2 * hostapd / EAP-SAKE (RFC 4763) server
3 * Copyright (c) 2006-2007, 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_server/eap_i.h"
14 #include "eap_common/eap_sake_common.h"
17 struct eap_sake_data {
18 enum { IDENTITY, CHALLENGE, CONFIRM, SUCCESS, FAILURE } state;
19 u8 rand_s[EAP_SAKE_RAND_LEN];
20 u8 rand_p[EAP_SAKE_RAND_LEN];
22 u8 auth[EAP_SAKE_TEK_AUTH_LEN];
23 u8 cipher[EAP_SAKE_TEK_CIPHER_LEN];
26 u8 emsk[EAP_EMSK_LEN];
33 static const char * eap_sake_state_txt(int state)
52 static void eap_sake_state(struct eap_sake_data *data, int state)
54 wpa_printf(MSG_DEBUG, "EAP-SAKE: %s -> %s",
55 eap_sake_state_txt(data->state),
56 eap_sake_state_txt(state));
61 static void * eap_sake_init(struct eap_sm *sm)
63 struct eap_sake_data *data;
65 data = os_zalloc(sizeof(*data));
68 data->state = CHALLENGE;
70 if (os_get_random(&data->session_id, 1)) {
71 wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to get random data");
75 wpa_printf(MSG_DEBUG, "EAP-SAKE: Initialized Session ID %d",
82 static void eap_sake_reset(struct eap_sm *sm, void *priv)
84 struct eap_sake_data *data = priv;
85 os_free(data->peerid);
86 bin_clear_free(data, sizeof(*data));
90 static struct wpabuf * eap_sake_build_msg(struct eap_sake_data *data,
91 u8 id, size_t length, u8 subtype)
93 struct eap_sake_hdr *sake;
97 plen = sizeof(struct eap_sake_hdr) + length;
99 msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_SAKE, plen,
100 EAP_CODE_REQUEST, id);
102 wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to allocate memory "
107 sake = wpabuf_put(msg, sizeof(*sake));
108 sake->version = EAP_SAKE_VERSION;
109 sake->session_id = data->session_id;
110 sake->subtype = subtype;
116 static struct wpabuf * eap_sake_build_identity(struct eap_sm *sm,
117 struct eap_sake_data *data,
123 wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Identity");
126 plen += 2 + sm->server_id_len;
127 msg = eap_sake_build_msg(data, id, plen, EAP_SAKE_SUBTYPE_IDENTITY);
129 data->state = FAILURE;
133 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_PERM_ID_REQ");
134 eap_sake_add_attr(msg, EAP_SAKE_AT_PERM_ID_REQ, NULL, 2);
136 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_SERVERID");
137 eap_sake_add_attr(msg, EAP_SAKE_AT_SERVERID,
138 sm->server_id, sm->server_id_len);
144 static struct wpabuf * eap_sake_build_challenge(struct eap_sm *sm,
145 struct eap_sake_data *data,
151 wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Challenge");
153 if (random_get_bytes(data->rand_s, EAP_SAKE_RAND_LEN)) {
154 wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to get random data");
155 data->state = FAILURE;
158 wpa_hexdump(MSG_MSGDUMP, "EAP-SAKE: RAND_S (server rand)",
159 data->rand_s, EAP_SAKE_RAND_LEN);
161 plen = 2 + EAP_SAKE_RAND_LEN + 2 + sm->server_id_len;
162 msg = eap_sake_build_msg(data, id, plen, EAP_SAKE_SUBTYPE_CHALLENGE);
164 data->state = FAILURE;
168 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_RAND_S");
169 eap_sake_add_attr(msg, EAP_SAKE_AT_RAND_S,
170 data->rand_s, EAP_SAKE_RAND_LEN);
172 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_SERVERID");
173 eap_sake_add_attr(msg, EAP_SAKE_AT_SERVERID,
174 sm->server_id, sm->server_id_len);
180 static struct wpabuf * eap_sake_build_confirm(struct eap_sm *sm,
181 struct eap_sake_data *data,
187 wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Confirm");
189 msg = eap_sake_build_msg(data, id, 2 + EAP_SAKE_MIC_LEN,
190 EAP_SAKE_SUBTYPE_CONFIRM);
192 data->state = FAILURE;
196 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_MIC_S");
197 wpabuf_put_u8(msg, EAP_SAKE_AT_MIC_S);
198 wpabuf_put_u8(msg, 2 + EAP_SAKE_MIC_LEN);
199 mic = wpabuf_put(msg, EAP_SAKE_MIC_LEN);
200 if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
201 sm->server_id, sm->server_id_len,
