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# temporary: Whether this credential is temporary and not to be saved 113# 114# priority: Priority group 115# By default, all networks and credentials get the same priority group 116# (0). This field can be used to give higher priority for credentials 117# (and similarly in struct wpa_ssid for network blocks) to change the 118# Interworking automatic networking selection behavior. The matching 119# network (based on either an enabled network block or a credential) 120# with the highest priority value will be selected. 121# 122# pcsc: Use PC/SC and SIM/USIM card 123# 124# realm: Home Realm for Interworking 125# 126# username: Username for Interworking network selection 127# 128# password: Password for Interworking network selection 129# 130# ca_cert: CA certificate for Interworking network selection 131# 132# client_cert: File path to client certificate file (PEM/DER) 133# This field is used with Interworking networking selection for a case 134# where client certificate/private key is used for authentication 135# (EAP-TLS). Full path to the file should be used since working 136# directory may change when wpa_supplicant is run in the background. 137# 138# Alternatively, a named configuration blob can be used by setting 139# this to blob://blob_name. 140# 141# private_key: File path to client private key file (PEM/DER/PFX) 142# When PKCS#12/PFX file (.p12/.pfx) is used, client_cert should be 143# commented out. Both the private key and certificate will be read 144# from the PKCS#12 file in this case. Full path to the file should be 145# used since working directory may change when wpa_supplicant is run 146# in the background. 147# 148# Windows certificate store can be used by leaving client_cert out and 149# configuring private_key in one of the following formats: 150# 151# cert://substring_to_match 152# 153# hash://certificate_thumbprint_in_hex 154# 155# For example: private_key="hash://63093aa9c47f56ae88334c7b65a4" 156# 157# Note that when running wpa_supplicant as an application, the user 158# certificate store (My user account) is used, whereas computer store 159# (Computer account) is used when running wpasvc as a service. 160# 161# Alternatively, a named configuration blob can be used by setting 162# this to blob://blob_name. 163# 164# private_key_passwd: Password for private key file 165# 166# imsi: IMSI in <MCC> | <MNC> | '-' | <MSIN> format 167# 168# milenage: Milenage parameters for SIM/USIM simulator in <Ki>:<OPc>:<SQN> 169# format 170# 171# domain_suffix_match: Constraint for server domain name 172# If set, this FQDN is used as a suffix match requirement for the AAA 173# server certificate in SubjectAltName dNSName element(s). If a 174# matching dNSName is found, this constraint is met. If no dNSName 175# values are present, this constraint is matched against SubjectName CN 176# using same suffix match comparison. Suffix match here means that the 177# host/domain name is compared one label at a time starting from the 178# top-level domain and all the labels in @domain_suffix_match shall be 179# included in the certificate. The certificate may include additional 180# sub-level labels in addition to the required labels. 181# 182# For example, domain_suffix_match=example.com would match 183# test.example.com but would not match test-example.com. 184# 185# domain: Home service provider FQDN(s) 186# This is used to compare against the Domain Name List to figure out 187# whether the AP is operated by the Home SP. Multiple domain entries can 188# be used to configure alternative FQDNs that will be considered home 189# networks. 