<h1>Application framework</h1>
<pre><code>version: 1
-Date: 14 March 2016
+Date: 15 March 2016
Author: José Bollo
</code></pre>
<p>In case of differences, it is assumed that this document is right
and the implementation is wrong.</p>
-<a name="Introduction"></a>
-<h2>Introduction</h2>
-
-<p>During the first works in having the security model of Tizen
-integrated in AGL (Automotive Grade Linux) distribution, it became
-quickly obvious that the count of components specific to Tizen
-to integrate was huge.</p>
-
-<p>Here is a minimal list of what was needed:</p>
-
-<ul>
-<li>platform/appfw/app-installers</li>
-<li>platform/core/security/cert-svc</li>
-<li>platform/core/appfw/ail</li>
-<li>platform/core/appfw/aul-1</li>
-<li>platform/core/appfw/libslp-db-util</li>
-<li>platform/core/appfw/pkgmgr-info</li>
-<li>platform/core/appfw/slp-pkgmgr</li>
-</ul>
-
-
-<p>But this list is complete because many dependencies are hidden.
-Those hidden dependencies are including some common libraries but also many
-tizen specific sub-components (iniparser, bundle, dlog, libtzplatform-config,
-db-util, vconf-buxton, …).</p>
-
-<p>This is an issue because AGL is not expected to be Tizen. Taking it would
-either need to patch it for removing unwanted components or to take all
-of them.</p>
-
-<p>However, a careful study of the core components of the security framework
-of Tizen showed that their dependencies to Tizen are light (and since some
-of our work, there is no more dependency to tizen).
-Those components are <strong>cynara</strong>, <strong>security-manager</strong>, <strong>D-Bus aware of cynara</strong>.</p>
-
-<p>Luckyly, these core security components of Tizen are provided
-by <a href="https://github.com/01org/meta-intel-iot-security" title="A collection of layers providing security technologies">meta-intel-iot-security</a>, a set of yocto layers.
-These layers were created by Intel to isolate Tizen specific security
-components from the initial port of Tizen to Yocto.
-The 3 layers are providing components for:</p>
-
-<ul>
-<li>Implementing Smack LSM</li>
-<li>Implementing Integrity Measurement Architecture</li>
-<li>Implementing Tizen Security Framework</li>
-</ul>
-
-
-<p>The figure below shows the history of these layers.</p>
-
-<pre><code> 2014 2015
-Tizen OBS ----------+--------------------------->
- \
- \
- Tizen Yocto +---------+-------------->
- \
- \
- meta-intel-iot-security +----------->
-</code></pre>
-
-<p>We took the decision to use these security layers that provides the
-basis of the Tizen security, the security framework.</p>
-
-<p>For the components of the application framework, built top of
-the security framework, instead of pulling the huge set of packages
-from Tizen, we decided to refit it by developping a tiny set of
-components that would implement the same behaviour but without all
-the dependencies and with minor architectural improvements for AGL.</p>
-
-<p>These components are <strong>afm-system-daemon</strong> and <strong>afm-user-daemon</strong>.
-They provides infrastructure for installing, uninstalling,
-launching, terminating, stopping and resuming applications in
-a multi user secure environment.</p>
-
-<p>A third component exists in the framework, the binder <strong>afb-daemon</strong>.
