message integrity

lib/chat/cubits/reconciliation/author_input_queue.dart

@@ -1,145 +1,191 @@
 import 'dart:async';
-import 'dart:collection';
-import 'dart:math';
-
-import 'package:fast_immutable_collections/fast_immutable_collections.dart';
 import 'package:veilid_support/veilid_support.dart';
 
 import '../../../proto/proto.dart' as proto;
 
 import 'author_input_source.dart';
+import 'message_integrity.dart';
 import 'output_position.dart';
 
 class AuthorInputQueue {
-  AuthorInputQueue({
-    required this.author,
-    required this.inputSource,
-    required this.lastOutputPosition,
-    required this.onError,
-  }):
-    assert(inputSource.messages.count>0, 'no input source window length'),
-    assert(inputSource.messages.elements.isNotEmpty, 'no input source elements'),
-    assert(inputSource.messages.tail >= inputSource.messages.elements.length, 'tail is before initial messages end'),
-    assert(inputSource.messages.tail > 0, 'tail is not greater than zero'),
-    currentPosition = inputSource.messages.tail,
-    currentWindow = inputSource.messages.elements,
-    windowLength = inputSource.messages.count,
-    windowFirst = inputSource.messages.tail - inputSource.messages.elements.length,
-    windowLast = inputSource.messages.tail - 1;
+  AuthorInputQueue._({
+    required TypedKey author,
+    required AuthorInputSource inputSource,
+    required OutputPosition? outputPosition,
+    required void Function(Object, StackTrace?) onError,
+    required MessageIntegrity messageIntegrity,
+  })  : _author = author,
+        _onError = onError,
+        _inputSource = inputSource,
+        _outputPosition = outputPosition,
+        _lastMessage = outputPosition?.message,
+        _messageIntegrity = messageIntegrity,
+        _currentPosition = inputSource.currentWindow.last;
 
-  ////////////////////////////////////////////////////////////////////////////
-
-  bool get isEmpty => toReconcile.isEmpty;
-
-  proto.Message? get current => toReconcile.firstOrNull;
-
-  bool consume() {
-    toReconcile.removeFirst();
-    return toReconcile.isNotEmpty;
+  static Future<AuthorInputQueue?> create({
+    required TypedKey author,
+    required AuthorInputSource inputSource,
+    required OutputPosition? outputPosition,
+    required void Function(Object, StackTrace?) onError,
+  }) async {
+    final queue = AuthorInputQueue._(
+        author: author,
+        inputSource: inputSource,
+        outputPosition: outputPosition,
+        onError: onError,
+        messageIntegrity: await MessageIntegrity.create(author: author));
+    if (!await queue._findStartOfWork()) {
+      return null;
+    }
+    return queue;
   }
 
-  Future<bool> prepareInputQueue() async {
-    // Go through batches of the input dhtlog starting with
-    // the current cubit state which is at the tail of the log
-    // Find the last reconciled message for this author
+  ////////////////////////////////////////////////////////////////////////////
+  // Public interface
 
-    outer:
+  // Check if there are no messages in this queue to reconcile
+  bool get isEmpty => _currentMessage == null;
+
+  // Get the current message that needs reconciliation
+  proto.Message? get current => _currentMessage;
+
+  // Get the earliest output position to start inserting
+  OutputPosition? get outputPosition => _outputPosition;
+
+  // Get the author of this queue
+  TypedKey get author => _author;
+
+  // Remove a reconciled message and move to the next message
+  // Returns true if there is more work to do
+  Future<bool> consume() async {
     while (true) {
-      for (var rn = currentWindow.length;
-          rn >= 0 && currentPosition >= 0;
-          rn--, currentPosition--) {
-        final elem = currentWindow[rn];
+      _lastMessage = _currentMessage;
 
-        // If we've found an input element that is older than our last
-        // reconciled message for this author, then we stop
-        if (lastOutputPosition != null) {
-          if (elem.value.timestamp < lastOutputPosition!.message.timestamp) {
-            break outer;
-          }
-        }
+      _currentPosition++;
 
