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>nl80211</term> 250 <listitem> 251 <para>Uses the modern Linux nl80211/cfg80211 netlink-based 252 interface (most new drivers).</para> 253 </listitem> 254 </varlistentry> 255 256 <varlistentry> 257 <term>wext</term> 258 <listitem> 259 <para>Uses the legacy Linux wireless extensions ioctl-based 260 interface (older hardware/drivers).</para> 261 </listitem> 262 </varlistentry> 263 264 <varlistentry> 265 <term>wired</term> 266 <listitem> 267 <para>wpa_supplicant wired Ethernet driver</para> 268 </listitem> 269 </varlistentry> 270 271 <varlistentry> 272 <term>roboswitch</term> 273 <listitem> 274 <para>wpa_supplicant Broadcom switch driver</para> 275 </listitem> 276 </varlistentry> 277 278 <varlistentry> 279 <term>bsd</term> 280 <listitem> 281 <para>BSD 802.11 support (Atheros, etc.).</para> 282 </listitem> 283 </varlistentry> 284 285 <varlistentry> 286 <term>ndis</term> 287 <listitem> 288 <para>Windows NDIS driver.</para> 289 </listitem> 290 </varlistentry> 291 </variablelist> 292 </refsect1> 293 294 <refsect1> 295 <title>Command Line Options</title> 296 <para>Most command line options have global scope. Some are given per 297 interface, and are only valid if at least one <option>-i</option> option 298 is specified, otherwise they're ignored. Option groups for different 299 interfaces must be separated by <option>-N</option> option.</para> 300 <variablelist> 301 <varlistentry> 302 <term>-b br_ifname</term> 303 <listitem> 304 <para>Optional bridge interface name. (Per interface)</para> 305 </listitem> 306 </varlistentry> 307 308 <varlistentry> 309 <term>-B</term> 310 <listitem> 311 <para>Run daemon in the background.</para> 312 </listitem> 313 </varlistentry> 314 315 <varlistentry> 316 <term>-c filename</term> 317 <listitem> 318 <para>Path to configuration file. (Per interface)</para> 319 </listitem> 320 </varlistentry> 321 322 <varlistentry> 323 <term>-C ctrl_interface</term> 324 <listitem> 325 <para>Path to ctrl_interface socket (Per interface. Only used if 326 <option>-c</option> is not).</para> 327 </listitem> 328 </varlistentry> 329 330 <varlistentry> 331 <term>-i ifname</term> 332 <listitem> 333 <para>Interface to listen on. Multiple instances of this option can 334 be present, one per interface, separated by <option>-N</option> 335 option (see below).</para> 336 </listitem> 337 </varlistentry> 338 339 <varlistentry> 340 <term>-d</term> 341 <listitem> 342 <para>Increase debugging verbosity (<option>-dd</option> even 343 more).</para> 344 </listitem> 345 </varlistentry> 346 347 <varlistentry> 348 <term>-D driver</term> 349 <listitem> 350 <para>Driver to use (can be multiple drivers: nl80211,wext). 351 (Per interface, see the available options below.)</para> 352 </listitem> 353 </varlistentry> 354 355 <varlistentry> 356 <term>-e entropy file</term> 357 <listitem> 358 <para>File for <command>wpa_supplicant</command> to use to 359 maintain its internal entropy store in over restarts.</para> 360 </listitem> 361 </varlistentry> 362 363 <varlistentry> 364 <term>-f output file</term> 365 <listitem> 366 <para>Log output to specified file instead of stdout. (This 367 is only available if <command>wpa_supplicant</command> was 368 built with the <literal>CONFIG_DEBUG_FILE</literal> 369 option.)</para> 370 </listitem> 371 </varlistentry> 372 373 <varlistentry> 374 <term>-g global ctrl_interface</term> 375 <listitem> 376 <para>Path to global ctrl_interface socket. If specified, interface 377 definitions may be omitted.</para> 378 </listitem> 379 </varlistentry> 380 381 <varlistentry> 382 <term>-K</term> 383 <listitem> 384 <para>Include keys (passwords, etc.) in debug output.</para> 385 </listitem> 386 </varlistentry> 387 388 <varlistentry> 389 <term>-h</term> 390 <listitem> 391 <para>Help. Show a usage message.