1WPA Supplicant 2============== 3 4Copyright (c) 2003-2009, Jouni Malinen <j@w1.fi> and contributors 5All Rights Reserved. 6 7This program is dual-licensed under both the GPL version 2 and BSD 8license. Either license may be used at your option. 9 10 11 12License 13------- 14 15GPL v2: 16 17This program is free software; you can redistribute it and/or modify 18it under the terms of the GNU General Public License version 2 as 19published by the Free Software Foundation. 20 21This program is distributed in the hope that it will be useful, 22but WITHOUT ANY WARRANTY; without even the implied warranty of 23MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 24GNU General Public License for more details. 25 26You should have received a copy of the GNU General Public License 27along with this program; if not, write to the Free Software 28Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 29 30(this copy of the license is in COPYING file) 31 32 33Alternatively, this software may be distributed, used, and modified 34under the terms of BSD license: 35 36Redistribution and use in source and binary forms, with or without 37modification, are permitted provided that the following conditions are 38met: 39 401. Redistributions of source code must retain the above copyright 41 notice, this list of conditions and the following disclaimer. 42 432. Redistributions in binary form must reproduce the above copyright 44 notice, this list of conditions and the following disclaimer in the 45 documentation and/or other materials provided with the distribution. 46 473. Neither the name(s) of the above-listed copyright holder(s) nor the 48 names of its contributors may be used to endorse or promote products 49 derived from this software without specific prior written permission. 50 51THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 52"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 53LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 54A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 55OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 56SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 57LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 58DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 59THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 60(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 61OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 62 63 64 65Features 66-------- 67 68Supported WPA/IEEE 802.11i features: 69- WPA-PSK ("WPA-Personal") 70- WPA with EAP (e.g., with RADIUS authentication server) ("WPA-Enterprise") 71 Following authentication methods are supported with an integrate IEEE 802.1X 72 Supplicant: 73 * EAP-TLS 74 * EAP-PEAP/MSCHAPv2 (both PEAPv0 and PEAPv1) 75 * EAP-PEAP/TLS (both PEAPv0 and PEAPv1) 76 * EAP-PEAP/GTC (both PEAPv0 and PEAPv1) 77 * EAP-PEAP/OTP (both PEAPv0 and PEAPv1) 78 * EAP-PEAP/MD5-Challenge (both PEAPv0 and PEAPv1) 79 * EAP-TTLS/EAP-MD5-Challenge 80 * EAP-TTLS/EAP-GTC 81 * EAP-TTLS/EAP-OTP 82 * EAP-TTLS/EAP-MSCHAPv2 83 * EAP-TTLS/EAP-TLS 84 * EAP-TTLS/MSCHAPv2 85 * EAP-TTLS/MSCHAP 86 * EAP-TTLS/PAP 87 * EAP-TTLS/CHAP 88 * EAP-SIM 89 * EAP-AKA 90 * EAP-PSK 91 * EAP-PAX 92 * EAP-SAKE 93 * EAP-IKEv2 94 * EAP-GPSK 95 * LEAP (note: requires special support from the driver for IEEE 802.11 96 authentication) 97 (following methods are supported, but since they do not generate keying 98 material, they cannot be used with WPA or IEEE 802.1X WEP keying) 99 * EAP-MD5-Challenge 100 * EAP-MSCHAPv2 101 * EAP-GTC 102 * EAP-OTP 103- key management for CCMP, TKIP, WEP104, WEP40 104- RSN/WPA2 (IEEE 802.11i) 105 * pre-authentication 106 * PMKSA caching 107 108Supported TLS/crypto libraries: 109- OpenSSL (default) 110- GnuTLS 111 112Internal TLS/crypto implementation (optional): 113- can be used in place of an external TLS/crypto library 114- TLSv1 115- X.509 certificate processing 116- PKCS #1 117- ASN.1 118- RSA 119- bignum 120- minimal size (ca. 50 kB binary, parts of which are already needed for WPA; 121 TLSv1/X.509/ASN.1/RSA/bignum parts are about 25 kB on x86) 122 123 124Requirements 125------------ 126 127Current hardware/software requirements: 128- Linux kernel 2.4.x or 2.6.x with Linux Wireless Extensions v15 or newer 129- FreeBSD 6-CURRENT 130- NetBSD-current 131- Microsoft Windows with WinPcap (at least WinXP, may work with other versions) 132- drivers: 133 Linux drivers that support WPA/WPA2 configuration with the generic 134 Linux wireless extensions (WE-18 or newer). Even though there are 135 number of driver specific interface included in wpa_supplicant, please 136 note that Linux drivers are moving to use generic wireless extensions 137 and driver_wext (-Dwext on wpa_supplicant command line) should be the 138 default option to start with before falling back to driver specific 139 interface. 140 141 Host AP driver for Prism2/2.5/3 (development snapshot/v0.2.x) 142 (http://hostap.epitest.fi/) 143 Driver need to be set in Managed mode ('iwconfig wlan0 mode managed'). 