032,6 +1034,7 @@ async def decrypt_message(self, stanza: Message) -> Tuple[Message, DeviceInforma
 
         Raises:
             ValueError: in case there is malformed data not caught be the XML schema validation.
+            ValueError: in case a groupchat message is passed but XEP-0045 is not loaded.
             XMLSchemaValidationError: in case the element does not conform to the XML schema given in the
                 specification.
             SenderNotFound: in case the public information about the sending device could not be found or is
@@ -1041,7 +1044,21 @@ async def decrypt_message(self, stanza: Message) -> Tuple[Message, DeviceInforma
 
         xmpp: BaseXMPP = self.xmpp
 
-        sender_bare_jid = stanza.get_from().bare
+        from_jid: JID = stanza.get_from()
+        sender_bare_jid: str
+
+        if stanza.get_type() == "groupchat":
+            xep_0045: Optional[XEP_0045] = xmpp["xep_0045"]
+            if not xep_0045:
+                raise ValueError("Attempt to decrypt groupchat message but XEP-0045 is not loaded")
+
+            real_jid = xep_0045.get_jid_property(JID(from_jid.bare), from_jid.resource, "jid")
+            if real_jid is None:
+                raise SenderNotFound(f"Couldn't find real JID of sender from groupchat JID {from_jid}")
+
+            sender_bare_jid = JID(real_jid).bare
+        else:
+            sender_bare_jid = from_jid.bare
 
         session_manager = await self.get_session_manager()