WPA Supplicant
==============

Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
All Rights Reserved.

This program is dual-licensed under both the GPL version 2 and BSD
licensed. Either license may be used at your option. Please note that
some of the driver interface implementations (driver_*.c) may be
licensed under a different license.



License
-------

GPL v2:

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

(this copy of the license is in COPYING file)


Alternatively, this software may be distributed under the terms of BSD
license:

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

3. Neither the name(s) of the above-listed copyright holder(s) nor the
   names of its contributors may be used to endorse or promote products
   derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.



Features
--------

Supported WPA/IEEE 802.11i features:
- WPA-PSK ("WPA-Personal")
- WPA with EAP (e.g., with RADIUS authentication server) ("WPA-Enterprise")
  Following authentication methods are supported with an integrate IEEE 802.1X
  Supplicant:
  * EAP-TLS
  * EAP-PEAP/MSCHAPv2 (both PEAPv0 and PEAPv1)
  * EAP-PEAP/TLS (both PEAPv0 and PEAPv1)
  * EAP-PEAP/GTC (both PEAPv0 and PEAPv1)
  * EAP-PEAP/OTP (both PEAPv0 and PEAPv1)
  * EAP-PEAP/MD5-Challenge (both PEAPv0 and PEAPv1)
  * EAP-TTLS/EAP-MD5-Challenge
  * EAP-TTLS/EAP-GTC
  * EAP-TTLS/EAP-OTP
  * EAP-TTLS/EAP-MSCHAPv2
  * EAP-TTLS/EAP-TLS
  * EAP-TTLS/MSCHAPv2
  * EAP-TTLS/MSCHAP
  * EAP-TTLS/PAP
  * EAP-TTLS/CHAP
  * EAP-SIM
  * LEAP (note: only with WEP keys, i.e., not for WPA; in addition, LEAP
	requires special support from the driver for IEEE 802.11
	authentication)
  (following methods are support, but since they do not generate keying
   material, they cannot be used with WPA or IEEE 802.1X WEP keying)
  * EAP-MD5-Challenge 
  * EAP-MSCHAPv2
  * EAP-GTC
  * EAP-OTP
  Alternatively, an external program, e.g., Xsupplicant, can be used for EAP
  authentication.
- key management for CCMP, TKIP, WEP104, WEP40
- RSN/WPA2 (IEEE 802.11i)
  * pre-authentication
  * PMKSA caching



Requirements
------------

Current hardware/software requirements:
- Linux kernel 2.4.x or 2.6.x
- Linux Wireless Extensions v15 or newer
- drivers:
	Host AP driver for Prism2/2.5/3 (development snapshot/v0.2.x)
	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 use the WPA branch and modify
	the wpa_supplicant Makefile to use correct path for madwifi
	driver root directory (CFLAGS += -I../madwifi/wpa line in
	Makefile).

	ATMEL AT76C5XXx driver for USB and PCMCIA cards
	(http://atmelwlandriver.sourceforge.net/).

	Linux ndiswrapper (http://ndiswrapper.sourceforge.net/) with
	Windows NDIS driver.

	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.

wpa_supplicant was designed to be portable for different drivers and
operating systems. Hopefully, support for more wlan cards 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.

Optional libraries for layer2 packet processing:
- libpcap (tested with 0.7.2, most relatively recent versions assumed to work,
	this is likely to be available with most distributions,
	http://tcpdump.org/)
- libdnet (tested with v1.4, most versions assumed to work,
	http://libdnet.sourceforge.net/)

These libraries are _not_ used in the default build. Instead, internal
Linux specific implementation is used. libpcap/libdnet are more
portable and they can be used by modifying Makefile (define
USE_DNET_PCAP and link with these libraries).


