-
Notifications
You must be signed in to change notification settings - Fork 2
/
README
970 lines (778 loc) · 34.9 KB
/
README
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
WPA Supplicant
==============
Copyright (c) 2003-2008, Jouni Malinen <[email protected]> and contributors
All Rights Reserved.
This program is dual-licensed under both the GPL version 2 and BSD
license. Either license may be used at your option.
License
-------
GPL v2:
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
(this copy of the license is in COPYING file)
Alternatively, this software may be distributed, used, and modified
under the terms of BSD license:
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. Neither the name(s) of the above-listed copyright holder(s) nor the
names of its contributors may be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Features
--------
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
* EAP-SAKE
* EAP-GPSK
* 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
Supported TLS/crypto libraries:
- OpenSSL (default)
- GnuTLS
Internal TLS/crypto implementation (optional):
- can be used in place of an external TLS/crypto library
- TLSv1
- X.509 certificate processing
- PKCS #1
- ASN.1
- RSA
- bignum
- minimal size (ca. 50 kB binary, parts of which are already needed for WPA;
TLSv1/X.509/ASN.1/RSA/bignum parts are about 25 kB on x86)
Requirements
------------
Current hardware/software requirements:
- Linux kernel 2.4.x or 2.6.x with Linux Wireless Extensions v15 or newer
- FreeBSD 6-CURRENT
- NetBSD-current
- Microsoft Windows with WinPcap (at least WinXP, may work with other versions)
- drivers:
Linux drivers that support WPA/WPA2 configuration with the generic
Linux wireless extensions (WE-18 or newer). Even though there are
number of driver specific interface included in wpa_supplicant, please
note that Linux drivers are moving to use generic wireless extensions
and driver_wext (-Dwext on wpa_supplicant command line) should be the
default option to start with before falling back to driver specific
interface.
Host AP driver for Prism2/2.5/3 (development snapshot/v0.2.x)
(http://hostap.epitest.fi/)
Driver need to be set in Managed mode ('iwconfig wlan0 mode managed').
Please note that station firmware version needs to be 1.7.0 or newer
to work in WPA mode.
Linuxant DriverLoader (http://www.linuxant.com/driverloader/)
with Windows NDIS driver for your wlan card supporting WPA.
Agere Systems Inc. Linux Driver
(http://www.agere.com/support/drivers/)
Please note that the driver interface file (driver_hermes.c) and
hardware specific include files are not included in the
wpa_supplicant distribution. You will need to copy these from the
source package of the Agere driver.
madwifi driver for cards based on Atheros chip set (ar521x)
(http://sourceforge.net/projects/madwifi/)
Please note that you will need to modify the wpa_supplicant .config
file to use the correct path for the madwifi driver root directory
(CFLAGS += -I../madwifi/wpa line in example defconfig).
ATMEL AT76C5XXx driver for USB and PCMCIA cards
(http://atmelwlandriver.sourceforge.net/).
Linux ndiswrapper (http://ndiswrapper.sourceforge.net/) with
Windows NDIS driver.
Broadcom wl.o driver
This is a generic Linux driver for Broadcom IEEE 802.11a/g cards.
However, it is proprietary driver that is not publicly available
except for couple of exceptions, mainly Broadcom-based APs/wireless
routers that use Linux. The driver binary can be downloaded, e.g.,
from Linksys support site (http://www.linksys.com/support/gpl.asp)
for Linksys WRT54G. The GPL tarball includes cross-compiler and
the needed header file, wlioctl.h, for compiling wpa_supplicant.
This driver support in wpa_supplicant is expected to work also with
other devices based on Broadcom driver (assuming the driver includes
client mode support).
Intel ipw2100 driver
(http://sourceforge.net/projects/ipw2100/)
Intel ipw2200 driver
(http://sourceforge.net/projects/ipw2200/)
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 (with ap_scan=0)
BSD net80211 layer (e.g., Atheros driver)
At the moment, this is for FreeBSD 6-CURRENT branch and NetBSD-current.
Windows NDIS
The current Windows port requires WinPcap (http://winpcap.polito.it/).
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's documentation
(http://hostap.epitest.fi/wpa_supplicant/devel/) 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.
