1WPA_SUPPLICANT(8) WPA_SUPPLICANT(8)
2
6 wpa_supplicant - Wi-Fi Protected Access client and IEEE 802.1X suppli‐
7 cant
8
10 wpa_supplicant [ -BddfhKLqqsTtuvW ] [ -iifname ] [ -cconfig file ] [
11 -Ddriver ] [ -PPID_file ] [ -foutput file ]
12
14 Wireless networks do not require physical access to the network equip‐
15 ment in the same way as wired networks. This makes it easier for unau‐
16 thorized users to passively monitor a network and capture all transmit‐
17 ted frames. In addition, unauthorized use of the network is much eas‐
18 ier. In many cases, this can happen even without user's explicit knowl‐
19 edge since the wireless LAN adapter may have been configured to auto‐
20 matically join any available network.
21 Link-layer encryption can be used to provide a layer of security for
23 wireless networks. The original wireless LAN standard, IEEE 802.11,
24 included a simple encryption mechanism, WEP. However, that proved to be
25 flawed in many areas and network protected with WEP cannot be consider
26 secure. IEEE 802.1X authentication and frequently changed dynamic WEP
27 keys can be used to improve the network security, but even that has
28 inherited security issues due to the use of WEP for encryption. Wi-Fi
29 Protected Access and IEEE 802.11i amendment to the wireless LAN stan‐
30 dard introduce a much improvement mechanism for securing wireless net‐
31 works. IEEE 802.11i enabled networks that are using CCMP (encryption
32 mechanism based on strong cryptographic algorithm AES) can finally be
33 called secure used for applications which require efficient protection
34 against unauthorized access.
35 wpa_supplicant is an implementation of the WPA Supplicant component,
37 i.e., the part that runs in the client stations. It implements WPA key
38 negotiation with a WPA Authenticator and EAP authentication with
39 Authentication Server. In addition, it controls the roaming and IEEE
40 802.11 authentication/association of the wireless LAN driver.
41 wpa_supplicant is designed to be a "daemon" program that runs in the
43 background and acts as the backend component controlling the wireless
44 connection. wpa_supplicant supports separate frontend programs and an
45 example text-based frontend, wpa_cli, is included with wpa_supplicant.
46 Before wpa_supplicant can do its work, the network interface must be
48 available. That means that the physical device must be present and
49 enabled, and the driver for the device must be loaded. The daemon will
50 exit immediately if the device is not already available.
51 After wpa_supplicant has configured the network device, higher level
53 configuration such as DHCP may proceed. There are a variety of ways to
54 integrate wpa_supplicant into a machine's networking scripts, a few of
55 which are described in sections below.
56 The following steps are used when associating with an AP using WPA:
58 · wpa_supplicant requests the kernel driver to scan neighboring BSSes
60 · wpa_supplicant selects a BSS based on its configuration
62 · wpa_supplicant requests the kernel driver to associate with the cho‐
64 sen BSS
65 · If WPA-EAP: integrated IEEE 802.1X Supplicant completes EAP authenti‐
67 cation with the authentication server (proxied by the Authenticator
68 in the AP)
69 · If WPA-EAP: master key is received from the IEEE 802.1X Supplicant
71 · If WPA-PSK: wpa_supplicant uses PSK as the master session key
73 · wpa_supplicant completes WPA 4-Way Handshake and Group Key Handshake
75 with the Authenticator (AP)
76 · wpa_supplicant configures encryption keys for unicast and broadcast
78 · normal data packets can be transmitted and received
80
82 Supported WPA/IEEE 802.11i features:
83 · WPA-PSK ("WPA-Personal")
85 · WPA with EAP (e.g., with RADIUS authentication server) ("WPA-Enter‐
87 prise") Following authentication methods are supported with an inte‐
88 grate IEEE 802.1X Supplicant:
89 · EAP-TLS
91 · EAP-PEAP/MSCHAPv2 (both PEAPv0 and PEAPv1)
93 · EAP-PEAP/TLS (both PEAPv0 and PEAPv1)
95 · EAP-PEAP/GTC (both PEAPv0 and PEAPv1)
97 · EAP-PEAP/OTP (both PEAPv0 and PEAPv1)
99 · EAP-PEAP/MD5-Challenge (both PEAPv0 and PEAPv1)
101 · EAP-TTLS/EAP-MD5-Challenge
103 · EAP-TTLS/EAP-GTC
105 · EAP-TTLS/EAP-OTP
107 · EAP-TTLS/EAP-MSCHAPv2
109 · EAP-TTLS/EAP-TLS
111 · EAP-TTLS/MSCHAPv2
113 · EAP-TTLS/MSCHAP
115 · EAP-TTLS/PAP
117 · EAP-TTLS/CHAP
119 · EAP-SIM
121 · EAP-AKA
123 · EAP-PSK
125 · EAP-PAX
127 · LEAP (note: requires special support from the driver for IEEE
129 802.11 authentication)
130 · (following methods are supported, but since they do not gener‐
132 ate keying material, they cannot be used with WPA or IEEE
133 802.1X WEP keying)
134 · EAP-MD5-Challenge
136 · EAP-MSCHAPv2
138 · EAP-GTC
140 · EAP-OTP
142 · key management for CCMP, TKIP, WEP104, WEP40
144 · RSN/WPA2 (IEEE 802.11i)
146 · pre-authentication
148 · PMKSA caching
150
152 A summary of available driver backends is below. Support for each of
153 the driver backends is chosen at wpa_supplicant compile time. For a
154 list of supported driver backends that may be used with the -D option
155 on your system, refer to the help output of wpa_supplicant (wpa_suppli‐
156 cant -h).