Optional libraries for EAP-TLS, EAP-PEAP, and EAP-TTLS:
- openssl (tested with 0.9.7c and 0.9.7d, assumed to work with most
  relatively recent versions; this is likely to be available with most
  distributions, http://www.openssl.org/)

This library is only needed when EAP-TLS, EAP-PEAP, or EAP-TTLS
support is enabled. WPA-PSK mode does not require this or EAPOL/EAP
implementation. A configuration file, .config, for compilation is
needed to enable IEEE 802.1X/EAPOL and EAP methods. Note that EAP-MD5,
EAP-GTC, EAP-OTP, and EAP-MSCHAPV2 cannot be used alone with WPA, so
they should only be enabled if testing the EAPOL/EAP state
machines. However, there can be used as inner authentication
algorithms with EAP-PEAP and EAP-TTLS.

See Building and installing section below for more detailed
information about the wpa_supplicant build time configuration.



WPA
---

The original security mechanism of IEEE 802.11 standard was not
designed to be strong and has proved to be insufficient for most
networks that require some kind of security. Task group I (Security)
of IEEE 802.11 working group (http://www.ieee802.org/11/) has worked
to address the flaws of the base standard and has in practice
completed its work in May 2004. The IEEE 802.11i amendment to the IEEE
802.11 standard was approved in June 2004 and this amendment is likely
to be published in July 2004.

Wi-Fi Alliance (http://www.wi-fi.org/) used a draft version of the
IEEE 802.11i work (draft 3.0) to define a subset of the security
enhancements that can be implemented with existing wlan hardware. This
is called Wi-Fi Protected Access<TM> (WPA). This has now become a
mandatory component of interoperability testing and certification done
by Wi-Fi Alliance. Wi-Fi provides information about WPA at its web
site (http://www.wi-fi.org/OpenSection/protected_access.asp).

IEEE 802.11 standard defined wired equivalent privacy (WEP) algorithm
for protecting wireless networks. WEP uses RC4 with 40-bit keys,
24-bit initialization vector (IV), and CRC32 to protect against packet
forgery. All these choice have proved to be insufficient: key space is
too small against current attacks, RC4 key scheduling is insufficient
(beginning of the pseudorandom stream should be skipped), IV space is
too small and IV reuse makes attacks easier, there is no replay
protection, and non-keyed authentication does not protect against bit
flipping packet data.

WPA is an intermediate solution for the security issues. It uses
temporal key integrity protocol (TKIP) to replace WEP. TKIP is a
compromise on strong security and possibility to use existing
hardware. It still uses RC4 for the encryption like WEP, but with
per-packet RC4 keys. In addition, it implements replay protection,
keyed packet authentication mechanism (Michael MIC).

Keys can be managed using two different mechanisms. WPA can either use
an external authentication server (e.g., RADIUS) and EAP just like
IEEE 802.1X is using or pre-shared keys without need for additional
servers. Wi-Fi calls these "WPA-Enterprise" and "WPA-Personal",
respectively. Both mechanisms will generate a master session key for
the Authenticator (AP) and Supplicant (client station).

WPA implements a new key handshake (4-Way Handshake and Group Key
Handshake) for generating and exchanging data encryption keys between
the Authenticator and Supplicant. This handshake is also used to
verify that both Authenticator and Supplicant know the master session
key. These handshakes are identical regardless of the selected key
management mechanism (only the method for generating master session
key changes).



IEEE 802.11i / WPA2
-------------------

The design for parts of IEEE 802.11i that were not included in WPA has
finished (May 2004) and this amendment to IEEE 802.11 was approved in
June 2004. Wi-Fi Alliance is using the final IEEE 802.11i as a new
version of WPA called WPA2. This includes, e.g., support for more
robust encryption algorithm (CCMP: AES in Counter mode with CBC-MAC)
to replace TKIP and optimizations for handoff (reduced number of
messages in initial key handshake, pre-authentication, key caching).

Some wireless LAN vendors are already providing support for CCMP in
their WPA products. There is no "official" interoperability
certification for CCMP and/or mixed modes using both TKIP and CCMP, so
some interoperability issues can be expected even though many
combinations seem to be working with equipment from different vendors.
Certification for WPA2 is likely to start during the second half of
2004.



wpa_supplicant
--------------

wpa_supplicant 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 wlan driver.

wpa_supplicant is designed to be a "daemon" program that runs in the
background and acts as the backend component controlling the wireless
connection. wpa_supplicant supports separate frontend programs and an
example text-based frontend, wpa_cli, is included with wpa_supplicant.