202 data->peerid, data->peerid_len, 0,
203 wpabuf_head(msg), wpabuf_len(msg), mic, mic))
205 wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
206 data->state = FAILURE;
215 static struct wpabuf * eap_sake_buildReq(struct eap_sm *sm, void *priv, u8 id)
217 struct eap_sake_data *data = priv;
219 switch (data->state) {
221 return eap_sake_build_identity(sm, data, id);
223 return eap_sake_build_challenge(sm, data, id);
225 return eap_sake_build_confirm(sm, data, id);
227 wpa_printf(MSG_DEBUG, "EAP-SAKE: Unknown state %d in buildReq",
235 static Boolean eap_sake_check(struct eap_sm *sm, void *priv,
236 struct wpabuf *respData)
238 struct eap_sake_data *data = priv;
239 struct eap_sake_hdr *resp;
241 u8 version, session_id, subtype;
244 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SAKE, respData, &len);
245 if (pos == NULL || len < sizeof(struct eap_sake_hdr)) {
246 wpa_printf(MSG_INFO, "EAP-SAKE: Invalid frame");
250 resp = (struct eap_sake_hdr *) pos;
251 version = resp->version;
252 session_id = resp->session_id;
253 subtype = resp->subtype;
255 if (version != EAP_SAKE_VERSION) {
256 wpa_printf(MSG_INFO, "EAP-SAKE: Unknown version %d", version);
260 if (session_id != data->session_id) {
261 wpa_printf(MSG_INFO, "EAP-SAKE: Session ID mismatch (%d,%d)",
262 session_id, data->session_id);
266 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received frame: subtype=%d", subtype);
268 if (data->state == IDENTITY && subtype == EAP_SAKE_SUBTYPE_IDENTITY)
271 if (data->state == CHALLENGE && subtype == EAP_SAKE_SUBTYPE_CHALLENGE)
274 if (data->state == CONFIRM && subtype == EAP_SAKE_SUBTYPE_CONFIRM)
277 if (subtype == EAP_SAKE_SUBTYPE_AUTH_REJECT)
280 wpa_printf(MSG_INFO, "EAP-SAKE: Unexpected subtype=%d in state=%d",
281 subtype, data->state);
287 static void eap_sake_process_identity(struct eap_sm *sm,
288 struct eap_sake_data *data,
289 const struct wpabuf *respData,
290 const u8 *payload, size_t payloadlen)
292 if (data->state != IDENTITY)
295 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Identity");
296 /* TODO: update identity and select new user data */
297 eap_sake_state(data, CHALLENGE);
301 static void eap_sake_process_challenge(struct eap_sm *sm,
302 struct eap_sake_data *data,
303 const struct wpabuf *respData,
304 const u8 *payload, size_t payloadlen)
306 struct eap_sake_parse_attr attr;
307 u8 mic_p[EAP_SAKE_MIC_LEN];
309 if (data->state != CHALLENGE)
312 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Challenge");
314 if (eap_sake_parse_attributes(payload, payloadlen, &attr))
317 if (!attr.rand_p || !attr.mic_p) {
318 wpa_printf(MSG_INFO, "EAP-SAKE: Response/Challenge did not "
319 "include AT_RAND_P or AT_MIC_P");
323 os_memcpy(data->rand_p, attr.rand_p, EAP_SAKE_RAND_LEN);
325 os_free(data->peerid);
327 data->peerid_len = 0;
329 data->peerid = os_memdup(attr.peerid, attr.peerid_len);
330 if (data->peerid == NULL)
332 data->peerid_len = attr.peerid_len;
335 if (sm->user == NULL || sm->user->password == NULL ||
336 sm->user->password_len != 2 * EAP_SAKE_ROOT_SECRET_LEN) {
337 wpa_printf(MSG_INFO, "EAP-SAKE: Plaintext password with "
338 "%d-byte key not configured",
339 2 * EAP_SAKE_ROOT_SECRET_LEN);
340 data->state = FAILURE;
343 eap_sake_derive_keys(sm->user->password,
344 sm->user->password + EAP_SAKE_ROOT_SECRET_LEN,
345 data->rand_s, data->rand_p,
346 (u8 *) &data->tek, data->msk, data->emsk);
348 eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
349 sm->server_id, sm->server_id_len,
350 data->peerid, data->peerid_len, 1,
351 wpabuf_head(respData), wpabuf_len(respData),
353 if (os_memcmp_const(attr.mic_p, mic_p, EAP_SAKE_MIC_LEN) != 0) {
354 wpa_printf(MSG_INFO, "EAP-SAKE: Incorrect AT_MIC_P");
355 eap_sake_state(data, FAILURE);