Optional libraries for layer2 packet processing:
- libpcap (tested with 0.7.2, most relatively recent versions assumed to work,
this is likely to be available with most distributions,
http://tcpdump.org/)
- libdnet (tested with v1.4, most versions assumed to work,
http://libdnet.sourceforge.net/)
These libraries are _not_ used in the default Linux build. Instead,
internal Linux specific implementation is used. libpcap/libdnet are
more portable and they can be used by adding CONFIG_L2_PACKET=pcap into
.config. They may also be selected automatically for other operating
systems. In case of Windows builds, WinPcap is used by default
(CONFIG_L2_PACKET=winpcap).
Optional libraries for EAP-TLS, EAP-PEAP, and EAP-TTLS:
- OpenSSL (tested with 0.9.7c and 0.9.7d, and 0.9.8 versions; assumed to
work with most relatively recent versions; this is likely to be
available with most distributions, http://www.openssl.org/)
- GnuTLS
- internal TLSv1 implementation
TLS options for EAP-FAST:
- OpenSSL 0.9.8d _with_ openssl-0.9.8d-tls-extensions.patch applied
(i.e., the default OpenSSL package does not include support for
extensions needed for EAP-FAST)
- internal TLSv1 implementation
One of these libraries is needed when EAP-TLS, EAP-PEAP, EAP-TTLS, or
EAP-FAST support is enabled. WPA-PSK mode does not require this or EAPOL/EAP
implementation. A configuration file, .config, for compilation is
needed to enable IEEE 802.1X/EAPOL and EAP methods. Note that EAP-MD5,
EAP-GTC, EAP-OTP, and EAP-MSCHAPV2 cannot be used alone with WPA, so
they should only be enabled if testing the EAPOL/EAP state
machines. However, there can be used as inner authentication
algorithms with EAP-PEAP and EAP-TTLS.
See Building and installing section below for more detailed
information about the wpa_supplicant build time configuration.
WPA
---
The original security mechanism of IEEE 802.11 standard was not
designed to be strong and has proven to be insufficient for most
networks that require some kind of security. Task group I (Security)
of IEEE 802.11 working group (http://www.ieee802.org/11/) has worked
to address the flaws of the base standard and has in practice
completed its work in May 2004. The IEEE 802.11i amendment to the IEEE
802.11 standard was approved in June 2004 and published in July 2004.
Wi-Fi Alliance (http://www.wi-fi.org/) used a draft version of the
IEEE 802.11i work (draft 3.0) to define a subset of the security
enhancements that can be implemented with existing wlan hardware. This
is called Wi-Fi Protected Access<TM> (WPA). This has now become a
mandatory component of interoperability testing and certification done
by Wi-Fi Alliance. Wi-Fi provides information about WPA at its web
site (http://www.wi-fi.org/OpenSection/protected_access.asp).
IEEE 802.11 standard defined wired equivalent privacy (WEP) algorithm
for protecting wireless networks. WEP uses RC4 with 40-bit keys,
24-bit initialization vector (IV), and CRC32 to protect against packet
forgery. All these choices have proven to be insufficient: key space is
too small against current attacks, RC4 key scheduling is insufficient
(beginning of the pseudorandom stream should be skipped), IV space is
too small and IV reuse makes attacks easier, there is no replay
protection, and non-keyed authentication does not protect against bit
flipping packet data.
WPA is an intermediate solution for the security issues. It uses
Temporal Key Integrity Protocol (TKIP) to replace WEP. TKIP is a
compromise on strong security and possibility to use existing
hardware. It still uses RC4 for the encryption like WEP, but with
per-packet RC4 keys. In addition, it implements replay protection,
keyed packet authentication mechanism (Michael MIC).
Keys can be managed using two different mechanisms. WPA can either use
an external authentication server (e.g., RADIUS) and EAP just like
IEEE 802.1X is using or pre-shared keys without need for additional
servers. Wi-Fi calls these "WPA-Enterprise" and "WPA-Personal",
respectively. Both mechanisms will generate a master session key for
the Authenticator (AP) and Supplicant (client station).
WPA implements a new key handshake (4-Way Handshake and Group Key
Handshake) for generating and exchanging data encryption keys between
the Authenticator and Supplicant. This handshake is also used to
verify that both Authenticator and Supplicant know the master session
key. These handshakes are identical regardless of the selected key
management mechanism (only the method for generating master session
key changes).
