feat(e2e): 端对端加密完全对齐老项目 — cipher_guard_sdk 修正 + EncryptionManager 集成

修正 cipher_guard_sdk 4 个关键密码学差异使其与老 Flutter 项目 (im-client-im-dev) 和 iOS
EncryptionManager 完全互操作：

1. AES: 显式 SIC/CTR 模式 + 16 zero-byte IV（原 SDK 用随机 IV + KDF 派生密钥）
2. RSA: bare RSAEngine 无 PKCS1 padding（原 SDK 用 PKCS1Encoding）
3. Session key: 32-char alphanumeric ASCII（原 SDK 用 base64 random bytes）
4. Wire format: base64(ciphertext) 无 IV 前缀

新增 EncryptionManager：
- Per-chat round-based key chain（最多 10 rounds/chat，FIFO 淘汰）
- 登录后自动 setup：RSA 密钥对生成/存储 + 公钥上传 + chat 密钥拉取解密
- API 集成：cipher/v2/key/my, key/set, chat/my
- 消息加密返回 JSON envelope {"round":N,"data":"<base64>"}
- 消息解密兼容 JSON envelope + legacy raw base64

集成到消息流：
- SendMessageUseCase: 发送前加密 content → wireContent
- WsMessageService: 收到消息后解密 content + lastMsg
- 无密钥时 fallback 到明文（对齐 iOS 行为）

注意：/app/api/cipher/v2/key/set 仍为预发布接口，仅测试阶段使用

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/im_app/lib/app/di/app_providers.dart

@@ -1,8 +1,10 @@
+import 'package:cipher_guard_sdk/cipher_guard_sdk.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 import 'package:im_app/core/foundation/device_info.dart';
 import 'package:im_app/core/services/app_initializer.dart';
+import 'package:im_app/core/services/encryption_manager.dart';
 import 'package:im_app/app/di/network_provider.dart';
 
 // ── 认证 ──────────────────────────────────────────────────────────────────────
@@ -26,32 +28,60 @@ class AuthNotifier extends ChangeNotifier {
   /// 登录用户的 UID，登录成功后由 LoginViewModel 写入
   int? get currentUid => _currentUid;
 
+  /// E2E EncryptionManager — 由外部注入（见 LoginViewModel）
+  EncryptionManager? _encryptionManager;
+  NetworksSdkApi? _api;
+
+  void setEncryptionDeps(EncryptionManager encMgr, NetworksSdkApi api) {
+    _encryptionManager = encMgr;
+    _api = api;
+  }
+
   void login({required int uid}) {
     _isLoggedIn = true;
     _currentUid = uid;
-    // TODO: 接入 cipher_guard_sdk 后，在此处完成 RSA 密钥注入：
-    // 1. 从安全存储（keychain / secure storage）读取公私钥对（只读一次）
-    // 2. cipherSdk.setActiveKeyPair(publicKey: pubPem, privateKey: privPem)
-    // 须在 notifyListeners() 之前完成，确保路由跳转后 onEncryptRequest 回调触发时密钥已就绪。
     notifyListeners();
+    // E2E setup: 对齐 iOS AppCoordinator.onLogin → EncryptionManager.setup()
+    if (_encryptionManager != null && _api != null) {
+      _encryptionManager!.setup(_api!);
+    }
   }
 
   void logout() {
     _isLoggedIn = false;
     _currentUid = null;
-    // TODO: 接入 cipher_guard_sdk 后，退出登录时清除内存密钥：
-    // cipherSdk.clearActiveKeyPair()
-    // cipherSdk.clearDerivedKeyCache()
+    // E2E teardown: 清除所有加密密钥
+    _encryptionManager?.clearKeys();
     notifyListeners();
   }
 }
 
