1wpa_supplicant and Hotspot 2.0 2============================== 3 4This document describe how the IEEE 802.11u Interworking and Wi-Fi 5Hotspot 2.0 (Release 1) implementation in wpa_supplicant can be 6configured and how an external component on the client e.g., management 7GUI or Wi-Fi framework) is used to manage this functionality. 8 9 10Introduction to Wi-Fi Hotspot 2.0 11--------------------------------- 12 13Hotspot 2.0 is the name of the Wi-Fi Alliance specification that is used 14in the Wi-Fi CERTIFIED Passpoint<TM> program. More information about 15this is available in this white paper: 16 17http://www.wi-fi.org/knowledge-center/white-papers/wi-fi-certified-passpoint%E2%84%A2-new-program-wi-fi-alliance%C2%AE-enable-seamless 18 19The Hotspot 2.0 specification is also available from WFA: 20https://www.wi-fi.org/knowledge-center/published-specifications 21 22The core Interworking functionality (network selection, GAS/ANQP) were 23standardized in IEEE Std 802.11u-2011 which is now part of the IEEE Std 24802.11-2012. 25 26 27wpa_supplicant network selection 28-------------------------------- 29 30Interworking support added option for configuring credentials that can 31work with multiple networks as an alternative to configuration of 32network blocks (e.g., per-SSID parameters). When requested to perform 33network selection, wpa_supplicant picks the highest priority enabled 34network block or credential. If a credential is picked (based on ANQP 35information from APs), a temporary network block is created 36automatically for the matching network. This temporary network block is 37used similarly to the network blocks that can be configured by the user, 38but it is not stored into the configuration file and is meant to be used 39only for temporary period of time since a new one can be created 40whenever needed based on ANQP information and the credential. 41 42By default, wpa_supplicant is not using automatic network selection 43unless requested explicitly with the interworking_select command. This 44can be changed with the auto_interworking=1 parameter to perform network 45selection automatically whenever trying to find a network for connection 46and none of the enabled network blocks match with the scan results. This 47case works similarly to "interworking_select auto", i.e., wpa_supplicant 48will internally determine which network or credential is going to be 49used based on configured priorities, scan results, and ANQP information. 50 51 52wpa_supplicant configuration 53---------------------------- 54 55Interworking and Hotspot 2.0 functionality are optional components that 56need to be enabled in the wpa_supplicant build configuration 57(.config). This is done by adding following parameters into that file: 58 59CONFIG_INTERWORKING=y 60CONFIG_HS20=y 61 62It should be noted that this functionality requires a driver that 63supports GAS/ANQP operations. This uses the same design as P2P, i.e., 64Action frame processing and building in user space within 65wpa_supplicant. The Linux nl80211 driver interface provides the needed 66functionality for this. 67 68 69There are number of run-time configuration parameters (e.g., in 70wpa_supplicant.conf when using the configuration file) that can be used 71to control Hotspot 2.0 operations. 72 73# Enable Interworking 74interworking=1 75 76# Enable Hotspot 2.0 77hs20=1 78 79# Parameters for controlling scanning 80 81# Homogenous ESS identifier 82# If this is set, scans will be used to request response only from BSSes 83# belonging to the specified Homogeneous ESS. This is used only if interworking 84# is enabled. 85#hessid=00:11:22:33:44:55 86 87# Access Network Type 88# When Interworking is enabled, scans can be limited to APs that advertise the 89# specified Access Network Type (0..15; with 15 indicating wildcard match). 90# This value controls the Access Network Type value in Probe Request frames. 