NameDateSize

..23-Apr-20199

ChangeLog22-Aug-201963.8 KiB

config_file.c22-Aug-2019129.2 KiB

config_file.h09-Dec-2018720

ctrl_iface.c22-Aug-2019110.5 KiB

ctrl_iface.h05-Jul-2013998

defconfig22-Aug-201912.9 KiB

eap_register.c22-Aug-20193.2 KiB

eap_register.h05-Jul-2013309

eap_testing.txt06-Nov-20122.5 KiB

hapd_module_tests.c12-Jul-2018364

hlr_auc_gw.c09-Dec-201824 KiB

hlr_auc_gw.milenage_db19-Oct-2015909

hlr_auc_gw.txt05-Jul-20133.2 KiB

hostapd.821-Apr-20151.5 KiB

hostapd.accept06-Nov-2012276

hostapd.conf22-Aug-2019110.9 KiB

hostapd.deny06-Nov-2012144

hostapd.eap_user21-Apr-20154.3 KiB

hostapd.eap_user_sqlite09-Dec-2018909

hostapd.radius_clients06-Nov-2012142

hostapd.sim_db06-Nov-2012409

hostapd.vlan06-Nov-2012282

hostapd.wpa_psk23-Apr-2019834

hostapd_cli.106-Nov-20121.8 KiB

hostapd_cli.c22-Aug-201950.2 KiB

logwatch/06-Nov-20125

main.c22-Aug-201922.3 KiB

nt_password_hash.c05-Jul-2013922

README23-Apr-201915.5 KiB

README-MULTI-AP23-Apr-20198.1 KiB

README-WPS21-Apr-201514 KiB

wired.conf06-Nov-20121.1 KiB

wps-ap-nfc.py23-Apr-20199.8 KiB

README

1hostapd - user space IEEE 802.11 AP and IEEE 802.1X/WPA/WPA2/EAP
2	  Authenticator and RADIUS authentication server
3================================================================
4
5Copyright (c) 2002-2019, Jouni Malinen <j@w1.fi> and contributors
6All Rights Reserved.
7
8This program is licensed under the BSD license (the one with
9advertisement clause removed).
10
11If you are submitting changes to the project, please see CONTRIBUTIONS
12file for more instructions.
13
14
15
16License
17-------
18
19This software may be distributed, used, and modified under the terms of
20BSD license:
21
22Redistribution and use in source and binary forms, with or without
23modification, are permitted provided that the following conditions are
24met:
25
261. Redistributions of source code must retain the above copyright
27   notice, this list of conditions and the following disclaimer.
28
292. Redistributions in binary form must reproduce the above copyright
30   notice, this list of conditions and the following disclaimer in the
31   documentation and/or other materials provided with the distribution.
32
333. Neither the name(s) of the above-listed copyright holder(s) nor the
34   names of its contributors may be used to endorse or promote products
35   derived from this software without specific prior written permission.
36
37THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
38"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
39LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
40A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
41OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
43LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
44DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
45THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
46(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
47OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
48
49
50
51Introduction
52============
53
54Originally, hostapd was an optional user space component for Host AP
55driver. It adds more features to the basic IEEE 802.11 management
56included in the kernel driver: using external RADIUS authentication
57server for MAC address based access control, IEEE 802.1X Authenticator
58and dynamic WEP keying, RADIUS accounting, WPA/WPA2 (IEEE 802.11i/RSN)
59Authenticator and dynamic TKIP/CCMP keying.
60
61The current version includes support for other drivers, an integrated
62EAP server (i.e., allow full authentication without requiring
63an external RADIUS authentication server), and RADIUS authentication
64server for EAP authentication.
65
66
67Requirements
68------------
69
70Current hardware/software requirements:
71- drivers:
72	Host AP driver for Prism2/2.5/3.
73	(http://w1.fi/hostap-driver.html)
74	Please note that station firmware version needs to be 1.7.0 or newer
75	to work in WPA mode.
76
77	mac80211-based drivers that support AP mode (with driver=nl80211).
78	This includes drivers for Atheros (ath9k) and Broadcom (b43)
79	chipsets.
80
81	Any wired Ethernet driver for wired IEEE 802.1X authentication
82	(experimental code)
83
84	FreeBSD -current
85	BSD net80211 layer (e.g., Atheros driver)
86
87
88Build configuration
89-------------------
90
91In order to be able to build hostapd, you will need to create a build
92time configuration file, .config that selects which optional
93components are included. See defconfig file for example configuration
94and list of available options.
95
96
97
98IEEE 802.1X
99===========
100
101IEEE Std 802.1X-2001 is a standard for port-based network access
102control. In case of IEEE 802.11 networks, a "virtual port" is used
103between each associated station and the AP. IEEE 802.11 specifies
104minimal authentication mechanism for stations, whereas IEEE 802.1X
105introduces a extensible mechanism for authenticating and authorizing
106users.
107
108IEEE 802.1X uses elements called Supplicant, Authenticator, Port
109Access Entity, and Authentication Server. Supplicant is a component in
110a station and it performs the authentication with the Authentication
111Server. An access point includes an Authenticator that relays the packets
112between a Supplicant and an Authentication Server. In addition, it has a
113Port Access Entity (PAE) with Authenticator functionality for
114controlling the virtual port authorization, i.e., whether to accept
115packets from or to the station.
116
117IEEE 802.1X uses Extensible Authentication Protocol (EAP). The frames
118between a Supplicant and an Authenticator are sent using EAP over LAN
119(EAPOL) and the Authenticator relays these frames to the Authentication
120Server (and similarly, relays the messages from the Authentication
121Server to the Supplicant). The Authentication Server can be colocated with the
122Authenticator, in which case there is no need for additional protocol
