WPA supplicant

When dealing with "strong" encryption of WiFi networks, you have to setup a WPA or WPA2 configuration. To handle the requirements of these protocols during association, a userspace daemon is needed: it is called a WPA supplicant. The most used one on Linux is wpa_supplicant; we will see here how to install and configure it.

Note: wpa_supplicant is also able to handle WEP connections

Installation

$ make menuconfig

Package Selection for the target  --->
    Networking  --->
        [*]   wpa_supplicant
        [ ]     Enable WPA with EAP
        [*]     Install wpa_cli binary
        [ ]     Install wpa_passphrase binary

EAP is only needed if you plan to use WPA in Enterprise mode == with a Radius server.

Usage

wpa_supplicant needs a configuration file in /etc/wpa_supplicant.conf. Here is an example (WPA pre-shared key (TKIP)):

 ctrl_interface=/var/run/wpa_supplicant
 ctrl_interface_group=wheel
 
 network={
     ssid="''SSID''"
     scan_ssid=1
     proto=WPA
     key_mgmt=WPA-PSK
     pairwise=TKIP
     psk="''PASSPHRASE''"
 }

Then you can create the Wi-Fi connection with WPA Supplicant:

 # ifconfig wlan0 up
 # wpa_supplicant -iwlan0 -c /etc/wpa_supplicant.conf -Dwext -B dhclient

Stop it

To stop WPA Supplicant daemon and switch off the connexion, you can use this command:

 # wpa_cli terminate

Links

• wpa_supplicant README
• wpa_supplicant Webpage