Line data Source code
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 :
21 557 : int wps_build_public_key(struct wps_data *wps, struct wpabuf *msg)
22 : {
23 : struct wpabuf *pubkey;
24 :
25 557 : wpa_printf(MSG_DEBUG, "WPS: * Public Key");
26 557 : wpabuf_free(wps->dh_privkey);
27 557 : wps->dh_privkey = NULL;
28 674 : if (wps->dev_pw_id != DEV_PW_DEFAULT && wps->wps->dh_privkey &&
29 117 : wps->wps->dh_ctx) {
30 42 : wpa_printf(MSG_DEBUG, "WPS: Using pre-configured DH keys");
31 42 : if (wps->wps->dh_pubkey == NULL) {
32 0 : wpa_printf(MSG_DEBUG,
33 : "WPS: wps->wps->dh_pubkey == NULL");
34 0 : return -1;
35 : }
36 42 : wps->dh_privkey = wpabuf_dup(wps->wps->dh_privkey);
37 42 : wps->dh_ctx = wps->wps->dh_ctx;
38 42 : wps->wps->dh_ctx = NULL;
39 42 : pubkey = wpabuf_dup(wps->wps->dh_pubkey);
40 : #ifdef CONFIG_WPS_NFC
41 1023 : } else if ((wps->dev_pw_id >= 0x10 ||
42 524 : wps->dev_pw_id == DEV_PW_NFC_CONNECTION_HANDOVER) &&
43 20 : (wps->wps->ap ||
44 7 : (wps->wps->ap_nfc_dh_pubkey &&
45 3 : wps->wps->ap_nfc_dev_pw_id ==
46 3 : DEV_PW_NFC_CONNECTION_HANDOVER &&
47 17 : wps->dev_pw_id == DEV_PW_NFC_CONNECTION_HANDOVER)) &&
48 17 : (wps->dev_pw_id == wps->wps->ap_nfc_dev_pw_id ||
49 3 : wps->wps->ap_nfc_dh_pubkey)) {
50 12 : wpa_printf(MSG_DEBUG, "WPS: Using NFC password token DH keys");
51 12 : if (wps->wps->ap_nfc_dh_privkey == NULL) {
52 0 : wpa_printf(MSG_DEBUG,
53 : "WPS: wps->wps->ap_nfc_dh_privkey == NULL");
54 0 : return -1;
55 : }
56 12 : if (wps->wps->ap_nfc_dh_pubkey == NULL) {
57 0 : wpa_printf(MSG_DEBUG,
58 : "WPS: wps->wps->ap_nfc_dh_pubkey == NULL");
59 0 : return -1;
60 : }
61 12 : wps->dh_privkey = wpabuf_dup(wps->wps->ap_nfc_dh_privkey);
62 12 : pubkey = wpabuf_dup(wps->wps->ap_nfc_dh_pubkey);
63 12 : wps->dh_ctx = dh5_init_fixed(wps->dh_privkey, pubkey);
64 : #endif /* CONFIG_WPS_NFC */
65 : } else {
66 503 : wpa_printf(MSG_DEBUG, "WPS: Generate new DH keys");
67 503 : dh5_free(wps->dh_ctx);
68 503 : wps->dh_ctx = dh5_init(&wps->dh_privkey, &pubkey);
69 503 : pubkey = wpabuf_zeropad(pubkey, 192);
70 : }
71 557 : if (wps->dh_ctx == NULL || wps->dh_privkey == NULL || pubkey == NULL) {
72 0 : wpa_printf(MSG_DEBUG, "WPS: Failed to initialize "
73 : "Diffie-Hellman handshake");
74 0 : wpabuf_free(pubkey);
75 0 : return -1;
76 : }
77 557 : wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH Private Key", wps->dh_privkey);
78 557 : wpa_hexdump_buf(MSG_DEBUG, "WPS: DH own Public Key", pubkey);
79 :
80 557 : wpabuf_put_be16(msg, ATTR_PUBLIC_KEY);
81 557 : wpabuf_put_be16(msg, wpabuf_len(pubkey));
82 557 : wpabuf_put_buf(msg, pubkey);
