wpa_supplicant is a free software implementation of an IEEE 802.11i supplicant for Linux, BSD and Microsoft Windows. In addition to being a full-featured WPA2 supplicant, it also has support for WPA and older wireless LAN security protocols. Supported features include:
Included with the supplicant are a graphical user interface and a command line interface utility for interacting with the running supplicant. From either of these interfaces it is possible to review a list of currently visible networks, select one of them, provide any additional security information needed to authenticate with the network (e.g. a passphrase or username and password) and add it to the preference list to enable automatic reconnection in the future.