1<!doctype refentry PUBLIC "-//OASIS//DTD DocBook V4.1//EN">
2
3<refentry>
4  <refmeta>
5    <refentrytitle>wpa_supplicant</refentrytitle>
6    <manvolnum>8</manvolnum>
7  </refmeta>
8  <refnamediv>
9    <refname>wpa_supplicant</refname>
10    <refpurpose>Wi-Fi Protected Access client and IEEE 802.1X supplicant</refpurpose>
11  </refnamediv>
12  <refsynopsisdiv>
13    <cmdsynopsis>
14      <command>wpa_supplicant</command>
15      <arg>-BddfhKLqqsTtuvW</arg>
16      <arg>-i<replaceable>ifname</replaceable></arg>
17      <arg>-c<replaceable>config file</replaceable></arg>
18      <arg>-D<replaceable>driver</replaceable></arg>
19      <arg>-P<replaceable>PID_file</replaceable></arg>
20      <arg>-f<replaceable>output file</replaceable></arg>
21    </cmdsynopsis>
22  </refsynopsisdiv>
23  <refsect1>
24    <title>Overview</title>
25
26    <para>
27    Wireless networks do not require physical access to the network equipment
28    in the same way as wired networks. This makes it easier for unauthorized
29    users to passively monitor a network and capture all transmitted frames.
30    In addition, unauthorized use of the network is much easier. In many cases,
31    this can happen even without user's explicit knowledge since the wireless
32    LAN adapter may have been configured to automatically join any available
33    network.
34    </para>
35
36    <para>
37    Link-layer encryption can be used to provide a layer of security for
38    wireless networks. The original wireless LAN standard, IEEE 802.11,
39    included a simple encryption mechanism, WEP. However, that proved to
40    be flawed in many areas and network protected with WEP cannot be consider
41    secure. IEEE 802.1X authentication and frequently changed dynamic WEP keys
42    can be used to improve the network security, but even that has inherited
43    security issues due to the use of WEP for encryption. Wi-Fi Protected
44    Access and IEEE 802.11i amendment to the wireless LAN standard introduce
45    a much improvement mechanism for securing wireless networks. IEEE 802.11i
46    enabled networks that are using CCMP (encryption mechanism based on strong
47    cryptographic algorithm AES) can finally be called secure used for
48    applications which require efficient protection against unauthorized
49    access.
50    </para>
51
52    <para><command>wpa_supplicant</command> is an implementation of
53    the WPA Supplicant component, i.e., the part that runs in the
54    client stations. It implements WPA key negotiation with a WPA
55    Authenticator and EAP authentication with Authentication
56    Server. In addition, it controls the roaming and IEEE 802.11
57    authentication/association of the wireless LAN driver.</para>
58
59    <para><command>wpa_supplicant</command> is designed to be a
60    "daemon" program that runs in the background and acts as the
61    backend component controlling the wireless
62    connection. <command>wpa_supplicant</command> supports separate
63    frontend programs and an example text-based frontend,
64    <command>wpa_cli</command>, is included with
65    wpa_supplicant.</para>
66
67    <para>Before wpa_supplicant can do its work, the network interface
68    must be available.  That means that the physical device must be
69    present and enabled, and the driver for the device must be
70    loaded. The daemon will exit immediately if the device is not already
71    available.</para>
72
73    <para>After <command>wpa_supplicant</command> has configured the
74    network device, higher level configuration such as DHCP may
75    proceed.  There are a variety of ways to integrate wpa_supplicant
76    into a machine's networking scripts, a few of which are described
77    in sections below.</para>
78
79    <para>The following steps are used when associating with an AP
