fix: Somewhat fix OMEMO

packages/moxxmpp/lib/src/connection.dart

@@ -94,7 +94,7 @@ class XmppConnection {
     _awaitingResponseLock = Lock(),
     _xmppManagers = {},
     _incomingStanzaHandlers = List.empty(growable: true),
-    _incomingEncryptionStanzaHandlers = List.empty(growable: true),
+    _incomingPreStanzaHandlers = List.empty(growable: true),
     _outgoingPreStanzaHandlers = List.empty(growable: true),
     _outgoingPostStanzaHandlers = List.empty(growable: true),
     _reconnectionPolicy = reconnectionPolicy,
@@ -134,7 +134,7 @@ class XmppConnection {
   /// Helpers
   ///
   final List<StanzaHandler> _incomingStanzaHandlers;
-  final List<StanzaHandler> _incomingEncryptionStanzaHandlers;
+  final List<StanzaHandler> _incomingPreStanzaHandlers;
   final List<StanzaHandler> _outgoingPreStanzaHandlers;
   final List<StanzaHandler> _outgoingPostStanzaHandlers;
   final StreamController<XmppEvent> _eventStreamController;
@@ -225,13 +225,13 @@ class XmppConnection {
     }
 
     _incomingStanzaHandlers.addAll(manager.getIncomingStanzaHandlers());
-    _incomingEncryptionStanzaHandlers.addAll(manager.getIncomingEncryptionStanzaHandlers());
+    _incomingPreStanzaHandlers.addAll(manager.getIncomingPreStanzaHandlers());
     _outgoingPreStanzaHandlers.addAll(manager.getOutgoingPreStanzaHandlers());
     _outgoingPostStanzaHandlers.addAll(manager.getOutgoingPostStanzaHandlers());
     
     if (sortHandlers) {
       _incomingStanzaHandlers.sort(stanzaHandlerSortComparator);
-      _incomingEncryptionStanzaHandlers.sort(stanzaHandlerSortComparator);
+      _incomingPreStanzaHandlers.sort(stanzaHandlerSortComparator);
       _outgoingPreStanzaHandlers.sort(stanzaHandlerSortComparator);
       _outgoingPostStanzaHandlers.sort(stanzaHandlerSortComparator);
     }
@@ -634,12 +634,12 @@ class XmppConnection {
     return state;
   }
 
-  Future<StanzaHandlerData> _runIncomingStanzaHandlers(Stanza stanza) async {
+  Future<StanzaHandlerData> _runIncomingStanzaHandlers(Stanza stanza, { StanzaHandlerData? initial }) async {
-    return _runStanzaHandlers(_incomingStanzaHandlers, stanza);
+    return _runStanzaHandlers(_incomingStanzaHandlers, stanza, initial: initial);
   }
 
-  Future<StanzaHandlerData> _runIncomingEncryptionStanzaHandlers(Stanza stanza) async {
+  Future<StanzaHandlerData> _runIncomingPreStanzaHandlers(Stanza stanza) async {
-    return _runStanzaHandlers(_incomingEncryptionStanzaHandlers, stanza);
+    return _runStanzaHandlers(_incomingPreStanzaHandlers, stanza);
   }
 
   Future<StanzaHandlerData> _runOutgoingPreStanzaHandlers(Stanza stanza, { StanzaHandlerData? initial }) async {
@@ -681,18 +681,18 @@ class XmppConnection {
 
     // Run the incoming stanza handlers and bounce with an error if no manager handled
     // it.
-    final incomingEncryptionHandlers = await _runIncomingEncryptionStanzaHandlers(stanza);
+    final incomingPreHandlers = await _runIncomingPreStanzaHandlers(stanza);
-    final prefix = incomingEncryptionHandlers.encrypted ?
+    final prefix = incomingPreHandlers.encrypted && incomingPreHandlers.other['encryption_error'] == null ?
       '(Encrypted) ' :
       '';
-    _log.finest('<== $prefix${incomingEncryptionHandlers.stanza.toXml()}');
+    _log.finest('<== $prefix${incomingPreHandlers.stanza.toXml()}');
 
     // See if we are waiting for this stanza
-    final id = incomingEncryptionHandlers.stanza.attributes['id'] as String?;
+    final id = incomingPreHandlers.stanza.attributes['id'] as String?;
     var awaited = false;
     await _awaitingResponseLock.synchronized(() async {
       if (id != null && _awaitingResponse.containsKey(id)) {
-        _awaitingResponse[id]!.complete(incomingEncryptionHandlers.stanza);
+        _awaitingResponse[id]!.complete(incomingPreHandlers.stanza);
         _awaitingResponse.remove(id);
         awaited = true;
       }
@@ -703,9 +703,18 @@ class XmppConnection {
     }
 
