2 * hostapd / EAP-SAKE (RFC 4763) server
3 * Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
18 #include "eap_server/eap_i.h"
19 #include "eap_common/eap_sake_common.h"
22 struct eap_sake_data {
23 enum { IDENTITY, CHALLENGE, CONFIRM, SUCCESS, FAILURE } state;
24 u8 rand_s[EAP_SAKE_RAND_LEN];
25 u8 rand_p[EAP_SAKE_RAND_LEN];
27 u8 auth[EAP_SAKE_TEK_AUTH_LEN];
28 u8 cipher[EAP_SAKE_TEK_CIPHER_LEN];
31 u8 emsk[EAP_EMSK_LEN];
40 static const char * eap_sake_state_txt(int state)
59 static void eap_sake_state(struct eap_sake_data *data, int state)
61 wpa_printf(MSG_DEBUG, "EAP-SAKE: %s -> %s",
62 eap_sake_state_txt(data->state),
63 eap_sake_state_txt(state));
68 static void * eap_sake_init(struct eap_sm *sm)
70 struct eap_sake_data *data;
72 data = os_zalloc(sizeof(*data));
75 data->state = CHALLENGE;
77 if (os_get_random(&data->session_id, 1)) {
78 wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to get random data");
82 wpa_printf(MSG_DEBUG, "EAP-SAKE: Initialized Session ID %d",
85 /* TODO: add support for configuring SERVERID */
86 data->serverid = (u8 *) os_strdup("hostapd");
88 data->serverid_len = os_strlen((char *) data->serverid);
94 static void eap_sake_reset(struct eap_sm *sm, void *priv)
96 struct eap_sake_data *data = priv;
97 os_free(data->serverid);
98 os_free(data->peerid);
103 static struct wpabuf * eap_sake_build_msg(struct eap_sake_data *data,
104 u8 id, size_t length, u8 subtype)
106 struct eap_sake_hdr *sake;
110 plen = sizeof(struct eap_sake_hdr) + length;
112 msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_SAKE, plen,
113 EAP_CODE_REQUEST, id);
115 wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to allocate memory "
120 sake = wpabuf_put(msg, sizeof(*sake));
121 sake->version = EAP_SAKE_VERSION;
122 sake->session_id = data->session_id;
123 sake->subtype = subtype;
129 static struct wpabuf * eap_sake_build_identity(struct eap_sm *sm,
130 struct eap_sake_data *data,
136 wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Identity");
140 plen += 2 + data->serverid_len;
141 msg = eap_sake_build_msg(data, id, plen, EAP_SAKE_SUBTYPE_IDENTITY);
143 data->state = FAILURE;
147 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_PERM_ID_REQ");
148 eap_sake_add_attr(msg, EAP_SAKE_AT_PERM_ID_REQ, NULL, 2);
150 if (data->serverid) {
151 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_SERVERID");
152 eap_sake_add_attr(msg, EAP_SAKE_AT_SERVERID,
153 data->serverid, data->serverid_len);
160 static struct wpabuf * eap_sake_build_challenge(struct eap_sm *sm,
161 struct eap_sake_data *data,
167 wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Challenge");
169 if (os_get_random(data->rand_s, EAP_SAKE_RAND_LEN)) {
170 wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to get random data");
171 data->state = FAILURE;
174 wpa_hexdump(MSG_MSGDUMP, "EAP-SAKE: RAND_S (server rand)",
175 data->rand_s, EAP_SAKE_RAND_LEN);
177 plen = 2 + EAP_SAKE_RAND_LEN;
179 plen += 2 + data->serverid_len;
180 msg = eap_sake_build_msg(data, id, plen, EAP_SAKE_SUBTYPE_CHALLENGE);
182 data->state = FAILURE;
186 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_RAND_S");
187 eap_sake_add_attr(msg, EAP_SAKE_AT_RAND_S,
188 data->rand_s, EAP_SAKE_RAND_LEN);
190 if (data->serverid) {
191 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_SERVERID");
192 eap_sake_add_attr(msg, EAP_SAKE_AT_SERVERID,
193 data->serverid, data->serverid_len);
200 static struct wpabuf * eap_sake_build_confirm(struct eap_sm *sm,
201 struct eap_sake_data *data,
207 wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Confirm");
209 msg = eap_sake_build_msg(data, id, 2 + EAP_SAKE_MIC_LEN,
210 EAP_SAKE_SUBTYPE_CONFIRM);
212 data->state = FAILURE;