144 Please note that station firmware version needs to be 1.7.0 or newer 145 to work in WPA mode. 146 147 Linuxant DriverLoader (http://www.linuxant.com/driverloader/) 148 with Windows NDIS driver for your wlan card supporting WPA. 149 150 Agere Systems Inc. Linux Driver 151 (http://www.agere.com/support/drivers/) 152 Please note that the driver interface file (driver_hermes.c) and 153 hardware specific include files are not included in the 154 wpa_supplicant distribution. You will need to copy these from the 155 source package of the Agere driver. 156 157 madwifi driver for cards based on Atheros chip set (ar521x) 158 (http://sourceforge.net/projects/madwifi/) 159 Please note that you will need to modify the wpa_supplicant .config 160 file to use the correct path for the madwifi driver root directory 161 (CFLAGS += -I../madwifi/wpa line in example defconfig). 162 163 ATMEL AT76C5XXx driver for USB and PCMCIA cards 164 (http://atmelwlandriver.sourceforge.net/). 165 166 Linux ndiswrapper (http://ndiswrapper.sourceforge.net/) with 167 Windows NDIS driver. 168 169 Broadcom wl.o driver (old version only) 170 This is a generic Linux driver for Broadcom IEEE 802.11a/g cards. 171 However, it is proprietary driver that is not publicly available 172 except for couple of exceptions, mainly Broadcom-based APs/wireless 173 routers that use Linux. The driver binary can be downloaded, e.g., 174 from Linksys support site (http://www.linksys.com/support/gpl.asp) 175 for Linksys WRT54G. The GPL tarball includes cross-compiler and 176 the needed header file, wlioctl.h, for compiling wpa_supplicant. 177 This driver support in wpa_supplicant is expected to work also with 178 other devices based on Broadcom driver (assuming the driver includes 179 client mode support). Please note that the newer Broadcom driver 180 ("hybrid Linux driver") supports Linux wireless extensions and does 181 not need (or even work) with the specific driver wrapper. Use -Dwext 182 with that driver. 183 184 Intel ipw2100 driver 185 (http://sourceforge.net/projects/ipw2100/) 186 187 Intel ipw2200 driver 188 (http://sourceforge.net/projects/ipw2200/) 189 190 In theory, any driver that supports Linux wireless extensions can be 191 used with IEEE 802.1X (i.e., not WPA) when using ap_scan=0 option in 192 configuration file. 193 194 Wired Ethernet drivers (with ap_scan=0) 195 196 BSD net80211 layer (e.g., Atheros driver) 197 At the moment, this is for FreeBSD 6-CURRENT branch and NetBSD-current. 198 199 Windows NDIS 200 The current Windows port requires WinPcap (http://winpcap.polito.it/). 201 See README-Windows.txt for more information. 202 203wpa_supplicant was designed to be portable for different drivers and 204operating systems. Hopefully, support for more wlan cards and OSes will be 205added in the future. See developer's documentation 206(http://hostap.epitest.fi/wpa_supplicant/devel/) for more information about the 207design of wpa_supplicant and porting to other drivers. One main goal 208is to add full WPA/WPA2 support to Linux wireless extensions to allow 209new drivers to be supported without having to implement new 210driver-specific interface code in wpa_supplicant. 211 212Optional libraries for layer2 packet processing: 213- libpcap (tested with 0.7.2, most relatively recent versions assumed to work, 214 this is likely to be available with most distributions, 215 http://tcpdump.org/) 216- libdnet (tested with v1.4, most versions assumed to work, 217 http://libdnet.sourceforge.net/) 218 219These libraries are _not_ used in the default Linux build. Instead, 220internal Linux specific implementation is used. libpcap/libdnet are 221more portable and they can be used by adding CONFIG_L2_PACKET=pcap into 222.config. They may also be selected automatically for other operating 223systems. In case of Windows builds, WinPcap is used by default 224(CONFIG_L2_PACKET=winpcap). 225 226 227Optional libraries for EAP-TLS, EAP-PEAP, and EAP-TTLS: 228- OpenSSL (tested with 0.9.7c and 0.9.7d, and 0.9.8 versions; assumed to 229 work with most relatively recent versions; this is likely to be 230 available with most distributions, http://www.openssl.org/) 231- GnuTLS 232- internal TLSv1 implementation 233 234TLS options for EAP-FAST: 235- OpenSSL 0.9.8d _with_ openssl-0.9.8d-tls-extensions.patch applied 236 (i.e., the default OpenSSL package does not include support for 237 extensions needed for EAP-FAST) 238- internal TLSv1 implementation 239 240One of these libraries is needed when EAP-TLS, EAP-PEAP, EAP-TTLS, or 241EAP-FAST support is enabled. WPA-PSK mode does not require this or EAPOL/EAP 242implementation. A configuration file, .config, for compilation is 243needed to enable IEEE 802.1X/EAPOL and EAP methods. Note that EAP-MD5, 244EAP-GTC, EAP-OTP, and EAP-MSCHAPV2 cannot be used alone with WPA, so 245they should only be enabled if testing the EAPOL/EAP state 246machines. However, there can be used as inner authentication 247algorithms with EAP-PEAP and EAP-TTLS. 248 249See Building and installing section below for more detailed 250information about the wpa_supplicant build time configuration. 