xref: /freebsd/contrib/wpa/src/eap_server/eap_server_pax.c (revision 0d66206fff44f864ea8a4b220c3a53b4caa959a0)
1 /*
2  * hostapd / EAP-PAX (RFC 4746) server
3  * Copyright (c) 2005-2007, 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/random.h"
13 #include "eap_server/eap_i.h"
14 #include "eap_common/eap_pax_common.h"
15 
16 /*
17  * Note: only PAX_STD subprotocol is currently supported
18  *
19  * TODO: Add support with PAX_SEC with the mandatory to implement ciphersuite
20  * (HMAC_SHA1_128, IANA DH Group 14 (2048 bits), RSA-PKCS1-V1_5) and
21  * recommended ciphersuite (HMAC_SHA256_128, IANA DH Group 15 (3072 bits),
22  * RSAES-OAEP).
23  */
24 
25 struct eap_pax_data {
26 	enum { PAX_STD_1, PAX_STD_3, SUCCESS, FAILURE } state;
27 	u8 mac_id;
28 	union {
29 		u8 e[2 * EAP_PAX_RAND_LEN];
30 		struct {
31 			u8 x[EAP_PAX_RAND_LEN]; /* server rand */
32 			u8 y[EAP_PAX_RAND_LEN]; /* client rand */
33 		} r;
34 	} rand;
35 	u8 ak[EAP_PAX_AK_LEN];
36 	u8 mk[EAP_PAX_MK_LEN];
37 	u8 ck[EAP_PAX_CK_LEN];
38 	u8 ick[EAP_PAX_ICK_LEN];
39 	u8 mid[EAP_PAX_MID_LEN];
40 	int keys_set;
41 	char *cid;
42 	size_t cid_len;
43 };
44 
45 
46 static void * eap_pax_init(struct eap_sm *sm)
47 {
48 	struct eap_pax_data *data;
49 
50 	data = os_zalloc(sizeof(*data));
51 	if (data == NULL)
52 		return NULL;
53 	data->state = PAX_STD_1;
54 	/*
55 	 * TODO: make this configurable once EAP_PAX_HMAC_SHA256_128 is
56 	 * supported
57 	 */
58 	data->mac_id = EAP_PAX_MAC_HMAC_SHA1_128;
59 
60 	return data;
61 }
62 
63 
64 static void eap_pax_reset(struct eap_sm *sm, void *priv)
65 {
66 	struct eap_pax_data *data = priv;
67 	os_free(data->cid);
68 	bin_clear_free(data, sizeof(*data));
69 }
70 
71 
72 static struct wpabuf * eap_pax_build_std_1(struct eap_sm *sm,
73 					   struct eap_pax_data *data, u8 id)
74 {
75 	struct wpabuf *req;
76 	struct eap_pax_hdr *pax;
77 	u8 *pos;
78 
79 	wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-1 (sending)");
80 
81 	if (random_get_bytes(data->rand.r.x, EAP_PAX_RAND_LEN)) {
82 		wpa_printf(MSG_ERROR, "EAP-PAX: Failed to get random data");
83 		data->state = FAILURE;
84 		return NULL;
85 	}
86 
87 	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PAX,
88 			    sizeof(*pax) + 2 + EAP_PAX_RAND_LEN +
89 			    EAP_PAX_ICV_LEN, EAP_CODE_REQUEST, id);
90 	if (req == NULL) {
91 		wpa_printf(MSG_ERROR, "EAP-PAX: Failed to allocate memory "
92 			   "request");
93 		data->state = FAILURE;
94 		return NULL;
95 	}
96 
97 	pax = wpabuf_put(req, sizeof(*pax));
98 	pax->op_code = EAP_PAX_OP_STD_1;
99 	pax->flags = 0;
100 	pax->mac_id = data->mac_id;
101 	pax->dh_group_id = EAP_PAX_DH_GROUP_NONE;
102 	pax->public_key_id = EAP_PAX_PUBLIC_KEY_NONE;
103 
104 	wpabuf_put_be16(req, EAP_PAX_RAND_LEN);
105 	wpabuf_put_data(req, data->rand.r.x, EAP_PAX_RAND_LEN);
106 	wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: A = X (server rand)",
107 		    data->rand.r.x, EAP_PAX_RAND_LEN);
108 
109 	pos = wpabuf_put(req, EAP_PAX_MAC_LEN);
110 	if (eap_pax_mac(data->mac_id, (u8 *) "", 0,