IEEE 802.11i / WPA2
-------------------
The design for parts of IEEE 802.11i that were not included in WPA has
finished (May 2004) and this amendment to IEEE 802.11 was approved in
June 2004. Wi-Fi Alliance is using the final IEEE 802.11i as a new
version of WPA called WPA2. This includes, e.g., support for more
robust encryption algorithm (CCMP: AES in Counter mode with CBC-MAC)
to replace TKIP and optimizations for handoff (reduced number of
messages in initial key handshake, pre-authentication, and PMKSA caching).
wpa_supplicant
--------------
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 wlan 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 wpa_supplicant.
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
Building and installing
-----------------------
In order to be able to build wpa_supplicant, you will first need to
select which parts of it will be included. This is done by creating a
build time configuration file, .config, in the wpa_supplicant root
directory. Configuration options are text lines using following
format: CONFIG_<option>=y. Lines starting with # are considered
comments and are ignored. See defconfig file for an example configuration
and a list of available options and additional notes.
The build time configuration can be used to select only the needed
features and limit the binary size and requirements for external
libraries. The main configuration parts are the selection of which
driver interfaces (e.g., hostap, madwifi, ..) and which authentication
methods (e.g., EAP-TLS, EAP-PEAP, ..) are included.
Following build time configuration options are used to control IEEE
802.1X/EAPOL and EAP state machines and all EAP methods. Including
TLS, PEAP, or TTLS will require linking wpa_supplicant with OpenSSL
library for TLS implementation. Alternatively, GnuTLS or the internal
TLSv1 implementation can be used for TLS functionaly.
CONFIG_IEEE8021X_EAPOL=y
CONFIG_EAP_MD5=y
CONFIG_EAP_MSCHAPV2=y
CONFIG_EAP_TLS=y
CONFIG_EAP_PEAP=y
CONFIG_EAP_TTLS=y
CONFIG_EAP_GTC=y
CONFIG_EAP_OTP=y
CONFIG_EAP_SIM=y
CONFIG_EAP_AKA=y
CONFIG_EAP_PSK=y
CONFIG_EAP_SAKE=y
CONFIG_EAP_GPSK=y
CONFIG_EAP_PAX=y
CONFIG_EAP_LEAP=y
Following option can be used to include GSM SIM/USIM interface for GSM/UMTS
authentication algorithm (for EAP-SIM/EAP-AKA). This requires pcsc-lite
(http://www.linuxnet.com/) for smart card access.
CONFIG_PCSC=y
Following options can be added to .config to select which driver
interfaces are included. Hermes driver interface needs to be downloaded
from Agere (see above). CONFIG_WIRELESS_EXTENSION will be used
automatically if any of the selected drivers need it.
CONFIG_WIRELESS_EXTENSION=y
CONFIG_DRIVER_HOSTAP=y
CONFIG_DRIVER_HERMES=y
CONFIG_DRIVER_MADWIFI=y
CONFIG_DRIVER_ATMEL=y
CONFIG_DRIVER_WEXT=y
CONFIG_DRIVER_NDISWRAPPER=y
CONFIG_DRIVER_BROADCOM=y
CONFIG_DRIVER_IPW=y
CONFIG_DRIVER_BSD=y
CONFIG_DRIVER_NDIS=y
Following example includes all features and driver interfaces that are
included in the wpa_supplicant package:
CONFIG_DRIVER_HOSTAP=y
CONFIG_DRIVER_HERMES=y
CONFIG_DRIVER_MADWIFI=y
CONFIG_DRIVER_ATMEL=y
CONFIG_DRIVER_WEXT=y
CONFIG_DRIVER_NDISWRAPPER=y
CONFIG_DRIVER_BROADCOM=y
CONFIG_DRIVER_IPW=y
CONFIG_DRIVER_BSD=y
CONFIG_DRIVER_NDIS=y
CONFIG_WIRELESS_EXTENSION=y
CONFIG_IEEE8021X_EAPOL=y
CONFIG_EAP_MD5=y
CONFIG_EAP_MSCHAPV2=y
CONFIG_EAP_TLS=y
CONFIG_EAP_PEAP=y
CONFIG_EAP_TTLS=y
CONFIG_EAP_GTC=y
CONFIG_EAP_OTP=y
CONFIG_EAP_SIM=y
CONFIG_EAP_AKA=y
CONFIG_EAP_PSK=y
CONFIG_EAP_SAKE=y
CONFIG_EAP_GPSK=y
CONFIG_EAP_PAX=y
CONFIG_EAP_LEAP=y
CONFIG_PCSC=y
EAP-PEAP and EAP-TTLS will automatically include configured EAP
methods (MD5, OTP, GTC, MSCHAPV2) for inner authentication selection.
