wpa_supplicant.8

VIA无线网卡芯片VT6656的linux驱动源代码

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.\" Please send any bug reports, improvements, comments, patches, 
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.TH "WPA_SUPPLICANT" "8" "06 May 2006" "" ""

.SH NAME
wpa_supplicant \- Wi-Fi Protected Access client and IEEE 802.1X supplicant
.SH SYNOPSIS

\fBwpa_supplicant\fR [ \fB-BddehLqqvw\fR ] [ \fB-i\fIifname\fB\fR ] [ \fB-c\fIconfig file\fB\fR ] [ \fB-D\fIdriver\fB\fR ]

.SH "OVERVIEW"
.PP
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.
.PP
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.
.PP
\fBwpa_supplicant\fR is an implementation of
the WPA Supplicant component, i.e., the part that runs in the
client stations. It implements WPA key negotiation with a WPA
Authenticator and EAP authentication with Authentication
Server. In addition, it controls the roaming and IEEE 802.11
authentication/association of the wireless LAN driver.
.PP
\fBwpa_supplicant\fR is designed to be a
"daemon" program that runs in the background and acts as the
backend component controlling the wireless
connection. \fBwpa_supplicant\fR supports separate
frontend programs and an example text-based frontend,
\fBwpa_cli\fR, is included with
wpa_supplicant.
.PP
Before wpa_supplicant can do its work, the network interface
must be available.  That means that the physical device must be
present and enabled, and the driver for the device must have be
loaded.  Note, however, that the '-w' option of the wpa_supplicant
daemon instructs the daemon to continue running and to wait for
the interface to become available.  Without the '-w' option, the
daemon will exit immediately if the device is not already
available.
.PP
After \fBwpa_supplicant\fR has configured the
network device, higher level configuration such as DHCP may
proceed.  There are a variety of ways to integrate wpa_supplicant
into a machine's networking scripts, a few of which are described
in sections below.
.PP
The following steps are used when associating with an AP
using WPA:
.TP 0.2i
\(bu
\fBwpa_supplicant\fR requests the kernel
driver to scan neighboring BSSes
.TP 0.2i
\(bu
\fBwpa_supplicant\fR selects a BSS based on
its configuration
.TP 0.2i
\(bu
\fBwpa_supplicant\fR requests the kernel
driver to associate with the chosen BSS
.TP 0.2i
\(bu
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)
.TP 0.2i
\(bu
If WPA-EAP: master key is received from the IEEE 802.1X
Supplicant
.TP 0.2i
\(bu
If WPA-PSK: \fBwpa_supplicant\fR uses PSK
as the master session key
.TP 0.2i
\(bu
\fBwpa_supplicant\fR completes WPA 4-Way
Handshake and Group Key Handshake with the Authenticator
(AP)
.TP 0.2i
\(bu
\fBwpa_supplicant\fR configures encryption
keys for unicast and broadcast
.TP 0.2i
\(bu
normal data packets can be transmitted and received
.SH "SUPPORTED FEATURES"
.PP
Supported WPA/IEEE 802.11i features:
.TP 0.2i
\(bu
WPA-PSK ("WPA-Personal")
.TP 0.2i
\(bu
WPA with EAP (e.g., with RADIUS authentication server)
