2 * EAP peer method: EAP-SAKE (RFC 4763)
3 * Copyright (c) 2006-2008, Jouni Malinen <j@w1.fi>
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
12 #include "crypto/random.h"
13 #include "eap_peer/eap_i.h"
14 #include "eap_common/eap_sake_common.h"
16 struct eap_sake_data {
17 enum { IDENTITY, CHALLENGE, CONFIRM, SUCCESS, FAILURE } state;
18 u8 root_secret_a[EAP_SAKE_ROOT_SECRET_LEN];
19 u8 root_secret_b[EAP_SAKE_ROOT_SECRET_LEN];
20 u8 rand_s[EAP_SAKE_RAND_LEN];
21 u8 rand_p[EAP_SAKE_RAND_LEN];
23 u8 auth[EAP_SAKE_TEK_AUTH_LEN];
24 u8 cipher[EAP_SAKE_TEK_CIPHER_LEN];
27 u8 emsk[EAP_EMSK_LEN];
37 static const char * eap_sake_state_txt(int state)
56 static void eap_sake_state(struct eap_sake_data *data, int state)
58 wpa_printf(MSG_DEBUG, "EAP-SAKE: %s -> %s",
59 eap_sake_state_txt(data->state),
60 eap_sake_state_txt(state));
65 static void eap_sake_deinit(struct eap_sm *sm, void *priv);
68 static void * eap_sake_init(struct eap_sm *sm)
70 struct eap_sake_data *data;
71 const u8 *identity, *password;
72 size_t identity_len, password_len;
74 password = eap_get_config_password(sm, &password_len);
75 if (!password || password_len != 2 * EAP_SAKE_ROOT_SECRET_LEN) {
76 wpa_printf(MSG_INFO, "EAP-SAKE: No key of correct length "
81 data = os_zalloc(sizeof(*data));
84 data->state = IDENTITY;
86 identity = eap_get_config_identity(sm, &identity_len);
88 data->peerid = os_memdup(identity, identity_len);
89 if (data->peerid == NULL) {
90 eap_sake_deinit(sm, data);
93 data->peerid_len = identity_len;
96 os_memcpy(data->root_secret_a, password, EAP_SAKE_ROOT_SECRET_LEN);
97 os_memcpy(data->root_secret_b,
98 password + EAP_SAKE_ROOT_SECRET_LEN,
99 EAP_SAKE_ROOT_SECRET_LEN);
105 static void eap_sake_deinit(struct eap_sm *sm, void *priv)
107 struct eap_sake_data *data = priv;
108 os_free(data->serverid);
109 os_free(data->peerid);
110 bin_clear_free(data, sizeof(*data));
114 static struct wpabuf * eap_sake_build_msg(struct eap_sake_data *data,
115 int id, size_t length, u8 subtype)
117 struct eap_sake_hdr *sake;
121 plen = length + sizeof(struct eap_sake_hdr);
123 msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_SAKE, plen,
124 EAP_CODE_RESPONSE, id);
126 wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to allocate memory "
131 sake = wpabuf_put(msg, sizeof(*sake));
132 sake->version = EAP_SAKE_VERSION;
133 sake->session_id = data->session_id;
134 sake->subtype = subtype;
140 static struct wpabuf * eap_sake_process_identity(struct eap_sm *sm,
141 struct eap_sake_data *data,
142 struct eap_method_ret *ret,
147 struct eap_sake_parse_attr attr;
150 if (data->state != IDENTITY) {
155 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Request/Identity");
157 if (eap_sake_parse_attributes(payload, payload_len, &attr))
160 if (!attr.perm_id_req && !attr.any_id_req) {
161 wpa_printf(MSG_INFO, "EAP-SAKE: No AT_PERM_ID_REQ or "
162 "AT_ANY_ID_REQ in Request/Identity");
166 wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Identity");
168 resp = eap_sake_build_msg(data, id, 2 + data->peerid_len,
169 EAP_SAKE_SUBTYPE_IDENTITY);
173 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_PEERID");
174 eap_sake_add_attr(resp, EAP_SAKE_AT_PEERID,
175 data->peerid, data->peerid_len);
177 eap_sake_state(data, CHALLENGE);
183 static struct wpabuf * eap_sake_process_challenge(struct eap_sm *sm,
184 struct eap_sake_data *data,
185 struct eap_method_ret *ret,
190 struct eap_sake_parse_attr attr;
195 if (data->state != IDENTITY && data->state != CHALLENGE) {
196 wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Challenge received "
197 "in unexpected state (%d)", data->state);
201 if (data->state == IDENTITY)
202 eap_sake_state(data, CHALLENGE);
