wps_attr_build.c revision 68d0e3ed07847339aedfac8e02f50db68c702e52
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 && wps->wps->ap && 42 wps->dev_pw_id == wps->wps->ap_nfc_dev_pw_id) { 43 wpa_printf(MSG_DEBUG, "WPS: Using NFC password token DH keys"); 44 if (wps->wps->ap_nfc_dh_privkey == NULL) { 45 wpa_printf(MSG_DEBUG, 46 "WPS: wps->wps->ap_nfc_dh_privkey == NULL"); 47 return -1; 48 } 49 if (wps->wps->ap_nfc_dh_pubkey == NULL) { 50 wpa_printf(MSG_DEBUG, 51 "WPS: wps->wps->ap_nfc_dh_pubkey == NULL"); 52 return -1; 53 } 54 wps->dh_privkey = wpabuf_dup(wps->wps->ap_nfc_dh_privkey); 55 pubkey = wpabuf_dup(wps->wps->ap_nfc_dh_pubkey); 56 wps->dh_ctx = dh5_init_fixed(wps->dh_privkey, pubkey); 57#endif /* CONFIG_WPS_NFC */ 58 } else { 59 wpa_printf(MSG_DEBUG, "WPS: Generate new DH keys"); 60 dh5_free(wps->dh_ctx); 61 wps->dh_ctx = dh5_init(&wps->dh_privkey, &pubkey); 62 pubkey = wpabuf_zeropad(pubkey, 192); 63 } 64 if (wps->dh_ctx == NULL || wps->dh_privkey == NULL || pubkey == NULL) { 65 wpa_printf(MSG_DEBUG, "WPS: Failed to initialize " 66 "Diffie-Hellman handshake"); 67 wpabuf_free(pubkey); 68 return -1; 69 } 70 wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH Private Key", wps->dh_privkey); 71 wpa_hexdump_buf(MSG_DEBUG, "WPS: DH own Public Key", pubkey); 72 73 wpabuf_put_be16(msg, ATTR_PUBLIC_KEY); 74 wpabuf_put_be16(msg, wpabuf_len(pubkey)); 75 wpabuf_put_buf(msg, pubkey); 76 77 if (wps->registrar) { 78 wpabuf_free(wps->dh_pubkey_r); 79 wps->dh_pubkey_r = pubkey; 80 } else { 81 wpabuf_free(wps->dh_pubkey_e); 82 wps->dh_pubkey_e = pubkey; 83 } 84 85 return 0; 86} 87 88 89int wps_build_req_type(struct wpabuf *msg, enum wps_request_type type) 90{ 91 wpa_printf(MSG_DEBUG, "WPS: * Request Type"); 92 wpabuf_put_be16(msg, ATTR_REQUEST_TYPE); 93 wpabuf_put_be16(msg, 1); 94 wpabuf_put_u8(msg, type); 95 return 0; 96} 97 98 99int wps_build_resp_type(struct wpabuf *msg, enum wps_response_type type) 100{ 101 wpa_printf(MSG_DEBUG, "WPS: * Response Type (%d)", type); 102 wpabuf_put_be16(msg, ATTR_RESPONSE_TYPE); 103 wpabuf_put_be16(msg, 1); 104 wpabuf_put_u8(msg, type); 105 return 0; 106} 107 108 109int wps_build_config_methods(struct wpabuf *msg, u16 methods) 110{ 111 wpa_printf(MSG_DEBUG, "WPS: * Config Methods (%x)", methods); 112 wpabuf_put_be16(msg, ATTR_CONFIG_METHODS); 113 wpabuf_put_be16(msg, 2); 114 wpabuf_put_be16(msg, methods); 115 return 0; 116} 117 118 119int wps_build_uuid_e(struct wpabuf *msg, const u8 *uuid) 120{ 121 if (wpabuf_tailroom(msg) < 4 + WPS_UUID_LEN) 122 return -1; 123 wpa_printf(MSG_DEBUG, "WPS: * UUID-E"); 124 wpabuf_put_be16(msg, ATTR_UUID_E); 125 wpabuf_put_be16(msg, WPS_UUID_LEN); 126 wpabuf_put_data(msg, uuid, WPS_UUID_LEN); 127 return 0; 128} 129 130 131int wps_build_dev_password_id(struct wpabuf *msg, u16 id) 132{ 133 wpa_printf(MSG_DEBUG, "WPS: * Device Password ID (%d)", id); 134 wpabuf_put_be16(msg, ATTR_DEV_PASSWORD_ID); 