Where to store data securely from a Windows service?

Question

I'm writing a service using C# that is supposed to run on a Windows platform as the "local system". I can store small amounts of data in the registry, but if I want to store more data in a file, where do I place such file in? And also how to protect that data from a modification by users with lower access rights?

Answer 1

一般方法是使用ProtectedData类对数据进行加密，然后将它们存储在应用程序可以使用的磁盘上的任何位置（例如，在 LocalApplicationData 特殊文件夹的子文件夹中，您可以使用Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData call) 获取其位置.

Answer 2

Update to previous answer that may save some troubleshooting time to people using this solution (as I don't have enough reputation to comment):

For Local System Windows service account, Environment.SpecialFolder.LocalApplicationData may also be resolved to C:\\Windows\\SysWOW64\\config\\systemprofile\\AppData\\Local instead of C:\\Windows\\System32\\Config\\SystemProfile\\AppData\\Local .

Using the already mentioned CommonApplicationData instead of LocalApplicationData does not bring this issue.

Information source: https://www.jamescrowley.net/2014/02/24/appdata-location-when-running-under-system-user-account/