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 [ -BddehLqqvw ] [ -iifname ] [ -cconfig file ] [
11 -Ddriver ] [ -PPID_file ]
12
15 Wireless networks do not require physical access to the network equip‐
16 ment in the same way as wired networks. This makes it easier for unau‐
17 thorized users to passively monitor a network and capture all transmit‐
18 ted frames. In addition, unauthorized use of the network is much eas‐
19 ier. In many cases, this can happen even without user's explicit knowl‐
20 edge since the wireless LAN adapter may have been configured to auto‐
21 matically join any available network.
22 Link-layer encryption can be used to provide a layer of security for
24 wireless networks. The original wireless LAN standard, IEEE 802.11,
25 included a simple encryption mechanism, WEP. However, that proved to be
26 flawed in many areas and network protected with WEP cannot be consider
27 secure. IEEE 802.1X authentication and frequently changed dynamic WEP
28 keys can be used to improve the network security, but even that has
29 inherited security issues due to the use of WEP for encryption. Wi-Fi
30 Protected Access and IEEE 802.11i amendment to the wireless LAN stan‐
31 dard introduce a much improvement mechanism for securing wireless net‐
32 works. IEEE 802.11i enabled networks that are using CCMP (encryption
33 mechanism based on strong cryptographic algorithm AES) can finally be
34 called secure used for applications which require efficient protection
35 against unauthorized access.
36 wpa_supplicant is an implementation of the WPA Supplicant component,
38 i.e., the part that runs in the client stations. It implements WPA key
39 negotiation with a WPA Authenticator and EAP authentication with
40 Authentication Server. In addition, it controls the roaming and IEEE
41 802.11 authentication/association of the wireless LAN driver.
42 wpa_supplicant is designed to be a "daemon" program that runs in the
44 background and acts as the backend component controlling the wireless
45 connection. wpa_supplicant supports separate frontend programs and an
46 example text-based frontend, wpa_cli, is included with wpa_supplicant.
47 Before wpa_supplicant can do its work, the network interface must be
49 available. That means that the physical device must be present and
50 enabled, and the driver for the device must have be loaded. Note, how‐
51 ever, that the '-w' option of the wpa_supplicant daemon instructs the
52 daemon to continue running and to wait for the interface to become
53 available. Without the '-w' option, the daemon will exit immediately
54 if the device is not already available.
55 After wpa_supplicant has configured the network device, higher level
57 configuration such as DHCP may proceed. There are a variety of ways to
58 integrate wpa_supplicant into a machine's networking scripts, a few of
59 which are described in sections below.
60 The following steps are used when associating with an AP using WPA:
62 · wpa_supplicant requests the kernel driver to scan neighboring BSSes
64 · wpa_supplicant selects a BSS based on its configuration
66 · wpa_supplicant requests the kernel driver to associate with the cho‐
68 sen BSS
69 · If WPA-EAP: integrated IEEE 802.1X Supplicant or external Xsupplicant
71 completes EAP authentication with the authentication server (proxied
72 by the Authenticator in the AP)
73 · If WPA-EAP: master key is received from the IEEE 802.1X Supplicant
75 · If WPA-PSK: wpa_supplicant uses PSK as the master session key
77 · wpa_supplicant completes WPA 4-Way Handshake and Group Key Handshake
79 with the Authenticator (AP)
80 · wpa_supplicant configures encryption keys for unicast and broadcast
82 · normal data packets can be transmitted and received
84
86 Supported WPA/IEEE 802.11i features:
87 · WPA-PSK ("WPA-Personal")
89 · WPA with EAP (e.g., with RADIUS authentication server) ("WPA-Enter‐
91 prise") Following authentication methods are supported with an inte‐