123for EAP frame transmission. However, a more common configuration is to
124use an external Authentication Server and encapsulate EAP frame in the
125frames used by that server. RADIUS is suitable for this, but IEEE
126802.1X would also allow other mechanisms.
127
128Host AP driver includes PAE functionality in the kernel driver. It
129is a relatively simple mechanism for denying normal frames going to
130or coming from an unauthorized port. PAE allows IEEE 802.1X related
131frames to be passed between the Supplicant and the Authenticator even
132on an unauthorized port.
133
134User space daemon, hostapd, includes Authenticator functionality. It
135receives 802.1X (EAPOL) frames from the Supplicant using the wlan#ap
136device that is also used with IEEE 802.11 management frames. The
137frames to the Supplicant are sent using the same device.
138
139The normal configuration of the Authenticator would use an external
140Authentication Server. hostapd supports RADIUS encapsulation of EAP
141packets, so the Authentication Server should be a RADIUS server, like
142FreeRADIUS (http://www.freeradius.org/). The Authenticator in hostapd
143relays the frames between the Supplicant and the Authentication
144Server. It also controls the PAE functionality in the kernel driver by
145controlling virtual port authorization, i.e., station-AP
146connection, based on the IEEE 802.1X state.
147
148When a station would like to use the services of an access point, it
149will first perform IEEE 802.11 authentication. This is normally done
150with open systems authentication, so there is no security. After
151this, IEEE 802.11 association is performed. If IEEE 802.1X is
152configured to be used, the virtual port for the station is set in
153Unauthorized state and only IEEE 802.1X frames are accepted at this
154point. The Authenticator will then ask the Supplicant to authenticate
155with the Authentication Server. After this is completed successfully,
156the virtual port is set to Authorized state and frames from and to the
157station are accepted.
158
159Host AP configuration for IEEE 802.1X
160-------------------------------------
161
162The user space daemon has its own configuration file that can be used to
163define AP options. Distribution package contains an example
164configuration file (hostapd/hostapd.conf) that can be used as a basis
165for configuration. It includes examples of all supported configuration
166options and short description of each option. hostapd should be started
167with full path to the configuration file as the command line argument,
168e.g., './hostapd /etc/hostapd.conf'. If you have more that one wireless
169LAN card, you can use one hostapd process for multiple interfaces by
170giving a list of configuration files (one per interface) in the command
171line.
172
173hostapd includes a minimal co-located IEEE 802.1X server which can be
174used to test IEEE 802.1X authentication. However, it should not be
175used in normal use since it does not provide any security. This can be
176configured by setting ieee8021x and minimal_eap options in the
177configuration file.
178
179An external Authentication Server (RADIUS) is configured with
180auth_server_{addr,port,shared_secret} options. In addition,
181ieee8021x and own_ip_addr must be set for this mode. With such
182configuration, the co-located Authentication Server is not used and EAP
183frames will be relayed using EAPOL between the Supplicant and the
184Authenticator and RADIUS encapsulation between the Authenticator and
185the Authentication Server. Other than this, the functionality is similar
186to the case with the co-located Authentication Server.
187
188Authentication Server
189---------------------
190
191Any RADIUS server supporting EAP should be usable as an IEEE 802.1X
192Authentication Server with hostapd Authenticator. FreeRADIUS
193(http://www.freeradius.org/) has been successfully tested with hostapd
194Authenticator.
195
196Automatic WEP key configuration
197-------------------------------
198
199EAP/TLS generates a session key that can be used to send WEP keys from
200an AP to authenticated stations. The Authenticator in hostapd can be
201configured to automatically select a random default/broadcast key
202(shared by all authenticated stations) with wep_key_len_broadcast
203option (5 for 40-bit WEP or 13 for 104-bit WEP). In addition,
204wep_key_len_unicast option can be used to configure individual unicast
205keys for stations. This requires support for individual keys in the
206station driver.
207
208WEP keys can be automatically updated by configuring rekeying. This
209will improve security of the network since same WEP key will only be
210used for a limited period of time. wep_rekey_period option sets the
211interval for rekeying in seconds.
212
213
214WPA/WPA2
215========
216
217Features
218--------
219
220Supported WPA/IEEE 802.11i features:
221- WPA-PSK ("WPA-Personal")
222- WPA with EAP (e.g., with RADIUS authentication server) ("WPA-Enterprise")
223- key management for CCMP, TKIP, WEP104, WEP40
224- RSN/WPA2 (IEEE 802.11i), including PMKSA caching and pre-authentication
225
226WPA
227---
228
229The original security mechanism of IEEE 802.11 standard was not
230designed to be strong and has proved to be insufficient for most
231networks that require some kind of security. Task group I (Security)
232of IEEE 802.11 working group (http://www.ieee802.org/11/) has worked
233to address the flaws of the base standard and has in practice
234completed its work in May 2004. The IEEE 802.11i amendment to the IEEE
235802.11 standard was approved in June 2004 and this amendment was
236published in July 2004.
237
238Wi-Fi Alliance (http://www.wi-fi.org/) used a draft version of the
239IEEE 802.11i work (draft 3.0) to define a subset of the security
240enhancements that can be implemented with existing wlan hardware. This
