Secure Mobile Computing: Symbian Os

Features

> Browsing: full web browser support and WAP stack for mobile browsing.

> Messaging: Support SMS,MMS,EMS,POP3,IMAP4,SMTP,Standard attachment, fax.

> Multimedia: shared access to screen, keyboard, font and bitmap, audio recording, playback, image related functionality.

> Communication protocol: TCP,IP version 4, IP version 6, USB, Bluetooth.

> Mobile Telephony: abstract API for cellular system.

> Data synchronization: support USB and Bluetooth links. Transfer file and document.

> Security: full length encryption and certification management, certificate based application management.

> Most secured and customized and open source operating system.

> Support different version of mobile 2G, 2.5G, 3G.

> Integrated multimode Mobile Telephony.

> Application environment: wide range of application using C++ and Java.

> Multi tasking: Multitasking kernel to support multi tasking.

> Robustness: Data integrity and accept data from user quickly.

> Flexible user interface design. Easy to use and understand.

Development

As of 2010, the SDK for Symbian is standard C++, using Qt. It can be used with either Qt Creator, or Carbide (the older IDE previously used for Symbian development).A phone simulator allows testing of Qt apps. Apps compiled for the simulator are compiled to native code for the development platform, rather than having to be emulated.Application development can either use C++ or QML

Symbian C++

As Symbian OS is written in C++ using Symbian Software's coding standards, it is possible to develop using Symbian C++, although it is not a standard implementation. Before the release of the Qt SDK, this was the standard development environment. There were multiple platforms based on Symbian OS that provided software development kits (SDKs) for application developers wishing to target Symbian OS devices, the main ones being UIQ and S60. Individual phone products, or families, often had SDKs or SDK extensions downloadable from the maker's website too.

Other Languages

Symbian v9.1 with a S60v3 interface, on a Nokia E61

Symbian devices can also be programmed using Python, Java ME, Flash Lite, Ruby, .NET, Web Runtime (WRT)

Visual Basic programmers can use NS Basic to develop apps for S60 3rd Edition and UIQ 3 devices. In the past, Visual Basic, Visual Basic .NET, and C# development for Symbian were possible through AppForge Crossfire, a plugin for Microsoft Visual Studio. On 13 March 2007 AppForge ceased operations.

Oracle purchased the intellectual property, but announced that they did not plan to sell or provide support for former AppForge products. Net60, a .NET compact framework for Symbian, which is developed by redFIVElabs, is sold as a commercial product. With Net60, VB.NET and C# (and other) source code is compiled into an intermediate language (IL) which is executed within the Symbian OS using a just-in-time compiler. (As of Jan 18th, 2010, RedFiveLabs has ceased development of Net60 with this announcement on their landing page: "At this stage we are pursuing some options to sell the IP so that Net60 may continue to have a future.

Architecture

Technology Domains And Packages

Symbian's design is subdivided into technology domains, each of which comprises a number of software packages.

Each technology domain has its own roadmap, and the Symbian Foundation has a team of technology managers who manage these technology domain roadmaps.

Packages are owned and maintained by a package owner, a named individual from an organization member of the Symbian Foundation, who accepts code contributions from the wider Symbian community and is responsible for package.

Symbian Kernel

The Symbian kernel (EKA2) supports sufficiently fast real-time response to build a single-core phone around it – that is, a phone in which a single processor core executes both the user applications and the signalling stack.

The real-time kernel has a microkernel architecture containing only the minimum, most basic primitives and functionality, for maximum robustness, availability and responsiveness. It has been termed a nanokernel, because it needs an extended kernel to implement any other abstractions.

It contains a scheduler, memory management and device drivers, with networking, telephony and file system support services in the OS Services Layer or the Base Services Layer. The inclusion of device drivers means the kernel is not a true microkernel.

Design

Symbian OS was created with three systems design principles in mind:

The integrity and security of user data is paramount. user time must not be wasted. all resources are scarce.

To best follow these principles, Symbian uses a microkernel, has a request-and-callback approach to services, and maintains separation between user interface and engine.

The OS is optimised for low-power battery-based devices and for ROM-based systems (e.g. features like XIP and re-entrancy in shared libraries).

Applications, and the OS itself, follow an object-oriented design: Model-view-controller (MVC).

Operating System

The All over Model contains the following layers, from top to bottom:

UI Framework Layer

Application Services Layer

Java ME

OS Services Layer

Base Services Layer

Kernel Services & Hardware Interface Layer

1. Generic OS services

2. Communications services

3. Multimedia and graphics services

4. Connectivity services

Security Technology / Model

Symbian OS is subject to a variety of viruses, the best known of which is Cabir. Usually these send themselves from phone to phone by Bluetooth. Commercial developers who can afford the cost can apply to have their software signed via the Symbian Signed program. Developers also have the option of self-signing their programs. However, the set of available features does not include access to Bluetooth, IrDA, GSM CellID, voice calls, GPS and few others. Some operators opted to disable all certificates other than the Symbian Signed certificates.

Drever.A is a malicious SIS file trojan that attempts to disable the automatic startup from Simworks and Kaspersky Symbian Anti-Virus applications

Locknut.B is a malicious SIS file trojan that pretends to be a patch for Symbian S60 mobile phones. When installed, it drops a binary that will crash a critical system service component. This will prevent any application from being launched in the phone.

Mabir.A is basically Cabir with added MMS functionality. The two are written by the same author,and the code shares many similarities. It spreads using Bluetooth via the same routine as early variants of Cabir. As Mabir.A activates, it will search for the first phone it finds, and starts sending copies of itself to that phone.

Fontal.A is an SIS file trojan that installs a corrupted file which causes the phone to fail at reboot. If the user tries to reboot the infected phone, it will be permanently stick on the reboot, and cannot be used without disinfection – that is, the use of the reformat key combination which causes the phone to lose all data. Being a trojan, Frontal cannot spread by itself – the most likely way for the user to get infected would be to acquire the file from untrusted sources, and then install it to the phone, inadvertently or otherwise.

Some other hostile programs are listed below, but all of them still require the input of the user to run.

Version History