Outline ![]()
Files ![]()
loading...
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
/*
* WPA Supplicant - RSN PMKSA cache
* Copyright (c) 2004-2009, 2011-2015, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include "common.h"
#include "eloop.h"
#include "rsn_supp/wpa.h"
#include "rsn_supp/wpa_i.h"
#include "common/eapol_common.h"
#include "common/ieee802_11_defs.h"
#include "pmksa_cache.h"
#ifdef IEEE8021X_EAPOL
static const int pmksa_cache_max_entries = 10;
static const int dot11RSNAConfigPMKLifetime = 8640000; // 100 days = 3600 x 24 x 100 Seconds
static const int dot11RSNAConfigPMKReauthThreshold = 70;
struct rsn_pmksa_cache {
struct rsn_pmksa_cache_entry *pmksa; /* PMKSA cache */
int pmksa_count; /* number of entries in PMKSA cache */
struct wpa_sm *sm; /* TODO: get rid of this reference(?) */
void (*free_cb)(struct rsn_pmksa_cache_entry *entry, void *ctx,
enum pmksa_free_reason reason);
void *ctx;
};
static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa);
static void _pmksa_cache_free_entry(struct rsn_pmksa_cache_entry *entry)
{
bin_clear_free(entry, sizeof(*entry));
}
static void pmksa_cache_free_entry(struct rsn_pmksa_cache *pmksa,
struct rsn_pmksa_cache_entry *entry,
enum pmksa_free_reason reason)
{
pmksa->pmksa_count--;
pmksa->free_cb(entry, pmksa->ctx, reason);
_pmksa_cache_free_entry(entry);
}
static void pmksa_cache_expire(void *eloop_ctx, void *user_data)
{
struct rsn_pmksa_cache *pmksa = eloop_ctx;
struct os_reltime now;
os_get_reltime(&now);
while (pmksa->pmksa && pmksa->pmksa->expiration <= now.sec) {
struct rsn_pmksa_cache_entry *entry = pmksa->pmksa;
pmksa->pmksa = entry->next;
wpa_printf(MSG_DEBUG, "RSN: expired PMKSA cache entry for "
MACSTR, MAC2STR(entry->aa));
pmksa_cache_free_entry(pmksa, entry, PMKSA_EXPIRE);
}
pmksa_cache_set_expiration(pmksa);
}
static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa)
{
int sec;
struct os_reltime now;
eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL);
if (pmksa->pmksa == NULL)
return;
os_get_reltime(&now);
sec = pmksa->pmksa->expiration - now.sec;
if (sec < 0)
sec = 0;
eloop_register_timeout(sec + 1, 0, pmksa_cache_expire, pmksa, NULL);
}
/**
* pmksa_cache_add - Add a PMKSA cache entry
* @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
* @pmk: The new pairwise master key
* @pmk_len: PMK length in bytes, usually PMK_LEN (32)
* @kck: Key confirmation key or %NULL if not yet derived
* @kck_len: KCK length in bytes
* @aa: Authenticator address
* @spa: Supplicant address
* @network_ctx: Network configuration context for this PMK
* @akmp: WPA_KEY_MGMT_* used in key derivation
* Returns: Pointer to the added PMKSA cache entry or %NULL on error
*
* This function create a PMKSA entry for a new PMK and adds it to the PMKSA
* cache. If an old entry is already in the cache for the same Authenticator,
* this entry will be replaced with the new entry. PMKID will be calculated
* based on the PMK and the driver interface is notified of the new PMKID.