157 nl80211
159 Uses the modern Linux nl80211/cfg80211 netlink-based interface
160 (most new drivers).
161 wext Uses the legacy Linux wireless extensions ioctl-based interface
163 (older hardware/drivers).
164 wired wpa_supplicant wired Ethernet driver
166 roboswitch
168 wpa_supplicant Broadcom switch driver
169 bsd BSD 802.11 support (Atheros, etc.).
171 ndis Windows NDIS driver.
173
175 Most command line options have global scope. Some are given per inter‐
176 face, and are only valid if at least one -i option is specified, other‐
177 wise they're ignored. Option groups for different interfaces must be
178 separated by -N option.
179 -b br_ifname
181 Optional bridge interface name. (Per interface)
182 -B Run daemon in the background.
184 -c filename
186 Path to configuration file. (Per interface)
187 -C ctrl_interface
189 Path to ctrl_interface socket (Per interface. Only used if -c is
190 not).
191 -i ifname
193 Interface to listen on. Multiple instances of this option can be
194 present, one per interface, separated by -N option (see below).
195 -d Increase debugging verbosity (-dd even more).
197 -D driver
199 Driver to use (can be multiple drivers: nl80211,wext). (Per
200 interface, see the available options below.)
201 -e entropy file
203 File for wpa_supplicant to use to maintain its internal entropy
204 store in over restarts.
205 -f output file
207 Log output to specified file instead of stdout. (This is only
208 available if wpa_supplicant was built with the CONFIG_DEBUG_FILE
209 option.)
210 -g global ctrl_interface
212 Path to global ctrl_interface socket. If specified, interface
213 definitions may be omitted.
214 -K Include keys (passwords, etc.) in debug output.
216 -h Help. Show a usage message.
218 -L Show license (BSD).
220 -o override driver
222 Override the driver parameter for new interfaces.
223 -O override ctrl_interface
225 Override the ctrl_interface parameter for new interfaces.
226 -p Driver parameters. (Per interface)
228 -P PID_file
230 Path to PID file.
231 -q Decrease debugging verbosity (-qq even less).
233 -s Log output to syslog instead of stdout. (This is only available
235 if wpa_supplicant was built with the CONFIG_DEBUG_SYSLOG
236 option.)
237 -T Log output to Linux tracing in addition to any other destina‐
239 tions. (This is only available if wpa_supplicant was built with
240 the CONFIG_DEBUG_LINUX_TRACING option.)
241 -t Include timestamp in debug messages.
243 -u Enable DBus control interface. If enabled, interface definitions
245 may be omitted. (This is only available if wpa_supplicant was
246 built with the CONFIG_CTRL_IFACE_DBUS_NEW option.)
247 -v Show version.
249 -W Wait for a control interface monitor before starting.
251 -N Start describing new interface.
253
255 In most common cases, wpa_supplicant is started with:
256 wpa_supplicant -B -c/etc/wpa_supplicant.conf -iwlan0
259 This makes the process fork into background.
263 The easiest way to debug problems, and to get debug log for bug
265 reports, is to start wpa_supplicant on foreground with debugging
266 enabled:
267 wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d
270 If the specific driver wrapper is not known beforehand, it is possible
274 to specify multiple comma separated driver wrappers on the command
275 line. wpa_supplicant will use the first driver wrapper that is able to
276 initialize the interface.