111 			wpabuf_mhead(req), wpabuf_len(req) - EAP_PAX_ICV_LEN,
112 			NULL, 0, NULL, 0, pos) < 0) {
113 		wpa_printf(MSG_ERROR, "EAP-PAX: Failed to calculate ICV");
114 		data->state = FAILURE;
115 		wpabuf_free(req);
116 		return NULL;
117 	}
118 	wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN);
119 
120 	return req;
121 }
122 
123 
124 static struct wpabuf * eap_pax_build_std_3(struct eap_sm *sm,
125 					   struct eap_pax_data *data, u8 id)
126 {
127 	struct wpabuf *req;
128 	struct eap_pax_hdr *pax;
129 	u8 *pos;
130 
131 	wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-3 (sending)");
132 
133 	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PAX,
134 			    sizeof(*pax) + 2 + EAP_PAX_MAC_LEN +
135 			    EAP_PAX_ICV_LEN, EAP_CODE_REQUEST, id);
136 	if (req == NULL) {
137 		wpa_printf(MSG_ERROR, "EAP-PAX: Failed to allocate memory "
138 			   "request");
139 		data->state = FAILURE;
140 		return NULL;
141 	}
142 
143 	pax = wpabuf_put(req, sizeof(*pax));
144 	pax->op_code = EAP_PAX_OP_STD_3;
145 	pax->flags = 0;
146 	pax->mac_id = data->mac_id;
147 	pax->dh_group_id = EAP_PAX_DH_GROUP_NONE;
148 	pax->public_key_id = EAP_PAX_PUBLIC_KEY_NONE;
149 
150 	wpabuf_put_be16(req, EAP_PAX_MAC_LEN);
151 	pos = wpabuf_put(req, EAP_PAX_MAC_LEN);
152 	if (eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
153 			data->rand.r.y, EAP_PAX_RAND_LEN,
154 			(u8 *) data->cid, data->cid_len, NULL, 0, pos) < 0) {
155 		wpa_printf(MSG_ERROR, "EAP-PAX: Failed to calculate MAC");
156 		data->state = FAILURE;
157 		wpabuf_free(req);
158 		return NULL;
159 	}
160 	wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(B, CID)",
161 		    pos, EAP_PAX_MAC_LEN);
162 
163 	/* Optional ADE could be added here, if needed */
164 
165 	pos = wpabuf_put(req, EAP_PAX_MAC_LEN);
166 	if (eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
167 			wpabuf_mhead(req), wpabuf_len(req) - EAP_PAX_ICV_LEN,
168 			NULL, 0, NULL, 0, pos) < 0) {
169 		wpa_printf(MSG_ERROR, "EAP-PAX: Failed to calculate ICV");
170 		data->state = FAILURE;
171 		wpabuf_free(req);
172 		return NULL;
173 	}
174 	wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN);
175 
176 	return req;
177 }
178 
179 
180 static struct wpabuf * eap_pax_buildReq(struct eap_sm *sm, void *priv, u8 id)
181 {
182 	struct eap_pax_data *data = priv;
183 
184 	switch (data->state) {
185 	case PAX_STD_1:
186 		return eap_pax_build_std_1(sm, data, id);
187 	case PAX_STD_3:
188 		return eap_pax_build_std_3(sm, data, id);
189 	default:
190 		wpa_printf(MSG_DEBUG, "EAP-PAX: Unknown state %d in buildReq",
191 			   data->state);
192 		break;
193 	}
194 	return NULL;
195 }
196 
197 
198 static bool eap_pax_check(struct eap_sm *sm, void *priv,
199 			  struct wpabuf *respData)
200 {
201 	struct eap_pax_data *data = priv;
202 	struct eap_pax_hdr *resp;
203 	const u8 *pos;
204 	size_t len, mlen;
205 	u8 icvbuf[EAP_PAX_ICV_LEN], *icv;
206 
207 	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, respData, &len);
208 	if (pos == NULL || len < sizeof(*resp) + EAP_PAX_ICV_LEN) {