After you have created a configuration file, you can build
wpa_supplicant and wpa_cli with 'make' command. You may then install
the binaries to a suitable system directory, e.g., /usr/local/bin.
Example commands:
# build wpa_supplicant and wpa_cli
make
# install binaries (this may need root privileges)
cp wpa_cli wpa_supplicant /usr/local/bin
You will need to make a configuration file, e.g.,
/etc/wpa_supplicant.conf, with network configuration for the networks
you are going to use. Configuration file section below includes
explanation fo the configuration file format and includes various
examples. Once the configuration is ready, you can test whether the
configuration work by first 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. See following section for more details on command line options
for wpa_supplicant.
Command line options
--------------------
usage:
wpa_supplicant [-BddfhKLqqtuvwW] [-P<pid file>] [-g<global ctrl>] \
-i<ifname> -c<config file> [-C<ctrl>] [-D<driver>] [-p<driver_param>] \
[-b<br_ifname> [-N -i<ifname> -c<conf> [-C<ctrl>] [-D<driver>] \
[-p<driver_param>] [-b<br_ifname>] ...]
options:
-b = optional bridge interface name
-B = run daemon in the background
-c = Configuration file
-C = ctrl_interface parameter (only used if -c is not)
-i = interface name
-d = increase debugging verbosity (-dd even more)
-D = driver name
-f = Log output to default log location (normally /tmp)
-g = global ctrl_interface
-K = include keys (passwords, etc.) in debug output
-t = include timestamp in debug messages
-h = show this help text
-L = show license (GPL and BSD)
-p = driver parameters
-P = PID file
-q = decrease debugging verbosity (-qq even less)
-v = show version
-w = wait for interface to be added, if needed
-W = wait for a control interface monitor before starting
-N = start describing new interface
drivers:
hostap = Host AP driver (Intersil Prism2/2.5/3) [default]
(this can also be used with Linuxant DriverLoader)
hermes = Agere Systems Inc. driver (Hermes-I/Hermes-II)
madwifi = MADWIFI 802.11 support (Atheros, etc.)
atmel = ATMEL AT76C5XXx (USB, PCMCIA)
wext = Linux wireless extensions (generic)
ndiswrapper = Linux ndiswrapper
broadcom = Broadcom wl.o driver
ipw = Intel ipw2100/2200 driver (old; use wext with Linux 2.6.13 or newer)
wired = wpa_supplicant wired Ethernet driver
bsd = BSD 802.11 support (Atheros, etc.)
ndis = Windows NDIS driver
In most common cases, wpa_supplicant is started with
wpa_supplicant -Bw -c/etc/wpa_supplicant.conf -iwlan0
This makes the process fork into background and wait for the wlan0
interface if it is not available at startup time.
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
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 hostap -N \
-c wpa2.conf -i ath0 -D madwifi
If the interface is added in a Linux bridge (e.g., br0), the bridge
interface needs to be configured to wpa_supplicant in addition to the
main interface:
wpa_supplicant -cw.conf -Dmadwifi -iath0 -bbr0
Configuration file
------------------
wpa_supplicant is configured using a text file that lists all accepted
networks and security policies, including pre-shared keys. See
example configuration file, wpa_supplicant.conf, for detailed
information about the configuration format and supported fields.
Changes to configuration file can be reloaded be sending SIGHUP signal
to wpa_supplicant ('killall -HUP wpa_supplicant'). Similarly,
reloading can be triggered with 'wpa_cli reconfigure' command.