-        // Drop the 'offline' elements because we don't reconcile
-        // anything until it has been confirmed to be committed to the DHT
-        if (elem.isOffline) {
+      // Get more window if we need to
+      if (!await _updateWindow()) {
+        // Window is not available so this queue can't work right now
+        return false;
+      }
+      final nextMessage = _inputSource.currentWindow
+          .elements[_currentPosition - _inputSource.currentWindow.first];
+
+      // Drop the 'offline' elements because we don't reconcile
+      // anything until it has been confirmed to be committed to the DHT
+      if (nextMessage.isOffline) {
+        continue;
+      }
+
+      if (_lastMessage != null) {
+        // Ensure the timestamp is not moving backward
+        if (nextMessage.value.timestamp < _lastMessage!.timestamp) {
           continue;
         }
-
-        // Add to head of reconciliation queue
-        toReconcile.addFirst(elem.value);
-        if (toReconcile.length > _maxQueueChunk) {
-          toReconcile.removeLast();
-        }
-      }
-      if (currentPosition < 0) {
-        break;
       }
 
-    xxx update window here and make this and other methods work
+      // Verify the id chain for the message
+      final matchId = await _messageIntegrity.generateMessageId(_lastMessage);
+      if (matchId.compare(nextMessage.value.idBytes) != 0) {
+        continue;
+      }
+
+      // Verify the signature for the message
+      if (!await _messageIntegrity.verifyMessage(nextMessage.value)) {
+        continue;
+      }
+
+      _currentMessage = nextMessage.value;
+      break;
     }
     return true;
   }
 
+  ////////////////////////////////////////////////////////////////////////////
+  // Internal implementation
+
+  // Walk backward from the tail of the input queue to find the first
+  // message newer than our last reconcicled message from this author
+  // Returns false if no work is needed
+  Future<bool> _findStartOfWork() async {
+    // Iterate windows over the inputSource
+    outer:
+    while (true) {
+      // Iterate through current window backward
+      for (var i = _inputSource.currentWindow.elements.length;
+          i >= 0 && _currentPosition >= 0;
+          i--, _currentPosition--) {
+        final elem = _inputSource.currentWindow.elements[i];
+
+        // If we've found an input element that is older than our last
+        // reconciled message for this author, then we stop
+        if (_lastMessage != null) {
+          if (elem.value.timestamp < _lastMessage!.timestamp) {
+            break outer;
+          }
+        }
+      }
+      // If we're at the beginning of the inputSource then we stop
+      if (_currentPosition < 0) {
+        break;
+      }
+
+      // Get more window if we need to
+      if (!await _updateWindow()) {
+        // Window is not available or things are empty so this
+        // queue can't work right now
+        return false;
+      }
+    }
+
+    // The current position should be equal to the first message to process
+    // and the current window to process should not be empty
+    return _inputSource.currentWindow.elements.isNotEmpty;
+  }
+
   // Slide the window toward the current position and load the batch around it
-  Future<bool> updateWindow() async {
-
-      // Check if we are still in the window
-      if (currentPosition>=windowFirst && currentPosition <= windowLast) {
-        return true;
-      }
-
-      // Get the length of the cubit
-      final inputLength = await inputSource.cubit.operate((r) async => r.length);
-
-      // If not, slide the window
-      if (currentPosition<windowFirst) {
-        // Slide it backward, current position is now windowLast
-        windowFirst = max((currentPosition - windowLength) + 1, 0);
-        windowLast = currentPosition;
-      } else {
-        // Slide it forward, current position is now windowFirst
-        windowFirst = currentPosition;
-        windowLast = min((currentPosition + windowLength) - 1, inputLength - 1);
-      }
-
-      // Get another input batch futher back
-      final nextWindow =
-          await inputSource.cubit.loadElements(windowLast + 1, (windowLast + 1) - windowFirst);
-      final asErr = nextWindow.asError;
-      if (asErr != null) {
-        onError(asErr.error, asErr.stackTrace);
-        return false;
-      }
-      final asLoading = nextWindow.asLoading;
-      if (asLoading != null) {
-        // xxx: no need to block the cubit here for this
-        // xxx: might want to switch to a 'busy' state though
-        // xxx: to let the messages view show a spinner at the bottom
-        // xxx: while we reconcile...
-        // emit(const AsyncValue.loading());
-        return false;
-      }
-      currentWindow = nextWindow.asData!.value;
+  Future<bool> _updateWindow() async {
+    // Check if we are still in the window
+    if (_currentPosition >= _inputSource.currentWindow.first &&
+        _currentPosition <= _inputSource.currentWindow.last) {
       return true;
+    }
+
+    // Get another input batch futher back
+    final avOk =
+        await _inputSource.updateWindow(_currentPosition, _maxWindowLength);
+
+    final asErr = avOk.asError;
+    if (asErr != null) {
+      _onError(asErr.error, asErr.stackTrace);
+      return false;
+    }
+    final asLoading = avOk.asLoading;
+    if (asLoading != null) {
+      // xxx: no need to block the cubit here for this
+      // xxx: might want to switch to a 'busy' state though
+      // xxx: to let the messages view show a spinner at the bottom
+      // xxx: while we reconcile...
+      // emit(const AsyncValue.loading());
+      return false;
+    }
+    return avOk.asData!.value;
   }
 
