Zirconium Linux From Scratch - Version r12.4-45-systemd

Chapter 12. Preparing Xorg and Support Libraries

Polkit-126

Introduction to Polkit

Polkit is a toolkit for defining and handling authorizations. It is used for allowing unprivileged processes to communicate with privileged processes.

This package is known to build and work properly using an LFS 12.4 platform.

Package Information

  • Download (HTTP): https://github.com/polkit-org/polkit/archive/126/polkit-126.tar.gz

  • Download SHA256 Sum: 2814a7281989f6baa9e57bd33bbc5e148827e2721ccef22aaf28ab2b376068e8

  • Download MD5 sum: db4ce0a42d5bf8002061f8e34ee9bdd0

  • Download size: 448 KB

  • Estimated disk space required: 7.4 MB (with tests)

  • Estimated build time: 0.2 SBU (with tests; using parallelism=4)

Polkit Dependencies

Required

duktape-2.7.0 and GLib-2.86.2 (GObject Introspection recommended)

Recommended

libxslt-1.1.43, Linux-PAM-1.7.1

[Note]

Note

Since systemd-logind uses PAM to register user sessions, it is a good idea to build Polkit with PAM support so systemd-logind can track Polkit sessions.

Optional

"gtk-doc" and "python-dbusmock" (required for tests)

Required Runtime Dependencies

Systemd-258.1

Optional Runtime Dependencies

One polkit authentication agent for using polkit in the graphical environment: polkit-kde-agent in "plasma-build" for KDE, the agent built in "gnome-shell" for GNOME3, "polkit-gnome" for XFCE, and "lxqt-policykit" for LXQt

[Note]

Note

If libxslt-1.1.43 is installed, then docbook-xml-4.5 and docbook-xsl-nons-1.79.2 are required. If you have installed libxslt-1.1.43, but you do not want to install any of the DocBook packages mentioned, you will need to use -D man=false in the instructions below.

Kernel Configuration

Some tests need user namespace support. If you are going to run the test suite, enable the support and recompile the kernel if necessary: 

General setup --->
  -*- Namespaces support --->                                       [NAMESPACES]
    [*] User namespace                                                 [USER_NS]

Installation of Polkit

There should be a dedicated user and group to take control of the polkitd daemon after it is started. Issue the following commands as the root user: 

groupadd -fg 27 polkitd
useradd -c "PolicyKit Daemon Owner" -d /etc/polkit-1 -u 27 \
        -g polkitd -s /bin/false polkitd

Install Polkit by running the following commands: 

meson setup build                \
      --prefix=/usr              \
      --buildtype=release        \
      -D man=true                \
      -D session_tracking=logind \
      -D tests=true

Build the package: 

ninja -C build

To test the results, first ensure that the system D-Bus daemon is running, and both "dbus-python" and "python-dbusmock" are installed. Then run: 

ninja -C build test

Now, as the root user: 

ninja -C build install

Command Explanations

--buildtype=release: Specify a buildtype suitable for stable releases of the package, as the default may produce unoptimized binaries.

-D tests=true: This switch allows to run the test suite of this package. As Polkit is used for authorizations, its integrity can affect system security. So it's recommended to run the test suite building this package.

-D os_type=lfs: Use this switch if you did not create the /etc/lfs-release file or distribution auto detection will fail and you will be unable to use Polkit.

-D authfw=shadow: This switch enables the package to use the Shadow rather than the Linux PAM Authentication framework. Use it if you have not installed Linux PAM.

-D introspection=false: Use this option if you are certain that you do not need gobject-introspection files for polkit, or do not have installed GLib-2.86.2 with GObject Introspection.

-D man=false: Use this option to disable generating and installing manual pages. This is useful if libxslt is not installed.

-D examples=true: Use this option to build the example programs.

-D gtk_doc=true: Use this option to enable building and installing the API documentation.

Contents

Installed Programs: pkaction, pkcheck, pkexec, pkttyagent, and polkitd
Installed Libraries: libpolkit-agent-1.so and libpolkit-gobject-1.so
Installed Directories: /etc/polkit-1, /usr/include/polkit-1, /usr/lib/polkit-1, /usr/share/gtk-doc/html/polkit-1, and /usr/share/polkit-1

Short Descriptions

pkaction

is used to obtain information about registered PolicyKit actions

pkcheck

is used to check whether a process is authorized for action

pkexec

allows an authorized user to execute a command as another user

pkttyagent

is used to start a textual authentication agent for the subject

polkitd

provides the org.freedesktop.PolicyKit1 D-Bus service on the system message bus

libpolkit-agent-1.so

contains the Polkit authentication agent API functions

libpolkit-gobject-1.so

contains the Polkit authorization API functions