wps_attr_build.c revision 6cb1f6521a84955752c2b99100cf1df87637f86c
1/* 2 * Wi-Fi Protected Setup - attribute building 3 * Copyright (c) 2008, Jouni Malinen <j@w1.fi> 4 * 5 * This software may be distributed under the terms of the BSD license. 6 * See README for more details. 7 */ 8 9#include "includes.h" 10 11#include "common.h" 12#include "crypto/aes_wrap.h" 13#include "crypto/crypto.h" 14#include "crypto/dh_group5.h" 15#include "crypto/sha256.h" 16#include "crypto/random.h" 17#include "common/ieee802_11_defs.h" 18#include "wps_i.h" 19 20 21int wps_build_public_key(struct wps_data *wps, struct wpabuf *msg) 22{ 23 struct wpabuf *pubkey; 24 25 wpa_printf(MSG_DEBUG, "WPS: * Public Key"); 26 wpabuf_free(wps->dh_privkey); 27 wps->dh_privkey = NULL; 28 if (wps->dev_pw_id != DEV_PW_DEFAULT && wps->wps->dh_privkey && 29 wps->wps->dh_ctx) { 30 wpa_printf(MSG_DEBUG, "WPS: Using pre-configured DH keys"); 31 if (wps->wps->dh_pubkey == NULL) { 32 wpa_printf(MSG_DEBUG, 33 "WPS: wps->wps->dh_pubkey == NULL"); 34 return -1; 35 } 36 wps->dh_privkey = wpabuf_dup(wps->wps->dh_privkey); 37 wps->dh_ctx = wps->wps->dh_ctx; 38 wps->wps->dh_ctx = NULL; 39 pubkey = wpabuf_dup(wps->wps->dh_pubkey); 40#ifdef CONFIG_WPS_NFC 41 } else if ((wps->dev_pw_id >= 0x10 || 42 wps->dev_pw_id == DEV_PW_NFC_CONNECTION_HANDOVER) && 43 (wps->wps->ap || 44 (wps->wps->ap_nfc_dh_pubkey && 45 wps->wps->ap_nfc_dev_pw_id == 46 DEV_PW_NFC_CONNECTION_HANDOVER && 47 wps->dev_pw_id == DEV_PW_NFC_CONNECTION_HANDOVER)) && 48 (wps->dev_pw_id == wps->wps->ap_nfc_dev_pw_id || 49 wps->wps->ap_nfc_dh_pubkey)) { 50 wpa_printf(MSG_DEBUG, "WPS: Using NFC password token DH keys"); 51 if (wps->wps->ap_nfc_dh_privkey == NULL) { 52 wpa_printf(MSG_DEBUG, 53 "WPS: wps->wps->ap_nfc_dh_privkey == NULL"); 54 return -1; 55 } 56 if (wps->wps->ap_nfc_dh_pubkey == NULL) { 57 wpa_printf(MSG_DEBUG, 58 "WPS: wps->wps->ap_nfc_dh_pubkey == NULL"); 59 return -1; 60 } 61 wps->dh_privkey = wpabuf_dup(wps->wps->ap_nfc_dh_privkey); 62 pubkey = wpabuf_dup(wps->wps->ap_nfc_dh_pubkey); 63 wps->dh_ctx = dh5_init_fixed(wps->dh_privkey, pubkey); 64#endif /* CONFIG_WPS_NFC */ 65 } else { 66 wpa_printf(MSG_DEBUG, "WPS: Generate new DH keys"); 67 dh5_free(wps->dh_ctx); 68 wps->dh_ctx = dh5_init(&wps->dh_privkey, &pubkey); 69 pubkey = wpabuf_zeropad(pubkey, 192); 70 } 71 if (wps->dh_ctx == NULL || wps->dh_privkey == NULL || pubkey == NULL) { 72 wpa_printf(MSG_DEBUG, "WPS: Failed to initialize " 73 "Diffie-Hellman handshake"); 74 wpabuf_free(pubkey); 75 return -1; 76 } 77 wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH Private Key", wps->dh_privkey); 78 wpa_hexdump_buf(MSG_DEBUG, "WPS: DH own Public Key", pubkey); 79 80 wpabuf_put_be16(msg, ATTR_PUBLIC_KEY); 81 wpabuf_put_be16(msg, wpabuf_len(pubkey)); 82 wpabuf_put_buf(msg, pubkey); 83 84 if (wps->registrar) { 85 wpabuf_free(wps->dh_pubkey_r); 86 wps->dh_pubkey_r = pubkey; 87 } else { 88 wpabuf_free(wps->dh_pubkey_e); 89 wps->dh_pubkey_e = pubkey; 90 } 91 92 return 0; 93} 94 95 96int wps_build_req_type(struct wpabuf *msg, enum wps_request_type type) 97{ 98 wpa_printf(MSG_DEBUG, "WPS: * Request Type"); 99 wpabuf_put_be16(msg, ATTR_REQUEST_TYPE); 100 wpabuf_put_be16(msg, 1); 101 wpabuf_put_u8(msg, type); 102 return 0; 103} 104 105 106int wps_build_resp_type(struct wpabuf *msg, enum wps_response_type type) 107{ 108 wpa_printf(MSG_DEBUG, "WPS: * Response Type (%d)", type); 109 wpabuf_put_be16(msg, ATTR_RESPONSE_TYPE); 110 wpabuf_put_be16(msg, 1); 111 wpabuf_put_u8(msg, type); 112 return 0; 113} 114 115 116int wps_build_config_methods(struct wpabuf *msg, u16 methods) 117{ 118 wpa_printf(MSG_DEBUG, "WPS: * Config Methods (%x)", methods); 119 wpabuf_put_be16(msg, ATTR_CONFIG_METHODS); 120 wpabuf_put_be16(msg, 2); 121 wpabuf_put_be16(msg, methods); 122 return 0; 123} 124 125 126int wps_build_uuid_e(struct wpabuf *msg, const u8 *uuid) 127{ 128 if (wpabuf_tailroom(msg) < 4 + WPS_UUID_LEN) 129 return -1; 130 wpa_printf(MSG_DEBUG, "WPS: * UUID-E"); 131 wpabuf_put_be16(msg, ATTR_UUID_E); 132 wpabuf_put_be16(msg, WPS_UUID_LEN); 133 wpabuf_put_data(msg, uuid, WPS_UUID_LEN); 134 return 0; 135} 136 137 138int wps_build_dev_password_id(struct wpabuf *msg, u16 id) 139{ 140 wpa_printf(MSG_DEBUG, "WPS: * Device Password ID (%d)", id); 141 wpabuf_put_be16(msg, ATTR_DEV_PASSWORD_ID); 142 wpabuf_put_be16(msg, 2); 143 wpabuf_put_be16(msg, id); 144 return 0; 145} 146 147 148int wps_build_config_error(struct wpabuf *msg, u16 err) 149{ 150 wpa_printf(MSG_DEBUG, "WPS: * Configuration Error (%d)", err); 151 wpabuf_put_be16(msg, ATTR_CONFIG_ERROR); 152 wpabuf_put_be16(msg, 2); 153 wpabuf_put_be16(msg, err); 154 return 0; 155} 156 157 158int wps_build_authenticator(struct wps_data *wps, struct wpabuf *msg) 159{ 160 u8 hash[SHA256_MAC_LEN]; 161 const u8 *addr[2]; 162 size_t len[2]; 163 164 if (wps->last_msg == NULL) { 165 wpa_printf(MSG_DEBUG, "WPS: Last message not available for " 166 "building authenticator"); 167 return -1; 168 } 169 170 /* Authenticator = HMAC-SHA256_AuthKey(M_prev || M_curr*) 171 * (M_curr* is M_curr without the Authenticator attribute) 172 */ 173 addr[0] = wpabuf_head(wps->last_msg); 174 len[0] = wpabuf_len(wps->last_msg); 175 addr[1] = wpabuf_head(msg); 176 len[1] = wpabuf_len(msg); 177 hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 2, addr, len, hash); 178 179 wpa_printf(MSG_DEBUG, "WPS: * Authenticator"); 180 wpabuf_put_be16(msg, ATTR_AUTHENTICATOR); 181 wpabuf_put_be16(msg, WPS_AUTHENTICATOR_LEN); 182 wpabuf_put_data(msg, hash, WPS_AUTHENTICATOR_LEN); 183 184 return 0; 185} 186 187 188int wps_build_version(struct wpabuf *msg) 189{ 190 /* 191 * Note: This attribute is deprecated and set to hardcoded 0x10 for 192 * backwards compatibility reasons. The real version negotiation is 193 * done with Version2. 