1WPA Supplicant 2============== 3 4Copyright (c) 2003-2012, Jouni Malinen <j@w1.fi> and contributors 5All Rights Reserved. 6 7This program is licensed under the BSD license (the one with 8advertisement clause removed). 9 10If you are submitting changes to the project, please see CONTRIBUTIONS 11file for more instructions. 12 13 14 15License 16------- 17 18This software may be distributed, used, and modified under the terms of 19BSD license: 20 21Redistribution and use in source and binary forms, with or without 22modification, are permitted provided that the following conditions are 23met: 24 251. Redistributions of source code must retain the above copyright 26 notice, this list of conditions and the following disclaimer. 27 282. Redistributions in binary form must reproduce the above copyright 29 notice, this list of conditions and the following disclaimer in the 30 documentation and/or other materials provided with the distribution. 31 323. Neither the name(s) of the above-listed copyright holder(s) nor the 33 names of its contributors may be used to endorse or promote products 34 derived from this software without specific prior written permission. 35 36THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 37"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 38LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 39A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 40OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 41SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 42LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 43DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 44THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 45(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 46OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 47 48 49 50Features 51-------- 52 53Supported WPA/IEEE 802.11i features: 54- WPA-PSK ("WPA-Personal") 55- WPA with EAP (e.g., with RADIUS authentication server) ("WPA-Enterprise") 56 Following authentication methods are supported with an integrate IEEE 802.1X 57 Supplicant: 58 * EAP-TLS 59 * EAP-PEAP/MSCHAPv2 (both PEAPv0 and PEAPv1) 60 * EAP-PEAP/TLS (both PEAPv0 and PEAPv1) 61 * EAP-PEAP/GTC (both PEAPv0 and PEAPv1) 62 * EAP-PEAP/OTP (both PEAPv0 and PEAPv1) 63 * EAP-PEAP/MD5-Challenge (both PEAPv0 and PEAPv1) 64 * EAP-TTLS/EAP-MD5-Challenge 65 * EAP-TTLS/EAP-GTC 66 * EAP-TTLS/EAP-OTP 67 * EAP-TTLS/EAP-MSCHAPv2 68 * EAP-TTLS/EAP-TLS 69 * EAP-TTLS/MSCHAPv2 70 * EAP-TTLS/MSCHAP 71 * EAP-TTLS/PAP 72 * EAP-TTLS/CHAP 73 * EAP-SIM 74 * EAP-AKA 75 * EAP-PSK 76 * EAP-PAX 77 * EAP-SAKE 78 * EAP-IKEv2 79 * EAP-GPSK 80 * LEAP (note: requires special support from the driver for IEEE 802.11 81 authentication) 82 (following methods are supported, but since they do not generate keying 83 material, they cannot be used with WPA or IEEE 802.1X WEP keying) 84 * EAP-MD5-Challenge 85 * EAP-MSCHAPv2 86 * EAP-GTC 87 * EAP-OTP 88- key management for CCMP, TKIP, WEP104, WEP40 89- RSN/WPA2 (IEEE 802.11i) 90 * pre-authentication 91 * PMKSA caching 92 93Supported TLS/crypto libraries: 94- OpenSSL (default) 95- GnuTLS 96 97Internal TLS/crypto implementation (optional): 98- can be used in place of an external TLS/crypto library 99- TLSv1 100- X.509 certificate processing 101- PKCS #1 102- ASN.1 103- RSA 104- bignum 105- minimal size (ca. 50 kB binary, parts of which are already needed for WPA; 106 TLSv1/X.509/ASN.1/RSA/bignum parts are about 25 kB on x86) 107 108 109Requirements 110------------ 111 112Current hardware/software requirements: 113- Linux kernel 2.4.x or 2.6.x with Linux Wireless Extensions v15 or newer 114- FreeBSD 6-CURRENT 115- NetBSD-current 116- Microsoft Windows with WinPcap (at least WinXP, may work with other versions) 117- drivers: 118 Linux drivers that support WPA/WPA2 configuration with the generic 119 Linux wireless extensions (WE-18 or newer). Even though there are 120 number of driver specific interface included in wpa_supplicant, please 121 note that Linux drivers are moving to use generic wireless extensions 122 and driver_wext (-Dwext on wpa_supplicant command line) should be the 123 default option to start with before falling back to driver specific 124 interface. 125 126 In theory, any driver that supports Linux wireless extensions can be 127 used with IEEE 802.1X (i.e., not WPA) when using ap_scan=0 option in 128 configuration file. 129 130 Wired Ethernet drivers (with ap_scan=0) 131 132 BSD net80211 layer (e.g., Atheros driver) 133 At the moment, this is for FreeBSD 6-CURRENT branch and NetBSD-current. 134 135 Windows NDIS 136 The current Windows port requires WinPcap (http://winpcap.polito.it/). 137 See README-Windows.txt for more information. 