 /// 登录状态 Provider
 ///
-/// 使用 [Provider] 持有 [AuthNotifier] 单例。
-/// go_router 通过 [GoRouter.refreshListenable] 直接监听 [AuthNotifier]（ChangeNotifier），
-/// Riverpod 侧不需要响应式更新（导航由 go_router 接管）。
-final authNotifierProvider = Provider<AuthNotifier>((ref) => AuthNotifier());
+/// 自动注入 EncryptionManager + API client，login() 后自动触发 E2E setup。
+final authNotifierProvider = Provider<AuthNotifier>((ref) {
+  final auth = AuthNotifier();
+  auth.setEncryptionDeps(
+    ref.read(encryptionManagerProvider),
+    ref.read(networkSdkApiProvider),
+  );
+  return auth;
+});
+
+// ── E2E 加密 ────────────────────────────────────────────────────────────────
+
+/// CipherGuardSdkApi 单例 — 对齐老项目加密引擎
+final cipherSdkProvider = Provider<CipherGuardSdkApi>((ref) {
+  return CipherGuardSdkApi();
+});
+
+/// EncryptionManager 单例 — per-chat key chain + API integration
+///
+/// 登录后调用 `encMgr.setup(api)` 启动 E2E，退出时调用 `encMgr.clearKeys()`。
+/// 对齐 iOS EncryptionManager + 老项目 EncryptionMgr。
+final encryptionManagerProvider = Provider<EncryptionManager>((ref) {
+  return EncryptionManager(cipherSdk: ref.read(cipherSdkProvider));
+});
 
 // ── 主题 ──────────────────────────────────────────────────────────────────────
 

apps/im_app/lib/core/foundation/api_paths.dart

@@ -56,6 +56,18 @@ class ApiPaths {
   static const favoriteFetchByIds = '/app/api/favorite/favorite';
   static const favoriteTags = '/app/api/favorite/tags';
 
+  // ── Cipher (E2E Encryption) ──
+  // 注意：/app/api/cipher/v2/key/set 是预发布接口，仅测试阶段使用
+  static const cipherKeyMy = '/app/api/cipher/v2/key/my';
+  static const cipherKeySet = '/app/api/cipher/v2/key/set';
+  static const cipherKeyGets = '/app/api/cipher/v2/key/gets';
+  static const cipherChatGet = '/app/api/cipher/v2/chat/get';
+  static const cipherChatMy = '/app/api/cipher/v2/chat/my';
+  static const cipherChatUpdate = '/app/api/cipher/v2/chat/update';
+  static const cipherChatRequest = '/app/api/cipher/v2/chat/request';
+  static const cipherChatSessionsExist =
+      '/app/api/cipher/v2/chat/sessions_exist';
+
   // ── WebSocket ──
   static const wsConnect = '/websock/open';
 }

