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>-BddfhKLqqtuvW</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>-f output file</term> 348 <listitem> 349 <para>Log output to specified file instead of stdout.</para> 350 </listitem> 351 </varlistentry> 352 353 <varlistentry> 354 <term>-g global ctrl_interface</term> 355 <listitem> 356 <para>Path to global ctrl_interface socket. If specified, interface 357 definitions may be omitted.</para> 358 </listitem> 359 </varlistentry> 360 361 <varlistentry> 362 <term>-K</term> 363 <listitem> 364 <para>Include keys (passwords, etc.) in debug output.</para> 365 </listitem> 366 </varlistentry> 367 368 <varlistentry> 369 <term>-t</term> 370 <listitem> 371 <para>Include timestamp in debug messages.</para> 372 </listitem> 373 </varlistentry> 374 375 <varlistentry> 376 <term>-h</term> 377 <listitem> 378 <para>Help. Show a usage message.</para> 379 </listitem> 380 </varlistentry> 381 382 <varlistentry> 383 <term>-L</term> 384 <listitem> 385 <para>Show license (BSD).</para> 386 </listitem> 387 </varlistentry> 388 389 <varlistentry> 390 <term>-p</term> 391 <listitem> 392 <para>Driver parameters. (Per interface)</para> 393 </listitem> 394 </varlistentry> 395 396 <varlistentry> 397 <term>-P PID_file</term> 398 <listitem> 399 <para>Path to PID file.</para> 400 </listitem> 401 </varlistentry> 402 403 <varlistentry> 404 <term>-q</term> 405 <listitem> 406 <para>Decrease debugging verbosity (<option>-qq</option> even 407 less).</para> 408 </listitem> 409 </varlistentry> 410 411 <varlistentry> 412 <term>-u</term> 413 <listitem> 414 <para>Enabled DBus control interface. If enabled, interface 415 definitions may be omitted.</para> 416 </listitem> 417 </varlistentry> 418 419 <varlistentry> 420 <term>-v</term> 421 <listitem> 422 <para>Show version.</para> 423 </listitem> 424 </varlistentry> 425 426 <varlistentry> 427 <term>-W</term> 428 <listitem> 429 <para>Wait for a control interface monitor before starting.</para> 430 </listitem> 431 </varlistentry> 432 433 <varlistentry> 434 <term>-N</term> 435 <listitem> 436 <para>Start describing new interface.</para> 437 </listitem> 438 </varlistentry> 439 </variablelist> 440 </refsect1> 441 442 <refsect1> 443 <title>Examples</title> 444 445 <para>In most common cases, <command>wpa_supplicant</command> is 446 started with:</para> 447 448 <blockquote><programlisting> 449 wpa_supplicant -B -c/etc/wpa_supplicant.conf -iwlan0 450 </programlisting></blockquote> 451 452 <para>This makes the process fork into background.</para> 453 454 <para>The easiest way to debug problems, and to get debug log for 455 bug reports, is to start <command>wpa_supplicant</command> on 456 foreground with debugging enabled:</para> 457 458 <blockquote><programlisting> 459 wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d 460 </programlisting></blockquote> 461 462 <para>If the specific driver wrapper is not known beforehand, it is 463 possible to specify multiple comma separated driver wrappers on the command 464 line. <command>wpa_supplicant</command> will use the first driver 465 wrapper that is able to initialize the interface.</para> 466 467 <blockquote><programlisting> 468 wpa_supplicant -Dnl80211,wext -c/etc/wpa_supplicant.conf -iwlan0 469 </programlisting></blockquote> 470 471 <para><command>wpa_supplicant</command> can control multiple 472 interfaces (radios) either by running one process for each 473 interface separately or by running just one process and list of 474 options at command line. Each interface is separated with -N 475 argument. As an example, following command would start 476 wpa_supplicant for two interfaces:</para> 477 478 <blockquote><programlisting> 479 wpa_supplicant \ 480 -c wpa1.conf -i wlan0 -D nl80211 -N \ 481 -c wpa2.conf -i ath0 -D wext 482 </programlisting></blockquote> 483 </refsect1> 484 485 <refsect1> 486 <title>OS Requirements</title> 487 <para>Current hardware/software requirements:</para> 488 489 <itemizedlist> 490 <listitem> 491 <para>Linux kernel 2.4.x or 2.6.x with Linux Wireless 492 Extensions v15 or newer</para> 493 </listitem> 494 495 496 <listitem> 497 <para>FreeBSD 6-CURRENT</para> 498 </listitem> 499 500 <listitem> 501 <para>Microsoft Windows with WinPcap (at least WinXP, may work 502 with other versions)</para> 503 </listitem> 504 </itemizedlist> 505 </refsect1> 506 507 <refsect1> 508 <title>Supported Drivers</title> 509 <variablelist> 510 <varlistentry> 511 <term>Linux wireless extensions</term> 512 <listitem> 513 <para>In theory, any driver that supports Linux wireless 514 extensions can be used with IEEE 802.1X (i.e., not WPA) when 515 using ap_scan=0 option in configuration file.</para> 516 </listitem> 517 </varlistentry> 518 519 <varlistentry> 520 <term>Wired Ethernet drivers</term> 521 <listitem> 522 <para>Use ap_scan=0.</para> 523 </listitem> 524 </varlistentry> 525 526 <varlistentry> 527 <term>BSD net80211 layer (e.g., Atheros driver)</term> 528 <listitem> 529 <para>At the moment, this is for FreeBSD 6-CURRENT branch.</para> 530 </listitem> 531 </varlistentry> 532 533 <varlistentry> 534 <term>Windows NDIS</term> 535 <listitem> 536 <para>The current Windows port requires WinPcap 537 (http://winpcap.polito.it/). See README-Windows.txt for more 538 information.