Configuration file can include one or more network blocks, e.g., one
for each used SSID. wpa_supplicant will automatically select the best
betwork based on the order of network blocks in the configuration
file, network security level (WPA/WPA2 is preferred), and signal
strength.
Example configuration files for some common configurations:
1) WPA-Personal (PSK) as home network and WPA-Enterprise with EAP-TLS as work
network
# allow frontend (e.g., wpa_cli) to be used by all users in 'wheel' group
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel
#
# home network; allow all valid ciphers
network={
ssid="home"
scan_ssid=1
key_mgmt=WPA-PSK
psk="very secret passphrase"
}
#
# work network; use EAP-TLS with WPA; allow only CCMP and TKIP ciphers
network={
ssid="work"
scan_ssid=1
key_mgmt=WPA-EAP
pairwise=CCMP TKIP
group=CCMP TKIP
eap=TLS
identity="[email protected]"
ca_cert="/etc/cert/ca.pem"
client_cert="/etc/cert/user.pem"
private_key="/etc/cert/user.prv"
private_key_passwd="password"
}
2) WPA-RADIUS/EAP-PEAP/MSCHAPv2 with RADIUS servers that use old peaplabel
(e.g., Funk Odyssey and SBR, Meetinghouse Aegis, Interlink RAD-Series)
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel
network={
ssid="example"
scan_ssid=1
key_mgmt=WPA-EAP
eap=PEAP
identity="[email protected]"
password="foobar"
ca_cert="/etc/cert/ca.pem"
phase1="peaplabel=0"
phase2="auth=MSCHAPV2"
}
3) EAP-TTLS/EAP-MD5-Challenge configuration with anonymous identity for the
unencrypted use. Real identity is sent only within an encrypted TLS tunnel.
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel
network={
ssid="example"
scan_ssid=1
key_mgmt=WPA-EAP
eap=TTLS
identity="[email protected]"
anonymous_identity="[email protected]"
password="foobar"
ca_cert="/etc/cert/ca.pem"
phase2="auth=MD5"
}
4) IEEE 802.1X (i.e., no WPA) with dynamic WEP keys (require both unicast and
broadcast); use EAP-TLS for authentication
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel
network={
ssid="1x-test"
scan_ssid=1
key_mgmt=IEEE8021X
eap=TLS
identity="[email protected]"
ca_cert="/etc/cert/ca.pem"
client_cert="/etc/cert/user.pem"
private_key="/etc/cert/user.prv"
private_key_passwd="password"
eapol_flags=3
}
5) Catch all example that allows more or less all configuration modes. The
configuration options are used based on what security policy is used in the
selected SSID. This is mostly for testing and is not recommended for normal
use.
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel
network={
ssid="example"
scan_ssid=1
key_mgmt=WPA-EAP WPA-PSK IEEE8021X NONE
pairwise=CCMP TKIP
group=CCMP TKIP WEP104 WEP40
psk="very secret passphrase"
eap=TTLS PEAP TLS
identity="[email protected]"
password="foobar"
ca_cert="/etc/cert/ca.pem"
client_cert="/etc/cert/user.pem"
private_key="/etc/cert/user.prv"
private_key_passwd="password"
phase1="peaplabel=0"
ca_cert2="/etc/cert/ca2.pem"
client_cert2="/etc/cer/user.pem"
private_key2="/etc/cer/user.prv"
private_key2_passwd="password"
}
6) Authentication for wired Ethernet. This can be used with 'wired' interface
(-Dwired on command line).
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel
ap_scan=0
network={
key_mgmt=IEEE8021X
eap=MD5
identity="user"
password="password"
eapol_flags=0
}
Certificates
------------
Some EAP authentication methods require use of certificates. EAP-TLS
uses both server side and client certificates whereas EAP-PEAP and
EAP-TTLS only require the server side certificate. When client
certificate is used, a matching private key file has to also be
included in configuration. If the private key uses a passphrase, this
has to be configured in wpa_supplicant.conf ("private_key_passwd").
wpa_supplicant supports X.509 certificates in PEM and DER
formats. User certificate and private key can be included in the same
file.