83 :
84 557 : if (wps->registrar) {
85 265 : wpabuf_free(wps->dh_pubkey_r);
86 265 : wps->dh_pubkey_r = pubkey;
87 : } else {
88 292 : wpabuf_free(wps->dh_pubkey_e);
89 292 : wps->dh_pubkey_e = pubkey;
90 : }
91 :
92 557 : return 0;
93 : }
94 :
95 :
96 3006 : int wps_build_req_type(struct wpabuf *msg, enum wps_request_type type)
97 : {
98 3006 : wpa_printf(MSG_DEBUG, "WPS: * Request Type");
99 3006 : wpabuf_put_be16(msg, ATTR_REQUEST_TYPE);
100 3006 : wpabuf_put_be16(msg, 1);
101 3006 : wpabuf_put_u8(msg, type);
102 3006 : return 0;
103 : }
104 :
105 :
106 2965 : int wps_build_resp_type(struct wpabuf *msg, enum wps_response_type type)
107 : {
108 2965 : wpa_printf(MSG_DEBUG, "WPS: * Response Type (%d)", type);
109 2965 : wpabuf_put_be16(msg, ATTR_RESPONSE_TYPE);
110 2965 : wpabuf_put_be16(msg, 1);
111 2965 : wpabuf_put_u8(msg, type);
112 2965 : return 0;
113 : }
114 :
115 :
116 3307 : int wps_build_config_methods(struct wpabuf *msg, u16 methods)
117 : {
118 3307 : wpa_printf(MSG_DEBUG, "WPS: * Config Methods (%x)", methods);
119 3307 : wpabuf_put_be16(msg, ATTR_CONFIG_METHODS);
120 3307 : wpabuf_put_be16(msg, 2);
121 3307 : wpabuf_put_be16(msg, methods);
122 3307 : return 0;
123 : }
124 :
125 :
126 6453 : int wps_build_uuid_e(struct wpabuf *msg, const u8 *uuid)
127 : {
128 6453 : if (wpabuf_tailroom(msg) < 4 + WPS_UUID_LEN)
129 0 : return -1;
130 6453 : wpa_printf(MSG_DEBUG, "WPS: * UUID-E");
131 6453 : wpabuf_put_be16(msg, ATTR_UUID_E);
132 6453 : wpabuf_put_be16(msg, WPS_UUID_LEN);
133 6453 : wpabuf_put_data(msg, uuid, WPS_UUID_LEN);
134 6453 : return 0;
135 : }
136 :
137 :
138 3283 : int wps_build_dev_password_id(struct wpabuf *msg, u16 id)
139 : {
140 3283 : wpa_printf(MSG_DEBUG, "WPS: * Device Password ID (%d)", id);
141 3283 : wpabuf_put_be16(msg, ATTR_DEV_PASSWORD_ID);
142 3283 : wpabuf_put_be16(msg, 2);
143 3283 : wpabuf_put_be16(msg, id);
144 3283 : return 0;
145 : }
146 :
147 :
148 3369 : int wps_build_config_error(struct wpabuf *msg, u16 err)
149 : {
150 3369 : wpa_printf(MSG_DEBUG, "WPS: * Configuration Error (%d)", err);
151 3369 : wpabuf_put_be16(msg, ATTR_CONFIG_ERROR);
152 3369 : wpabuf_put_be16(msg, 2);
153 3369 : wpabuf_put_be16(msg, err);
154 3369 : return 0;
155 : }
156 :
157 :
158 1655 : int 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 1655 : if (wps->last_msg == NULL) {
165 0 : wpa_printf(MSG_DEBUG, "WPS: Last message not available for "
166 : "building authenticator");
167 0 : 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 1655 : addr[0] = wpabuf_head(wps->last_msg);
174 1655 : len[0] = wpabuf_len(wps->last_msg);