92 grate IEEE 802.1X Supplicant:
93 · EAP-TLS
95 · EAP-PEAP/MSCHAPv2 (both PEAPv0 and PEAPv1)
97 · EAP-PEAP/TLS (both PEAPv0 and PEAPv1)
99 · EAP-PEAP/GTC (both PEAPv0 and PEAPv1)
101 · EAP-PEAP/OTP (both PEAPv0 and PEAPv1)
103 · EAP-PEAP/MD5-Challenge (both PEAPv0 and PEAPv1)
105 · EAP-TTLS/EAP-MD5-Challenge
107 · EAP-TTLS/EAP-GTC
109 · EAP-TTLS/EAP-OTP
111 · EAP-TTLS/EAP-MSCHAPv2
113 · EAP-TTLS/EAP-TLS
115 · EAP-TTLS/MSCHAPv2
117 · EAP-TTLS/MSCHAP
119 · EAP-TTLS/PAP
121 · EAP-TTLS/CHAP
123 · EAP-SIM
125 · EAP-AKA
127 · EAP-PSK
129 · EAP-PAX
131 · LEAP (note: requires special support from the driver for IEEE
133 802.11 authentication)
134 · (following methods are supported, but since they do not generate
136 keying material, they cannot be used with WPA or IEEE 802.1X WEP
137 keying)
138 · EAP-MD5-Challenge
140 · EAP-MSCHAPv2
142 · EAP-GTC
144 · EAP-OTP
146 · key management for CCMP, TKIP, WEP104, WEP40
148 · RSN/WPA2 (IEEE 802.11i)
150 · pre-authentication
152 · PMKSA caching
154
156 The available drivers to specify with the -D option are:
157 hostap (default) Host AP driver (Intersil Prism2/2.5/3). (this can
159 also be used with Linuxant DriverLoader).
160 hermes Agere Systems Inc. driver (Hermes-I/Hermes-II).
162 madwifi
164 MADWIFI 802.11 support (Atheros, etc.).
165 atmel ATMEL AT76C5XXx (USB, PCMCIA).
167 wext Linux wireless extensions (generic).
169 ndiswrapper
171 Linux ndiswrapper.
172 broadcom
174 Broadcom wl.o driver.
175 ipw Intel ipw2100/2200 driver.
177 wired wpa_supplicant wired Ethernet driver
179 bsd BSD 802.11 support (Atheros, etc.).
181 ndis Windows NDIS driver.
183
185 -B Run daemon in the background.
186 -i ifname
188 Interface to listen on.
189 -c filename
191 Path to configuration file.
192 -P PID_file
194 Path to PID file.
195 -C ctrl_interface
197 Path to ctrl_interface socket (only used if -c is not).
198 -g global ctrl_interface
200 Path to global ctrl_interface socket.
201 -D driver
203 Driver to use. See the available options below.
204 -d Increase debugging verbosity (-dd even more).
206 -K Include keys (passwords, etc.) in debug output.
208 -t Include timestamp in debug messages.
210 -e Use external IEEE 802.1X Supplicant (e.g., xsupplicant) (this
212 disables the internal Supplicant).
213 -h Help. Show a usage message.
215 -L Show license (GPL and BSD).
217 -q Decrease debugging verbosity (-qq even less).
219 -v Show version.
221 -w wait for interface to be added, if needed. normally, wpa_sup‐
223 plicant will exit if the interface is not there yet.
224 -N Start describing new interface.
226
228 In most common cases, wpa_supplicant is started with:
229 wpa_supplicant -Bw -c/etc/wpa_supplicant.conf -iwlan0
232 This makes the process fork into background and wait for the wlan0
234 interface if it is not available at startup time.
235 The easiest way to debug problems, and to get debug log for bug
237 reports, is to start wpa_supplicant on foreground with debugging
238 enabled:
239 wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d
242 wpa_supplicant can control multiple interfaces (radios) either by run‐
244 ning one process for each interface separately or by running just one
245 process and list of options at command line. Each interface is sepa‐
246 rated with -N argument. As an example, following command would start
247 wpa_supplicant for two interfaces:
248 wpa_supplicant \
251 -c wpa1.conf -i wlan0 -D hostap -N \
252 -c wpa2.conf -i ath0 -D madwifi
253
255 Current hardware/software requirements:
256 · Linux kernel 2.4.x or 2.6.x with Linux Wireless Extensions v15 or
258 newer
259 · FreeBSD 6-CURRENT
261 · Microsoft Windows with WinPcap (at least WinXP, may work with other
263 versions)
264
266 Host AP driver for Prism2/2.5/3 (development snapshot/v0.2.x)
267 (http://hostap.epitest.fi/) Driver needs to be set in Managed
268 mode ('iwconfig wlan0 mode managed'). Please note that station
269 firmware version needs to be 1.7.0 or newer to work in WPA mode.