91#access_network_type=15 92 93# Automatic network selection behavior 94# 0 = do not automatically go through Interworking network selection 95# (i.e., require explicit interworking_select command for this; default) 96# 1 = perform Interworking network selection if one or more 97# credentials have been configured and scan did not find a 98# matching network block 99#auto_interworking=0 100 101 102Credentials can be pre-configured for automatic network selection: 103 104# credential block 105# 106# Each credential used for automatic network selection is configured as a set 107# of parameters that are compared to the information advertised by the APs when 108# interworking_select and interworking_connect commands are used. 109# 110# credential fields: 111# 112# priority: Priority group 113# By default, all networks and credentials get the same priority group 114# (0). This field can be used to give higher priority for credentials 115# (and similarly in struct wpa_ssid for network blocks) to change the 116# Interworking automatic networking selection behavior. The matching 117# network (based on either an enabled network block or a credential) 118# with the highest priority value will be selected. 119# 120# pcsc: Use PC/SC and SIM/USIM card 121# 122# realm: Home Realm for Interworking 123# 124# username: Username for Interworking network selection 125# 126# password: Password for Interworking network selection 127# 128# ca_cert: CA certificate for Interworking network selection 129# 130# client_cert: File path to client certificate file (PEM/DER) 131# This field is used with Interworking networking selection for a case 132# where client certificate/private key is used for authentication 133# (EAP-TLS). Full path to the file should be used since working 134# directory may change when wpa_supplicant is run in the background. 135# 136# Alternatively, a named configuration blob can be used by setting 137# this to blob://blob_name. 138# 139# private_key: File path to client private key file (PEM/DER/PFX) 140# When PKCS#12/PFX file (.p12/.pfx) is used, client_cert should be 141# commented out. Both the private key and certificate will be read 142# from the PKCS#12 file in this case. Full path to the file should be 143# used since working directory may change when wpa_supplicant is run 144# in the background. 145# 146# Windows certificate store can be used by leaving client_cert out and 147# configuring private_key in one of the following formats: 148# 149# cert://substring_to_match 150# 151# hash://certificate_thumbprint_in_hex 152# 153# For example: private_key="hash://63093aa9c47f56ae88334c7b65a4" 154# 155# Note that when running wpa_supplicant as an application, the user 156# certificate store (My user account) is used, whereas computer store 157# (Computer account) is used when running wpasvc as a service. 158# 159# Alternatively, a named configuration blob can be used by setting 160# this to blob://blob_name. 161# 162# private_key_passwd: Password for private key file 163# 164# imsi: IMSI in <MCC> | <MNC> | '-' | <MSIN> format 165# 166# milenage: Milenage parameters for SIM/USIM simulator in <Ki>:<OPc>:<SQN> 167# format 168# 169# domain: Home service provider FQDN 170# This is used to compare against the Domain Name List to figure out 171# whether the AP is operated by the Home SP. 172# 173# roaming_consortium: Roaming Consortium OI 174# If roaming_consortium_len is non-zero, this field contains the 175# Roaming Consortium OI that can be used to determine which access 176# points support authentication with this credential. This is an 177# alternative to the use of the realm parameter. When using Roaming 178# Consortium to match the network, the EAP parameters need to be 179# pre-configured with the credential since the NAI Realm information 180# may not be available or fetched. 181# 182# eap: Pre-configured EAP method 183# This optional field can be used to specify which EAP method will be 184# used with this credential. If not set, the EAP method is selected 185# automatically based on ANQP information (e.g., NAI Realm). 186# 187# phase1: Pre-configure Phase 1 (outer authentication) parameters 188# This optional field is used with like the 'eap' parameter. 189# 190# phase2: Pre-configure Phase 2 (inner authentication) parameters 191# This optional field is used with like the 'eap' parameter. 