80    using WPA:</para>
81
82    <itemizedlist>
83      <listitem>
84	<para><command>wpa_supplicant</command> requests the kernel
85	driver to scan neighboring BSSes</para>
86      </listitem>
87
88      <listitem>
89	<para><command>wpa_supplicant</command> selects a BSS based on
90	its configuration</para>
91      </listitem>
92
93      <listitem>
94	<para><command>wpa_supplicant</command> requests the kernel
95        driver to associate with the chosen BSS</para>
96      </listitem>
97
98      <listitem>
99	<para>If WPA-EAP: integrated IEEE 802.1X Supplicant
100        completes EAP authentication with the
101        authentication server (proxied by the Authenticator in the
102        AP)</para>
103      </listitem>
104
105      <listitem>
106	<para>If WPA-EAP: master key is received from the IEEE 802.1X
107	Supplicant</para>
108      </listitem>
109
110      <listitem>
111	<para>If WPA-PSK: <command>wpa_supplicant</command> uses PSK
112	as the master session key</para>
113      </listitem>
114
115      <listitem>
116	<para><command>wpa_supplicant</command> completes WPA 4-Way
117        Handshake and Group Key Handshake with the Authenticator
118        (AP)</para>
119      </listitem>
120
121      <listitem>
122	<para><command>wpa_supplicant</command> configures encryption
123	keys for unicast and broadcast</para>
124      </listitem>
125
126      <listitem>
127	<para>normal data packets can be transmitted and received</para>
128      </listitem>
129    </itemizedlist>
130  </refsect1>
131
132  <refsect1>
133    <title>Supported Features</title>
134    <para>Supported WPA/IEEE 802.11i features:</para>
135    <itemizedlist>
136      <listitem>
137	<para>WPA-PSK ("WPA-Personal")</para>
138      </listitem>
139
140      <listitem>
141	<para>WPA with EAP (e.g., with RADIUS authentication server)
142       ("WPA-Enterprise") Following authentication methods are
143       supported with an integrate IEEE 802.1X Supplicant:</para>
144
145	<itemizedlist>
146	  <listitem>
147	    <para>EAP-TLS</para>
148	  </listitem>
149	</itemizedlist>
150
151	<itemizedlist>
152	  <listitem>
153	    <para>EAP-PEAP/MSCHAPv2 (both PEAPv0 and PEAPv1)</para>
154	  </listitem>
155
156
157	  <listitem>
158	    <para>EAP-PEAP/TLS (both PEAPv0 and PEAPv1)</para>
159	  </listitem>
160
161	  <listitem>
162	    <para>EAP-PEAP/GTC (both PEAPv0 and PEAPv1)</para>
163	  </listitem>
164
165	  <listitem>
166	    <para>EAP-PEAP/OTP (both PEAPv0 and PEAPv1)</para>
167	  </listitem>
168
169	  <listitem>
170	    <para>EAP-PEAP/MD5-Challenge (both PEAPv0 and PEAPv1)</para>
171	  </listitem>
172
173	  <listitem>
174	    <para>EAP-TTLS/EAP-MD5-Challenge</para>
175	  </listitem>
176
177	  <listitem>
178	    <para>EAP-TTLS/EAP-GTC</para>
179	  </listitem>
180
181          <listitem><para>EAP-TTLS/EAP-OTP</para></listitem>
182
183          <listitem><para>EAP-TTLS/EAP-MSCHAPv2</para></listitem>
184
185          <listitem><para>EAP-TTLS/EAP-TLS</para></listitem>
186
187          <listitem><para>EAP-TTLS/MSCHAPv2</para></listitem>
188
189          <listitem><para>EAP-TTLS/MSCHAP</para></listitem>
190
191          <listitem><para>EAP-TTLS/PAP</para></listitem>
192
193          <listitem><para>EAP-TTLS/CHAP</para></listitem>
194
195          <listitem><para>EAP-SIM</para></listitem>
196
197          <listitem><para>EAP-AKA</para></listitem>
198
199          <listitem><para>EAP-PSK</para></listitem>
200
201          <listitem><para>EAP-PAX</para></listitem>
202
203          <listitem><para>LEAP (note: requires special support from
204          the driver for IEEE 802.11 authentication)</para></listitem>
205
206          <listitem><para>(following methods are supported, but since
207          they do not generate keying material, they cannot be used