   ////////////////////////////////////////////////////////////////////////////
 
-  final TypedKey author;
-  final ListQueue<proto.Message> toReconcile = ListQueue<proto.Message>();
-  final AuthorInputSource inputSource;
-  final OutputPosition? lastOutputPosition;
-  final void Function(Object, StackTrace?) onError;
+  final TypedKey _author;
+  final AuthorInputSource _inputSource;
+  final OutputPosition? _outputPosition;
+  final void Function(Object, StackTrace?) _onError;
+  final MessageIntegrity _messageIntegrity;
 
+  // The last message we've consumed
+  proto.Message? _lastMessage;
   // The current position in the input log that we are looking at
-  int currentPosition;
-  // The current input window elements
-  IList<DHTLogElementState<proto.Message>> currentWindow;
-  // The first position of the sliding input window
-  int windowFirst;
-  // The last position of the sliding input window
-  int windowLast;
+  int _currentPosition;
+  // The current message we're looking at
+  proto.Message? _currentMessage;
   // Desired maximum window length
-  int windowLength;
-
-  static const int _maxQueueChunk = 256;
+  static const int _maxWindowLength = 256;
 }

lib/chat/cubits/reconciliation/author_input_source.dart

@@ -1,10 +1,76 @@
+import 'dart:math';
+
+import 'package:async_tools/async_tools.dart';
+import 'package:fast_immutable_collections/fast_immutable_collections.dart';
+import 'package:meta/meta.dart';
 import 'package:veilid_support/veilid_support.dart';
 
 import '../../../proto/proto.dart' as proto;
 
