2 * EAP peer method: EAP-SAKE (RFC 4763)
3 * Copyright (c) 2006-2019, 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 if (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,
242 wpa_printf(MSG_INFO, "EAP-SAKE: Failed to derive keys");
246 wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Challenge");
248 rlen = 2 + EAP_SAKE_RAND_LEN + 2 + EAP_SAKE_MIC_LEN;
250 rlen += 2 + data->peerid_len;
251 resp = eap_sake_build_msg(data, id, rlen, EAP_SAKE_SUBTYPE_CHALLENGE);
255 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_RAND_P");
256 eap_sake_add_attr(resp, EAP_SAKE_AT_RAND_P,
257 data->rand_p, EAP_SAKE_RAND_LEN);
260 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_PEERID");
261 eap_sake_add_attr(resp, EAP_SAKE_AT_PEERID,
262 data->peerid, data->peerid_len);
265 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_MIC_P");
266 wpabuf_put_u8(resp, EAP_SAKE_AT_MIC_P);
267 wpabuf_put_u8(resp, 2 + EAP_SAKE_MIC_LEN);
268 rpos = wpabuf_put(resp, EAP_SAKE_MIC_LEN);
269 if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
270 data->serverid, data->serverid_len,
271 data->peerid, data->peerid_len, 1,
272 wpabuf_head(resp), wpabuf_len(resp), rpos,
274 wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
279 eap_sake_state(data, CONFIRM);
285 static struct wpabuf * eap_sake_process_confirm(struct eap_sm *sm,
286 struct eap_sake_data *data,
287 struct eap_method_ret *ret,
289 const struct wpabuf *reqData,
293 struct eap_sake_parse_attr attr;
294 u8 mic_s[EAP_SAKE_MIC_LEN];
298 if (data->state != CONFIRM) {
303 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Request/Confirm");
305 if (eap_sake_parse_attributes(payload, payload_len, &attr))
309 wpa_printf(MSG_INFO, "EAP-SAKE: Request/Confirm did not "
314 if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
315 data->serverid, data->serverid_len,
316 data->peerid, data->peerid_len, 0,
317 wpabuf_head(reqData), wpabuf_len(reqData),
318 attr.mic_s, mic_s)) {
319 wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
320 eap_sake_state(data, FAILURE);
321 ret->methodState = METHOD_DONE;
322 ret->decision = DECISION_FAIL;
323 ret->allowNotifications = FALSE;
324 wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Auth-Reject");
325 return eap_sake_build_msg(data, id, 0,
326 EAP_SAKE_SUBTYPE_AUTH_REJECT);
328 if (os_memcmp_const(attr.mic_s, mic_s, EAP_SAKE_MIC_LEN) != 0) {
329 wpa_printf(MSG_INFO, "EAP-SAKE: Incorrect AT_MIC_S");
330 eap_sake_state(data, FAILURE);
331 ret->methodState = METHOD_DONE;
332 ret->decision = DECISION_FAIL;
333 ret->allowNotifications = FALSE;
334 wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending "
335 "Response/Auth-Reject");
336 return eap_sake_build_msg(data, id, 0,
337 EAP_SAKE_SUBTYPE_AUTH_REJECT);
340 wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Confirm");
342 resp = eap_sake_build_msg(data, id, 2 + EAP_SAKE_MIC_LEN,
343 EAP_SAKE_SUBTYPE_CONFIRM);
347 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_MIC_P");
348 wpabuf_put_u8(resp, EAP_SAKE_AT_MIC_P);
349 wpabuf_put_u8(resp, 2 + EAP_SAKE_MIC_LEN);
350 rpos = wpabuf_put(resp, EAP_SAKE_MIC_LEN);
351 if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
352 data->serverid, data->serverid_len,
353 data->peerid, data->peerid_len, 1,
354 wpabuf_head(resp), wpabuf_len(resp), rpos,
