Line data Source code
1 : /*
2 : * EAP-IKEv2 peer (RFC 5106)
3 : * Copyright (c) 2007-2014, 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 "eap_i.h"
13 : #include "eap_common/eap_ikev2_common.h"
14 : #include "ikev2.h"
15 :
16 :
17 : struct eap_ikev2_data {
18 : struct ikev2_responder_data ikev2;
19 : enum { WAIT_START, PROC_MSG, WAIT_FRAG_ACK, DONE, FAIL } state;
20 : struct wpabuf *in_buf;
21 : struct wpabuf *out_buf;
22 : size_t out_used;
23 : size_t fragment_size;
24 : int keys_ready;
25 : u8 keymat[EAP_MSK_LEN + EAP_EMSK_LEN];
26 : int keymat_ok;
27 : };
28 :
29 :
30 158 : static const char * eap_ikev2_state_txt(int state)
31 : {
32 158 : switch (state) {
33 : case WAIT_START:
34 50 : return "WAIT_START";
35 : case PROC_MSG:
36 48 : return "PROC_MSG";
37 : case WAIT_FRAG_ACK:
38 16 : return "WAIT_FRAG_ACK";
39 : case DONE:
40 6 : return "DONE";
41 : case FAIL:
42 38 : return "FAIL";
43 : default:
44 0 : return "?";
45 : }
46 : }
47 :
48 :
49 79 : static void eap_ikev2_state(struct eap_ikev2_data *data, int state)
50 : {
51 158 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: %s -> %s",
52 79 : eap_ikev2_state_txt(data->state),
53 : eap_ikev2_state_txt(state));
54 79 : data->state = state;
55 79 : }
56 :
57 :
58 60 : static void * eap_ikev2_init(struct eap_sm *sm)
59 : {
60 : struct eap_ikev2_data *data;
61 : const u8 *identity, *password;
62 : size_t identity_len, password_len;
63 : int fragment_size;
64 :
65 60 : identity = eap_get_config_identity(sm, &identity_len);
66 60 : if (identity == NULL) {
67 0 : wpa_printf(MSG_INFO, "EAP-IKEV2: No identity available");
68 0 : return NULL;
69 : }
70 :
71 60 : data = os_zalloc(sizeof(*data));
72 60 : if (data == NULL)
73 0 : return NULL;
74 60 : data->state = WAIT_START;
75 60 : fragment_size = eap_get_config_fragment_size(sm);
76 60 : if (fragment_size <= 0)
77 0 : data->fragment_size = IKEV2_FRAGMENT_SIZE;
78 : else
79 60 : data->fragment_size = fragment_size;
80 60 : data->ikev2.state = SA_INIT;
81 60 : data->ikev2.peer_auth = PEER_AUTH_SECRET;
82 60 : data->ikev2.key_pad = (u8 *) os_strdup("Key Pad for EAP-IKEv2");
83 60 : if (data->ikev2.key_pad == NULL)
84 0 : goto failed;
85 60 : data->ikev2.key_pad_len = 21;
86 60 : data->ikev2.IDr = os_malloc(identity_len);
87 60 : if (data->ikev2.IDr == NULL)
88 0 : goto failed;
89 60 : os_memcpy(data->ikev2.IDr, identity, identity_len);
90 60 : data->ikev2.IDr_len = identity_len;
91 :
92 60 : password = eap_get_config_password(sm, &password_len);
93 60 : if (password) {
94 60 : data->ikev2.shared_secret = os_malloc(password_len);
95 60 : if (data->ikev2.shared_secret == NULL)
96 0 : goto failed;
97 60 : os_memcpy(data->ikev2.shared_secret, password, password_len);
98 60 : data->ikev2.shared_secret_len = password_len;
99 : }
100 :
101 60 : return data;
102 :
103 : failed:
104 0 : ikev2_responder_deinit(&data->ikev2);
105 0 : os_free(data);
106 0 : return NULL;
107 : }
108 :
109 :
110 60 : static void eap_ikev2_deinit(struct eap_sm *sm, void *priv)
111 : {
112 60 : struct eap_ikev2_data *data = priv;
113 60 : wpabuf_free(data->in_buf);
114 60 : wpabuf_free(data->out_buf);
115 60 : ikev2_responder_deinit(&data->ikev2);
116 60 : bin_clear_free(data, sizeof(*data));
117 60 : }
118 :
119 :