-class AuthorInputSource {
-  AuthorInputSource({required this.messages, required this.cubit});
-
-  final DHTLogStateData<proto.Message> messages;
-  final DHTLogCubit<proto.Message> cubit;
+@immutable
+class InputWindow {
+  const InputWindow(
+      {required this.elements, required this.first, required this.last});
+  final IList<OnlineElementState<proto.Message>> elements;
+  final int first;
+  final int last;
+}
+
+class AuthorInputSource {
+  AuthorInputSource.fromCubit(
+      {required DHTLogStateData<proto.Message> cubitState,
+      required this.cubit}) {
+    _currentWindow = InputWindow(
+        elements: cubitState.elements,
+        first: cubitState.tail - cubitState.elements.length,
+        last: cubitState.tail - 1);
+  }
+
+  ////////////////////////////////////////////////////////////////////////////
+
+  InputWindow get currentWindow => _currentWindow;
+
+  Future<AsyncValue<bool>> updateWindow(
+          int currentPosition, int windowLength) async =>
+      cubit.operate((reader) async {
+        // See if we're beyond the input source
+        if (currentPosition < 0 || currentPosition >= reader.length) {
+          return const AsyncValue.data(false);
+        }
+
+        // Slide the window if we need to
+        var first = _currentWindow.first;
+        var last = _currentWindow.last;
+        if (currentPosition < first) {
+          // Slide it backward, current position is now last
+          first = max((currentPosition - windowLength) + 1, 0);
+          last = currentPosition;
+        } else if (currentPosition > last) {
+          // Slide it forward, current position is now first
+          first = currentPosition;
+          last = min((currentPosition + windowLength) - 1, reader.length - 1);
+        } else {
+          return const AsyncValue.data(true);
+        }
+
+        // Get another input batch futher back
+        final nextWindow = await cubit.loadElementsFromReader(
+            reader, last + 1, (last + 1) - first);
+        final asErr = nextWindow.asError;
+        if (asErr != null) {
+          return AsyncValue.error(asErr.error, asErr.stackTrace);
+        }
+        final asLoading = nextWindow.asLoading;
+        if (asLoading != null) {
+          return const AsyncValue.loading();
+        }
+        _currentWindow = InputWindow(
+            elements: nextWindow.asData!.value, first: first, last: last);
+        return const AsyncValue.data(true);
+      });
+
+  ////////////////////////////////////////////////////////////////////////////
+  final DHTLogCubit<proto.Message> cubit;
+
+  late InputWindow _currentWindow;
 }

lib/chat/cubits/reconciliation/message_integrity.dart

@@ -0,0 +1,74 @@
+import 'dart:convert';
+import 'dart:typed_data';
+
+import 'package:protobuf/protobuf.dart';
+import 'package:veilid_support/veilid_support.dart';
+import '../../../proto/proto.dart' as proto;
+
+class MessageIntegrity {
+  MessageIntegrity._({
+    required TypedKey author,
+    required VeilidCryptoSystem crypto,
+  })  : _author = author,
+        _crypto = crypto;
+  static Future<MessageIntegrity> create({required TypedKey author}) async {
+    final crypto = await Veilid.instance.getCryptoSystem(author.kind);
+    return MessageIntegrity._(author: author, crypto: crypto);
+  }
+
+  ////////////////////////////////////////////////////////////////////////////
+  // Public interface
+
+  Future<Uint8List> generateMessageId(proto.Message? previous) async {
+    if (previous == null) {
+      // If there's no last sent message,
+      // we start at a hash of the identity public key
+      return _generateInitialId();
+    } else {
+      // If there is a last message, we generate the hash
+      // of the last message's signature and use it as our next id
+      return _hashSignature(previous.signature);
+    }
+  }
+
+  Future<void> signMessage(
+    proto.Message message,
+    SecretKey authorSecret,
+  ) async {
+    // Ensure this message is not already signed
+    assert(!message.hasSignature(), 'should not sign message twice');
+    // Generate data to sign
+    final data = Uint8List.fromList(utf8.encode(message.writeToJson()));
+
+    // Sign with our identity
+    final signature = await _crypto.sign(_author.value, authorSecret, data);
+
+    // Add to the message
+    message.signature = signature.toProto();
+  }
+
+  Future<bool> verifyMessage(proto.Message message) async {
+    // Ensure the message is signed
+    assert(message.hasSignature(), 'should not verify unsigned message');
+    final signature = message.signature.toVeilid();
+
+    // Generate data to sign
+    final messageNoSig = message.deepCopy()..clearSignature();
+    final data = Uint8List.fromList(utf8.encode(messageNoSig.writeToJson()));
+
+    // Verify signature
+    return _crypto.verify(_author.value, data, signature);
+  }
+
+  ////////////////////////////////////////////////////////////////////////////
+  // Private implementation
+
+  Future<Uint8List> _generateInitialId() async =>
+      (await _crypto.generateHash(_author.decode())).decode();
+
+  Future<Uint8List> _hashSignature(proto.Signature signature) async =>
+      (await _crypto.generateHash(signature.toVeilid().decode())).decode();
+  ////////////////////////////////////////////////////////////////////////////
+  final TypedKey _author;
+  final VeilidCryptoSystem _crypto;
+}

lib/chat/cubits/reconciliation/message_reconciliation.dart

@@ -21,14 +21,14 @@ class MessageReconciliation {
 
   void reconcileMessages(
       TypedKey author,
-      DHTLogStateData<proto.Message> inputMessages,
+      DHTLogStateData<proto.Message> inputMessagesCubitState,
       DHTLogCubit<proto.Message> inputMessagesCubit) {
-    if (inputMessages.elements.isEmpty) {
+    if (inputMessagesCubitState.elements.isEmpty) {
       return;
     }
 