-The binder provides the easiest way to provide secured API for
-any tier. Currently, the use of the binder is not absolutely mandatory.</p>
-
-<p>This documentation explains the framework created by IoT.bzh
-by rewriting the Tizen Application Framework. Be aware of the
-previous foreword.</p>
-
<a name="Overview"></a>
<h2>Overview</h2>
-<p>The figure below shows the major components of the framework
-and their interactions going through the following scenario:
-APPLICATION installs an other application and then launch it.</p>
-
-<pre><code>+-----------------------------------------------------------------------+
-| User |
-| ................................ |
-| : Smack isolation context : |
-| : : ........................... |
-| : +-----------------------+ : : Smack isolation context : |
-| : | | : : : |
-| : | APPLICATION | : : OTHER application : |
-| : | | : :.........................: |
-| : +-----------+-----------+ : ^ |
-| : | : | |
-| : |(1),(7) : |(13) |
-| : | : | |
-| : +-----------v-----------+ : +---------+---------------+ |
-| : | binder afb-daemon | : | | |
-| : +-----------------------+ : | afm-user-daemon | |
-| : | afm-main-plugin | : | | |
-| : +-----+--------------+--+ : +------^-------+------+---+ |
-| :........|..............|......: | | : |
-| |(2) |(8) |(10) | : |
-| | | | | : |
-| | +----v--------------------+---+ | : |
-| | | D-Bus session | |(11) :(12) |
-| | +-------------------------+---+ | : |
-| | | | : |
-| | |(9) | : |
-| | | | : |
-:===========|===================================|=======|======:========:
-| | | | : |
-| | +---v-------v--+ : |
-| +------v-------------+ (3) | | : |
-| | D-Bus system +-----------------> CYNARA | : |
-| +------+-------------+ | | : |
-| | +------^-------+ : |
-| |(4) | : |
-| | |(6) v |
-| +------v--------------+ +---------+---------------+ |
-| | | (5) | | |
-| | afm-system-daemon +-------------> SECURITY-MANAGER | |
-| | | | | |
-| +---------------------+ +-------------------------+ |
-| |
-| System |
-+-----------------------------------------------------------------------+
-</code></pre>
-
-<p>Let follow the sequence of calls:</p>
-
-<ol>
-<li><p>APPLICATION calls its <strong>binder</strong> to install the OTHER application.</p></li>
-<li><p>The plugin <strong>afm-main-plugin</strong> of the <strong>binder</strong> calls, through
-<strong>D-Bus</strong> system, the system daemon to install the OTHER application.</p></li>
-<li><p>The system <strong>D-Bus</strong> checks wether APPLICATION has the permission
-or not to install applications by calling <strong>CYNARA</strong>.</p></li>
-<li><p>The system <strong>D-Bus</strong> transmits the request to <strong>afm-system-daemon</strong>.</p>
-
-<p><strong>afm-system-daemon</strong> checks the application to install, its
-signatures and rights and install it.</p></li>
-<li><p><strong>afm-system-daemon</strong> calls <strong>SECURITY-MANAGER</strong> for fullfilling
-security context of the installed application.</p></li>
-<li><p><strong>SECURITY-MANAGER</strong> calls <strong>CYNARA</strong> to install initial permissions
-for the application.</p></li>
-<li><p>APPLICATION call its binder to start the nearly installed OTHER application.</p></li>
-<li><p>The plugin <strong>afm-main-plugin</strong> of the <strong>binder</strong> calls, through
-<strong>D-Bus</strong> session, the user daemon to launch the OTHER application.</p></li>
-<li><p>The session <strong>D-Bus</strong> checks wether APPLICATION has the permission
-or not to start an application by calling <strong>CYNARA</strong>.</p></li>
-<li><p>The session <strong>D-Bus</strong> transmits the request to <strong>afm-user-daemon</strong>.</p></li>
-<li><p><strong>afm-user-daemon</strong> checks wether APPLICATION has the permission
-or not to start the OTHER application <strong>CYNARA</strong>.</p></li>
-<li><p><strong>afm-user-daemon</strong> uses <strong>SECURITY-MANAGER</strong> features to set
-the seciruty context for the OTHER application.</p></li>
-<li><p><strong>afm-user-daemon</strong> launches the OTHER application.</p></li>
-</ol>
-
-
-<p>This scenario does not cover all the features of the frameworks.
-Shortly because details will be revealed in the next chapters,
-the components are:</p>
-
-<ul>
-<li><p><strong><em>SECURITY-MANAGER</em></strong>: in charge of setting Smack contexts and rules,
-of setting groups, and, of creating initial content of <em>CYNARA</em> rules
-for applications.</p></li>
-<li><p><strong><em>CYNARA</em></strong>: in charge of handling API access permissions by users and by
-applications.</p></li>
-<li><p><strong><em>D-Bus</em></strong>: in charge of checking security of messaging. The usual D-Bus
-security rules are enhanced by <em>CYNARA</em> checking rules.</p></li>
-<li><p><strong><em>afm-system-daemon</em></strong>: in charge of installing and uninstalling applications.</p></li>
-<li><p><strong><em>afm-user-daemon</em></strong>: in charge of listing applications, querying application details,
-starting, terminating, stopping, resuming applications and their instances
-for a given user context.</p></li>
-<li><p><strong><em>afb-binder</em></strong>: in charge of serving resources and features through an
-HTTP interface.</p></li>
-<li><p><strong><em>afm-main-plugin</em></strong>: This plugin allows applications to use the API
-of the AGL framework.</p></li>
-</ul>
-
-
-<a name="Links.between.the..Security.framework..and.the..Application.framework."></a>
-<h2>Links between the “Security framework” and the “Application framework”</h2>
-
-<p>The security framework refers to the security model used to ensure
-security and to the tools that are provided for implementing that model.</p>
-
-<p>The security model refers to how DAC (Discretionnary Access Control),
-MAC (Mandatory Access Control) and Capabilities are used by the system
-to ensure security and privacy. It also includes features of reporting
-using audit features and by managing logs and alerts.</p>
-
-<p>The application framework manages the applications:
-installing, uninstalling, starting, stopping, listing …</p>
-
-<p>The application framework uses the security model/framework
-to ensure the security and the privacy of the applications that
-it manages.</p>
-
-<p>The application framework must be compliant with the underlyiong
-security model/framework. But it should hide it to the applications.</p>
-
-<a name="The.security.framework"></a>
-<h2>The security framework</h2>
-
-<p>The implemented security model is the security model of Tizen 3.