135 wpabuf_put_be16(msg, 2); 136 wpabuf_put_be16(msg, id); 137 return 0; 138} 139 140 141int wps_build_config_error(struct wpabuf *msg, u16 err) 142{ 143 wpa_printf(MSG_DEBUG, "WPS: * Configuration Error (%d)", err); 144 wpabuf_put_be16(msg, ATTR_CONFIG_ERROR); 145 wpabuf_put_be16(msg, 2); 146 wpabuf_put_be16(msg, err); 147 return 0; 148} 149 150 151int wps_build_authenticator(struct wps_data *wps, struct wpabuf *msg) 152{ 153 u8 hash[SHA256_MAC_LEN]; 154 const u8 *addr[2]; 155 size_t len[2]; 156 157 if (wps->last_msg == NULL) { 158 wpa_printf(MSG_DEBUG, "WPS: Last message not available for " 159 "building authenticator"); 160 return -1; 161 } 162 163 /* Authenticator = HMAC-SHA256_AuthKey(M_prev || M_curr*) 164 * (M_curr* is M_curr without the Authenticator attribute) 165 */ 166 addr[0] = wpabuf_head(wps->last_msg); 167 len[0] = wpabuf_len(wps->last_msg); 168 addr[1] = wpabuf_head(msg); 169 len[1] = wpabuf_len(msg); 170 hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 2, addr, len, hash); 171 172 wpa_printf(MSG_DEBUG, "WPS: * Authenticator"); 173 wpabuf_put_be16(msg, ATTR_AUTHENTICATOR); 174 wpabuf_put_be16(msg, WPS_AUTHENTICATOR_LEN); 175 wpabuf_put_data(msg, hash, WPS_AUTHENTICATOR_LEN); 176 177 return 0; 178} 179 180 181int wps_build_version(struct wpabuf *msg) 182{ 183 /* 184 * Note: This attribute is deprecated and set to hardcoded 0x10 for 185 * backwards compatibility reasons. The real version negotiation is 186 * done with Version2. 187 */ 188 if (wpabuf_tailroom(msg) < 5) 189 return -1; 190 wpa_printf(MSG_DEBUG, "WPS: * Version (hardcoded 0x10)"); 191 wpabuf_put_be16(msg, ATTR_VERSION); 192 wpabuf_put_be16(msg, 1); 193 wpabuf_put_u8(msg, 0x10); 194 return 0; 195} 196 197 198int wps_build_wfa_ext(struct wpabuf *msg, int req_to_enroll, 199 const u8 *auth_macs, size_t auth_macs_count) 200{ 201#ifdef CONFIG_WPS2 202 u8 *len; 203 204 if (wpabuf_tailroom(msg) < 205 7 + 3 + (req_to_enroll ? 3 : 0) + 206 (auth_macs ? 2 + auth_macs_count * ETH_ALEN : 0)) 207 return -1; 208 wpabuf_put_be16(msg, ATTR_VENDOR_EXT); 209 len = wpabuf_put(msg, 2); /* to be filled */ 210 wpabuf_put_be24(msg, WPS_VENDOR_ID_WFA); 211 212 wpa_printf(MSG_DEBUG, "WPS: * Version2 (0x%x)", WPS_VERSION); 213 wpabuf_put_u8(msg, WFA_ELEM_VERSION2); 214 wpabuf_put_u8(msg, 1); 215 wpabuf_put_u8(msg, WPS_VERSION); 216 217 if (req_to_enroll) { 218 wpa_printf(MSG_DEBUG, "WPS: * Request to Enroll (1)"); 219 wpabuf_put_u8(msg, WFA_ELEM_REQUEST_TO_ENROLL); 220 wpabuf_put_u8(msg, 1); 221 wpabuf_put_u8(msg, 1); 222 } 223 224 if (auth_macs && auth_macs_count) { 225 size_t i; 226 wpa_printf(MSG_DEBUG, "WPS: * AuthorizedMACs (count=%d)", 227 (int) auth_macs_count); 228 wpabuf_put_u8(msg, WFA_ELEM_AUTHORIZEDMACS); 229 wpabuf_put_u8(msg, auth_macs_count * ETH_ALEN); 230 wpabuf_put_data(msg, auth_macs, auth_macs_count * ETH_ALEN); 231 for (i = 0; i < auth_macs_count; i++) 