-    _inputSources[author] =
-        AuthorInputSource(messages: inputMessages, cubit: inputMessagesCubit);
+    _inputSources[author] = AuthorInputSource.fromCubit(
+        cubitState: inputMessagesCubitState, cubit: inputMessagesCubit);
 
     singleFuture(this, onError: _onError, () async {
       // Take entire list of input sources we have currently and process them
@@ -63,14 +63,15 @@ class MessageReconciliation {
       {required TypedKey author,
       required AuthorInputSource inputSource}) async {
     // Get the position of our most recent reconciled message from this author
-    final lastReconciledMessage =
-        await _findNewestReconciledMessage(author: author);
+    final outputPosition = await _findLastOutputPosition(author: author);
 
     // Find oldest message we have not yet reconciled
-    final inputQueue = await _buildAuthorInputQueue(
-        author: author,
-        inputSource: inputSource,
-        lastOutputPosition: lastReconciledMessage);
+    final inputQueue = await AuthorInputQueue.create(
+      author: author,
+      inputSource: inputSource,
+      outputPosition: outputPosition,
+      onError: _onError,
+    );
     return inputQueue;
   }
 
@@ -78,7 +79,7 @@ class MessageReconciliation {
   // reconciled message from this author
   // XXX: For a group chat, this should find when the author
   // was added to the membership so we don't just go back in time forever
-  Future<OutputPosition?> _findNewestReconciledMessage(
+  Future<OutputPosition?> _findLastOutputPosition(
           {required TypedKey author}) async =>
       _outputCubit.operate((arr) async {
         var pos = arr.length - 1;
@@ -95,26 +96,6 @@ class MessageReconciliation {
         return null;
       });
 
-  // Find oldest message we have not yet reconciled and build a queue forward
-  // from that position
-  Future<AuthorInputQueue?> _buildAuthorInputQueue(
-      {required TypedKey author,
-      required AuthorInputSource inputSource,
-      required OutputPosition? lastOutputPosition}) async {
-    // Make an author input queue
-    final authorInputQueue = AuthorInputQueue(
-        author: author,
-        inputSource: inputSource,
-        lastOutputPosition: lastOutputPosition,
-        onError: _onError);
-
-    if (!await authorInputQueue.prepareInputQueue()) {
-      return null;
-    }
-
-    return authorInputQueue;
-  }
-
   // Process a list of author input queues and insert their messages
   // into the output array, performing validation steps along the way
   Future<void> _reconcileInputQueues({
@@ -130,8 +111,8 @@ class MessageReconciliation {
     // Sort queues from earliest to latest and then by author
     // to ensure a deterministic insert order
     inputQueues.sort((a, b) {
-      final acmp = a.lastOutputPosition?.pos ?? -1;
-      final bcmp = b.lastOutputPosition?.pos ?? -1;
+      final acmp = a.outputPosition?.pos ?? -1;
+      final bcmp = b.outputPosition?.pos ?? -1;
       if (acmp == bcmp) {
         return a.author.toString().compareTo(b.author.toString());
       }
@@ -139,7 +120,7 @@ class MessageReconciliation {
     });
 
     // Start at the earliest position we know about in all the queues
-    final firstOutputPos = inputQueues.first.lastOutputPosition?.pos;
+    final firstOutputPos = inputQueues.first.outputPosition?.pos;
     // Get the timestamp for this output position
     var currentOutputMessage = firstOutputPos == null
         ? null
@@ -167,7 +148,7 @@ class MessageReconciliation {
             added = true;
 