192# 193# for example: 194# 195#cred={ 196# realm="example.com" 197# username="user@example.com" 198# password="password" 199# ca_cert="/etc/wpa_supplicant/ca.pem" 200# domain="example.com" 201#} 202# 203#cred={ 204# imsi="310026-000000000" 205# milenage="90dca4eda45b53cf0f12d7c9c3bc6a89:cb9cccc4b9258e6dca4760379fb82" 206#} 207# 208#cred={ 209# realm="example.com" 210# username="user" 211# password="password" 212# ca_cert="/etc/wpa_supplicant/ca.pem" 213# domain="example.com" 214# roaming_consortium=223344 215# eap=TTLS 216# phase2="auth=MSCHAPV2" 217#} 218 219 220Control interface 221----------------- 222 223wpa_supplicant provides a control interface that can be used from 224external programs to manage various operations. The included command 225line tool, wpa_cli, can be used for manual testing with this interface. 226 227Following wpa_cli interactive mode commands show some examples of manual 228operations related to Hotspot 2.0: 229 230Remove configured networks and credentials: 231 232> remove_network all 233OK 234> remove_cred all 235OK 236 237 238Add a username/password credential: 239 240> add_cred 2410 242> set_cred 0 realm "mail.example.com" 243OK 244> set_cred 0 username "username" 245OK 246> set_cred 0 password "password" 247OK 248> set_cred 0 priority 1 249OK 250 251Add a SIM credential using a simulated SIM/USIM card for testing: 252 253> add_cred 2541 255> set_cred 1 imsi "23456-0000000000" 256OK 257> set_cred 1 milenage "90dca4eda45b53cf0f12d7c9c3bc6a89:cb9cccc4b9258e6dca4760379fb82581:000000000123" 258OK 259> set_cred 1 priority 1 260OK 261 262Note: the return value of add_cred is used as the first argument to 263the following set_cred commands. 264 265 266Add a WPA2-Enterprise network: 267 268> add_network 2690 270> set_network 0 key_mgmt WPA-EAP 271OK 272> set_network 0 ssid "enterprise" 273OK 274> set_network 0 eap TTLS 275OK 276> set_network 0 anonymous_identity "anonymous" 277OK 278> set_network 0 identity "user" 279OK 280> set_network 0 password "password" 281OK 282> set_network 0 priority 0 283OK 284> enable_network 0 no-connect 285OK 286 287 288Add an open network: 289 290> add_network 2913 292> set_network 3 key_mgmt NONE 293OK 294> set_network 3 ssid "coffee-shop" 295OK 296> select_network 3 297OK 298 299Note: the return value of add_network is used as the first argument to 300the following set_network commands. 301 302The preferred credentials/networks can be indicated with the priority 303parameter (1 is higher priority than 0). 304 305 306Interworking network selection can be started with interworking_select 307command. This instructs wpa_supplicant to run a network scan and iterate 308through the discovered APs to request ANQP information from the APs that 309advertise support for Interworking/Hotspot 2.0: 310 311> interworking_select 312OK 313<3>Starting ANQP fetch for 02:00:00:00:01:00 314<3>RX-ANQP 02:00:00:00:01:00 ANQP Capability list 315<3>RX-ANQP 02:00:00:00:01:00 Roaming Consortium list 316<3>RX-HS20-ANQP 02:00:00:00:01:00 HS Capability List 317<3>ANQP fetch completed 318<3>INTERWORKING-AP 02:00:00:00:01:00 type=unknown 319 320 321INTERWORKING-AP event messages indicate the APs that support network 322selection and for which there is a matching 323credential. interworking_connect command can be used to select a network 324to connect with: 325 326 327> interworking_connect 02:00:00:00:01:00 328OK 329<3>CTRL-EVENT-SCAN-RESULTS 330<3>SME: Trying to authenticate with 02:00:00:00:01:00 (SSID='Example Network' freq=2412 MHz) 331<3>Trying to associate with 02:00:00:00:01:00 (SSID='Example Network' freq=2412 MHz) 332<3>Associated with 02:00:00:00:01:00 333<3>CTRL-EVENT-EAP-STARTED EAP authentication started 334<3>CTRL-EVENT-EAP-PROPOSED-METHOD vendor=0 method=21 335<3>CTRL-EVENT-EAP-METHOD EAP vendor 0 method 21 (TTLS) selected 336<3>CTRL-EVENT-EAP-SUCCESS EAP authentication completed successfully 337<3>WPA: Key negotiation completed with 02:00:00:00:01:00 [PTK=CCMP GTK=CCMP] 338<3>CTRL-EVENT-CONNECTED - Connection to 02:00:00:00:01:00 completed (auth) [id=0 id_str=] 339 340 341wpa_supplicant creates a temporary network block for the selected 342network based on the configured credential and ANQP