Connect to hidden Wifi AP with wpa-supplicant

command linenetworkingwifiwpa-supplicant

I have a headless Debian machine, with a Wifi dongle connected. I used to hide the Wifi AP, but now I can't.

If I unhide it, some lines in the /etc/network/interfaces will allow me to connect:

auto wlan0
iface wlan0 inet dhcp
        wpa-ssid <name>
        wpa-psk <hex/raw pwd>

If I hide the AP, add this line, then restart the interface, it won't work (DHCP gets no IP):

~~wpa-ap-scan 2~~

I've not found official documentation about the /etc/network/interfaces config.

What can I do now?

Finally, I've found out a solution, just an other line (previous not needed: ~~wpa-ap-scan~~)

wpa-scan-ssid 1

I've not really found it in any documentation... just in a forum post.

The best you can do is hash the password. Set wpa-psk to the output of:

wpa_passphrase <SSID> <KEY>

This will obfuscate the password, but it will not prevent someone else from using the hash to connect with another device.

As an additional measure you should also set /etc/network/interfaces file permission to rw------- (600), chmod og-rw.

Create a new file /etc/modprobe.d/rt2800usb.conf with the following line :

options rt2800usb nohwcrypt=1

Reboot

Or blacklist the defaut drivers and use the nl80211driver to connect through wpa_supplicant:

nano /etc/modprobe.d/blacklist.conf

add the following lines:

blacklist rt2800usb
blacklist rt2x00lib
blacklist rt2x00usb

Connect through the command line :

wpa_supplicant -Dnl80211 -iwlan0 -c/etc/wpa_supplicant.conf

If you need a GUI , Install WICD , choose your interface then go to preferences and select nl80211