             // Advance this queue
-            if (!inputQueue.consume()) {
+            if (!await inputQueue.consume()) {
               // Queue is empty now, run a queue purge
               someQueueEmpty = true;
             }

lib/chat/cubits/reconciliation/reconciliation.dart

@@ -1 +1,2 @@
+export 'message_integrity.dart';
 export 'message_reconciliation.dart';

lib/chat/cubits/single_contact_messages_cubit.dart

@@ -1,6 +1,4 @@
 import 'dart:async';
-import 'dart:convert';
-import 'dart:typed_data';
 
 import 'package:async_tools/async_tools.dart';
 import 'package:fast_immutable_collections/fast_immutable_collections.dart';
@@ -10,7 +8,7 @@ import 'package:veilid_support/veilid_support.dart';
 import '../../account_manager/account_manager.dart';
 import '../../proto/proto.dart' as proto;
 import '../models/models.dart';
-import 'message_reconciliation.dart';
+import 'reconciliation/reconciliation.dart';
 
 class RenderStateElement {
   RenderStateElement(
@@ -102,12 +100,11 @@ class SingleContactMessagesCubit extends Cubit<SingleContactMessagesState> {
 
   // Make crypto
   Future<void> _initCrypto() async {
-    _messagesCrypto = await _activeAccountInfo
+    _conversationCrypto = await _activeAccountInfo
         .makeConversationCrypto(_remoteIdentityPublicKey);
-    _localMessagesCryptoSystem =
-        await Veilid.instance.getCryptoSystem(_localMessagesRecordKey.kind);
-    _identityCryptoSystem =
-        await _activeAccountInfo.localAccount.identityMaster.identityCrypto;
+    _senderMessageIntegrity = await MessageIntegrity.create(
+        author: _activeAccountInfo.localAccount.identityMaster
+            .identityPublicTypedKey());
   }
 
   // Open local messages key
@@ -119,7 +116,7 @@ class SingleContactMessagesCubit extends Cubit<SingleContactMessagesState> {
             debugName: 'SingleContactMessagesCubit::_initSentMessagesCubit::'
                 'SentMessages',
             parent: _localConversationRecordKey,
-            crypto: _messagesCrypto),
+            crypto: _conversationCrypto),
         decodeElement: proto.Message.fromBuffer);
     _sentSubscription =
         _sentMessagesCubit!.stream.listen(_updateSentMessagesState);
@@ -133,7 +130,7 @@ class SingleContactMessagesCubit extends Cubit<SingleContactMessagesState> {
             debugName: 'SingleContactMessagesCubit::_initRcvdMessagesCubit::'
                 'RcvdMessages',
             parent: _remoteConversationRecordKey,
-            crypto: _messagesCrypto),
+            crypto: _conversationCrypto),
         decodeElement: proto.Message.fromBuffer);
     _rcvdSubscription =
         _rcvdMessagesCubit!.stream.listen(_updateRcvdMessagesState);
@@ -222,31 +219,6 @@ class SingleContactMessagesCubit extends Cubit<SingleContactMessagesState> {
     _renderState();
   }
 
-  Future<Uint8List> _hashSignature(proto.Signature signature) async =>
-      (await _localMessagesCryptoSystem
-              .generateHash(signature.toVeilid().decode()))
-          .decode();
-
-  Future<void> _signMessage(proto.Message message) async {
-    // Generate data to sign
-    final data = Uint8List.fromList(utf8.encode(message.writeToJson()));
-
-    // Sign with our identity
-    final signature = await _identityCryptoSystem.sign(
-        _activeAccountInfo.localAccount.identityMaster.identityPublicKey,
-        _activeAccountInfo.userLogin.identitySecret.value,
-        data);
-
-    // Add to the message
-    message.signature = signature.toProto();
-  }
-
-  Future<Uint8List> _generateInitialId(
-          {required PublicKey identityPublicKey}) async =>
-      (await _localMessagesCryptoSystem
-              .generateHash(identityPublicKey.decode()))
-          .decode();
-
   Future<void> _processMessageToSend(
       proto.Message message, proto.Message? previousMessage) async {
     // Get the previous message if we don't have one
@@ -255,20 +227,12 @@ class SingleContactMessagesCubit extends Cubit<SingleContactMessagesState> {
             ? null
             : await r.getProtobuf(proto.Message.fromBuffer, r.length - 1));
 
