Supplicant Architecture

Contents and Architecture

The Devicescape Supplicant operates in the user or application space of a device's operating system, performing the primary function of setting up, managing and terminating secure Wi-Fi connections.

The Devicescape Supplicant supports all Wi-Fi security mechanisms that are currently in use including WEP, dynamic WEP with 802.1X, WPA/WPA2 Pre-Shared Key (PSK), and WPA/WPA2 Enterprise. Much of the Devicescape Supplicant's internal functions concern managing the steps involved in WPA/WPA2 PSK and WPA/WPA2 Enterprise authentication. A comprehensive set of inner and outer EAP methods are supported, and it is straightforward for developers to remove code for unnecessary EAP methods, or add new EAP methods. The Devicescape Supplicant can store multiple network definitions (or preference lists) in order quickly to re-configure itself for various wireless networks. The software also supports 802.11i RSN roaming via pre-authentication.

Devicescape Supplicant Architecture

Devicescape Supplicant Architecture


For digital certificate-based EAP modes (e.g., EAP-TLS, EAP-TTLS, PEAP and optionally EAP-FAST), the Devicescape Supplicant supports an interface to external SSL/TLS libraries for certificate processing. The open source OpenSSL library is included in the product, and the Devicescape Supplicant has also been validated with small footprint commercial SSL/TLS libraries from Certicom and PeerSec Networks.

With support for the Wi-Fi Protected Setup (WPS) specification, the Devicescape Supplicant offers a simplified approach for secure network configuration at home or in a small office. Both the mandatory PIN method and the optional Pushbutton method are supported, as described in the Wi-Fi Protected Setup specification. For additional details see the Devicescape WPS webpage. Information about the Wi-Fi Protected Setup specification can be found here.

As a user-space application, the Devicescape Supplicant supports an interface to a device's network stack in order to send and receive 802.11 management and authentication frames. A driver interface is also provided to configure and read the operational state of wireless network drivers. The Devicescape Supplicant is supplied with a collection of driver wrappers that can adapt the product to various popular Wi-Fi semiconductor vendor-provided drivers from companies such as Atheros, Broadcom, Conexant, Marvell, NXP Semiconductors and TI.

Validated small footprint commercial SSL/TLS libraries

logo - peerSec Networks
logo-certicom

Two types of control interfaces are available for configuring and managing the operation of the Devicescape Supplicant: a graphical user interface (GUI) and a command line interface (CLI). Sample GUIs are available for Linux, Microsoft Windows Mobile 5.0/6.0 and Windows CE 5.0; device developers may customize these GUIs in accordance with their own product's stylistic conventions. The CLI provides developers and system administrators a deeper level of access into the operational state of the Devicescape Supplicant for debugging and troubleshooting purposes. Both the GUI and CLI use a public API that can be driven directly by external customer applications.

Devicescape delivers the Devicescape Supplicant in a base product package (with full support for WEP, 802.1X, WPA, WPA2 Personal and Enterprise, WPS), with an optional add-on module for Cisco Compatible Extensions (CCX) support. The CCX module provides for support up to version 4 of the CCX specifications, and includes features such as full enhanced EAP-FAST, CCKM, CKIP, and Cisco roaming and voice features. Customers needing the CCX module must have a signed Technology License Agreement in place with Cisco.

The Devicescape Supplicant is written in standard ANSI C, and full source code is delivered to licensed customers. This enables device software developers complete flexibility in porting the Devicescape Supplicant to the device operating system, processor, and wireless chipset of their choice. The Devicescape Supplicant has been successfully deployed on Linux, Windows XP/2000, Windows CE, Windows Mobile, Palm OS, VxWorks, ITRON, Green Hills INTEGRITY and ThreadX operating systems. The Devicescape Supplicant comes with build utilities and integration code for Linux 2.4 & 2.6, Windows Mobile 5.0 & 6.0, Windows CE 5.0 and Windows XP.

For Windows Mobile applications, the Devicescape Supplicant is supplied with an intermediate driver for the Windows Mobile NDIS stack, a sample dedicated GUI, and is architected to co-exist cleanly with the Microsoft Windows Zero Config supplicant.

The Devicescape Supplicant software product is delivered with the following: