Execute actions as privileged user


KAuth provides a convenient, system-integrated way to offload actions that need to be performed as a privileged user (root, for example) to small (hopefully secure) helper utilities.


If you are using CMake, you need to have

find_package(KF6Auth NO_MODULE)

(or find KF6 with the Auth component) in your CMakeLists.txt file. You need to link to KF6::AuthCore.

Executing privileged actions typically involves having a minimal helper utility that does the actual work, and calling that utility with escalated privileges if the user has permission to do so (often requiring the user to enter appropriate credentials, like entering a password).

Therefore, use of the KAuth library is in two parts. In the main part of your code, you use KAuth::Action (and specifically KAuth::Action::execute()) when you need to do something privileged, like write to a file normally only writable by root.

The code that actually performs that action, such as writing to a file, needs to be placed in the slot of a helper QObject class, which should use the methods of KAuth::HelperSupport and be compiled into an executable. You will also want to use the kauth_install_helper_files and kauth_install_actions macros in your CMakeLists.txt.

See https://develop.kde.org/docs/features/kauth/ for a detailed tutorial on how to use KAuth.