-    if (previousMessage == null) {
-      // If there's no last sent message,
-      // we start at a hash of the identity public key
-      message.id = await _generateInitialId(
-          identityPublicKey:
-              _activeAccountInfo.localAccount.identityMaster.identityPublicKey);
-    } else {
-      // If there is a last message, we generate the hash
-      // of the last message's signature and use it as our next id
-      message.id = await _hashSignature(previousMessage.signature);
-    }
+    message.id =
+        await _senderMessageIntegrity.generateMessageId(previousMessage);
 
     // Now sign it
-    await _signMessage(message);
+    await _senderMessageIntegrity.signMessage(
+        message, _activeAccountInfo.userLogin.identitySecret.value);
   }
 
   // Async process to send messages in the background
@@ -303,17 +267,17 @@ class SingleContactMessagesCubit extends Cubit<SingleContactMessagesState> {
 
     // Generate state for each message
     final sentMessagesMap =
-        IMap<String, DHTLogElementState<proto.Message>>.fromValues(
-      keyMapper: (x) => x.value.uniqueIdString,
+        IMap<String, OnlineElementState<proto.Message>>.fromValues(
+      keyMapper: (x) => x.value.authorUniqueIdString,
       values: sentMessages.elements,
     );
     final reconciledMessagesMap =
         IMap<String, proto.ReconciledMessage>.fromValues(
-      keyMapper: (x) => x.content.uniqueIdString,
+      keyMapper: (x) => x.content.authorUniqueIdString,
       values: reconciledMessages.elements,
     );
     final sendingMessagesMap = IMap<String, proto.Message>.fromValues(
-      keyMapper: (x) => x.uniqueIdString,
+      keyMapper: (x) => x.authorUniqueIdString,
       values: sendingMessages,
     );
 
@@ -405,9 +369,8 @@ class SingleContactMessagesCubit extends Cubit<SingleContactMessagesState> {
   final TypedKey _remoteConversationRecordKey;
   final TypedKey _remoteMessagesRecordKey;
 
-  late final VeilidCrypto _messagesCrypto;
-  late final VeilidCryptoSystem _localMessagesCryptoSystem;
-  late final VeilidCryptoSystem _identityCryptoSystem;
+  late final VeilidCrypto _conversationCrypto;
+  late final MessageIntegrity _senderMessageIntegrity;
 
   DHTLogCubit<proto.Message>? _sentMessagesCubit;
   DHTLogCubit<proto.Message>? _rcvdMessagesCubit;

lib/chat/views/chat_component.dart

@@ -127,7 +127,7 @@ class ChatComponent extends StatelessWidget {
             author: isLocal ? _localUser : _remoteUser,
             createdAt:
                 (message.sentTimestamp.value ~/ BigInt.from(1000)).toInt(),
-            id: message.content.uniqueIdString,
+            id: message.content.authorUniqueIdString,
             text: contextText.text,
             showStatus: status != null,
             status: status);

lib/proto/extensions.dart

@@ -16,13 +16,15 @@ Map<String, dynamic> reconciledMessageToJson(proto.ReconciledMessage m) =>
     m.writeToJsonMap();
 
 extension MessageExt on proto.Message {
-  Uint8List get uniqueIdBytes {
+  Uint8List get idBytes => Uint8List.fromList(id);
+
+  Uint8List get authorUniqueIdBytes {
     final author = this.author.toVeilid().decode();
     final id = this.id;
     return Uint8List.fromList([...author, ...id]);
   }
 