apps/im_app/lib/core/services/encryption_manager.dart

@@ -0,0 +1,335 @@
+import 'dart:convert';
+
+import 'package:cipher_guard_sdk/cipher_guard_sdk.dart';
+import 'package:flutter/foundation.dart';
+import 'package:networks_sdk/networks_sdk.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+import 'package:im_app/data/remote/cipher_api_requests.dart';
+
+/// Per-chat AES key manager with round-based key chain — 对齐 iOS EncryptionManager
+///
+/// 协议（对齐老项目 im-client-im-dev EncryptionMgr + iOS EncryptionManager）：
+///   1. RSA-1024 key pair: 生成一次，私钥存 secure storage
+///   2. 公钥上传到服务器: POST /app/api/cipher/v2/key/set
+///   3. 所有聊天 cipher session 获取: GET /app/api/cipher/v2/chat/my
+///      服务器返回 [{ chat_id, session: Base64(RSA_raw_encrypt(32-char AES key)), round }]
+///   4. 每个 session 用 RSA 私钥解密 → 32-char AES key per chat
+///   5. 消息加解密:
+///      Wire format (new): JSON {"round": N, "data": "<Base64 AES-SIC ciphertext>"}
+///      Legacy format: raw Base64 ciphertext (无 round — 使用该 chat 最新 key)
+///      AES-256 SIC/CTR mode, key = UTF-8(32-char key), IV = 16 zero bytes
+///
+/// Key chain:
+///   keyChain[chatId][round] = aesKey (32-char string)
+///   最多 maxKeyChainDepth(10) rounds per chat; 最旧的 round 先被淘汰
+///   Key chain 持久化到 secure storage 作为 JSON
+class EncryptionManager {
+  EncryptionManager({
+    required CipherGuardSdkApi cipherSdk,
+  }) : _cipherSdk = cipherSdk;
+
+  final CipherGuardSdkApi _cipherSdk;
+
+  // chatId → (round → 32-char AES key)
+  final Map<int, Map<int, String>> _keyChain = {};
+
+  bool _isSetup = false;
+  bool _isSettingUp = false;
+
+  static const int maxKeyChainDepth = 10;
+
+  // 对齐老项目 EncryptionMgr：使用 localStorageMgr (SharedPreferences) 存储密钥。
+  // TODO(security): 迁移到 flutter_secure_storage 使用 Keychain/Keystore。
+  static const String _keyChainStorageKey = 'enc.keychain.json';
+  static const String _rsaPublicKeyStorageKey = 'enc.rsa.public';
+  static const String _rsaPrivateKeyStorageKey = 'enc.rsa.private';
+
+  bool get isSetup => _isSetup;
+
+  // ── Teardown ──────────────────────────────────────────────────────────────
+
+  Future<void> clearKeys() async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.remove(_rsaPublicKeyStorageKey);
+    await prefs.remove(_rsaPrivateKeyStorageKey);
+    await prefs.remove(_keyChainStorageKey);
+    _keyChain.clear();
+    _isSetup = false;
+    _cipherSdk.clearActiveKeyPair();
+    debugPrint('[EncMgr] all keys cleared');
+  }
+
+  // ── Setup ─────────────────────────────────────────────────────────────────
+
+  /// Call once after login. Idempotent.
+  Future<void> setup(NetworksSdkApi api) async {
+    if (_isSetup || _isSettingUp) return;
+    _isSettingUp = true;
+    try {
+      // 1. Load or generate RSA key pair
+      final prefs = await SharedPreferences.getInstance();
+      var publicPem = prefs.getString(_rsaPublicKeyStorageKey);
+      var privatePem = prefs.getString(_rsaPrivateKeyStorageKey);
+
+      if (publicPem == null || privatePem == null) {
+        debugPrint('[EncMgr] generating RSA-1024 key pair...');
+        final keyPair = await _cipherSdk.generateRsaKeyPair(keySize: 1024);
+        publicPem = keyPair.publicKey;
+        privatePem = keyPair.privateKey;
+        await prefs.setString(_rsaPublicKeyStorageKey, publicPem);
+        await prefs.setString(_rsaPrivateKeyStorageKey, privatePem);
+        debugPrint('[EncMgr] RSA key pair stored');
+      }
+
+      // Inject into cipher SDK for session key encrypt/decrypt
+      _cipherSdk.setActiveKeyPair(
+          publicKey: publicPem, privateKey: privatePem);
+
+      // 2. Upload public key if server doesn't have one
+      await _uploadPublicKeyIfNeeded(api, publicPem, privatePem);
+
+      // 3. Load existing key chain from secure storage
+      await _loadKeyChainFromStorage();
+
+      // 4. Fetch and decrypt all chat keys from server
+      final success = await _fetchAndDecryptAllChatKeys(api);
+      if (success) {
+        _isSetup = true;