information from the 343AP: 344 345> list_networks 346network id / ssid / bssid / flags 3470 Example Network any [CURRENT] 348> get_network 0 key_mgmt 349WPA-EAP 350> get_network 0 eap 351TTLS 352 353 354Alternatively to using an external program to select the network, 355"interworking_select auto" command can be used to request wpa_supplicant 356to select which network to use based on configured priorities: 357 358 359> remove_network all 360OK 361<3>CTRL-EVENT-DISCONNECTED bssid=02:00:00:00:01:00 reason=1 locally_generated=1 362> interworking_select auto 363OK 364<3>Starting ANQP fetch for 02:00:00:00:01:00 365<3>RX-ANQP 02:00:00:00:01:00 ANQP Capability list 366<3>RX-ANQP 02:00:00:00:01:00 Roaming Consortium list 367<3>RX-HS20-ANQP 02:00:00:00:01:00 HS Capability List 368<3>ANQP fetch completed 369<3>INTERWORKING-AP 02:00:00:00:01:00 type=unknown 370<3>CTRL-EVENT-SCAN-RESULTS 371<3>SME: Trying to authenticate with 02:00:00:00:01:00 (SSID='Example Network' freq=2412 MHz) 372<3>Trying to associate with 02:00:00:00:01:00 (SSID='Example Network' freq=2412 MHz) 373<3>Associated with 02:00:00:00:01:00 374<3>CTRL-EVENT-EAP-STARTED EAP authentication started 375<3>CTRL-EVENT-EAP-PROPOSED-METHOD vendor=0 method=21 376<3>CTRL-EVENT-EAP-METHOD EAP vendor 0 method 21 (TTLS) selected 377<3>CTRL-EVENT-EAP-SUCCESS EAP authentication completed successfully 378<3>WPA: Key negotiation completed with 02:00:00:00:01:00 [PTK=CCMP GTK=CCMP] 379<3>CTRL-EVENT-CONNECTED - Connection to 02:00:00:00:01:00 completed (reauth) [id=0 id_str=] 380 381 382The connection status can be shown with the status command: 383 384> status 385bssid=02:00:00:00:01:00 386ssid=Example Network 387id=0 388mode=station 389pairwise_cipher=CCMP <--- link layer security indication 390group_cipher=CCMP 391key_mgmt=WPA2/IEEE 802.1X/EAP 392wpa_state=COMPLETED 393p2p_device_address=02:00:00:00:00:00 394address=02:00:00:00:00:00 395hs20=1 <--- HS 2.0 indication 396Supplicant PAE state=AUTHENTICATED 397suppPortStatus=Authorized 398EAP state=SUCCESS 399selectedMethod=21 (EAP-TTLS) 400EAP TLS cipher=AES-128-SHA 401EAP-TTLSv0 Phase2 method=PAP 402 403 404> status 405bssid=02:00:00:00:02:00 406ssid=coffee-shop 407id=3 408mode=station 409pairwise_cipher=NONE 410group_cipher=NONE 411key_mgmt=NONE 412wpa_state=COMPLETED 413p2p_device_address=02:00:00:00:00:00 414address=02:00:00:00:00:00 415 416 417Note: The Hotspot 2.0 indication is shown as "hs20=1" in the status 418command output. Link layer security is indicated with the 419pairwise_cipher (CCMP = secure, NONE = no encryption used). 420 421 422Also the scan results include the Hotspot 2.0 indication: 423 424> scan_results 425bssid / frequency / signal level / flags / ssid 42602:00:00:00:01:00 2412 -30 [WPA2-EAP-CCMP][ESS][HS20] Example Network 427 428 429ANQP information for the BSS can be fetched using the BSS command: 430 431> bss 02:00:00:00:01:00 432id=1 433bssid=02:00:00:00:01:00 434freq=2412 435beacon_int=100 436capabilities=0x0411 437qual=0 438noise=-92 439level=-30 440tsf=1345573286517276 441age=105 442ie=000f4578616d706c65204e6574776f726b010882848b960c1218240301012a010432043048606c30140100000fac040100000fac040100000fac0100007f04000000806b091e07010203040506076c027f006f1001531122331020304050010203040506dd05506f9a1000 443flags=[WPA2-EAP-CCMP][ESS][HS20] 444ssid=Example Network 445anqp_roaming_consortium=031122330510203040500601020304050603fedcba 446 447 448ANQP queries can also be requested with the anqp_get and hs20_anqp_get 449commands: 450 451> anqp_get 02:00:00:00:01:00 261 452OK 453<3>RX-ANQP 02:00:00:00:01:00 Roaming Consortium list 454> hs20_anqp_get 02:00:00:00:01:00 2 455OK 456<3>RX-HS20-ANQP 02:00:00:00:01:00 HS Capability List 457 458In addition, fetch_anqp command can be used to request similar set of 459ANQP queries to be done as is run as part of interworking_select: 460 461> scan 462OK 463<3>CTRL-EVENT-SCAN-RESULTS 464> fetch_anqp 465OK 466<3>Starting ANQP fetch for 02:00:00:00:01:00 467<3>RX-ANQP 02:00:00:00:01:00 ANQP Capability list 468<3>RX-ANQP 02:00:00:00:01:00 Roaming Consortium list 469<3>RX-HS20-ANQP 02:00:00:00:01:00 HS Capability List 470<3>ANQP fetch completed 471