Feat/federated nodes

.gitignore

@@ -47,4 +47,5 @@ app.*.map.json
 # FVM Version Cache
 .fvm/
 
-.vscode/
+.vscode/
+android/.kotlin/

ios/Flutter/Debug.xcconfig

@@ -1 +1,2 @@
+#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
 #include "Generated.xcconfig"

ios/Flutter/Release.xcconfig

@@ -1 +1,2 @@
+#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
 #include "Generated.xcconfig"

ios/Podfile

@@ -0,0 +1,43 @@
+# Uncomment this line to define a global platform for your project
+# platform :ios, '13.0'
+
+# CocoaPods analytics sends network stats synchronously affecting flutter build latency.
+ENV['COCOAPODS_DISABLE_STATS'] = 'true'
+
+project 'Runner', {
+  'Debug' => :debug,
+  'Profile' => :release,
+  'Release' => :release,
+}
+
+def flutter_root
+  generated_xcode_build_settings_path = File.expand_path(File.join('..', 'Flutter', 'Generated.xcconfig'), __FILE__)
+  unless File.exist?(generated_xcode_build_settings_path)
+    raise "#{generated_xcode_build_settings_path} must exist. If you're running pod install manually, make sure flutter pub get is executed first"
+  end
+
+  File.foreach(generated_xcode_build_settings_path) do |line|
+    matches = line.match(/FLUTTER_ROOT\=(.*)/)
+    return matches[1].strip if matches
+  end
+  raise "FLUTTER_ROOT not found in #{generated_xcode_build_settings_path}. Try deleting Generated.xcconfig, then run flutter pub get"
+end
+
+require File.expand_path(File.join('packages', 'flutter_tools', 'bin', 'podhelper'), flutter_root)
+
+flutter_ios_podfile_setup
+
+target 'Runner' do
+  use_frameworks!
+
+  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
+  target 'RunnerTests' do
+    inherit! :search_paths
+  end
+end
+
+post_install do |installer|
+  installer.pods_project.targets.each do |target|
+    flutter_additional_ios_build_settings(target)
+  end
+end

lib/data/node/sessions/create_session.dart

@@ -6,8 +6,17 @@ import 'package:flutter/material.dart';
 import 'package:hushnet_frontend/services/key_provider.dart';
 import 'package:hushnet_frontend/services/node_service.dart';
 
-/// Full X3DH + initial AES-GCM encrypt for each recipient device, then POST /sessions
-Future<bool> createSession(String nodeUrl, String recipientUserId) async {
+/// Full X3DH + initial AES-GCM encrypt for each recipient device, then POST /sessions.
+///
+/// Pass [recipientUserAddress] (e.g. "bob@node-b.hushnet.net") for federated
+/// users. The local node proxies key fetching and session forwarding.
+/// [recipientUserId] is ignored server-side for remote recipients; pass the
+/// nil UUID as a placeholder when you only have the federated address.
+Future<bool> createSession(
+  String nodeUrl,
+  String recipientUserId, {
+  String? recipientUserAddress,
+}) async {
   final keyProvider = KeyProvider();
   final dio = Dio();
   final NodeService nodeService = NodeService();
@@ -22,8 +31,11 @@ Future<bool> createSession(String nodeUrl, String recipientUserId) async {
       throw Exception('Missing identity or prekey on client');
     }
 
