Provided by: wpasupplicant_2.1-0ubuntu1_amd64 bug


       wpa_supplicant - Wi-Fi Protected Access client and IEEE 802.1X supplicant


       wpa_supplicant  [  -BddfhKLqqsTtuvW  ]  [  -iifname  ]  [  -cconfig  file ] [ -Ddriver ] [
       -PPID_file ] [ -foutput file ]


       Wireless networks do not require physical access to the network equipment in the same  way
       as  wired  networks.  This  makes  it easier for unauthorized users to passively monitor a
       network and capture all transmitted frames.  In addition, unauthorized use of the  network
       is  much  easier.  In  many  cases, this can happen even without user's explicit knowledge
       since the wireless LAN  adapter  may  have  been  configured  to  automatically  join  any
       available network.

       Link-layer  encryption  can  be used to provide a layer of security for wireless networks.
       The original wireless LAN standard, IEEE 802.11, included a simple  encryption  mechanism,
       WEP. However, that proved to be flawed in many areas and network protected with WEP cannot
       be consider secure. IEEE 802.1X authentication and frequently changed dynamic WEP keys can
       be  used  to improve the network security, but even that has inherited security issues due
       to the use of WEP for encryption. Wi-Fi Protected Access and IEEE 802.11i amendment to the
       wireless  LAN  standard  introduce  a  much  improvement  mechanism  for securing wireless
       networks. IEEE 802.11i enabled networks that are using CCMP (encryption mechanism based on
       strong  cryptographic  algorithm  AES)  can finally be called secure used for applications
       which require efficient protection against unauthorized access.

       wpa_supplicant is an implementation of the WPA Supplicant component, i.e., the  part  that
       runs  in  the  client stations. It implements WPA key negotiation with a WPA Authenticator
       and EAP authentication with Authentication Server. In addition, it  controls  the  roaming
       and IEEE 802.11 authentication/association of the wireless LAN driver.

       wpa_supplicant  is  designed to be a "daemon" program that runs in the background and acts
       as the backend component controlling  the  wireless  connection.  wpa_supplicant  supports
       separate  frontend  programs and an example text-based frontend, wpa_cli, is included with

       Before wpa_supplicant can do its work, the network  interface  must  be  available.   That
       means  that the physical device must be present and enabled, and the driver for the device
       must be loaded. The daemon will exit immediately if the device is not already available.

       After wpa_supplicant has configured the network device, higher level configuration such as
       DHCP  may  proceed.   There  are  a  variety  of  ways  to integrate wpa_supplicant into a
       machine's networking scripts, a few of which are described in sections below.

       The following steps are used when associating with an AP using WPA:

       • wpa_supplicant requests the kernel driver to scan neighboring BSSes

       • wpa_supplicant selects a BSS based on its configuration

       • wpa_supplicant requests the kernel driver to associate with the chosen BSS

       • If WPA-EAP: integrated IEEE 802.1X Supplicant  completes  EAP  authentication  with  the
         authentication server (proxied by the Authenticator in the AP)

       • If WPA-EAP: master key is received from the IEEE 802.1X Supplicant

       • If WPA-PSK: wpa_supplicant uses PSK as the master session key

       • wpa_supplicant   completes  WPA  4-Way  Handshake  and  Group  Key  Handshake  with  the
         Authenticator (AP)

       • wpa_supplicant configures encryption keys for unicast and broadcast

       • normal data packets can be transmitted and received


       Supported WPA/IEEE 802.11i features:

       • WPA-PSK ("WPA-Personal")

       • WPA with EAP (e.g., with  RADIUS  authentication  server)  ("WPA-Enterprise")  Following
         authentication methods are supported with an integrate IEEE 802.1X Supplicant:

         • EAP-TLS

         • EAP-PEAP/MSCHAPv2 (both PEAPv0 and PEAPv1)

         • EAP-PEAP/TLS (both PEAPv0 and PEAPv1)

         • EAP-PEAP/GTC (both PEAPv0 and PEAPv1)

