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wpa_supplicant is a wifi supplicant to handle network authentication.


As a precondition, wireless support might need to be activated in the kernel as described in Wifi/IEEE_802.11 as well as necessary wireless device drivers.[1]

USE flags

USE flags for net-wireless/wpa_supplicant IEEE 802.1X/WPA supplicant for secure wireless transfers

ap Add support for access point mode local
bindist Flag to enable or disable options for prebuilt (GRP) packages (eg. due to licensing issues) global
dbus Enable dbus support for anything that needs it (gpsd, gnomemeeting, etc) global
eap-sim Add support for EAP-SIM authentication algorithm local
eapol_test Build and install eapol_test binary local
fasteap Add support for FAST-EAP authentication algorithm local
hs2-0 Add support for 802.11u and Passpoint for HotSpot 2.0 local
p2p Add support for Wi-Fi Direct mode local
privsep Enable wpa_priv privledge separation binary local
ps3 Add support for ps3 hypervisor driven gelic wifi local
readline Enable support for libreadline, a GNU line-editing library that almost everyone wants global
smartcard Add support for smartcards local
suiteb Enable enable NSA Suite B encryption local
tdls Add support for Tunneled Direct Link Setup (802.11z) local
uncommon-eap-types Add support for GPSK, SAKE, GPSK_SHA256, IKEV2 and EKE local
wimax Add support for Wimax EAP-PEER authentication algorithm local
wps Add support for Wi-Fi Protected Setup local


After USE flags have been reviewed, install net-wireless/wpa_supplicant using Portage's emerge command:

root #emerge --ask net-wireless/wpa_supplicant



The solutions listed in Network management typically do not work together. Be sure only one of those services is running at a time. Starting more than one network management service will lead to unpredictable results!

Be sure to choose the corresponding setup.


For usage with a single wireless interface only one configuration file will be needed. This file does not exist by default; a template configuration file can be copied from /usr/share/doc/${P}/wpa_supplicant.conf.bz2 where the value of the P variable is the name and version of the currently emerged Wpa supplicant:

root #bzless /usr/share/doc/${P}/wpa_supplicant.conf.bz2 > /etc/wpa_supplicant/wpa_supplicant.conf

Next, edit the file:

FILE /etc/wpa_supplicant/wpa_supplicant.conf
# Allow users in the 'wheel' group to control wpa_supplicant
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=wheel

# Make this file writable for wpa_gui / wpa_cli

To allow unprivileged users to control the connection using wpa_gui / wpa_cli, make sure the users are in the wheel group.

Setup for dhcpcd as network manager

Emerge wpa_supplicant (Version >=2.6-r2 is needed in order to get the CONFIG_MATCH_IFACE option added in April 2017.)

root #emerge --ask net-wireless/wpa_supplicant

complete its conf.d file with the -M option

FILE /etc/conf.d/wpa_supplicant
wpa_supplicant_args="-B -M -c/etc/wpa_supplicant/wpa_supplicant.conf"

and run it as a service:

root #rc-update add wpa_supplicant default
root #/etc/init.d/wpa_supplicant start

Setup for Gentoo net.* scripts

Tell the network script to use wpa_supplicant:

FILE /etc/conf.d/net

After configuration below it is a good idea to change the permissions to ensure that WiFi passwords can not be viewed in plaintext by anyone using the computer:[2]

root #chmod 600 /etc/wpa_supplicant/wpa_supplicant.conf


Using wpa_gui

The simplest way to use wpa_supplicant is by using its interface called wpa_gui. To enable it, build wpa_supplicant with the qt5 USE flag enabled.

Using wpa_cli

Wpa_supplicant also has a command-line user interface. Typing wpa_cli starts its interactive mode with tab-completion. Typing help at this prompt will list the commands available (click "Expand" to view the output for the wpa_cli command below):

root #echo "update_config=1" >>/etc/wpa_supplicant/wpa_supplicant.conf
root #wpa_cli
wpa_cli v2.5
 Copyright (c) 2004-2015, Jouni Malinen <j@w1.fi> and contributors

 This software may be distributed under the terms of the BSD license.
 See README for more details.