Following steps are used when associating with an AP using WPA:

- 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)
- If WPA-EAP: master key is received from the IEEE 802.1X Supplicant
- 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



Building and installing
-----------------------

In order to be able to build wpa_supplicant, you will first need to
select which parts of it will be included. This is done by creating a
build time configuration file, .config, in the wpa_supplicant root
directory. Configuration options are text lines using following
format: CONFIG_<option>=y. Lines starting with # are considered
comments and are ignored.

The build time configuration can be used to select only the needed
features and limit the binary size and requirements for external
libraries. The main configuration parts are the selection of which
driver interfaces (e.g., hostap, madwifi, ..) and which authentication
methods (e.g., EAP-TLS, EAP-PEAP, ..) are included.

Following build time configuration options are used to control IEEE
802.1X/EAPOL and EAP state machines and all EAP methods. Including
TLS, PEAP, or TTLS will require linking wpa_supplicant with openssl
library for TLS implementation.

CONFIG_IEEE8021X_EAPOL=y
CONFIG_EAP_MD5=y
CONFIG_MSCHAPV2=y
CONFIG_EAP_TLS=y
CONFIG_EAP_PEAP=y
CONFIG_EAP_TTLS=y
CONFIG_EAP_GTC=y
CONFIG_EAP_OTP=y
CONFIG_EAP_SIM=y
CONFIG_EAP_LEAP=y

Following option can be used to include GSM SIM/USIM interface for GSM
authentication algorithm (for EAP-SIM). This requires pcsc-lite
(http://www.linuxnet.com/) for smart card access.

CONFIG_PCSC=y

Following options can be added to .config to select which driver
interfaces are included. Prism54.org driver is not yet complete and
Hermes driver interface needs to be downloaded from Agere (see above).
Most Linux driver need to include CONFIG_WIRELESS_EXTENSION.

CONFIG_WIRELESS_EXTENSION=y
CONFIG_DRIVER_HOSTAP=y
CONFIG_DRIVER_PRISM54=y
CONFIG_DRIVER_HERMES=y
CONFIG_DRIVER_MADWIFI=y
CONFIG_DRIVER_ATMEL=y
CONFIG_DRIVER_WEXT=y
CONFIG_DRIVER_NDISWRAPPER=y

Following example includes all features and driver interfaces that are
included in the wpa_supplicant package:

CONFIG_DRIVER_HOSTAP=y
CONFIG_DRIVER_PRISM54=y
CONFIG_DRIVER_HERMES=y
CONFIG_DRIVER_MADWIFI=y
CONFIG_DRIVER_ATMEL=y
CONFIG_DRIVER_WEXT=y
CONFIG_DRIVER_NDISWRAPPER=y
CONFIG_WIRELESS_EXTENSION=y
CONFIG_IEEE8021X_EAPOL=y
CONFIG_EAP_MD5=y
CONFIG_MSCHAPV2=y
CONFIG_EAP_TLS=y
CONFIG_EAP_PEAP=y
CONFIG_EAP_TTLS=y
CONFIG_EAP_GTC=y
CONFIG_EAP_OTP=y
CONFIG_EAP_SIM=y
CONFIG_EAP_LEAP=y
CONFIG_PCSC=y

EAP-PEAP and EAP-TTLS will automatically include configured EAP
methods (MD5, OTP, GTC, MSCHAPV2) for inner authentication selection.


After you have created a configuration file, you can build
wpa_supplicant and wpa_cli with 'make' command. You may then install
the binaries to a suitable system directory, e.g., /usr/local/bin.

