2 * RSN pre-authentication (supplicant)
3 * Copyright (c) 2003-2012, Jouni Malinen <j@w1.fi>
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
14 #include "l2_packet/l2_packet.h"
15 #include "eapol_supp/eapol_supp_sm.h"
17 #include "pmksa_cache.h"
21 #if defined(IEEE8021X_EAPOL) && !defined(CONFIG_NO_WPA2)
23 #define PMKID_CANDIDATE_PRIO_SCAN 1000
26 struct rsn_pmksa_candidate {
34 * pmksa_candidate_free - Free all entries in PMKSA candidate list
35 * @sm: Pointer to WPA state machine data from wpa_sm_init()
37 void pmksa_candidate_free(struct wpa_sm *sm)
39 struct rsn_pmksa_candidate *entry, *n;
44 dl_list_for_each_safe(entry, n, &sm->pmksa_candidates,
45 struct rsn_pmksa_candidate, list) {
46 dl_list_del(&entry->list);
52 static void rsn_preauth_receive(void *ctx, const u8 *src_addr,
53 const u8 *buf, size_t len)
55 struct wpa_sm *sm = ctx;
57 wpa_printf(MSG_DEBUG, "RX pre-auth from " MACSTR, MAC2STR(src_addr));
58 wpa_hexdump(MSG_MSGDUMP, "RX pre-auth", buf, len);
60 if (sm->preauth_eapol == NULL ||
61 is_zero_ether_addr(sm->preauth_bssid) ||
62 os_memcmp(sm->preauth_bssid, src_addr, ETH_ALEN) != 0) {
63 wpa_printf(MSG_WARNING, "RSN pre-auth frame received from "
64 "unexpected source " MACSTR " - dropped",
69 eapol_sm_rx_eapol(sm->preauth_eapol, src_addr, buf, len);
73 static void rsn_preauth_eapol_cb(struct eapol_sm *eapol, int success,
76 struct wpa_sm *sm = ctx;
82 res = eapol_sm_get_key(eapol, pmk, PMK_LEN);
85 * EAP-LEAP is an exception from other EAP methods: it
86 * uses only 16-byte PMK.
88 res = eapol_sm_get_key(eapol, pmk, 16);
92 wpa_hexdump_key(MSG_DEBUG, "RSN: PMK from pre-auth",
94 sm->pmk_len = pmk_len;
95 pmksa_cache_add(sm->pmksa, pmk, pmk_len,
96 sm->preauth_bssid, sm->own_addr,
98 WPA_KEY_MGMT_IEEE8021X);
100 wpa_msg(sm->ctx->msg_ctx, MSG_INFO,
101 "RSN: failed to get master session key from "
102 "pre-auth EAPOL state machines");
107 wpa_msg(sm->ctx->msg_ctx, MSG_INFO, "RSN: pre-authentication with "
108 MACSTR " %s", MAC2STR(sm->preauth_bssid),
109 success ? "completed successfully" : "failed");
111 rsn_preauth_deinit(sm);
112 rsn_preauth_candidate_process(sm);
116 static void rsn_preauth_timeout(void *eloop_ctx, void *timeout_ctx)
118 struct wpa_sm *sm = eloop_ctx;
120 wpa_msg(sm->ctx->msg_ctx, MSG_INFO, "RSN: pre-authentication with "
121 MACSTR " timed out", MAC2STR(sm->preauth_bssid));
122 rsn_preauth_deinit(sm);
123 rsn_preauth_candidate_process(sm);
127 static int rsn_preauth_eapol_send(void *ctx, int type, const u8 *buf,
130 struct wpa_sm *sm = ctx;
135 /* TODO: could add l2_packet_sendmsg that allows fragments to avoid
138 if (sm->l2_preauth == NULL)
141 msg = wpa_sm_alloc_eapol(sm, type, buf, len, &msglen, NULL);
145 wpa_hexdump(MSG_MSGDUMP, "TX EAPOL (preauth)", msg, msglen);
146 res = l2_packet_send(sm->l2_preauth, sm->preauth_bssid,
147 ETH_P_RSN_PREAUTH, msg, msglen);
154 * rsn_preauth_init - Start new RSN pre-authentication
155 * @sm: Pointer to WPA state machine data from wpa_sm_init()
156 * @dst: Authenticator address (BSSID) with which to preauthenticate
157 * @eap_conf: Current EAP configuration
158 * Returns: 0 on success, -1 on another pre-authentication is in progress,
159 * -2 on layer 2 packet initialization failure, -3 on EAPOL state machine
160 * initialization failure, -4 on memory allocation failure
162 * This function request an RSN pre-authentication with a given destination
163 * address. This is usually called for PMKSA candidates found from scan results
164 * or from driver reports. In addition, ctrl_iface PREAUTH command can trigger
165 * pre-authentication.
