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
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;
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
wps_build_req_type(struct wpabuf * msg,enum wps_request_type type)96 int 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
wps_build_resp_type(struct wpabuf * msg,enum wps_response_type type)106 int 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
wps_build_config_methods(struct wpabuf * msg,u16 methods)116 int 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
wps_build_uuid_e(struct wpabuf * msg,const u8 * uuid)126 int 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
wps_build_dev_password_id(struct wpabuf * msg,u16 id)138 int 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
wps_build_config_error(struct wpabuf * msg,u16 err)148 int 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
wps_build_authenticator(struct wps_data * wps,struct wpabuf * msg)158 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 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
wps_build_version(struct wpabuf * msg)188 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 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
wps_build_wfa_ext(struct wpabuf * msg,int req_to_enroll,const u8 * auth_macs,size_t auth_macs_count)205 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 if (WPS_VERSION == 0x10)
212 return 0;
213 #endif /* CONFIG_WPS_TESTING */
214
215 if (wpabuf_tailroom(msg) <
216 7 + 3 + (req_to_enroll ? 3 : 0) +
217 (auth_macs ? 2 + auth_macs_count * ETH_ALEN : 0))
218 return -1;
219 wpabuf_put_be16(msg, ATTR_VENDOR_EXT);
220 len = wpabuf_put(msg, 2); /* to be filled */
221 wpabuf_put_be24(msg, WPS_VENDOR_ID_WFA);
222
223 wpa_printf(MSG_DEBUG, "WPS: * Version2 (0x%x)", WPS_VERSION);
224 wpabuf_put_u8(msg, WFA_ELEM_VERSION2);
225 wpabuf_put_u8(msg, 1);
226 wpabuf_put_u8(msg, WPS_VERSION);
227
228 if (req_to_enroll) {
229 wpa_printf(MSG_DEBUG, "WPS: * Request to Enroll (1)");
230 wpabuf_put_u8(msg, WFA_ELEM_REQUEST_TO_ENROLL);
231 wpabuf_put_u8(msg, 1);
232 wpabuf_put_u8(msg, 1);
233 }
234
235 if (auth_macs && auth_macs_count) {
236 size_t i;
237 wpa_printf(MSG_DEBUG, "WPS: * AuthorizedMACs (count=%d)",
238 (int) auth_macs_count);
239 wpabuf_put_u8(msg, WFA_ELEM_AUTHORIZEDMACS);
240 wpabuf_put_u8(msg, auth_macs_count * ETH_ALEN);
241 wpabuf_put_data(msg, auth_macs, auth_macs_count * ETH_ALEN);
242 for (i = 0; i < auth_macs_count; i++)
243 wpa_printf(MSG_DEBUG, "WPS: AuthorizedMAC: " MACSTR,
244 MAC2STR(&auth_macs[i * ETH_ALEN]));
245 }
246
247 WPA_PUT_BE16(len, (u8 *) wpabuf_put(msg, 0) - len - 2);
248
249 #ifdef CONFIG_WPS_TESTING
250 if (WPS_VERSION > 0x20) {
251 if (wpabuf_tailroom(msg) < 5)
252 return -1;
253 wpa_printf(MSG_DEBUG, "WPS: * Extensibility Testing - extra "
254 "attribute");
255 wpabuf_put_be16(msg, ATTR_EXTENSIBILITY_TEST);
256 wpabuf_put_be16(msg, 1);
257 wpabuf_put_u8(msg, 42);
258 }
259 #endif /* CONFIG_WPS_TESTING */
260 return 0;
261 }
262
263
wps_build_msg_type(struct wpabuf * msg,enum wps_msg_type msg_type)264 int wps_build_msg_type(struct wpabuf *msg, enum wps_msg_type msg_type)
265 {
266 wpa_printf(MSG_DEBUG, "WPS: * Message Type (%d)", msg_type);
267 wpabuf_put_be16(msg, ATTR_MSG_TYPE);
268 wpabuf_put_be16(msg, 1);
269 wpabuf_put_u8(msg, msg_type);
270 return 0;
271 }
272
273