209 		wpa_printf(MSG_INFO, "EAP-PAX: Invalid frame");
210 		return true;
211 	}
212 
213 	mlen = sizeof(struct eap_hdr) + 1 + len;
214 	resp = (struct eap_pax_hdr *) pos;
215 
216 	wpa_printf(MSG_DEBUG, "EAP-PAX: received frame: op_code 0x%x "
217 		   "flags 0x%x mac_id 0x%x dh_group_id 0x%x "
218 		   "public_key_id 0x%x",
219 		   resp->op_code, resp->flags, resp->mac_id, resp->dh_group_id,
220 		   resp->public_key_id);
221 	wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: received payload",
222 		    (u8 *) (resp + 1), len - sizeof(*resp) - EAP_PAX_ICV_LEN);
223 
224 	if (data->state == PAX_STD_1 &&
225 	    resp->op_code != EAP_PAX_OP_STD_2) {
226 		wpa_printf(MSG_DEBUG, "EAP-PAX: Expected PAX_STD-2 - "
227 			   "ignore op %d", resp->op_code);
228 		return true;
229 	}
230 
231 	if (data->state == PAX_STD_3 &&
232 	    resp->op_code != EAP_PAX_OP_ACK) {
233 		wpa_printf(MSG_DEBUG, "EAP-PAX: Expected PAX-ACK - "
234 			   "ignore op %d", resp->op_code);
235 		return true;
236 	}
237 
238 	if (resp->op_code != EAP_PAX_OP_STD_2 &&
239 	    resp->op_code != EAP_PAX_OP_ACK) {
240 		wpa_printf(MSG_DEBUG, "EAP-PAX: Unknown op_code 0x%x",
241 			   resp->op_code);
242 	}
243 
244 	if (data->mac_id != resp->mac_id) {
245 		wpa_printf(MSG_DEBUG, "EAP-PAX: Expected MAC ID 0x%x, "
246 			   "received 0x%x", data->mac_id, resp->mac_id);
247 		return true;
248 	}
249 
250 	if (resp->dh_group_id != EAP_PAX_DH_GROUP_NONE) {
251 		wpa_printf(MSG_INFO, "EAP-PAX: Expected DH Group ID 0x%x, "
252 			   "received 0x%x", EAP_PAX_DH_GROUP_NONE,
253 			   resp->dh_group_id);
254 		return true;
255 	}
256 
257 	if (resp->public_key_id != EAP_PAX_PUBLIC_KEY_NONE) {
258 		wpa_printf(MSG_INFO, "EAP-PAX: Expected Public Key ID 0x%x, "
259 			   "received 0x%x", EAP_PAX_PUBLIC_KEY_NONE,
260 			   resp->public_key_id);
261 		return true;
262 	}
263 
264 	if (resp->flags & EAP_PAX_FLAGS_MF) {
265 		/* TODO: add support for reassembling fragments */
266 		wpa_printf(MSG_INFO, "EAP-PAX: fragmentation not supported");
267 		return true;
268 	}
269 
270 	if (resp->flags & EAP_PAX_FLAGS_CE) {
271 		wpa_printf(MSG_INFO, "EAP-PAX: Unexpected CE flag");
272 		return true;
273 	}
274 
275 	if (data->keys_set) {
276 		if (len - sizeof(*resp) < EAP_PAX_ICV_LEN) {
277 			wpa_printf(MSG_INFO, "EAP-PAX: No ICV in the packet");
278 			return true;
279 		}
280 		icv = wpabuf_mhead_u8(respData) + mlen - EAP_PAX_ICV_LEN;
281 		wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", icv, EAP_PAX_ICV_LEN);
282 		if (eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
283 				wpabuf_mhead(respData),
284 				wpabuf_len(respData) - EAP_PAX_ICV_LEN,
285 				NULL, 0, NULL, 0, icvbuf) < 0) {
286 			wpa_printf(MSG_INFO,
287 				   "EAP-PAX: Failed to calculate ICV");
288 			return true;
289 		}
290 
291 		if (os_memcmp_const(icvbuf, icv, EAP_PAX_ICV_LEN) != 0) {
292 			wpa_printf(MSG_INFO, "EAP-PAX: Invalid ICV");
293 			wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected ICV",
294 				    icvbuf, EAP_PAX_ICV_LEN);
295 			return true;