120 6 : static int eap_ikev2_peer_keymat(struct eap_ikev2_data *data)
121 : {
122 18 : if (eap_ikev2_derive_keymat(
123 : data->ikev2.proposal.prf, &data->ikev2.keys,
124 6 : data->ikev2.i_nonce, data->ikev2.i_nonce_len,
125 6 : data->ikev2.r_nonce, data->ikev2.r_nonce_len,
126 6 : data->keymat) < 0) {
127 0 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to "
128 : "derive key material");
129 0 : return -1;
130 : }
131 6 : data->keymat_ok = 1;
132 6 : return 0;
133 : }
134 :
135 :
136 27 : static struct wpabuf * eap_ikev2_build_msg(struct eap_ikev2_data *data,
137 : struct eap_method_ret *ret, u8 id)
138 : {
139 : struct wpabuf *resp;
140 : u8 flags;
141 27 : size_t send_len, plen, icv_len = 0;
142 :
143 27 : ret->ignore = FALSE;
144 27 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Generating Response");
145 27 : ret->allowNotifications = TRUE;
146 :
147 27 : flags = 0;
148 27 : send_len = wpabuf_len(data->out_buf) - data->out_used;
149 27 : if (1 + send_len > data->fragment_size) {
150 8 : send_len = data->fragment_size - 1;
151 8 : flags |= IKEV2_FLAGS_MORE_FRAGMENTS;
152 8 : if (data->out_used == 0) {
153 2 : flags |= IKEV2_FLAGS_LENGTH_INCLUDED;
154 2 : send_len -= 4;
155 : }
156 : }
157 :
158 27 : plen = 1 + send_len;
159 27 : if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
160 2 : plen += 4;
161 27 : if (data->keys_ready) {
162 : const struct ikev2_integ_alg *integ;
163 9 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Add Integrity Checksum "
164 : "Data");
165 9 : flags |= IKEV2_FLAGS_ICV_INCLUDED;
166 9 : integ = ikev2_get_integ(data->ikev2.proposal.integ);
167 9 : if (integ == NULL) {
168 0 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unknown INTEG "
169 : "transform / cannot generate ICV");
170 0 : return NULL;
171 : }
172 9 : icv_len = integ->hash_len;
173 :
174 9 : plen += icv_len;
175 : }
176 27 : resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, plen,
177 : EAP_CODE_RESPONSE, id);
178 27 : if (resp == NULL)
179 0 : return NULL;
180 :
181 27 : wpabuf_put_u8(resp, flags); /* Flags */
182 27 : if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
183 2 : wpabuf_put_be32(resp, wpabuf_len(data->out_buf));
184 :
185 27 : wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
186 : send_len);
187 27 : data->out_used += send_len;
188 :
189 27 : if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
190 9 : const u8 *msg = wpabuf_head(resp);
191 9 : size_t len = wpabuf_len(resp);
192 18 : ikev2_integ_hash(data->ikev2.proposal.integ,
193 9 : data->ikev2.keys.SK_ar,
194 : data->ikev2.keys.SK_integ_len,
195 9 : msg, len, wpabuf_put(resp, icv_len));
196 : }
197 :
198 27 : ret->methodState = METHOD_MAY_CONT;
199 27 : ret->decision = DECISION_FAIL;
200 :
201 27 : if (data->out_used == wpabuf_len(data->out_buf)) {
202 19 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
203 : "(message sent completely)",
204 : (unsigned long) send_len);
205 19 : wpabuf_free(data->out_buf);
206 19 : data->out_buf = NULL;
207 19 : data->out_used = 0;
208 19 : switch (data->ikev2.state) {
209 : case SA_AUTH:
210 : /* SA_INIT was sent out, so message have to be
211 : * integrity protected from now on. */
212 11 : data->keys_ready = 1;
213 11 : break;
214 : case IKEV2_DONE:
215 6 : ret->methodState = METHOD_DONE;
216 6 : if (data->state == FAIL)
217 0 : break;
218 6 : ret->decision = DECISION_COND_SUCC;
219 6 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication "
220 : "completed successfully");
221 6 : if (eap_ikev2_peer_keymat(data))
222 0 : break;
223 6 : eap_ikev2_state(data, DONE);
224 6 : break;
225 : case IKEV2_FAILED:
226 1 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication "
227 : "failed");
228 1 : ret->methodState = METHOD_DONE;
229 1 : ret->decision = DECISION_FAIL;
230 1 : break;
231 : default:
232 1 : break;
233 : }
234 : } else {
235 8 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
236 : "(%lu more to send)", (unsigned long) send_len,
237 8 : (unsigned long) wpabuf_len(data->out_buf) -
238 8 : data->out_used);
239 8 : eap_ikev2_state(data, WAIT_FRAG_ACK);
240 : }
241 :
242 27 : return resp;
243 : }
244 :
245 :
246 91 : static int eap_ikev2_process_icv(struct eap_ikev2_data *data,
247 : const struct wpabuf *reqData,
248 : u8 flags, const u8 *pos, const u8 **end,
249 : int frag_ack)
250 : {
251 91 : if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
252 14 : int icv_len = eap_ikev2_validate_icv(
253 : data->ikev2.proposal.integ, &data->ikev2.keys, 1,
254 : reqData, pos, *end);
255 14 : if (icv_len < 0)
256 3 : return -1;
257 : /* Hide Integrity Checksum Data from further processing */
258 11 : *end -= icv_len;
259 77 : } else if (data->keys_ready && !frag_ack) {
260 1 : wpa_printf(MSG_INFO, "EAP-IKEV2: The message should have "
261 : "included integrity checksum");
262 1 : return -1;
263 : }
264 :
265 87 : return 0;
266 : }
267 :
268 :
269 13 : static int eap_ikev2_process_cont(struct eap_ikev2_data *data,
270 : const u8 *buf, size_t len)
271 : {
272 : /* Process continuation of a pending message */
273 13 : if (len > wpabuf_tailroom(data->in_buf)) {
274 1 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment overflow");
275 1 : eap_ikev2_state(data, FAIL);
276 1 : return -1;
277 : }
278 :
279 12 : wpabuf_put_data(data->in_buf, buf, len);
280 12 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes, waiting "
281 : "for %lu bytes more", (unsigned long) len,
282 12 : (unsigned long) wpabuf_tailroom(data->in_buf));
283 :
284 12 : return 0;
285 : }
286 :
287 :
288 16 : static struct wpabuf * eap_ikev2_process_fragment(struct eap_ikev2_data *data,
289 : struct eap_method_ret *ret,
290 : u8 id, u8 flags,
291 : u32 message_length,
292 : const u8 *buf, size_t len)
293 : {
294 : /* Process a fragment that is not the last one of the message */
295 16 : if (data->in_buf == NULL && !(flags & IKEV2_FLAGS_LENGTH_INCLUDED)) {
296 1 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: No Message Length field in "
297 : "a fragmented packet");
298 1 : ret->ignore = TRUE;
299 1 : return NULL;
300 : }
301 :
302 15 : if (data->in_buf == NULL) {
303 : /* First fragment of the message */
304 7 : if (message_length > 50000) {
305 : /* Limit maximum memory allocation */
306 2 : wpa_printf(MSG_DEBUG,
307 : "EAP-IKEV2: Ignore too long message");
308 2 : ret->ignore = TRUE;
309 2 : return NULL;
310 : }
311 5 : data->in_buf = wpabuf_alloc(message_length);
312 5 : if (data->in_buf == NULL) {
313 0 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: No memory for "