167 int rsn_preauth_init(struct wpa_sm *sm, const u8 *dst,
168 struct eap_peer_config *eap_conf)
170 struct eapol_config eapol_conf;
171 struct eapol_ctx *ctx;
173 if (sm->preauth_eapol)
176 wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG,
177 "RSN: starting pre-authentication with " MACSTR, MAC2STR(dst));
179 sm->l2_preauth = l2_packet_init(sm->ifname, sm->own_addr,
181 rsn_preauth_receive, sm, 0);
182 if (sm->l2_preauth == NULL) {
183 wpa_printf(MSG_WARNING, "RSN: Failed to initialize L2 packet "
184 "processing for pre-authentication");
188 if (sm->bridge_ifname) {
189 sm->l2_preauth_br = l2_packet_init(sm->bridge_ifname,
192 rsn_preauth_receive, sm, 0);
193 if (sm->l2_preauth_br == NULL) {
194 wpa_printf(MSG_WARNING, "RSN: Failed to initialize L2 "
195 "packet processing (bridge) for "
196 "pre-authentication");
201 ctx = os_zalloc(sizeof(*ctx));
203 wpa_printf(MSG_WARNING, "Failed to allocate EAPOL context.");
206 ctx->ctx = sm->ctx->ctx;
207 ctx->msg_ctx = sm->ctx->ctx;
209 ctx->cb = rsn_preauth_eapol_cb;
211 ctx->scard_ctx = sm->scard_ctx;
212 ctx->eapol_send = rsn_preauth_eapol_send;
213 ctx->eapol_send_ctx = sm;
214 ctx->set_config_blob = sm->ctx->set_config_blob;
215 ctx->get_config_blob = sm->ctx->get_config_blob;
217 sm->preauth_eapol = eapol_sm_init(ctx);
218 if (sm->preauth_eapol == NULL) {
220 wpa_printf(MSG_WARNING, "RSN: Failed to initialize EAPOL "
221 "state machines for pre-authentication");
224 os_memset(&eapol_conf, 0, sizeof(eapol_conf));
225 eapol_conf.accept_802_1x_keys = 0;
226 eapol_conf.required_keys = 0;
227 eapol_conf.fast_reauth = sm->fast_reauth;
228 eapol_conf.workaround = sm->eap_workaround;
229 eapol_sm_notify_config(sm->preauth_eapol, eap_conf, &eapol_conf);
231 * Use a shorter startPeriod with preauthentication since the first
232 * preauth EAPOL-Start frame may end up being dropped due to race
233 * condition in the AP between the data receive and key configuration
234 * after the 4-Way Handshake.
236 eapol_sm_configure(sm->preauth_eapol, -1, -1, 5, 6);
237 os_memcpy(sm->preauth_bssid, dst, ETH_ALEN);
239 eapol_sm_notify_portValid(sm->preauth_eapol, TRUE);
240 /* 802.1X::portControl = Auto */
241 eapol_sm_notify_portEnabled(sm->preauth_eapol, TRUE);
243 eloop_register_timeout(sm->dot11RSNAConfigSATimeout, 0,
244 rsn_preauth_timeout, sm, NULL);
251 * rsn_preauth_deinit - Abort RSN pre-authentication
252 * @sm: Pointer to WPA state machine data from wpa_sm_init()
254 * This function aborts the current RSN pre-authentication (if one is started)
255 * and frees resources allocated for it.