+        debugPrint('[EncMgr] setup complete, ${_keyChain.length} chats loaded');
+      }
+    } catch (e) {
+      debugPrint('[EncMgr] setup failed: $e');
+    } finally {
+      _isSettingUp = false;
+    }
+  }
+
+  // ── Round / key chain API ─────────────────────────────────────────────────
+
+  /// Current active round for a chat (highest round number), or null.
+  int? currentRound(int chatId) {
+    final rounds = _keyChain[chatId];
+    if (rounds == null || rounds.isEmpty) return null;
+    return rounds.keys.reduce((a, b) => a > b ? a : b);
+  }
+
+  /// Retrieve a specific round's AES key.
+  String? chatKey(int chatId, {int? round}) {
+    final rounds = _keyChain[chatId];
+    if (rounds == null || rounds.isEmpty) return null;
+    if (round != null) return rounds[round];
+    // No round specified — return latest
+    final latest = rounds.keys.reduce((a, b) => a > b ? a : b);
+    return rounds[latest];
+  }
+
+  // ── Encrypt / Decrypt API ─────────────────────────────────────────────────
+
+  /// AES-SIC encrypt plaintext for a chat.
+  /// Returns JSON `{"round":N,"data":"<base64>"}`, or null if no key.
+  ///
+  /// 对齐 iOS EncryptionManager.encryptContent()
+  Future<String?> encryptContent(String plaintext, {required int chatId}) async {
+    final round = currentRound(chatId);
+    if (round == null) return null;
+    final key = _keyChain[chatId]?[round];
+    if (key == null) return null;
+
+    try {
+      final result = await _cipherSdk.encryptMessage(
+        plaintext: plaintext,
+        sessionKey: key,
+        round: round,
+      );
+      // Build JSON envelope matching iOS format
+      return jsonEncode({'round': round, 'data': result.data});
+    } catch (e) {
+      debugPrint('[EncMgr] encrypt failed for chatId=$chatId: $e');
+      return null;
+    }
+  }
+
+  /// Try to AES-SIC decrypt a message's content field.
+  ///
+  /// Accepts two formats:
+  ///   - New: JSON `{"round": N, "data": "<base64>"}` — uses round-specific key
+  ///   - Legacy: raw Base64 ciphertext — uses latest key for the chat
+  ///
+  /// Returns null if no suitable key or decryption fails.
+  Future<String?> decryptContent(String content, {required int chatId}) async {
+    // Try new JSON envelope format first
+    try {
+      final obj = jsonDecode(content);
+      if (obj is Map<String, dynamic> &&
+          obj.containsKey('round') &&
+          obj.containsKey('data')) {
+        final round = obj['round'] as int;
+        final b64Data = obj['data'] as String;
+        final key = _keyChain[chatId]?[round];
+        if (key == null) {
+          debugPrint(
+              '[EncMgr] decrypt: round=$round key missing for chatId=$chatId');
+          return null; // caller should mark ref_typ=4
+        }
+        return await _cipherSdk.decryptMessage(
+          encryptedData: b64Data,
+          sessionKey: key,
+          round: round,
+        );
+      }
+    } catch (_) {
+      // Not JSON — try legacy format
+    }
+
+    // Legacy: raw Base64 — use latest key
+    final key = chatKey(chatId);
+    if (key == null) return null;
+    final round = currentRound(chatId) ?? 0;
+    try {
+      return await _cipherSdk.decryptMessage(
+        encryptedData: content,
+        sessionKey: key,
+        round: round,
+      );
+    } catch (e) {
+      debugPrint('[EncMgr] legacy decrypt failed for chatId=$chatId: $e');
+      return null;
+    }
+  }
+
+  // ── Private: server API ───────────────────────────────────────────────────
+
+  Future<void> _uploadPublicKeyIfNeeded(
+    NetworksSdkApi api,
+    String publicPem,
+    String privatePem,
+  ) async {
+    try {
+      // Check if server already has a key
+      final resp = await api.executeRequest(CipherGetMyKeyRequest());
+      if (resp != null && resp.publicKey.isNotEmpty) {
+        debugPrint('[EncMgr] server already has public key, skipping upload');
+        return;
+      }
+    } catch (e) {
+      debugPrint('[EncMgr] key/my check failed: $e');
+      // Continue — attempt upload anyway