 Selected interface 'wlan0'

 Interactive mode

 > scan
 > scan_results
 bssid / frequency / signal level / flags / ssid
 01:23:45:67:89:ab       2437    0       [WPA-PSK-CCMP+TKIP][WPA2-PSK-CCMP+TKIP][ESS]    hotel-free-wifi
 > add_network
 > set_network 0 ssid "hotel-free-wifi"
 > set_network 0 psk "password"
 > enable_network 0
 <3>Trying to associate with 01:23:45:67:89:ab (SSID='hotel-free-wifi' freq=2437 MHz)
 <3>Associated with 01:23:45:67:89:ab
 <3>WPA: Key negotiation completed with 01:23:45:67:89:ab [PTK=CCMP GTK=TKIP]
 <3>CTRL-EVENT-CONNECTED - Connection to 01:23:45:67:89:ab completed [id=0 id_str=]
 > save_config 
 > quit

More details on how to connect can be found in the Arch Linux wiki.[3]

Using wpa_passphrase

wpa_supplicant includes a tool to quickly write a network block from the command line for Preshared-Key (PSK aka password) networks, wpa_passphrase.

root #wpa_passphrase <ssid> [passphrase]

The SSID is required. If omitted, the passphrase can be entered when prompted.

The resulting output can then be copied or piped to /etc/wpa_supplicant/wpa_supplicant.conf.

Editing manually

Of course, the configuration file /etc/wpa_supplicant/wpa_supplicant.conf could also be edited manually. However this can be very laborious if the computer needs to connect to many different access points.

Examples can be found in man 5 wpa_supplicant.conf and /usr/share/doc/wpa_supplicant-2.4-r3/wpa_supplicant.conf.bz2.

WPA2 with wpa_supplicant

Connecting to any wireless access point serving YourSSID

FILE /etc/wpa_supplicant/wpa_supplicant.conf
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=wheel

        group=CCMP TKIP
        pairwise=CCMP TKIP

Using bssid to specify which access point it should connect to using its MAC address, in case there are repeaters in place. Remember to use wpa_passphrase <ssid> [passphrase] to generate the psk

FILE /etc/wpa_supplicant/wpa_supplicant.conf
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=wheel

        group=CCMP TKIP
        pairwise=CCMP TKIP

Auto-connect to any unsecured network

FILE /etc/wpa_supplicant/wpa_supplicant.conf


In case it does not work as expected try some of the following and analyze the output.

Check for known bugs

Run wpa_supplicant in debug mode

Be sure to stop any running instance of the supplicant:

root #killall wpa_supplicant

Something like the following options can be used for debugging (click "Expand" to view the output below):

root #wpa_supplicant -Dnl80211 -iwlan0 -C/var/run/wpa_supplicant/ -c/etc/wpa_supplicant/wpa_supplicant.conf -dd
wpa_supplicant v2.2
random: Trying to read entropy from /dev/random
Successfully initialized wpa_supplicant
Initializing interface 'wlp8s0' conf '/etc/wpa_supplicant/wpa_supplicant.conf' driver 'nl80211' ctrl_interface '/var/run/wpa_supplicant' bridge 'N/A'
Configuration file '/etc/wpa_supplicant/wpa_supplicant.conf' -> '/etc/wpa_supplicant/wpa_supplicant.conf'
Reading configuration file '/etc/wpa_supplicant/wpa_supplicant.conf'
ctrl_interface='DIR=/var/run/wpa_supplicant GROUP=wheel'
Line: 6 - start of a new network block

Enable logging


By default, wpa_supplicant performs very little debugging without the debug USE flag enabled.

root #USE="debug" emerge --ask wpa_supplicant

NOTE: As of my testing on Aug 6, 2018; debug is not a valid useflag for wpa_supplicant. You could add -dd to the wpa_supplicant_args var in /etc/conf.d/wpa_supplicant to enable debugging output. Additionally the section Enable logging for Gentoo net.* scripts has a valid way to enable debug messaging

Enable logging for Gentoo net.* scripts

FILE /etc/conf.d/netfor usage with the Setup for Gentoo net.* scripts
wpa_supplicant_wlan0="-Dnl80211 -d -f /var/log/wpa_supplicant.log"

Now, within one terminal issue a tail command to monitor output and restart the net.wlan0 device in another:

root #tail -f /var/log/wpa_supplicant.log
root #/etc/init.d/net.wlan0 restart


See also

  • iwd — an up-and-coming wireless daemon for Linux. iwd is the intended replacement for wpa_supplicant.

External resources