190# 191# roaming_consortium: Roaming Consortium OI 192# If roaming_consortium_len is non-zero, this field contains the 193# Roaming Consortium OI that can be used to determine which access 194# points support authentication with this credential. This is an 195# alternative to the use of the realm parameter. When using Roaming 196# Consortium to match the network, the EAP parameters need to be 197# pre-configured with the credential since the NAI Realm information 198# may not be available or fetched. 199# 200# required_roaming_consortium: Required Roaming Consortium OI 201# If required_roaming_consortium_len is non-zero, this field contains the 202# Roaming Consortium OI that is required to be advertised by the AP for 203# the credential to be considered matching. 204# 205# roaming_consortiums: Roaming Consortium OI(s) memberships 206# This string field contains one or more comma delimited OIs (hexdump) 207# identifying the roaming consortiums of which the provider is a member. 208# The list is sorted from the most preferred one to the least preferred 209# one. A match between the Roaming Consortium OIs advertised by an AP and 210# the OIs in this list indicates that successful authentication is 211# possible. 212# (Hotspot 2.0 PerProviderSubscription/<X+>/HomeSP/RoamingConsortiumOI) 213# 214# eap: Pre-configured EAP method 215# This optional field can be used to specify which EAP method will be 216# used with this credential. If not set, the EAP method is selected 217# automatically based on ANQP information (e.g., NAI Realm). 218# 219# phase1: Pre-configure Phase 1 (outer authentication) parameters 220# This optional field is used with like the 'eap' parameter. 221# 222# phase2: Pre-configure Phase 2 (inner authentication) parameters 223# This optional field is used with like the 'eap' parameter. 224# 225# excluded_ssid: Excluded SSID 226# This optional field can be used to excluded specific SSID(s) from 227# matching with the network. Multiple entries can be used to specify more 228# than one SSID. 229# 230# roaming_partner: Roaming partner information 231# This optional field can be used to configure preferences between roaming 232# partners. The field is a string in following format: 233# <FQDN>,<0/1 exact match>,<priority>,<* or country code> 234# (non-exact match means any subdomain matches the entry; priority is in 235# 0..255 range with 0 being the highest priority) 236# 237# update_identifier: PPS MO ID 238# (Hotspot 2.0 PerProviderSubscription/UpdateIdentifier) 239# 240# provisioning_sp: FQDN of the SP that provisioned the credential 241# This optional field can be used to keep track of the SP that provisioned 242# the credential to find the PPS MO (./Wi-Fi/<provisioning_sp>). 243# 244# sp_priority: Credential priority within a provisioning SP 245# This is the priority of the credential among all credentials 246# provisioned by the same SP (i.e., for entries that have identical 247# provisioning_sp value). The range of this priority is 0-255 with 0 248# being the highest and 255 the lower priority. 249# 250# Minimum backhaul threshold (PPS/<X+>/Policy/MinBackhauldThreshold/*) 251# These fields can be used to specify minimum download/upload backhaul 252# bandwidth that is preferred for the credential. This constraint is 253# ignored if the AP does not advertise WAN Metrics information or if the 254# limit would prevent any connection. Values are in kilobits per second. 255# min_dl_bandwidth_home 256# min_ul_bandwidth_home 257# min_dl_bandwidth_roaming 258# min_ul_bandwidth_roaming 259# 260# max_bss_load: Maximum BSS Load Channel Utilization (1..255) 261# (PPS/<X+>/Policy/MaximumBSSLoadValue) 262# This value is used as the maximum channel utilization for network 263# selection purposes for home networks. If the AP does not advertise 264# BSS Load or if the limit would prevent any connection, this constraint 265# will be ignored. 