314 : "message");
315 0 : ret->ignore = TRUE;
316 0 : return NULL;
317 : }
318 5 : wpabuf_put_data(data->in_buf, buf, len);
319 5 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes in first "
320 : "fragment, waiting for %lu bytes more",
321 : (unsigned long) len,
322 5 : (unsigned long) wpabuf_tailroom(data->in_buf));
323 : }
324 :
325 13 : ret->ignore = FALSE;
326 13 : return eap_ikev2_build_frag_ack(id, EAP_CODE_RESPONSE);
327 : }
328 :
329 :
330 91 : static struct wpabuf * eap_ikev2_process(struct eap_sm *sm, void *priv,
331 : struct eap_method_ret *ret,
332 : const struct wpabuf *reqData)
333 : {
334 91 : struct eap_ikev2_data *data = priv;
335 : const u8 *start, *pos, *end;
336 : size_t len;
337 : u8 flags, id;
338 91 : u32 message_length = 0;
339 : struct wpabuf tmpbuf;
340 :
341 91 : pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, reqData, &len);
342 91 : if (pos == NULL) {
343 0 : ret->ignore = TRUE;
344 0 : return NULL;
345 : }
346 :
347 91 : id = eap_get_id(reqData);
348 :
349 91 : start = pos;
350 91 : end = start + len;
351 :
352 91 : if (len == 0)
353 9 : flags = 0; /* fragment ack */
354 : else
355 82 : flags = *pos++;
356 :
357 99 : if (eap_ikev2_process_icv(data, reqData, flags, pos, &end,
358 99 : data->state == WAIT_FRAG_ACK && len == 0) < 0)
359 : {
360 4 : ret->ignore = TRUE;
361 4 : return NULL;
362 : }
363 :
364 87 : if (flags & IKEV2_FLAGS_LENGTH_INCLUDED) {
365 11 : if (end - pos < 4) {
366 1 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Message underflow");
367 1 : ret->ignore = TRUE;
368 1 : return NULL;
369 : }
370 10 : message_length = WPA_GET_BE32(pos);
371 10 : pos += 4;
372 :
373 10 : if (message_length < (u32) (end - pos)) {
374 1 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Invalid Message "
375 : "Length (%d; %ld remaining in this msg)",
376 : message_length, (long) (end - pos));
377 1 : ret->ignore = TRUE;
378 1 : return NULL;
379 : }
380 : }
381 :
382 85 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received packet: Flags 0x%x "
383 : "Message Length %u", flags, message_length);
384 :
385 85 : if (data->state == WAIT_FRAG_ACK) {
386 8 : if (len != 0) {
387 0 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unexpected payload "
388 : "in WAIT_FRAG_ACK state");
389 0 : ret->ignore = TRUE;
390 0 : return NULL;
391 : }
392 8 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment acknowledged");
393 8 : eap_ikev2_state(data, PROC_MSG);
394 8 : return eap_ikev2_build_msg(data, ret, id);
395 : }
396 :
397 77 : if (data->in_buf && eap_ikev2_process_cont(data, pos, end - pos) < 0) {
398 1 : ret->ignore = TRUE;
399 1 : return NULL;
400 : }
401 :
402 76 : if (flags & IKEV2_FLAGS_MORE_FRAGMENTS) {
403 16 : return eap_ikev2_process_fragment(data, ret, id, flags,
404 : message_length, pos,
405 16 : end - pos);
406 : }
407 :
408 60 : if (data->in_buf == NULL) {
409 : /* Wrap unfragmented messages as wpabuf without extra copy */
410 56 : wpabuf_set(&tmpbuf, pos, end - pos);
411 56 : data->in_buf = &tmpbuf;
412 : }
413 :
414 60 : if (ikev2_responder_process(&data->ikev2, data->in_buf) < 0) {
415 37 : if (data->in_buf == &tmpbuf)
416 37 : data->in_buf = NULL;
417 37 : eap_ikev2_state(data, FAIL);
418 37 : return NULL;
419 : }
420 :