208          with WPA or IEEE 802.1X WEP keying)</para></listitem>
209
210          <listitem><para>EAP-MD5-Challenge </para></listitem>
211
212          <listitem><para>EAP-MSCHAPv2</para></listitem>
213
214          <listitem><para>EAP-GTC</para></listitem>
215
216          <listitem><para>EAP-OTP</para></listitem>
217	</itemizedlist>
218      </listitem>
219
220      <listitem>
221	<para>key management for CCMP, TKIP, WEP104, WEP40</para>
222      </listitem>
223
224      <listitem>
225	<para>RSN/WPA2 (IEEE 802.11i)</para>
226	<itemizedlist>
227	  <listitem>
228	    <para>pre-authentication</para>
229	  </listitem>
230
231	  <listitem>
232	    <para>PMKSA caching</para>
233	  </listitem>
234	</itemizedlist>
235      </listitem>
236    </itemizedlist>
237  </refsect1>
238
239  <refsect1>
240    <title>Available Drivers</title>
241    <para>A summary of available driver backends is below. Support for each
242    of the driver backends is chosen at wpa_supplicant compile time. For a
243    list of supported driver backends that may be used with the -D option on
244    your system, refer to the help output of wpa_supplicant
245    (<emphasis>wpa_supplicant -h</emphasis>).</para>
246
247    <variablelist>
248      <varlistentry>
249	<term>wext</term>
250	<listitem>
251	  <para>Linux wireless extensions (generic).</para>
252	</listitem>
253      </varlistentry>
254
255      <varlistentry>
256	<term>wired</term>
257	<listitem>
258	  <para>wpa_supplicant wired Ethernet driver</para>
259	</listitem>
260      </varlistentry>
261
262      <varlistentry>
263	<term>roboswitch</term>
264	<listitem>
265	  <para>wpa_supplicant Broadcom switch driver</para>
266	</listitem>
267      </varlistentry>
268
269      <varlistentry>
270	<term>bsd</term>
271	<listitem>
272	  <para>BSD 802.11 support (Atheros, etc.).</para>
273	</listitem>
274      </varlistentry>
275
276      <varlistentry>
277	<term>ndis</term>
278	<listitem>
279	  <para>Windows NDIS driver.</para>
280	</listitem>
281      </varlistentry>
282    </variablelist>
283  </refsect1>
284
285  <refsect1>
286    <title>Command Line Options</title>
287    <para>Most command line options have global scope. Some are given per
288    interface, and are only valid if at least one <option>-i</option> option
289    is specified, otherwise they're ignored. Option groups for different
290    interfaces must be separated by <option>-N</option> option.</para>
291    <variablelist>
292      <varlistentry>
293	<term>-b br_ifname</term>
294	<listitem>
295	  <para>Optional bridge interface name. (Per interface)</para>
296	</listitem>
297      </varlistentry>
298
299      <varlistentry>
300	<term>-B</term>
301	<listitem>
302	  <para>Run daemon in the background.</para>
303	</listitem>
304      </varlistentry>
305
306      <varlistentry>
307	<term>-c filename</term>
308	<listitem>
309	  <para>Path to configuration file. (Per interface)</para>
310	</listitem>
311      </varlistentry>
312
313      <varlistentry>
314	<term>-C ctrl_interface</term>
315	<listitem>
316	  <para>Path to ctrl_interface socket (Per interface. Only used if
317		  <option>-c</option> is not).</para>
318	</listitem>
319      </varlistentry>
320
321      <varlistentry>
322	<term>-i ifname</term>
323	<listitem>
324	  <para>Interface to listen on. Multiple instances of this option can
325	  be present, one per interface, separated by <option>-N</option>
326	  option (see below).</para>
327	</listitem>
328      </varlistentry>
329
330      <varlistentry>
331	<term>-d</term>
332	<listitem>
333	  <para>Increase debugging verbosity (<option>-dd</option> even
334		  more).</para>
335	</listitem>
336      </varlistentry>
337
338      <varlistentry>
339	<term>-D driver</term>
340	<listitem>
341	  <para>Driver to use (can be multiple drivers: nl80211,wext).