("WPA-Enterprise") Following authentication methods are
supported with an integrate IEEE 802.1X Supplicant:
.RS
.TP 0.2i
\(bu
EAP-TLS
.RE
.RS
.TP 0.2i
\(bu
EAP-PEAP/MSCHAPv2 (both PEAPv0 and PEAPv1)
.TP 0.2i
\(bu
EAP-PEAP/TLS (both PEAPv0 and PEAPv1)
.TP 0.2i
\(bu
EAP-PEAP/GTC (both PEAPv0 and PEAPv1)
.TP 0.2i
\(bu
EAP-PEAP/OTP (both PEAPv0 and PEAPv1)
.TP 0.2i
\(bu
EAP-PEAP/MD5-Challenge (both PEAPv0 and PEAPv1)
.TP 0.2i
\(bu
EAP-TTLS/EAP-MD5-Challenge
.TP 0.2i
\(bu
EAP-TTLS/EAP-GTC
.TP 0.2i
\(bu
EAP-TTLS/EAP-OTP
.TP 0.2i
\(bu
EAP-TTLS/EAP-MSCHAPv2
.TP 0.2i
\(bu
EAP-TTLS/EAP-TLS
.TP 0.2i
\(bu
EAP-TTLS/MSCHAPv2
.TP 0.2i
\(bu
EAP-TTLS/MSCHAP
.TP 0.2i
\(bu
EAP-TTLS/PAP
.TP 0.2i
\(bu
EAP-TTLS/CHAP
.TP 0.2i
\(bu
EAP-SIM
.TP 0.2i
\(bu
EAP-AKA
.TP 0.2i
\(bu
EAP-PSK
.TP 0.2i
\(bu
EAP-PAX
.TP 0.2i
\(bu
LEAP (note: requires special support from
the driver for IEEE 802.11 authentication)
.TP 0.2i
\(bu
(following methods are supported, but since
they do not generate keying material, they cannot be used
with WPA or IEEE 802.1X WEP keying)
.TP 0.2i
\(bu
EAP-MD5-Challenge 
.TP 0.2i
\(bu
EAP-MSCHAPv2
.TP 0.2i
\(bu
EAP-GTC
.TP 0.2i
\(bu
EAP-OTP
.RE
.TP 0.2i
\(bu
key management for CCMP, TKIP, WEP104, WEP40
.TP 0.2i
\(bu
RSN/WPA2 (IEEE 802.11i)
.RS
.TP 0.2i
\(bu
pre-authentication
.TP 0.2i
\(bu
PMKSA caching
.RE
.SH "AVAILABLE DRIVERS"
.PP
The available drivers to specify with the -D option are:
.TP
\fBhostap\fR
(default) Host AP driver (Intersil Prism2/2.5/3).
(this can also be used with Linuxant DriverLoader).
.TP
\fBhermes\fR
Agere Systems Inc. driver (Hermes-I/Hermes-II).
.TP
\fBmadwifi\fR
MADWIFI 802.11 support (Atheros, etc.).
.TP
\fBatmel\fR
ATMEL AT76C5XXx (USB, PCMCIA).
.TP
\fBwext\fR
Linux wireless extensions (generic).
.TP
\fBndiswrapper\fR
Linux ndiswrapper.
.TP
\fBbroadcom\fR
Broadcom wl.o driver.
.TP
\fBipw\fR
Intel ipw2100/2200 driver.
.TP
\fBwired\fR
wpa_supplicant wired Ethernet driver
.TP
\fBbsd\fR
BSD 802.11 support (Atheros, etc.).
.TP
\fBndis\fR
Windows NDIS driver.
.SH "COMMAND LINE OPTIONS"
.TP
\fB-B\fR
Run daemon in the background.
.TP
\fB-i ifname\fR
Interface to listen on.
.TP
\fB-c filename\fR
Path to configuration file.
.TP
\fB-D driver\fR
Driver to use.  See the available options below.
.TP
\fB-d\fR
Increase debugging verbosity (-dd even more).
.TP
\fB-K\fR
Include keys (passwords, etc.) in debug output.
.TP
\fB-t\fR
Include timestamp in debug messages.
.TP
\fB-e\fR
Use external IEEE 802.1X Supplicant (e.g.,
\fBxsupplicant\fR) (this disables the internal
Supplicant).
.TP
\fB-h\fR
Help.  Show a usage message.
.TP
\fB-L\fR
Show license (GPL and BSD).
.TP
\fB-q\fR
Decrease debugging verbosity (-qq even less).
.TP
\fB-v\fR
Show version.
.TP
\fB-w\fR
wait for interface to be added, if needed.  normally,
\fBwpa_supplicant\fR will exit if the interface
is not there yet.
.TP
\fB-N\fR
Start describing new interface.
.SH "EXAMPLES"
.PP
In most common cases, \fBwpa_supplicant\fR is
started with:
.sp
.RS