-  String get uniqueIdString => base64UrlNoPadEncode(uniqueIdBytes);
+  String get authorUniqueIdString => base64UrlNoPadEncode(authorUniqueIdBytes);
 
   static int compareTimestamp(proto.Message a, proto.Message b) =>
       a.timestamp.compareTo(b.timestamp);

packages/veilid_support/lib/dht_support/src/dht_log/dht_log_cubit.dart

@@ -9,16 +9,6 @@ import 'package:meta/meta.dart';
 
 import '../../../veilid_support.dart';
 
-@immutable
-class DHTLogElementState<T> extends Equatable {
-  const DHTLogElementState({required this.value, required this.isOffline});
-  final T value;
-  final bool isOffline;
-
-  @override
-  List<Object?> get props => [value, isOffline];
-}
-
 @immutable
 class DHTLogStateData<T> extends Equatable {
   const DHTLogStateData(
@@ -28,7 +18,7 @@ class DHTLogStateData<T> extends Equatable {
       required this.follow});
   // The view of the elements in the dhtlog
   // Span is from [tail-length, tail)
-  final IList<DHTLogElementState<T>> elements;
+  final IList<OnlineElementState<T>> elements;
   // One past the end of the last element
   final int tail;
   // The total number of elements to try to keep in 'elements'
@@ -92,7 +82,8 @@ class DHTLogCubit<T> extends Cubit<DHTLogBusyState<T>>
 
   Future<void> _refreshInner(void Function(AsyncValue<DHTLogStateData<T>>) emit,
       {bool forceRefresh = false}) async {
-    final avElements = await loadElements(_tail, _count);
+    final avElements = await operate(
+        (reader) => loadElementsFromReader(reader, _tail, _count));
     final err = avElements.asError;
     if (err != null) {
       emit(AsyncValue.error(err.error, err.stackTrace));
@@ -109,26 +100,22 @@ class DHTLogCubit<T> extends Cubit<DHTLogBusyState<T>>
   }
 
   // Tail is one past the last element to load
-  Future<AsyncValue<IList<DHTLogElementState<T>>>> loadElements(
-      int tail, int count,
+  Future<AsyncValue<IList<OnlineElementState<T>>>> loadElementsFromReader(
+      DHTLogReadOperations reader, int tail, int count,
       {bool forceRefresh = false}) async {
-    await _initWait();
     try {
-      final allItems = await _log.operate((reader) async {
-        final length = reader.length;
-        final end = ((tail - 1) % length) + 1;
-        final start = (count < end) ? end - count : 0;
+      final length = reader.length;
+      final end = ((tail - 1) % length) + 1;
+      final start = (count < end) ? end - count : 0;
 
-        final offlinePositions = await reader.getOfflinePositions();
-        final allItems = (await reader.getRange(start,
-                length: end - start, forceRefresh: forceRefresh))
-            ?.indexed
-            .map((x) => DHTLogElementState(
-                value: _decodeElement(x.$2),
-                isOffline: offlinePositions.contains(x.$1)))
-            .toIList();
-        return allItems;
-      });
+      final offlinePositions = await reader.getOfflinePositions();
+      final allItems = (await reader.getRange(start,
+              length: end - start, forceRefresh: forceRefresh))
+          ?.indexed
+          .map((x) => OnlineElementState(
+              value: _decodeElement(x.$2),
+              isOffline: offlinePositions.contains(x.$1)))
+          .toIList();
       if (allItems == null) {
         return const AsyncValue.loading();
       }

packages/veilid_support/lib/src/online_element_state.dart

@@ -0,0 +1,12 @@
+import 'package:equatable/equatable.dart';
+import 'package:meta/meta.dart';
+
+@immutable
+class OnlineElementState<T> extends Equatable {
+  const OnlineElementState({required this.value, required this.isOffline});
+  final T value;
+  final bool isOffline;
+
+  @override
+  List<Object?> get props => [value, isOffline];
+}

packages/veilid_support/lib/veilid_support.dart

@@ -10,6 +10,7 @@ export 'src/config.dart';
 export 'src/identity.dart';
 export 'src/json_tools.dart';
 export 'src/memory_tools.dart';
+export 'src/online_element_state.dart';
 export 'src/output.dart';
 export 'src/persistent_queue.dart';
 export 'src/protobuf_tools.dart';