*/
struct rsn_pmksa_cache_entry *
pmksa_cache_add(struct rsn_pmksa_cache *pmksa, const u8 *pmk, size_t pmk_len,
const u8 *pmkid, const u8 *kck, size_t kck_len,
const u8 *aa, const u8 *spa, void *network_ctx, int akmp)
{
struct rsn_pmksa_cache_entry *entry;
struct os_reltime now;
if (pmk_len > PMK_LEN_MAX)
return NULL;
if (wpa_key_mgmt_suite_b(akmp) && !kck)
return NULL;
entry = os_zalloc(sizeof(*entry));
if (entry == NULL)
return NULL;
os_memcpy(entry->pmk, pmk, pmk_len);
entry->pmk_len = pmk_len;
if (pmkid)
os_memcpy(entry->pmkid, pmkid, PMKID_LEN);
else if (akmp == WPA_KEY_MGMT_IEEE8021X_SUITE_B_192)
rsn_pmkid_suite_b_192(kck, kck_len, aa, spa, entry->pmkid);
else if (wpa_key_mgmt_suite_b(akmp))
rsn_pmkid_suite_b(kck, kck_len, aa, spa, entry->pmkid);
else
rsn_pmkid(pmk, pmk_len, aa, spa, entry->pmkid, akmp);
os_get_reltime(&now);
entry->expiration = now.sec + dot11RSNAConfigPMKLifetime;
entry->reauth_time = now.sec + dot11RSNAConfigPMKLifetime *
dot11RSNAConfigPMKReauthThreshold / 100;
entry->akmp = akmp;
os_memcpy(entry->aa, aa, ETH_ALEN);
entry->network_ctx = network_ctx;
return pmksa_cache_add_entry(pmksa, entry);
}
struct rsn_pmksa_cache_entry *
pmksa_cache_add_entry(struct rsn_pmksa_cache *pmksa,
struct rsn_pmksa_cache_entry *entry)
{
struct rsn_pmksa_cache_entry *pos, *prev;
/* Replace an old entry for the same Authenticator (if found) with the
* new entry */
pos = pmksa->pmksa;
prev = NULL;
while (pos) {
if (os_memcmp(entry->aa, pos->aa, ETH_ALEN) == 0) {
if (pos->pmk_len == entry->pmk_len &&
os_memcmp_const(pos->pmk, entry->pmk, entry->pmk_len) == 0 &&
os_memcmp_const(pos->pmkid, entry->pmkid,
PMKID_LEN) == 0) {
wpa_printf(MSG_DEBUG, "WPA: reusing previous "
"PMKSA entry");
os_free(entry);
return pos;
}
if (prev == NULL)
pmksa->pmksa = pos->next;
else
prev->next = pos->next;
/*
* If OKC is used, there may be other PMKSA cache
* entries based on the same PMK. These needs to be
* flushed so that a new entry can be created based on
* the new PMK. Only clear other entries if they have a
* matching PMK and this PMK has been used successfully
* with the current AP, i.e., if opportunistic flag has
* been cleared in wpa_supplicant_key_neg_complete().
*/
wpa_printf(MSG_DEBUG, "RSN: Replace PMKSA entry for "
"the current AP and any PMKSA cache entry "
"that was based on the old PMK");
if (!pos->opportunistic)
pmksa_cache_flush(pmksa, entry->network_ctx, pos->pmk,
pos->pmk_len);
pmksa_cache_free_entry(pmksa, pos, PMKSA_REPLACE);
break;
}
prev = pos;
pos = pos->next;
}
if (pmksa->pmksa_count >= pmksa_cache_max_entries && pmksa->pmksa) {
/* Remove the oldest entry to make room for the new entry */
pos = pmksa->pmksa;
if (pos == pmksa->sm->cur_pmksa) {
/*
* Never remove the current PMKSA cache entry, since
* it's in use, and removing it triggers a needless
* deauthentication.
*/
pos = pos->next;
pmksa->pmksa->next = pos ? pos->next : NULL;
} else
pmksa->pmksa = pos->next;
if (pos) {
wpa_printf(MSG_DEBUG, "RSN: removed the oldest idle "
"PMKSA cache entry (for " MACSTR ") to "
"make room for new one",
MAC2STR(pos->aa));
pmksa_cache_free_entry(pmksa, pos, PMKSA_FREE);
}
}
/* Add the new entry; order by expiration time */
pos = pmksa->pmksa;
prev = NULL;
while (pos) {
if (pos->expiration > entry->expiration)
break;
prev = pos;
pos = pos->next;
}
if (prev == NULL) {
entry->next = pmksa->pmksa;
pmksa->pmksa = entry;
pmksa_cache_set_expiration(pmksa);
} else {
entry->next = prev->next;
prev->next = entry;
}
pmksa->pmksa_count++;
wpa_printf(MSG_DEBUG, "RSN: Added PMKSA cache entry for " MACSTR
" network_ctx=%p", MAC2STR(entry->aa), entry->network_ctx);
return entry;
}
/**
* pmksa_cache_flush - Flush PMKSA cache entries for a specific network
* @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
* @network_ctx: Network configuration context or %NULL to flush all entries
* @pmk: PMK to match for or %NYLL to match all PMKs