216 wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_MIC_S");
217 wpabuf_put_u8(msg, EAP_SAKE_AT_MIC_S);
218 wpabuf_put_u8(msg, 2 + EAP_SAKE_MIC_LEN);
219 mic = wpabuf_put(msg, EAP_SAKE_MIC_LEN);
220 if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
221 data->serverid, data->serverid_len,
222 data->peerid, data->peerid_len, 0,
223 wpabuf_head(msg), wpabuf_len(msg), mic, mic))
225 wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
226 data->state = FAILURE;
235 static struct wpabuf * eap_sake_buildReq(struct eap_sm *sm, void *priv, u8 id)
237 struct eap_sake_data *data = priv;
239 switch (data->state) {
241 return eap_sake_build_identity(sm, data, id);
243 return eap_sake_build_challenge(sm, data, id);
245 return eap_sake_build_confirm(sm, data, id);
247 wpa_printf(MSG_DEBUG, "EAP-SAKE: Unknown state %d in buildReq",
255 static Boolean eap_sake_check(struct eap_sm *sm, void *priv,
256 struct wpabuf *respData)
258 struct eap_sake_data *data = priv;
259 struct eap_sake_hdr *resp;
261 u8 version, session_id, subtype;
264 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SAKE, respData, &len);
265 if (pos == NULL || len < sizeof(struct eap_sake_hdr)) {
266 wpa_printf(MSG_INFO, "EAP-SAKE: Invalid frame");
270 resp = (struct eap_sake_hdr *) pos;
271 version = resp->version;
272 session_id = resp->session_id;
273 subtype = resp->subtype;
275 if (version != EAP_SAKE_VERSION) {
276 wpa_printf(MSG_INFO, "EAP-SAKE: Unknown version %d", version);
280 if (session_id != data->session_id) {
281 wpa_printf(MSG_INFO, "EAP-SAKE: Session ID mismatch (%d,%d)",
282 session_id, data->session_id);
286 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received frame: subtype=%d", subtype);
288 if (data->state == IDENTITY && subtype == EAP_SAKE_SUBTYPE_IDENTITY)
291 if (data->state == CHALLENGE && subtype == EAP_SAKE_SUBTYPE_CHALLENGE)
294 if (data->state == CONFIRM && subtype == EAP_SAKE_SUBTYPE_CONFIRM)
297 if (subtype == EAP_SAKE_SUBTYPE_AUTH_REJECT)
300 wpa_printf(MSG_INFO, "EAP-SAKE: Unexpected subtype=%d in state=%d",
301 subtype, data->state);
307 static void eap_sake_process_identity(struct eap_sm *sm,
308 struct eap_sake_data *data,
309 const struct wpabuf *respData,
310 const u8 *payload, size_t payloadlen)
312 if (data->state != IDENTITY)
315 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Identity");
316 /* TODO: update identity and select new user data */
317 eap_sake_state(data, CHALLENGE);
321 static void eap_sake_process_challenge(struct eap_sm *sm,
322 struct eap_sake_data *data,
323 const struct wpabuf *respData,
324 const u8 *payload, size_t payloadlen)
326 struct eap_sake_parse_attr attr;
327 u8 mic_p[EAP_SAKE_MIC_LEN];
329 if (data->state != CHALLENGE)
332 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Challenge");
334 if (eap_sake_parse_attributes(payload, payloadlen, &attr))
337 if (!attr.rand_p || !attr.mic_p) {
338 wpa_printf(MSG_INFO, "EAP-SAKE: Response/Challenge did not "
339 "include AT_RAND_P or AT_MIC_P");
343 os_memcpy(data->rand_p, attr.rand_p, EAP_SAKE_RAND_LEN);
345 os_free(data->peerid);
347 data->peerid_len = 0;
349 data->peerid = os_malloc(attr.peerid_len);
350 if (data->peerid == NULL)
352 os_memcpy(data->peerid, attr.peerid, attr.peerid_len);
353 data->peerid_len = attr.peerid_len;
356 if (sm->user == NULL || sm->user->password == NULL ||
357 sm->user->password_len != 2 * EAP_SAKE_ROOT_SECRET_LEN) {
358 wpa_printf(MSG_INFO, "EAP-SAKE: Plaintext password with "
359 "%d-byte key not configured",
360 2 * EAP_SAKE_ROOT_SECRET_LEN);
361 data->state = FAILURE;
364 eap_sake_derive_keys(sm->user->password,
365 sm->user->password + EAP_SAKE_ROOT_SECRET_LEN,
366 data->rand_s, data->rand_p,
367 (u8 *) &data->tek, data->msk, data->emsk);