</para> 392 </listitem> 393 </varlistentry> 394 395 <varlistentry> 396 <term>-L</term> 397 <listitem> 398 <para>Show license (BSD).</para> 399 </listitem> 400 </varlistentry> 401 402 <varlistentry> 403 <term>-o override driver</term> 404 <listitem> 405 <para>Override the driver parameter for new 406 interfaces.</para> 407 </listitem> 408 </varlistentry> 409 410 <varlistentry> 411 <term>-O override ctrl_interface</term> 412 <listitem> 413 <para>Override the ctrl_interface parameter for new 414 interfaces.</para> 415 </listitem> 416 </varlistentry> 417 418 <varlistentry> 419 <term>-p</term> 420 <listitem> 421 <para>Driver parameters. (Per interface)</para> 422 </listitem> 423 </varlistentry> 424 425 <varlistentry> 426 <term>-P PID_file</term> 427 <listitem> 428 <para>Path to PID file.</para> 429 </listitem> 430 </varlistentry> 431 432 <varlistentry> 433 <term>-q</term> 434 <listitem> 435 <para>Decrease debugging verbosity (<option>-qq</option> even 436 less).</para> 437 </listitem> 438 </varlistentry> 439 440 <varlistentry> 441 <term>-s</term> 442 <listitem> 443 <para>Log output to syslog instead of stdout. (This is only 444 available if <command>wpa_supplicant</command> was built 445 with the <literal>CONFIG_DEBUG_SYSLOG</literal> 446 option.)</para> 447 </listitem> 448 </varlistentry> 449 450 <varlistentry> 451 <term>-T</term> 452 <listitem> 453 <para>Log output to Linux tracing in addition to any other 454 destinations. (This is only available 455 if <command>wpa_supplicant</command> was built with 456 the <literal>CONFIG_DEBUG_LINUX_TRACING</literal> 457 option.)</para> 458 </listitem> 459 </varlistentry> 460 461 <varlistentry> 462 <term>-t</term> 463 <listitem> 464 <para>Include timestamp in debug messages.</para> 465 </listitem> 466 </varlistentry> 467 468 <varlistentry> 469 <term>-u</term> 470 <listitem> 471 <para>Enable DBus control interface. If enabled, interface 472 definitions may be omitted. (This is only available 473 if <command>wpa_supplicant</command> was built with 474 the <literal>CONFIG_CTRL_IFACE_DBUS_NEW</literal> option.)</para> 475 </listitem> 476 </varlistentry> 477 478 <varlistentry> 479 <term>-v</term> 480 <listitem> 481 <para>Show version.</para> 482 </listitem> 483 </varlistentry> 484 485 <varlistentry> 486 <term>-W</term> 487 <listitem> 488 <para>Wait for a control interface monitor before starting.</para> 489 </listitem> 490 </varlistentry> 491 492 <varlistentry> 493 <term>-N</term> 494 <listitem> 495 <para>Start describing new interface.</para> 496 </listitem> 497 </varlistentry> 498 </variablelist> 499 </refsect1> 500 501 <refsect1> 502 <title>Examples</title> 503 504 <para>In most common cases, <command>wpa_supplicant</command> is 505 started with:</para> 506 507<blockquote><programlisting> 508wpa_supplicant -B -c/etc/wpa_supplicant.conf -iwlan0 509</programlisting></blockquote> 510 511 <para>This makes the process fork into background.</para> 512 513 <para>The easiest way to debug problems, and to get debug log for 514 bug reports, is to start <command>wpa_supplicant</command> on 515 foreground with debugging enabled:</para> 516 517<blockquote><programlisting> 518wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d 519</programlisting></blockquote> 520 521 <para>If the specific driver wrapper is not known beforehand, it is 522 possible to specify multiple comma separated driver wrappers on the command 523 line. <command>wpa_supplicant</command> will use the first driver 524 wrapper that is able to initialize the interface.