Reject oversized keys in Apple decoders

Core/CodedInputDataCrypt_OSX.cpp

@@ -43,6 +43,9 @@ NSString *CodedInputDataCrypt::readNSString(KeyValueHolderCrypt &kvHolder) {
 
     auto s_size = static_cast<size_t>(size);
     if (s_size <= m_size - m_position) {
+        if (s_size > mmkv::KeySizeLimit) {
+            throw length_error("MMKV key too large for uint16 holder");
+        }
         consumeBytes(s_size);
 
         kvHolder.keySize = static_cast<uint16_t>(s_size);