         • EAP-PEAP/OTP (both PEAPv0 and PEAPv1)

         • EAP-PEAP/MD5-Challenge (both PEAPv0 and PEAPv1)

         • EAP-TTLS/EAP-MD5-Challenge

         • EAP-TTLS/EAP-GTC

         • EAP-TTLS/EAP-OTP

         • EAP-TTLS/EAP-MSCHAPv2

         • EAP-TTLS/EAP-TLS

         • EAP-TTLS/MSCHAPv2

         • EAP-TTLS/MSCHAP

         • EAP-TTLS/PAP

         • EAP-TTLS/CHAP

         • EAP-SIM

         • EAP-AKA

         • EAP-PSK

         • EAP-PAX

         • LEAP (note: requires special support from the driver for IEEE 802.11 authentication)

         • (following methods are supported, but since they do not generate keying material, they
           cannot be used with WPA or IEEE 802.1X WEP keying)

         • EAP-MD5-Challenge

         • EAP-MSCHAPv2

         • EAP-GTC

         • EAP-OTP

       • key management for CCMP, TKIP, WEP104, WEP40

       • RSN/WPA2 (IEEE 802.11i)

         • pre-authentication

         • PMKSA caching


       A summary of available driver backends is below. Support for each of the  driver  backends
       is chosen at wpa_supplicant compile time. For a list of supported driver backends that may
       be used with the -D option on your system, refer to  the  help  output  of  wpa_supplicant
       (wpa_supplicant -h).

       wext   Linux wireless extensions (generic).

       wired  wpa_supplicant wired Ethernet driver

              wpa_supplicant Broadcom switch driver

       bsd    BSD 802.11 support (Atheros, etc.).

       ndis   Windows NDIS driver.


       Most  command  line  options have global scope. Some are given per interface, and are only
       valid if at least one -i option is specified, otherwise they're ignored. Option groups for
       different interfaces must be separated by -N option.

       -b br_ifname
              Optional bridge interface name. (Per interface)

       -B     Run daemon in the background.

       -c filename
              Path to configuration file. (Per interface)

       -C ctrl_interface
              Path to ctrl_interface socket (Per interface. Only used if -c is not).

       -i ifname
              Interface  to  listen on. Multiple instances of this option can be present, one per
              interface, separated by -N option (see below).

       -d     Increase debugging verbosity (-dd even more).

       -D driver
              Driver to use (can be multiple drivers: nl80211,wext).   (Per  interface,  see  the
              available options below.)

       -e entropy file
              File  for  wpa_supplicant  to  use  to  maintain its internal entropy store in over

       -f output file
              Log output to specified  file  instead  of  stdout.  (This  is  only  available  if
              wpa_supplicant was built with the CONFIG_DEBUG_FILE option.)

       -g global ctrl_interface
              Path  to  global  ctrl_interface socket. If specified, interface definitions may be

       -K     Include keys (passwords, etc.) in debug output.

       -t     Include timestamp in debug messages.

       -h     Help.  Show a usage message.

       -L     Show license (BSD).

       -o override driver
              Override the driver parameter for new interfaces.

       -O override ctrl_interface
              Override the ctrl_interface parameter for new interfaces.

       -p     Driver parameters. (Per interface)

       -P PID_file
              Path to PID file.

       -q     Decrease debugging verbosity (-qq even less).

       -s     Log output to syslog instead of stdout. (This is only available  if  wpa_supplicant
              was built with the CONFIG_DEBUG_SYSLOG option.)

       -T     Log  output  to  Linux tracing in addition to any other destinations. (This is only
              available if wpa_supplicant was built with the CONFIG_DEBUG_LINUX_TRACING option.)

       -t     Include timestamp in debug messages.

       -u     Enable DBus control interface. If enabled, interface definitions  may  be  omitted.
              (This  is  only available if wpa_supplicant was built with the CONFIG_DBUS option.)

       -v     Show version.

       -W     Wait for a control interface monitor before starting.

       -N     Start describing new interface.