194 */ 195 if (wpabuf_tailroom(msg) < 5) 196 return -1; 197 wpa_printf(MSG_DEBUG, "WPS: * Version (hardcoded 0x10)"); 198 wpabuf_put_be16(msg, ATTR_VERSION); 199 wpabuf_put_be16(msg, 1); 200 wpabuf_put_u8(msg, 0x10); 201 return 0; 202} 203 204 205int wps_build_wfa_ext(struct wpabuf *msg, int req_to_enroll, 206 const u8 *auth_macs, size_t auth_macs_count) 207{ 208#ifdef CONFIG_WPS2 209 u8 *len; 210 211#ifdef CONFIG_WPS_TESTING 212 if (WPS_VERSION == 0x10) 213 return 0; 214#endif /* CONFIG_WPS_TESTING */ 215 216 if (wpabuf_tailroom(msg) < 217 7 + 3 + (req_to_enroll ? 3 : 0) + 218 (auth_macs ? 2 + auth_macs_count * ETH_ALEN : 0)) 219 return -1; 220 wpabuf_put_be16(msg, ATTR_VENDOR_EXT); 221 len = wpabuf_put(msg, 2); /* to be filled */ 222 wpabuf_put_be24(msg, WPS_VENDOR_ID_WFA); 223 224 wpa_printf(MSG_DEBUG, "WPS: * Version2 (0x%x)", WPS_VERSION); 225 wpabuf_put_u8(msg, WFA_ELEM_VERSION2); 226 wpabuf_put_u8(msg, 1); 227 wpabuf_put_u8(msg, WPS_VERSION); 228 229 if (req_to_enroll) { 230 wpa_printf(MSG_DEBUG, "WPS: * Request to Enroll (1)"); 231 wpabuf_put_u8(msg, WFA_ELEM_REQUEST_TO_ENROLL); 232 wpabuf_put_u8(msg, 1); 233 wpabuf_put_u8(msg, 1); 234 } 235 236 if (auth_macs && auth_macs_count) { 237 size_t i; 238 wpa_printf(MSG_DEBUG, "WPS: * AuthorizedMACs (count=%d)", 239 (int) auth_macs_count); 240 wpabuf_put_u8(msg, WFA_ELEM_AUTHORIZEDMACS); 241 wpabuf_put_u8(msg, auth_macs_count * ETH_ALEN); 242 wpabuf_put_data(msg, auth_macs, auth_macs_count * ETH_ALEN); 243 for (i = 0; i < auth_macs_count; i++) 244 wpa_printf(MSG_DEBUG, "WPS: AuthorizedMAC: " MACSTR, 245 MAC2STR(&auth_macs[i * ETH_ALEN])); 246 } 247 248 WPA_PUT_BE16(len, (u8 *) wpabuf_put(msg, 0) - len - 2); 249#endif /* CONFIG_WPS2 */ 250 251#ifdef CONFIG_WPS_TESTING 252 if (WPS_VERSION > 0x20) { 253 if (wpabuf_tailroom(msg) < 5) 254 return -1; 255 wpa_printf(MSG_DEBUG, "WPS: * Extensibility Testing - extra " 256 "attribute"); 257 wpabuf_put_be16(msg, ATTR_EXTENSIBILITY_TEST); 258 wpabuf_put_be16(msg, 1); 259 wpabuf_put_u8(msg, 42); 260 } 261#endif /* CONFIG_WPS_TESTING */ 262 return 0; 263} 264 265 266int wps_build_msg_type(struct wpabuf *msg, enum wps_msg_type msg_type) 267{ 268 wpa_printf(MSG_DEBUG, "WPS: * Message Type (%d)", msg_type); 269 wpabuf_put_be16(msg, ATTR_MSG_TYPE); 270 wpabuf_put_be16(msg, 1); 271 wpabuf_put_u8(msg, msg_type); 272 return 0; 273} 274 275 276int wps_build_enrollee_nonce(struct wps_data *wps, struct wpabuf *msg) 277{ 278 wpa_printf(MSG_DEBUG, "WPS: * Enrollee Nonce"); 279 wpabuf_put_be16(msg, ATTR_ENROLLEE_NONCE); 280 wpabuf_put_be16(msg, WPS_NONCE_LEN); 281 wpabuf_put_data(msg, wps->nonce_e, WPS_NONCE_LEN); 282 return 0; 283} 284 285 286int wps_build_registrar_nonce(struct wps_data *wps, struct wpabuf *msg) 287{ 288 wpa_printf(MSG_DEBUG, "WPS: * Registrar Nonce"); 289 wpabuf_put_be16(msg, ATTR_REGISTRAR_NONCE); 290 