138 139wpa_supplicant was designed to be portable for different drivers and 140operating systems. Hopefully, support for more wlan cards and OSes will be 141added in the future. See developer's documentation 142(http://hostap.epitest.fi/wpa_supplicant/devel/) for more information about the 143design of wpa_supplicant and porting to other drivers. One main goal 144is to add full WPA/WPA2 support to Linux wireless extensions to allow 145new drivers to be supported without having to implement new 146driver-specific interface code in wpa_supplicant. 147 148Optional libraries for layer2 packet processing: 149- libpcap (tested with 0.7.2, most relatively recent versions assumed to work, 150 this is likely to be available with most distributions, 151 http://tcpdump.org/) 152- libdnet (tested with v1.4, most versions assumed to work, 153 http://libdnet.sourceforge.net/) 154 155These libraries are _not_ used in the default Linux build. Instead, 156internal Linux specific implementation is used. libpcap/libdnet are 157more portable and they can be used by adding CONFIG_L2_PACKET=pcap into 158.config. They may also be selected automatically for other operating 159systems. In case of Windows builds, WinPcap is used by default 160(CONFIG_L2_PACKET=winpcap). 161 162 163Optional libraries for EAP-TLS, EAP-PEAP, and EAP-TTLS: 164- OpenSSL (tested with 0.9.7c and 0.9.7d, and 0.9.8 versions; assumed to 165 work with most relatively recent versions; this is likely to be 166 available with most distributions, http://www.openssl.org/) 167- GnuTLS 168- internal TLSv1 implementation 169 170TLS options for EAP-FAST: 171- OpenSSL 0.9.8d _with_ openssl-0.9.8d-tls-extensions.patch applied 172 (i.e., the default OpenSSL package does not include support for 173 extensions needed for EAP-FAST) 174- internal TLSv1 implementation 175 176One of these libraries is needed when EAP-TLS, EAP-PEAP, EAP-TTLS, or 177EAP-FAST support is enabled. WPA-PSK mode does not require this or EAPOL/EAP 178implementation. A configuration file, .config, for compilation is 179needed to enable IEEE 802.1X/EAPOL and EAP methods. Note that EAP-MD5, 180EAP-GTC, EAP-OTP, and EAP-MSCHAPV2 cannot be used alone with WPA, so 181they should only be enabled if testing the EAPOL/EAP state 182machines. However, there can be used as inner authentication 183algorithms with EAP-PEAP and EAP-TTLS. 184 185See Building and installing section below for more detailed 186information about the wpa_supplicant build time configuration. 187 188 189 190WPA 191--- 192 193The original security mechanism of IEEE 802.11 standard was not 194designed to be strong and has proven to be insufficient for most 195networks that require some kind of security. Task group I (Security) 196of IEEE 802.11 working group (http://www.ieee802.org/11/) has worked 197to address the flaws of the base standard and has in practice 198completed its work in May 2004. The IEEE 802.11i amendment to the IEEE 199802.11 standard was approved in June 2004 and published in July 2004. 200 201Wi-Fi Alliance (http://www.wi-fi.org/) used a draft version of the 202IEEE 802.11i work (draft 3.0) to define a subset of the security 203enhancements that can be implemented with existing wlan hardware. This 204is called Wi-Fi Protected Access<TM> (WPA). This has now become a 205mandatory component of interoperability testing and certification done 206by Wi-Fi Alliance. Wi-Fi provides information about WPA at its web 207site (http://www.wi-fi.org/OpenSection/protected_access.asp). 208 209IEEE 802.11 standard defined wired equivalent privacy (WEP) algorithm 210for protecting wireless networks. WEP uses RC4 with 40-bit keys, 21124-bit initialization vector (IV), and CRC32 to protect against packet 212forgery. All these choices have proven to be insufficient: key space is 213too small against current attacks, RC4 key scheduling is insufficient 214(beginning of the pseudorandom stream should be skipped), IV space is 215too small and IV reuse makes attacks easier, there is no replay 216protection, and non-keyed authentication does not protect against bit 217flipping packet data. 218 219WPA is an intermediate solution for the security issues. It uses 220Temporal Key Integrity Protocol (TKIP) to replace WEP. TKIP is a 221compromise on strong security and possibility to use existing 222hardware. It still uses RC4 for the encryption like WEP, but with 223per-packet RC4 keys. In addition, it implements replay protection, 224keyed packet authentication mechanism (Michael MIC). 