- wpa_supplicant - Wi-Fi Protected Access client and IEEE 802.1X supplicant
wpa_supplicant
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- wpa_supplicant
requests the kernel driver to scan neighboring BSSes -
- wpa_supplicant
selects a BSS based on its configuration -
- wpa_supplicant
requests the kernel driver to associate with the chosen BSS -
- If WPA-EAP: integrated IEEE 802.1X Supplicant or external Xsupplicant completes EAP authentication with the authentication server (proxied by the Authenticator in the AP)
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- If WPA-EAP: master key is received from the IEEE 802.1X Supplicant
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- If WPA-PSK: wpa_supplicant
uses PSK as the master session key -
- wpa_supplicant
completes WPA 4-Way Handshake and Group Key Handshake with the Authenticator (AP) -
- wpa_supplicant
configures encryption keys for unicast and broadcast -
- normal data packets can be transmitted and received
Wireless networks do not require physical access to the network equipment in the same way as wired networks. This makes it easier for unauthorized users to passively monitor a network and capture all transmitted frames. In addition, unauthorized use of the network is much easier. In many cases, this can happen even without user's explicit knowledge since the wireless LAN adapter may have been configured to automatically join any available network.
Link-layer encryption can be used to provide a layer of security for wireless networks. The original wireless LAN standard, IEEE 802.11, included a simple encryption mechanism, WEP. However, that proved to be flawed in many areas and network protected with WEP cannot be consider secure. IEEE 802.1X authentication and frequently changed dynamic WEP keys can be used to improve the network security, but even that has inherited security issues due to the use of WEP for encryption. Wi-Fi Protected Access and IEEE 802.11i amendment to the wireless LAN standard introduce a much improvement mechanism for securing wireless networks. IEEE 802.11i enabled networks that are using CCMP (encryption mechanism based on strong cryptographic algorithm AES) can finally be called secure used for applications which require efficient protection against unauthorized access.
wpa_supplicant
After wpa_supplicant
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- WPA-PSK ("WPA-Personal")
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- WPA with EAP (e.g., with RADIUS authentication server) ("WPA-Enterprise") Following authentication methods are supported with an integrate IEEE 802.1X Supplicant:
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- EAP-TLS
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- EAP-PEAP/MSCHAPv2 (both PEAPv0 and PEAPv1)
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- EAP-PEAP/TLS (both PEAPv0 and PEAPv1)
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- EAP-PEAP/GTC (both PEAPv0 and PEAPv1)
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- EAP-PEAP/OTP (both PEAPv0 and PEAPv1)
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- EAP-PEAP/MD5-Challenge (both PEAPv0 and PEAPv1)
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- EAP-TTLS/EAP-MD5-Challenge
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- EAP-TTLS/EAP-GTC
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- EAP-TTLS/EAP-OTP
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- EAP-TTLS/EAP-MSCHAPv2
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- EAP-TTLS/EAP-TLS
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- EAP-TTLS/MSCHAPv2
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- EAP-TTLS/MSCHAP
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- EAP-TTLS/PAP
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- EAP-TTLS/CHAP
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- EAP-SIM
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- EAP-AKA
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- EAP-PSK
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- EAP-PAX
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- LEAP (note: requires special support from the driver for IEEE 802.11 authentication)
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- (following methods are supported, but since they do not generate keying material, they cannot be used with WPA or IEEE 802.1X WEP keying)
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- EAP-MD5-Challenge
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- EAP-MSCHAPv2
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- EAP-GTC
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- EAP-OTP
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- key management for CCMP, TKIP, WEP104, WEP40
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- RSN/WPA2 (IEEE 802.11i)
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- pre-authentication
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- PMKSA caching
Supported WPA/IEEE 802.11i features:
- hostap
- (default) Host AP driver (Intersil Prism2/2.5/3). (this can also be used with Linuxant DriverLoader).
- hermes
- Agere Systems Inc. driver (Hermes-I/Hermes-II).
- madwifi
- MADWIFI 802.11 support (Atheros, etc.).
- atmel
- ATMEL AT76C5XXx (USB, PCMCIA).
- wext
- Linux wireless extensions (generic).
- ndiswrapper
- Linux ndiswrapper.
- broadcom
- Broadcom wl.o driver.
- ipw
- Intel ipw2100/2200 driver.
- wired
- wpa_supplicant wired Ethernet driver
- bsd
- BSD 802.11 support (Atheros, etc.).
- ndis
- Windows NDIS driver.
The available drivers to specify with the -D option are:
- -B
- Run daemon in the background.
- -i ifname
- Interface to listen on.
- -c filename
- Path to configuration file.
- -D driver
- Driver to use. See the available options below.
- -d
- Increase debugging verbosity (-dd even more).
- -K
- Include keys (passwords, etc.) in debug output.
- -t
- Include timestamp in debug messages.
- -e
- Use external IEEE 802.1X Supplicant (e.g., xsupplicant
) (this disables the internal Supplicant). - Use external IEEE 802.1X Supplicant (e.g., xsupplicant
- -h
- Help. Show a usage message.
- -L
- Show license (GPL and BSD).
- -q
- Decrease debugging verbosity (-qq even less).
- -v
- Show version.