wpabuf_put_be16(msg, WPS_NONCE_LEN); 291 wpabuf_put_data(msg, wps->nonce_r, WPS_NONCE_LEN); 292 return 0; 293} 294 295 296int wps_build_auth_type_flags(struct wps_data *wps, struct wpabuf *msg) 297{ 298 u16 auth_types = WPS_AUTH_TYPES; 299 /* WPA/WPA2-Enterprise enrollment not supported through WPS */ 300 auth_types &= ~WPS_AUTH_WPA; 301 auth_types &= ~WPS_AUTH_WPA2; 302#ifdef CONFIG_WPS2 303 auth_types &= ~WPS_AUTH_SHARED; 304#endif /* CONFIG_WPS2 */ 305 wpa_printf(MSG_DEBUG, "WPS: * Authentication Type Flags"); 306 wpabuf_put_be16(msg, ATTR_AUTH_TYPE_FLAGS); 307 wpabuf_put_be16(msg, 2); 308 wpabuf_put_be16(msg, auth_types); 309 return 0; 310} 311 312 313int wps_build_encr_type_flags(struct wps_data *wps, struct wpabuf *msg) 314{ 315 u16 encr_types = WPS_ENCR_TYPES; 316#ifdef CONFIG_WPS2 317 encr_types &= ~WPS_ENCR_WEP; 318#endif /* CONFIG_WPS2 */ 319 wpa_printf(MSG_DEBUG, "WPS: * Encryption Type Flags"); 320 wpabuf_put_be16(msg, ATTR_ENCR_TYPE_FLAGS); 321 wpabuf_put_be16(msg, 2); 322 wpabuf_put_be16(msg, encr_types); 323 return 0; 324} 325 326 327int wps_build_conn_type_flags(struct wps_data *wps, struct wpabuf *msg) 328{ 329 wpa_printf(MSG_DEBUG, "WPS: * Connection Type Flags"); 330 wpabuf_put_be16(msg, ATTR_CONN_TYPE_FLAGS); 331 wpabuf_put_be16(msg, 1); 332 wpabuf_put_u8(msg, WPS_CONN_ESS); 333 return 0; 334} 335 336 337int wps_build_assoc_state(struct wps_data *wps, struct wpabuf *msg) 338{ 339 wpa_printf(MSG_DEBUG, "WPS: * Association State"); 340 wpabuf_put_be16(msg, ATTR_ASSOC_STATE); 341 wpabuf_put_be16(msg, 2); 342 wpabuf_put_be16(msg, WPS_ASSOC_NOT_ASSOC); 343 return 0; 344} 345 346 347int wps_build_key_wrap_auth(struct wps_data *wps, struct wpabuf *msg) 348{ 349 u8 hash[SHA256_MAC_LEN]; 350 351 wpa_printf(MSG_DEBUG, "WPS: * Key Wrap Authenticator"); 352 hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, wpabuf_head(msg), 353 wpabuf_len(msg), hash); 354 355 wpabuf_put_be16(msg, ATTR_KEY_WRAP_AUTH); 356 wpabuf_put_be16(msg, WPS_KWA_LEN); 357 wpabuf_put_data(msg, hash, WPS_KWA_LEN); 358 return 0; 359} 360 361 362int wps_build_encr_settings(struct wps_data *wps, struct wpabuf *msg, 363 struct wpabuf *plain) 364{ 365 size_t pad_len; 366 const size_t block_size = 16; 367 u8 *iv, *data; 368 369 wpa_printf(MSG_DEBUG, "WPS: * Encrypted Settings"); 370 371 /* PKCS#5 v2.0 pad */ 372 pad_len = block_size - wpabuf_len(plain) % block_size; 373 os_memset(wpabuf_put(plain, pad_len), pad_len, pad_len); 374 375 wpabuf_put_be16(msg, ATTR_ENCR_SETTINGS); 376 wpabuf_put_be16(msg, block_size + wpabuf_len(plain)); 377 378 iv = wpabuf_put(msg, block_size); 379 if (random_get_bytes(iv, block_size) < 0) 380 return -1; 381 382 data = wpabuf_put(msg, 0); 383 wpabuf_put_buf(msg, plain); 384 if (aes_128_cbc_encrypt(wps->keywrapkey, iv, data, wpabuf_len(plain))) 385 return -1; 386 387 return 0; 388} 389 390 391#ifdef CONFIG_WPS_OOB 392int wps_build_oob_dev_pw(struct