</para> 525 526<blockquote><programlisting> 527wpa_supplicant -Dnl80211,wext -c/etc/wpa_supplicant.conf -iwlan0 528</programlisting></blockquote> 529 530 <para><command>wpa_supplicant</command> can control multiple 531 interfaces (radios) either by running one process for each 532 interface separately or by running just one process and list of 533 options at command line. Each interface is separated with -N 534 argument. As an example, following command would start 535 wpa_supplicant for two interfaces:</para> 536 537<blockquote><programlisting> 538wpa_supplicant \ 539 -c wpa1.conf -i wlan0 -D nl80211 -N \ 540 -c wpa2.conf -i ath0 -D wext 541</programlisting></blockquote> 542 </refsect1> 543 544 <refsect1> 545 <title>OS Requirements</title> 546 <para>Current hardware/software requirements:</para> 547 548 <itemizedlist> 549 <listitem> 550 <para>Linux kernel 2.6.30 or higher with 551 nl80211/cfg80211 support</para> 552 </listitem> 553 554 <listitem> 555 <para>Linux kernel 2.4.x or higher with Linux Wireless 556 Extensions v15 or newer</para> 557 </listitem> 558 559 <listitem> 560 <para>FreeBSD 6-CURRENT</para> 561 </listitem> 562 563 <listitem> 564 <para>Microsoft Windows with WinPcap (at least WinXP, may work 565 with other versions)</para> 566 </listitem> 567 </itemizedlist> 568 </refsect1> 569 570 <refsect1> 571 <title>Supported Drivers</title> 572 <variablelist> 573 <varlistentry> 574 <term>Linux nl80211/cfg80211</term> 575 <listitem> 576 <para>This is the preferred driver for Linux.</para> 577 </listitem> 578 </varlistentry> 579 580 <varlistentry> 581 <term>Linux wireless extensions</term> 582 <listitem> 583 <para>In theory, any driver that supports Linux wireless 584 extensions can be used with IEEE 802.1X (i.e., not WPA) when 585 using ap_scan=0 option in configuration file.</para> 586 </listitem> 587 </varlistentry> 588 589 <varlistentry> 590 <term>Wired Ethernet drivers</term> 591 <listitem> 592 <para>Use ap_scan=0.</para> 593 </listitem> 594 </varlistentry> 595 596 <varlistentry> 597 <term>BSD net80211 layer (e.g., Atheros driver)</term> 598 <listitem> 599 <para>At the moment, this is for FreeBSD 6-CURRENT branch.</para> 600 </listitem> 601 </varlistentry> 602 603 <varlistentry> 604 <term>Windows NDIS</term> 605 <listitem> 606 <para>The current Windows port requires WinPcap 607 (http://winpcap.polito.it/). See README-Windows.txt for more 608 information.</para> 609 </listitem> 610 </varlistentry> 611 </variablelist> 612 613 614 <para>wpa_supplicant was designed to be portable for different 615 drivers and operating systems. Hopefully, support for more wlan 616 cards and OSes will be added in the future. See developer.txt for 617 more information about the design of wpa_supplicant and porting to 618 other drivers. One main goal is to add full WPA/WPA2 support to 619 Linux wireless extensions to allow new drivers to be supported 620 without having to implement new driver-specific interface code in 621 wpa_supplicant.</para> 622 </refsect1> 623 624 <refsect1> 625 <title>Architecture</title> <para>The 626 <command>wpa_supplicant</command> system consists of the following 627 components:</para> 628 629 <variablelist> 630 <varlistentry> 631 <term><filename>wpa_supplicant.conf</filename> </term> 632 <listitem> 633 <para>the configuration file describing all networks that the 634 user wants the computer to connect to. </para> 635 </listitem> 636 </varlistentry> 637 <varlistentry> 638 <term><command>wpa_supplicant</command></term> 639 <listitem><para>the program that directly interacts with the 640 network interface. </para></listitem> 641 </varlistentry> 642 <varlistentry> 643 <term><command>wpa_cli</command></term> <listitem><para> the 644 client program that provides a high-level interface to the 645 functionality of the daemon. </para></listitem> 646 </varlistentry> 647 <varlistentry> 648 <term><command>wpa_passphrase</command></term> 649 <listitem><para>a utility needed to construct 650 <filename>wpa_supplicant.conf</filename> files that include 651 encrypted passwords.