.nf
wpa_supplicant -Bw -c/etc/wpa_supplicant.conf -iwlan0
.fi
.RE
.PP
This makes the process fork into background and wait for the wlan0
interface if it is not available at startup time.
.PP
The easiest way to debug problems, and to get debug log for
bug reports, is to start \fBwpa_supplicant\fR on
foreground with debugging enabled:
.sp
.RS

.nf
wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d
.fi
.RE
.PP
\fBwpa_supplicant\fR can control multiple
interfaces (radios) either by running one process for each
interface separately or by running just one process and list of
options at command line. Each interface is separated with -N
argument. As an example, following command would start
wpa_supplicant for two interfaces:
.sp
.RS

.nf
wpa_supplicant \\
	-c wpa1.conf -i wlan0 -D hostap -N \\
	-c wpa2.conf -i ath0 -D madwifi
.fi
.RE
.SH "OS REQUIREMENTS"
.PP
Current hardware/software requirements:
.TP 0.2i
\(bu
Linux kernel 2.4.x or 2.6.x with Linux Wireless
Extensions v15 or newer
.TP 0.2i
\(bu
FreeBSD 6-CURRENT
.TP 0.2i
\(bu
Microsoft Windows with WinPcap (at least WinXP, may work
with other versions)
.SH "SUPPORTED DRIVERS"
.TP
\fBHost AP driver for Prism2/2.5/3 (development snapshot/v0.2.x)\fR
(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.
.TP
\fBLinuxant DriverLoader\fR
(http://www.linuxant.com/driverloader/)
with Windows NDIS driver for your wlan card supporting WPA.
.TP
\fBAgere Systems Inc. Linux Driver\fR
(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.
.TP
\fBmadwifi driver for cards based on Atheros chip set (ar521x)\fR
(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).
.TP
\fBATMEL AT76C5XXx driver for USB and PCMCIA cards\fR
(http://atmelwlandriver.sourceforge.net/).
.TP
\fBLinux ndiswrapper\fR
(http://ndiswrapper.sourceforge.net/) with Windows
NDIS driver.
.TP
\fBBroadcom wl.o driver\fR
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).
.TP
\fB Intel ipw2100 driver\fR
(http://sourceforge.net/projects/ipw2100/)
.TP
\fBIntel ipw2200 driver\fR
(http://sourceforge.net/projects/ipw2200/)
.TP
\fBLinux wireless extensions\fR
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.
.TP
\fBWired Ethernet drivers\fR
Use ap_scan=0.
.TP
\fBBSD net80211 layer (e.g., Atheros driver)\fR
At the moment, this is for FreeBSD 6-CURRENT branch.
.TP
\fBWindows NDIS\fR
The current Windows port requires WinPcap
(http://winpcap.polito.it/).  See README-Windows.txt for more
information.
.PP
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.
.SH "ARCHITECTURE"
.PP
The
\fBwpa_supplicant\fR system consists of the following
components:
.TP
\fB\fIwpa_supplicant.conf\fB \fR
the configuration file describing all networks that the
user wants the computer to connect to.  
.TP
\fBwpa_supplicant\fR
the program that directly interacts with the
network interface.  
.TP
\fBwpa_cli\fR
the
client program that provides a high-level interface to the
functionality of the daemon.  
.TP
\fBwpa_passphrase\fR
a utility needed to construct
\fIwpa_supplicant.conf\fR files that include
encrypted passwords.
.SH "QUICK START"
.PP
First, make a configuration file, e.g.
\fI/etc/wpa_supplicant.conf\fR, that describes the networks
you are interested in.  See \fBwpa_supplicant\fR(5)
for details.
.PP
Once the configuration is ready, you can test whether the
configuration works by running \fBwpa_supplicant\fR
with following command to start it on foreground with debugging
enabled:
.sp
.RS

.nf
wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -d
    
.fi
.RE
.PP
Assuming everything goes fine, you can start using following
command to start \fBwpa_supplicant\fR on background
without debugging:
.sp
.RS

.nf
wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -B
    
.fi
.RE
.PP
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.
.SH "INTERFACE TO PCMCIA-CS/CARDMRG"
.PP
For example, following small changes to pcmcia-cs scripts
can be used to enable WPA support:
.PP
Add MODE="Managed" and WPA="y" to the network scheme in
\fI/etc/pcmcia/wireless.opts\fR\&.
.PP
Add the following block to the end of 'start' action handler
in \fI/etc/pcmcia/wireless\fR:
.sp
.RS

.nf
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
    
.fi
.RE
.PP
Add the following block to the end of 'stop' action handler
(may need to be separated from other actions) in
\fI/etc/pcmcia/wireless\fR:
.sp
.RS

.nf
if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
    killall wpa_supplicant
fi
    
.fi
.RE
.PP
This will make \fBcardmgr\fR start
\fBwpa_supplicant\fR when the card is plugged
in. \fBwpa_supplicant\fR will wait until the
interface is set up--either when a static IP address is configured
or when DHCP client is started--and will then negotiate keys with
the AP.
.SH "SEE ALSO"
.PP
\fBwpa_background\fR(8)
\fBwpa_supplicant.conf\fR(5)
\fBwpa_cli\fR(8)
\fBwpa_passphrase\fR(8)
.SH "LEGAL"
.PP
wpa_supplicant is copyright (c) 2003-2005,
Jouni Malinen <[e-mail]> and
contributors.
All Rights Reserved.
.PP
This program is dual-licensed under both the GPL version 2
and BSD license. Either license may be used at your option.