342		  (Per interface, see the available options below.)</para>
343	</listitem>
344      </varlistentry>
345
346      <varlistentry>
347	<term>-e entropy file</term>
348	<listitem>
349	  <para>File for <command>wpa_supplicant</command> to use to
350	  maintain its internal entropy store in over restarts.</para>
351	</listitem>
352      </varlistentry>
353
354      <varlistentry>
355	<term>-f output file</term>
356	<listitem>
357	  <para>Log output to specified file instead of stdout. (This
358	  is only available if <command>wpa_supplicant</command> was
359	  built with the <literal>CONFIG_DEBUG_FILE</literal>
360	  option.)</para>
361	</listitem>
362      </varlistentry>
363
364      <varlistentry>
365	<term>-g global ctrl_interface</term>
366	<listitem>
367	  <para>Path to global ctrl_interface socket. If specified, interface
368	  definitions may be omitted.</para>
369	</listitem>
370      </varlistentry>
371
372      <varlistentry>
373	<term>-K</term>
374	<listitem>
375	  <para>Include keys (passwords, etc.) in debug output.</para>
376	</listitem>
377      </varlistentry>
378
379      <varlistentry>
380	<term>-h</term>
381	<listitem>
382	  <para>Help.  Show a usage message.</para>
383	</listitem>
384      </varlistentry>
385
386      <varlistentry>
387	<term>-L</term>
388	<listitem>
389	  <para>Show license (BSD).</para>
390	</listitem>
391      </varlistentry>
392
393      <varlistentry>
394	<term>-o override driver</term>
395	<listitem>
396	  <para>Override the driver parameter for new
397	  interfaces.</para>
398	</listitem>
399      </varlistentry>
400
401      <varlistentry>
402	<term>-O override ctrl_interface</term>
403	<listitem>
404	  <para>Override the ctrl_interface parameter for new
405	  interfaces.</para>
406	</listitem>
407      </varlistentry>
408
409      <varlistentry>
410	<term>-p</term>
411	<listitem>
412	  <para>Driver parameters. (Per interface)</para>
413	</listitem>
414      </varlistentry>
415
416      <varlistentry>
417	<term>-P PID_file</term>
418	<listitem>
419	  <para>Path to PID file.</para>
420	</listitem>
421      </varlistentry>
422
423      <varlistentry>
424	<term>-q</term>
425	<listitem>
426	  <para>Decrease debugging verbosity (<option>-qq</option> even
427		  less).</para>
428	</listitem>
429      </varlistentry>
430
431      <varlistentry>
432	<term>-s</term>
433	<listitem>
434	  <para>Log output to syslog instead of stdout. (This is only
435	  available if <command>wpa_supplicant</command> was built
436	  with the <literal>CONFIG_DEBUG_SYSLOG</literal>
437	  option.)</para>
438	</listitem>
439      </varlistentry>
440
441      <varlistentry>
442	<term>-T</term>
443	<listitem>
444	  <para>Log output to Linux tracing in addition to any other
445	  destinations. (This is only available
446	  if <command>wpa_supplicant</command> was built with
447	  the <literal>CONFIG_DEBUG_LINUX_TRACING</literal>
448	  option.)</para>
449	</listitem>
450      </varlistentry>
451
452      <varlistentry>
453	<term>-t</term>
454	<listitem>
455	  <para>Include timestamp in debug messages.</para>
456	</listitem>
457      </varlistentry>
458
459      <varlistentry>
460	<term>-u</term>
461	<listitem>
462	  <para>Enable DBus control interface. If enabled, interface
463	  definitions may be omitted. (This is only available
464	  if <command>wpa_supplicant</command> was built with
465	  the <literal>CONFIG_DBUS</literal> option.)</para>
466	</listitem>
467      </varlistentry>
468
469      <varlistentry>
470	<term>-v</term>
471	<listitem>
472	  <para>Show version.</para>
473	</listitem>
474      </varlistentry>
475
476      <varlistentry>
477	<term>-W</term>
478	<listitem>
479	  <para>Wait for a control interface monitor before starting.</para>
480	</listitem>
481      </varlistentry>
482
483      <varlistentry>
484	<term>-N</term>
485	<listitem>
486	  <para>Start describing new interface.</para>
487	</listitem>
488      </varlistentry>
489    </variablelist>
490  </refsect1>
491
492  <refsect1>
493    <title>Examples</title>
494
495    <para>In most common cases, <command>wpa_supplicant</command> is
496    started with:</para>
497
498<blockquote><programlisting>
499wpa_supplicant -B -c/etc/wpa_supplicant.conf -iwlan0
500</programlisting></blockquote>
501
502    <para>This makes the process fork into background.</para>
503
504    <para>The easiest way to debug problems, and to get debug log for
505    bug reports, is to start <command>wpa_supplicant</command> on
506    foreground with debugging enabled:</para>
507
508<blockquote><programlisting>
509wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d
510</programlisting></blockquote>
511
512    <para>If the specific driver wrapper is not known beforehand, it is
513    possible to specify multiple comma separated driver wrappers on the command
514    line. <command>wpa_supplicant</command> will use the first driver
515    wrapper that is able to initialize the interface.</para>
516
517<blockquote><programlisting>
518wpa_supplicant -Dnl80211,wext -c/etc/wpa_supplicant.conf -iwlan0
519</programlisting></blockquote>
520
521    <para><command>wpa_supplicant</command> can control multiple
522    interfaces (radios) either by running one process for each
523    interface separately or by running just one process and list of
524    options at command line. Each interface is separated with -N
525    argument. As an example, following command would start
526    wpa_supplicant for two interfaces:</para>
527
528<blockquote><programlisting>
529wpa_supplicant \
530	-c wpa1.conf -i wlan0 -D nl80211 -N \
531	-c wpa2.conf -i ath0 -D wext
532</programlisting></blockquote>
533  </refsect1>
534
535  <refsect1>
536    <title>OS Requirements</title>
537    <para>Current hardware/software requirements:</para>
538
539    <itemizedlist>
540      <listitem>
541	<para>Linux kernel 2.4.x or 2.6.x with Linux Wireless
542	Extensions v15 or newer</para>
543      </listitem>
544
545
546      <listitem>
547	<para>FreeBSD 6-CURRENT</para>
548      </listitem>
549
550      <listitem>
551	<para>Microsoft Windows with WinPcap (at least WinXP, may work
552	with other versions)</para>
553      </listitem>
554    </itemizedlist>
555  </refsect1>
556
557  <refsect1>
558    <title>Supported Drivers</title>
559    <variablelist>
560      <varlistentry>
561	<term>Linux wireless extensions</term>
562	<listitem>
563	  <para>In theory, any driver that supports Linux wireless
564	extensions can be used with IEEE 802.1X (i.e., not WPA) when
565	using ap_scan=0 option in configuration file.</para>
566	</listitem>
567      </varlistentry>
568
569      <varlistentry>
570	<term>Wired Ethernet drivers</term>
571	<listitem>
572	  <para>Use ap_scan=0.</para>
573	</listitem>
574      </varlistentry>
575
576      <varlistentry>
577	<term>BSD net80211 layer (e.g., Atheros driver)</term>
578	<listitem>
579	  <para>At the moment, this is for FreeBSD 6-CURRENT branch.</para>
580	</listitem>
581      </varlistentry>
582
583      <varlistentry>
584	<term>Windows NDIS</term>
585	<listitem>
586	  <para>The current Windows port requires WinPcap
587	(http://winpcap.polito.it/).  See README-Windows.txt for more
588	information.</para>
589	</listitem>
590      </varlistentry>
591    </variablelist>
592
593
594    <para>wpa_supplicant was designed to be portable for different
595    drivers and operating systems. Hopefully, support for more wlan
596    cards and OSes will be added in the future. See developer.txt for
597    more information about the design of wpa_supplicant and porting to
598    other drivers. One main goal is to add full WPA/WPA2 support to
599    Linux wireless extensions to allow new drivers to be supported
600    without having to implement new driver-specific interface code in
601    wpa_supplicant.</para>
602  </refsect1>
603
604  <refsect1>
605    <title>Architecture</title> <para>The
606    <command>wpa_supplicant</command> system consists of the following
607    components:</para>
608
609    <variablelist>
610      <varlistentry>
611	<term><filename>wpa_supplicant.conf</filename> </term>
612	<listitem>
613        <para>the configuration file describing all networks that the
614        user wants the computer to connect to.  </para>
615	</listitem>
616      </varlistentry>
617      <varlistentry>
618	<term><command>wpa_supplicant</command></term>
619        <listitem><para>the program that directly interacts with the
620        network interface.  </para></listitem>
621      </varlistentry>
622      <varlistentry>
623	<term><command>wpa_cli</command></term> <listitem><para> the
624	client program that provides a high-level interface to the
625	functionality of the daemon.  </para></listitem>
626      </varlistentry>
627      <varlistentry>
628	<term><command>wpa_passphrase</command></term>
629        <listitem><para>a utility needed to construct
630        <filename>wpa_supplicant.conf</filename> files that include
631        encrypted passwords.</para></listitem>
632      </varlistentry>
633    </variablelist>
634  </refsect1>
635
636  <refsect1>
637    <title>Quick Start</title>
638
639    <para>First, make a configuration file, e.g.