266# 267# req_conn_capab: Required connection capability 268# (PPS/<X+>/Policy/RequiredProtoPortTuple) 269# This value is used to configure set of required protocol/port pairs that 270# a roaming network shall support (include explicitly in Connection 271# Capability ANQP element). This constraint is ignored if the AP does not 272# advertise Connection Capability or if this constraint would prevent any 273# network connection. This policy is not used in home networks. 274# Format: <protocol>[:<comma-separated list of ports] 275# Multiple entries can be used to list multiple requirements. 276# For example, number of common TCP protocols: 277# req_conn_capab=6:22,80,443 278# For example, IPSec/IKE: 279# req_conn_capab=17:500 280# req_conn_capab=50 281# 282# ocsp: Whether to use/require OCSP to check server certificate 283# 0 = do not use OCSP stapling (TLS certificate status extension) 284# 1 = try to use OCSP stapling, but not require response 285# 2 = require valid OCSP stapling response 286# 287# sim_num: Identifier for which SIM to use in multi-SIM devices 288# 289# for example: 290# 291#cred={ 292# realm="example.com" 293# username="user@example.com" 294# password="password" 295# ca_cert="/etc/wpa_supplicant/ca.pem" 296# domain="example.com" 297# domain_suffix_match="example.com" 298#} 299# 300#cred={ 301# imsi="310026-000000000" 302# milenage="90dca4eda45b53cf0f12d7c9c3bc6a89:cb9cccc4b9258e6dca4760379fb82" 303#} 304# 305#cred={ 306# realm="example.com" 307# username="user" 308# password="password" 309# ca_cert="/etc/wpa_supplicant/ca.pem" 310# domain="example.com" 311# roaming_consortium=223344 312# roaming_consortiums="112233,4455667788,aabbcc" 313# eap=TTLS 314# phase2="auth=MSCHAPV2" 315#} 316 317 318Control interface 319----------------- 320 321wpa_supplicant provides a control interface that can be used from 322external programs to manage various operations. The included command 323line tool, wpa_cli, can be used for manual testing with this interface. 324 325Following wpa_cli interactive mode commands show some examples of manual 326operations related to Hotspot 2.0: 327 328Remove configured networks and credentials: 329 330> remove_network all 331OK 332> remove_cred all 333OK 334 335 336Add a username/password credential: 337 338> add_cred 3390 340> set_cred 0 realm "mail.example.com" 341OK 342> set_cred 0 username "username" 343OK 344> set_cred 0 password "password" 345OK 346> set_cred 0 priority 1 347OK 348> set_cred 0 temporary 1 349OK 350 351Add a SIM credential using a simulated SIM/USIM card for testing: 352 353> add_cred 3541 355> set_cred 1 imsi "23456-0000000000" 356OK 357> set_cred 1 milenage "90dca4eda45b53cf0f12d7c9c3bc6a89:cb9cccc4b9258e6dca4760379fb82581:000000000123" 358OK 359> set_cred 1 priority 1 360OK 361 362Note: the return value of add_cred is used as the first argument to 363the following set_cred commands. 364 365Add a SIM credential using a external SIM/USIM processing: 366 367> set external_sim 1 368OK 369> add_cred 3701 371> set_cred 1 imsi "23456-0000000000" 372OK 373> set_cred 1 eap SIM 374OK 375 376 377Add a WPA2-Enterprise network: 378 379> add_network 3800 381> set_network 0 key_mgmt WPA-EAP 382OK 383> set_network 0 ssid "enterprise" 384OK 385> set_network 0 eap TTLS 386OK 387> set_network 0 anonymous_identity "anonymous" 388OK 389> set_network 0 identity "user" 390OK 391> set_network 0 password "password" 392OK 393> set_network 0 priority 0 394OK 395> enable_network 0 no-connect 396OK 397 398 399Add an open network: 400 401> add_network 4023 403> set_network 3 key_mgmt NONE 404OK 405> set_network 3 ssid "coffee-shop" 406OK 407> select_network 3 408OK 409 410Note: the return value of add_network is used as the first argument to 411the following set_network commands. 412 413The preferred credentials/networks can be indicated with the priority 414parameter (1 is higher priority than 0). 