* @pmk_len: PMK length
*/
void pmksa_cache_flush(struct rsn_pmksa_cache *pmksa, void *network_ctx,
const u8 *pmk, size_t pmk_len)
{
struct rsn_pmksa_cache_entry *entry, *prev = NULL, *tmp;
int removed = 0;
entry = pmksa->pmksa;
while (entry) {
if ((entry->network_ctx == network_ctx ||
network_ctx == NULL) &&
(pmk == NULL ||
(pmk_len == entry->pmk_len &&
os_memcmp(pmk, entry->pmk, pmk_len) == 0))) {
wpa_printf(MSG_DEBUG, "RSN: Flush PMKSA cache entry "
"for " MACSTR, MAC2STR(entry->aa));
if (prev)
prev->next = entry->next;
else
pmksa->pmksa = entry->next;
tmp = entry;
entry = entry->next;
pmksa_cache_free_entry(pmksa, tmp, PMKSA_FREE);
removed++;
} else {
prev = entry;
entry = entry->next;
}
}
/*if (removed)
pmksa_cache_set_expiration(pmksa);*/
}
/**
* pmksa_cache_deinit - Free all entries in PMKSA cache
* @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
*/
void pmksa_cache_deinit(struct rsn_pmksa_cache *pmksa)
{
struct rsn_pmksa_cache_entry *entry, *prev;
if (pmksa == NULL)
return;
entry = pmksa->pmksa;
pmksa->pmksa = NULL;
while (entry) {
prev = entry;
entry = entry->next;
os_free(prev);
}
pmksa_cache_set_expiration(pmksa);
eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL);
os_free(pmksa);
}
/**
* pmksa_cache_get - Fetch a PMKSA cache entry
* @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
* @aa: Authenticator address or %NULL to match any
* @pmkid: PMKID or %NULL to match any
* @network_ctx: Network context or %NULL to match any
* Returns: Pointer to PMKSA cache entry or %NULL if no match was found
*/
struct rsn_pmksa_cache_entry * pmksa_cache_get(struct rsn_pmksa_cache *pmksa,
const u8 *aa, const u8 *pmkid,
const void *network_ctx)
{
struct rsn_pmksa_cache_entry *entry = pmksa->pmksa;
while (entry) {
if ((aa == NULL || os_memcmp(entry->aa, aa, ETH_ALEN) == 0) &&
(pmkid == NULL ||
os_memcmp(entry->pmkid, pmkid, PMKID_LEN) == 0) &&
(network_ctx == NULL || network_ctx == entry->network_ctx))
return entry;
entry = entry->next;
}
return NULL;
}
static struct rsn_pmksa_cache_entry *
pmksa_cache_clone_entry(struct rsn_pmksa_cache *pmksa,
const struct rsn_pmksa_cache_entry *old_entry,
const u8 *aa)
{
struct rsn_pmksa_cache_entry *new_entry;
new_entry = pmksa_cache_add(pmksa, old_entry->pmk, old_entry->pmk_len,
NULL, NULL, 0,
aa, pmksa->sm->own_addr,
old_entry->network_ctx, old_entry->akmp);
if (new_entry == NULL)
return NULL;
/* TODO: reorder entries based on expiration time? */
new_entry->expiration = old_entry->expiration;
new_entry->opportunistic = 1;
return new_entry;
}
/**
* pmksa_cache_get_opportunistic - Try to get an opportunistic PMKSA entry
* @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
* @network_ctx: Network configuration context
* @aa: Authenticator address for the new AP
* Returns: Pointer to a new PMKSA cache entry or %NULL if not available
*
* Try to create a new PMKSA cache entry opportunistically by guessing that the
* new AP is sharing the same PMK as another AP that has the same SSID and has
* already an entry in PMKSA cache.
*/
struct rsn_pmksa_cache_entry *
pmksa_cache_get_opportunistic(struct rsn_pmksa_cache *pmksa, void *network_ctx,
const u8 *aa)
{
struct rsn_pmksa_cache_entry *entry = pmksa->pmksa;
wpa_printf(MSG_DEBUG, "RSN: Consider " MACSTR " for OKC", MAC2STR(aa));
if (network_ctx == NULL)
return NULL;
while (entry) {
if (entry->network_ctx == network_ctx) {
entry = pmksa_cache_clone_entry(pmksa, entry, aa);
if (entry) {
wpa_printf(MSG_DEBUG, "RSN: added "
"opportunistic PMKSA cache entry "
"for " MACSTR, MAC2STR(aa));
}
return entry;
}
entry = entry->next;
}
return NULL;
}
/**
* pmksa_cache_get_current - Get the current used PMKSA entry
* @sm: Pointer to WPA state machine data from wpa_sm_init()
* Returns: Pointer to the current PMKSA cache entry or %NULL if not available
*/
struct rsn_pmksa_cache_entry * pmksa_cache_get_current(struct wpa_sm *sm)