225 226Keys can be managed using two different mechanisms. WPA can either use 227an external authentication server (e.g., RADIUS) and EAP just like 228IEEE 802.1X is using or pre-shared keys without need for additional 229servers. Wi-Fi calls these "WPA-Enterprise" and "WPA-Personal", 230respectively. Both mechanisms will generate a master session key for 231the Authenticator (AP) and Supplicant (client station). 232 233WPA implements a new key handshake (4-Way Handshake and Group Key 234Handshake) for generating and exchanging data encryption keys between 235the Authenticator and Supplicant. This handshake is also used to 236verify that both Authenticator and Supplicant know the master session 237key. These handshakes are identical regardless of the selected key 238management mechanism (only the method for generating master session 239key changes). 240 241 242 243IEEE 802.11i / WPA2 244------------------- 245 246The design for parts of IEEE 802.11i that were not included in WPA has 247finished (May 2004) and this amendment to IEEE 802.11 was approved in 248June 2004. Wi-Fi Alliance is using the final IEEE 802.11i as a new 249version of WPA called WPA2. This includes, e.g., support for more 250robust encryption algorithm (CCMP: AES in Counter mode with CBC-MAC) 251to replace TKIP and optimizations for handoff (reduced number of 252messages in initial key handshake, pre-authentication, and PMKSA caching). 253 254 255 256wpa_supplicant 257-------------- 258 259wpa_supplicant is an implementation of the WPA Supplicant component, 260i.e., the part that runs in the client stations. It implements WPA key 261negotiation with a WPA Authenticator and EAP authentication with 262Authentication Server. In addition, it controls the roaming and IEEE 263802.11 authentication/association of the wlan driver. 264 265wpa_supplicant is designed to be a "daemon" program that runs in the 266background and acts as the backend component controlling the wireless 267connection. wpa_supplicant supports separate frontend programs and an 268example text-based frontend, wpa_cli, is included with wpa_supplicant. 269 270Following steps are used when associating with an AP using WPA: 271 272- wpa_supplicant requests the kernel driver to scan neighboring BSSes 273- wpa_supplicant selects a BSS based on its configuration 274- wpa_supplicant requests the kernel driver to associate with the chosen 275 BSS 276- If WPA-EAP: integrated IEEE 802.1X Supplicant completes EAP 277 authentication with the authentication server (proxied by the 278 Authenticator in the AP) 279- If WPA-EAP: master key is received from the IEEE 802.1X Supplicant 280- If WPA-PSK: wpa_supplicant uses PSK as the master session key 281- wpa_supplicant completes WPA 4-Way Handshake and Group Key Handshake 282 with the Authenticator (AP) 283- wpa_supplicant configures encryption keys for unicast and broadcast 284- normal data packets can be transmitted and received 285 286 287 288Building and installing 289----------------------- 290 291In order to be able to build wpa_supplicant, you will first need to 292select which parts of it will be included. This is done by creating a 293build time configuration file, .config, in the wpa_supplicant root 294directory. Configuration options are text lines using following 295format: CONFIG_<option>=y. Lines starting with # are considered 296comments and are ignored. See defconfig file for an example configuration 297and a list of available options and additional notes. 298 299The build time configuration can be used to select only the needed 300features and limit the binary size and requirements for external 301libraries. The main configuration parts are the selection of which 302driver interfaces (e.g., nl80211, wext, ..) and which authentication 303methods (e.g., EAP-TLS, EAP-PEAP, ..) are included. 304 305Following build time configuration options are used to control IEEE 306802.1X/EAPOL and EAP state machines and all EAP methods. Including 307TLS, PEAP, or TTLS will require linking wpa_supplicant with OpenSSL 308library for TLS implementation. Alternatively, GnuTLS or the internal 309TLSv1 implementation can be used for TLS functionaly. 310 311CONFIG_IEEE8021X_EAPOL=y 312CONFIG_EAP_MD5=y 313CONFIG_EAP_MSCHAPV2=y 314CONFIG_EAP_TLS=y 315CONFIG_EAP_PEAP=y 316CONFIG_EAP_TTLS=y 317CONFIG_EAP_GTC=y 318CONFIG_EAP_OTP=y 319CONFIG_EAP_SIM=y 320CONFIG_EAP_AKA=y 321CONFIG_EAP_PSK=y 322CONFIG_EAP_SAKE=y 323CONFIG_EAP_GPSK=y 324CONFIG_EAP_PAX=y 325CONFIG_EAP_LEAP=y 326CONFIG_EAP_IKEV2=y 327 328Following option can be used to include GSM SIM/USIM interface for GSM/UMTS 329authentication algorithm (for EAP-SIM/EAP-AKA). This requires pcsc-lite 330(http://www.linuxnet.com/) for smart card access. 331 332CONFIG_PCSC=y 333 334Following options can be added to .config to select which driver 335interfaces are included. 