175 1655 : addr[1] = wpabuf_head(msg);
176 1655 : len[1] = wpabuf_len(msg);
177 1655 : hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 2, addr, len, hash);
178 :
179 1655 : wpa_printf(MSG_DEBUG, "WPS: * Authenticator");
180 1655 : wpabuf_put_be16(msg, ATTR_AUTHENTICATOR);
181 1655 : wpabuf_put_be16(msg, WPS_AUTHENTICATOR_LEN);
182 1655 : wpabuf_put_data(msg, hash, WPS_AUTHENTICATOR_LEN);
183 :
184 1655 : return 0;
185 : }
186 :
187 :
188 12034 : int 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 12034 : if (wpabuf_tailroom(msg) < 5)
196 0 : return -1;
197 12034 : wpa_printf(MSG_DEBUG, "WPS: * Version (hardcoded 0x10)");
198 12034 : wpabuf_put_be16(msg, ATTR_VERSION);
199 12034 : wpabuf_put_be16(msg, 1);
200 12034 : wpabuf_put_u8(msg, 0x10);
201 12034 : return 0;
202 : }
203 :
204 :
205 12108 : int wps_build_wfa_ext(struct wpabuf *msg, int req_to_enroll,
206 : const u8 *auth_macs, size_t auth_macs_count)
207 : {
208 : u8 *len;
209 :
210 : #ifdef CONFIG_WPS_TESTING
211 12108 : if (WPS_VERSION == 0x10)
212 41 : return 0;
213 : #endif /* CONFIG_WPS_TESTING */
214 :
215 24134 : if (wpabuf_tailroom(msg) <
216 24134 : 7 + 3 + (req_to_enroll ? 3 : 0) +
217 12067 : (auth_macs ? 2 + auth_macs_count * ETH_ALEN : 0))
218 0 : return -1;
219 12067 : wpabuf_put_be16(msg, ATTR_VENDOR_EXT);
220 12067 : len = wpabuf_put(msg, 2); /* to be filled */
221 12067 : wpabuf_put_be24(msg, WPS_VENDOR_ID_WFA);
222 :
223 12067 : wpa_printf(MSG_DEBUG, "WPS: * Version2 (0x%x)", WPS_VERSION);
224 12067 : wpabuf_put_u8(msg, WFA_ELEM_VERSION2);
225 12067 : wpabuf_put_u8(msg, 1);
226 12067 : wpabuf_put_u8(msg, WPS_VERSION);
227 :
228 12067 : if (req_to_enroll) {
229 1113 : wpa_printf(MSG_DEBUG, "WPS: * Request to Enroll (1)");
230 1113 : wpabuf_put_u8(msg, WFA_ELEM_REQUEST_TO_ENROLL);
231 1113 : wpabuf_put_u8(msg, 1);
232 1113 : wpabuf_put_u8(msg, 1);
233 : }
234 :
235 12067 : if (auth_macs && auth_macs_count) {
236 : size_t i;
237 555 : wpa_printf(MSG_DEBUG, "WPS: * AuthorizedMACs (count=%d)",
238 : (int) auth_macs_count);
239 555 : wpabuf_put_u8(msg, WFA_ELEM_AUTHORIZEDMACS);
240 555 : wpabuf_put_u8(msg, auth_macs_count * ETH_ALEN);
241 555 : wpabuf_put_data(msg, auth_macs, auth_macs_count * ETH_ALEN);
242 1110 : for (i = 0; i < auth_macs_count; i++)
243 3330 : wpa_printf(MSG_DEBUG, "WPS: AuthorizedMAC: " MACSTR,
244 3330 : MAC2STR(&auth_macs[i * ETH_ALEN]));
245 : }
246 :
247 12067 : WPA_PUT_BE16(len, (u8 *) wpabuf_put(msg, 0) - len - 2);
248 :
249 : #ifdef CONFIG_WPS_TESTING
250 12067 : if (WPS_VERSION > 0x20) {
251 21 : if (wpabuf_tailroom(msg) < 5)
252 0 : return -1;