Example commands:

# build wpa_supplicant and wpa_cli
make
# install binaries (this may need root privileges)
cp wpa_cli wpa_supplicant /usr/local/bin


You will need to make a configuration file, e.g.,
/etc/wpa_supplicant.conf, with network configuration for the networks
you are going to use. Configuration file section below includes
explanation fo the configuration file format and includes various
examples. Once the configuration is ready, you can test whether the
configuration work by first running wpa_supplicant with following
command to start it on foreground with debugging enabled:

wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -d

Assuming everything goes fine, you can start using following command
to start wpa_supplicant on background without debugging:

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. See following section for more details on command line options
for wpa_supplicant.



Command line options
--------------------

usage:
  wpa_supplicant [-BddehLqqvw] -i<ifname> -c<config file> [-D<driver>]

options:
  -B = run daemon in the background
  -d = increase debugging verbosity (-dd even more)
  -e = use external IEEE 802.1X Supplicant (e.g., xsupplicant)
       (this disables the internal Supplicant)
  -h = show this help text
  -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

drivers:
  hostap = Host AP driver (Intersil Prism2/2.5/3) [default]
	(this can also be used with Linuxant DriverLoader)
  prism54 = Prism54.org driver (Intersil Prism GT/Duette/Indigo)
	not yet fully implemented
  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

In most common cases, wpa_supplicant is started with

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.



Configuration file
------------------

wpa_supplicant is configured using a text file that lists all accepted
networks and security policies, including pre-shared keys. See
example configuration file, wpa_supplicant.conf, for detailed
information about the configuration format and supported fields.

Changes to configuration file can be reloaded be sending SIGHUP signal
to wpa_supplicant ('killall -HUP wpa_supplicant'). Similarily,
reloading can be triggered with 'wpa_cli reconfigure' command.

Configuration file can include one or more network blocks, e.g., one
for each used SSID. wpa_supplicant will automatically select the best
betwork based on the order of network blocks in the configuration
file, network security level (WPA/WPA2 is prefered), and signal
strength.

Example configuration files for some common configurations:

1) WPA-Personal (PSK) as home network and WPA-Enterprise with EAP-TLS as work
   network

# allow frontend (e.g., wpa_cli) to be used by all users in 'wheel' group
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel
#
# home network; allow all valid ciphers
network={
	ssid="home"
	scan_ssid=1
	key_mgmt=WPA-PSK
	psk="very secret passphrase"
}
#
# work network; use EAP-TLS with WPA; allow only CCMP and TKIP ciphers
network={
	ssid="work"
	scan_ssid=1
	key_mgmt=WPA-EAP
	pairwise=CCMP TKIP
	group=CCMP TKIP
	eap=TLS
	identity="user@example.com"
	ca_cert="/etc/cert/ca.pem"
	client_cert="/etc/cert/user.pem"
	private_key="/etc/cert/user.prv"
	private_key_passwd="password"
}


2) WPA-RADIUS/EAP-PEAP/MSCHAPv2 with RADIUS servers that use old peaplabel
   (e.g., Funk Odyssey and SBR, Meetinghouse Aegis, Interlink RAD-Series)

ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel
network={
	ssid="example"
	scan_ssid=1
	key_mgmt=WPA-EAP
	eap=PEAP
	identity="user@example.com"
	password="foobar"
	ca_cert="/etc/cert/ca.pem"
	phase1="peaplabel=0"
	phase2="auth=MSCHAPV2"
}


3) EAP-TTLS/EAP-MD5-Challenge configuration with anonymous identity for the
   unencrypted use. Real identity is sent only within an encrypted TLS tunnel.

ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel
network={
	ssid="example"
	scan_ssid=1
	key_mgmt=WPA-EAP
	eap=TTLS
	identity="user@example.com"
	anonymous_identity="anonymous@example.com"
	password="foobar"
	ca_cert="/etc/cert/ca.pem"
	phase2="auth=MD5"
}


4) IEEE 802.1X (i.e., no WPA) with dynamic WEP keys (require both unicast and
   broadcast); use EAP-TLS for authentication

ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel
network={
	ssid="1x-test"
	scan_ssid=1
	key_mgmt=IEEE8021X
	eap=TLS
	identity="user@example.com"
	ca_cert="/etc/cert/ca.pem"
	client_cert="/etc/cert/user.pem"
	private_key="/etc/cert/user.prv"
	private_key_passwd="password"
	eapol_flags=3
}


5) Catch all example that allows more or less all configuration modes. The
   configuration options are used based on what security policy is used in the
   selected SSID. This is mostly for testing and is not recommended for normal
   use.

ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel
network={
	ssid="example"
	scan_ssid=1
	key_mgmt=WPA-EAP WPA-PSK IEEE8021X NONE
	pairwise=CCMP TKIP
	group=CCMP TKIP WEP104 WEP40
	psk="very secret passphrase"
	eap=TTLS PEAP TLS
	identity="user@example.com"
	password="foobar"
	ca_cert="/etc/cert/ca.pem"
	client_cert="/etc/cert/user.pem"
	private_key="/etc/cert/user.prv"
	private_key_passwd="password"
	phase1="peaplabel=0"
	ca_cert2="/etc/cert/ca2.pem"
	client_cert2="/etc/cer/user.pem"
	private_key2="/etc/cer/user.prv"
	private_key2_passwd="password"
}



Certificates
------------

Some EAP authentication methods require use of certificates. EAP-TLS
uses both server side and client certificates whereas EAP-PEAP and
EAP-TTLS only require the server side certificate. When client
certificate is used, a matching private key file has to also be
included in configuration. If the private key uses a passphrase, this
has to be configured in wpa_supplicant.conf ("private_key_passwd").

wpa_supplicant supports X.509 certificates in PEM and DER
formats. User certificate and private key can be included in the same
file.

If the user certificate and private key is received in PKCS#12/PFX
format, they need to be converted to suitable PEM/DER format for
wpa_supplicant. This can be done, e.g., with following commands:

# convert client certificate and private key to PEM format
openssl pkcs12 -in example.pfx -out user.pem -clcerts
# convert CA certificate (if included in PFX file) to PEM format
openssl pkcs12 -in example.pfx -out ca.pem -cacerts -nokeys



wpa_cli
-------

wpa_cli is a text-based frontend program for interacting with
wpa_supplicant. It is used to query current status, change
configuration, trigger events, and request interactive user input.

wpa_cli can show the current authentication status, selected security
mode, dot11 and dot1x MIBs, etc. In addition, it can configuring some
variables like EAPOL state machine parameters and trigger events like
reassociation and IEEE 802.1X logoff/logon. wpa_cli provides a user
interface to request authentication information, like username and
password, if these are not included in the configuration. This can be
used to implement, e.g., one-time-passwords or generic token card
authentication where the authentication is based on a
challenge-response that uses an external device for generating the
response.

The control interface of wpa_supplicant can be configured to allow
non-root user access (ctrl_interface_group in the configuration
file). This makes it possible to run wpa_cli with a normal user
account.

wpa_cli supports two modes: interactive and command line. Both modes
share the same command set and the main difference is in interactive
mode providing access to unsolicited messages (event messages,
username/password requests).

Interactive mode is started when wpa_cli is executed without including
the command as a command line parameter. Commands are then entered on
the wpa_cli prompt. In command line mode, the same commands are
entered as command line arguments for wpa_cli.


Interactive authentication parameters request

When wpa_supplicant need authentication parameters, like username and
password, which are not present in the configuration file, it sends a
request message to all attached frontend programs, e.g., wpa_cli in
interactive mode. wpa_cli shows these requests with
"CTRL-REQ-<type>-<id>:<text>" prefix. <type> is IDENTITY, PASSWORD, or
OTP (one-time-password). <id> is a unique identifier for the current
network. <text> is description of the request. In case of OTP request,
it includes the challenge from the authentication server.

