README revision 8d520ff1dc2da35cdca849e982051b86468016d8
1WPA Supplicant 2============== 3 4Copyright (c) 2003-2011, 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 madwifi driver for cards based on Atheros chip set (ar521x) 151 (http://sourceforge.net/projects/madwifi/) 152 Please note that you will need to modify the wpa_supplicant .config 153 file to use the correct path for the madwifi driver root directory 154 (CFLAGS += -I../madwifi/wpa line in example defconfig). 155 156 Linux ndiswrapper (http://ndiswrapper.sourceforge.net/) with 157 Windows NDIS driver. 158 159 Broadcom wl.o driver (old version only) 160 This is a generic Linux driver for Broadcom IEEE 802.11a/g cards. 161 However, it is proprietary driver that is not publicly available 162 except for couple of exceptions, mainly Broadcom-based APs/wireless 163 routers that use Linux. The driver binary can be downloaded, e.g., 164 from Linksys support site (http://www.linksys.com/support/gpl.asp) 165 for Linksys WRT54G. The GPL tarball includes cross-compiler and 166 the needed header file, wlioctl.h, for compiling wpa_supplicant. 167 This driver support in wpa_supplicant is expected to work also with 168 other devices based on Broadcom driver (assuming the driver includes 169 client mode support). Please note that the newer Broadcom driver 170 ("hybrid Linux driver") supports Linux wireless extensions and does 171 not need (or even work) with the specific driver wrapper. Use -Dwext 172 with that driver. 173 174 In theory, any driver that supports Linux wireless extensions can be 175 used with IEEE 802.1X (i.e., not WPA) when using ap_scan=0 option in 176 configuration file. 177 178 Wired Ethernet drivers (with ap_scan=0) 179 180 BSD net80211 layer (e.g., Atheros driver) 181 At the moment, this is for FreeBSD 6-CURRENT branch and NetBSD-current. 182 183 Windows NDIS 184 The current Windows port requires WinPcap (http://winpcap.polito.it/). 185 See README-Windows.txt for more information. 186 187wpa_supplicant was designed to be portable for different drivers and 188operating systems. Hopefully, support for more wlan cards and OSes will be 189added in the future. See developer's documentation 190(http://hostap.epitest.fi/wpa_supplicant/devel/) for more information about the 191design of wpa_supplicant and porting to other drivers. One main goal 192is to add full WPA/WPA2 support to Linux wireless extensions to allow 193new drivers to be supported without having to implement new 194driver-specific interface code in wpa_supplicant. 195 196Optional libraries for layer2 packet processing: 197- libpcap (tested with 0.7.2, most relatively recent versions assumed to work, 198 this is likely to be available with most distributions, 199 http://tcpdump.org/) 200- libdnet (tested with v1.4, most versions assumed to work, 201 http://libdnet.sourceforge.net/) 202 203These libraries are _not_ used in the default Linux build. Instead, 204internal Linux specific implementation is used. libpcap/libdnet are 205more portable and they can be used by adding CONFIG_L2_PACKET=pcap into 206.config. They may also be selected automatically for other operating 207systems. In case of Windows builds, WinPcap is used by default 208(CONFIG_L2_PACKET=winpcap). 209 210 211Optional libraries for EAP-TLS, EAP-PEAP, and EAP-TTLS: 212- OpenSSL (tested with 0.9.7c and 0.9.7d, and 0.9.8 versions; assumed to 213 work with most relatively recent versions; this is likely to be 214 available with most distributions, http://www.openssl.org/) 215- GnuTLS 216- internal TLSv1 implementation 217 218TLS options for EAP-FAST: 219- OpenSSL 0.9.8d _with_ openssl-0.9.8d-tls-extensions.patch applied 220 (i.e., the default OpenSSL package does not include support for 221 extensions needed for EAP-FAST) 222- internal TLSv1 implementation 223 224One of these libraries is needed when EAP-TLS, EAP-PEAP, EAP-TTLS, or 225EAP-FAST support is enabled. WPA-PSK mode does not require this or EAPOL/EAP 226implementation. A configuration file, .config, for compilation is 227needed to enable IEEE 802.1X/EAPOL and EAP methods. Note that EAP-MD5, 228EAP-GTC, EAP-OTP, and EAP-MSCHAPV2 cannot be used alone with WPA, so 229they should only be enabled if testing the EAPOL/EAP state 230machines. However, there can be used as inner authentication 231algorithms with EAP-PEAP and EAP-TTLS. 232 233See Building and installing section below for more detailed 234information about the wpa_supplicant build time configuration. 