       In most common cases, wpa_supplicant is started with:

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

       This makes the process fork into background.

       The easiest way to debug problems, and to get debug log  for  bug  reports,  is  to  start
       wpa_supplicant on foreground with debugging enabled:

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

       If the specific driver wrapper is not known beforehand, it is possible to specify multiple
       comma separated driver wrappers on the command line. wpa_supplicant  will  use  the  first
       driver wrapper that is able to initialize the interface.

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

       wpa_supplicant  can control multiple interfaces (radios) either by running one process for
       each interface separately or by running just one process and list of  options  at  command
       line. Each interface is separated with -N argument. As an example, following command would
       start wpa_supplicant for two interfaces:

              wpa_supplicant \
                   -c wpa1.conf -i wlan0 -D nl80211 -N \
                   -c wpa2.conf -i ath0 -D wext


       Current hardware/software requirements:

       • Linux kernel 2.4.x or 2.6.x with Linux Wireless Extensions v15 or newer

       • FreeBSD 6-CURRENT

       • Microsoft Windows with WinPcap (at least WinXP, may work with other versions)


       Linux wireless extensions
              In theory, any driver that supports Linux wireless extensions can be used with IEEE
              802.1X (i.e., not WPA) when using ap_scan=0 option in configuration file.

       Wired Ethernet drivers
              Use ap_scan=0.

       BSD net80211 layer (e.g., Atheros driver)
              At the moment, this is for FreeBSD 6-CURRENT branch.

       Windows NDIS
              The current Windows port requires WinPcap (  See README-
              Windows.txt for more information.

       wpa_supplicant was designed to be portable for different drivers  and  operating  systems.
       Hopefully,  support  for  more  wlan  cards  and  OSes  will  be  added in the future. See
       developer.txt for more information about the design of wpa_supplicant and porting to other
       drivers.  One  main  goal  is to add full WPA/WPA2 support to Linux wireless extensions to
       allow new drivers  to  be  supported  without  having  to  implement  new  driver-specific
       interface code in wpa_supplicant.


       The wpa_supplicant system consists of the following components:

              the  configuration file describing all networks that the user wants the computer to
              connect to.

              the program that directly interacts with the network interface.

              the client program that provides a high-level interface to the functionality of the

              a  utility  needed  to  construct  wpa_supplicant.conf files that include encrypted


       First, make a configuration  file,  e.g.   /etc/wpa_supplicant.conf,  that  describes  the
       networks you are interested in.  See wpa_supplicant.conf(5) for details.

       Once  the  configuration is ready, you can test whether the configuration works by running
       wpa_supplicant with following command to start it on foreground with debugging enabled:

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

       Assuming  everything  goes  fine,  you  can  start  using  following  command   to   start
       wpa_supplicant on background without debugging:

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

       Please  note  that  if  you  included  more  than  one  driver interface in the build time
       configuration (.config), you may need to specify  which  interface  to  use  by  including
       -D<driver name> option on the command line.


       For  example,  following  small  changes  to  pcmcia-cs  scripts can be used to enable WPA

       Add MODE="Managed" and WPA="y" to the network scheme in /etc/pcmcia/wireless.opts.

       Add the following block to the end of start action handler in /etc/pcmcia/wireless:

              if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
                  /usr/local/bin/wpa_supplicant -B -c/etc/wpa_supplicant.conf -i$DEVICE

       Add the following block to the end of stop action handler (may need to be  separated  from
       other actions) in /etc/pcmcia/wireless:

              if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
                  killall wpa_supplicant

       This will make cardmgr start wpa_supplicant when the card is plugged in.


       wpa_background(8) wpa_supplicant.conf(5) wpa_cli(8) wpa_passphrase(8)


       wpa_supplicant  is copyright (c) 2003-2014, Jouni Malinen <> and contributors.  All
       Rights Reserved.

       This program is licensed  under  the  BSD  license  (the  one  with  advertisement  clause

                                          05 March 2014                         WPA_SUPPLICANT(8)