253 21 : wpa_printf(MSG_DEBUG, "WPS: * Extensibility Testing - extra "
254 : "attribute");
255 21 : wpabuf_put_be16(msg, ATTR_EXTENSIBILITY_TEST);
256 21 : wpabuf_put_be16(msg, 1);
257 21 : wpabuf_put_u8(msg, 42);
258 : }
259 : #endif /* CONFIG_WPS_TESTING */
260 12067 : return 0;
261 : }
262 :
263 :
264 2283 : int wps_build_msg_type(struct wpabuf *msg, enum wps_msg_type msg_type)
265 : {
266 2283 : wpa_printf(MSG_DEBUG, "WPS: * Message Type (%d)", msg_type);
267 2283 : wpabuf_put_be16(msg, ATTR_MSG_TYPE);
268 2283 : wpabuf_put_be16(msg, 1);
269 2283 : wpabuf_put_u8(msg, msg_type);
270 2283 : return 0;
271 : }
272 :
273 :
274 1577 : int wps_build_enrollee_nonce(struct wps_data *wps, struct wpabuf *msg)
275 : {
276 1577 : wpa_printf(MSG_DEBUG, "WPS: * Enrollee Nonce");
277 1577 : wpabuf_put_be16(msg, ATTR_ENROLLEE_NONCE);
278 1577 : wpabuf_put_be16(msg, WPS_NONCE_LEN);
279 1577 : wpabuf_put_data(msg, wps->nonce_e, WPS_NONCE_LEN);
280 1577 : return 0;
281 : }
282 :
283 :
284 1305 : int wps_build_registrar_nonce(struct wps_data *wps, struct wpabuf *msg)
285 : {
286 1305 : wpa_printf(MSG_DEBUG, "WPS: * Registrar Nonce");
287 1305 : wpabuf_put_be16(msg, ATTR_REGISTRAR_NONCE);
288 1305 : wpabuf_put_be16(msg, WPS_NONCE_LEN);
289 1305 : wpabuf_put_data(msg, wps->nonce_r, WPS_NONCE_LEN);
290 1305 : return 0;
291 : }
292 :
293 :
294 581 : int wps_build_auth_type_flags(struct wps_data *wps, struct wpabuf *msg)
295 : {
296 581 : u16 auth_types = WPS_AUTH_TYPES;
297 : /* WPA/WPA2-Enterprise enrollment not supported through WPS */
298 581 : auth_types &= ~WPS_AUTH_WPA;
299 581 : auth_types &= ~WPS_AUTH_WPA2;
300 581 : auth_types &= ~WPS_AUTH_SHARED;
301 581 : wpa_printf(MSG_DEBUG, "WPS: * Authentication Type Flags");
302 581 : wpabuf_put_be16(msg, ATTR_AUTH_TYPE_FLAGS);
303 581 : wpabuf_put_be16(msg, 2);
304 581 : wpabuf_put_be16(msg, auth_types);
305 581 : return 0;
306 : }
307 :
308 :
309 581 : int wps_build_encr_type_flags(struct wps_data *wps, struct wpabuf *msg)
310 : {
311 581 : u16 encr_types = WPS_ENCR_TYPES;
312 581 : encr_types &= ~WPS_ENCR_WEP;
313 581 : wpa_printf(MSG_DEBUG, "WPS: * Encryption Type Flags");
314 581 : wpabuf_put_be16(msg, ATTR_ENCR_TYPE_FLAGS);
315 581 : wpabuf_put_be16(msg, 2);
316 581 : wpabuf_put_be16(msg, encr_types);
317 581 : return 0;
318 : }
319 :
320 :
321 581 : int wps_build_conn_type_flags(struct wps_data *wps, struct wpabuf *msg)
322 : {
323 581 : wpa_printf(MSG_DEBUG, "WPS: * Connection Type Flags");
324 581 : wpabuf_put_be16(msg, ATTR_CONN_TYPE_FLAGS);
325 581 : wpabuf_put_be16(msg, 1);
326 581 : wpabuf_put_u8(msg, WPS_CONN_ESS);