415 416 417Interworking network selection can be started with interworking_select 418command. This instructs wpa_supplicant to run a network scan and iterate 419through the discovered APs to request ANQP information from the APs that 420advertise support for Interworking/Hotspot 2.0: 421 422> interworking_select 423OK 424<3>Starting ANQP fetch for 02:00:00:00:01:00 425<3>RX-ANQP 02:00:00:00:01:00 ANQP Capability list 426<3>RX-ANQP 02:00:00:00:01:00 Roaming Consortium list 427<3>RX-HS20-ANQP 02:00:00:00:01:00 HS Capability List 428<3>ANQP fetch completed 429<3>INTERWORKING-AP 02:00:00:00:01:00 type=unknown 430 431 432INTERWORKING-AP event messages indicate the APs that support network 433selection and for which there is a matching 434credential. interworking_connect command can be used to select a network 435to connect with: 436 437 438> interworking_connect 02:00:00:00:01:00 439OK 440<3>CTRL-EVENT-SCAN-RESULTS 441<3>SME: Trying to authenticate with 02:00:00:00:01:00 (SSID='Example Network' freq=2412 MHz) 442<3>Trying to associate with 02:00:00:00:01:00 (SSID='Example Network' freq=2412 MHz) 443<3>Associated with 02:00:00:00:01:00 444<3>CTRL-EVENT-EAP-STARTED EAP authentication started 445<3>CTRL-EVENT-EAP-PROPOSED-METHOD vendor=0 method=21 446<3>CTRL-EVENT-EAP-METHOD EAP vendor 0 method 21 (TTLS) selected 447<3>CTRL-EVENT-EAP-SUCCESS EAP authentication completed successfully 448<3>WPA: Key negotiation completed with 02:00:00:00:01:00 [PTK=CCMP GTK=CCMP] 449<3>CTRL-EVENT-CONNECTED - Connection to 02:00:00:00:01:00 completed (auth) [id=0 id_str=] 450 451 452wpa_supplicant creates a temporary network block for the selected 453network based on the configured credential and ANQP information from the 454AP: 455 456> list_networks 457network id / ssid / bssid / flags 4580 Example Network any [CURRENT] 459> get_network 0 key_mgmt 460WPA-EAP 461> get_network 0 eap 462TTLS 463 464 465Alternatively to using an external program to select the network, 466"interworking_select auto" command can be used to request wpa_supplicant 467to select which network to use based on configured priorities: 468 469 470> remove_network all 471OK 472<3>CTRL-EVENT-DISCONNECTED bssid=02:00:00:00:01:00 reason=1 locally_generated=1 473> interworking_select auto 474OK 475<3>Starting ANQP fetch for 02:00:00:00:01:00 476<3>RX-ANQP 02:00:00:00:01:00 ANQP Capability list 477<3>RX-ANQP 02:00:00:00:01:00 Roaming Consortium list 478<3>RX-HS20-ANQP 02:00:00:00:01:00 HS Capability List 479<3>ANQP fetch completed 480<3>INTERWORKING-AP 02:00:00:00:01:00 type=unknown 481<3>CTRL-EVENT-SCAN-RESULTS 482<3>SME: Trying to authenticate with 02:00:00:00:01:00 (SSID='Example Network' freq=2412 MHz) 483<3>Trying to associate with 02:00:00:00:01:00 (SSID='Example Network' freq=2412 MHz) 484<3>Associated with 02:00:00:00:01:00 485<3>CTRL-EVENT-EAP-STARTED EAP authentication started 486<3>CTRL-EVENT-EAP-PROPOSED-METHOD vendor=0 method=21 487<3>CTRL-EVENT-EAP-METHOD EAP vendor 0 method 21 (TTLS) selected 488<3>CTRL-EVENT-EAP-SUCCESS EAP authentication completed successfully 489<3>WPA: Key negotiation completed with 02:00:00:00:01:00 [PTK=CCMP GTK=CCMP] 490<3>CTRL-EVENT-CONNECTED - Connection to 02:00:00:00:01:00 completed (reauth) [id=0 id_str=] 491 492 493The connection status can be shown with the status command: 494 495> status 496bssid=02:00:00:00:01:00 497ssid=Example Network 498id=0 499mode=station 500pairwise_cipher=CCMP <--- link layer security indication 501group_cipher=CCMP 502key_mgmt=WPA2/IEEE 802.1X/EAP 503wpa_state=COMPLETED 504p2p_device_address=02:00:00:00:00:00 505address=02:00:00:00:00:00 506hs20=1 <--- HS 2.0 indication 507Supplicant PAE state=AUTHENTICATED 508suppPortStatus=Authorized 509EAP state=SUCCESS 510selectedMethod=21 (EAP-TTLS) 511EAP TLS cipher=AES-128-SHA 512EAP-TTLSv0 Phase2 method=PAP 513 514 515> status 516bssid=02:00:00:00:02:00 517ssid=coffee-shop 518id=3 519mode=station 520pairwise_cipher=NONE 521group_cipher=NONE 522key_mgmt=NONE 523wpa_state=COMPLETED 524p2p_device_address=02:00:00:00:00:00 525address=02:00:00:00:00:00 526 527 528Note: The Hotspot 2.0 indication is shown as "hs20=1" in the status 529command output. Link layer security is indicated with the 530pairwise_cipher (CCMP = secure, NONE = no encryption used). 