1 /*
2 * Wi-Fi Protected Setup - attribute building
3 * Copyright (c) 2008-2016, 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
wps_build_public_key(struct wps_data * wps,struct wpabuf * msg)21 int wps_build_public_key(struct wps_data *wps, struct wpabuf *msg)
22 {
23 struct wpabuf *pubkey = NULL;
24
25 wpa_printf(MSG_DEBUG, "WPS: * Public Key");
26 wpabuf_clear_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 if (wps->dh_privkey && pubkey)
64 wps->dh_ctx = dh5_init_fixed(wps->dh_privkey, pubkey);
65 #endif /* CONFIG_WPS_NFC */
66 } else {
67 wpa_printf(MSG_DEBUG, "WPS: Generate new DH keys");
68 dh5_free(wps->dh_ctx);
69 wps->dh_ctx = dh5_init(&wps->dh_privkey, &pubkey);
70 pubkey = wpabuf_zeropad(pubkey, 192);
71 }
72 if (wps->dh_ctx == NULL || wps->dh_privkey == NULL || pubkey == NULL) {
73 wpa_printf(MSG_DEBUG, "WPS: Failed to initialize "
74 "Diffie-Hellman handshake");
75 wpabuf_free(pubkey);
76 return -1;
77 }
78 wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH Private Key", wps->dh_privkey);
79 wpa_hexdump_buf(MSG_DEBUG, "WPS: DH own Public Key", pubkey);
80
81 wpabuf_put_be16(msg, ATTR_PUBLIC_KEY);
82 wpabuf_put_be16(msg, wpabuf_len(pubkey));
83 wpabuf_put_buf(msg, pubkey);
84
85 if (wps->registrar) {
86 wpabuf_free(wps->dh_pubkey_r);
87 wps->dh_pubkey_r = pubkey;
88 } else {
89 wpabuf_free(wps->dh_pubkey_e);
90 wps->dh_pubkey_e = pubkey;
91 }
92
93 return 0;
94 }
95
96
wps_build_req_type(struct wpabuf * msg,enum wps_request_type type)97 int wps_build_req_type(struct wpabuf *msg, enum wps_request_type type)
98 {
99 wpa_printf(MSG_DEBUG, "WPS: * Request Type");
100 wpabuf_put_be16(msg, ATTR_REQUEST_TYPE);
101 wpabuf_put_be16(msg, 1);
102 wpabuf_put_u8(msg, type);
103 return 0;
104 }
105
106
wps_build_resp_type(struct wpabuf * msg,enum wps_response_type type)107 int wps_build_resp_type(struct wpabuf *msg, enum wps_response_type type)
108 {
109 wpa_printf(MSG_DEBUG, "WPS: * Response Type (%d)", type);
110 wpabuf_put_be16(msg, ATTR_RESPONSE_TYPE);
111 wpabuf_put_be16(msg, 1);
112 wpabuf_put_u8(msg, type);
113 return 0;
114 }
115
116
wps_build_config_methods(struct wpabuf * msg,u16 methods)117 int wps_build_config_methods(struct wpabuf *msg, u16 methods)
118 {
119 wpa_printf(MSG_DEBUG, "WPS: * Config Methods (%x)", methods);
120 wpabuf_put_be16(msg, ATTR_CONFIG_METHODS);
121 wpabuf_put_be16(msg, 2);
122 wpabuf_put_be16(msg, methods);
123 return 0;
124 }
125
126
wps_build_uuid_e(struct wpabuf * msg,const u8 * uuid)127 int wps_build_uuid_e(struct wpabuf *msg, const u8 *uuid)
128 {
129 if (wpabuf_tailroom(msg) < 4 + WPS_UUID_LEN)
130 return -1;
131 wpa_printf(MSG_DEBUG, "WPS: * UUID-E");
132 wpabuf_put_be16(msg, ATTR_UUID_E);
133 wpabuf_put_be16(msg, WPS_UUID_LEN);
134 wpabuf_put_data(msg, uuid, WPS_UUID_LEN);
135 return 0;
136 }
137
138
wps_build_dev_password_id(struct wpabuf * msg,u16 id)139 int wps_build_dev_password_id(struct wpabuf *msg, u16 id)
140 {
141 wpa_printf(MSG_DEBUG, "WPS: * Device Password ID (%d)", id);
142 wpabuf_put_be16(msg, ATTR_DEV_PASSWORD_ID);