327 581 : return 0;
328 : }
329 :
330 :
331 3307 : int wps_build_assoc_state(struct wps_data *wps, struct wpabuf *msg)
332 : {
333 3307 : wpa_printf(MSG_DEBUG, "WPS: * Association State");
334 3307 : wpabuf_put_be16(msg, ATTR_ASSOC_STATE);
335 3307 : wpabuf_put_be16(msg, 2);
336 3307 : wpabuf_put_be16(msg, WPS_ASSOC_NOT_ASSOC);
337 3307 : return 0;
338 : }
339 :
340 :
341 1162 : int wps_build_key_wrap_auth(struct wps_data *wps, struct wpabuf *msg)
342 : {
343 : u8 hash[SHA256_MAC_LEN];
344 :
345 1162 : wpa_printf(MSG_DEBUG, "WPS: * Key Wrap Authenticator");
346 1162 : hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, wpabuf_head(msg),
347 : wpabuf_len(msg), hash);
348 :
349 1162 : wpabuf_put_be16(msg, ATTR_KEY_WRAP_AUTH);
350 1162 : wpabuf_put_be16(msg, WPS_KWA_LEN);
351 1162 : wpabuf_put_data(msg, hash, WPS_KWA_LEN);
352 1162 : return 0;
353 : }
354 :
355 :
356 1162 : int wps_build_encr_settings(struct wps_data *wps, struct wpabuf *msg,
357 : struct wpabuf *plain)
358 : {
359 : size_t pad_len;
360 1162 : const size_t block_size = 16;
361 : u8 *iv, *data;
362 :
363 1162 : wpa_printf(MSG_DEBUG, "WPS: * Encrypted Settings");
364 :
365 : /* PKCS#5 v2.0 pad */
366 1162 : pad_len = block_size - wpabuf_len(plain) % block_size;
367 1162 : os_memset(wpabuf_put(plain, pad_len), pad_len, pad_len);
368 :
369 1162 : wpabuf_put_be16(msg, ATTR_ENCR_SETTINGS);
370 1162 : wpabuf_put_be16(msg, block_size + wpabuf_len(plain));
371 :
372 1162 : iv = wpabuf_put(msg, block_size);
373 1162 : if (random_get_bytes(iv, block_size) < 0)
374 0 : return -1;
375 :
376 1162 : data = wpabuf_put(msg, 0);
377 1162 : wpabuf_put_buf(msg, plain);
378 1162 : if (aes_128_cbc_encrypt(wps->keywrapkey, iv, data, wpabuf_len(plain)))
379 0 : return -1;
380 :
381 1162 : return 0;
382 : }
383 :
384 :
385 : #ifdef CONFIG_WPS_OOB
386 69 : int wps_build_oob_dev_pw(struct wpabuf *msg, u16 dev_pw_id,
387 : const struct wpabuf *pubkey, const u8 *dev_pw,
388 : size_t dev_pw_len)
389 : {
390 : size_t hash_len;
391 : const u8 *addr[1];
392 : u8 pubkey_hash[WPS_HASH_LEN];
393 :
394 69 : wpa_printf(MSG_DEBUG, "WPS: * OOB Device Password (dev_pw_id=%u)",
395 : dev_pw_id);
396 69 : addr[0] = wpabuf_head(pubkey);
397 69 : hash_len = wpabuf_len(pubkey);
398 69 : sha256_vector(1, addr, &hash_len, pubkey_hash);
399 : #ifdef CONFIG_WPS_TESTING
400 69 : if (wps_corrupt_pkhash) {
401 4 : wpa_hexdump(MSG_DEBUG, "WPS: Real Public Key Hash",
402 : pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN);
403 4 : wpa_printf(MSG_INFO, "WPS: Testing - corrupt public key hash");
404 4 : pubkey_hash[WPS_OOB_PUBKEY_HASH_LEN - 2]++;