356 wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
361 eap_sake_state(data, SUCCESS);
362 ret->methodState = METHOD_DONE;
363 ret->decision = DECISION_UNCOND_SUCC;
364 ret->allowNotifications = FALSE;
370 static struct wpabuf * eap_sake_process(struct eap_sm *sm, void *priv,
371 struct eap_method_ret *ret,
372 const struct wpabuf *reqData)
374 struct eap_sake_data *data = priv;
375 const struct eap_sake_hdr *req;
379 u8 subtype, session_id, id;
381 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SAKE, reqData, &len);
382 if (pos == NULL || len < sizeof(struct eap_sake_hdr)) {
387 req = (const struct eap_sake_hdr *) pos;
389 id = eap_get_id(reqData);
390 subtype = req->subtype;
391 session_id = req->session_id;
392 pos = (const u8 *) (req + 1);
394 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received frame: subtype %d "
395 "session_id %d", subtype, session_id);
396 wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Received attributes",
399 if (data->session_id_set && data->session_id != session_id) {
400 wpa_printf(MSG_INFO, "EAP-SAKE: Session ID mismatch (%d,%d)",
401 session_id, data->session_id);
405 data->session_id = session_id;
406 data->session_id_set = 1;
409 ret->methodState = METHOD_MAY_CONT;
410 ret->decision = DECISION_FAIL;
411 ret->allowNotifications = TRUE;
414 case EAP_SAKE_SUBTYPE_IDENTITY:
415 resp = eap_sake_process_identity(sm, data, ret, id,
418 case EAP_SAKE_SUBTYPE_CHALLENGE:
419 resp = eap_sake_process_challenge(sm, data, ret, id,
422 case EAP_SAKE_SUBTYPE_CONFIRM:
423 resp = eap_sake_process_confirm(sm, data, ret, id, reqData,
427 wpa_printf(MSG_DEBUG, "EAP-SAKE: Ignoring message with "
428 "unknown subtype %d", subtype);
433 if (ret->methodState == METHOD_DONE)
434 ret->allowNotifications = FALSE;
440 static Boolean eap_sake_isKeyAvailable(struct eap_sm *sm, void *priv)
442 struct eap_sake_data *data = priv;
443 return data->state == SUCCESS;
447 static u8 * eap_sake_getKey(struct eap_sm *sm, void *priv, size_t *len)
449 struct eap_sake_data *data = priv;
452 if (data->state != SUCCESS)
455 key = os_memdup(data->msk, EAP_MSK_LEN);
464 static u8 * eap_sake_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
466 struct eap_sake_data *data = priv;
469 if (data->state != SUCCESS)
472 *len = 1 + 2 * EAP_SAKE_RAND_LEN;
473 id = os_malloc(*len);
477 id[0] = EAP_TYPE_SAKE;
478 os_memcpy(id + 1, data->rand_s, EAP_SAKE_RAND_LEN);
479 os_memcpy(id + 1 + EAP_SAKE_RAND_LEN, data->rand_s, EAP_SAKE_RAND_LEN);
480 wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Derived Session-Id", id, *len);
486 static u8 * eap_sake_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
488 struct eap_sake_data *data = priv;
491 if (data->state != SUCCESS)
494 key = os_memdup(data->emsk, EAP_EMSK_LEN);
503 int eap_peer_sake_register(void)
505 struct eap_method *eap;
507 eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
508 EAP_VENDOR_IETF, EAP_TYPE_SAKE, "SAKE");
512 eap->init = eap_sake_init;
513 eap->deinit = eap_sake_deinit;
514 eap->process = eap_sake_process;
515 eap->isKeyAvailable = eap_sake_isKeyAvailable;
516 eap->getKey = eap_sake_getKey;
517 eap->getSessionId = eap_sake_get_session_id;
518 eap->get_emsk = eap_sake_get_emsk;
520 return eap_peer_method_register(eap);