640    <filename>/etc/wpa_supplicant.conf</filename>, that describes the networks
641    you are interested in.  See <citerefentry>
642	<refentrytitle>wpa_supplicant.conf</refentrytitle>
643	<manvolnum>5</manvolnum>
644      </citerefentry>
645    for details.</para>
646
647    <para>Once the configuration is ready, you can test whether the
648    configuration works by running <command>wpa_supplicant</command>
649    with following command to start it on foreground with debugging
650    enabled:</para>
651
652    <blockquote><programlisting>
653wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -d
654    </programlisting></blockquote>
655
656    <para>Assuming everything goes fine, you can start using following
657    command to start <command>wpa_supplicant</command> on background
658    without debugging:</para>
659
660    <blockquote><programlisting>
661wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -B
662    </programlisting></blockquote>
663
664    <para>Please note that if you included more than one driver
665    interface in the build time configuration (.config), you may need
666    to specify which interface to use by including -D&lt;driver
667    name&gt; option on the command line.</para>
668
669    <!-- XXX at this point, the page could include a little script
670         based on wpa_cli to wait for a connection and then run
671         dhclient -->
672
673  </refsect1>
674
675  <refsect1>
676    <title>Interface to pcmcia-cs/cardmrg</title>
677
678    <para>For example, following small changes to pcmcia-cs scripts
679    can be used to enable WPA support:</para>
680
681    <para>Add MODE="Managed" and WPA="y" to the network scheme in
682    <filename>/etc/pcmcia/wireless.opts</filename>.</para>
683
684    <para>Add the following block to the end of <emphasis>start</emphasis>
685    action handler in <filename>/etc/pcmcia/wireless</filename>:</para>
686
687    <blockquote><programlisting>
688if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
689    /usr/local/bin/wpa_supplicant -B -c/etc/wpa_supplicant.conf -i$DEVICE
690fi
691    </programlisting></blockquote>
692
693
694    <para>Add the following block to the end of <emphasis>stop</emphasis>
695    action handler (may need to be separated from other actions) in
696    <filename>/etc/pcmcia/wireless</filename>:</para>
697
698    <blockquote><programlisting>
699if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
700    killall wpa_supplicant
701fi
702    </programlisting></blockquote>
703
704    <para>This will make <command>cardmgr</command> start
705    <command>wpa_supplicant</command> when the card is plugged
706    in.</para>
707  </refsect1>
708
709  <refsect1>
710    <title>See Also</title>
711    <para>
712      <citerefentry>
713	<refentrytitle>wpa_background</refentrytitle>
714	<manvolnum>8</manvolnum>
715      </citerefentry>
716      <citerefentry>
717	<refentrytitle>wpa_supplicant.conf</refentrytitle>
718	<manvolnum>5</manvolnum>
719      </citerefentry>
720      <citerefentry>
721	<refentrytitle>wpa_cli</refentrytitle>
722	<manvolnum>8</manvolnum>
723      </citerefentry>
724      <citerefentry>
725	<refentrytitle>wpa_passphrase</refentrytitle>
726	<manvolnum>8</manvolnum>
727      </citerefentry>
728    </para>
729  </refsect1>
730  <refsect1>
731    <title>Legal</title>
732    <para>wpa_supplicant is copyright (c) 2003-2017,
733    Jouni Malinen <email>j@w1.fi</email> and
734    contributors.
735    All Rights Reserved.</para>
736
737    <para>This program is licensed under the BSD license (the one with
738    advertisement clause removed).</para>
739  </refsect1>
740</refentry>
741