wps_build_enrollee_nonce(struct wps_data * wps,struct wpabuf * msg)274 int wps_build_enrollee_nonce(struct wps_data *wps, struct wpabuf *msg)
275 {
276 wpa_printf(MSG_DEBUG, "WPS: * Enrollee Nonce");
277 wpabuf_put_be16(msg, ATTR_ENROLLEE_NONCE);
278 wpabuf_put_be16(msg, WPS_NONCE_LEN);
279 wpabuf_put_data(msg, wps->nonce_e, WPS_NONCE_LEN);
280 return 0;
281 }
282
283
wps_build_registrar_nonce(struct wps_data * wps,struct wpabuf * msg)284 int wps_build_registrar_nonce(struct wps_data *wps, struct wpabuf *msg)
285 {
286 wpa_printf(MSG_DEBUG, "WPS: * Registrar Nonce");
287 wpabuf_put_be16(msg, ATTR_REGISTRAR_NONCE);
288 wpabuf_put_be16(msg, WPS_NONCE_LEN);
289 wpabuf_put_data(msg, wps->nonce_r, WPS_NONCE_LEN);
290 return 0;
291 }
292
293
wps_build_auth_type_flags(struct wps_data * wps,struct wpabuf * msg)294 int wps_build_auth_type_flags(struct wps_data *wps, struct wpabuf *msg)
295 {
296 u16 auth_types = WPS_AUTH_TYPES;
297 /* WPA/WPA2-Enterprise enrollment not supported through WPS */
298 auth_types &= ~WPS_AUTH_WPA;
299 auth_types &= ~WPS_AUTH_WPA2;
300 auth_types &= ~WPS_AUTH_SHARED;
301 wpa_printf(MSG_DEBUG, "WPS: * Authentication Type Flags");
302 wpabuf_put_be16(msg, ATTR_AUTH_TYPE_FLAGS);
303 wpabuf_put_be16(msg, 2);
304 wpabuf_put_be16(msg, auth_types);
305 return 0;
306 }
307
308
wps_build_encr_type_flags(struct wps_data * wps,struct wpabuf * msg)309 int wps_build_encr_type_flags(struct wps_data *wps, struct wpabuf *msg)
310 {
311 u16 encr_types = WPS_ENCR_TYPES;
312 encr_types &= ~WPS_ENCR_WEP;
313 wpa_printf(MSG_DEBUG, "WPS: * Encryption Type Flags");
314 wpabuf_put_be16(msg, ATTR_ENCR_TYPE_FLAGS);
315 wpabuf_put_be16(msg, 2);
316 wpabuf_put_be16(msg, encr_types);
317 return 0;
318 }
319
320
wps_build_conn_type_flags(struct wps_data * wps,struct wpabuf * msg)321 int wps_build_conn_type_flags(struct wps_data *wps, struct wpabuf *msg)
322 {
323 wpa_printf(MSG_DEBUG, "WPS: * Connection Type Flags");
324 wpabuf_put_be16(msg, ATTR_CONN_TYPE_FLAGS);
325 wpabuf_put_be16(msg, 1);
326 wpabuf_put_u8(msg, WPS_CONN_ESS);
327 return 0;
328 }
329
330
wps_build_assoc_state(struct wps_data * wps,struct wpabuf * msg)331 int wps_build_assoc_state(struct wps_data *wps, struct wpabuf *msg)
332 {
333 wpa_printf(MSG_DEBUG, "WPS: * Association State");
334 wpabuf_put_be16(msg, ATTR_ASSOC_STATE);
335 wpabuf_put_be16(msg, 2);
336 wpabuf_put_be16(msg, WPS_ASSOC_NOT_ASSOC);
337 return 0;
338 }
339
340
wps_build_key_wrap_auth(struct wps_data * wps,struct wpabuf * msg)341 int wps_build_key_wrap_auth(struct wps_data *wps, struct wpabuf *msg)
342 {
343 u8 hash[SHA256_MAC_LEN];
344
345 wpa_printf(MSG_DEBUG, "WPS: * Key Wrap Authenticator");
346 hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, wpabuf_head(msg),
347 wpabuf_len(msg), hash);
348
349 wpabuf_put_be16(msg, ATTR_KEY_WRAP_AUTH);
350 wpabuf_put_be16(msg, WPS_KWA_LEN);
351 wpabuf_put_data(msg, hash, WPS_KWA_LEN);
352 return 0;
353 }
354
355
wps_build_encr_settings(struct wps_data * wps,struct wpabuf * msg,struct wpabuf * plain)356 int wps_build_encr_settings(struct wps_data *wps, struct wpabuf *msg,
357 struct wpabuf *plain)
358 {
359 size_t pad_len;
360 const size_t block_size = 16;
361 u8 *iv, *data;
362
363 wpa_printf(MSG_DEBUG, "WPS: * Encrypted Settings");
364
365 /* PKCS#5 v2.0 pad */
366 pad_len = block_size - wpabuf_len(plain) % block_size;
367 os_memset(wpabuf_put(plain, pad_len), pad_len, pad_len);
368
