From 3976b0f1e22461e08fcd339f41a3488b48af1756 Mon Sep 17 00:00:00 2001
From: Christian Pauly <christian-pauly@posteo.de>
Date: Tue, 30 Aug 2022 11:55:17 +0200
Subject: [PATCH] refactor: Avoid using private types in public api

---
 lib/encryption/key_manager.dart | 16 ++++++++--------
 lib/encryption/ssss.dart        | 22 ++++++++++++----------
 2 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/lib/encryption/key_manager.dart b/lib/encryption/key_manager.dart
index 68dbeb99..786a76b5 100644
--- a/lib/encryption/key_manager.dart
+++ b/lib/encryption/key_manager.dart
@@ -771,7 +771,7 @@ class KeyManager {
         }
         final args = GenerateUploadKeysArgs(
           pubkey: backupPubKey,
-          dbSessions: <_DbInboundGroupSessionBundle>[],
+          dbSessions: <DbInboundGroupSessionBundle>[],
           userId: userID,
         );
         // we need to calculate verified beforehand, as else we pass a closure to an isolate
@@ -781,7 +781,7 @@ class KeyManager {
         for (final dbSession in dbSessions) {
           final device =
               client.getUserDeviceKeysByCurve25519Key(dbSession.senderKey);
-          args.dbSessions.add(_DbInboundGroupSessionBundle(
+          args.dbSessions.add(DbInboundGroupSessionBundle(
             dbSession: dbSession,
             verified: device?.verified ?? false,
           ));
@@ -1113,12 +1113,12 @@ RoomKeys generateUploadKeysImplementation(GenerateUploadKeysArgs args) {
   }
 }
 
-class _DbInboundGroupSessionBundle {
-  _DbInboundGroupSessionBundle(
+class DbInboundGroupSessionBundle {
+  DbInboundGroupSessionBundle(
       {required this.dbSession, required this.verified});
 
-  factory _DbInboundGroupSessionBundle.fromJson(Map<dynamic, dynamic> json) =>
-      _DbInboundGroupSessionBundle(
+  factory DbInboundGroupSessionBundle.fromJson(Map<dynamic, dynamic> json) =>
+      DbInboundGroupSessionBundle(
         dbSession:
             StoredInboundGroupSession.fromJson(Map.from(json['dbSession'])),
         verified: json['verified'],
@@ -1140,7 +1140,7 @@ class GenerateUploadKeysArgs {
       GenerateUploadKeysArgs(
         pubkey: json['pubkey'],
         dbSessions: (json['dbSessions'] as Iterable)
-            .map((e) => _DbInboundGroupSessionBundle.fromJson(e))
+            .map((e) => DbInboundGroupSessionBundle.fromJson(e))
             .toList(),
         userId: json['userId'],
       );
@@ -1152,6 +1152,6 @@ class GenerateUploadKeysArgs {
       };
 
   String pubkey;
-  List<_DbInboundGroupSessionBundle> dbSessions;
+  List<DbInboundGroupSessionBundle> dbSessions;
   String userId;
 }
diff --git a/lib/encryption/ssss.dart b/lib/encryption/ssss.dart
index b8828d2c..1a4b5732 100644
--- a/lib/encryption/ssss.dart
+++ b/lib/encryption/ssss.dart
@@ -68,7 +68,7 @@ class SSSS {
     _cache.clear();
   }
 
-  static _DerivedKeys deriveKeys(Uint8List key, String name) {
+  static DerivedKeys deriveKeys(Uint8List key, String name) {
     final zerosalt = Uint8List(8);
     final prk = Hmac(sha256, zerosalt).convert(key);
     final b = Uint8List(1);
@@ -77,12 +77,13 @@ class SSSS {
     b[0] = 2;
     final hmacKey =
         Hmac(sha256, prk.bytes).convert(aesKey.bytes + utf8.encode(name) + b);
-    return _DerivedKeys(
+    return DerivedKeys(
         aesKey: Uint8List.fromList(aesKey.bytes),
         hmacKey: Uint8List.fromList(hmacKey.bytes));
   }
 
-  static Future<_Encrypted> encryptAes(String data, Uint8List key, String name,
+  static Future<EncryptedContent> encryptAes(
+      String data, Uint8List key, String name,
       [String? ivStr]) async {
     Uint8List iv;
     if (ivStr != null) {
@@ -100,14 +101,14 @@ class SSSS {
 
     final hmac = Hmac(sha256, keys.hmacKey).convert(ciphertext);
 
-    return _Encrypted(
+    return EncryptedContent(
         iv: base64.encode(iv),
         ciphertext: base64.encode(ciphertext),
         mac: base64.encode(hmac.bytes));
   }
 
   static Future<String> decryptAes(
-      _Encrypted data, Uint8List key, String name) async {
+      EncryptedContent data, Uint8List key, String name) async {
     final keys = deriveKeys(key, name);
     final cipher = base64decodeUnpadded(data.ciphertext);
     final hmac = base64
@@ -318,7 +319,7 @@ class SSSS {
       throw Exception('Wrong / unknown key');
     }
     final enc = secretInfo.content['encrypted'][keyId];
-    final encryptInfo = _Encrypted(
+    final encryptInfo = EncryptedContent(
         iv: enc['iv'], ciphertext: enc['ciphertext'], mac: enc['mac']);
     final decrypted = await decryptAes(encryptInfo, key, type);
     final db = client.database;
@@ -604,19 +605,20 @@ class _ShareRequest {
       : start = DateTime.now();
 }
 
-class _Encrypted {
+class EncryptedContent {
   final String iv;
   final String ciphertext;
   final String mac;
 
-  _Encrypted({required this.iv, required this.ciphertext, required this.mac});
+  EncryptedContent(
+      {required this.iv, required this.ciphertext, required this.mac});
 }
 
-class _DerivedKeys {
+class DerivedKeys {
   final Uint8List aesKey;
   final Uint8List hmacKey;
 
-  _DerivedKeys({required this.aesKey, required this.hmacKey});
+  DerivedKeys({required this.aesKey, required this.hmacKey});
 }
 
 class OpenSSSS {