235 236 237 238WPA 239--- 240 241The original security mechanism of IEEE 802.11 standard was not 242designed to be strong and has proven to be insufficient for most 243networks that require some kind of security. Task group I (Security) 244of IEEE 802.11 working group (http://www.ieee802.org/11/) has worked 245to address the flaws of the base standard and has in practice 246completed its work in May 2004. The IEEE 802.11i amendment to the IEEE 247802.11 standard was approved in June 2004 and published in July 2004. 248 249Wi-Fi Alliance (http://www.wi-fi.org/) used a draft version of the 250IEEE 802.11i work (draft 3.0) to define a subset of the security 251enhancements that can be implemented with existing wlan hardware. This 252is called Wi-Fi Protected Access<TM> (WPA). This has now become a 253mandatory component of interoperability testing and certification done 254by Wi-Fi Alliance. Wi-Fi provides information about WPA at its web 255site (http://www.wi-fi.org/OpenSection/protected_access.asp). 256 257IEEE 802.11 standard defined wired equivalent privacy (WEP) algorithm 258for protecting wireless networks. WEP uses RC4 with 40-bit keys, 25924-bit initialization vector (IV), and CRC32 to protect against packet 260forgery. All these choices have proven to be insufficient: key space is 261too small against current attacks, RC4 key scheduling is insufficient 262(beginning of the pseudorandom stream should be skipped), IV space is 263too small and IV reuse makes attacks easier, there is no replay 264protection, and non-keyed authentication does not protect against bit 265flipping packet data. 266 267WPA is an intermediate solution for the security issues. It uses 268Temporal Key Integrity Protocol (TKIP) to replace WEP. TKIP is a 269compromise on strong security and possibility to use existing 270hardware. It still uses RC4 for the encryption like WEP, but with 271per-packet RC4 keys. In addition, it implements replay protection, 272keyed packet authentication mechanism (Michael MIC). 273 274Keys can be managed using two different mechanisms. WPA can either use 275an external authentication server (e.g., RADIUS) and EAP just like 276IEEE 802.1X is using or pre-shared keys without need for additional 277servers. Wi-Fi calls these "WPA-Enterprise" and "WPA-Personal", 278respectively. Both mechanisms will generate a master session key for 279the Authenticator (AP) and Supplicant (client station). 280 281WPA implements a new key handshake (4-Way Handshake and Group Key 282Handshake) for generating and exchanging data encryption keys between 283the Authenticator and Supplicant. This handshake is also used to 284verify that both Authenticator and Supplicant know the master session 285key. These handshakes are identical regardless of the selected key 286management mechanism (only the method for generating master session 287key changes). 288 289 290 291IEEE 802.11i / WPA2 292------------------- 293 294The design for parts of IEEE 802.11i that were not included in WPA has 295finished (May 2004) and this amendment to IEEE 802.11 was approved in 296June 2004. Wi-Fi Alliance is using the final IEEE 802.11i as a new 297version of WPA called WPA2. This includes, e.g., support for more 298robust encryption algorithm (CCMP: AES in Counter mode with CBC-MAC) 299to replace TKIP and optimizations for handoff (reduced number of 300messages in initial key handshake, pre-authentication, and PMKSA caching). 301 302 303 304wpa_supplicant 305-------------- 306 307wpa_supplicant is an implementation of the WPA Supplicant component, 308i.e., the part that runs in the client stations. It implements WPA key 309negotiation with a WPA Authenticator and EAP authentication with 310Authentication Server. In addition, it controls the roaming and IEEE 311802.11 authentication/association of the wlan driver. 312 313wpa_supplicant is designed to be a "daemon" program that runs in the 314background and acts as the backend component controlling the wireless 315connection. wpa_supplicant supports separate frontend programs and an 316example text-based frontend, wpa_cli, is included with wpa_supplicant. 