wpabuf *msg, u16 dev_pw_id, 393 const struct wpabuf *pubkey, const u8 *dev_pw, 394 size_t dev_pw_len) 395{ 396 size_t hash_len; 397 const u8 *addr[1]; 398 u8 pubkey_hash[WPS_HASH_LEN]; 399 400 wpa_printf(MSG_DEBUG, "WPS: * OOB Device Password (dev_pw_id=%u)", 401 dev_pw_id); 402 addr[0] = wpabuf_head(pubkey); 403 hash_len = wpabuf_len(pubkey); 404 sha256_vector(1, addr, &hash_len, pubkey_hash); 405#ifdef CONFIG_WPS_TESTING 406 if (wps_corrupt_pkhash) { 407 wpa_hexdump(MSG_DEBUG, "WPS: Real Public Key Hash", 408 pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN); 409 wpa_printf(MSG_INFO, "WPS: Testing - corrupt public key hash"); 410 pubkey_hash[WPS_OOB_PUBKEY_HASH_LEN - 2]++; 411 } 412#endif /* CONFIG_WPS_TESTING */ 413 414 wpabuf_put_be16(msg, ATTR_OOB_DEVICE_PASSWORD); 415 wpabuf_put_be16(msg, WPS_OOB_PUBKEY_HASH_LEN + 2 + dev_pw_len); 416 wpa_hexdump(MSG_DEBUG, "WPS: Public Key Hash", 417 pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN); 418 wpabuf_put_data(msg, pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN); 419 wpabuf_put_be16(msg, dev_pw_id); 420 if (dev_pw) { 421 wpa_hexdump_key(MSG_DEBUG, "WPS: OOB Device Password", 422 dev_pw, dev_pw_len); 423 wpabuf_put_data(msg, dev_pw, dev_pw_len); 424 } 425 426 return 0; 427} 428#endif /* CONFIG_WPS_OOB */ 429 430 431/* Encapsulate WPS IE data with one (or more, if needed) IE headers */ 432struct wpabuf * wps_ie_encapsulate(struct wpabuf *data) 433{ 434 struct wpabuf *ie; 435 const u8 *pos, *end; 436 437 ie = wpabuf_alloc(wpabuf_len(data) + 100); 438 if (ie == NULL) { 439 wpabuf_free(data); 440 return NULL; 441 } 442 443 pos = wpabuf_head(data); 444 end = pos + wpabuf_len(data); 445 446 while (end > pos) { 447 size_t frag_len = end - pos; 448 if (frag_len > 251) 449 frag_len = 251; 450 wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC); 451 wpabuf_put_u8(ie, 4 + frag_len); 452 wpabuf_put_be32(ie, WPS_DEV_OUI_WFA); 453 wpabuf_put_data(ie, pos, frag_len); 454 pos += frag_len; 455 } 456 457 wpabuf_free(data); 458 459 return ie; 460} 461 462 463int wps_build_mac_addr(struct wpabuf *msg, const u8 *addr) 464{ 465 wpa_printf(MSG_DEBUG, "WPS: * MAC Address (" MACSTR ")", 466 MAC2STR(addr)); 467 wpabuf_put_be16(msg, ATTR_MAC_ADDR); 468 wpabuf_put_be16(msg, ETH_ALEN); 469 wpabuf_put_data(msg, addr, ETH_ALEN); 470 return 0; 471} 472 473 474int wps_build_rf_bands_attr(struct wpabuf *msg, u8 rf_bands) 475{ 476 wpa_printf(MSG_DEBUG, "WPS: * RF Bands (%x)", rf_bands); 477 wpabuf_put_be16(msg, ATTR_RF_BANDS); 478 wpabuf_put_be16(msg, 1); 479 wpabuf_put_u8(msg, rf_bands); 480 return 0; 481} 482 483 484int wps_build_ap_channel(struct wpabuf *msg, u16 ap_channel) 485{ 486 wpa_printf(MSG_DEBUG, "WPS: * AP Channel (%u)", ap_channel); 487 wpabuf_put_be16(msg, ATTR_AP_CHANNEL); 488 wpabuf_put_be16(msg, 2); 489 wpabuf_put_be16(msg, ap_channel); 490 return 0; 491} 492