251 252 253 254WPA 255--- 256 257The original security mechanism of IEEE 802.11 standard was not 258designed to be strong and has proven to be insufficient for most 259networks that require some kind of security. Task group I (Security) 260of IEEE 802.11 working group (http://www.ieee802.org/11/) has worked 261to address the flaws of the base standard and has in practice 262completed its work in May 2004. The IEEE 802.11i amendment to the IEEE 263802.11 standard was approved in June 2004 and published in July 2004. 264 265Wi-Fi Alliance (http://www.wi-fi.org/) used a draft version of the 266IEEE 802.11i work (draft 3.0) to define a subset of the security 267enhancements that can be implemented with existing wlan hardware. This 268is called Wi-Fi Protected Access<TM> (WPA). This has now become a 269mandatory component of interoperability testing and certification done 270by Wi-Fi Alliance. Wi-Fi provides information about WPA at its web 271site (http://www.wi-fi.org/OpenSection/protected_access.asp). 272 273IEEE 802.11 standard defined wired equivalent privacy (WEP) algorithm 274for protecting wireless networks. WEP uses RC4 with 40-bit keys, 27524-bit initialization vector (IV), and CRC32 to protect against packet 276forgery. All these choices have proven to be insufficient: key space is 277too small against current attacks, RC4 key scheduling is insufficient 278(beginning of the pseudorandom stream should be skipped), IV space is 279too small and IV reuse makes attacks easier, there is no replay 280protection, and non-keyed authentication does not protect against bit 281flipping packet data. 282 283WPA is an intermediate solution for the security issues. It uses 284Temporal Key Integrity Protocol (TKIP) to replace WEP. TKIP is a 285compromise on strong security and possibility to use existing 286hardware. It still uses RC4 for the encryption like WEP, but with 287per-packet RC4 keys. In addition, it implements replay protection, 288keyed packet authentication mechanism (Michael MIC). 289 290Keys can be managed using two different mechanisms. WPA can either use 291an external authentication server (e.g., RADIUS) and EAP just like 292IEEE 802.1X is using or pre-shared keys without need for additional 293servers. Wi-Fi calls these "WPA-Enterprise" and "WPA-Personal", 294respectively. Both mechanisms will generate a master session key for 295the Authenticator (AP) and Supplicant (client station). 296 297WPA implements a new key handshake (4-Way Handshake and Group Key 298Handshake) for generating and exchanging data encryption keys between 299the Authenticator and Supplicant. This handshake is also used to 300verify that both Authenticator and Supplicant know the master session 301key. These handshakes are identical regardless of the selected key 302management mechanism (only the method for generating master session 303key changes). 304 305 306 307IEEE 802.11i / WPA2 308------------------- 309 310The design for parts of IEEE 802.11i that were not included in WPA has 311finished (May 2004) and this amendment to IEEE 802.11 was approved in 312June 2004. Wi-Fi Alliance is using the final IEEE 802.11i as a new 313version of WPA called WPA2. This includes, e.g., support for more 314robust encryption algorithm (CCMP: AES in Counter mode with CBC-MAC) 315to replace TKIP and optimizations for handoff (reduced number of 316messages in initial key handshake, pre-authentication, and PMKSA caching). 317 318 319 320wpa_supplicant 321-------------- 322 323wpa_supplicant is an implementation of the WPA Supplicant component, 324i.e., the part that runs in the client stations. It implements WPA key 325negotiation with a WPA Authenticator and EAP authentication with 326Authentication Server. In addition, it controls the roaming and IEEE 327802.11 authentication/association of the wlan driver. 328 329wpa_supplicant is designed to be a "daemon" program that runs in the 330background and acts as the backend component controlling the wireless 331connection. wpa_supplicant supports separate frontend programs and an 332example text-based frontend, wpa_cli, is included with wpa_supplicant. 333 334Following steps are used when associating with an AP using WPA: 335 336- wpa_supplicant requests the kernel driver to scan neighboring BSSes 337- wpa_supplicant selects a BSS based on its configuration 338- wpa_supplicant requests the kernel driver to associate with the chosen 339 BSS 340- If WPA-EAP: integrated IEEE 802.1X Supplicant completes EAP 341 authentication with the authentication server (proxied by the 342 Authenticator in the AP) 343- If WPA-EAP: master key is received from the IEEE 802.1X Supplicant 344- If WPA-PSK: wpa_supplicant uses PSK as the master session key 345- wpa_supplicant completes WPA 4-Way Handshake and Group Key Handshake 346 with the Authenticator (AP) 347- wpa_supplicant configures encryption keys for unicast and broadcast 348- normal data packets can be transmitted and received 349 350 351 352Building and installing 353----------------------- 354 355In order to be able to build wpa_supplicant, you will first need to 356select which parts of it will be included. This is done by creating a 357build time configuration file, .config, in the wpa_supplicant root 358directory. Configuration options are text lines using following 359format: CONFIG_<option>=y. Lines starting with # are considered 360comments and are ignored. See defconfig file for an example configuration 361and a list of available options and additional notes. 