</para></listitem> 652 </varlistentry> 653 </variablelist> 654 </refsect1> 655 656 <refsect1> 657 <title>Quick Start</title> 658 659 <para>First, make a configuration file, e.g. 660 <filename>/etc/wpa_supplicant.conf</filename>, that describes the networks 661 you are interested in. See <citerefentry> 662 <refentrytitle>wpa_supplicant.conf</refentrytitle> 663 <manvolnum>5</manvolnum> 664 </citerefentry> 665 for details.</para> 666 667 <para>Once the configuration is ready, you can test whether the 668 configuration works by running <command>wpa_supplicant</command> 669 with following command to start it on foreground with debugging 670 enabled:</para> 671 672 <blockquote><programlisting> 673wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -d 674 </programlisting></blockquote> 675 676 <para>Assuming everything goes fine, you can start using following 677 command to start <command>wpa_supplicant</command> on background 678 without debugging:</para> 679 680 <blockquote><programlisting> 681wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -B 682 </programlisting></blockquote> 683 684 <para>Please note that if you included more than one driver 685 interface in the build time configuration (.config), you may need 686 to specify which interface to use by including -D<driver 687 name> option on the command line.</para> 688 689 <!-- XXX at this point, the page could include a little script 690 based on wpa_cli to wait for a connection and then run 691 dhclient --> 692 693 </refsect1> 694 695 <refsect1> 696 <title>Interface to pcmcia-cs/cardmrg</title> 697 698 <para>For example, following small changes to pcmcia-cs scripts 699 can be used to enable WPA support:</para> 700 701 <para>Add MODE="Managed" and WPA="y" to the network scheme in 702 <filename>/etc/pcmcia/wireless.opts</filename>.</para> 703 704 <para>Add the following block to the end of <emphasis>start</emphasis> 705 action handler in <filename>/etc/pcmcia/wireless</filename>:</para> 706 707 <blockquote><programlisting> 708if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then 709 /usr/local/bin/wpa_supplicant -B -c/etc/wpa_supplicant.conf -i$DEVICE 710fi 711 </programlisting></blockquote> 712 713 714 <para>Add the following block to the end of <emphasis>stop</emphasis> 715 action handler (may need to be separated from other actions) in 716 <filename>/etc/pcmcia/wireless</filename>:</para> 717 718 <blockquote><programlisting> 719if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then 720 killall wpa_supplicant 721fi 722 </programlisting></blockquote> 723 724 <para>This will make <command>cardmgr</command> start 725 <command>wpa_supplicant</command> when the card is plugged 726 in.</para> 727 </refsect1> 728 729 <refsect1> 730 <title>See Also</title> 731 <para> 732 <citerefentry> 733 <refentrytitle>wpa_background</refentrytitle> 734 <manvolnum>8</manvolnum> 735 </citerefentry> 736 <citerefentry> 737 <refentrytitle>wpa_supplicant.conf</refentrytitle> 738 <manvolnum>5</manvolnum> 739 </citerefentry> 740 <citerefentry> 741 <refentrytitle>wpa_cli</refentrytitle> 742 <manvolnum>8</manvolnum> 743 </citerefentry> 744 <citerefentry> 745 <refentrytitle>wpa_passphrase</refentrytitle> 746 <manvolnum>8</manvolnum> 747 </citerefentry> 748 </para> 749 </refsect1> 750 <refsect1> 751 <title>Legal</title> 752 <para>wpa_supplicant is copyright (c) 2003-2019, 753 Jouni Malinen <email>j@w1.fi</email> and 754 contributors. 755 All Rights Reserved.</para> 756 757 <para>This program is licensed under the BSD license (the one with 758 advertisement clause removed).</para> 759 </refsect1> 760</refentry> 761