241is called Wi-Fi Protected Access<TM> (WPA). This has now become a
242mandatory component of interoperability testing and certification done
243by Wi-Fi Alliance.
244
245IEEE 802.11 standard defined wired equivalent privacy (WEP) algorithm
246for protecting wireless networks. WEP uses RC4 with 40-bit keys,
24724-bit initialization vector (IV), and CRC32 to protect against packet
248forgery. All these choices have proven to be insufficient: key space is
249too small against current attacks, RC4 key scheduling is insufficient
250(beginning of the pseudorandom stream should be skipped), IV space is
251too small and IV reuse makes attacks easier, there is no replay
252protection, and non-keyed authentication does not protect against bit
253flipping packet data.
254
255WPA is an intermediate solution for the security issues. It uses
256Temporal Key Integrity Protocol (TKIP) to replace WEP. TKIP is a
257compromise on strong security and possibility to use existing
258hardware. It still uses RC4 for the encryption like WEP, but with
259per-packet RC4 keys. In addition, it implements replay protection,
260keyed packet authentication mechanism (Michael MIC).
261
262Keys can be managed using two different mechanisms. WPA can either use
263an external authentication server (e.g., RADIUS) and EAP just like
264IEEE 802.1X is using or pre-shared keys without need for additional
265servers. Wi-Fi calls these "WPA-Enterprise" and "WPA-Personal",
266respectively. Both mechanisms will generate a master session key for
267the Authenticator (AP) and Supplicant (client station).
268
269WPA implements a new key handshake (4-Way Handshake and Group Key
270Handshake) for generating and exchanging data encryption keys between
271the Authenticator and Supplicant. This handshake is also used to
272verify that both Authenticator and Supplicant know the master session
273key. These handshakes are identical regardless of the selected key
274management mechanism (only the method for generating master session
275key changes).
276
277
278IEEE 802.11i / WPA2
279-------------------
280
281The design for parts of IEEE 802.11i that were not included in WPA has
282finished (May 2004) and this amendment to IEEE 802.11 was approved in
283June 2004. Wi-Fi Alliance is using the final IEEE 802.11i as a new
284version of WPA called WPA2. This includes, e.g., support for more
285robust encryption algorithm (CCMP: AES in Counter mode with CBC-MAC)
286to replace TKIP and optimizations for handoff (reduced number of
287messages in initial key handshake, pre-authentication, and PMKSA caching).
288
289Some wireless LAN vendors are already providing support for CCMP in
290their WPA products. There is no "official" interoperability
291certification for CCMP and/or mixed modes using both TKIP and CCMP, so
292some interoperability issues can be expected even though many
293combinations seem to be working with equipment from different vendors.
294Testing for WPA2 is likely to start during the second half of 2004.
295
296hostapd configuration for WPA/WPA2
297----------------------------------
298
299TODO
300
301# Enable WPA. Setting this variable configures the AP to require WPA (either
302# WPA-PSK or WPA-RADIUS/EAP based on other configuration). For WPA-PSK, either
303# wpa_psk or wpa_passphrase must be set and wpa_key_mgmt must include WPA-PSK.
304# For WPA-RADIUS/EAP, ieee8021x must be set (but without dynamic WEP keys),
305# RADIUS authentication server must be configured, and WPA-EAP must be included
306# in wpa_key_mgmt.
307# This field is a bit field that can be used to enable WPA (IEEE 802.11i/D3.0)
308# and/or WPA2 (full IEEE 802.11i/RSN):
309# bit0 = WPA
310# bit1 = IEEE 802.11i/RSN (WPA2)
311#wpa=1
312
313# WPA pre-shared keys for WPA-PSK. This can be either entered as a 256-bit
314# secret in hex format (64 hex digits), wpa_psk, or as an ASCII passphrase
315# (8..63 characters) that will be converted to PSK. This conversion uses SSID
316# so the PSK changes when ASCII passphrase is used and the SSID is changed.
317#wpa_psk=0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef
318#wpa_passphrase=secret passphrase
319
320# Set of accepted key management algorithms (WPA-PSK, WPA-EAP, or both). The
321# entries are separated with a space.
322#wpa_key_mgmt=WPA-PSK WPA-EAP
323
324# Set of accepted cipher suites (encryption algorithms) for pairwise keys
325# (unicast packets). This is a space separated list of algorithms:
326# CCMP = AES in Counter mode with CBC-MAC [RFC 3610, IEEE 802.11i]
327# TKIP = Temporal Key Integrity Protocol [IEEE 802.11i]
328# Group cipher suite (encryption algorithm for broadcast and multicast frames)
329# is automatically selected based on this configuration. If only CCMP is
330# allowed as the pairwise cipher, group cipher will also be CCMP. Otherwise,
331# TKIP will be used as the group cipher.
332#wpa_pairwise=TKIP CCMP
333
334# Time interval for rekeying GTK (broadcast/multicast encryption keys) in
335# seconds.
336#wpa_group_rekey=600
337
338# Time interval for rekeying GMK (master key used internally to generate GTKs
339# (in seconds).
340#wpa_gmk_rekey=86400
341
342# Enable IEEE 802.11i/RSN/WPA2 pre-authentication. This is used to speed up
343# roaming be pre-authenticating IEEE 802.1X/EAP part of the full RSN
344# authentication and key handshake before actually associating with a new AP.
345#rsn_preauth=1
346#
347# Space separated list of interfaces from which pre-authentication frames are
348# accepted (e.g., 'eth0' or 'eth0 wlan0wds0'. This list should include all
349# interface that are used for connections to other APs. This could include
350# wired interfaces and WDS links. The normal wireless data interface towards
351# associated stations (e.g., wlan0) should not be added, since
352# pre-authentication is only used with APs other than the currently associated
353# one.
354#rsn_preauth_interfaces=eth0
355