If the user certificate and private key is received in PKCS#12/PFX
format, they need to be converted to suitable PEM/DER format for
wpa_supplicant. This can be done, e.g., with following commands:
# convert client certificate and private key to PEM format
openssl pkcs12 -in example.pfx -out user.pem -clcerts
# convert CA certificate (if included in PFX file) to PEM format
openssl pkcs12 -in example.pfx -out ca.pem -cacerts -nokeys
wpa_cli
-------
wpa_cli is a text-based frontend program for interacting with
wpa_supplicant. It is used to query current status, change
configuration, trigger events, and request interactive user input.
wpa_cli can show the current authentication status, selected security
mode, dot11 and dot1x MIBs, etc. In addition, it can configure some
variables like EAPOL state machine parameters and trigger events like
reassociation and IEEE 802.1X logoff/logon. wpa_cli provides a user
interface to request authentication information, like username and
password, if these are not included in the configuration. This can be
used to implement, e.g., one-time-passwords or generic token card
authentication where the authentication is based on a
challenge-response that uses an external device for generating the
response.
The control interface of wpa_supplicant can be configured to allow
non-root user access (ctrl_interface_group in the configuration
file). This makes it possible to run wpa_cli with a normal user
account.
wpa_cli supports two modes: interactive and command line. Both modes
share the same command set and the main difference is in interactive
mode providing access to unsolicited messages (event messages,
username/password requests).
Interactive mode is started when wpa_cli is executed without including
the command as a command line parameter. Commands are then entered on
the wpa_cli prompt. In command line mode, the same commands are
entered as command line arguments for wpa_cli.
Interactive authentication parameters request
When wpa_supplicant need authentication parameters, like username and
password, which are not present in the configuration file, it sends a
request message to all attached frontend programs, e.g., wpa_cli in
interactive mode. wpa_cli shows these requests with
"CTRL-REQ-<type>-<id>:<text>" prefix. <type> is IDENTITY, PASSWORD, or
OTP (one-time-password). <id> is a unique identifier for the current
network. <text> is description of the request. In case of OTP request,
it includes the challenge from the authentication server.
The reply to these requests can be given with 'identity', 'password',
and 'otp' commands. <id> needs to be copied from the the matching
request. 'password' and 'otp' commands can be used regardless of
whether the request was for PASSWORD or OTP. The main difference
between these two commands is that values given with 'password' are
remembered as long as wpa_supplicant is running whereas values given
with 'otp' are used only once and then forgotten, i.e., wpa_supplicant
will ask frontend for a new value for every use. This can be used to
implement one-time-password lists and generic token card -based
authentication.
Example request for password and a matching reply:
CTRL-REQ-PASSWORD-1:Password needed for SSID foobar
> password 1 mysecretpassword
Example request for generic token card challenge-response:
CTRL-REQ-OTP-2:Challenge 1235663 needed for SSID foobar
> otp 2 9876
wpa_cli commands
status = get current WPA/EAPOL/EAP status
mib = get MIB variables (dot1x, dot11)
help = show this usage help
interface [ifname] = show interfaces/select interface
level <debug level> = change debug level
license = show full wpa_cli license
logoff = IEEE 802.1X EAPOL state machine logoff
logon = IEEE 802.1X EAPOL state machine logon
set = set variables (shows list of variables when run without arguments)
pmksa = show PMKSA cache
reassociate = force reassociation
reconfigure = force wpa_supplicant to re-read its configuration file
preauthenticate <BSSID> = force preauthentication
identity <network id> <identity> = configure identity for an SSID
password <network id> <password> = configure password for an SSID
pin <network id> <pin> = configure pin for an SSID
otp <network id> <password> = configure one-time-password for an SSID
passphrase <network id> <passphrase> = configure private key passphrase
for an SSID
bssid <network id> <BSSID> = set preferred BSSID for an SSID
list_networks = list configured networks
select_network <network id> = select a network (disable others)
enable_network <network id> = enable a network
disable_network <network id> = disable a network
add_network = add a network
remove_network <network id> = remove a network
set_network <network id> <variable> <value> = set network variables (shows
list of variables when run without arguments)
get_network <network id> <variable> = get network variables
save_config = save the current configuration
disconnect = disconnect and wait for reassociate command before connecting
scan = request new BSS scan
scan_results = get latest scan results
get_capability <eap/pairwise/group/key_mgmt/proto/auth_alg> = get capabilies
terminate = terminate wpa_supplicant
quit = exit wpa_cli
wpa_cli command line options
wpa_cli [-p<path to ctrl sockets>] [-i<ifname>] [-hvB] [-a<action file>] \
[-P<pid file>] [-g<global ctrl>] [command..]