362 363The build time configuration can be used to select only the needed 364features and limit the binary size and requirements for external 365libraries. The main configuration parts are the selection of which 366driver interfaces (e.g., hostap, madwifi, ..) and which authentication 367methods (e.g., EAP-TLS, EAP-PEAP, ..) are included. 368 369Following build time configuration options are used to control IEEE 370802.1X/EAPOL and EAP state machines and all EAP methods. Including 371TLS, PEAP, or TTLS will require linking wpa_supplicant with OpenSSL 372library for TLS implementation. Alternatively, GnuTLS or the internal 373TLSv1 implementation can be used for TLS functionaly. 374 375CONFIG_IEEE8021X_EAPOL=y 376CONFIG_EAP_MD5=y 377CONFIG_EAP_MSCHAPV2=y 378CONFIG_EAP_TLS=y 379CONFIG_EAP_PEAP=y 380CONFIG_EAP_TTLS=y 381CONFIG_EAP_GTC=y 382CONFIG_EAP_OTP=y 383CONFIG_EAP_SIM=y 384CONFIG_EAP_AKA=y 385CONFIG_EAP_PSK=y 386CONFIG_EAP_SAKE=y 387CONFIG_EAP_GPSK=y 388CONFIG_EAP_PAX=y 389CONFIG_EAP_LEAP=y 390CONFIG_EAP_IKEV2=y 391 392Following option can be used to include GSM SIM/USIM interface for GSM/UMTS 393authentication algorithm (for EAP-SIM/EAP-AKA). This requires pcsc-lite 394(http://www.linuxnet.com/) for smart card access. 395 396CONFIG_PCSC=y 397 398Following options can be added to .config to select which driver 399interfaces are included. Hermes driver interface needs to be downloaded 400from Agere (see above). 401 402CONFIG_DRIVER_HOSTAP=y 403CONFIG_DRIVER_HERMES=y 404CONFIG_DRIVER_MADWIFI=y 405CONFIG_DRIVER_ATMEL=y 406CONFIG_DRIVER_WEXT=y 407CONFIG_DRIVER_RALINK=y 408CONFIG_DRIVER_NDISWRAPPER=y 409CONFIG_DRIVER_BROADCOM=y 410CONFIG_DRIVER_IPW=y 411CONFIG_DRIVER_BSD=y 412CONFIG_DRIVER_NDIS=y 413 414Following example includes all features and driver interfaces that are 415included in the wpa_supplicant package: 416 417CONFIG_DRIVER_HOSTAP=y 418CONFIG_DRIVER_HERMES=y 419CONFIG_DRIVER_MADWIFI=y 420CONFIG_DRIVER_ATMEL=y 421CONFIG_DRIVER_WEXT=y 422CONFIG_DRIVER_NDISWRAPPER=y 423CONFIG_DRIVER_BROADCOM=y 424CONFIG_DRIVER_IPW=y 425CONFIG_DRIVER_BSD=y 426CONFIG_DRIVER_NDIS=y 427CONFIG_IEEE8021X_EAPOL=y 428CONFIG_EAP_MD5=y 429CONFIG_EAP_MSCHAPV2=y 430CONFIG_EAP_TLS=y 431CONFIG_EAP_PEAP=y 432CONFIG_EAP_TTLS=y 433CONFIG_EAP_GTC=y 434CONFIG_EAP_OTP=y 435CONFIG_EAP_SIM=y 436CONFIG_EAP_AKA=y 437CONFIG_EAP_PSK=y 438CONFIG_EAP_SAKE=y 439CONFIG_EAP_GPSK=y 440CONFIG_EAP_PAX=y 441CONFIG_EAP_LEAP=y 442CONFIG_EAP_IKEV2=y 443CONFIG_PCSC=y 444 445EAP-PEAP and EAP-TTLS will automatically include configured EAP 446methods (MD5, OTP, GTC, MSCHAPV2) for inner authentication selection. 447 448 449After you have created a configuration file, you can build 450wpa_supplicant and wpa_cli with 'make' command. You may then install 451the binaries to a suitable system directory, e.g., /usr/local/bin. 452 453Example commands: 454 455# build wpa_supplicant and wpa_cli 456make 457# install binaries (this may need root privileges) 458cp wpa_cli wpa_supplicant /usr/local/bin 459 460 461You will need to make a configuration file, e.g., 462/etc/wpa_supplicant.conf, with network configuration for the networks 463you are going to use. Configuration file section below includes 464explanation fo the configuration file format and includes various 465examples. Once the configuration is ready, you can test whether the 466configuration work by first running wpa_supplicant with following 467command to start it on foreground with debugging enabled: 468 469wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -d 470 471Assuming everything goes fine, you can start using following command 472to start wpa_supplicant on background without debugging: 473 474wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -B 475 476Please note that if you included more than one driver interface in the 477build time configuration (.config), you may need to specify which 478interface to use by including -D<driver name> option on the command 479line. See following section for more details on command line options 480for wpa_supplicant. 481 482 483 484Command line options 485-------------------- 486 487usage: 488 wpa_supplicant [-BddfhKLqqtuvwW] [-P<pid file>] [-g<global ctrl>] \ 489 -i<ifname> -c<config file> [-C<ctrl>] [-D<driver>] [-p<driver_param>] \ 490 [-b<br_ifname> [-N -i<ifname> -c<conf> [-C<ctrl>] [-D<driver>] \ 491 [-p<driver_param>] [-b<br_ifname>] ...] 