232 wpa_printf(MSG_DEBUG, "WPS: AuthorizedMAC: " MACSTR, 233 MAC2STR(&auth_macs[i * ETH_ALEN])); 234 } 235 236 WPA_PUT_BE16(len, (u8 *) wpabuf_put(msg, 0) - len - 2); 237#endif /* CONFIG_WPS2 */ 238 239#ifdef CONFIG_WPS_TESTING 240 if (WPS_VERSION > 0x20) { 241 if (wpabuf_tailroom(msg) < 5) 242 return -1; 243 wpa_printf(MSG_DEBUG, "WPS: * Extensibility Testing - extra " 244 "attribute"); 245 wpabuf_put_be16(msg, ATTR_EXTENSIBILITY_TEST); 246 wpabuf_put_be16(msg, 1); 247 wpabuf_put_u8(msg, 42); 248 } 249#endif /* CONFIG_WPS_TESTING */ 250 return 0; 251} 252 253 254int wps_build_msg_type(struct wpabuf *msg, enum wps_msg_type msg_type) 255{ 256 wpa_printf(MSG_DEBUG, "WPS: * Message Type (%d)", msg_type); 257 wpabuf_put_be16(msg, ATTR_MSG_TYPE); 258 wpabuf_put_be16(msg, 1); 259 wpabuf_put_u8(msg, msg_type); 260 return 0; 261} 262 263 264int wps_build_enrollee_nonce(struct wps_data *wps, struct wpabuf *msg) 265{ 266 wpa_printf(MSG_DEBUG, "WPS: * Enrollee Nonce"); 267 wpabuf_put_be16(msg, ATTR_ENROLLEE_NONCE); 268 wpabuf_put_be16(msg, WPS_NONCE_LEN); 269 wpabuf_put_data(msg, wps->nonce_e, WPS_NONCE_LEN); 270 return 0; 271} 272 273 274int wps_build_registrar_nonce(struct wps_data *wps, struct wpabuf *msg) 275{ 276 wpa_printf(MSG_DEBUG, "WPS: * Registrar Nonce"); 277 wpabuf_put_be16(msg, ATTR_REGISTRAR_NONCE); 278 wpabuf_put_be16(msg, WPS_NONCE_LEN); 279 wpabuf_put_data(msg, wps->nonce_r, WPS_NONCE_LEN); 280 return 0; 281} 282 283 284int wps_build_auth_type_flags(struct wps_data *wps, struct wpabuf *msg) 285{ 286 u16 auth_types = WPS_AUTH_TYPES; 287#ifdef CONFIG_WPS2 288 auth_types &= ~WPS_AUTH_SHARED; 289#endif /* CONFIG_WPS2 */ 290 wpa_printf(MSG_DEBUG, "WPS: * Authentication Type Flags"); 291 wpabuf_put_be16(msg, ATTR_AUTH_TYPE_FLAGS); 292 wpabuf_put_be16(msg, 2); 293 wpabuf_put_be16(msg, auth_types); 294 return 0; 295} 296 297 298int wps_build_encr_type_flags(struct wps_data *wps, struct wpabuf *msg) 299{ 300 u16 encr_types = WPS_ENCR_TYPES; 301#ifdef CONFIG_WPS2 302 encr_types &= ~WPS_ENCR_WEP; 303#endif /* CONFIG_WPS2 */ 304 wpa_printf(MSG_DEBUG, "WPS: * Encryption Type Flags"); 305 wpabuf_put_be16(msg, ATTR_ENCR_TYPE_FLAGS); 306 wpabuf_put_be16(msg, 2); 307 wpabuf_put_be16(msg, encr_types); 308 return 0; 309} 310 311 312int wps_build_conn_type_flags(struct wps_data *wps, struct wpabuf *msg) 313{ 314 wpa_printf(MSG_DEBUG, "WPS: * Connection Type Flags"); 315 wpabuf_put_be16(msg, ATTR_CONN_TYPE_FLAGS); 316 wpabuf_put_be16(msg, 1); 317 wpabuf_put_u8(msg, WPS_CONN_ESS); 318 return 0; 319} 320 321 322int wps_build_assoc_state(struct wps_data *wps, struct wpabuf *msg) 323{ 324 wpa_printf(MSG_DEBUG, "WPS: * Association State"); 325 wpabuf_put_be16(msg, ATTR_ASSOC_STATE); 326 wpabuf_put_be16(msg, 2); 327 wpabuf_put_be16(msg, WPS_ASSOC_NOT_ASSOC); 328 return 0; 329} 330 331 332int wps_build_key_wrap_auth(struct wps_data *wps, struct wpabuf *msg) 333{ 334 