README-MULTI-AP

1hostapd, wpa_supplicant and the Multi-AP Specification
2======================================================
3
4This document describes how hostapd and wpa_supplicant can be configured to
5support the Multi-AP Specification.
6
7Introduction to Multi-AP
8------------------------
9
10The Wi-Fi Alliance Multi-AP Specification is the technical specification for
11Wi-Fi CERTIFIED EasyMesh(TM) [1], the Wi-Fi Alliance�� certification program for
12Multi-AP. It defines control protocols between Wi-Fi�� access points (APs) to
13join them into a network with centralized control and operation. It is targeted
14only at routers (repeaters, gateways, ...), not at clients. Clients are not
15involved at all in the protocols.
16
17Most of the Multi-AP specification falls outside of the scope of
18hostapd/wpa_supplicant. hostapd/wpa_supplicant is only involved for the items
19summarized below. The rest of the protocol must be implemented by a separate
20daemon, e.g., prplMesh [2]. That daemon also needs to communicate with hostapd,
21e.g., to get a list of associated clients, but this can be done using the normal
22hostapd interfaces.
23
24hostapd/wpa_supplicant needs to be configured specifically to support:
25- the WPS onboarding process;
26- configuring backhaul links.
27
28The text below refers to "Multi-AP Specification v1.0" [3].
29
30
31Fronthaul and backhaul links
32----------------------------
33
34In a Multi-AP network, the central controller can configure the BSSs on the
35devices that are joined into the network. These are called fronthaul BSSs.
36From the point of view of hostapd, there is nothing special about these
37fronthaul BSSs.
38
39In addition to fronthaul BSSs, the controller can also configure backhaul
40links. A backhaul link is a link between two access point devices, giving
41internet access to access point devices that don't have a wired link. The
42Multi-AP specification doesn't dictate this, but typically the backhaul link
43will be bridged into a LAN together with (one of) the fronthaul BSS(s) and the
44wired Ethernet ports.
45
46A backhaul link must be treated specially by hostapd and wpa_supplicant. One
47side of the backhaul link is configured through the Multi-AP protocol as the
48"backhaul STA", i.e., the client side of the link. A backhaul STA is like any
49station and is handled appropriately by wpa_supplicant, but two additional
50features are required. It must send an additional information element in each
51(Re)Association Request frame ([3], section 5.2, paragraph 4). In addition, it
52must use 4-address mode for all frames sent over this link ([3], section 14).
53Therefore, wpa_supplicant must be configured explicitly as the backhaul STA
54role, by setting 'multi_ap_backhaul_sta=1' in the network configuration block
55or when configuring the network profile through the control interface. When
56'multi_ap_backhaul_sta=1', wpa_supplicant includes the Multi-AP IE in
57(Re)Association Request frame and verifies that it is included in the
58(Re)Association Response frame. If it is not, association fails. If it is,
59wpa_supplicant sets 4-address mode for this interface through a driver
60callback.
61
62The AP side of the backhaul link is called a "backhaul BSS". Such a BSS must
63be handled specially by hostapd, because it must add an additional information
64element in each (Re)Association Response frame, but only to stations that have
65identified themselves as backhaul stations ([3], section 5.2, paragraph 5-6).
66This is important because it is possible to use the same BSS and SSID for
67fronthaul and backhaul at the same time. The additional information element must
68only be used for frames sent to a backhaul STA, not to a normal STA. Also,
69frames sent to a backhaul STA must use 4-address mode, while frames sent to a
70normal STA (fronthaul, when it's a fronthaul and backhaul BSS) must use
713-address mode.
72
73A BSS is configured in Multi-AP mode in hostapd by setting the 'multi_ap'
74configuration option to 1 (backhaul BSS), 2 (fronthaul BSS), or 3
75(simultaneous backhaul and fronthaul BSS). If this option is set, hostapd
76parses the Multi-AP information element in the Association Request frame. If the
77station is a backhaul STA and the BSS is configured as a backhaul BSS,