492 493options: 494 -b = optional bridge interface name 495 -B = run daemon in the background 496 -c = Configuration file 497 -C = ctrl_interface parameter (only used if -c is not) 498 -i = interface name 499 -d = increase debugging verbosity (-dd even more) 500 -D = driver name 501 -f = Log output to default log location (normally /tmp) 502 -g = global ctrl_interface 503 -K = include keys (passwords, etc.) in debug output 504 -t = include timestamp in debug messages 505 -h = show this help text 506 -L = show license (GPL and BSD) 507 -p = driver parameters 508 -P = PID file 509 -q = decrease debugging verbosity (-qq even less) 510 -u = enable DBus control interface 511 -v = show version 512 -w = wait for interface to be added, if needed 513 -W = wait for a control interface monitor before starting 514 -N = start describing new interface 515 516drivers: 517 hostap = Host AP driver (Intersil Prism2/2.5/3) [default] 518 (this can also be used with Linuxant DriverLoader) 519 hermes = Agere Systems Inc. driver (Hermes-I/Hermes-II) 520 madwifi = MADWIFI 802.11 support (Atheros, etc.) (deprecated; use wext) 521 atmel = ATMEL AT76C5XXx (USB, PCMCIA) 522 wext = Linux wireless extensions (generic) 523 ralink = Ralink Client driver 524 ndiswrapper = Linux ndiswrapper (deprecated; use wext) 525 broadcom = Broadcom wl.o driver 526 ipw = Intel ipw2100/2200 driver (old; use wext with Linux 2.6.13 or newer) 527 wired = wpa_supplicant wired Ethernet driver 528 roboswitch = wpa_supplicant Broadcom switch driver 529 bsd = BSD 802.11 support (Atheros, etc.) 530 ndis = Windows NDIS driver 531 532In most common cases, wpa_supplicant is started with 533 534wpa_supplicant -B -c/etc/wpa_supplicant.conf -iwlan0 535 536This makes the process fork into background. 537 538The easiest way to debug problems, and to get debug log for bug 539reports, is to start wpa_supplicant on foreground with debugging 540enabled: 541 542wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d 543 544 545wpa_supplicant can control multiple interfaces (radios) either by 546running one process for each interface separately or by running just 547one process and list of options at command line. Each interface is 548separated with -N argument. As an example, following command would 549start wpa_supplicant for two interfaces: 550 551wpa_supplicant \ 552 -c wpa1.conf -i wlan0 -D hostap -N \ 553 -c wpa2.conf -i ath0 -D madwifi 554 555 556If the interface is added in a Linux bridge (e.g., br0), the bridge 557interface needs to be configured to wpa_supplicant in addition to the 558main interface: 559 560wpa_supplicant -cw.conf -Dmadwifi -iath0 -bbr0 561 562 563Configuration file 564------------------ 565 566wpa_supplicant is configured using a text file that lists all accepted 567networks and security policies, including pre-shared keys. See 568example configuration file, wpa_supplicant.conf, for detailed 569information about the configuration format and supported fields. 570 571Changes to configuration file can be reloaded be sending SIGHUP signal 572to wpa_supplicant ('killall -HUP wpa_supplicant'). Similarly, 573reloading can be triggered with 'wpa_cli reconfigure' command. 574 575Configuration file can include one or more network blocks, e.g., one 576for each used SSID. wpa_supplicant will automatically select the best 577betwork based on the order of network blocks in the configuration 578file, network security level (WPA/WPA2 is preferred), and signal 579strength. 580 581Example configuration files for some common configurations: 582 5831) WPA-Personal (PSK) as home network and WPA-Enterprise with EAP-TLS as work 584 network 585 586# allow frontend (e.g., wpa_cli) to be used by all users in 'wheel' group 587ctrl_interface=/var/run/wpa_supplicant 588ctrl_interface_group=wheel 589# 590# home network; allow all valid ciphers 591network={ 592 ssid="home" 593 scan_ssid=1 594 key_mgmt=WPA-PSK 595 psk="very secret passphrase" 596} 597# 598# work network; use EAP-TLS with WPA; allow only CCMP and TKIP ciphers 599network={ 600 ssid="work" 601 scan_ssid=1 602 key_mgmt=WPA-EAP 603 pairwise=CCMP TKIP 604 group=CCMP TKIP 605 eap=TLS 606 identity="user@example.com" 607 ca_cert="/etc/cert/ca.pem" 608 client_cert="/etc/cert/user.pem" 609 private_key="/etc/cert/user.prv" 610 private_key_passwd="password" 611} 612 613 6142) WPA-RADIUS/EAP-PEAP/MSCHAPv2 with RADIUS servers that use old peaplabel 615 (e.g., Funk Odyssey and SBR, Meetinghouse Aegis, Interlink RAD-Series) 616 617ctrl_interface=/var/run/wpa_supplicant 618ctrl_interface_group=wheel 619network={ 620 ssid="example" 621 scan_ssid=1 622 key_mgmt=WPA-EAP 623 eap=PEAP 624 identity="user@example.com" 625 password="foobar" 626 ca_cert="/etc/cert/ca.pem" 627 phase1="peaplabel=0" 628 phase2="auth=MSCHAPV2" 629} 630 631 6323) EAP-TTLS/EAP-MD5-Challenge configuration with anonymous identity for the 633 unencrypted use. Real identity is sent only within an encrypted TLS tunnel. 