{
if (sm == NULL)
return NULL;
return sm->cur_pmksa;
}
/**
* pmksa_cache_clear_current - Clear the current PMKSA entry selection
* @sm: Pointer to WPA state machine data from wpa_sm_init()
*/
void pmksa_cache_clear_current(struct wpa_sm *sm)
{
if (sm == NULL)
return;
sm->cur_pmksa = NULL;
}
/**
* pmksa_cache_set_current - Set the current PMKSA entry selection
* @sm: Pointer to WPA state machine data from wpa_sm_init()
* @pmkid: PMKID for selecting PMKSA or %NULL if not used
* @bssid: BSSID for PMKSA or %NULL if not used
* @network_ctx: Network configuration context
* @try_opportunistic: Whether to allow opportunistic PMKSA caching
* Returns: 0 if PMKSA was found or -1 if no matching entry was found
*/
int pmksa_cache_set_current(struct wpa_sm *sm, const u8 *pmkid,
const u8 *bssid, void *network_ctx,
int try_opportunistic)
{
struct rsn_pmksa_cache *pmksa = sm->pmksa;
wpa_printf(MSG_DEBUG, "RSN: PMKSA cache search - network_ctx=%p "
"try_opportunistic=%d", network_ctx, try_opportunistic);
if (pmkid)
wpa_hexdump(MSG_DEBUG, "RSN: Search for PMKID",
pmkid, PMKID_LEN);
if (bssid)
wpa_printf(MSG_DEBUG, "RSN: Search for BSSID " MACSTR,
MAC2STR(bssid));
sm->cur_pmksa = NULL;
if (pmkid)
sm->cur_pmksa = pmksa_cache_get(pmksa, NULL, pmkid,
network_ctx);
if (sm->cur_pmksa == NULL && bssid)
sm->cur_pmksa = pmksa_cache_get(pmksa, bssid, NULL,
network_ctx);
if (sm->cur_pmksa == NULL && try_opportunistic && bssid)
sm->cur_pmksa = pmksa_cache_get_opportunistic(pmksa,
network_ctx,
bssid);
if (sm->cur_pmksa) {
wpa_hexdump(MSG_DEBUG, "RSN: PMKSA cache entry found - PMKID",
sm->cur_pmksa->pmkid, PMKID_LEN);
return 0;
}
wpa_printf(MSG_DEBUG, "RSN: No PMKSA cache entry found");
return -1;
}
/**
* pmksa_cache_list - Dump text list of entries in PMKSA cache
* @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
* @buf: Buffer for the list
* @len: Length of the buffer
* Returns: number of bytes written to buffer
*
* This function is used to generate a text format representation of the
* current PMKSA cache contents for the ctrl_iface PMKSA command.
*/
int pmksa_cache_list(struct rsn_pmksa_cache *pmksa, char *buf, size_t len)
{
int i, ret;
char *pos = buf;
struct rsn_pmksa_cache_entry *entry;
struct os_reltime now;
ret = os_snprintf(pos, buf + len - pos,
"Index / AA / PMKID / expiration (in seconds) / "
"opportunistic\n");
if (os_snprintf_error(buf + len - pos, ret))
return pos - buf;
pos += ret;
i = 0;
entry = pmksa->pmksa;
os_get_reltime(&now);
while (entry) {
i++;
ret = os_snprintf(pos, buf + len - pos, "%d " MACSTR " ",
i, MAC2STR(entry->aa));
if (os_snprintf_error(buf + len - pos, ret))
return pos - buf;
pos += ret;
pos += wpa_snprintf_hex(pos, buf + len - pos, entry->pmkid,
PMKID_LEN);
ret = os_snprintf(pos, buf + len - pos, " %d %d\n",
(int) (entry->expiration - now.sec),
entry->opportunistic);
if (os_snprintf_error(buf + len - pos, ret))
return pos - buf;
pos += ret;
entry = entry->next;
}
return pos - buf;
}
/**
* pmksa_cache_init - Initialize PMKSA cache
* @free_cb: Callback function to be called when a PMKSA cache entry is freed
* @ctx: Context pointer for free_cb function
* @sm: Pointer to WPA state machine data from wpa_sm_init()
* Returns: Pointer to PMKSA cache data or %NULL on failure
*/
struct rsn_pmksa_cache *
pmksa_cache_init(void (*free_cb)(struct rsn_pmksa_cache_entry *entry,
void *ctx, enum pmksa_free_reason reason),
void *ctx, struct wpa_sm *sm)
{
struct rsn_pmksa_cache *pmksa;
pmksa = os_zalloc(sizeof(*pmksa));
if (pmksa) {
pmksa->free_cb = free_cb;
pmksa->ctx = ctx;
pmksa->sm = sm;
pmksa->pmksa_count = 0;
pmksa->pmksa = NULL;
}
return pmksa;
}
#endif /* IEEE8021X_EAPOL */
Details ![]()
Show: from Types: Columns: ![]( "Show Project Names")
![]( "Show Locations")
![]( "Show Referring Symbols")
![]( "Show Scope")
This file uses the notable symbols shown below. Click anywhere in the file to view more details.