359 eap_sake_state(data, CONFIRM);
363 static void eap_sake_process_confirm(struct eap_sm *sm,
364 struct eap_sake_data *data,
365 const struct wpabuf *respData,
366 const u8 *payload, size_t payloadlen)
368 struct eap_sake_parse_attr attr;
369 u8 mic_p[EAP_SAKE_MIC_LEN];
371 if (data->state != CONFIRM)
374 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Confirm");
376 if (eap_sake_parse_attributes(payload, payloadlen, &attr))
380 wpa_printf(MSG_INFO, "EAP-SAKE: Response/Confirm did not "
385 eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
386 sm->server_id, sm->server_id_len,
387 data->peerid, data->peerid_len, 1,
388 wpabuf_head(respData), wpabuf_len(respData),
390 if (os_memcmp_const(attr.mic_p, mic_p, EAP_SAKE_MIC_LEN) != 0) {
391 wpa_printf(MSG_INFO, "EAP-SAKE: Incorrect AT_MIC_P");
392 eap_sake_state(data, FAILURE);
394 eap_sake_state(data, SUCCESS);
398 static void eap_sake_process_auth_reject(struct eap_sm *sm,
399 struct eap_sake_data *data,
400 const struct wpabuf *respData,
401 const u8 *payload, size_t payloadlen)
403 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Auth-Reject");
404 eap_sake_state(data, FAILURE);
408 static void eap_sake_process(struct eap_sm *sm, void *priv,
409 struct wpabuf *respData)
411 struct eap_sake_data *data = priv;
412 struct eap_sake_hdr *resp;
417 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SAKE, respData, &len);
418 if (pos == NULL || len < sizeof(struct eap_sake_hdr))
421 resp = (struct eap_sake_hdr *) pos;
423 subtype = resp->subtype;
424 pos = (u8 *) (resp + 1);
426 wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Received attributes",
430 case EAP_SAKE_SUBTYPE_IDENTITY:
431 eap_sake_process_identity(sm, data, respData, pos, end - pos);
433 case EAP_SAKE_SUBTYPE_CHALLENGE:
434 eap_sake_process_challenge(sm, data, respData, pos, end - pos);
436 case EAP_SAKE_SUBTYPE_CONFIRM:
437 eap_sake_process_confirm(sm, data, respData, pos, end - pos);
439 case EAP_SAKE_SUBTYPE_AUTH_REJECT:
440 eap_sake_process_auth_reject(sm, data, respData, pos,
447 static Boolean eap_sake_isDone(struct eap_sm *sm, void *priv)
449 struct eap_sake_data *data = priv;
450 return data->state == SUCCESS || data->state == FAILURE;
454 static u8 * eap_sake_getKey(struct eap_sm *sm, void *priv, size_t *len)
456 struct eap_sake_data *data = priv;
459 if (data->state != SUCCESS)
462 key = os_memdup(data->msk, EAP_MSK_LEN);
471 static u8 * eap_sake_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
473 struct eap_sake_data *data = priv;
476 if (data->state != SUCCESS)
479 key = os_memdup(data->emsk, EAP_EMSK_LEN);
488 static Boolean eap_sake_isSuccess(struct eap_sm *sm, void *priv)
490 struct eap_sake_data *data = priv;
491 return data->state == SUCCESS;
495 static u8 * eap_sake_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
497 struct eap_sake_data *data = priv;
500 if (data->state != SUCCESS)
503 *len = 1 + 2 * EAP_SAKE_RAND_LEN;
504 id = os_malloc(*len);
508 id[0] = EAP_TYPE_SAKE;
509 os_memcpy(id + 1, data->rand_s, EAP_SAKE_RAND_LEN);
510 os_memcpy(id + 1 + EAP_SAKE_RAND_LEN, data->rand_s, EAP_SAKE_RAND_LEN);
511 wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Derived Session-Id", id, *len);
517 int eap_server_sake_register(void)
519 struct eap_method *eap;
521 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
522 EAP_VENDOR_IETF, EAP_TYPE_SAKE, "SAKE");
526 eap->init = eap_sake_init;
527 eap->reset = eap_sake_reset;
528 eap->buildReq = eap_sake_buildReq;
529 eap->check = eap_sake_check;
530 eap->process = eap_sake_process;
531 eap->isDone = eap_sake_isDone;
532 eap->getKey = eap_sake_getKey;
533 eap->isSuccess = eap_sake_isSuccess;
534 eap->get_emsk = eap_sake_get_emsk;
535 eap->getSessionId = eap_sake_get_session_id;
537 return eap_server_method_register(eap);