277 wpa_supplicant -Dnl80211,wext -c/etc/wpa_supplicant.conf -iwlan0
280 wpa_supplicant can control multiple interfaces (radios) either by run‐
284 ning one process for each interface separately or by running just one
285 process and list of options at command line. Each interface is sepa‐
286 rated with -N argument. As an example, following command would start
287 wpa_supplicant for two interfaces:
288 wpa_supplicant \
291 -c wpa1.conf -i wlan0 -D nl80211 -N \
292 -c wpa2.conf -i ath0 -D wext
293
297 Current hardware/software requirements:
298 · Linux kernel 2.6.30 or higher with nl80211/cfg80211 support
300 · Linux kernel 2.4.x or higher with Linux Wireless Extensions v15 or
302 newer
303 · FreeBSD 6-CURRENT
305 · Microsoft Windows with WinPcap (at least WinXP, may work with other
307 versions)
308
310 Linux nl80211/cfg80211
311 This is the preferred driver for Linux.
312 Linux wireless extensions
314 In theory, any driver that supports Linux wireless extensions
315 can be used with IEEE 802.1X (i.e., not WPA) when using
316 ap_scan=0 option in configuration file.
317 Wired Ethernet drivers
319 Use ap_scan=0.
320 BSD net80211 layer (e.g., Atheros driver)
322 At the moment, this is for FreeBSD 6-CURRENT branch.
323 Windows NDIS
325 The current Windows port requires WinPcap (http://win‐
326 pcap.polito.it/). See README-Windows.txt for more information.
327 wpa_supplicant was designed to be portable for different drivers and
329 operating systems. Hopefully, support for more wlan cards and OSes will
330 be added in the future. See developer.txt for more information about
331 the design of wpa_supplicant and porting to other drivers. One main
332 goal is to add full WPA/WPA2 support to Linux wireless extensions to
333 allow new drivers to be supported without having to implement new
334 driver-specific interface code in wpa_supplicant.
335
337 The wpa_supplicant system consists of the following components:
338 wpa_supplicant.conf
340 the configuration file describing all networks that the user
341 wants the computer to connect to.
342 wpa_supplicant
344 the program that directly interacts with the network interface.
345 wpa_cli
347 the client program that provides a high-level interface to the
348 functionality of the daemon.
349 wpa_passphrase
351 a utility needed to construct wpa_supplicant.conf files that
352 include encrypted passwords.
353
355 First, make a configuration file, e.g. /etc/wpa_supplicant.conf, that
356 describes the networks you are interested in. See wpa_suppli‐
357 cant.conf(5) for details.
358 Once the configuration is ready, you can test whether the configuration
360 works by running wpa_supplicant with following command to start it on
361 foreground with debugging enabled:
362 wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -d
365 Assuming everything goes fine, you can start using following command to
370 start wpa_supplicant on background without debugging:
371 wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -B
374 Please note that if you included more than one driver interface in the
379 build time configuration (.config), you may need to specify which
380 interface to use by including -D<driver name> option on the command
381 line.
382
384 For example, following small changes to pcmcia-cs scripts can be used
385 to enable WPA support:
386 Add MODE="Managed" and WPA="y" to the network scheme in /etc/pcm‐
388 cia/wireless.opts.
389 Add the following block to the end of start action handler in /etc/pcm‐
391 cia/wireless:
392 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
395 /usr/local/bin/wpa_supplicant -B -c/etc/wpa_supplicant.conf -i$DEVICE
396 fi
397 Add the following block to the end of stop action handler (may need to
402 be separated from other actions) in /etc/pcmcia/wireless:
403 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
406 killall wpa_supplicant
407 fi
408 This will make cardmgr start wpa_supplicant when the card is plugged
413 in.
414
416 wpa_background(8) wpa_supplicant.conf(5) wpa_cli(8) wpa_passphrase(8)
417
419 wpa_supplicant is copyright (c) 2003-2019, Jouni Malinen <j@w1.fi> and
420 contributors. All Rights Reserved.
421 This program is licensed under the BSD license (the one with advertise‐
423 ment clause removed).
424 01 March 2021 WPA_SUPPLICANT(8)