317 318Following steps are used when associating with an AP using WPA: 319 320- wpa_supplicant requests the kernel driver to scan neighboring BSSes 321- wpa_supplicant selects a BSS based on its configuration 322- wpa_supplicant requests the kernel driver to associate with the chosen 323 BSS 324- If WPA-EAP: integrated IEEE 802.1X Supplicant completes EAP 325 authentication with the authentication server (proxied by the 326 Authenticator in the AP) 327- If WPA-EAP: master key is received from the IEEE 802.1X Supplicant 328- If WPA-PSK: wpa_supplicant uses PSK as the master session key 329- wpa_supplicant completes WPA 4-Way Handshake and Group Key Handshake 330 with the Authenticator (AP) 331- wpa_supplicant configures encryption keys for unicast and broadcast 332- normal data packets can be transmitted and received 333 334 335 336Building and installing 337----------------------- 338 339In order to be able to build wpa_supplicant, you will first need to 340select which parts of it will be included. This is done by creating a 341build time configuration file, .config, in the wpa_supplicant root 342directory. Configuration options are text lines using following 343format: CONFIG_<option>=y. Lines starting with # are considered 344comments and are ignored. See defconfig file for an example configuration 345and a list of available options and additional notes. 346 347The build time configuration can be used to select only the needed 348features and limit the binary size and requirements for external 349libraries. The main configuration parts are the selection of which 350driver interfaces (e.g., hostap, madwifi, ..) and which authentication 351methods (e.g., EAP-TLS, EAP-PEAP, ..) are included. 352 353Following build time configuration options are used to control IEEE 354802.1X/EAPOL and EAP state machines and all EAP methods. Including 355TLS, PEAP, or TTLS will require linking wpa_supplicant with OpenSSL 356library for TLS implementation. Alternatively, GnuTLS or the internal 357TLSv1 implementation can be used for TLS functionaly. 358 359CONFIG_IEEE8021X_EAPOL=y 360CONFIG_EAP_MD5=y 361CONFIG_EAP_MSCHAPV2=y 362CONFIG_EAP_TLS=y 363CONFIG_EAP_PEAP=y 364CONFIG_EAP_TTLS=y 365CONFIG_EAP_GTC=y 366CONFIG_EAP_OTP=y 367CONFIG_EAP_SIM=y 368CONFIG_EAP_AKA=y 369CONFIG_EAP_PSK=y 370CONFIG_EAP_SAKE=y 371CONFIG_EAP_GPSK=y 372CONFIG_EAP_PAX=y 373CONFIG_EAP_LEAP=y 374CONFIG_EAP_IKEV2=y 375 376Following option can be used to include GSM SIM/USIM interface for GSM/UMTS 377authentication algorithm (for EAP-SIM/EAP-AKA). This requires pcsc-lite 378(http://www.linuxnet.com/) for smart card access. 379 380CONFIG_PCSC=y 381 382Following options can be added to .config to select which driver 383interfaces are included. 384 385CONFIG_DRIVER_HOSTAP=y 386CONFIG_DRIVER_MADWIFI=y 387CONFIG_DRIVER_WEXT=y 388CONFIG_DRIVER_RALINK=y 389CONFIG_DRIVER_BROADCOM=y 390CONFIG_DRIVER_BSD=y 391CONFIG_DRIVER_NDIS=y 392 393Following example includes all features and driver interfaces that are 394included in the wpa_supplicant package: 395 396CONFIG_DRIVER_HOSTAP=y 397CONFIG_DRIVER_MADWIFI=y 398CONFIG_DRIVER_WEXT=y 399CONFIG_DRIVER_BROADCOM=y 400CONFIG_DRIVER_BSD=y 401CONFIG_DRIVER_NDIS=y 402CONFIG_IEEE8021X_EAPOL=y 403CONFIG_EAP_MD5=y 404CONFIG_EAP_MSCHAPV2=y 405CONFIG_EAP_TLS=y 406CONFIG_EAP_PEAP=y 407CONFIG_EAP_TTLS=y 408CONFIG_EAP_GTC=y 409CONFIG_EAP_OTP=y 410CONFIG_EAP_SIM=y 411CONFIG_EAP_AKA=y 412CONFIG_EAP_PSK=y 413CONFIG_EAP_SAKE=y 414CONFIG_EAP_GPSK=y 415CONFIG_EAP_PAX=y 416CONFIG_EAP_LEAP=y 417CONFIG_EAP_IKEV2=y 418CONFIG_PCSC=y 419 420EAP-PEAP and EAP-TTLS will automatically include configured EAP 421methods (MD5, OTP, GTC, MSCHAPV2) for inner authentication selection. 422 423 424After you have created a configuration file, you can build 425wpa_supplicant and wpa_cli with 'make' command. You may then install 426the binaries to a suitable system directory, e.g., /usr/local/bin. 427 428Example commands: 429 430# build wpa_supplicant and wpa_cli 431make 432# install binaries (this may need root privileges) 433cp wpa_cli wpa_supplicant /usr/local/bin 434 435 436You will need to make a configuration file, e.g., 437/etc/wpa_supplicant.conf, with network configuration for the networks 438you are going to use. Configuration file section below includes 439explanation fo the configuration file format and includes various 440examples. Once the configuration is ready, you can test whether the 441configuration work by first running wpa_supplicant with following 442command to start it on foreground with debugging enabled: 443 444wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -d 445 446Assuming everything goes fine, you can start using following command 447to start wpa_supplicant on background without debugging: 448 449wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -B 450 451Please note that if you included more than one driver interface in the 452build time configuration (.config), you may need to specify which 453interface to use by including -D<driver name> option on the command 454line. See following section for more details on command line options 455for wpa_supplicant. 