WPA_Supplicant 介绍
wpa_supplicant 是一个WPA Supplicant工具，用于Linux，BSD，Mac OS X已经Windows系统（目前由于Windows
7的Wireless有些改动，暂时支持不是很友好）。目前支持IEEE
802.11i无线接口所定义的安全加密，WPA和WPA2。他是一个客户端工具，服务器端工具可以参考hostapd。具体详情参考官方网站。
wpa_supplicant is a WPA Supplicant for Linux, BSD, Mac OS X, and Windows with
support for WPA and WPA2 (IEEE 802.11i / RSN). It is suitable for both
desktop/laptop computers and embedded systems. Supplicant is the IEEE
802.1X/WPA component that is used in the client stations. It implements key
negotiation with a WPA Authenticator and it controls the roaming and IEEE
802.11 authentication/association of the wlan driver.
wpa_supplicant is designed to be a “daemon” program that runs in the
background and acts as the backend component controlling the wireless
connection. wpa_supplicant supports separate frontend programs and a text-
based frontend (wpa_cli) and a GUI (wpa_gui) are included with wpa_supplicant.
wpa_supplicant uses a flexible build configuration that can be used to select
which features are included. This allows minimal code size (from ca. 50 kB
binary for WPA/WPA2-Personal and 130 kB binary for WPA/WPA2-Enterprise without
debugging code to 450 kB with most features and full debugging support; these
example sizes are from a build for x86 target).