u8 hash[SHA256_MAC_LEN]; 335 336 wpa_printf(MSG_DEBUG, "WPS: * Key Wrap Authenticator"); 337 hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, wpabuf_head(msg), 338 wpabuf_len(msg), hash); 339 340 wpabuf_put_be16(msg, ATTR_KEY_WRAP_AUTH); 341 wpabuf_put_be16(msg, WPS_KWA_LEN); 342 wpabuf_put_data(msg, hash, WPS_KWA_LEN); 343 return 0; 344} 345 346 347int wps_build_encr_settings(struct wps_data *wps, struct wpabuf *msg, 348 struct wpabuf *plain) 349{ 350 size_t pad_len; 351 const size_t block_size = 16; 352 u8 *iv, *data; 353 354 wpa_printf(MSG_DEBUG, "WPS: * Encrypted Settings"); 355 356 /* PKCS#5 v2.0 pad */ 357 pad_len = block_size - wpabuf_len(plain) % block_size; 358 os_memset(wpabuf_put(plain, pad_len), pad_len, pad_len); 359 360 wpabuf_put_be16(msg, ATTR_ENCR_SETTINGS); 361 wpabuf_put_be16(msg, block_size + wpabuf_len(plain)); 362 363 iv = wpabuf_put(msg, block_size); 364 if (random_get_bytes(iv, block_size) < 0) 365 return -1; 366 367 data = wpabuf_put(msg, 0); 368 wpabuf_put_buf(msg, plain); 369 if (aes_128_cbc_encrypt(wps->keywrapkey, iv, data, wpabuf_len(plain))) 370 return -1; 371 372 return 0; 373} 374 375 376#ifdef CONFIG_WPS_OOB 377int wps_build_oob_dev_pw(struct wpabuf *msg, u16 dev_pw_id, 378 const struct wpabuf *pubkey, const u8 *dev_pw, 379 size_t dev_pw_len) 380{ 381 size_t hash_len; 382 const u8 *addr[1]; 383 u8 pubkey_hash[WPS_HASH_LEN]; 384 385 addr[0] = wpabuf_head(pubkey); 386 hash_len = wpabuf_len(pubkey); 387 sha256_vector(1, addr, &hash_len, pubkey_hash); 388 389 wpabuf_put_be16(msg, ATTR_OOB_DEVICE_PASSWORD); 390 wpabuf_put_be16(msg, WPS_OOB_PUBKEY_HASH_LEN + 2 + dev_pw_len); 391 wpabuf_put_data(msg, pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN); 392 wpabuf_put_be16(msg, dev_pw_id); 393 wpabuf_put_data(msg, dev_pw, dev_pw_len); 394 395 return 0; 396} 397#endif /* CONFIG_WPS_OOB */ 398 399 400/* Encapsulate WPS IE data with one (or more, if needed) IE headers */ 401struct wpabuf * wps_ie_encapsulate(struct wpabuf *data) 402{ 403 struct wpabuf *ie; 404 const u8 *pos, *end; 405 406 ie = wpabuf_alloc(wpabuf_len(data) + 100); 407 if (ie == NULL) { 408 wpabuf_free(data); 409 return NULL; 410 } 411 412 pos = wpabuf_head(data); 413 end = pos + wpabuf_len(data); 414 415 while (end > pos) { 416 size_t frag_len = end - pos; 417 if (frag_len > 251) 418 frag_len = 251; 419 wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC); 420 wpabuf_put_u8(ie, 4 + frag_len); 421 wpabuf_put_be32(ie, WPS_DEV_OUI_WFA); 422 wpabuf_put_data(ie, pos, frag_len); 423 pos += frag_len; 424 } 425 426 wpabuf_free(data); 427 428 return ie; 429} 430 431 432int wps_build_mac_addr(struct wpabuf *msg, const u8 *addr) 433{ 434 wpa_printf(MSG_DEBUG, "WPS: * MAC Address (" MACSTR ")", 435 MAC2STR(addr)); 436 wpabuf_put_be16(msg, ATTR_MAC_ADDR); 437 wpabuf_put_be16(msg, ETH_ALEN); 438 wpabuf_put_data(msg, addr, ETH_ALEN); 439 return 0; 440} 441