456 457 458 459Command line options 460-------------------- 461 462usage: 463 wpa_supplicant [-BddfhKLqqtuvwW] [-P<pid file>] [-g<global ctrl>] \ 464 -i<ifname> -c<config file> [-C<ctrl>] [-D<driver>] [-p<driver_param>] \ 465 [-b<br_ifname> [-N -i<ifname> -c<conf> [-C<ctrl>] [-D<driver>] \ 466 [-p<driver_param>] [-b<br_ifname>] ...] 467 468options: 469 -b = optional bridge interface name 470 -B = run daemon in the background 471 -c = Configuration file 472 -C = ctrl_interface parameter (only used if -c is not) 473 -i = interface name 474 -d = increase debugging verbosity (-dd even more) 475 -D = driver name (can be multiple drivers: nl80211,wext) 476 -f = Log output to default log location (normally /tmp) 477 -g = global ctrl_interface 478 -K = include keys (passwords, etc.) in debug output 479 -t = include timestamp in debug messages 480 -h = show this help text 481 -L = show license (GPL and BSD) 482 -p = driver parameters 483 -P = PID file 484 -q = decrease debugging verbosity (-qq even less) 485 -u = enable DBus control interface 486 -v = show version 487 -w = wait for interface to be added, if needed 488 -W = wait for a control interface monitor before starting 489 -N = start describing new interface 490 491drivers: 492 hostap = Host AP driver (Intersil Prism2/2.5/3) [default] 493 (this can also be used with Linuxant DriverLoader) 494 madwifi = MADWIFI 802.11 support (Atheros, etc.) (deprecated; use wext) 495 wext = Linux wireless extensions (generic) 496 ralink = Ralink Client driver 497 broadcom = Broadcom wl.o driver 498 wired = wpa_supplicant wired Ethernet driver 499 roboswitch = wpa_supplicant Broadcom switch driver 500 bsd = BSD 802.11 support (Atheros, etc.) 501 ndis = Windows NDIS driver 502 503In most common cases, wpa_supplicant is started with 504 505wpa_supplicant -B -c/etc/wpa_supplicant.conf -iwlan0 506 507This makes the process fork into background. 508 509The easiest way to debug problems, and to get debug log for bug 510reports, is to start wpa_supplicant on foreground with debugging 511enabled: 512 513wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d 514 515If the specific driver wrapper is not known beforehand, it is possible 516to specify multiple comma separated driver wrappers on the command 517line. wpa_supplicant will use the first driver wrapper that is able to 518initialize the interface. 519 520wpa_supplicant -Dnl80211,wext -c/etc/wpa_supplicant.conf -iwlan0 521 522 523wpa_supplicant can control multiple interfaces (radios) either by 524running one process for each interface separately or by running just 525one process and list of options at command line. Each interface is 526separated with -N argument. As an example, following command would 527start wpa_supplicant for two interfaces: 528 529wpa_supplicant \ 530 -c wpa1.conf -i wlan0 -D hostap -N \ 531 -c wpa2.conf -i ath0 -D madwifi 532 533 534If the interface is added in a Linux bridge (e.g., br0), the bridge 535interface needs to be configured to wpa_supplicant in addition to the 536main interface: 537 538wpa_supplicant -cw.conf -Dmadwifi -iath0 -bbr0 539 540 541Configuration file 542------------------ 543 544wpa_supplicant is configured using a text file that lists all accepted 545networks and security policies, including pre-shared keys. See 546example configuration file, wpa_supplicant.conf, for detailed 547information about the configuration format and supported fields. 548 549Changes to configuration file can be reloaded be sending SIGHUP signal 550to wpa_supplicant ('killall -HUP wpa_supplicant'). Similarly, 551reloading can be triggered with 'wpa_cli reconfigure' command. 552 553Configuration file can include one or more network blocks, e.g., one 554for each used SSID. wpa_supplicant will automatically select the best 555betwork based on the order of network blocks in the configuration 556file, network security level (WPA/WPA2 is preferred), and signal 557strength. 