531 532 533Also the scan results include the Hotspot 2.0 indication: 534 535> scan_results 536bssid / frequency / signal level / flags / ssid 53702:00:00:00:01:00 2412 -30 [WPA2-EAP-CCMP][ESS][HS20] Example Network 538 539 540ANQP information for the BSS can be fetched using the BSS command: 541 542> bss 02:00:00:00:01:00 543id=1 544bssid=02:00:00:00:01:00 545freq=2412 546beacon_int=100 547capabilities=0x0411 548qual=0 549noise=-92 550level=-30 551tsf=1345573286517276 552age=105 553ie=000f4578616d706c65204e6574776f726b010882848b960c1218240301012a010432043048606c30140100000fac040100000fac040100000fac0100007f04000000806b091e07010203040506076c027f006f1001531122331020304050010203040506dd05506f9a1000 554flags=[WPA2-EAP-CCMP][ESS][HS20] 555ssid=Example Network 556anqp_roaming_consortium=031122330510203040500601020304050603fedcba 557 558 559ANQP queries can also be requested with the anqp_get and hs20_anqp_get 560commands: 561 562> anqp_get 02:00:00:00:01:00 261 563OK 564<3>RX-ANQP 02:00:00:00:01:00 Roaming Consortium list 565> hs20_anqp_get 02:00:00:00:01:00 2 566OK 567<3>RX-HS20-ANQP 02:00:00:00:01:00 HS Capability List 568 569In addition, fetch_anqp command can be used to request similar set of 570ANQP queries to be done as is run as part of interworking_select: 571 572> scan 573OK 574<3>CTRL-EVENT-SCAN-RESULTS 575> fetch_anqp 576OK 577<3>Starting ANQP fetch for 02:00:00:00:01:00 578<3>RX-ANQP 02:00:00:00:01:00 ANQP Capability list 579<3>RX-ANQP 02:00:00:00:01:00 Roaming Consortium list 580<3>RX-HS20-ANQP 02:00:00:00:01:00 HS Capability List 581<3>ANQP fetch completed 582 583 584Hotspot 2.0 Rel 2 online signup and OSEN 585---------------------------------------- 586 587Following parameters can be used to create a network profile for 588link-layer protected Hotspot 2.0 online signup connection with 589OSEN. Note that ssid and identify (NAI) values need to be set based on 590the information for the selected provider in the OSU Providers list 591ANQP-element. 592 593network={ 594 ssid="HS 2.0 OSU" 595 proto=OSEN 596 key_mgmt=OSEN 597 pairwise=CCMP 598 group=GTK_NOT_USED 599 eap=WFA-UNAUTH-TLS 600 identity="anonymous@example.com" 601 ca_cert="osu-ca.pem" 602 ocsp=2 603} 604 605 606Hotspot 2.0 connection with external network selection 607------------------------------------------------------ 608 609When a component controlling wpa_supplicant takes care of Interworking 610network selection, following configuration and network profile 611parameters can be used to configure a temporary network profile for a 612Hotspot 2.0 connection (e.g., with SET, ADD_NETWORK, SET_NETWORK, and 613SELECT_NETWORK control interface commands): 614 615interworking=1 616hs20=1 617auto_interworking=0 618 619network={ 620 ssid="test-hs20" 621 proto=RSN 622 key_mgmt=WPA-EAP 623 pairwise=CCMP 624 anonymous_identity="anonymous@example.com" 625 identity="hs20-test@example.com" 626 password="password" 627 ca_cert="ca.pem" 628 eap=TTLS 629 phase2="auth=MSCHAPV2" 630 update_identifier=54321 631 roaming_consortium_selection=112233 632 #ocsp=2 633} 634 635 636These parameters are set based on the PPS MO credential and/or NAI Realm 637list ANQP-element: 638 639anonymous_identity: Credential/UsernamePassword/Username with username part 640 replaced with "anonymous" 641identity: Credential/UsernamePassword/Username 642password: Credential/UsernamePassword/Password 643update_identifier: PPS/UpdateIdentifier 644ca_cert: from the downloaded trust root based on PPS information 645eap: Credential/UsernamePassword/EAPMethod or NAI Realm list 646phase2: Credential/UsernamePassword/EAPMethod or NAI Realm list 647roaming_consortium_selection: Matching OI from HomeSP/RoamingConsortiumOI 648ocsp: Credential/CheckAAAServerCertStatus 649