634 635ctrl_interface=/var/run/wpa_supplicant 636ctrl_interface_group=wheel 637network={ 638 ssid="example" 639 scan_ssid=1 640 key_mgmt=WPA-EAP 641 eap=TTLS 642 identity="user@example.com" 643 anonymous_identity="anonymous@example.com" 644 password="foobar" 645 ca_cert="/etc/cert/ca.pem" 646 phase2="auth=MD5" 647} 648 649 6504) IEEE 802.1X (i.e., no WPA) with dynamic WEP keys (require both unicast and 651 broadcast); use EAP-TLS for authentication 652 653ctrl_interface=/var/run/wpa_supplicant 654ctrl_interface_group=wheel 655network={ 656 ssid="1x-test" 657 scan_ssid=1 658 key_mgmt=IEEE8021X 659 eap=TLS 660 identity="user@example.com" 661 ca_cert="/etc/cert/ca.pem" 662 client_cert="/etc/cert/user.pem" 663 private_key="/etc/cert/user.prv" 664 private_key_passwd="password" 665 eapol_flags=3 666} 667 668 6695) Catch all example that allows more or less all configuration modes. The 670 configuration options are used based on what security policy is used in the 671 selected SSID. This is mostly for testing and is not recommended for normal 672 use. 673 674ctrl_interface=/var/run/wpa_supplicant 675ctrl_interface_group=wheel 676network={ 677 ssid="example" 678 scan_ssid=1 679 key_mgmt=WPA-EAP WPA-PSK IEEE8021X NONE 680 pairwise=CCMP TKIP 681 group=CCMP TKIP WEP104 WEP40 682 psk="very secret passphrase" 683 eap=TTLS PEAP TLS 684 identity="user@example.com" 685 password="foobar" 686 ca_cert="/etc/cert/ca.pem" 687 client_cert="/etc/cert/user.pem" 688 private_key="/etc/cert/user.prv" 689 private_key_passwd="password" 690 phase1="peaplabel=0" 691 ca_cert2="/etc/cert/ca2.pem" 692 client_cert2="/etc/cer/user.pem" 693 private_key2="/etc/cer/user.prv" 694 private_key2_passwd="password" 695} 696 697 6986) Authentication for wired Ethernet. This can be used with 'wired' or 699 'roboswitch' interface (-Dwired or -Droboswitch on command line). 700 701ctrl_interface=/var/run/wpa_supplicant 702ctrl_interface_group=wheel 703ap_scan=0 704network={ 705 key_mgmt=IEEE8021X 706 eap=MD5 707 identity="user" 708 password="password" 709 eapol_flags=0 710} 711 712 713 714Certificates 715------------ 716 717Some EAP authentication methods require use of certificates. EAP-TLS 718uses both server side and client certificates whereas EAP-PEAP and 719EAP-TTLS only require the server side certificate. When client 720certificate is used, a matching private key file has to also be 721included in configuration. If the private key uses a passphrase, this 722has to be configured in wpa_supplicant.conf ("private_key_passwd"). 723 724wpa_supplicant supports X.509 certificates in PEM and DER 725formats. User certificate and private key can be included in the same 726file. 727 728If the user certificate and private key is received in PKCS#12/PFX 729format, they need to be converted to suitable PEM/DER format for 730wpa_supplicant. This can be done, e.g., with following commands: 731 732# convert client certificate and private key to PEM format 733openssl pkcs12 -in example.pfx -out user.pem -clcerts 734# convert CA certificate (if included in PFX file) to PEM format 735openssl pkcs12 -in example.pfx -out ca.pem -cacerts -nokeys 736 737 738 739wpa_cli 740------- 741 742wpa_cli is a text-based frontend program for interacting with 743wpa_supplicant. It is used to query current status, change 744configuration, trigger events, and request interactive user input. 745 746wpa_cli can show the current authentication status, selected security 747mode, dot11 and dot1x MIBs, etc. In addition, it can configure some 748variables like EAPOL state machine parameters and trigger events like 749reassociation and IEEE 802.1X logoff/logon. wpa_cli provides a user 750interface to request authentication information, like username and 751password, if these are not included in the configuration. This can be 752used to implement, e.g., one-time-passwords or generic token card 753authentication where the authentication is based on a 754challenge-response that uses an external device for generating the 755response. 756 757The control interface of wpa_supplicant can be configured to allow 758non-root user access (ctrl_interface_group in the configuration 759file). This makes it possible to run wpa_cli with a normal user 760account. 761 762wpa_cli supports two modes: interactive and command line. Both modes 763share the same command set and the main difference is in interactive 764mode providing access to unsolicited messages (event messages, 765username/password requests). 766 767Interactive mode is started when wpa_cli is executed without including 768the command as a command line parameter. Commands are then entered on 769the wpa_cli prompt. In command line mode, the same commands are 770entered as command line arguments for wpa_cli. 771 772 773Interactive authentication parameters request 774 775When wpa_supplicant need authentication parameters, like username and 776password, which are not present in the configuration file, it sends a 777request message to all attached frontend programs, e.g., wpa_cli in 778interactive mode. wpa_cli shows these requests with 779"CTRL-REQ-<type>-<id>:<text>" prefix. <type> is IDENTITY, PASSWORD, or 780OTP (one-time-password). <id> is a unique identifier for the current 781network. <text> is description of the request. In case of OTP request, 782it includes the challenge from the authentication server. 783 784The reply to these requests can be given with 'identity', 'password', 785and 'otp' commands. <id> needs to be copied from the the matching 786request. 