204 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Request/Challenge");
206 if (eap_sake_parse_attributes(payload, payload_len, &attr))
210 wpa_printf(MSG_INFO, "EAP-SAKE: Request/Challenge did not "
211 "include AT_RAND_S");
215 os_memcpy(data->rand_s, attr.rand_s, EAP_SAKE_RAND_LEN);
216 wpa_hexdump(MSG_MSGDUMP, "EAP-SAKE: RAND_S (server rand)",
217 data->rand_s, EAP_SAKE_RAND_LEN);
219 if (random_get_bytes(data->rand_p, EAP_SAKE_RAND_LEN)) {
220 wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to get random data");
223 wpa_hexdump(MSG_MSGDUMP, "EAP-SAKE: RAND_P (peer rand)",
224 data->rand_p, EAP_SAKE_RAND_LEN);
226 os_free(data->serverid);
227 data->serverid = NULL;
228 data->serverid_len = 0;
230 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-SAKE: SERVERID",
231 attr.serverid, attr.serverid_len);
232 data->serverid = os_memdup(attr.serverid, attr.serverid_len);
233 if (data->serverid == NULL)
235 data->serverid_len = attr.serverid_len;
238 eap_sake_derive_keys(data->root_secret_a, data->root_secret_b,
239 data->rand_s, data->rand_p,
240 (u8 *) &data->tek, data->msk, data->emsk);
242 wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Challenge");
244 rlen = 2 + EAP_SAKE_RAND_LEN + 2 + EAP_SAKE_MIC_LEN;
246 rlen += 2 + data->peerid_len;
247 resp = eap_sake_build_msg(data, id, rlen, EAP_SAKE_SUBTYPE_CHALLENGE);
251 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_RAND_P");
252 eap_sake_add_attr(resp, EAP_SAKE_AT_RAND_P,
253 data->rand_p, EAP_SAKE_RAND_LEN);
256 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_PEERID");
257 eap_sake_add_attr(resp, EAP_SAKE_AT_PEERID,
258 data->peerid, data->peerid_len);
261 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_MIC_P");
262 wpabuf_put_u8(resp, EAP_SAKE_AT_MIC_P);
263 wpabuf_put_u8(resp, 2 + EAP_SAKE_MIC_LEN);
264 rpos = wpabuf_put(resp, EAP_SAKE_MIC_LEN);
265 if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
266 data->serverid, data->serverid_len,
267 data->peerid, data->peerid_len, 1,
268 wpabuf_head(resp), wpabuf_len(resp), rpos,
270 wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
275 eap_sake_state(data, CONFIRM);
281 static struct wpabuf * eap_sake_process_confirm(struct eap_sm *sm,
282 struct eap_sake_data *data,
283 struct eap_method_ret *ret,
285 const struct wpabuf *reqData,
289 struct eap_sake_parse_attr attr;
290 u8 mic_s[EAP_SAKE_MIC_LEN];
294 if (data->state != CONFIRM) {
299 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Request/Confirm");
301 if (eap_sake_parse_attributes(payload, payload_len, &attr))
305 wpa_printf(MSG_INFO, "EAP-SAKE: Request/Confirm did not "
310 if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
311 data->serverid, data->serverid_len,
312 data->peerid, data->peerid_len, 0,
313 wpabuf_head(reqData), wpabuf_len(reqData),
314 attr.mic_s, mic_s)) {
315 wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
316 eap_sake_state(data, FAILURE);
317 ret->methodState = METHOD_DONE;
318 ret->decision = DECISION_FAIL;
319 ret->allowNotifications = FALSE;
320 wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Auth-Reject");
321 return eap_sake_build_msg(data, id, 0,
322 EAP_SAKE_SUBTYPE_AUTH_REJECT);
324 if (os_memcmp_const(attr.mic_s, mic_s, EAP_SAKE_MIC_LEN) != 0) {
325 wpa_printf(MSG_INFO, "EAP-SAKE: Incorrect AT_MIC_S");
326 eap_sake_state(data, FAILURE);
327 ret->methodState = METHOD_DONE;
328 ret->decision = DECISION_FAIL;
329 ret->allowNotifications = FALSE;
330 wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending "
331 "Response/Auth-Reject");
332 return eap_sake_build_msg(data, id, 0,
333 EAP_SAKE_SUBTYPE_AUTH_REJECT);
336 wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Confirm");
338 resp = eap_sake_build_msg(data, id, 2 + EAP_SAKE_MIC_LEN,