-h = help (show this usage text)
-v = shown version information
-a = run in daemon mode executing the action file based on events from
wpa_supplicant
-B = run a daemon in the background
default path: /var/run/wpa_supplicant
default interface: first interface found in socket path
Using wpa_cli to run external program on connect/disconnect
-----------------------------------------------------------
wpa_cli can used to run external programs whenever wpa_supplicant
connects or disconnects from a network. This can be used, e.g., to
update network configuration and/or trigget DHCP client to update IP
addresses, etc.
One wpa_cli process in "action" mode needs to be started for each
interface. For example, the following command starts wpa_cli for the
default ingterface (-i can be used to select the interface in case of
more than one interface being used at the same time):
wpa_cli -a/sbin/wpa_action.sh -B
The action file (-a option, /sbin/wpa_action.sh in this example) will
be executed whenever wpa_supplicant completes authentication (connect
event) or detects disconnection). The action script will be called
with two command line arguments: interface name and event (CONNECTED
or DISCONNECTED). If the action script needs to get more information
about the current network, it can use 'wpa_cli status' to query
wpa_supplicant for more information.
Following example can be used as a simple template for an action
script:
#!/bin/sh
IFNAME=$1
CMD=$2
if [ "$CMD" == "CONNECTED" ]; then
SSID=`wpa_cli -i$IFNAME status | grep ^ssid= | cut -f2- -d=`
# configure network, signal DHCP client, etc.
fi
if [ "$CMD" == "DISCONNECTED" ]; then
# remove network configuration, if needed
fi
Integrating with pcmcia-cs/cardmgr scripts
------------------------------------------
wpa_supplicant needs to be running when using a wireless network with
WPA. It can be started either from system startup scripts or from
pcmcia-cs/cardmgr scripts (when using PC Cards). WPA handshake must be
completed before data frames can be exchanged, so wpa_supplicant
should be started before DHCP client.
Command line option '-w' can be used if wpa_supplicant is started
before the wireless LAN interface is present (e.g., before inserting
the PC Card) or is not yet up.
For example, following small changes to pcmcia-cs scripts can be used
to enable WPA support:
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 [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
/usr/local/bin/wpa_supplicant -Bw -c/etc/wpa_supplicant.conf \
-i$DEVICE
fi
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
fi
This will make cardmgr start wpa_supplicant when the card is plugged
in. wpa_supplicant will wait until the interface is set up--either
when a static IP address is configured or when DHCP client is
started--and will then negotiate keys with the AP.
Dynamic interface add and operation without configuration files
---------------------------------------------------------------
wpa_supplicant can be started without any configuration files or
network interfaces. When used in this way, a global (i.e., per
wpa_supplicant process) control interface is used to add and remove
network interfaces. Each network interface can then be configured
through a per-network interface control interface. For example,
following commands show how to start wpa_supplicant without any
network interfaces and then add a network interface and configure a
network (SSID):
# Start wpa_supplicant in the background
wpa_supplicant -g/var/run/wpa_supplicant-global -B
# Add a new interface (wlan0, no configuration file, driver=wext, and
# enable control interface)
wpa_cli -g/var/run/wpa_supplicant-global interface_add wlan0 \
"" wext /var/run/wpa_supplicant
# Configure a network using the newly added network interface:
wpa_cli -iwlan0 add_network
wpa_cli -iwlan0 set_network 0 ssid '"test"'
wpa_cli -iwlan0 set_network 0 key_mgmt WPA-PSK
wpa_cli -iwlan0 set_network 0 psk '"12345678"'
wpa_cli -iwlan0 set_network 0 pairwise TKIP
wpa_cli -iwlan0 set_network 0 group TKIP
wpa_cli -iwlan0 set_network 0 proto WPA
wpa_cli -iwlan0 enable_network 0
# At this point, the new network interface should start trying to associate
# with the WPA-PSK network using SSID test.
# Remove network interface
wpa_cli -g/var/run/wpa_supplicant-global interface_remove wlan0