257 void rsn_preauth_deinit(struct wpa_sm *sm)
259 if (sm == NULL || !sm->preauth_eapol)
262 eloop_cancel_timeout(rsn_preauth_timeout, sm, NULL);
263 eapol_sm_deinit(sm->preauth_eapol);
264 sm->preauth_eapol = NULL;
265 os_memset(sm->preauth_bssid, 0, ETH_ALEN);
267 l2_packet_deinit(sm->l2_preauth);
268 sm->l2_preauth = NULL;
269 if (sm->l2_preauth_br) {
270 l2_packet_deinit(sm->l2_preauth_br);
271 sm->l2_preauth_br = NULL;
277 * rsn_preauth_candidate_process - Process PMKSA candidates
278 * @sm: Pointer to WPA state machine data from wpa_sm_init()
280 * Go through the PMKSA candidates and start pre-authentication if a candidate
281 * without an existing PMKSA cache entry is found. Processed candidates will be
282 * removed from the list.
284 void rsn_preauth_candidate_process(struct wpa_sm *sm)
286 struct rsn_pmksa_candidate *candidate, *n;
288 if (dl_list_empty(&sm->pmksa_candidates))
291 /* TODO: drop priority for old candidate entries */
293 wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: processing PMKSA candidate "
295 if (sm->preauth_eapol ||
296 sm->proto != WPA_PROTO_RSN ||
297 wpa_sm_get_state(sm) != WPA_COMPLETED ||
298 (sm->key_mgmt != WPA_KEY_MGMT_IEEE8021X &&
299 sm->key_mgmt != WPA_KEY_MGMT_IEEE8021X_SHA256)) {
300 wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: not in suitable "
301 "state for new pre-authentication");
302 return; /* invalid state for new pre-auth */
305 dl_list_for_each_safe(candidate, n, &sm->pmksa_candidates,
306 struct rsn_pmksa_candidate, list) {
307 struct rsn_pmksa_cache_entry *p = NULL;
308 p = pmksa_cache_get(sm->pmksa, candidate->bssid, NULL, NULL);
309 if (os_memcmp(sm->bssid, candidate->bssid, ETH_ALEN) != 0 &&
310 (p == NULL || p->opportunistic)) {
311 wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: PMKSA "
313 " selected for pre-authentication",
314 MAC2STR(candidate->bssid));
315 dl_list_del(&candidate->list);
316 rsn_preauth_init(sm, candidate->bssid,
321 wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: PMKSA candidate "
322 MACSTR " does not need pre-authentication anymore",
323 MAC2STR(candidate->bssid));
324 /* Some drivers (e.g., NDIS) expect to get notified about the
325 * PMKIDs again, so report the existing data now. */
327 wpa_sm_add_pmkid(sm, candidate->bssid, p->pmkid);
330 dl_list_del(&candidate->list);
333 wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: no more pending PMKSA "
339 * pmksa_candidate_add - Add a new PMKSA candidate
340 * @sm: Pointer to WPA state machine data from wpa_sm_init()
341 * @bssid: BSSID (authenticator address) of the candidate
342 * @prio: Priority (the smaller number, the higher priority)
343 * @preauth: Whether the candidate AP advertises support for pre-authentication
345 * This function is used to add PMKSA candidates for RSN pre-authentication. It
346 * is called from scan result processing and from driver events for PMKSA
347 * candidates, i.e., EVENT_PMKID_CANDIDATE events to wpa_supplicant_event().