558 559Example configuration files for some common configurations: 560 5611) WPA-Personal (PSK) as home network and WPA-Enterprise with EAP-TLS as work 562 network 563 564# allow frontend (e.g., wpa_cli) to be used by all users in 'wheel' group 565ctrl_interface=/var/run/wpa_supplicant 566ctrl_interface_group=wheel 567# 568# home network; allow all valid ciphers 569network={ 570 ssid="home" 571 scan_ssid=1 572 key_mgmt=WPA-PSK 573 psk="very secret passphrase" 574} 575# 576# work network; use EAP-TLS with WPA; allow only CCMP and TKIP ciphers 577network={ 578 ssid="work" 579 scan_ssid=1 580 key_mgmt=WPA-EAP 581 pairwise=CCMP TKIP 582 group=CCMP TKIP 583 eap=TLS 584 identity="user@example.com" 585 ca_cert="/etc/cert/ca.pem" 586 client_cert="/etc/cert/user.pem" 587 private_key="/etc/cert/user.prv" 588 private_key_passwd="password" 589} 590 591 5922) WPA-RADIUS/EAP-PEAP/MSCHAPv2 with RADIUS servers that use old peaplabel 593 (e.g., Funk Odyssey and SBR, Meetinghouse Aegis, Interlink RAD-Series) 594 595ctrl_interface=/var/run/wpa_supplicant 596ctrl_interface_group=wheel 597network={ 598 ssid="example" 599 scan_ssid=1 600 key_mgmt=WPA-EAP 601 eap=PEAP 602 identity="user@example.com" 603 password="foobar" 604 ca_cert="/etc/cert/ca.pem" 605 phase1="peaplabel=0" 606 phase2="auth=MSCHAPV2" 607} 608 609 6103) EAP-TTLS/EAP-MD5-Challenge configuration with anonymous identity for the 611 unencrypted use. Real identity is sent only within an encrypted TLS tunnel. 612 613ctrl_interface=/var/run/wpa_supplicant 614ctrl_interface_group=wheel 615network={ 616 ssid="example" 617 scan_ssid=1 618 key_mgmt=WPA-EAP 619 eap=TTLS 620 identity="user@example.com" 621 anonymous_identity="anonymous@example.com" 622 password="foobar" 623 ca_cert="/etc/cert/ca.pem" 624 phase2="auth=MD5" 625} 626 627 6284) IEEE 802.1X (i.e., no WPA) with dynamic WEP keys (require both unicast and 629 broadcast); use EAP-TLS for authentication 630 631ctrl_interface=/var/run/wpa_supplicant 632ctrl_interface_group=wheel 633network={ 634 ssid="1x-test" 635 scan_ssid=1 636 key_mgmt=IEEE8021X 637 eap=TLS 638 identity="user@example.com" 639 ca_cert="/etc/cert/ca.pem" 640 client_cert="/etc/cert/user.pem" 641 private_key="/etc/cert/user.prv" 642 private_key_passwd="password" 643 eapol_flags=3 644} 645 646 6475) Catch all example that allows more or less all configuration modes. The 648 configuration options are used based on what security policy is used in the 649 selected SSID. This is mostly for testing and is not recommended for normal 650 use. 651 652ctrl_interface=/var/run/wpa_supplicant 653ctrl_interface_group=wheel 654network={ 655 ssid="example" 656 scan_ssid=1 657 key_mgmt=WPA-EAP WPA-PSK IEEE8021X NONE 658 pairwise=CCMP TKIP 659 group=CCMP TKIP WEP104 WEP40 660 psk="very secret passphrase" 661 eap=TTLS PEAP TLS 662 identity="user@example.com" 663 password="foobar" 664 ca_cert="/etc/cert/ca.pem" 665 client_cert="/etc/cert/user.pem" 666 private_key="/etc/cert/user.prv" 667 private_key_passwd="password" 668 phase1="peaplabel=0" 669 ca_cert2="/etc/cert/ca2.pem" 670 client_cert2="/etc/cer/user.pem" 671 private_key2="/etc/cer/user.prv" 672 private_key2_passwd="password" 673} 674 675 6766) Authentication for wired Ethernet. This can be used with 'wired' or 677 'roboswitch' interface (-Dwired or -Droboswitch on command line). 678 679ctrl_interface=/var/run/wpa_supplicant 680ctrl_interface_group=wheel 681ap_scan=0 682network={ 683 key_mgmt=IEEE8021X 684 eap=MD5 685 identity="user" 686 password="password" 687 eapol_flags=0 688} 689 690 691 692Certificates 693------------ 694 695Some EAP authentication methods require use of certificates. EAP-TLS 696uses both server side and client certificates whereas EAP-PEAP and 697EAP-TTLS only require the server side certificate. When client 698certificate is used, a matching private key file has to also be 699included in configuration. If the private key uses a passphrase, this 700has to be configured in wpa_supplicant.conf ("private_key_passwd"). 