336 337CONFIG_DRIVER_NL80211=y 338CONFIG_DRIVER_WEXT=y 339CONFIG_DRIVER_BSD=y 340CONFIG_DRIVER_NDIS=y 341 342Following example includes some more features and driver interfaces that 343are included in the wpa_supplicant package: 344 345CONFIG_DRIVER_NL80211=y 346CONFIG_DRIVER_WEXT=y 347CONFIG_DRIVER_BSD=y 348CONFIG_DRIVER_NDIS=y 349CONFIG_IEEE8021X_EAPOL=y 350CONFIG_EAP_MD5=y 351CONFIG_EAP_MSCHAPV2=y 352CONFIG_EAP_TLS=y 353CONFIG_EAP_PEAP=y 354CONFIG_EAP_TTLS=y 355CONFIG_EAP_GTC=y 356CONFIG_EAP_OTP=y 357CONFIG_EAP_SIM=y 358CONFIG_EAP_AKA=y 359CONFIG_EAP_PSK=y 360CONFIG_EAP_SAKE=y 361CONFIG_EAP_GPSK=y 362CONFIG_EAP_PAX=y 363CONFIG_EAP_LEAP=y 364CONFIG_EAP_IKEV2=y 365CONFIG_PCSC=y 366 367EAP-PEAP and EAP-TTLS will automatically include configured EAP 368methods (MD5, OTP, GTC, MSCHAPV2) for inner authentication selection. 369 370 371After you have created a configuration file, you can build 372wpa_supplicant and wpa_cli with 'make' command. You may then install 373the binaries to a suitable system directory, e.g., /usr/local/bin. 374 375Example commands: 376 377# build wpa_supplicant and wpa_cli 378make 379# install binaries (this may need root privileges) 380cp wpa_cli wpa_supplicant /usr/local/bin 381 382 383You will need to make a configuration file, e.g., 384/etc/wpa_supplicant.conf, with network configuration for the networks 385you are going to use. Configuration file section below includes 386explanation fo the configuration file format and includes various 387examples. Once the configuration is ready, you can test whether the 388configuration work by first running wpa_supplicant with following 389command to start it on foreground with debugging enabled: 390 391wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -d 392 393Assuming everything goes fine, you can start using following command 394to start wpa_supplicant on background without debugging: 395 396wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -B 397 398Please note that if you included more than one driver interface in the 399build time configuration (.config), you may need to specify which 400interface to use by including -D<driver name> option on the command 401line. See following section for more details on command line options 402for wpa_supplicant. 403 404 405 406Command line options 407-------------------- 408 409usage: 410 wpa_supplicant [-BddfhKLqqtuvwW] [-P<pid file>] [-g<global ctrl>] \ 411 -i<ifname> -c<config file> [-C<ctrl>] [-D<driver>] [-p<driver_param>] \ 412 [-b<br_ifname> [-N -i<ifname> -c<conf> [-C<ctrl>] [-D<driver>] \ 413 [-p<driver_param>] [-b<br_ifname>] ...] 414 415options: 416 -b = optional bridge interface name 417 -B = run daemon in the background 418 -c = Configuration file 419 -C = ctrl_interface parameter (only used if -c is not) 420 -i = interface name 421 -d = increase debugging verbosity (-dd even more) 422 -D = driver name (can be multiple drivers: nl80211,wext) 423 -f = Log output to default log location (normally /tmp) 424 -g = global ctrl_interface 425 -K = include keys (passwords, etc.) in debug output 426 -t = include timestamp in debug messages 427 -h = show this help text 428 -L = show license (BSD) 429 -p = driver parameters 430 -P = PID file 431 -q = decrease debugging verbosity (-qq even less) 432 -u = enable DBus control interface 433 -v = show version 434 -w = wait for interface to be added, if needed 435 -W = wait for a control interface monitor before starting 436 -N = start describing new interface 437 438drivers: 439 wext = Linux wireless extensions (generic) 440 wired = wpa_supplicant wired Ethernet driver 441 roboswitch = wpa_supplicant Broadcom switch driver 442 bsd = BSD 802.11 support (Atheros, etc.) 443 ndis = Windows NDIS driver 444 445In most common cases, wpa_supplicant is started with 446 447wpa_supplicant -B -c/etc/wpa_supplicant.conf -iwlan0 448 449This makes the process fork into background. 450 451The easiest way to debug problems, and to get debug log for bug 452reports, is to start wpa_supplicant on foreground with debugging 453enabled: 454 455wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d 456 457If the specific driver wrapper is not known beforehand, it is possible 458to specify multiple comma separated driver wrappers on the command 459line. wpa_supplicant will use the first driver wrapper that is able to 460initialize the interface. 