296 		}
297 	}
298 
299 	return false;
300 }
301 
302 
303 static void eap_pax_process_std_2(struct eap_sm *sm,
304 				  struct eap_pax_data *data,
305 				  struct wpabuf *respData)
306 {
307 	struct eap_pax_hdr *resp;
308 	u8 mac[EAP_PAX_MAC_LEN], icvbuf[EAP_PAX_ICV_LEN];
309 	const u8 *pos;
310 	size_t len, left, cid_len;
311 	int i;
312 
313 	if (data->state != PAX_STD_1)
314 		return;
315 
316 	wpa_printf(MSG_DEBUG, "EAP-PAX: Received PAX_STD-2");
317 
318 	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, respData, &len);
319 	if (pos == NULL || len < sizeof(*resp) + EAP_PAX_ICV_LEN)
320 		return;
321 
322 	resp = (struct eap_pax_hdr *) pos;
323 	pos = (u8 *) (resp + 1);
324 	left = len - sizeof(*resp);
325 
326 	if (left < 2 + EAP_PAX_RAND_LEN ||
327 	    WPA_GET_BE16(pos) != EAP_PAX_RAND_LEN) {
328 		wpa_printf(MSG_INFO, "EAP-PAX: Too short PAX_STD-2 (B)");
329 		return;
330 	}
331 	pos += 2;
332 	left -= 2;
333 	os_memcpy(data->rand.r.y, pos, EAP_PAX_RAND_LEN);
334 	wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Y (client rand)",
335 		    data->rand.r.y, EAP_PAX_RAND_LEN);
336 	pos += EAP_PAX_RAND_LEN;
337 	left -= EAP_PAX_RAND_LEN;
338 
339 	if (left < 2 || (size_t) 2 + WPA_GET_BE16(pos) > left) {
340 		wpa_printf(MSG_INFO, "EAP-PAX: Too short PAX_STD-2 (CID)");
341 		return;
342 	}
343 	cid_len = WPA_GET_BE16(pos);
344 	if (cid_len > 1500) {
345 		wpa_printf(MSG_INFO, "EAP-PAX: Too long CID");
346 		return;
347 	}
348 	data->cid_len = cid_len;
349 	os_free(data->cid);
350 	data->cid = os_memdup(pos + 2, data->cid_len);
351 	if (data->cid == NULL) {
352 		wpa_printf(MSG_INFO, "EAP-PAX: Failed to allocate memory for "
353 			   "CID");
354 		return;
355 	}
356 	pos += 2 + data->cid_len;
357 	left -= 2 + data->cid_len;
358 	wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-PAX: CID",
359 			  (u8 *) data->cid, data->cid_len);
360 
361 	if (left < 2 + EAP_PAX_MAC_LEN ||
362 	    WPA_GET_BE16(pos) != EAP_PAX_MAC_LEN) {
363 		wpa_printf(MSG_INFO, "EAP-PAX: Too short PAX_STD-2 (MAC_CK)");
364 		return;
365 	}
366 	pos += 2;
367 	left -= 2;
368 	wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(A, B, CID)",
369 		    pos, EAP_PAX_MAC_LEN);
370 
371 	if (eap_user_get(sm, (u8 *) data->cid, data->cid_len, 0) < 0) {
372 		wpa_hexdump_ascii(MSG_DEBUG, "EAP-PAX: unknown CID",
373 				  (u8 *) data->cid, data->cid_len);
374 		data->state = FAILURE;
375 		return;
376 	}
377 
378 	for (i = 0;
379 	     i < EAP_MAX_METHODS &&
380 		     (sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
381 		      sm->user->methods[i].method != EAP_TYPE_NONE);
382 	     i++) {
383 		if (sm->user->methods[i].vendor == EAP_VENDOR_IETF &&
384 		    sm->user->methods[i].method == EAP_TYPE_PAX)
385 			break;
386 	}
387 
388 	if (i >= EAP_MAX_METHODS ||
389 	    sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
390 	    sm->user->methods[i].method != EAP_TYPE_PAX) {
391 		wpa_hexdump_ascii(MSG_DEBUG,
392 				  "EAP-PAX: EAP-PAX not enabled for CID",
393 				  (u8 *) data->cid, data->cid_len);