369 wpabuf_put_be16(msg, ATTR_ENCR_SETTINGS);
370 wpabuf_put_be16(msg, block_size + wpabuf_len(plain));
371
372 iv = wpabuf_put(msg, block_size);
373 if (random_get_bytes(iv, block_size) < 0)
374 return -1;
375
376 data = wpabuf_put(msg, 0);
377 wpabuf_put_buf(msg, plain);
378 if (aes_128_cbc_encrypt(wps->keywrapkey, iv, data, wpabuf_len(plain)))
379 return -1;
380
381 return 0;
382 }
383
384
385 #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)386 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 wpa_printf(MSG_DEBUG, "WPS: * OOB Device Password (dev_pw_id=%u)",
395 dev_pw_id);
396 addr[0] = wpabuf_head(pubkey);
397 hash_len = wpabuf_len(pubkey);
398 sha256_vector(1, addr, &hash_len, pubkey_hash);
399 #ifdef CONFIG_WPS_TESTING
400 if (wps_corrupt_pkhash) {
401 wpa_hexdump(MSG_DEBUG, "WPS: Real Public Key Hash",
402 pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN);
403 wpa_printf(MSG_INFO, "WPS: Testing - corrupt public key hash");
404 pubkey_hash[WPS_OOB_PUBKEY_HASH_LEN - 2]++;
405 }
406 #endif /* CONFIG_WPS_TESTING */
407
408 wpabuf_put_be16(msg, ATTR_OOB_DEVICE_PASSWORD);
409 wpabuf_put_be16(msg, WPS_OOB_PUBKEY_HASH_LEN + 2 + dev_pw_len);
410 wpa_hexdump(MSG_DEBUG, "WPS: Public Key Hash",
411 pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN);
412 wpabuf_put_data(msg, pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN);
413 wpabuf_put_be16(msg, dev_pw_id);
414 if (dev_pw) {
415 wpa_hexdump_key(MSG_DEBUG, "WPS: OOB Device Password",
416 dev_pw, dev_pw_len);
417 wpabuf_put_data(msg, dev_pw, dev_pw_len);
418 }
419
420 return 0;
421 }
422 #endif /* CONFIG_WPS_OOB */
423
424
425 /* Encapsulate WPS IE data with one (or more, if needed) IE headers */
wps_ie_encapsulate(struct wpabuf * data)426 struct wpabuf * wps_ie_encapsulate(struct wpabuf *data)
427 {
428 struct wpabuf *ie;
429 const u8 *pos, *end;
430
431 ie = wpabuf_alloc(wpabuf_len(data) + 100);
432 if (ie == NULL) {
433 wpabuf_free(data);
434 return NULL;
435 }
436
437 pos = wpabuf_head(data);
438 end = pos + wpabuf_len(data);
439
440 while (end > pos) {
441 size_t frag_len = end - pos;
442 if (frag_len > 251)
443 frag_len = 251;
444 wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
445 wpabuf_put_u8(ie, 4 + frag_len);
446 wpabuf_put_be32(ie, WPS_DEV_OUI_WFA);
447 wpabuf_put_data(ie, pos, frag_len);
448 pos += frag_len;
449 }
450
451 wpabuf_free(data);
452
453 return ie;
454 }
455
456
wps_build_mac_addr(struct wpabuf * msg,const u8 * addr)457 int wps_build_mac_addr(struct wpabuf *msg, const u8 *addr)
458 {
459 wpa_printf(MSG_DEBUG, "WPS: * MAC Address (" MACSTR ")",
460 MAC2STR(addr));
461 wpabuf_put_be16(msg, ATTR_MAC_ADDR);
462 wpabuf_put_be16(msg, ETH_ALEN);
463 wpabuf_put_data(msg, addr, ETH_ALEN);
464 return 0;
465 }
466
467
wps_build_rf_bands_attr(struct wpabuf * msg,u8 rf_bands)468 int wps_build_rf_bands_attr(struct wpabuf *msg, u8 rf_bands)
469 {
470 wpa_printf(MSG_DEBUG, "WPS: * RF Bands (%x)", rf_bands);
471 wpabuf_put_be16(msg, ATTR_RF_BANDS);
472 wpabuf_put_be16(msg, 1);
473 wpabuf_put_u8(msg, rf_bands);
474 return 0;
475 }
476
477
wps_build_ap_channel(struct wpabuf * msg,u16 ap_channel)478 int wps_build_ap_channel(struct wpabuf *msg, u16 ap_channel)
479 {
480 wpa_printf(MSG_DEBUG, "WPS: * AP Channel (%u)", ap_channel);
481 wpabuf_put_be16(msg, ATTR_AP_CHANNEL);
482 wpabuf_put_be16(msg, 2);
483 wpabuf_put_be16(msg, ap_channel);
484 return 0;
485 }
486