405 : }
406 : #endif /* CONFIG_WPS_TESTING */
407 :
408 69 : wpabuf_put_be16(msg, ATTR_OOB_DEVICE_PASSWORD);
409 69 : wpabuf_put_be16(msg, WPS_OOB_PUBKEY_HASH_LEN + 2 + dev_pw_len);
410 69 : wpa_hexdump(MSG_DEBUG, "WPS: Public Key Hash",
411 : pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN);
412 69 : wpabuf_put_data(msg, pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN);
413 69 : wpabuf_put_be16(msg, dev_pw_id);
414 69 : if (dev_pw) {
415 26 : wpa_hexdump_key(MSG_DEBUG, "WPS: OOB Device Password",
416 : dev_pw, dev_pw_len);
417 26 : wpabuf_put_data(msg, dev_pw, dev_pw_len);
418 : }
419 :
420 69 : return 0;
421 : }
422 : #endif /* CONFIG_WPS_OOB */
423 :
424 :
425 : /* Encapsulate WPS IE data with one (or more, if needed) IE headers */
426 4700 : struct wpabuf * wps_ie_encapsulate(struct wpabuf *data)
427 : {
428 : struct wpabuf *ie;
429 : const u8 *pos, *end;
430 :
431 4700 : ie = wpabuf_alloc(wpabuf_len(data) + 100);
432 4700 : if (ie == NULL) {
433 0 : wpabuf_free(data);
434 0 : return NULL;
435 : }
436 :
437 4700 : pos = wpabuf_head(data);
438 4700 : end = pos + wpabuf_len(data);
439 :
440 14103 : while (end > pos) {
441 4703 : size_t frag_len = end - pos;
442 4703 : if (frag_len > 251)
443 3 : frag_len = 251;
444 4703 : wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
445 4703 : wpabuf_put_u8(ie, 4 + frag_len);
446 4703 : wpabuf_put_be32(ie, WPS_DEV_OUI_WFA);
447 4703 : wpabuf_put_data(ie, pos, frag_len);
448 4703 : pos += frag_len;
449 : }
450 :
451 4700 : wpabuf_free(data);
452 :
453 4700 : return ie;
454 : }
455 :
456 :
457 555 : int wps_build_mac_addr(struct wpabuf *msg, const u8 *addr)
458 : {
459 3330 : wpa_printf(MSG_DEBUG, "WPS: * MAC Address (" MACSTR ")",
460 3330 : MAC2STR(addr));
461 555 : wpabuf_put_be16(msg, ATTR_MAC_ADDR);
462 555 : wpabuf_put_be16(msg, ETH_ALEN);
463 555 : wpabuf_put_data(msg, addr, ETH_ALEN);
464 555 : return 0;
465 : }
466 :
467 :
468 3370 : int wps_build_rf_bands_attr(struct wpabuf *msg, u8 rf_bands)
469 : {
470 3370 : wpa_printf(MSG_DEBUG, "WPS: * RF Bands (%x)", rf_bands);
471 3370 : wpabuf_put_be16(msg, ATTR_RF_BANDS);
472 3370 : wpabuf_put_be16(msg, 1);
473 3370 : wpabuf_put_u8(msg, rf_bands);
474 3370 : return 0;
475 : }
476 :
477 :
478 12 : int wps_build_ap_channel(struct wpabuf *msg, u16 ap_channel)
479 : {
480 12 : wpa_printf(MSG_DEBUG, "WPS: * AP Channel (%u)", ap_channel);
481 12 : wpabuf_put_be16(msg, ATTR_AP_CHANNEL);
482 12 : wpabuf_put_be16(msg, 2);
483 12 : wpabuf_put_be16(msg, ap_channel);
484 12 : return 0;
485 : }
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