339 EAP_SAKE_SUBTYPE_CONFIRM);
343 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_MIC_P");
344 wpabuf_put_u8(resp, EAP_SAKE_AT_MIC_P);
345 wpabuf_put_u8(resp, 2 + EAP_SAKE_MIC_LEN);
346 rpos = wpabuf_put(resp, EAP_SAKE_MIC_LEN);
347 if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
348 data->serverid, data->serverid_len,
349 data->peerid, data->peerid_len, 1,
350 wpabuf_head(resp), wpabuf_len(resp), rpos,
352 wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
357 eap_sake_state(data, SUCCESS);
358 ret->methodState = METHOD_DONE;
359 ret->decision = DECISION_UNCOND_SUCC;
360 ret->allowNotifications = FALSE;
366 static struct wpabuf * eap_sake_process(struct eap_sm *sm, void *priv,
367 struct eap_method_ret *ret,
368 const struct wpabuf *reqData)
370 struct eap_sake_data *data = priv;
371 const struct eap_sake_hdr *req;
375 u8 subtype, session_id, id;
377 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SAKE, reqData, &len);
378 if (pos == NULL || len < sizeof(struct eap_sake_hdr)) {
383 req = (const struct eap_sake_hdr *) pos;
385 id = eap_get_id(reqData);
386 subtype = req->subtype;
387 session_id = req->session_id;
388 pos = (const u8 *) (req + 1);
390 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received frame: subtype %d "
391 "session_id %d", subtype, session_id);
392 wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Received attributes",
395 if (data->session_id_set && data->session_id != session_id) {
396 wpa_printf(MSG_INFO, "EAP-SAKE: Session ID mismatch (%d,%d)",
397 session_id, data->session_id);
401 data->session_id = session_id;
402 data->session_id_set = 1;
405 ret->methodState = METHOD_MAY_CONT;
406 ret->decision = DECISION_FAIL;
407 ret->allowNotifications = TRUE;
410 case EAP_SAKE_SUBTYPE_IDENTITY:
411 resp = eap_sake_process_identity(sm, data, ret, id,
414 case EAP_SAKE_SUBTYPE_CHALLENGE:
415 resp = eap_sake_process_challenge(sm, data, ret, id,
418 case EAP_SAKE_SUBTYPE_CONFIRM:
419 resp = eap_sake_process_confirm(sm, data, ret, id, reqData,
423 wpa_printf(MSG_DEBUG, "EAP-SAKE: Ignoring message with "
424 "unknown subtype %d", subtype);
429 if (ret->methodState == METHOD_DONE)
430 ret->allowNotifications = FALSE;
436 static Boolean eap_sake_isKeyAvailable(struct eap_sm *sm, void *priv)
438 struct eap_sake_data *data = priv;
439 return data->state == SUCCESS;
443 static u8 * eap_sake_getKey(struct eap_sm *sm, void *priv, size_t *len)
445 struct eap_sake_data *data = priv;
448 if (data->state != SUCCESS)
451 key = os_memdup(data->msk, EAP_MSK_LEN);
460 static u8 * eap_sake_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
462 struct eap_sake_data *data = priv;
465 if (data->state != SUCCESS)
468 *len = 1 + 2 * EAP_SAKE_RAND_LEN;
469 id = os_malloc(*len);
473 id[0] = EAP_TYPE_SAKE;
474 os_memcpy(id + 1, data->rand_s, EAP_SAKE_RAND_LEN);
475 os_memcpy(id + 1 + EAP_SAKE_RAND_LEN, data->rand_s, EAP_SAKE_RAND_LEN);
476 wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Derived Session-Id", id, *len);
482 static u8 * eap_sake_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
484 struct eap_sake_data *data = priv;
487 if (data->state != SUCCESS)
490 key = os_memdup(data->emsk, EAP_EMSK_LEN);
499 int eap_peer_sake_register(void)
501 struct eap_method *eap;
503 eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
504 EAP_VENDOR_IETF, EAP_TYPE_SAKE, "SAKE");
508 eap->init = eap_sake_init;
509 eap->deinit = eap_sake_deinit;
510 eap->process = eap_sake_process;
511 eap->isKeyAvailable = eap_sake_isKeyAvailable;
512 eap->getKey = eap_sake_getKey;
513 eap->getSessionId = eap_sake_get_session_id;
514 eap->get_emsk = eap_sake_get_emsk;
516 return eap_peer_method_register(eap);