78hostapd sets up 4-address mode. Since there may be multiple stations connected
79simultaneously, and each of them has a different RA (receiver address), a VLAN
80is created for each backhaul STA and it is automatically added to a bridge.
81This is the same behavior as for WDS, and the relevant option ('bridge' or
82'wds_bridge') applies here as well.
83
84If 'multi_ap' is 1 (backhaul BSS only), any station that tries to associate
85without the Multi-AP information element will be denied.
86
87If 'multi_ap' is 2 (fronthaul BSS only), any station that tries to associate
88with the Multi-AP information element will be denied. That is also the only
89difference with 'multi_ap' set to 0: in the latter case, the Multi-AP
90information element is simply ignored.
91
92In summary, this is the end-to-end behavior for a backhaul BSS (i.e.,
93multi_ap_backhaul_sta=1 in wpa_supplicant on STA, and multi_ap=1 or 3 in
94hostapd on AP). Note that point 1 means that hostapd must not be configured
95with WPS support on the backhaul BSS (multi_ap=1). hostapd does not check for
96that.
97
981. Backhaul BSS beacons do not advertise WPS support (other than that, nothing
99   Multi-AP specific).
1002. STA sends Authentication frame (nothing Multi-AP specific).
1013. AP sends Authentication frame (nothing Multi-AP specific).
1024. STA sends Association Request frame with Multi-AP IE.
1035. AP sends Association Response frame with Multi-AP IE.
1046. STA and AP both use 4-address mode for Data frames.
105
106
107WPS support
108-----------
109
110WPS requires more special handling. WPS must only be advertised on fronthaul
111BSSs, not on backhaul BSSs, so WPS should not be enabled on a backhaul-only
112BSS in hostapd.conf. The WPS configuration purely works on the fronthaul BSS.
113When a WPS M1 message has an additional subelement that indicates a request for
114a Multi-AP backhaul link, hostapd must not respond with the normal fronthaul
115BSS credentials; instead, it should respond with the (potentially different)
116backhaul BSS credentials.
117
118To support this, hostapd has the 'multi_ap_backhaul_ssid',
119'multi_ap_backhaul_wpa_psk' and 'multi_ap_backhaul_wpa_passphrase' options.
120When these are set on an BSS with WPS, they are used instead of the normal
121credentials when hostapd receives a WPS M1 message with the Multi-AP IE. Only
122WPA2-Personal is supported in the Multi-AP specification, so there is no need
123to specify authentication or encryption options. For the backhaul credentials,
124per-device PSK is not supported.
125
126If the BSS is a simultaneous backhaul and fronthaul BSS, there is no need to
127specify the backhaul credentials, since the backhaul and fronthaul credentials
128are identical.
129
130To enable the Multi-AP backhaul STA feature when it performs WPS, a new
131parameter has been introduced to the WPS_PBC control interface call. When this
132"multi_ap=1" option is set, it adds the Multi-AP backhaul subelement to the
133Association Request frame and the M1 message. It then configures the new network
134profile with 'multi_ap_backhaul_sta=1'. Note that this means that if the AP does
135not follow the Multi-AP specification, wpa_supplicant will fail to associate.
136
137In summary, this is the end-to-end behavior for WPS of a backhaul link (i.e.,
138multi_ap=1 option is given in the wps_pbc call on the STA side, and multi_ap=2
139and multi_ap_backhaul_ssid and either multi_ap_backhaul_wpa_psk or
140multi_ap_backhaul_wpa_passphrase are set to the credentials of a backhaul BSS
141in hostapd on Registrar AP).
142
1431. Fronthaul BSS Beacon frames advertise WPS support (nothing Multi-AP
144   specific).
1452. Enrollee sends Authentication frame (nothing Multi-AP specific).
1463. AP sends Authentication frame (nothing Multi-AP specific).
1474. Enrollee sends Association Request frame with Multi-AP IE.
1485. AP sends Association Response frame with Multi-AP IE.
1496. Enrollee sends M1 with additional Multi-AP subelement.
1507. AP sends M8 with backhaul instead of fronthaul credentials.
1518. Enrollee sends Deauthentication frame.
152
153
154References
155----------
156
157[1] https://www.wi-fi.org/discover-wi-fi/wi-fi-easymesh
158[2] https://github.com/prplfoundation/prplMesh
159[3] https://www.wi-fi.org/file/multi-ap-specification-v10
160    (requires registration)
161

