More or less the same:
http://blog.sudonetworks.com/2010/03/configuring-wpawpa2-on-linux-clients.html
http://ubuntuforums.org/showthread.php?t=202834&highlight=wpa+gutsy
..in a nutshell:
1. wpa_passphrase <access_point_SSID> => gives you the coded passphrase
2. Copy the coded passphrase to /etc/wpa_supplicant/wpa_supplicant.conf, like this:
(config file can be anywhere, name can be anything)
network={
ssid=”<access_point_SSID>”
#psk=<output of wpa_passphrase <access_point_SSID>>
psk=9ae7a5f631ecc688db8dcc6bbf317b4a551b39e9ee9c20effb5393e342bd954b
}
3. Enable WLAN interface with ifconfig <wlan_interface> up
+ You can search for available APs with iwlist <wlan_interface> scanning | grep -i essid
4. Configure the interface to use a specific SSID with iwconfig <wlan_interface> essid <access_point_SSID>
5. Start WPA authentication with wpa_supplicant -i<interface> -c <config_file>
6. Assign an IP with this interface or use DHCP (ddclient <interface>), set routing if necessary
You can now use your connection!