394 		data->state = FAILURE;
395 		return;
396 	}
397 
398 	if (sm->user->password == NULL ||
399 	    sm->user->password_len != EAP_PAX_AK_LEN) {
400 		wpa_hexdump_ascii(MSG_DEBUG, "EAP-PAX: invalid password in "
401 				  "user database for CID",
402 				  (u8 *) data->cid, data->cid_len);
403 		data->state = FAILURE;
404 		return;
405 	}
406 	os_memcpy(data->ak, sm->user->password, EAP_PAX_AK_LEN);
407 
408 	if (eap_pax_initial_key_derivation(data->mac_id, data->ak,
409 					   data->rand.e, data->mk, data->ck,
410 					   data->ick, data->mid) < 0) {
411 		wpa_printf(MSG_INFO, "EAP-PAX: Failed to complete initial "
412 			   "key derivation");
413 		data->state = FAILURE;
414 		return;
415 	}
416 	data->keys_set = 1;
417 
418 	if (eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
419 			data->rand.r.x, EAP_PAX_RAND_LEN,
420 			data->rand.r.y, EAP_PAX_RAND_LEN,
421 			(u8 *) data->cid, data->cid_len, mac) < 0) {
422 		wpa_printf(MSG_INFO, "EAP-PAX: Failed to calculate MAC_CK");
423 		data->state = FAILURE;
424 		return;
425 	}
426 
427 	if (os_memcmp_const(mac, pos, EAP_PAX_MAC_LEN) != 0) {
428 		wpa_printf(MSG_INFO, "EAP-PAX: Invalid MAC_CK(A, B, CID) in "
429 			   "PAX_STD-2");
430 		wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected MAC_CK(A, B, CID)",
431 			    mac, EAP_PAX_MAC_LEN);
432 		data->state = FAILURE;
433 		return;
434 	}
435 
436 	pos += EAP_PAX_MAC_LEN;
437 	left -= EAP_PAX_MAC_LEN;
438 
439 	if (left < EAP_PAX_ICV_LEN) {
440 		wpa_printf(MSG_INFO, "EAP-PAX: Too short ICV (%lu) in "
441 			   "PAX_STD-2", (unsigned long) left);
442 		return;
443 	}
444 	wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN);
445 	if (eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
446 			wpabuf_head(respData),
447 			wpabuf_len(respData) - EAP_PAX_ICV_LEN, NULL, 0,
448 			NULL, 0, icvbuf) < 0) {
449 		wpa_printf(MSG_INFO, "EAP-PAX: Failed to calculate ICV");
450 		return;
451 	}
452 
453 	if (os_memcmp_const(icvbuf, pos, EAP_PAX_ICV_LEN) != 0) {
454 		wpa_printf(MSG_INFO, "EAP-PAX: Invalid ICV in PAX_STD-2");
455 		wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected ICV",
456 			    icvbuf, EAP_PAX_ICV_LEN);
457 		return;
458 	}
459 	pos += EAP_PAX_ICV_LEN;
460 	left -= EAP_PAX_ICV_LEN;
461 
462 	if (left > 0) {
463 		wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ignored extra payload",
464 			    pos, left);
465 	}
466 
467 	data->state = PAX_STD_3;
468 }
469 
470 
471 static void eap_pax_process_ack(struct eap_sm *sm,
472 				struct eap_pax_data *data,
473 				struct wpabuf *respData)
474 {
475 	if (data->state != PAX_STD_3)
476 		return;
477 
478 	wpa_printf(MSG_DEBUG, "EAP-PAX: Received PAX-ACK - authentication "
479 		   "completed successfully");
480 	data->state = SUCCESS;
481 }
482 
483 
484 static void eap_pax_process(struct eap_sm *sm, void *priv,
485 			    struct wpabuf *respData)
486 {
487 	struct eap_pax_data *data = priv;
488 	struct eap_pax_hdr *resp;
489 	const u8 *pos;
490 	size_t len;
491 
492 	if (sm->user == NULL || sm->user->password == NULL) {