701 702wpa_supplicant supports X.509 certificates in PEM and DER 703formats. User certificate and private key can be included in the same 704file. 705 706If the user certificate and private key is received in PKCS#12/PFX 707format, they need to be converted to suitable PEM/DER format for 708wpa_supplicant. This can be done, e.g., with following commands: 709 710# convert client certificate and private key to PEM format 711openssl pkcs12 -in example.pfx -out user.pem -clcerts 712# convert CA certificate (if included in PFX file) to PEM format 713openssl pkcs12 -in example.pfx -out ca.pem -cacerts -nokeys 714 715 716 717wpa_cli 718------- 719 720wpa_cli is a text-based frontend program for interacting with 721wpa_supplicant. It is used to query current status, change 722configuration, trigger events, and request interactive user input. 723 724wpa_cli can show the current authentication status, selected security 725mode, dot11 and dot1x MIBs, etc. In addition, it can configure some 726variables like EAPOL state machine parameters and trigger events like 727reassociation and IEEE 802.1X logoff/logon. wpa_cli provides a user 728interface to request authentication information, like username and 729password, if these are not included in the configuration. This can be 730used to implement, e.g., one-time-passwords or generic token card 731authentication where the authentication is based on a 732challenge-response that uses an external device for generating the 733response. 734 735The control interface of wpa_supplicant can be configured to allow 736non-root user access (ctrl_interface_group in the configuration 737file). This makes it possible to run wpa_cli with a normal user 738account. 739 740wpa_cli supports two modes: interactive and command line. Both modes 741share the same command set and the main difference is in interactive 742mode providing access to unsolicited messages (event messages, 743username/password requests). 744 745Interactive mode is started when wpa_cli is executed without including 746the command as a command line parameter. Commands are then entered on 747the wpa_cli prompt. In command line mode, the same commands are 748entered as command line arguments for wpa_cli. 749 750 751Interactive authentication parameters request 752 753When wpa_supplicant need authentication parameters, like username and 754password, which are not present in the configuration file, it sends a 755request message to all attached frontend programs, e.g., wpa_cli in 756interactive mode. wpa_cli shows these requests with 757"CTRL-REQ-<type>-<id>:<text>" prefix. <type> is IDENTITY, PASSWORD, or 758OTP (one-time-password). <id> is a unique identifier for the current 759network. <text> is description of the request. In case of OTP request, 760it includes the challenge from the authentication server. 761 762The reply to these requests can be given with 'identity', 'password', 763and 'otp' commands. <id> needs to be copied from the the matching 764request. 'password' and 'otp' commands can be used regardless of 765whether the request was for PASSWORD or OTP. The main difference 766between these two commands is that values given with 'password' are 767remembered as long as wpa_supplicant is running whereas values given 768with 'otp' are used only once and then forgotten, i.e., wpa_supplicant 769will ask frontend for a new value for every use. This can be used to 770implement one-time-password lists and generic token card -based 771authentication. 772 773Example request for password and a matching reply: 774 775CTRL-REQ-PASSWORD-1:Password needed for SSID foobar 776> password 1 mysecretpassword 777 778Example request for generic token card challenge-response: 779 780CTRL-REQ-OTP-2:Challenge 1235663 needed for SSID foobar 781> otp 2 9876 782 783 784wpa_cli commands 785 786 status = get current WPA/EAPOL/EAP status 787 mib = get MIB variables (dot1x, dot11) 788 help = show this usage help 789 interface [ifname] = show interfaces/select interface 790 level <debug level> = change debug level 791 license = show full wpa_cli license 792 logoff = IEEE 802.1X EAPOL state machine logoff 793 logon = IEEE 802.1X EAPOL state machine logon 794 set = set variables (shows list of variables when run without arguments) 795 pmksa = show PMKSA cache 796 reassociate = force reassociation 797 reconfigure = force wpa_supplicant to re-read its configuration file 798 preauthenticate <BSSID> = force preauthentication 799 identity <network id> <identity> = configure identity for an SSID 800 password <network id> <password> = configure password for an SSID 801 pin <network id> <pin> = configure pin for an SSID 802 otp <network id> <password> = configure