+    }
+
+    // enc_pk: encrypted private key backup (对齐 iOS — uses raw PEM as placeholder)
+    final encPk = await _cipherSdk.encryptPrivateKey(
+      privateKey: privatePem,
+      password: 'default', // placeholder, same as old project demo
+    );
+
+    try {
+      await api.executeRequest(
+        CipherSetKeyRequest(publicKey: publicPem, encPk: encPk),
+      );
+      debugPrint('[EncMgr] public key uploaded OK');
+    } catch (e) {
+      debugPrint('[EncMgr] key/set upload failed: $e');
+    }
+  }
+
+  Future<bool> _fetchAndDecryptAllChatKeys(NetworksSdkApi api) async {
+    try {
+      final chatKeys = await api.executeRequest(CipherGetMyChatKeysRequest());
+      if (chatKeys == null || chatKeys.isEmpty) {
+        debugPrint('[EncMgr] no chat keys from server');
+        return true; // Empty is OK
+      }
+
+      for (final ck in chatKeys) {
+        if (ck.session == null || ck.session!.isEmpty) continue;
+        try {
+          // RSA raw decrypt the session → 32-char AES key
+          final decryptedKey =
+              await _cipherSdk.decryptSessionKeyWithActiveKey(
+            encryptedSessionKey: ck.session!,
+          );
+          // Strip leading null bytes (RSA raw output may have leading zeros)
+          final cleanKey = _stripLeadingZeros(decryptedKey);
+          if (cleanKey.length == 32) {
+            _storeKey(cleanKey, ck.chatId ?? 0, ck.round ?? 0);
+          } else {
+            debugPrint(
+                '[EncMgr] key length ${cleanKey.length} != 32 for chatId=${ck.chatId}');
+          }
+        } catch (e) {
+          debugPrint(
+              '[EncMgr] RSA decrypt failed for chatId=${ck.chatId}: $e');
+        }
+      }
+
+      // Persist key chain
+      await _saveKeyChainToStorage();
+      return true;
+    } catch (e) {
+      debugPrint('[EncMgr] fetchAndDecryptAllChatKeys failed: $e');
+      return false;
+    }
+  }
+
+  /// Strip leading zero chars from RSA raw decrypt output
+  String _stripLeadingZeros(String input) {
+    var i = 0;
+    while (i < input.length && input.codeUnitAt(i) == 0) {
+      i++;
+    }
+    return i > 0 ? input.substring(i) : input;
+  }
+
+  void _storeKey(String key, int chatId, int round) {
+    _keyChain.putIfAbsent(chatId, () => {});
+    _keyChain[chatId]![round] = key;
+
+    // Evict oldest rounds if over limit
+    final rounds = _keyChain[chatId]!;
+    while (rounds.length > maxKeyChainDepth) {
+      final oldest = rounds.keys.reduce((a, b) => a < b ? a : b);
+      rounds.remove(oldest);
+    }
+  }
+
+  // ── Key chain persistence ─────────────────────────────────────────────────
+
+  Future<void> _loadKeyChainFromStorage() async {
+    try {
+      final prefs = await SharedPreferences.getInstance();
+      final json = prefs.getString(_keyChainStorageKey);
+      if (json == null || json.isEmpty) return;
+      final decoded = jsonDecode(json) as Map<String, dynamic>;
+      for (final entry in decoded.entries) {
+        final chatId = int.tryParse(entry.key);
+        if (chatId == null) continue;
+        final rounds = entry.value as Map<String, dynamic>;
+        _keyChain[chatId] = {};
+        for (final re in rounds.entries) {
+          final round = int.tryParse(re.key);
+          if (round == null) continue;
+          _keyChain[chatId]![round] = re.value as String;
+        }
+      }
+    } catch (e) {
+      debugPrint('[EncMgr] loadKeyChain failed: $e');
+    }
+  }
+
+  Future<void> _saveKeyChainToStorage() async {
+    try {
+      final serializable = <String, Map<String, String>>{};
+      for (final entry in _keyChain.entries) {
+        serializable[entry.key.toString()] = entry.value.map(
+          (k, v) => MapEntry(k.toString(), v),
+        );
+      }
+      final prefs = await SharedPreferences.getInstance();
+      await prefs.setString(_keyChainStorageKey, jsonEncode(serializable));
+    } catch (e) {
+      debugPrint('[EncMgr] saveKeyChain failed: $e');
+    }
+  }
+}
+