461 462wpa_supplicant -Dnl80211,wext -c/etc/wpa_supplicant.conf -iwlan0 463 464 465wpa_supplicant can control multiple interfaces (radios) either by 466running one process for each interface separately or by running just 467one process and list of options at command line. Each interface is 468separated with -N argument. As an example, following command would 469start wpa_supplicant for two interfaces: 470 471wpa_supplicant \ 472 -c wpa1.conf -i wlan0 -D nl80211 -N \ 473 -c wpa2.conf -i wlan1 -D wext 474 475 476If the interface is added in a Linux bridge (e.g., br0), the bridge 477interface needs to be configured to wpa_supplicant in addition to the 478main interface: 479 480wpa_supplicant -cw.conf -Dwext -iwlan0 -bbr0 481 482 483Configuration file 484------------------ 485 486wpa_supplicant is configured using a text file that lists all accepted 487networks and security policies, including pre-shared keys. See 488example configuration file, wpa_supplicant.conf, for detailed 489information about the configuration format and supported fields. 490 491Changes to configuration file can be reloaded be sending SIGHUP signal 492to wpa_supplicant ('killall -HUP wpa_supplicant'). Similarly, 493reloading can be triggered with 'wpa_cli reconfigure' command. 494 495Configuration file can include one or more network blocks, e.g., one 496for each used SSID. wpa_supplicant will automatically select the best 497betwork based on the order of network blocks in the configuration 498file, network security level (WPA/WPA2 is preferred), and signal 499strength. 500 501Example configuration files for some common configurations: 502 5031) WPA-Personal (PSK) as home network and WPA-Enterprise with EAP-TLS as work 504 network 505 506# allow frontend (e.g., wpa_cli) to be used by all users in 'wheel' group 507ctrl_interface=/var/run/wpa_supplicant 508ctrl_interface_group=wheel 509# 510# home network; allow all valid ciphers 511network={ 512 ssid="home" 513 scan_ssid=1 514 key_mgmt=WPA-PSK 515 psk="very secret passphrase" 516} 517# 518# work network; use EAP-TLS with WPA; allow only CCMP and TKIP ciphers 519network={ 520 ssid="work" 521 scan_ssid=1 522 key_mgmt=WPA-EAP 523 pairwise=CCMP TKIP 524 group=CCMP TKIP 525 eap=TLS 526 identity="user@example.com" 527 ca_cert="/etc/cert/ca.pem" 528 client_cert="/etc/cert/user.pem" 529 private_key="/etc/cert/user.prv" 530 private_key_passwd="password" 531} 532 533 5342) WPA-RADIUS/EAP-PEAP/MSCHAPv2 with RADIUS servers that use old peaplabel 535 (e.g., Funk Odyssey and SBR, Meetinghouse Aegis, Interlink RAD-Series) 536 537ctrl_interface=/var/run/wpa_supplicant 538ctrl_interface_group=wheel 539network={ 540 ssid="example" 541 scan_ssid=1 542 key_mgmt=WPA-EAP 543 eap=PEAP 544 identity="user@example.com" 545 password="foobar" 546 ca_cert="/etc/cert/ca.pem" 547 phase1="peaplabel=0" 548 phase2="auth=MSCHAPV2" 549} 550 551 5523) EAP-TTLS/EAP-MD5-Challenge configuration with anonymous identity for the 553 unencrypted use. Real identity is sent only within an encrypted TLS tunnel. 554 555ctrl_interface=/var/run/wpa_supplicant 556ctrl_interface_group=wheel 557network={ 558 ssid="example" 559 scan_ssid=1 560 key_mgmt=WPA-EAP 561 eap=TTLS 562 identity="user@example.com" 563 anonymous_identity="anonymous@example.com" 564 password="foobar" 565 ca_cert="/etc/cert/ca.pem" 566 phase2="auth=MD5" 567} 568 569 5704) IEEE 802.1X (i.e., no WPA) with dynamic WEP keys (require both unicast and 571 broadcast); use EAP-TLS for authentication 572 573ctrl_interface=/var/run/wpa_supplicant 574ctrl_interface_group=wheel 575network={ 576 ssid="1x-test" 577 scan_ssid=1 578 key_mgmt=IEEE8021X 579 eap=TLS 580 identity="user@example.com" 581 ca_cert="/etc/cert/ca.pem" 582 client_cert="/etc/cert/user.pem" 583 private_key="/etc/cert/user.prv" 584 private_key_passwd="password" 585 eapol_flags=3 586} 587 588 5895) Catch all example that allows more or less all configuration modes. The 590 configuration options are used based on what security policy is used in the 591 selected SSID. This is mostly for testing and is not recommended for normal 592 use. 593 594ctrl_interface=/var/run/wpa_supplicant 595ctrl_interface_group=wheel 596network={ 597 ssid="example" 598 scan_ssid=1 599 key_mgmt=WPA-EAP WPA-PSK IEEE8021X NONE 600 pairwise=CCMP TKIP 601 group=CCMP TKIP WEP104 WEP40 602 psk="very secret passphrase" 603 eap=TTLS PEAP TLS 604 identity="user@example.com" 605 password="foobar" 606 ca_cert="/etc/cert/ca.pem" 607 client_cert="/etc/cert/user.pem" 608 private_key="/etc/cert/user.prv" 609 private_key_passwd="password" 610 phase1="peaplabel=0" 611 ca_cert2="/etc/cert/ca2.pem" 612 client_cert2="/etc/cer/user.pem" 613 private_key2="/etc/cer/user.prv" 614 private_key2_passwd="password" 615} 616 617 6186) Authentication for wired Ethernet. This can be used with 'wired' or 619 'roboswitch' interface (-Dwired or -Droboswitch on command line). 