README-WPS

1hostapd and Wi-Fi Protected Setup (WPS)
2=======================================
3
4This document describes how the WPS implementation in hostapd can be
5configured and how an external component on an AP (e.g., web UI) is
6used to enable enrollment of client devices.
7
8
9Introduction to WPS
10-------------------
11
12Wi-Fi Protected Setup (WPS) is a mechanism for easy configuration of a
13wireless network. It allows automated generation of random keys (WPA
14passphrase/PSK) and configuration of an access point and client
15devices. WPS includes number of methods for setting up connections
16with PIN method and push-button configuration (PBC) being the most
17commonly deployed options.
18
19While WPS can enable more home networks to use encryption in the
20wireless network, it should be noted that the use of the PIN and
21especially PBC mechanisms for authenticating the initial key setup is
22not very secure. As such, use of WPS may not be suitable for
23environments that require secure network access without chance for
24allowing outsiders to gain access during the setup phase.
25
26WPS uses following terms to describe the entities participating in the
27network setup:
28- access point: the WLAN access point
29- Registrar: a device that control a network and can authorize
30  addition of new devices); this may be either in the AP ("internal
31  Registrar") or in an external device, e.g., a laptop, ("external
32  Registrar")
33- Enrollee: a device that is being authorized to use the network
34
35It should also be noted that the AP and a client device may change
36roles (i.e., AP acts as an Enrollee and client device as a Registrar)
37when WPS is used to configure the access point.
38
39
40More information about WPS is available from Wi-Fi Alliance:
41http://www.wi-fi.org/wifi-protected-setup
42
43
44hostapd implementation
45----------------------
46
47hostapd includes an optional WPS component that can be used as an
48internal WPS Registrar to manage addition of new WPS enabled clients
49to the network. In addition, WPS Enrollee functionality in hostapd can
50be used to allow external WPS Registrars to configure the access
51point, e.g., for initial network setup. In addition, hostapd can proxy a
52WPS registration between a wireless Enrollee and an external Registrar
53(e.g., Microsoft Vista or Atheros JumpStart) with UPnP.
54
55
56hostapd configuration
57---------------------
58
59WPS is an optional component that needs to be enabled in hostapd build
60configuration (.config). Here is an example configuration that
61includes WPS support and uses nl80211 driver interface:
62
63CONFIG_DRIVER_NL80211=y
64CONFIG_WPS=y
65CONFIG_WPS_UPNP=y
66
67Following parameter can be used to enable support for NFC config method:
68
69CONFIG_WPS_NFC=y
70
71
72Following section shows an example runtime configuration
73(hostapd.conf) that enables WPS:
74
75# Configure the driver and network interface
76driver=nl80211
77interface=wlan0
78
79# WPA2-Personal configuration for the AP
80ssid=wps-test
81wpa=2
82wpa_key_mgmt=WPA-PSK
83wpa_pairwise=CCMP
84# Default WPA passphrase for legacy (non-WPS) clients
85wpa_passphrase=12345678
86# Enable random per-device PSK generation for WPS clients
87# Please note that the file has to exists for hostapd to start (i.e., create an
88# empty file as a starting point).
89wpa_psk_file=/etc/hostapd.psk
90
91# Enable control interface for PBC/PIN entry
92ctrl_interface=/var/run/hostapd
93
94# Enable internal EAP server for EAP-WSC (part of Wi-Fi Protected Setup)
95eap_server=1
96
97# WPS configuration (AP configured, do not allow external WPS Registrars)
98wps_state=2
99ap_setup_locked=1
100# If UUID is not configured, it will be generated based on local MAC address.
101uuid=87654321-9abc-def0-1234-56789abc0000
102wps_pin_requests=/var/run/hostapd.pin-req
103device_name=Wireless AP
104manufacturer=Company
105model_name=WAP
106model_number=123
107serial_number=12345
108device_type=6-0050F204-1
109os_version=01020300
110config_methods=label display push_button keypad
111
112# if external Registrars are allowed, UPnP support could be added:
113#upnp_iface=br0
114#friendly_name=WPS Access Point
115
116
117External operations
118-------------------
119
120WPS requires either a device PIN code (usually, 8-digit number) or a
121pushbutton event (for PBC) to allow a new WPS Enrollee to join the
122network. hostapd uses the control interface as an input channel for
123these events.
124
125The PIN value used in the commands must be processed by an UI to
126remove non-digit characters and potentially, to verify the checksum
127digit. "hostapd_cli wps_check_pin <PIN>" can be used to do such
128processing. It returns FAIL if the PIN is invalid, or FAIL-CHECKSUM if
129the checksum digit is incorrect, or the processed PIN (non-digit
130characters removed) if the PIN is valid.
131
132When a client device (WPS Enrollee) connects to hostapd (WPS
133Registrar) in order to start PIN mode negotiation for WPS, an
134identifier (Enrollee UUID) is sent. hostapd will need to be configured