- -w
- wait for interface to be added, if needed. normally, wpa_supplicant
will exit if the interface is not there yet. - wait for interface to be added, if needed. normally, wpa_supplicant
- -N
- Start describing new interface.
In most common cases, wpa_supplicant
wpa_supplicant -Bw -c/etc/wpa_supplicant.conf -iwlan0
This makes the process fork into background and wait for the wlan0 interface if it is not available at startup time.
The easiest way to debug problems, and to get debug log for bug reports, is to start wpa_supplicant
wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d
wpa_supplicant
wpa_supplicant \ -c wpa1.conf -i wlan0 -D hostap -N \ -c wpa2.conf -i ath0 -D madwifi
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- Linux kernel 2.4.x or 2.6.x with Linux Wireless Extensions v15 or newer
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- FreeBSD 6-CURRENT
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- Microsoft Windows with WinPcap (at least WinXP, may work with other versions)
Current hardware/software requirements:
- Host AP driver for Prism2/2.5/3 (development snapshot/v0.2.x)
- (http://hostap.epitest.fi/) Driver needs to be set in Managed mode ('iwconfig wlan0 mode managed'). Please note that station firmware version needs to be 1.7.0 or newer to work in WPA mode.
- Linuxant DriverLoader
- (http://www.linuxant.com/driverloader/) with Windows NDIS driver for your wlan card supporting WPA.
- Agere Systems Inc. Linux Driver
- (http://www.agere.com/support/drivers/) Please note that the driver interface file (driver_hermes.c) and hardware specific include files are not included in the wpa_supplicant distribution. You will need to copy these from the source package of the Agere driver.
- madwifi driver for cards based on Atheros chip set (ar521x)
- (http://sourceforge.net/projects/madwifi/) Please note that you will need to modify the wpa_supplicant .config file to use the correct path for the madwifi driver root directory (CFLAGS += -I../madwifi/wpa line in example defconfig).
- ATMEL AT76C5XXx driver for USB and PCMCIA cards
- (http://atmelwlandriver.sourceforge.net/).
- Linux ndiswrapper
- (http://ndiswrapper.sourceforge.net/) with Windows NDIS driver.
- Broadcom wl.o driver
- This is a generic Linux driver for Broadcom IEEE 802.11a/g cards. However, it is proprietary driver that is not publicly available except for couple of exceptions, mainly Broadcom-based APs/wireless routers that use Linux. The driver binary can be downloaded, e.g., from Linksys support site (http://www.linksys.com/support/gpl.asp) for Linksys WRT54G. The GPL tarball includes cross-compiler and the needed header file, wlioctl.h, for compiling wpa_supplicant. This driver support in wpa_supplicant is expected to work also with other devices based on Broadcom driver (assuming the driver includes client mode support).
- Intel ipw2100 driver
- (http://sourceforge.net/projects/ipw2100/)
- Intel ipw2200 driver
- (http://sourceforge.net/projects/ipw2200/)
- Linux wireless extensions
- In theory, any driver that supports Linux wireless extensions can be used with IEEE 802.1X (i.e., not WPA) when using ap_scan=0 option in configuration file.
- Wired Ethernet drivers
- Use ap_scan=0.
- BSD net80211 layer (e.g., Atheros driver)
- At the moment, this is for FreeBSD 6-CURRENT branch.
- Windows NDIS
- The current Windows port requires WinPcap (http://winpcap.polito.it/). See README-Windows.txt for more information.
wpa_supplicant was designed to be portable for different drivers and operating systems. Hopefully, support for more wlan cards and OSes will be added in the future. See developer.txt for more information about the design of wpa_supplicant and porting to other drivers. One main goal is to add full WPA/WPA2 support to Linux wireless extensions to allow new drivers to be supported without having to implement new driver-specific interface code in wpa_supplicant. - The current Windows port requires WinPcap (http://winpcap.polito.it/). See README-Windows.txt for more information.
- wpa_supplicant.conf
- the configuration file describing all networks that the user wants the computer to connect to.
- wpa_supplicant
- the program that directly interacts with the network interface.
- wpa_cli
- the client program that provides a high-level interface to the functionality of the daemon.
- wpa_passphrase
- a utility needed to construct wpa_supplicant.conf
files that include encrypted passwords. - a utility needed to construct wpa_supplicant.conf
The wpa_supplicant
First, make a configuration file, e.g. /etc/wpa_supplicant.conf
wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -d
Assuming everything goes fine, you can start using following command to start wpa_supplicant
wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -B
Please note that if you included more than one driver interface in the build time configuration (.config), you may need to specify which interface to use by including -D<driver name> option on the command line.
For example, following small changes to pcmcia-cs scripts can be used to enable WPA support:
Add MODE="Managed" and WPA="y" to the network scheme in /etc/pcmcia/wireless.opts
if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
/usr/local/bin/wpa_supplicant -Bw -c/etc/wpa_supplicant.conf -i$DEVICE
fi
Add the following block to the end of 'stop' action handler (may need to be separated from other actions) in /etc/pcmcia/wireless
if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
killall wpa_supplicant
fi
This will make cardmgr
wpa_supplicant is copyright (c) 2003-2005, Jouni Malinen <jkmaline@cc.hut.fi> and contributors. All Rights Reserved.
This program is dual-licensed under both the GPL version 2 and BSD license. Either license may be used at your option.