620 621ctrl_interface=/var/run/wpa_supplicant 622ctrl_interface_group=wheel 623ap_scan=0 624network={ 625 key_mgmt=IEEE8021X 626 eap=MD5 627 identity="user" 628 password="password" 629 eapol_flags=0 630} 631 632 633 634Certificates 635------------ 636 637Some EAP authentication methods require use of certificates. EAP-TLS 638uses both server side and client certificates whereas EAP-PEAP and 639EAP-TTLS only require the server side certificate. When client 640certificate is used, a matching private key file has to also be 641included in configuration. If the private key uses a passphrase, this 642has to be configured in wpa_supplicant.conf ("private_key_passwd"). 643 644wpa_supplicant supports X.509 certificates in PEM and DER 645formats. User certificate and private key can be included in the same 646file. 647 648If the user certificate and private key is received in PKCS#12/PFX 649format, they need to be converted to suitable PEM/DER format for 650wpa_supplicant. This can be done, e.g., with following commands: 651 652# convert client certificate and private key to PEM format 653openssl pkcs12 -in example.pfx -out user.pem -clcerts 654# convert CA certificate (if included in PFX file) to PEM format 655openssl pkcs12 -in example.pfx -out ca.pem -cacerts -nokeys 656 657 658 659wpa_cli 660------- 661 662wpa_cli is a text-based frontend program for interacting with 663wpa_supplicant. It is used to query current status, change 664configuration, trigger events, and request interactive user input. 665 666wpa_cli can show the current authentication status, selected security 667mode, dot11 and dot1x MIBs, etc. In addition, it can configure some 668variables like EAPOL state machine parameters and trigger events like 669reassociation and IEEE 802.1X logoff/logon. wpa_cli provides a user 670interface to request authentication information, like username and 671password, if these are not included in the configuration. This can be 672used to implement, e.g., one-time-passwords or generic token card 673authentication where the authentication is based on a 674challenge-response that uses an external device for generating the 675response. 676 677The control interface of wpa_supplicant can be configured to allow 678non-root user access (ctrl_interface_group in the configuration 679file). This makes it possible to run wpa_cli with a normal user 680account. 681 682wpa_cli supports two modes: interactive and command line. Both modes 683share the same command set and the main difference is in interactive 684mode providing access to unsolicited messages (event messages, 685username/password requests). 686 687Interactive mode is started when wpa_cli is executed without including 688the command as a command line parameter. Commands are then entered on 689the wpa_cli prompt. In command line mode, the same commands are 690entered as command line arguments for wpa_cli. 691 692 693Interactive authentication parameters request 694 695When wpa_supplicant need authentication parameters, like username and 696password, which are not present in the configuration file, it sends a 697request message to all attached frontend programs, e.g., wpa_cli in 698interactive mode. wpa_cli shows these requests with 699"CTRL-REQ-<type>-<id>:<text>" prefix. <type> is IDENTITY, PASSWORD, or 700OTP (one-time-password). <id> is a unique identifier for the current 701network. <text> is description of the request. In case of OTP request, 702it includes the challenge from the authentication server. 703 704The reply to these requests can be given with 'identity', 'password', 705and 'otp' commands. <id> needs to be copied from the the matching 706request. 'password' and 'otp' commands can be used regardless of 707whether the request was for PASSWORD or OTP. The main difference 708between these two commands is that values given with 'password' are 709remembered as long as wpa_supplicant is running whereas values given 710with 'otp' are used only once and then forgotten, i.e., wpa_supplicant 711will ask frontend for a new value for every use. This can be used to 712implement one-time-password lists and generic token card -based 713authentication. 