135with a device password (PIN) for this Enrollee. This is an operation
136that requires user interaction (assuming there are no pre-configured
137PINs on the AP for a set of Enrollee).
138
139The PIN request with information about the device is appended to the
140wps_pin_requests file (/var/run/hostapd.pin-req in this example). In
141addition, hostapd control interface event is sent as a notification of
142a new device. The AP could use, e.g., a web UI for showing active
143Enrollees to the user and request a PIN for an Enrollee.
144
145The PIN request file has one line for every Enrollee that connected to
146the AP, but for which there was no PIN. Following information is
147provided for each Enrollee (separated with tabulators):
148- timestamp (seconds from 1970-01-01)
149- Enrollee UUID
150- MAC address
151- Device name
152- Manufacturer
153- Model Name
154- Model Number
155- Serial Number
156- Device category
157
158Example line in the /var/run/hostapd.pin-req file:
1591200188391	53b63a98-d29e-4457-a2ed-094d7e6a669c	Intel(R) Centrino(R)	Intel Corporation	Intel(R) Centrino(R)	-	-	1-0050F204-1
160
161Control interface data:
162WPS-PIN-NEEDED [UUID-E|MAC Address|Device Name|Manufacturer|Model Name|Model Number|Serial Number|Device Category]
163For example:
164<2>WPS-PIN-NEEDED [53b63a98-d29e-4457-a2ed-094d7e6a669c|02:12:34:56:78:9a|Device|Manuf|Model|Model Number|Serial Number|1-0050F204-1]
165
166When the user enters a PIN for a pending Enrollee, e.g., on the web
167UI), hostapd needs to be notified of the new PIN over the control
168interface. This can be done either by using the UNIX domain socket
169-based control interface directly (src/common/wpa_ctrl.c provides
170helper functions for using the interface) or by calling hostapd_cli.
171
172Example command to add a PIN (12345670) for an Enrollee:
173
174hostapd_cli wps_pin 53b63a98-d29e-4457-a2ed-094d7e6a669c 12345670
175
176If the UUID-E is not available (e.g., Enrollee waits for the Registrar
177to be selected before connecting), wildcard UUID may be used to allow
178the PIN to be used once with any UUID:
179
180hostapd_cli wps_pin any 12345670
181
182To reduce likelihood of PIN being used with other devices or of
183forgetting an active PIN available for potential attackers, expiration
184time in seconds can be set for the new PIN (value 0 indicates no
185expiration):
186
187hostapd_cli wps_pin any 12345670 300
188
189If the MAC address of the enrollee is known, it should be configured
190to allow the AP to advertise list of authorized enrollees:
191
192hostapd_cli wps_pin 53b63a98-d29e-4457-a2ed-094d7e6a669c \
193	12345670 300 00:11:22:33:44:55
194
195
196After this, the Enrollee can connect to the AP again and complete WPS
197negotiation. At that point, a new, random WPA PSK is generated for the
198client device and the client can then use that key to connect to the
199AP to access the network.
200
201
202If the AP includes a pushbutton, WPS PBC mode can be used. It is
203enabled by pushing a button on both the AP and the client at about the
204same time (2 minute window). hostapd needs to be notified about the AP
205button pushed event over the control interface, e.g., by calling
206hostapd_cli:
207
208hostapd_cli wps_pbc
209
210At this point, the client has two minutes to complete WPS negotiation
211which will generate a new WPA PSK in the same way as the PIN method
212described above.
213
214
215When an external Registrar is used, the AP can act as an Enrollee and
216use its AP PIN. A static AP PIN (e.g., one one a label in the AP
217device) can be configured in hostapd.conf (ap_pin parameter). A more
218secure option is to use hostapd_cli wps_ap_pin command to enable the
219AP PIN only based on user action (and even better security by using a
220random AP PIN for each session, i.e., by using "wps_ap_pin random"
221command with a timeout value). Following commands are available for
222managing the dynamic AP PIN operations:
223
224hostapd_cli wps_ap_pin disable
225- disable AP PIN (i.e., do not allow external Registrars to use it to
226  learn the current AP settings or to reconfigure the AP)
227
228hostapd_cli wps_ap_pin random [timeout]
229- generate a random AP PIN and enable it
230- if the optional timeout parameter is given, the AP PIN will be enabled
231  for the specified number of seconds
232
233hostapd_cli wps_ap_pin get
234- fetch the current AP PIN
235
236hostapd_cli wps_ap_pin set <PIN> [timeout]
237- set the AP PIN and enable it
238- if the optional timeout parameter is given, the AP PIN will be enabled
239  for the specified number of seconds
240
241hostapd_cli get_config
242- display the current configuration
243
244hostapd_cli wps_config <new SSID> <auth> <encr> <new key>
245examples:
246  hostapd_cli wps_config testing WPA2PSK CCMP 12345678
247  hostapd_cli wps_config "no security" OPEN NONE ""
248
249<auth> must be one of the following: OPEN WPAPSK WPA2PSK
250<encr> must be one of the following: NONE WEP TKIP CCMP
251
252
253Credential generation and configuration changes
254-----------------------------------------------
255
