afm-main

Overview

This repository is named afm-main because it stands for AGL Framework Master - Main.

It contains programs and services to create widgets, to install widgets, to run widgets.

How to compile?

This project uses CMAKE and C compiler suite to be compiled.

Dependencies

This package requires the following libraries or modules:

• libxml-2.0
• openssl
• xmlsec1
• xmlsec1-openssl
• json-c
• dbus-1
• security-manager

This package also requires either libzip (version >= 0.11) or the binaries zip and unzip. By default, it will use libzip.

Compiling

The main scheme for compiling the project is:

cmake .

make

sudo make install

By default, the installation is made in /usr. To change this behaviour, you should set the variable CMAKE_INSTALL_PREFIX as in the below example:

cmake -DCMAKE_INSTALL_PREFIX=/some/where .

You could check the documentation of the standard CMake module GNUInstallDirs.

To forbid the use of libzip and replace it with the use of programs zip and unzip, type:

cmake -DUSE_LIBZIP=0 .

Evaluation on AGL using yocto

TO BE CONTINUED

Content

This package content source files for several programs. The installed programs are:

• afm-system-daemon: D-Bus daemon to install, uninstall, list the widgets.

It runs on the system bus.

• afm-user-daemon: D-Bus daemon to list available widgets, to start, pause, resume, stop it.

It runs on the user session bus.

• wgtpkg-info: command line tool to display information about a widget file.

• wgtpkg-install: command line tool to install a widget file.

• wgtpkg-pack: command line tool to create a widget file from a widget directory.

• wgtpkg-sign: command line tool to add a signature to a widget directory.

Description

Actors

The framework defined by afm-main is defining several actors: the platform designer, the application developer, the distributor, the user, the hacker.

The platform designer defines the AGL system and its security.

The application developer in link or not with hardware vendors is creating applications, modules, libraries, services that will be installed to the platform.

The hacker is a user that also develops application for tuning its system.

The distributor is the mediator between the developer and the user. It provides

The user is either the driver or a passenger of the car.

The application, libraries, services are available on the platform. Some of them are in direct interaction with users. Some others, like services, are used indirectly.

Scenarii

Writing applications

The application will receive an identifier. That identifier must have the following feature:

• it must be unique to identify the application and its revisions
• it should be short enough to be used with efficiency by security components of the system
• it can not be stolen by malicious applications that would like to spoof the application identity
• it can be sold to other company

The framework provide a facility to create an asymetric key that will serve all the above purposes (it currently doesn't).

Using its favorite environment, the developer produces applications for the target.

Depending on its constraints either economic, technical or human, the developer chooses the language and the environment for developing the applications.

This step needs to test and to debug the application on a target or on a simulator of the target. In both cases, the code should be lively inspected and changed, as well as the permissions and the security aspects.

The framework will provide facilities for debugging (it currently doesn't).

Packaging applications

Currently the framework expects widgets packaged as specified by Packaged Web Apps.

When the application is ready, the developer creates a package for it. The creation of the package is made of few steps:

• isolate the strict necessarily files and structure it to be children of only one root directory
• sign the application with the developer key
• sign the application with its application key
• pack the application using zip

The framework will provide facilities to package applications.

Parts of the job can be done with tools provided by afm-main:

• wgtpkg-sign is used to add signatures at root of the package
• wgtpkg-pack is used to create the package file (with wgt extension).

Currently, the config.xml file must be edited by hand. See below Writing the config.xml.

Distributing applications

Normally a store will distribute the application. It will be the normal process. The distributor adds a signature to the distributed application.

The added signature can allow more or less permission to applications. For example, a critical application nested in the system should have high level permissions allowing it to do things that should normally not be done (changing system configuration for example). To allow such application, the distributor must sign it using its secret private key that will unlock the requested level of permissions.

Currently, the framework allows to make these steps manually using unzip, wgtpkg-sign and wgtpkg-pack utilities.

Applications of the store will then be available for browsing and searching over HTTP/Internet.

Installing applications

The framework will provide an API for downloading and installing an application from stores (it currently doesn't).

The current version of afm allows to install widgets from local files (either pre-installed or downloaded).

To install a widget, you can use either the program wgtpkg-install while being the framework user.

TO BE CONTINUED

Launching application

TO BE CONTINUED

Writing the config.xml

TO BE CONTINUED

For permissions: urn:agl:perm:...

For plugins: urn:agl:plugin:...

Cryptography

The widgets are currently signed and checked using the library XMLSec.

The current state isn't providing our keys. Will be done soon.

TO BE CONTINUED

Extension to the packaging specifications

The widgets are specified in that W3C recommendation: Packaged Web Apps. This model was initially designed for HTML applications. But it is well suited for other kind of applications.

It relies on this specification that is the master piece of interest and the most useful part: XML Digital Signatures for Widgets.

An other specification exist that isn't either mature nor suited for managing privileges: Web App Manifest. However, it may become of actuallity in some future.

The main idea is to use the file config.xml as a switch for several constants. The current specifications for config.xml are allowing to describe either HTML5, QML and native applications. Using feature, it is also possible to define uses of libraries.

For more advanced uses like:

• incremental updates
• multiple application packages
• system updates

The file config.xml may:

• either, contain a root different that widget
• or, not exist, being replaced with something else.

Comparison with Tizen framework

This package is providing few less behaviour than the following Tizen packages:

• platform/appfw/app-installers
• platform/core/security/cert-svc
• platform/core/appfw/ail
• platform/core/appfw/aul-1
• platform/core/appfw/libslp-db-util
• platform/core/appfw/pkgmgr-info
• platform/core/appfw/slp-pkgmgr

Links

• Packaged Web Apps
• XML Digital Signatures for Widgets
• libxml2
• OpenSSL
• XMLSec
• JSON-c
• D-Bus
• libzip
• CMake
• Security-Manager
• Web App Manifest