The reply to these requests can be given with 'identity', 'password',
and 'otp' commands. <id> needs to be copied from the the matching
request. 'password' and 'otp' commands can be used regardless of
whether the request was for PASSWORD or OTP. The main difference
between these two commands is that values given with 'password' are
remembered as long as wpa_supplicant is running whereas values given
with 'otp' are used only once and then forgotten, i.e., wpa_supplicant
will ask frontend for a new value for every use. This can be used to
implement one-time-password lists and generic token card -based
authentication.

Example request for password and a matching reply:

CTRL-REQ-PASSWORD-1:Password needed for SSID foobar
> password 1 mysecretpassword

Example request for generic token card challenge-response:

CTRL-REQ-OTP-2:Challenge 1235663 needed for SSID foobar
> otp 2 9876


wpa_cli commands

  status = get current WPA/EAPOL/EAP status
  mib = get MIB variables (dot1x, dot11)
  help = show this usage help
  interface [ifname] = show interfaces/select interface
  level <debug level> = change debug level
  license = show full wpa_cli license
  logoff = IEEE 802.1X EAPOL state machine logoff
  logon = IEEE 802.1X EAPOL state machine logon
  set = set variables (shows list of variables when run without arguments)
  pmksa = show PMKSA cache
  reassociate = force reassociation
  reconfigure = force wpa_supplicant to re-read its configuration file
  preauthenticate <BSSID> = force preauthentication
  identity <network id> <identity> = configure identity for an SSID
  password <network id> <password> = configure password for an SSID
  otp <network id> <password> = configure one-time-password for an SSID
  quit = exit wpa_cli



Integrating with pcmcia-cs/cardmgr scripts
------------------------------------------

wpa_supplicant needs to be running when using a wireless network with
WPA. It can be started either from system startup scripts or from
pcmcia-cs/cardmgr scripts (when using PC Cards). WPA handshake must be
completed before data frames can be exchanged, so wpa_supplicant
should be started before DHCP client.

Command line option '-w' can be used if wpa_supplicant is started
before the wireless LAN interface is present (e.g., before inserting
the PC Card) or is not yet up.

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.

Add the following block to the end of 'start' action handler in
/etc/pcmcia/wireless:

    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 start wpa_supplicant when the card is plugged
in. wpa_supplicant 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.



Optional integration with Xsupplicant
-------------------------------------

wpa_supplicant has an integrated IEEE 802.1X Supplicant that supports
most commonly used EAP methods. In addition, wpa_supplicant has an
experimental interface for integrating it with Xsupplicant
(http://www.open1x.org/) for the WPA with EAP authentication.

Xsupplicant needs to be modified to send master session key to
wpa_supplicant after successful EAP authentication. The included patch
(xsupplicant.patch) shows the changes needed. This was merged into
xsupplicant CVS on February 6, 2004, so any snapshot after that should
have the needed functionality already included.

When using WPA-EAP, both wpa_supplicant and Xsupplicant must be
configured with the network security policy. See Xsupplicant documents
for information about its configuration. Please also note, that a new
command line option -W (enable WPA; added by xsupplicant.patch) must
be used when starting xsupplicant.

Example configuration for xsupplicant:

network_list = all
default_netname = jkm

jkm
{
	type = wireless
	allow_types = eap_peap
	identity = <BEGIN_ID>jkm<END_ID>
	eap-peap {
		random_file = /dev/urandom
		root_cert = /home/jkm/CA.pem
		chunk_size = 1398
		allow_types = eap_mschapv2
		eap-mschapv2 {
			username = <BEGIN_UNAME>jkm<END_UNAME>
			password = <BEGIN_PASS>jkm<END_PASS>
		}
	}
}


Example configuration for wpa_supplicant:

network={
	ssid="jkm"
	key_mgmt=WPA-EAP
}


Both wpa_supplicant and xsupplicant need to be started. Please remember
to add '-W' option for xsupplicant in order to provide keying material
for wpa_supplicant and '-e' option for wpa_supplicant to disable internal
IEEE 802.1X implementation.

wpa_supplicant -iwlan0 -cwpa_supplicant.conf -e
xsupplicant -iwlan0 -cxsupplicant.conf -W