'password' and 'otp' commands can be used regardless of 787whether the request was for PASSWORD or OTP. The main difference 788between these two commands is that values given with 'password' are 789remembered as long as wpa_supplicant is running whereas values given 790with 'otp' are used only once and then forgotten, i.e., wpa_supplicant 791will ask frontend for a new value for every use. This can be used to 792implement one-time-password lists and generic token card -based 793authentication. 794 795Example request for password and a matching reply: 796 797CTRL-REQ-PASSWORD-1:Password needed for SSID foobar 798> password 1 mysecretpassword 799 800Example request for generic token card challenge-response: 801 802CTRL-REQ-OTP-2:Challenge 1235663 needed for SSID foobar 803> otp 2 9876 804 805 806wpa_cli commands 807 808 status = get current WPA/EAPOL/EAP status 809 mib = get MIB variables (dot1x, dot11) 810 help = show this usage help 811 interface [ifname] = show interfaces/select interface 812 level <debug level> = change debug level 813 license = show full wpa_cli license 814 logoff = IEEE 802.1X EAPOL state machine logoff 815 logon = IEEE 802.1X EAPOL state machine logon 816 set = set variables (shows list of variables when run without arguments) 817 pmksa = show PMKSA cache 818 reassociate = force reassociation 819 reconfigure = force wpa_supplicant to re-read its configuration file 820 preauthenticate <BSSID> = force preauthentication 821 identity <network id> <identity> = configure identity for an SSID 822 password <network id> <password> = configure password for an SSID 823 pin <network id> <pin> = configure pin for an SSID 824 otp <network id> <password> = configure one-time-password for an SSID 825 passphrase <network id> <passphrase> = configure private key passphrase 826 for an SSID 827 bssid <network id> <BSSID> = set preferred BSSID for an SSID 828 list_networks = list configured networks 829 select_network <network id> = select a network (disable others) 830 enable_network <network id> = enable a network 831 disable_network <network id> = disable a network 832 add_network = add a network 833 remove_network <network id> = remove a network 834 set_network <network id> <variable> <value> = set network variables (shows 835 list of variables when run without arguments) 836 get_network <network id> <variable> = get network variables 837 save_config = save the current configuration 838 disconnect = disconnect and wait for reassociate command before connecting 839 scan = request new BSS scan 840 scan_results = get latest scan results 841 get_capability <eap/pairwise/group/key_mgmt/proto/auth_alg> = get capabilies 842 terminate = terminate wpa_supplicant 843 quit = exit wpa_cli 844 845 846wpa_cli command line options 847 848wpa_cli [-p<path to ctrl sockets>] [-i<ifname>] [-hvB] [-a<action file>] \ 849 [-P<pid file>] [-g<global ctrl>] [command..] 850 -h = help (show this usage text) 851 -v = shown version information 852 -a = run in daemon mode executing the action file based on events from 853 wpa_supplicant 854 -B = run a daemon in the background 855 default path: /var/run/wpa_supplicant 856 default interface: first interface found in socket path 857 858 859Using wpa_cli to run external program on connect/disconnect 860----------------------------------------------------------- 861 862wpa_cli can used to run external programs whenever wpa_supplicant 863connects or disconnects from a network. This can be used, e.g., to 864update network configuration and/or trigget DHCP client to update IP 865addresses, etc. 866 867One wpa_cli process in "action" mode needs to be started for each 868interface. For example, the following command starts wpa_cli for the 869default ingterface (-i can be used to select the interface in case of 870more than one interface being used at the same time): 871 872wpa_cli -a/sbin/wpa_action.sh -B 873 874The action file (-a option, /sbin/wpa_action.sh in this example) will 875be executed whenever wpa_supplicant completes authentication (connect 876event) or detects disconnection). The action script will be called 877with two command line arguments: interface name and event (CONNECTED 878or DISCONNECTED). If the action script needs to get more information 879about the current network, it can use 'wpa_cli status' to query 880wpa_supplicant for more information. 881 882Following example can be used as a simple template for an action 883script: 884 885#!/bin/sh 886 887IFNAME=$1 888CMD=$2 889 890if [ "$CMD" == "CONNECTED" ]; then 891 SSID=`wpa_cli -i$IFNAME status | grep ^ssid= | cut -f2- -d=` 892 # configure network, signal DHCP client, etc. 893fi 894 895if [ "$CMD" == "DISCONNECTED" ]; then 896 # remove network configuration, if needed 897fi 898 899 900 901Integrating with pcmcia-cs/cardmgr scripts 902------------------------------------------ 903 904wpa_supplicant needs to be running when using a wireless network with 905WPA. It can be started either from system startup scripts or from 906pcmcia-cs/cardmgr scripts (when using PC Cards). WPA handshake must be 907completed before data frames can be exchanged, so wpa_supplicant 908should be started before DHCP client. 