270 Linuxant DriverLoader
272 (http://www.linuxant.com/driverloader/) with Windows NDIS driver
273 for your wlan card supporting WPA.
274 Agere Systems Inc. Linux Driver
276 (http://www.agere.com/support/drivers/) Please note that the
277 driver interface file (driver_hermes.c) and hardware specific
278 include files are not included in the wpa_supplicant distribu‐
279 tion. You will need to copy these from the source package of the
280 Agere driver.
281 madwifi driver for cards based on Atheros chip set (ar521x)
283 (http://sourceforge.net/projects/madwifi/) Please note that you
284 will need to modify the wpa_supplicant .config file to use the
285 correct path for the madwifi driver root directory (CFLAGS +=
286 -I../madwifi/wpa line in example defconfig).
287 ATMEL AT76C5XXx driver for USB and PCMCIA cards
289 (http://atmelwlandriver.sourceforge.net/).
290 Linux ndiswrapper
292 (http://ndiswrapper.sourceforge.net/) with Windows NDIS driver.
293 Broadcom wl.o driver
295 This is a generic Linux driver for Broadcom IEEE 802.11a/g
296 cards. However, it is proprietary driver that is not publicly
297 available except for couple of exceptions, mainly Broadcom-based
298 APs/wireless routers that use Linux. The driver binary can be
299 downloaded, e.g., from Linksys support site
300 (http://www.linksys.com/support/gpl.asp) for Linksys WRT54G. The
301 GPL tarball includes cross-compiler and the needed header file,
302 wlioctl.h, for compiling wpa_supplicant. This driver support in
303 wpa_supplicant is expected to work also with other devices based
304 on Broadcom driver (assuming the driver includes client mode
305 support).
306 Intel ipw2100 driver
308 (http://sourceforge.net/projects/ipw2100/)
309 Intel ipw2200 driver
311 (http://sourceforge.net/projects/ipw2200/)
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
368 start wpa_supplicant on background without debugging:
369 wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -B
372 Please note that if you included more than one driver interface in the
375 build time configuration (.config), you may need to specify which
376 interface to use by including -D<driver name> option on the command
377 line.
378
380 For example, following small changes to pcmcia-cs scripts can be used
381 to enable WPA support:
382 Add MODE="Managed" and WPA="y" to the network scheme in /etc/pcm‐
384 cia/wireless.opts.
385 Add the following block to the end of 'start' action handler in
387 /etc/pcmcia/wireless:
388 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
391 /usr/local/bin/wpa_supplicant -Bw -c/etc/wpa_supplicant.conf -i$DEVICE
392 fi
393 Add the following block to the end of 'stop' action handler (may need
396 to be separated from other actions) in /etc/pcmcia/wireless:
397 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
400 killall wpa_supplicant
401 fi
402 This will make cardmgr start wpa_supplicant when the card is plugged
405 in. wpa_supplicant will wait until the interface is set up--either when
406 a static IP address is configured or when DHCP client is started--and
407 will then negotiate keys with the AP.
408
410 wpa_background(8) wpa_supplicant.conf(5) wpa_cli(8) wpa_passphrase(8)
411
413 wpa_supplicant is copyright (c) 2003-2005, Jouni Malinen <jkma‐
414 line@cc.hut.fi> and contributors. All Rights Reserved.
415 This program is dual-licensed under both the GPL version 2 and BSD
417 license. Either license may be used at your option.
418 31 December 2006 WPA_SUPPLICANT(8)