369 eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
370 data->serverid, data->serverid_len,
371 data->peerid, data->peerid_len, 1,
372 wpabuf_head(respData), wpabuf_len(respData),
374 if (os_memcmp(attr.mic_p, mic_p, EAP_SAKE_MIC_LEN) != 0) {
375 wpa_printf(MSG_INFO, "EAP-SAKE: Incorrect AT_MIC_P");
376 eap_sake_state(data, FAILURE);
380 eap_sake_state(data, CONFIRM);
384 static void eap_sake_process_confirm(struct eap_sm *sm,
385 struct eap_sake_data *data,
386 const struct wpabuf *respData,
387 const u8 *payload, size_t payloadlen)
389 struct eap_sake_parse_attr attr;
390 u8 mic_p[EAP_SAKE_MIC_LEN];
392 if (data->state != CONFIRM)
395 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Confirm");
397 if (eap_sake_parse_attributes(payload, payloadlen, &attr))
401 wpa_printf(MSG_INFO, "EAP-SAKE: Response/Confirm did not "
406 eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
407 data->serverid, data->serverid_len,
408 data->peerid, data->peerid_len, 1,
409 wpabuf_head(respData), wpabuf_len(respData),
411 if (os_memcmp(attr.mic_p, mic_p, EAP_SAKE_MIC_LEN) != 0) {
412 wpa_printf(MSG_INFO, "EAP-SAKE: Incorrect AT_MIC_P");
413 eap_sake_state(data, FAILURE);
415 eap_sake_state(data, SUCCESS);
419 static void eap_sake_process_auth_reject(struct eap_sm *sm,
420 struct eap_sake_data *data,
421 const struct wpabuf *respData,
422 const u8 *payload, size_t payloadlen)
424 wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Auth-Reject");
425 eap_sake_state(data, FAILURE);
429 static void eap_sake_process(struct eap_sm *sm, void *priv,
430 struct wpabuf *respData)
432 struct eap_sake_data *data = priv;
433 struct eap_sake_hdr *resp;
438 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SAKE, respData, &len);
439 if (pos == NULL || len < sizeof(struct eap_sake_hdr))
442 resp = (struct eap_sake_hdr *) pos;
444 subtype = resp->subtype;
445 pos = (u8 *) (resp + 1);
447 wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Received attributes",
451 case EAP_SAKE_SUBTYPE_IDENTITY:
452 eap_sake_process_identity(sm, data, respData, pos, end - pos);
454 case EAP_SAKE_SUBTYPE_CHALLENGE:
455 eap_sake_process_challenge(sm, data, respData, pos, end - pos);
457 case EAP_SAKE_SUBTYPE_CONFIRM:
458 eap_sake_process_confirm(sm, data, respData, pos, end - pos);
460 case EAP_SAKE_SUBTYPE_AUTH_REJECT:
461 eap_sake_process_auth_reject(sm, data, respData, pos,
468 static Boolean eap_sake_isDone(struct eap_sm *sm, void *priv)
470 struct eap_sake_data *data = priv;
471 return data->state == SUCCESS || data->state == FAILURE;
475 static u8 * eap_sake_getKey(struct eap_sm *sm, void *priv, size_t *len)
477 struct eap_sake_data *data = priv;
480 if (data->state != SUCCESS)
483 key = os_malloc(EAP_MSK_LEN);
486 os_memcpy(key, data->msk, EAP_MSK_LEN);
493 static u8 * eap_sake_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
495 struct eap_sake_data *data = priv;
498 if (data->state != SUCCESS)
501 key = os_malloc(EAP_EMSK_LEN);
504 os_memcpy(key, data->emsk, EAP_EMSK_LEN);
511 static Boolean eap_sake_isSuccess(struct eap_sm *sm, void *priv)
513 struct eap_sake_data *data = priv;
514 return data->state == SUCCESS;
518 int eap_server_sake_register(void)
520 struct eap_method *eap;
523 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
524 EAP_VENDOR_IETF, EAP_TYPE_SAKE, "SAKE");
528 eap->init = eap_sake_init;
529 eap->reset = eap_sake_reset;
530 eap->buildReq = eap_sake_buildReq;
531 eap->check = eap_sake_check;
532 eap->process = eap_sake_process;
533 eap->isDone = eap_sake_isDone;
534 eap->getKey = eap_sake_getKey;
535 eap->isSuccess = eap_sake_isSuccess;
536 eap->get_emsk = eap_sake_get_emsk;
538 ret = eap_server_method_register(eap);
540 eap_server_method_free(eap);