-    // 2) get recipient devices (assumes these return X25519 pubs)
-    final devices = await keyProvider.getUserDevicesKeys(recipientUserId);
+    // 2) get recipient devices — federated path uses the proxy endpoint
+    final devices = recipientUserAddress != null
+        ? await keyProvider.getRemoteUserDevicesKeys(recipientUserAddress)
+        : await keyProvider.getUserDevicesKeys(recipientUserId);
+
     if (devices.isEmpty) {
       debugPrint('No devices for recipient');
       return false;
@@ -192,7 +204,7 @@ Future<bool> createSession(String nodeUrl, String recipientUserId) async {
       final nonce = aes.newNonce();
       final plaintext = utf8.encode(
         'HushNet initial session message',
-      ); // customize initial message as needed
+      );
       final secretBox = await aes.encrypt(
         plaintext,
         secretKey: rootKey,
@@ -211,9 +223,8 @@ Future<bool> createSession(String nodeUrl, String recipientUserId) async {
       sessionsInit.add({
         'recipient_device_id': device.deviceId,
         'ephemeral_pubkey': ekPubB64,
-        'sender_identity_pub': base64Encode(ikPub),
         'ciphertext': ciphertextB64,
-        'otpk_used': device.oneTimePrekeyPub,
+        'otpk_used': device.oneTimePrekeyPub ?? '',
         'sender_prekey_pub': base64Encode(ikPub),
       });
     } // end for devices
@@ -245,6 +256,8 @@ Future<bool> createSession(String nodeUrl, String recipientUserId) async {
 
     final payload = {
       'recipient_user_id': recipientUserId,
+      if (recipientUserAddress != null)
+        'recipient_user_address': recipientUserAddress,
       'sessions_init': sessionsInit,
     };
 
@@ -254,7 +267,8 @@ Future<bool> createSession(String nodeUrl, String recipientUserId) async {
       options: Options(headers: headers),
     );
 
-    if (res.statusCode == 200 || res.statusCode == 201) {
+    // 202 means the session was forwarded to the remote node — treat as success
+    if (res.statusCode == 200 || res.statusCode == 201 || res.statusCode == 202) {
       return true;
     } else {
       debugPrint('CreateSessionFull failed http: ${res.statusCode} ${res.data}');

lib/main.dart

@@ -42,7 +42,6 @@ class MyHomePage extends StatefulWidget {
 }
 
 class _MyHomePageState extends State<MyHomePage> {
-
   @override
   Widget build(BuildContext context) {
     return const OnboardingScreen();

lib/models/chat_view.dart

@@ -10,6 +10,8 @@ class ChatView {
   final String? lastMessagePreview;
   final DateTime updatedAt;
   final String displayName;
+  // Populated by server for federated chats (partner_federated_address).
+  final String? federatedAddress;
 
   ChatView({
     required this.id,
@@ -21,8 +23,11 @@ class ChatView {
     this.lastMessagePreview,
     required this.updatedAt,
     this.displayName = '',
+    this.federatedAddress,
   });
 
+  bool get isRemote => federatedAddress != null;
+
   factory ChatView.fromJson(Map<String, dynamic> json) {
     return ChatView(
       id: json['id'] ?? '',
@@ -34,6 +39,22 @@ class ChatView {
       lastMessagePreview: json['last_message_preview'],
       updatedAt: DateTime.parse(json['updated_at']),
       displayName: json['name'] ?? json['partner_username'] ?? '',
+      federatedAddress: json['partner_federated_address'],
+    );
+  }
+
+  ChatView copyWith({String? federatedAddress}) {
+    return ChatView(
+      id: id,
+      chatType: chatType,
+      partnerUserId: partnerUserId,
+      partnerUsername: partnerUsername,
+      name: name,
+      lastMessageId: lastMessageId,
+      lastMessagePreview: lastMessagePreview,
+      updatedAt: updatedAt,
+      displayName: displayName,
+      federatedAddress: federatedAddress ?? this.federatedAddress,
     );
   }
 
@@ -47,15 +68,14 @@ class ChatView {
       'last_message_id': lastMessageId,
       'last_message_preview': lastMessagePreview,
       'updated_at': updatedAt.toIso8601String(),
+      if (federatedAddress != null) 'partner_federated_address': federatedAddress,
     };
   }
 
-  /// Optional helper: format the last update nicely for UI
   String get formattedDate {
     return DateFormat('dd/MM HH:mm').format(updatedAt);
   }
 