one-time-password for an SSID 803 passphrase <network id> <passphrase> = configure private key passphrase 804 for an SSID 805 bssid <network id> <BSSID> = set preferred BSSID for an SSID 806 list_networks = list configured networks 807 select_network <network id> = select a network (disable others) 808 enable_network <network id> = enable a network 809 disable_network <network id> = disable a network 810 add_network = add a network 811 remove_network <network id> = remove a network 812 set_network <network id> <variable> <value> = set network variables (shows 813 list of variables when run without arguments) 814 get_network <network id> <variable> = get network variables 815 save_config = save the current configuration 816 disconnect = disconnect and wait for reassociate command before connecting 817 scan = request new BSS scan 818 scan_results = get latest scan results 819 get_capability <eap/pairwise/group/key_mgmt/proto/auth_alg> = get capabilies 820 terminate = terminate wpa_supplicant 821 quit = exit wpa_cli 822 823 824wpa_cli command line options 825 826wpa_cli [-p<path to ctrl sockets>] [-i<ifname>] [-hvB] [-a<action file>] \ 827 [-P<pid file>] [-g<global ctrl>] [command..] 828 -h = help (show this usage text) 829 -v = shown version information 830 -a = run in daemon mode executing the action file based on events from 831 wpa_supplicant 832 -B = run a daemon in the background 833 default path: /var/run/wpa_supplicant 834 default interface: first interface found in socket path 835 836 837Using wpa_cli to run external program on connect/disconnect 838----------------------------------------------------------- 839 840wpa_cli can used to run external programs whenever wpa_supplicant 841connects or disconnects from a network. This can be used, e.g., to 842update network configuration and/or trigget DHCP client to update IP 843addresses, etc. 844 845One wpa_cli process in "action" mode needs to be started for each 846interface. For example, the following command starts wpa_cli for the 847default ingterface (-i can be used to select the interface in case of 848more than one interface being used at the same time): 849 850wpa_cli -a/sbin/wpa_action.sh -B 851 852The action file (-a option, /sbin/wpa_action.sh in this example) will 853be executed whenever wpa_supplicant completes authentication (connect 854event) or detects disconnection). The action script will be called 855with two command line arguments: interface name and event (CONNECTED 856or DISCONNECTED). If the action script needs to get more information 857about the current network, it can use 'wpa_cli status' to query 858wpa_supplicant for more information. 859 860Following example can be used as a simple template for an action 861script: 862 863#!/bin/sh 864 865IFNAME=$1 866CMD=$2 867 868if [ "$CMD" = "CONNECTED" ]; then 869 SSID=`wpa_cli -i$IFNAME status | grep ^ssid= | cut -f2- -d=` 870 # configure network, signal DHCP client, etc. 871fi 872 873if [ "$CMD" = "DISCONNECTED" ]; then 874 # remove network configuration, if needed 875 SSID= 876fi 877 878 879 880Integrating with pcmcia-cs/cardmgr scripts 881------------------------------------------ 882 883wpa_supplicant needs to be running when using a wireless network with 884WPA. It can be started either from system startup scripts or from 885pcmcia-cs/cardmgr scripts (when using PC Cards). WPA handshake must be 886completed before data frames can be exchanged, so wpa_supplicant 887should be started before DHCP client. 888 889For example, following small changes to pcmcia-cs scripts can be used 890to enable WPA support: 891 892Add MODE="Managed" and WPA="y" to the network scheme in 893/etc/pcmcia/wireless.opts. 894 895Add the following block to the end of 'start' action handler in 896/etc/pcmcia/wireless: 897 898 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then 899 /usr/local/bin/wpa_supplicant -B -c/etc/wpa_supplicant.conf \ 900 -i$DEVICE 901 fi 902 903Add the following block to the end of 'stop' action handler (may need 904to be separated from other actions) in /etc/pcmcia/wireless: 905 906 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then 907 killall wpa_supplicant 908 fi 909 910This will make cardmgr start wpa_supplicant when the card is plugged 911in. 912 913 914 915Dynamic interface add and operation without configuration files 916--------------------------------------------------------------- 