Saturday, 25 February 2012

How to run an application under active session account from a Windows service using Delphi

To run an application from a service impersonating an user account, first we need to install "JEDI API Library & Security Code Library" as it contains different interesting OS callings which are really useful in order to achieve our purposes. Once the library has been unzipped, create your own service where the library is located and add the following paths to your search path in your project options:

Then instead of using CreateProcess function to execute an application, we need to use CreateProcessAsUser function. The new process runs in the security context of the user represented by the specified token. The service must be run by the  LocalSystem account which is a predefined local account used by the service control manager. To be able to use the function from jedi-apilib which retrieves the token from the current user we need to use WTSQueryUserToken ( WtsGetActiveConsoleSessionID, hToken ) function. This function will only work under LocalSystem account which has SE_TCB_NAME property enabled, otherwise the query will be false.

Use the following example within your service:



Related links:

4 comments:

  1. Wrote about that while ago. Also with example project:

    http://www.cromis.net/blog/2010/01/how-to-start-a-gui-process-from-service-under-windows-vista7/

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    Replies
    1. Thanks for letting me know. It is actually a very good article.

      Delete
  2. Thanks very much for this example. This is the only working version in delphi i have found.

    Much less code and still working fine. Thanks again for share this code.

    ReplyDelete