-  /// Optional helper: title shown in chat list
   String get displayTitle {
     if (chatType == 'group') return name ?? 'Group chat';
     return partnerUsername ?? 'Unknown';

lib/models/pending_sessions.dart

@@ -7,9 +7,10 @@ class PendingSession {
   final String ephemeralPubkey; // base64
   final String ciphertext; // base64
   final String? senderPrekeyPub; // base64 (nécessaire pour DH1)
+  final String? otpkUsed; // base64 public key of the OPK Alice used
   final String createdAt;
   User? senderUser;
-  
+
   PendingSession({
     required this.id,
     required this.senderDeviceId,
@@ -19,6 +20,7 @@ class PendingSession {
     required this.createdAt,
     this.senderUser,
     this.senderPrekeyPub,
+    this.otpkUsed,
   });
 
   factory PendingSession.fromJson(Map<String, dynamic> json) {
@@ -30,6 +32,9 @@ class PendingSession {
       ciphertext: json['ciphertext'],
       createdAt: json['created_at'] ?? '',
       senderPrekeyPub: json['sender_prekey_pub'],
+      otpkUsed: json['otpk_used'] is String && (json['otpk_used'] as String).isNotEmpty
+          ? json['otpk_used']
+          : null,
     );
   }
 }

lib/models/user_device.dart

@@ -22,20 +22,45 @@ class UserDevice {
       deviceId: json['id'] ?? json['device_id'],
       identityPubkey: json['identity_pubkey'],
       prekeyPubkey: json['prekey_pubkey'] ?? json['prekey']?['key'],
-      signedPrekeyPub: json['signed_prekey_pub'] ?? json['signed_prekey']?['key'],
-      signedPrekeySig: json['signed_prekey_sig'] ?? json['signed_prekey']?['signature'],
-      oneTimePrekeyPub: json['one_time_prekeys'][0] ?? json['one_time_prekey']?['key'],
+      signedPrekeyPub:
+          json['signed_prekey_pub'] ?? json['signed_prekey']?['key'],
+      signedPrekeySig:
+          json['signed_prekey_sig'] ?? json['signed_prekey']?['signature'],
+      oneTimePrekeyPub:
+          json['one_time_prekeys'][0] ?? json['one_time_prekey']?['key'],
+    );
+  }
+
+  // Federated endpoint returns a slightly different shape:
+  //   device_id, identity_pubkey, signed_prekey_pub, signed_prekey_sig,
+  //   one_time_prekeys: ["base64", ...]  (strings, not objects)
+  factory UserDevice.fromFederatedJson(Map<String, dynamic> json) {
+    final otpks = json['one_time_prekeys'];
+    String? otpk;
+    if (otpks is List && otpks.isNotEmpty) {
+      final first = otpks[0];
+      otpk = first is String
+          ? first
+          : (first is Map ? first['key'] as String? : null);
+    }
+    return UserDevice(
+      deviceId: json['device_id'] ?? json['id'],
+      identityPubkey: json['identity_pubkey'],
+      prekeyPubkey: json['prekey_pubkey'],
+      signedPrekeyPub: json['signed_prekey_pub'],
+      signedPrekeySig: json['signed_prekey_sig'],
+      oneTimePrekeyPub: otpk,
     );
   }
 
   Map<String, dynamic> toJson() => {
-        'device_id': deviceId,
-        'prekey_pubkey': prekeyPubkey,
-        'identity_pubkey': identityPubkey,
-        'signed_prekey_pub': signedPrekeyPub,
-        'signed_prekey_sig': signedPrekeySig,
-        'one_time_prekey_pub': oneTimePrekeyPub,
-      };
+    'device_id': deviceId,
+    'prekey_pubkey': prekeyPubkey,
+    'identity_pubkey': identityPubkey,
+    'signed_prekey_pub': signedPrekeyPub,
+    'signed_prekey_sig': signedPrekeySig,
+    'one_time_prekey_pub': oneTimePrekeyPub,
+  };
 
   @override
   String toString() => jsonEncode(toJson());