917 918wpa_supplicant can be started without any configuration files or 919network interfaces. When used in this way, a global (i.e., per 920wpa_supplicant process) control interface is used to add and remove 921network interfaces. Each network interface can then be configured 922through a per-network interface control interface. For example, 923following commands show how to start wpa_supplicant without any 924network interfaces and then add a network interface and configure a 925network (SSID): 926 927# Start wpa_supplicant in the background 928wpa_supplicant -g/var/run/wpa_supplicant-global -B 929 930# Add a new interface (wlan0, no configuration file, driver=wext, and 931# enable control interface) 932wpa_cli -g/var/run/wpa_supplicant-global interface_add wlan0 \ 933 "" wext /var/run/wpa_supplicant 934 935# Configure a network using the newly added network interface: 936wpa_cli -iwlan0 add_network 937wpa_cli -iwlan0 set_network 0 ssid '"test"' 938wpa_cli -iwlan0 set_network 0 key_mgmt WPA-PSK 939wpa_cli -iwlan0 set_network 0 psk '"12345678"' 940wpa_cli -iwlan0 set_network 0 pairwise TKIP 941wpa_cli -iwlan0 set_network 0 group TKIP 942wpa_cli -iwlan0 set_network 0 proto WPA 943wpa_cli -iwlan0 enable_network 0 944 945# At this point, the new network interface should start trying to associate 946# with the WPA-PSK network using SSID test. 947 948# Remove network interface 949wpa_cli -g/var/run/wpa_supplicant-global interface_remove wlan0 950 951 952Privilege separation 953-------------------- 954 955To minimize the size of code that needs to be run with root privileges 956(e.g., to control wireless interface operation), wpa_supplicant 957supports optional privilege separation. If enabled, this separates the 958privileged operations into a separate process (wpa_priv) while leaving 959rest of the code (e.g., EAP authentication and WPA handshakes) into an 960unprivileged process (wpa_supplicant) that can be run as non-root 961user. Privilege separation restricts the effects of potential software 962errors by containing the majority of the code in an unprivileged 963process to avoid full system compromise. 964 965Privilege separation is not enabled by default and it can be enabled 966by adding CONFIG_PRIVSEP=y to the build configuration (.config). When 967enabled, the privileged operations (driver wrapper and l2_packet) are 968linked into a separate daemon program, wpa_priv. The unprivileged 969program, wpa_supplicant, will be built with a special driver/l2_packet 970wrappers that communicate with the privileged wpa_priv process to 971perform the needed operations. wpa_priv can control what privileged 972are allowed. 973 974wpa_priv needs to be run with network admin privileges (usually, root 975user). It opens a UNIX domain socket for each interface that is 976included on the command line; any other interface will be off limits 977for wpa_supplicant in this kind of configuration. After this, 978wpa_supplicant can be run as a non-root user (e.g., all standard users 979on a laptop or as a special non-privileged user account created just 980for this purpose to limit access to user files even further). 981 982 983Example configuration: 984- create user group for users that are allowed to use wpa_supplicant 985 ('wpapriv' in this example) and assign users that should be able to 986 use wpa_supplicant into that group 987- create /var/run/wpa_priv directory for UNIX domain sockets and control 988 user access by setting it accessible only for the wpapriv group: 989 mkdir /var/run/wpa_priv 990 chown root:wpapriv /var/run/wpa_priv 991 chmod 0750 /var/run/wpa_priv 992- start wpa_priv as root (e.g., from system startup scripts) with the 993 enabled interfaces configured on the command line: 994 wpa_priv -B -P /var/run/wpa_priv.pid wext:ath0 995- run wpa_supplicant as non-root with a user that is in wpapriv group: 996 wpa_supplicant -i ath0 -c wpa_supplicant.conf 997 998wpa_priv does not use the network interface before wpa_supplicant is 999started, so it is fine to include network interfaces that are not 1000available at the time wpa_priv is started. As an alternative, wpa_priv 1001can be started when an interface is added (hotplug/udev/etc. scripts). 1002wpa_priv can control multiple interface with one process, but it is 1003also possible to run multiple wpa_priv processes at the same time, if 1004desired. 1005