143 wpabuf_put_be16(msg, 2);
144 wpabuf_put_be16(msg, id);
145 return 0;
146 }
147
148
wps_build_config_error(struct wpabuf * msg,u16 err)149 int wps_build_config_error(struct wpabuf *msg, u16 err)
150 {
151 wpa_printf(MSG_DEBUG, "WPS: * Configuration Error (%d)", err);
152 wpabuf_put_be16(msg, ATTR_CONFIG_ERROR);
153 wpabuf_put_be16(msg, 2);
154 wpabuf_put_be16(msg, err);
155 return 0;
156 }
157
158
wps_build_authenticator(struct wps_data * wps,struct wpabuf * msg)159 int wps_build_authenticator(struct wps_data *wps, struct wpabuf *msg)
160 {
161 u8 hash[SHA256_MAC_LEN];
162 const u8 *addr[2];
163 size_t len[2];
164
165 if (wps->last_msg == NULL) {
166 wpa_printf(MSG_DEBUG, "WPS: Last message not available for "
167 "building authenticator");
168 return -1;
169 }
170
171 /* Authenticator = HMAC-SHA256_AuthKey(M_prev || M_curr*)
172 * (M_curr* is M_curr without the Authenticator attribute)
173 */
174 addr[0] = wpabuf_head(wps->last_msg);
175 len[0] = wpabuf_len(wps->last_msg);
176 addr[1] = wpabuf_head(msg);
177 len[1] = wpabuf_len(msg);
178 hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 2, addr, len, hash);
179
180 wpa_printf(MSG_DEBUG, "WPS: * Authenticator");
181 wpabuf_put_be16(msg, ATTR_AUTHENTICATOR);
182 wpabuf_put_be16(msg, WPS_AUTHENTICATOR_LEN);
183 wpabuf_put_data(msg, hash, WPS_AUTHENTICATOR_LEN);
184
185 return 0;
186 }
187
188
wps_build_version(struct wpabuf * msg)189 int wps_build_version(struct wpabuf *msg)
190 {
191 /*
192 * Note: This attribute is deprecated and set to hardcoded 0x10 for
193 * backwards compatibility reasons. The real version negotiation is
194 * done with Version2.
195 */
196 if (wpabuf_tailroom(msg) < 5)
197 return -1;
198 wpa_printf(MSG_DEBUG, "WPS: * Version (hardcoded 0x10)");
199 wpabuf_put_be16(msg, ATTR_VERSION);
200 wpabuf_put_be16(msg, 1);
201 wpabuf_put_u8(msg, 0x10);
202 return 0;
203 }
204
205
wps_build_wfa_ext(struct wpabuf * msg,int req_to_enroll,const u8 * auth_macs,size_t auth_macs_count,u8 multi_ap_subelem)206 int wps_build_wfa_ext(struct wpabuf *msg, int req_to_enroll,
207 const u8 *auth_macs, size_t auth_macs_count,
208 u8 multi_ap_subelem)
209 {
210 u8 *len;
211
212 #ifdef CONFIG_WPS_TESTING
213 if (WPS_VERSION == 0x10)
214 return 0;
215 #endif /* CONFIG_WPS_TESTING */
216
217 if (wpabuf_tailroom(msg) <
218 7 + 3 + (req_to_enroll ? 3 : 0) +
219 (auth_macs ? 2 + auth_macs_count * ETH_ALEN : 0))
220 return -1;
221 wpabuf_put_be16(msg, ATTR_VENDOR_EXT);
222 len = wpabuf_put(msg, 2); /* to be filled */
223 wpabuf_put_be24(msg, WPS_VENDOR_ID_WFA);
224
225 wpa_printf(MSG_DEBUG, "WPS: * Version2 (0x%x)", WPS_VERSION);
226 wpabuf_put_u8(msg, WFA_ELEM_VERSION2);
227 wpabuf_put_u8(msg, 1);
228 wpabuf_put_u8(msg, WPS_VERSION);
229
230 if (req_to_enroll) {
231 wpa_printf(MSG_DEBUG, "WPS: * Request to Enroll (1)");
232 wpabuf_put_u8(msg, WFA_ELEM_REQUEST_TO_ENROLL);
233 wpabuf_put_u8(msg, 1);
234 wpabuf_put_u8(msg, 1);
235 }
236
237 if (auth_macs && auth_macs_count) {
238 size_t i;