714 715Example request for password and a matching reply: 716 717CTRL-REQ-PASSWORD-1:Password needed for SSID foobar 718> password 1 mysecretpassword 719 720Example request for generic token card challenge-response: 721 722CTRL-REQ-OTP-2:Challenge 1235663 needed for SSID foobar 723> otp 2 9876 724 725 726wpa_cli commands 727 728 status = get current WPA/EAPOL/EAP status 729 mib = get MIB variables (dot1x, dot11) 730 help = show this usage help 731 interface [ifname] = show interfaces/select interface 732 level <debug level> = change debug level 733 license = show full wpa_cli license 734 logoff = IEEE 802.1X EAPOL state machine logoff 735 logon = IEEE 802.1X EAPOL state machine logon 736 set = set variables (shows list of variables when run without arguments) 737 pmksa = show PMKSA cache 738 reassociate = force reassociation 739 reconfigure = force wpa_supplicant to re-read its configuration file 740 preauthenticate <BSSID> = force preauthentication 741 identity <network id> <identity> = configure identity for an SSID 742 password <network id> <password> = configure password for an SSID 743 pin <network id> <pin> = configure pin for an SSID 744 otp <network id> <password> = configure one-time-password for an SSID 745 passphrase <network id> <passphrase> = configure private key passphrase 746 for an SSID 747 bssid <network id> <BSSID> = set preferred BSSID for an SSID 748 list_networks = list configured networks 749 select_network <network id> = select a network (disable others) 750 enable_network <network id> = enable a network 751 disable_network <network id> = disable a network 752 add_network = add a network 753 remove_network <network id> = remove a network 754 set_network <network id> <variable> <value> = set network variables (shows 755 list of variables when run without arguments) 756 get_network <network id> <variable> = get network variables 757 save_config = save the current configuration 758 disconnect = disconnect and wait for reassociate command before connecting 759 scan = request new BSS scan 760 scan_results = get latest scan results 761 get_capability <eap/pairwise/group/key_mgmt/proto/auth_alg> = get capabilies 762 terminate = terminate wpa_supplicant 763 quit = exit wpa_cli 764 765 766wpa_cli command line options 767 768wpa_cli [-p<path to ctrl sockets>] [-i<ifname>] [-hvB] [-a<action file>] \ 769 [-P<pid file>] [-g<global ctrl>] [command..] 770 -h = help (show this usage text) 771 -v = shown version information 772 -a = run in daemon mode executing the action file based on events from 773 wpa_supplicant 774 -B = run a daemon in the background 775 default path: /var/run/wpa_supplicant 776 default interface: first interface found in socket path 777 778 779Using wpa_cli to run external program on connect/disconnect 780----------------------------------------------------------- 781 782wpa_cli can used to run external programs whenever wpa_supplicant 783connects or disconnects from a network. This can be used, e.g., to 784update network configuration and/or trigget DHCP client to update IP 785addresses, etc. 786 787One wpa_cli process in "action" mode needs to be started for each 788interface. For example, the following command starts wpa_cli for the 789default ingterface (-i can be used to select the interface in case of 790more than one interface being used at the same time): 791 792wpa_cli -a/sbin/wpa_action.sh -B 793 794The action file (-a option, /sbin/wpa_action.sh in this example) will 795be executed whenever wpa_supplicant completes authentication (connect 796event) or detects disconnection). The action script will be called 797with two command line arguments: interface name and event (CONNECTED 798or DISCONNECTED). If the action script needs to get more information 799about the current network, it can use 'wpa_cli status' to query 800wpa_supplicant for more information. 801 802Following example can be used as a simple template for an action 803script: 804 805#!/bin/sh 806 807IFNAME=$1 808CMD=$2 809 810if [ "$CMD" = "CONNECTED" ]; then 811 SSID=`wpa_cli -i$IFNAME status | grep ^ssid= | cut -f2- -d=` 812 # configure network, signal DHCP client, etc. 813fi 814 815if [ "$CMD" = "DISCONNECTED" ]; then 816 # remove network configuration, if needed 817 SSID= 818fi 819 820 821 822Integrating with pcmcia-cs/cardmgr scripts 823------------------------------------------ 824 825wpa_supplicant needs to be running when using a wireless network with 826WPA. It can be started either from system startup scripts or from 827pcmcia-cs/cardmgr scripts (when using PC Cards). WPA handshake must be 828completed before data frames can be exchanged, so wpa_supplicant 829should be started before DHCP client. 