apps/im_app/lib/core/services/ws_message_service.dart

@@ -3,6 +3,7 @@ import 'dart:async';
 import 'package:flutter/foundation.dart';
 import 'package:networks_sdk/networks_sdk.dart';
 
+import 'package:im_app/core/services/encryption_manager.dart';
 import 'package:im_app/core/services/socket_manager.dart';
 import 'package:im_app/core/services/typing_indicator_manager.dart';
 import 'package:im_app/data/remote/fetch_history_request.dart';
@@ -33,6 +34,7 @@ class WsMessageService {
   final MessageRepository _messageRepo;
   final ChatRepository _chatRepo;
   final TypingIndicatorManager _typingManager;
+  final EncryptionManager? _encryptionManager;
 
   StreamSubscription<Map<String, dynamic>>? _sub;
 
@@ -42,11 +44,13 @@ class WsMessageService {
     required MessageRepository messageRepo,
     required ChatRepository chatRepo,
     required TypingIndicatorManager typingManager,
+    EncryptionManager? encryptionManager,
   })  : _socketManager = socketManager,
         _apiClient = apiClient,
         _messageRepo = messageRepo,
         _chatRepo = chatRepo,
-        _typingManager = typingManager;
+        _typingManager = typingManager,
+        _encryptionManager = encryptionManager;
 
   // ── 生命周期 ──────────────────────────────────────────────────────────────
 
@@ -162,7 +166,21 @@ class WsMessageService {
       );
       if (response == null || response.messages.isEmpty) return;
 
-      final entities = response.messages.map((m) => m.toEntity()).toList();
+      // E2E 解密：对齐 iOS MessageReceiver — 收到消息后解密 content
+      var entities = response.messages.map((m) => m.toEntity()).toList();
+      final encMgr = _encryptionManager;
+      if (encMgr != null && encMgr.isSetup) {
+        entities = await Future.wait(entities.map((msg) async {
+          if (msg.content == null || msg.content!.isEmpty) return msg;
+          final decrypted = await encMgr.decryptContent(
+            msg.content!,
+            chatId: chatId,
+          );
+          // decrypted == null → 无法解密或无 key → 保留原文（对齐 iOS fallback）
+          return decrypted != null ? msg.copyWith(content: decrypted) : msg;
+        }));
+      }
+
       await _messageRepo.insertOrReplaceAll(entities);
       debugPrint(
         '[WsMessageService] saved ${entities.length} messages for chat $chatId',
@@ -184,10 +202,23 @@ class WsMessageService {
       final existing = await _chatRepo.getChat(chatId);
       if (existing == null) return;
 
-      final lastMsg = entry['last_msg'] as String?;
+      var lastMsg = entry['last_msg'] as String?;
       final lastTyp = (entry['typ'] as num?)?.toInt();
       final msgIdx = (entry['msg_idx'] as num?)?.toInt();
 
+      // E2E 解密 lastMsg（对齐 iOS ConversationSnippetCache 解密逻辑）
+      final encMgr = _encryptionManager;
+      if (lastMsg != null && lastMsg.isNotEmpty &&
+          encMgr != null && encMgr.isSetup) {
+        final decrypted = await encMgr.decryptContent(lastMsg, chatId: chatId);
+        if (decrypted != null) {
+          lastMsg = decrypted;
+        } else if (lastMsg.startsWith('{')) {
+          // 无法解密且看起来是 JSON 密文 → 不在 UI 显示密文
+          lastMsg = '[Encrypted message]';
+        }
+      }
+
       // 防止乱序帧覆盖新数据（Codex review #4）
       if (msgIdx != null && existing.msgIdx != null && msgIdx < existing.msgIdx!) {
         return;

