=================================================
How do I get my card to use WPA-PSK in Slackware?
=================================================

First off: wpa_supplicant REQUIRES the AP to broadcast the SSID. When the AP
hides its SSID, all you will get out of wpa_supplicant is the message:
"No suitable AP found"

Also, read the MADwifi FAQ (http://madwifi.sourceforge.net/dokuwiki/doku.php)
since it contains a wealth of information.

This being said, you'll have to do the following (as root):
Edit the file named /etc/wpa_supplicant.conf and add these lines:

network={
		scan_ssid=0
		proto=WPA
		key_mgmt=WPA-PSK
		pairwise=CCMP TKIP
		group=CCMP TKIP WEP104 WEP40
}

Then execute:

/usr/sbin/wpa_passphrase YOURSSID passphrase

with the SSID of your AP and the passphrase you've entered in its WPA-PSK configuration. You'll receive an output, which looks like this:

network={
		ssid="YOURSSID"
		#psk="passphrase"

psk=66a4bfb03de5656cf26cfa03a116097546046f4aea11ee044b841171207d8308
}

Copy the three lines within the network-tag into your own entry in wpa_supplicant.conf and change the permissions after you've finished editing:

chmod 640 /etc/wpa_supplicant.conf

To get your network device up and running, execute:

### /usr/sbin/wpa_supplicant -Bw -c/etc/wpa_supplicant.conf -iath0 -Dmadwifi ###
### you don't have to run the above command by hand, because it will         ###
### be executed by the rc.inet1 command that you run:                        ###

/etc/rc.d/rc.inet1 ath0_start

In case you want to see the wpa_supplicant in action, start it on the command line before enabling the wireless device, by running:
/usr/sbin/wpa_supplicant -dw -c/etc/wpa_supplicant.conf -iath0 -Dmadwifi
The terminal where you've started the wpa_supplicant should now show the communication between your wlan card and the AP. If you got everything up and running you can let Slackware's init script take over by killing wpa_supplicant and running:

/etc/rc.d/rc.inet1 ath0_restart

Studying the wpa_supplicant README is also highly recommended for further insight!