239 wpa_printf(MSG_DEBUG, "WPS: * AuthorizedMACs (count=%d)",
240 (int) auth_macs_count);
241 wpabuf_put_u8(msg, WFA_ELEM_AUTHORIZEDMACS);
242 wpabuf_put_u8(msg, auth_macs_count * ETH_ALEN);
243 wpabuf_put_data(msg, auth_macs, auth_macs_count * ETH_ALEN);
244 for (i = 0; i < auth_macs_count; i++)
245 wpa_printf(MSG_DEBUG, "WPS: AuthorizedMAC: " MACSTR,
246 MAC2STR(&auth_macs[i * ETH_ALEN]));
247 }
248
249 if (multi_ap_subelem) {
250 wpa_printf(MSG_DEBUG, "WPS: * Multi-AP (0x%x)",
251 multi_ap_subelem);
252 wpabuf_put_u8(msg, WFA_ELEM_MULTI_AP);
253 wpabuf_put_u8(msg, 1); /* length */
254 wpabuf_put_u8(msg, multi_ap_subelem);
255 }
256
257 WPA_PUT_BE16(len, (u8 *) wpabuf_put(msg, 0) - len - 2);
258
259 #ifdef CONFIG_WPS_TESTING
260 if (WPS_VERSION > 0x20) {
261 if (wpabuf_tailroom(msg) < 5)
262 return -1;
263 wpa_printf(MSG_DEBUG, "WPS: * Extensibility Testing - extra "
264 "attribute");
265 wpabuf_put_be16(msg, ATTR_EXTENSIBILITY_TEST);
266 wpabuf_put_be16(msg, 1);
267 wpabuf_put_u8(msg, 42);
268 }
269 #endif /* CONFIG_WPS_TESTING */
270 return 0;
271 }
272
273
wps_build_msg_type(struct wpabuf * msg,enum wps_msg_type msg_type)274 int wps_build_msg_type(struct wpabuf *msg, enum wps_msg_type msg_type)
275 {
276 wpa_printf(MSG_DEBUG, "WPS: * Message Type (%d)", msg_type);
277 wpabuf_put_be16(msg, ATTR_MSG_TYPE);
278 wpabuf_put_be16(msg, 1);
279 wpabuf_put_u8(msg, msg_type);
280 return 0;
281 }
282
283
wps_build_enrollee_nonce(struct wps_data * wps,struct wpabuf * msg)284 int wps_build_enrollee_nonce(struct wps_data *wps, struct wpabuf *msg)
285 {
286 wpa_printf(MSG_DEBUG, "WPS: * Enrollee Nonce");
287 wpabuf_put_be16(msg, ATTR_ENROLLEE_NONCE);
288 wpabuf_put_be16(msg, WPS_NONCE_LEN);
289 wpabuf_put_data(msg, wps->nonce_e, WPS_NONCE_LEN);
290 return 0;
291 }
292
293
wps_build_registrar_nonce(struct wps_data * wps,struct wpabuf * msg)294 int wps_build_registrar_nonce(struct wps_data *wps, struct wpabuf *msg)
295 {
296 wpa_printf(MSG_DEBUG, "WPS: * Registrar Nonce");
297 wpabuf_put_be16(msg, ATTR_REGISTRAR_NONCE);
298 wpabuf_put_be16(msg, WPS_NONCE_LEN);
299 wpabuf_put_data(msg, wps->nonce_r, WPS_NONCE_LEN);
300 return 0;
301 }
302
303
wps_build_auth_type_flags(struct wps_data * wps,struct wpabuf * msg)304 int wps_build_auth_type_flags(struct wps_data *wps, struct wpabuf *msg)
305 {
306 u16 auth_types = WPS_AUTH_TYPES;
307 /* WPA/WPA2-Enterprise enrollment not supported through WPS */
308 auth_types &= ~WPS_AUTH_WPA;
309 auth_types &= ~WPS_AUTH_WPA2;
310 auth_types &= ~WPS_AUTH_SHARED;
311 #ifdef CONFIG_WPS_TESTING
312 if (wps_force_auth_types_in_use) {
313 wpa_printf(MSG_DEBUG,
314 "WPS: Testing - replace auth type 0x%x with 0x%x",
315 auth_types, wps_force_auth_types);
316 auth_types = wps_force_auth_types;
317 }
318 #endif /* CONFIG_WPS_TESTING */
319 wpa_printf(MSG_DEBUG, "WPS: * Authentication Type Flags (0x%x)",
320 auth_types);
321 wpabuf_put_be16(msg, ATTR_AUTH_TYPE_FLAGS);
322 wpabuf_put_be16(msg, 2);
323 wpabuf_put_be16(msg, auth_types);
324 return 0;
325 }
326
327