apps/im_app/lib/data/remote/cipher_api_requests.dart

@@ -0,0 +1,170 @@
+import 'package:networks_sdk/networks_sdk.dart';
+
+/// 对齐老项目 /app/api/cipher/v2/* API 端点
+///
+/// /app/api/cipher/v2/key/set 是预发布接口，仅测试阶段使用。
+
+// ── GET /app/api/cipher/v2/key/my — 获取自己的公钥 ────────────────────────
+
+class CipherMyKeyResponse {
+  final String publicKey;
+  final String? encPrivate;
+  final int? uid;
+
+  const CipherMyKeyResponse({
+    required this.publicKey,
+    this.encPrivate,
+    this.uid,
+  });
+
+  factory CipherMyKeyResponse.fromJson(Map<String, dynamic> json) =>
+      CipherMyKeyResponse(
+        publicKey: (json['public_key'] ?? '') as String,
+        encPrivate: json['enc_pk'] as String?,
+        uid: json['uid'] as int?,
+      );
+}
+
+class CipherGetMyKeyRequest extends ApiRequestable<CipherMyKeyResponse?> {
+  @override
+  String get path => '/app/api/cipher/v2/key/my';
+
+  @override
+  HttpMethod get method => HttpMethod.get;
+
+  @override
+  Map<String, dynamic> get parameters => {};
+
+  @override
+  CipherMyKeyResponse? decodeResponse(dynamic response) {
+    final data = (response as dynamic).data;
+    if (data is! Map<String, dynamic>) return null;
+    return CipherMyKeyResponse.fromJson(data);
+  }
+}
+
+// ── POST /app/api/cipher/v2/key/set — 上传公钥 ─────────────────────────────
+
+class CipherSetKeyRequest extends ApiRequestable<void> {
+  final String publicKey;
+  final String encPk;
+
+  CipherSetKeyRequest({required this.publicKey, required this.encPk});
+
+  @override
+  String get path => '/app/api/cipher/v2/key/set';
+
+  @override
+  HttpMethod get method => HttpMethod.post;
+
+  @override
+  Map<String, dynamic> get parameters => {
+        'public_key': publicKey,
+        'enc_pk': encPk,
+      };
+
+  @override
+  void decodeResponse(dynamic response) {}
+}
+
+// ── GET /app/api/cipher/v2/chat/my — 获取所有聊天的加密密钥 ─────────────────
+
+class CipherChatKeyItem {
+  final int? chatId;
+  final String? session;
+  final int? round;
+
+  const CipherChatKeyItem({this.chatId, this.session, this.round});
+
+  factory CipherChatKeyItem.fromJson(Map<String, dynamic> json) =>
+      CipherChatKeyItem(
+        chatId: json['chat_id'] as int?,
+        session: json['session'] as String?,
+        round: json['round'] as int?,
+      );
+}
+
+class CipherGetMyChatKeysRequest
+    extends ApiRequestable<List<CipherChatKeyItem>?> {
+  @override
+  String get path => '/app/api/cipher/v2/chat/my';
+
+  @override
+  HttpMethod get method => HttpMethod.get;
+
+  @override
+  Map<String, dynamic> get parameters => {};
+
+  @override
+  List<CipherChatKeyItem>? decodeResponse(dynamic response) {
+    final data = (response as dynamic).data;
+    if (data is! List) return null;
+    return data
+        .cast<Map<String, dynamic>>()
+        .map(CipherChatKeyItem.fromJson)
+        .toList();
+  }
+}
+
+// ── GET /app/api/cipher/v2/key/gets — 获取其他用户的公钥 ─────────────────────
+
+class CipherUserKeyResponse {
+  final int? uid;
+  final String? publicKey;
+
+  const CipherUserKeyResponse({this.uid, this.publicKey});
+
+  factory CipherUserKeyResponse.fromJson(Map<String, dynamic> json) =>
+      CipherUserKeyResponse(
+        uid: json['uid'] as int?,
+        publicKey: json['public_key'] as String?,
+      );
+}
+
+class CipherGetUsersKeysRequest
+    extends ApiRequestable<List<CipherUserKeyResponse>?> {
+  final List<int> userIds;
+
+  CipherGetUsersKeysRequest({required this.userIds});
+
+  @override
+  String get path => '/app/api/cipher/v2/key/gets';
+
+  @override
+  HttpMethod get method => HttpMethod.get;
+
+  @override
+  Map<String, dynamic> get parameters => {
+        'uids': userIds.join(','),
+      };
+
+  @override
+  List<CipherUserKeyResponse>? decodeResponse(dynamic response) {
+    final data = (response as dynamic).data;
+    if (data is! List) return null;
+    return data
+        .cast<Map<String, dynamic>>()
+        .map(CipherUserKeyResponse.fromJson)
+        .toList();
+  }
+}
+
+// ── POST /app/api/cipher/v2/chat/update — 更新聊天加密密钥 ──────────────────
+
+class CipherUpdateChatKeysRequest extends ApiRequestable<void> {
+  final List<Map<String, dynamic>> sessions;
+
+  CipherUpdateChatKeysRequest({required this.sessions});
+
+  @override
+  String get path => '/app/api/cipher/v2/chat/update';
+
+  @override
+  HttpMethod get method => HttpMethod.post;
+
+  @override
+  Map<String, dynamic> get parameters => {'sessions': sessions};
+
+  @override
+  void decodeResponse(dynamic response) {}
+}