256By default, hostapd generates credentials for Enrollees and processing
257AP configuration updates internally. However, it is possible to
258control these operations from external programs, if desired.
259
260The internal credential generation can be disabled with
261skip_cred_build=1 option in the configuration. extra_cred option will
262then need to be used to provide pre-configured Credential attribute(s)
263for hostapd to use. The exact data from this binary file will be sent,
264i.e., it will have to include valid WPS attributes. extra_cred can
265also be used to add additional networks if the Registrar is used to
266configure credentials for multiple networks.
267
268Processing of received configuration updates can be disabled with
269wps_cred_processing=1 option. When this is used, an external program
270is responsible for creating hostapd configuration files and processing
271configuration updates based on messages received from hostapd over
272control interface. This will also include the initial configuration on
273first successful registration if the AP is initially set in
274unconfigured state.
275
276Following control interface messages are sent out for external programs:
277
278WPS-REG-SUCCESS <Enrollee MAC address <UUID-E>
279For example:
280<2>WPS-REG-SUCCESS 02:66:a0:ee:17:27 2b7093f1-d6fb-5108-adbb-bea66bb87333
281
282This can be used to trigger change from unconfigured to configured
283state (random configuration based on the first successful WPS
284registration). In addition, this can be used to update AP UI about the
285status of WPS registration progress.
286
287
288WPS-NEW-AP-SETTINGS <hexdump of AP Setup attributes>
289For example:
290<2>WPS-NEW-AP-SETTINGS 10260001011045000c6a6b6d2d7770732d74657374100300020020100f00020008102700403065346230343536633236366665306433396164313535346131663462663731323433376163666462376633393965353466316631623032306164343438623510200006024231cede15101e000844
291
292This can be used to update the externally stored AP configuration and
293then update hostapd configuration (followed by restarting of hostapd).
294
295
296WPS with NFC
297------------
298
299WPS can be used with NFC-based configuration method. An NFC tag
300containing a password token from the Enrollee can be used to
301authenticate the connection instead of the PIN. In addition, an NFC tag
302with a configuration token can be used to transfer AP settings without
303going through the WPS protocol.
304
305When the AP acts as an Enrollee, a local NFC tag with a password token
306can be used by touching the NFC interface of an external Registrar. The
307wps_nfc_token command is used to manage use of the NFC password token
308from the AP. "wps_nfc_token enable" enables the use of the AP's NFC
309password token (in place of AP PIN) and "wps_nfc_token disable" disables
310the NFC password token.
311
312The NFC password token that is either pre-configured in the
313configuration file (wps_nfc_dev_pw_id, wps_nfc_dh_pubkey,
314wps_nfc_dh_privkey, wps_nfc_dev_pw) or generated dynamically with
315"wps_nfc_token <WPS|NDEF>" command. The nfc_pw_token tool from
316wpa_supplicant can be used to generate NFC password tokens during
317manufacturing (each AP needs to have its own random keys).
318
319The "wps_nfc_config_token <WPS/NDEF>" command can be used to build an
320NFC configuration token. The output value from this command is a hexdump
321of the current AP configuration (WPS parameter requests this to include
322only the WPS attributes; NDEF parameter requests additional NDEF
323encapsulation to be included). This data needs to be written to an NFC
324tag with an external program. Once written, the NFC configuration token
325can be used to touch an NFC interface on a station to provision the
326credentials needed to access the network.
327
328When the NFC device on the AP reads an NFC tag with a MIME media type
329"application/vnd.wfa.wsc", the NDEF message payload (with or without
330NDEF encapsulation) can be delivered to hostapd using the
331following hostapd_cli command:
332
333wps_nfc_tag_read <hexdump of payload>
334
335If the NFC tag contains a password token, the token is added to the
336internal Registrar. This allows station Enrollee from which the password
337token was received to run through WPS protocol to provision the
338credential.
339
340"nfc_get_handover_sel <NDEF> <WPS>" command can be used to build the
341contents of a Handover Select Message for connection handover when this
342does not depend on the contents of the Handover Request Message. The
343first argument selects the format of the output data and the second
344argument selects which type of connection handover is requested (WPS =
345Wi-Fi handover as specified in WSC 2.0).
346
347"nfc_report_handover <INIT/RESP> WPS <carrier from handover request>
348<carrier from handover select>" is used to report completed NFC
349connection handover. The first parameter indicates whether the local
350device initiated or responded to the connection handover and the carrier
351records are the selected carrier from the handover request and select
352messages as a hexdump.
353