349 void pmksa_candidate_add(struct wpa_sm *sm, const u8 *bssid,
350 int prio, int preauth)
352 struct rsn_pmksa_candidate *cand, *pos;
354 if (sm->network_ctx && sm->proactive_key_caching)
355 pmksa_cache_get_opportunistic(sm->pmksa, sm->network_ctx,
359 wpa_printf(MSG_DEBUG, "RSN: Ignored PMKID candidate without "
364 /* If BSSID already on candidate list, update the priority of the old
365 * entry. Do not override priority based on normal scan results. */
367 dl_list_for_each(pos, &sm->pmksa_candidates,
368 struct rsn_pmksa_candidate, list) {
369 if (os_memcmp(pos->bssid, bssid, ETH_ALEN) == 0) {
376 dl_list_del(&cand->list);
377 if (prio < PMKID_CANDIDATE_PRIO_SCAN)
378 cand->priority = prio;
380 cand = os_zalloc(sizeof(*cand));
383 os_memcpy(cand->bssid, bssid, ETH_ALEN);
384 cand->priority = prio;
387 /* Add candidate to the list; order by increasing priority value. i.e.,
388 * highest priority (smallest value) first. */
389 dl_list_for_each(pos, &sm->pmksa_candidates,
390 struct rsn_pmksa_candidate, list) {
391 if (cand->priority <= pos->priority) {
392 dl_list_add(pos->list.prev, &cand->list);
398 dl_list_add_tail(&sm->pmksa_candidates, &cand->list);
400 wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: added PMKSA cache "
401 "candidate " MACSTR " prio %d", MAC2STR(bssid), prio);
402 rsn_preauth_candidate_process(sm);
406 /* TODO: schedule periodic scans if current AP supports preauth */
409 * rsn_preauth_scan_results - Start processing scan results for canditates
410 * @sm: Pointer to WPA state machine data from wpa_sm_init()
411 * Returns: 0 if ready to process results or -1 to skip processing
413 * This functions is used to notify RSN code about start of new scan results
414 * processing. The actual scan results will be provided by calling
415 * rsn_preauth_scan_result() for each BSS if this function returned 0.
417 int rsn_preauth_scan_results(struct wpa_sm *sm)
419 if (sm->ssid_len == 0)
423 * TODO: is it ok to free all candidates? What about the entries
424 * received from EVENT_PMKID_CANDIDATE?
426 pmksa_candidate_free(sm);
433 * rsn_preauth_scan_result - Processing scan result for PMKSA canditates
434 * @sm: Pointer to WPA state machine data from wpa_sm_init()
436 * Add all suitable APs (Authenticators) from scan results into PMKSA
439 void rsn_preauth_scan_result(struct wpa_sm *sm, const u8 *bssid,
440 const u8 *ssid, const u8 *rsn)
442 struct wpa_ie_data ie;
443 struct rsn_pmksa_cache_entry *pmksa;
445 if (ssid[1] != sm->ssid_len ||
446 os_memcmp(ssid + 2, sm->ssid, sm->ssid_len) != 0)
447 return; /* Not for the current SSID */
449 if (os_memcmp(bssid, sm->bssid, ETH_ALEN) == 0)
450 return; /* Ignore current AP */
452 if (wpa_parse_wpa_ie(rsn, 2 + rsn[1], &ie))
455 pmksa = pmksa_cache_get(sm->pmksa, bssid, NULL, NULL);
456 if (pmksa && (!pmksa->opportunistic ||
457 !(ie.capabilities & WPA_CAPABILITY_PREAUTH)))
460 /* Give less priority to candidates found from normal scan results. */
461 pmksa_candidate_add(sm, bssid, PMKID_CANDIDATE_PRIO_SCAN,
462 ie.capabilities & WPA_CAPABILITY_PREAUTH);
466 #ifdef CONFIG_CTRL_IFACE
468 * rsn_preauth_get_status - Get pre-authentication status
469 * @sm: Pointer to WPA state machine data from wpa_sm_init()
470 * @buf: Buffer for status information
471 * @buflen: Maximum buffer length
472 * @verbose: Whether to include verbose status information
473 * Returns: Number of bytes written to buf.
475 * Query WPA2 pre-authentication for status information. This function fills in
476 * a text area with current status information. If the buffer (buf) is not
477 * large enough, status information will be truncated to fit the buffer.
479 int rsn_preauth_get_status(struct wpa_sm *sm, char *buf, size_t buflen,
482 char *pos = buf, *end = buf + buflen;
485 if (sm->preauth_eapol) {
486 ret = os_snprintf(pos, end - pos, "Pre-authentication "
487 "EAPOL state machines:\n");
488 if (ret < 0 || ret >= end - pos)
491 res = eapol_sm_get_status(sm->preauth_eapol,
492 pos, end - pos, verbose);
499 #endif /* CONFIG_CTRL_IFACE */
503 * rsn_preauth_in_progress - Verify whether pre-authentication is in progress
504 * @sm: Pointer to WPA state machine data from wpa_sm_init()
506 int rsn_preauth_in_progress(struct wpa_sm *sm)
508 return sm->preauth_eapol != NULL;
511 #endif /* IEEE8021X_EAPOL and !CONFIG_NO_WPA2 */