wps_build_encr_type_flags(struct wps_data * wps,struct wpabuf * msg)328 int wps_build_encr_type_flags(struct wps_data *wps, struct wpabuf *msg)
329 {
330 u16 encr_types = WPS_ENCR_TYPES;
331 encr_types &= ~WPS_ENCR_WEP;
332 #ifdef CONFIG_WPS_TESTING
333 if (wps_force_encr_types_in_use) {
334 wpa_printf(MSG_DEBUG,
335 "WPS: Testing - replace encr type 0x%x with 0x%x",
336 encr_types, wps_force_encr_types);
337 encr_types = wps_force_encr_types;
338 }
339 #endif /* CONFIG_WPS_TESTING */
340 wpa_printf(MSG_DEBUG, "WPS: * Encryption Type Flags (0x%x)",
341 encr_types);
342 wpabuf_put_be16(msg, ATTR_ENCR_TYPE_FLAGS);
343 wpabuf_put_be16(msg, 2);
344 wpabuf_put_be16(msg, encr_types);
345 return 0;
346 }
347
348
wps_build_conn_type_flags(struct wps_data * wps,struct wpabuf * msg)349 int wps_build_conn_type_flags(struct wps_data *wps, struct wpabuf *msg)
350 {
351 wpa_printf(MSG_DEBUG, "WPS: * Connection Type Flags");
352 wpabuf_put_be16(msg, ATTR_CONN_TYPE_FLAGS);
353 wpabuf_put_be16(msg, 1);
354 wpabuf_put_u8(msg, WPS_CONN_ESS);
355 return 0;
356 }
357
358
wps_build_assoc_state(struct wps_data * wps,struct wpabuf * msg)359 int wps_build_assoc_state(struct wps_data *wps, struct wpabuf *msg)
360 {
361 wpa_printf(MSG_DEBUG, "WPS: * Association State");
362 wpabuf_put_be16(msg, ATTR_ASSOC_STATE);
363 wpabuf_put_be16(msg, 2);
364 wpabuf_put_be16(msg, WPS_ASSOC_NOT_ASSOC);
365 return 0;
366 }
367
368
wps_build_key_wrap_auth(struct wps_data * wps,struct wpabuf * msg)369 int wps_build_key_wrap_auth(struct wps_data *wps, struct wpabuf *msg)
370 {
371 u8 hash[SHA256_MAC_LEN];
372
373 wpa_printf(MSG_DEBUG, "WPS: * Key Wrap Authenticator");
374 hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, wpabuf_head(msg),
375 wpabuf_len(msg), hash);
376
377 wpabuf_put_be16(msg, ATTR_KEY_WRAP_AUTH);
378 wpabuf_put_be16(msg, WPS_KWA_LEN);
379 wpabuf_put_data(msg, hash, WPS_KWA_LEN);
380 return 0;
381 }
382
383
wps_build_encr_settings(struct wps_data * wps,struct wpabuf * msg,struct wpabuf * plain)384 int wps_build_encr_settings(struct wps_data *wps, struct wpabuf *msg,
385 struct wpabuf *plain)
386 {
387 size_t pad_len;
388 const size_t block_size = 16;
389 u8 *iv, *data;
390
391 wpa_printf(MSG_DEBUG, "WPS: * Encrypted Settings");
392
393 /* PKCS#5 v2.0 pad */
394 pad_len = block_size - wpabuf_len(plain) % block_size;
395 os_memset(wpabuf_put(plain, pad_len), pad_len, pad_len);
396
397 wpabuf_put_be16(msg, ATTR_ENCR_SETTINGS);
398 wpabuf_put_be16(msg, block_size + wpabuf_len(plain));
399
400 iv = wpabuf_put(msg, block_size);
401 if (random_get_bytes(iv, block_size) < 0)
402 return -1;
403
404 data = wpabuf_put(msg, 0);
405 wpabuf_put_buf(msg, plain);
406 if (aes_128_cbc_encrypt(wps->keywrapkey, iv, data, wpabuf_len(plain)))
407 return -1;
408
409 return 0;
410 }
411
412
413 #ifdef CONFIG_WPS_OOB
wps_build_oob_dev_pw(struct wpabuf * msg,u16 dev_pw_id,const struct wpabuf * pubkey,const u8 * dev_pw,size_t dev_pw_len)414 int wps_build_oob_dev_pw(struct wpabuf *msg, u16 dev_pw_id,
415 const struct wpabuf *pubkey, const u8 *dev_pw,