909 910For example, following small changes to pcmcia-cs scripts can be used 911to enable WPA support: 912 913Add MODE="Managed" and WPA="y" to the network scheme in 914/etc/pcmcia/wireless.opts. 915 916Add the following block to the end of 'start' action handler in 917/etc/pcmcia/wireless: 918 919 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then 920 /usr/local/bin/wpa_supplicant -B -c/etc/wpa_supplicant.conf \ 921 -i$DEVICE 922 fi 923 924Add the following block to the end of 'stop' action handler (may need 925to be separated from other actions) in /etc/pcmcia/wireless: 926 927 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then 928 killall wpa_supplicant 929 fi 930 931This will make cardmgr start wpa_supplicant when the card is plugged 932in. 933 934 935 936Dynamic interface add and operation without configuration files 937--------------------------------------------------------------- 938 939wpa_supplicant can be started without any configuration files or 940network interfaces. When used in this way, a global (i.e., per 941wpa_supplicant process) control interface is used to add and remove 942network interfaces. Each network interface can then be configured 943through a per-network interface control interface. For example, 944following commands show how to start wpa_supplicant without any 945network interfaces and then add a network interface and configure a 946network (SSID): 947 948# Start wpa_supplicant in the background 949wpa_supplicant -g/var/run/wpa_supplicant-global -B 950 951# Add a new interface (wlan0, no configuration file, driver=wext, and 952# enable control interface) 953wpa_cli -g/var/run/wpa_supplicant-global interface_add wlan0 \ 954 "" wext /var/run/wpa_supplicant 955 956# Configure a network using the newly added network interface: 957wpa_cli -iwlan0 add_network 958wpa_cli -iwlan0 set_network 0 ssid '"test"' 959wpa_cli -iwlan0 set_network 0 key_mgmt WPA-PSK 960wpa_cli -iwlan0 set_network 0 psk '"12345678"' 961wpa_cli -iwlan0 set_network 0 pairwise TKIP 962wpa_cli -iwlan0 set_network 0 group TKIP 963wpa_cli -iwlan0 set_network 0 proto WPA 964wpa_cli -iwlan0 enable_network 0 965 966# At this point, the new network interface should start trying to associate 967# with the WPA-PSK network using SSID test. 968 969# Remove network interface 970wpa_cli -g/var/run/wpa_supplicant-global interface_remove wlan0 971 972 973Privilege separation 974-------------------- 975 976To minimize the size of code that needs to be run with root privileges 977(e.g., to control wireless interface operation), wpa_supplicant 978supports optional privilege separation. If enabled, this separates the 979privileged operations into a separate process (wpa_priv) while leaving 980rest of the code (e.g., EAP authentication and WPA handshakes) into an 981unprivileged process (wpa_supplicant) that can be run as non-root 982user. Privilege separation restricts the effects of potential software 983errors by containing the majority of the code in an unprivileged 984process to avoid full system compromise. 985 986Privilege separation is not enabled by default and it can be enabled 987by adding CONFIG_PRIVSEP=y to the build configuration (.config). When 988enabled, the privileged operations (driver wrapper and l2_packet) are 989linked into a separate daemon program, wpa_priv. The unprivileged 990program, wpa_supplicant, will be built with a special driver/l2_packet 991wrappers that communicate with the privileged wpa_priv process to 992perform the needed operations. wpa_priv can control what privileged 993are allowed. 994 995wpa_priv needs to be run with network admin privileges (usually, root 996user). It opens a UNIX domain socket for each interface that is 997included on the command line; any other interface will be off limits 998for wpa_supplicant in this kind of configuration. After this, 999wpa_supplicant can be run as a non-root user (e.g., all standard users 1000on a laptop or as a special non-privileged user account created just 1001for this purpose to limit access to user files even further). 1002 1003 1004Example configuration: 1005- create user group for users that are allowed to use wpa_supplicant 1006 ('wpapriv' in this example) and assign users that should be able to 1007 use wpa_supplicant into that group 1008- create /var/run/wpa_priv directory for UNIX domain sockets and control 1009 user access by setting it accessible only for the wpapriv group: 1010 mkdir /var/run/wpa_priv 1011 chown root:wpapriv /var/run/wpa_priv 1012 chmod 0750 /var/run/wpa_priv 1013- start wpa_priv as root (e.g., from system startup scripts) with the 1014 enabled interfaces configured on the command line: 1015 wpa_priv -B -P /var/run/wpa_priv.pid wext:ath0 1016- run wpa_supplicant as non-root with a user that is in wpapriv group: 1017 wpa_supplicant -i ath0 -c wpa_supplicant.conf 1018 1019wpa_priv does not use the network interface before wpa_supplicant is 1020started, so it is fine to include network interfaces that are not 1021available at the time wpa_priv is started. As an alternative, wpa_priv 1022can be started when an interface is added (hotplug/udev/etc. scripts). 1023wpa_priv can control multiple interface with one process, but it is 1024also possible to run multiple wpa_priv processes at the same time, if 1025desired. 1026