830 831For example, following small changes to pcmcia-cs scripts can be used 832to enable WPA support: 833 834Add MODE="Managed" and WPA="y" to the network scheme in 835/etc/pcmcia/wireless.opts. 836 837Add the following block to the end of 'start' action handler in 838/etc/pcmcia/wireless: 839 840 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then 841 /usr/local/bin/wpa_supplicant -B -c/etc/wpa_supplicant.conf \ 842 -i$DEVICE 843 fi 844 845Add the following block to the end of 'stop' action handler (may need 846to be separated from other actions) in /etc/pcmcia/wireless: 847 848 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then 849 killall wpa_supplicant 850 fi 851 852This will make cardmgr start wpa_supplicant when the card is plugged 853in. 854 855 856 857Dynamic interface add and operation without configuration files 858--------------------------------------------------------------- 859 860wpa_supplicant can be started without any configuration files or 861network interfaces. When used in this way, a global (i.e., per 862wpa_supplicant process) control interface is used to add and remove 863network interfaces. Each network interface can then be configured 864through a per-network interface control interface. For example, 865following commands show how to start wpa_supplicant without any 866network interfaces and then add a network interface and configure a 867network (SSID): 868 869# Start wpa_supplicant in the background 870wpa_supplicant -g/var/run/wpa_supplicant-global -B 871 872# Add a new interface (wlan0, no configuration file, driver=wext, and 873# enable control interface) 874wpa_cli -g/var/run/wpa_supplicant-global interface_add wlan0 \ 875 "" wext /var/run/wpa_supplicant 876 877# Configure a network using the newly added network interface: 878wpa_cli -iwlan0 add_network 879wpa_cli -iwlan0 set_network 0 ssid '"test"' 880wpa_cli -iwlan0 set_network 0 key_mgmt WPA-PSK 881wpa_cli -iwlan0 set_network 0 psk '"12345678"' 882wpa_cli -iwlan0 set_network 0 pairwise TKIP 883wpa_cli -iwlan0 set_network 0 group TKIP 884wpa_cli -iwlan0 set_network 0 proto WPA 885wpa_cli -iwlan0 enable_network 0 886 887# At this point, the new network interface should start trying to associate 888# with the WPA-PSK network using SSID test. 889 890# Remove network interface 891wpa_cli -g/var/run/wpa_supplicant-global interface_remove wlan0 892 893 894Privilege separation 895-------------------- 896 897To minimize the size of code that needs to be run with root privileges 898(e.g., to control wireless interface operation), wpa_supplicant 899supports optional privilege separation. If enabled, this separates the 900privileged operations into a separate process (wpa_priv) while leaving 901rest of the code (e.g., EAP authentication and WPA handshakes) into an 902unprivileged process (wpa_supplicant) that can be run as non-root 903user. Privilege separation restricts the effects of potential software 904errors by containing the majority of the code in an unprivileged 905process to avoid full system compromise. 906 907Privilege separation is not enabled by default and it can be enabled 908by adding CONFIG_PRIVSEP=y to the build configuration (.config). When 909enabled, the privileged operations (driver wrapper and l2_packet) are 910linked into a separate daemon program, wpa_priv. The unprivileged 911program, wpa_supplicant, will be built with a special driver/l2_packet 912wrappers that communicate with the privileged wpa_priv process to 913perform the needed operations. wpa_priv can control what privileged 914are allowed. 915 916wpa_priv needs to be run with network admin privileges (usually, root 917user). It opens a UNIX domain socket for each interface that is 918included on the command line; any other interface will be off limits 919for wpa_supplicant in this kind of configuration. After this, 920wpa_supplicant can be run as a non-root user (e.g., all standard users 921on a laptop or as a special non-privileged user account created just 922for this purpose to limit access to user files even further). 923 924 925Example configuration: 926- create user group for users that are allowed to use wpa_supplicant 927 ('wpapriv' in this example) and assign users that should be able to 928 use wpa_supplicant into that group 929- create /var/run/wpa_priv directory for UNIX domain sockets and control 930 user access by setting it accessible only for the wpapriv group: 931 mkdir /var/run/wpa_priv 932 chown root:wpapriv /var/run/wpa_priv 933 chmod 0750 /var/run/wpa_priv 934- start wpa_priv as root (e.g., from system startup scripts) with the 935 enabled interfaces configured on the command line: 936 wpa_priv -B -P /var/run/wpa_priv.pid wext:ath0 937- run wpa_supplicant as non-root with a user that is in wpapriv group: 938 wpa_supplicant -i ath0 -c wpa_supplicant.conf 939 940wpa_priv does not use the network interface before wpa_supplicant is 941started, so it is fine to include network interfaces that are not 942available at the time wpa_priv is started. As an alternative, wpa_priv 943can be started when an interface is added (hotplug/udev/etc. scripts). 944wpa_priv can control multiple interface with one process, but it is 945also possible to run multiple wpa_priv processes at the same time, if 946desired. 947