421 23 : if (data->in_buf != &tmpbuf)
422 4 : wpabuf_free(data->in_buf);
423 23 : data->in_buf = NULL;
424 :
425 23 : if (data->out_buf == NULL) {
426 23 : data->out_buf = ikev2_responder_build(&data->ikev2);
427 23 : if (data->out_buf == NULL) {
428 4 : wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to generate "
429 : "IKEv2 message");
430 4 : return NULL;
431 : }
432 19 : data->out_used = 0;
433 : }
434 :
435 19 : eap_ikev2_state(data, PROC_MSG);
436 19 : return eap_ikev2_build_msg(data, ret, id);
437 : }
438 :
439 :
440 49 : static Boolean eap_ikev2_isKeyAvailable(struct eap_sm *sm, void *priv)
441 : {
442 49 : struct eap_ikev2_data *data = priv;
443 49 : return data->state == DONE && data->keymat_ok;
444 : }
445 :
446 :
447 6 : static u8 * eap_ikev2_getKey(struct eap_sm *sm, void *priv, size_t *len)
448 : {
449 6 : struct eap_ikev2_data *data = priv;
450 : u8 *key;
451 :
452 6 : if (data->state != DONE || !data->keymat_ok)
453 0 : return NULL;
454 :
455 6 : key = os_malloc(EAP_MSK_LEN);
456 6 : if (key) {
457 6 : os_memcpy(key, data->keymat, EAP_MSK_LEN);
458 6 : *len = EAP_MSK_LEN;
459 : }
460 :
461 6 : return key;
462 : }
463 :
464 :
465 1 : static u8 * eap_ikev2_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
466 : {
467 1 : struct eap_ikev2_data *data = priv;
468 : u8 *key;
469 :
470 1 : if (data->state != DONE || !data->keymat_ok)
471 0 : return NULL;
472 :
473 1 : key = os_malloc(EAP_EMSK_LEN);
474 1 : if (key) {
475 1 : os_memcpy(key, data->keymat + EAP_MSK_LEN, EAP_EMSK_LEN);
476 1 : *len = EAP_EMSK_LEN;
477 : }
478 :
479 1 : return key;
480 : }
481 :
482 :
483 6 : static u8 * eap_ikev2_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
484 : {
485 6 : struct eap_ikev2_data *data = priv;
486 : u8 *sid;
487 : size_t sid_len;
488 : size_t offset;
489 :
490 6 : if (data->state != DONE || !data->keymat_ok)
491 0 : return NULL;
492 :
493 6 : sid_len = 1 + data->ikev2.i_nonce_len + data->ikev2.r_nonce_len;
494 6 : sid = os_malloc(sid_len);
495 6 : if (sid) {
496 6 : offset = 0;
497 6 : sid[offset] = EAP_TYPE_IKEV2;
498 6 : offset++;
499 6 : os_memcpy(sid + offset, data->ikev2.i_nonce,
500 : data->ikev2.i_nonce_len);
501 6 : offset += data->ikev2.i_nonce_len;
502 6 : os_memcpy(sid + offset, data->ikev2.r_nonce,
503 : data->ikev2.r_nonce_len);
504 6 : *len = sid_len;
505 6 : wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Derived Session-Id",
506 : sid, sid_len);
507 : }
508 :
509 6 : return sid;
510 : }
511 :
512 :
513 49 : int eap_peer_ikev2_register(void)
514 : {
515 : struct eap_method *eap;
516 : int ret;
517 :
518 49 : eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
519 : EAP_VENDOR_IETF, EAP_TYPE_IKEV2,
520 : "IKEV2");
521 49 : if (eap == NULL)
522 0 : return -1;
523 :
524 49 : eap->init = eap_ikev2_init;
525 49 : eap->deinit = eap_ikev2_deinit;
526 49 : eap->process = eap_ikev2_process;
527 49 : eap->isKeyAvailable = eap_ikev2_isKeyAvailable;
528 49 : eap->getKey = eap_ikev2_getKey;
529 49 : eap->get_emsk = eap_ikev2_get_emsk;
530 49 : eap->getSessionId = eap_ikev2_get_session_id;
531 :
532 49 : ret = eap_peer_method_register(eap);
533 49 : if (ret)
534 0 : eap_peer_method_free(eap);
535 49 : return ret;
536 : }
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