416 size_t dev_pw_len)
417 {
418 size_t hash_len;
419 const u8 *addr[1];
420 u8 pubkey_hash[WPS_HASH_LEN];
421
422 wpa_printf(MSG_DEBUG, "WPS: * OOB Device Password (dev_pw_id=%u)",
423 dev_pw_id);
424 addr[0] = wpabuf_head(pubkey);
425 hash_len = wpabuf_len(pubkey);
426 if (sha256_vector(1, addr, &hash_len, pubkey_hash) < 0)
427 return -1;
428 #ifdef CONFIG_WPS_TESTING
429 if (wps_corrupt_pkhash) {
430 wpa_hexdump(MSG_DEBUG, "WPS: Real Public Key Hash",
431 pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN);
432 wpa_printf(MSG_INFO, "WPS: Testing - corrupt public key hash");
433 pubkey_hash[WPS_OOB_PUBKEY_HASH_LEN - 2]++;
434 }
435 #endif /* CONFIG_WPS_TESTING */
436
437 wpabuf_put_be16(msg, ATTR_OOB_DEVICE_PASSWORD);
438 wpabuf_put_be16(msg, WPS_OOB_PUBKEY_HASH_LEN + 2 + dev_pw_len);
439 wpa_hexdump(MSG_DEBUG, "WPS: Public Key Hash",
440 pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN);
441 wpabuf_put_data(msg, pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN);
442 wpabuf_put_be16(msg, dev_pw_id);
443 if (dev_pw) {
444 wpa_hexdump_key(MSG_DEBUG, "WPS: OOB Device Password",
445 dev_pw, dev_pw_len);
446 wpabuf_put_data(msg, dev_pw, dev_pw_len);
447 }
448
449 return 0;
450 }
451 #endif /* CONFIG_WPS_OOB */
452
453
454 /* Encapsulate WPS IE data with one (or more, if needed) IE headers */
wps_ie_encapsulate(struct wpabuf * data)455 struct wpabuf * wps_ie_encapsulate(struct wpabuf *data)
456 {
457 struct wpabuf *ie;
458 const u8 *pos, *end;
459
460 ie = wpabuf_alloc(wpabuf_len(data) + 100);
461 if (ie == NULL) {
462 wpabuf_free(data);
463 return NULL;
464 }
465
466 pos = wpabuf_head(data);
467 end = pos + wpabuf_len(data);
468
469 while (end > pos) {
470 size_t frag_len = end - pos;
471 if (frag_len > 251)
472 frag_len = 251;
473 wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
474 wpabuf_put_u8(ie, 4 + frag_len);
475 wpabuf_put_be32(ie, WPS_DEV_OUI_WFA);
476 wpabuf_put_data(ie, pos, frag_len);
477 pos += frag_len;
478 }
479
480 wpabuf_free(data);
481
482 return ie;
483 }
484
485
wps_build_mac_addr(struct wpabuf * msg,const u8 * addr)486 int wps_build_mac_addr(struct wpabuf *msg, const u8 *addr)
487 {
488 wpa_printf(MSG_DEBUG, "WPS: * MAC Address (" MACSTR ")",
489 MAC2STR(addr));
490 wpabuf_put_be16(msg, ATTR_MAC_ADDR);
491 wpabuf_put_be16(msg, ETH_ALEN);
492 wpabuf_put_data(msg, addr, ETH_ALEN);
493 return 0;
494 }
495
496
wps_build_rf_bands_attr(struct wpabuf * msg,u8 rf_bands)497 int wps_build_rf_bands_attr(struct wpabuf *msg, u8 rf_bands)
498 {
499 wpa_printf(MSG_DEBUG, "WPS: * RF Bands (%x)", rf_bands);
500 wpabuf_put_be16(msg, ATTR_RF_BANDS);
501 wpabuf_put_be16(msg, 1);
502 wpabuf_put_u8(msg, rf_bands);
503 return 0;
504 }
505
506
wps_build_ap_channel(struct wpabuf * msg,u16 ap_channel)507 int wps_build_ap_channel(struct wpabuf *msg, u16 ap_channel)
508 {
509 wpa_printf(MSG_DEBUG, "WPS: * AP Channel (%u)", ap_channel);
510 wpabuf_put_be16(msg, ATTR_AP_CHANNEL);
511 wpabuf_put_be16(msg, 2);
512 wpabuf_put_be16(msg, ap_channel);
513 return 0;
514 }
515