pmksa_cache_auth.c revision d5e4923d04122f81300fa68fb07d64ede28fd44d
1/* 2 * hostapd - PMKSA cache for IEEE 802.11i RSN 3 * Copyright (c) 2004-2008, 2012, Jouni Malinen <j@w1.fi> 4 * 5 * This software may be distributed under the terms of the BSD license. 6 * See README for more details. 7 */ 8 9#include "utils/includes.h" 10 11#include "utils/common.h" 12#include "utils/eloop.h" 13#include "eapol_auth/eapol_auth_sm.h" 14#include "eapol_auth/eapol_auth_sm_i.h" 15#include "sta_info.h" 16#include "ap_config.h" 17#include "pmksa_cache_auth.h" 18 19 20static const int pmksa_cache_max_entries = 1024; 21static const int dot11RSNAConfigPMKLifetime = 43200; 22 23struct rsn_pmksa_cache { 24#define PMKID_HASH_SIZE 128 25#define PMKID_HASH(pmkid) (unsigned int) ((pmkid)[0] & 0x7f) 26 struct rsn_pmksa_cache_entry *pmkid[PMKID_HASH_SIZE]; 27 struct rsn_pmksa_cache_entry *pmksa; 28 int pmksa_count; 29 30 void (*free_cb)(struct rsn_pmksa_cache_entry *entry, void *ctx); 31 void *ctx; 32}; 33 34 35static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa); 36 37 38static void _pmksa_cache_free_entry(struct rsn_pmksa_cache_entry *entry) 39{ 40 if (entry == NULL) 41 return; 42 os_free(entry->identity); 43 wpabuf_free(entry->cui); 44#ifndef CONFIG_NO_RADIUS 45 radius_free_class(&entry->radius_class); 46#endif /* CONFIG_NO_RADIUS */ 47 os_free(entry); 48} 49 50 51static void pmksa_cache_free_entry(struct rsn_pmksa_cache *pmksa, 52 struct rsn_pmksa_cache_entry *entry) 53{ 54 struct rsn_pmksa_cache_entry *pos, *prev; 55 56 pmksa->pmksa_count--; 57 pmksa->free_cb(entry, pmksa->ctx); 58 pos = pmksa->pmkid[PMKID_HASH(entry->pmkid)]; 59 prev = NULL; 60 while (pos) { 61 if (pos == entry) { 62 if (prev != NULL) { 63 prev->hnext = pos->hnext; 64 } else { 65 pmksa->pmkid[PMKID_HASH(entry->pmkid)] = 66 pos->hnext; 67 } 68 break; 69 } 70 prev = pos; 71 pos = pos->hnext; 72 } 73 74 pos = pmksa->pmksa; 75 prev = NULL; 76 while (pos) { 77 if (pos == entry) { 78 if (prev != NULL) 79 prev->next = pos->next; 80 else 81 pmksa->pmksa = pos->next; 82 break; 83 } 84 prev = pos; 85 pos = pos->next; 86 } 87 _pmksa_cache_free_entry(entry); 88} 89 90 91static void pmksa_cache_expire(void *eloop_ctx, void *timeout_ctx) 92{ 93 struct rsn_pmksa_cache *pmksa = eloop_ctx; 94 struct os_time now; 95 96 os_get_time(&now); 97 while (pmksa->pmksa && pmksa->pmksa->expiration <= now.sec) { 98 wpa_printf(MSG_DEBUG, "RSN: expired PMKSA cache entry for " 99 MACSTR, MAC2STR(pmksa->pmksa->spa)); 100 pmksa_cache_free_entry(pmksa, pmksa->pmksa); 101 } 102 103 pmksa_cache_set_expiration(pmksa); 104} 105 106 107static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa) 108{ 109 int sec; 110 struct os_time now; 111 112 eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL); 113 if (pmksa->pmksa == NULL) 114 return; 115 os_get_time(&now); 116 sec = pmksa->pmksa->expiration - now.sec; 117 if (sec < 0) 118 sec = 0; 119 eloop_register_timeout(sec + 1, 0, pmksa_cache_expire, pmksa, NULL); 120} 121 122 123static void pmksa_cache_from_eapol_data(struct rsn_pmksa_cache_entry *entry, 124 struct eapol_state_machine *eapol) 125{ 126 if (eapol == NULL) 127 return; 128 129 if (eapol->identity) { 130 entry->identity = os_malloc(eapol->identity_len); 131 if (entry->identity) { 132 entry->identity_len = eapol->identity_len; 133 os_memcpy(entry->identity, eapol->identity, 134 eapol->identity_len); 135 } 136 } 137 138 if (eapol->radius_cui) 139 entry->cui = wpabuf_dup(eapol->radius_cui); 140 141#ifndef CONFIG_NO_RADIUS 142 radius_copy_class(&entry->radius_class, &eapol->radius_class); 