ACC SHELL
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>History and Prior Art</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
<link rel="home" href="index.html" title="PolicyKit Library Reference Manual">
<link rel="up" href="introduction.html" title="Introduction">
<link rel="prev" href="introduction.html" title="Introduction">
<link rel="next" href="intro-define-problem.html" title="Defining the Problem">
<meta name="generator" content="GTK-Doc V1.14 (XML mode)">
<link rel="stylesheet" href="style.css" type="text/css">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2"><tr valign="middle">
<td><a accesskey="p" href="introduction.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td>
<td><a accesskey="u" href="introduction.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td>
<th width="100%" align="center">PolicyKit Library Reference Manual</th>
<td><a accesskey="n" href="intro-define-problem.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td>
</tr></table>
<div class="sect1" title="History and Prior Art">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="polkit-spec-history"></a>History and Prior Art</h2></div></div></div>
<p>
Traditionally UNIX-like operating systems have a clear
distinction between ordinary unprivileged users and the almight
and powerful super user 'root'. However, in order for a user to
access and configure hardware additional privileges and rights
are needed. Hitherto, this have been done in a number of often
OS-specific ways. For example, Red Hat based systems usually
grant access to devices to a user if, and only if, the user is
logged in at a local console. In contrast, Debian-based systems
often relies on group membership, e.g. users in the 'cdrom'
group can access optical drives, users in the 'plugdev' group
can mount removable media and so on.
</p>
<p>
In addition, access was not only granted to devices; Red
Hat-based systems, for example, provides a mechanism to allow a
user at a local system to run certain applications (such as the
system-config-* family) as the super user provided they could
authenticate as the super user (typically by entering the root
password using a graphical utility). Other distributions rely on
sudo (with various graphical frontends) to provide similar
functionality. Both the pam-console and sudo approaches doesn't
require applications to be modified.
</p>
<p>
Finally, some classes of software (such as HAL, NetworkManager
and gnome-system-tools) utilizes IPC mechanism (typically D-Bus)
to provide a very narrow and well-defined subset of privileged
operations to unprivileged desktop applications. It varies what
mechanism is used to deny users.
</p>
</div>
<div class="footer">
<hr>
Generated by GTK-Doc V1.14</div>
</body>
</html>
ACC SHELL 2018