apps/im_app/lib/features/chat/di/chat_service_providers.dart

@@ -69,6 +69,7 @@ final wsMessageServiceProvider = Provider<WsMessageService>((ref) {
     messageRepo: ref.read(messageRepositoryProvider),
     chatRepo: ref.read(chatRepositoryProvider),
     typingManager: ref.read(typingIndicatorManagerProvider),
+    encryptionManager: ref.read(encryptionManagerProvider),
   );
 
   service.start();
@@ -91,6 +92,7 @@ final sendMessageUseCaseProvider = Provider<SendMessageUseCase>((ref) {
     messageRepo: ref.read(messageRepositoryProvider),
     chatRepo: ref.read(chatRepositoryProvider),
     currentUid: uid,
+    encryptionManager: ref.read(encryptionManagerProvider),
   );
 });
 

apps/im_app/lib/features/chat/usecases/send_message_use_case.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/foundation.dart';
 import 'package:networks_sdk/networks_sdk.dart';
 
+import 'package:im_app/core/services/encryption_manager.dart';
 import 'package:im_app/data/remote/send_message_request.dart';
 import 'package:im_app/domain/entities/message.dart';
 import 'package:im_app/domain/repositories/chat_repository.dart';
@@ -25,6 +26,7 @@ class SendMessageUseCase {
   final NetworksSdkApi _apiClient;
   final MessageRepository _messageRepo;
   final ChatRepository _chatRepo;
+  final EncryptionManager? _encryptionManager;
   final int currentUid;
 
   SendMessageUseCase({
@@ -32,9 +34,11 @@ class SendMessageUseCase {
     required MessageRepository messageRepo,
     required ChatRepository chatRepo,
     required this.currentUid,
+    EncryptionManager? encryptionManager,
   })  : _apiClient = apiClient,
         _messageRepo = messageRepo,
-        _chatRepo = chatRepo;
+        _chatRepo = chatRepo,
+        _encryptionManager = encryptionManager;
 
   Future<void> execute({
     required int chatId,
@@ -56,13 +60,25 @@ class SendMessageUseCase {
       ),
     );
 
-    // 2. HTTP 发送
+    // 2. E2E 加密（对齐 iOS MessageHistoryService.sendMessage）
+    //    wireContent = EncryptionManager.encryptContent(content, chatId) ?? content
+    String wireContent = content;
+    if (_encryptionManager != null && _encryptionManager.isSetup) {
+      final encrypted =
+          await _encryptionManager.encryptContent(content, chatId: chatId);
+      if (encrypted != null) {
+        wireContent = encrypted;
+      }
+      // null = no key for chat → send plaintext (对齐老项目 fallback)
+    }
+
+    // 3. HTTP 发送
     SendMessageResponse? resp;
     try {
       resp = await _apiClient.executeRequest(
         SendMessageRequest(
           chatId: chatId,
-          content: content,
+          content: wireContent,
           typ: typ,
           sendTime: sendTime,
         ),

apps/im_app/pubspec.yaml

@@ -116,6 +116,9 @@ dependencies:
   cached_network_image: ^3.3.1
   crypto: ^3.0.6
 
+  # 本地键值存储（加密 key chain 持久化）
+  shared_preferences: ^2.5.3
+
   # 图片保存到相册（#32）
   image_gallery_saver_plus: ^3.0.5