</para> 539 </listitem> 540 </varlistentry> 541 </variablelist> 542 543 544 <para>wpa_supplicant was designed to be portable for different 545 drivers and operating systems. Hopefully, support for more wlan 546 cards and OSes will be added in the future. See developer.txt for 547 more information about the design of wpa_supplicant and porting to 548 other drivers. One main goal is to add full WPA/WPA2 support to 549 Linux wireless extensions to allow new drivers to be supported 550 without having to implement new driver-specific interface code in 551 wpa_supplicant.</para> 552 </refsect1> 553 554 <refsect1> 555 <title>Architecture</title> <para>The 556 <command>wpa_supplicant</command> system consists of the following 557 components:</para> 558 559 <variablelist> 560 <varlistentry> 561 <term><filename>wpa_supplicant.conf</filename> </term> 562 <listitem> 563 <para>the configuration file describing all networks that the 564 user wants the computer to connect to. </para> 565 </listitem> 566 </varlistentry> 567 <varlistentry> 568 <term><command>wpa_supplicant</command></term> 569 <listitem><para>the program that directly interacts with the 570 network interface. </para></listitem> 571 </varlistentry> 572 <varlistentry> 573 <term><command>wpa_cli</command></term> <listitem><para> the 574 client program that provides a high-level interface to the 575 functionality of the daemon. </para></listitem> 576 </varlistentry> 577 <varlistentry> 578 <term><command>wpa_passphrase</command></term> 579 <listitem><para>a utility needed to construct 580 <filename>wpa_supplicant.conf</filename> files that include 581 encrypted passwords.</para></listitem> 582 </varlistentry> 583 </variablelist> 584 </refsect1> 585 586 <refsect1> 587 <title>Quick Start</title> 588 589 <para>First, make a configuration file, e.g. 590 <filename>/etc/wpa_supplicant.conf</filename>, that describes the networks 591 you are interested in. See <citerefentry> 592 <refentrytitle>wpa_supplicant.conf</refentrytitle> 593 <manvolnum>5</manvolnum> 594 </citerefentry> 595 for details.</para> 596 597 <para>Once the configuration is ready, you can test whether the 598 configuration works by running <command>wpa_supplicant</command> 599 with following command to start it on foreground with debugging 600 enabled:</para> 601 602 <blockquote><programlisting> 603 wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -d 604 </programlisting></blockquote> 605 606 <para>Assuming everything goes fine, you can start using following 607 command to start <command>wpa_supplicant</command> on background 608 without debugging:</para> 609 610 <blockquote><programlisting> 611 wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -B 612 </programlisting></blockquote> 613 614 <para>Please note that if you included more than one driver 615 interface in the build time configuration (.config), you may need 616 to specify which interface to use by including -D<driver 617 name> option on the command line.</para> 618 619 <!-- XXX at this point, the page could include a little script 620 based on wpa_cli to wait for a connection and then run 621 dhclient --> 622 623 </refsect1> 624 625 <refsect1> 626 <title>Interface to pcmcia-cs/cardmrg</title> 627 628 <para>For example, following small changes to pcmcia-cs scripts 629 can be used to enable WPA support:</para> 630 631 <para>Add MODE="Managed" and WPA="y" to the network scheme in 632 <filename>/etc/pcmcia/wireless.opts</filename>.</para> 633 634 <para>Add the following block to the end of <emphasis>start</emphasis> 635 action handler in <filename>/etc/pcmcia/wireless</filename>:</para> 636 637 <blockquote><programlisting> 638 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then 639 /usr/local/bin/wpa_supplicant -B -c/etc/wpa_supplicant.conf -i$DEVICE 640 fi 641 </programlisting></blockquote> 642 643 644 <para>Add the following block to the end of <emphasis>stop</emphasis> 645 action handler (may need to be separated from other actions) in 646 <filename>/etc/pcmcia/wireless</filename>:</para> 647 648 <blockquote><programlisting> 649 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then 650 killall wpa_supplicant 651 fi 652 </programlisting></blockquote> 653 654 <para>This will make <command>cardmgr</command> start 655 <command>wpa_supplicant</command> when the card is plugged 656 in.</para> 657 </refsect1> 658 659 <refsect1> 660 <title>See Also</title> 661 <para> 662 <citerefentry> 663 <refentrytitle>wpa_background</refentrytitle> 664 <manvolnum>8</manvolnum> 665 </citerefentry> 666 <citerefentry> 667 <refentrytitle>wpa_supplicant.conf</refentrytitle> 668 <manvolnum>5</manvolnum> 669 </citerefentry> 670 <citerefentry> 671 <refentrytitle>wpa_cli</refentrytitle> 672 <manvolnum>8</manvolnum> 673 </citerefentry> 674 <citerefentry> 675 <refentrytitle>wpa_passphrase</refentrytitle> 676 <manvolnum>8</manvolnum> 677 </citerefentry> 678 </para> 679 </refsect1> 680 <refsect1> 681 <title>Legal</title> 682 <para>wpa_supplicant is copyright (c) 2003-2012, 683 Jouni Malinen <email>j (a] w1.fi</email> and 684 contributors. 685 All Rights Reserved.</para> 686 687 <para>This program is licensed under the BSD license (the one with 688 advertisement clause removed).</para> 689 </refsect1> 690 </refentry> 691