-This model is described <a href="https://wiki.tizen.org/wiki/Security/Tizen_3.X_Overview" title="Tizen 3 security overview">here</a>.</p>
-
-<p>The security framework then comes from Tizen 3 but through
-the <a href="https://github.com/01org/meta-intel-iot-security" title="A collection of layers providing security technologies">meta-intel</a>.
-It includes: <strong>Security-Manager</strong>, <strong>Cynara</strong>
-and <strong>D-Bus</strong> compliant to Cynara.</p>
-
-<p>Two patches are applied to the security-manager. These patches are removing
-dependencies to packages specific of Tizen but that are not needed by AGL.
-None of these patches adds or removes any behaviour.</p>
-
-<p><strong>Theoritically, the security framework/model is an implementation details
-that should not impact the layers above the application framework</strong>.</p>
-
-<p>The security framework of Tizen provides “nice lad” a valuable component to
-scan log files and analyse auditing. This component is still in developement.</p>
-
-<a name="The.application.framework"></a>
-<h2>The application framework</h2>
-
<p>The application framework on top of the security framework
provides the components to install and uninstall applications
and to run it in a secured environment.</p>
<a name="ostro"></a>
<h3>ostro</h3>
+
+<a name="Organisation.of.directory.of.applications"></a>
+<h1>Organisation of directory of applications</h1>
+
+<p>The main path for applivcations are: APPDIR/PKGID/VER.</p>
+
+<p>Where:</p>
+
+<ul>
+<li>APPDIR is as defined above</li>
+<li>PKGID is a directory whose name is the package identifier</li>
+<li>VER is the version of the package MAJOR.MINOR</li>
+</ul>
+
+
+<p>This organisation has the advantage to allow several versions to leave together.
+This is needed for some good reasons (rolling back) and also for less good reasons (user habits).</p>
+
+<a name="Identity.of.installed.files"></a>
+<h2>Identity of installed files</h2>
+
+<p>All the files are installed as the user “userapp” and group “userapp”.
+All files have rw(x) for user and r-(x) for group and others.</p>
+
+<p>This allows any user to read the files.</p>
+
+<a name="Labelling.the.directories.of.applications"></a>
+<h2>Labelling the directories of applications</h2>
+
+<a name="Organisation.of.data"></a>
+<h1>Organisation of data</h1>
+
+<p>The data of a user are in its directory and are labelled using the labels of the application</p>
+
+<a name="Setting.Smack.rules.for.the.application"></a>
+<h1>Setting Smack rules for the application</h1>
+
+<p>For Tizen, the following rules are set by the security manager for each application.</p>
+
+<pre><code>System ~APP~ rwx
+System ~PKG~ rwxat
+System ~PKG~::RO rwxat
+~APP~ System wx
+~APP~ System::Shared rxl
+~APP~ System::Run rwxat
+~APP~ System::Log rwxa
+~APP~ _ l
+User ~APP~ rwx
+User ~PKG~ rwxat
+User ~PKG~::RO rwxat
+~APP~ User wx
+~APP~ User::Home rxl
+~APP~ User::App::Shared rwxat
+~APP~ ~PKG~ rwxat
+~APP~ ~PKG~::RO rxl
+</code></pre>
+
+<p>Here, ~PKG~ is the identifier of the package and ~APP~ is the identifier of the application.</p>
+
+<a name="What.user.can.run.an.application."></a>
+<h1>What user can run an application?</h1>
+
+<p>Not all user are able to run all applications.
+How to manage that?</p>
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Code Review / src / app-framework-main.git / blobdiff