     // Only bounce if the stanza has neither been awaited, nor handled.
-    final incomingHandlers = await _runIncomingStanzaHandlers(incomingEncryptionHandlers.stanza);
+    final incomingHandlers = await _runIncomingStanzaHandlers(
+      incomingPreHandlers.stanza,
+      initial: StanzaHandlerData(
+        false,
+        incomingPreHandlers.cancel,
+        incomingPreHandlers.cancelReason,
+        incomingPreHandlers.stanza,
+        other: incomingPreHandlers.other,
+      ),
+    );
     if (!incomingHandlers.done) {
-      handleUnhandledStanza(this, stanza);
+      handleUnhandledStanza(this, incomingPreHandlers.stanza);
     }
   }
 

packages/moxxmpp/lib/src/managers/base.dart

@@ -32,9 +32,10 @@ abstract class XmppManagerBase {
   /// receive.
   List<StanzaHandler> getIncomingStanzaHandlers() => [];
 
-  /// Return the StanzaHandlers associated with this manager that deal with stanzas we
+  /// Return the StanzaHandlers associated with this manager that deal with stanza handlers
-  /// may decrypt.
+  /// that have to run before the main ones run. This is useful, for example, for OMEMO
-  List<StanzaHandler> getIncomingEncryptionStanzaHandlers() => [];
+  /// as we have to decrypt the stanza before we do anything else.
+  List<StanzaHandler> getIncomingPreStanzaHandlers() => [];
   
   /// Return the NonzaHandlers associated with this manager.
   List<NonzaHandler> getNonzaHandlers() => [];

packages/moxxmpp/lib/src/xeps/xep_0280.dart

@@ -25,13 +25,12 @@ class CarbonsManager extends XmppManagerBase {
   String getName() => 'CarbonsManager';
 
   @override
-  List<StanzaHandler> getIncomingStanzaHandlers() => [
+  List<StanzaHandler> getIncomingPreStanzaHandlers() => [
     StanzaHandler(
       stanzaTag: 'message',
       tagName: 'received',
       tagXmlns: carbonsXmlns,
       callback: _onMessageReceived,
-      // Before all managers the message manager depends on
       priority: -98,
     ),
     StanzaHandler(
@@ -39,7 +38,6 @@ class CarbonsManager extends XmppManagerBase {
       tagName: 'sent',
       tagXmlns: carbonsXmlns,
       callback: _onMessageSent,
-      // Before all managers the message manager depends on
       priority: -98,
     )
   ];

packages/moxxmpp/lib/src/xeps/xep_0384/errors.dart

@@ -7,3 +7,5 @@ class InvalidAffixElementsException with Exception {}
 class OmemoNotSupportedForContactException extends OmemoError {}
 
 class EncryptionFailedException with Exception {}
+
+class InvalidEnvelopePayloadException with Exception {}

packages/moxxmpp/lib/src/xeps/xep_0384/xep_0384.dart

@@ -24,6 +24,7 @@ import 'package:moxxmpp/src/xeps/xep_0384/errors.dart';
 import 'package:moxxmpp/src/xeps/xep_0384/helpers.dart';
 import 'package:moxxmpp/src/xeps/xep_0384/types.dart';
 import 'package:omemo_dart/omemo_dart.dart';
+import 'package:xml/xml.dart';
 
 const _doNotEncryptList = [
   // XEP-0033
@@ -53,27 +54,24 @@ abstract class BaseOmemoManager extends XmppManagerBase {
   Future<bool> isSupported() async => true;
 
   @override
-  List<StanzaHandler> getIncomingEncryptionStanzaHandlers() => [
+  List<StanzaHandler> getIncomingPreStanzaHandlers() => [
     StanzaHandler(
       stanzaTag: 'iq',
       tagXmlns: omemoXmlns,
       tagName: 'encrypted',
       callback: _onIncomingStanza,
-      priority: 9999,
     ),
     StanzaHandler(
       stanzaTag: 'presence',
       tagXmlns: omemoXmlns,
       tagName: 'encrypted',
       callback: _onIncomingStanza,
-      priority: 9999,
     ),
     StanzaHandler(
       stanzaTag: 'message',
       tagXmlns: omemoXmlns,
       tagName: 'encrypted',
       callback: _onIncomingStanza,
-      priority: -98,
     ),
   ];
 
@@ -432,16 +430,29 @@ abstract class BaseOmemoManager extends XmppManagerBase {
       ),
     );
 
-    final children = stanza.children.where(
-      (child) => child.tag != 'encrypted' || child.attributes['xmlns'] != omemoXmlns,
-    ).toList();
     final other = Map<String, dynamic>.from(state.other);
+    var children = stanza.children;
     if (result.error != null) {
       other['encryption_error'] = result.error;
+    } else {
+      children = stanza.children.where(
+        (child) => child.tag != 'encrypted' || child.attributes['xmlns'] != omemoXmlns,
+      ).toList();
     }
 
     if (result.payload != null) {
-      final envelope = XMLNode.fromString(result.payload!);
+      XMLNode envelope;
+      try {
+        envelope = XMLNode.fromString(result.payload!);
+      } on XmlParserException catch (_) {
+        logger.warning('Failed to parse envelope payload: ${result.payload!}');
+        other['encryption_error'] = InvalidEnvelopePayloadException();
+        return state.copyWith(
+          encrypted: true,
+          other: other,
+        );
+      }
+
       children.addAll(
         envelope.firstTag('content')!.children,
       );