493 		wpa_printf(MSG_INFO, "EAP-PAX: Plaintext password not "
494 			   "configured");
495 		data->state = FAILURE;
496 		return;
497 	}
498 
499 	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, respData, &len);
500 	if (pos == NULL || len < sizeof(*resp))
501 		return;
502 
503 	resp = (struct eap_pax_hdr *) pos;
504 
505 	switch (resp->op_code) {
506 	case EAP_PAX_OP_STD_2:
507 		eap_pax_process_std_2(sm, data, respData);
508 		break;
509 	case EAP_PAX_OP_ACK:
510 		eap_pax_process_ack(sm, data, respData);
511 		break;
512 	}
513 }
514 
515 
516 static bool eap_pax_isDone(struct eap_sm *sm, void *priv)
517 {
518 	struct eap_pax_data *data = priv;
519 	return data->state == SUCCESS || data->state == FAILURE;
520 }
521 
522 
523 static u8 * eap_pax_getKey(struct eap_sm *sm, void *priv, size_t *len)
524 {
525 	struct eap_pax_data *data = priv;
526 	u8 *key;
527 
528 	if (data->state != SUCCESS)
529 		return NULL;
530 
531 	key = os_malloc(EAP_MSK_LEN);
532 	if (key == NULL)
533 		return NULL;
534 
535 	*len = EAP_MSK_LEN;
536 	eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
537 		    "Master Session Key", data->rand.e, 2 * EAP_PAX_RAND_LEN,
538 		    EAP_MSK_LEN, key);
539 
540 	return key;
541 }
542 
543 
544 static u8 * eap_pax_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
545 {
546 	struct eap_pax_data *data = priv;
547 	u8 *key;
548 
549 	if (data->state != SUCCESS)
550 		return NULL;
551 
552 	key = os_malloc(EAP_EMSK_LEN);
553 	if (key == NULL)
554 		return NULL;
555 
556 	*len = EAP_EMSK_LEN;
557 	eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
558 		    "Extended Master Session Key",
559 		    data->rand.e, 2 * EAP_PAX_RAND_LEN,
560 		    EAP_EMSK_LEN, key);
561 
562 	return key;
563 }
564 
565 
566 static bool eap_pax_isSuccess(struct eap_sm *sm, void *priv)
567 {
568 	struct eap_pax_data *data = priv;
569 	return data->state == SUCCESS;
570 }
571 
572 
573 static u8 * eap_pax_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
574 {
575 	struct eap_pax_data *data = priv;
576 	u8 *sid;
577 
578 	if (data->state != SUCCESS)
579 		return NULL;
580 
581 	sid = os_malloc(1 + EAP_PAX_MID_LEN);
582 	if (sid == NULL)
583 		return NULL;
584 
585 	*len = 1 + EAP_PAX_MID_LEN;
586 	sid[0] = EAP_TYPE_PAX;
587 	os_memcpy(sid + 1, data->mid, EAP_PAX_MID_LEN);
588 
589 	return sid;
590 }
591 
592 
593 int eap_server_pax_register(void)
594 {
595 	struct eap_method *eap;
596 
597 	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
598 				      EAP_VENDOR_IETF, EAP_TYPE_PAX, "PAX");
599 	if (eap == NULL)
600 		return -1;
601 
602 	eap->init = eap_pax_init;
603 	eap->reset = eap_pax_reset;
604 	eap->buildReq = eap_pax_buildReq;
605 	eap->check = eap_pax_check;
606 	eap->process = eap_pax_process;
607 	eap->isDone = eap_pax_isDone;
608 	eap->getKey = eap_pax_getKey;
609 	eap->isSuccess = eap_pax_isSuccess;
610 	eap->get_emsk = eap_pax_get_emsk;
611 	eap->getSessionId = eap_pax_get_session_id;
612 
613 	return eap_server_method_register(eap);
614 }
615