143#endif /* CONFIG_NO_RADIUS */ 144 145 entry->eap_type_authsrv = eapol->eap_type_authsrv; 146 entry->vlan_id = ((struct sta_info *) eapol->sta)->vlan_id; 147} 148 149 150void pmksa_cache_to_eapol_data(struct rsn_pmksa_cache_entry *entry, 151 struct eapol_state_machine *eapol) 152{ 153 if (entry == NULL || eapol == NULL) 154 return; 155 156 if (entry->identity) { 157 os_free(eapol->identity); 158 eapol->identity = os_malloc(entry->identity_len); 159 if (eapol->identity) { 160 eapol->identity_len = entry->identity_len; 161 os_memcpy(eapol->identity, entry->identity, 162 entry->identity_len); 163 } 164 wpa_hexdump_ascii(MSG_DEBUG, "STA identity from PMKSA", 165 eapol->identity, eapol->identity_len); 166 } 167 168 if (entry->cui) { 169 wpabuf_free(eapol->radius_cui); 170 eapol->radius_cui = wpabuf_dup(entry->cui); 171 } 172 173#ifndef CONFIG_NO_RADIUS 174 radius_free_class(&eapol->radius_class); 175 radius_copy_class(&eapol->radius_class, &entry->radius_class); 176#endif /* CONFIG_NO_RADIUS */ 177 if (eapol->radius_class.attr) { 178 wpa_printf(MSG_DEBUG, "Copied %lu Class attribute(s) from " 179 "PMKSA", (unsigned long) eapol->radius_class.count); 180 } 181 182 eapol->eap_type_authsrv = entry->eap_type_authsrv; 183 ((struct sta_info *) eapol->sta)->vlan_id = entry->vlan_id; 184} 185 186 187static void pmksa_cache_link_entry(struct rsn_pmksa_cache *pmksa, 188 struct rsn_pmksa_cache_entry *entry) 189{ 190 struct rsn_pmksa_cache_entry *pos, *prev; 191 192 /* Add the new entry; order by expiration time */ 193 pos = pmksa->pmksa; 194 prev = NULL; 195 while (pos) { 196 if (pos->expiration > entry->expiration) 197 break; 198 prev = pos; 199 pos = pos->next; 200 } 201 if (prev == NULL) { 202 entry->next = pmksa->pmksa; 203 pmksa->pmksa = entry; 204 } else { 205 entry->next = prev->next; 206 prev->next = entry; 207 } 208 entry->hnext = pmksa->pmkid[PMKID_HASH(entry->pmkid)]; 209 pmksa->pmkid[PMKID_HASH(entry->pmkid)] = entry; 210 211 pmksa->pmksa_count++; 212 wpa_printf(MSG_DEBUG, "RSN: added PMKSA cache entry for " MACSTR, 213 MAC2STR(entry->spa)); 214 wpa_hexdump(MSG_DEBUG, "RSN: added PMKID", entry->pmkid, PMKID_LEN); 215} 216 217 218/** 219 * pmksa_cache_auth_add - Add a PMKSA cache entry 220 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init() 221 * @pmk: The new pairwise master key 222 * @pmk_len: PMK length in bytes, usually PMK_LEN (32) 223 * @aa: Authenticator address 224 * @spa: Supplicant address 225 * @session_timeout: Session timeout 226 * @eapol: Pointer to EAPOL state machine data 227 * @akmp: WPA_KEY_MGMT_* used in key derivation 228 * Returns: Pointer to the added PMKSA cache entry or %NULL on error 229 * 230 * This function create a PMKSA entry for a new PMK and adds it to the PMKSA 231 * cache. If an old entry is already in the cache for the same Supplicant, 232 * this entry will be replaced with the new entry. PMKID will be calculated 233 * based on the PMK. 234 */ 235struct rsn_pmksa_cache_entry * 236pmksa_cache_auth_add(struct rsn_pmksa_cache *pmksa, 237 const u8 *pmk, size_t pmk_len, 238 const u8 *aa, const u8 *spa, int session_timeout, 239 struct eapol_state_machine *eapol, int akmp) 240{ 241 struct rsn_pmksa_cache_entry *entry, *pos; 242 struct os_time now; 243 244 if (pmk_len > PMK_LEN) 245 return NULL; 246 247 entry = os_zalloc(sizeof(*entry)); 248 if (entry == NULL) 249 return NULL; 250 os_memcpy(entry->pmk, pmk, pmk_len); 251 entry->pmk_len = pmk_len; 252 rsn_pmkid(pmk, pmk_len, aa, spa, entry->pmkid, 253 wpa_key_mgmt_sha256(akmp)); 254 os_get_time(&now); 255 entry->expiration = now.sec; 256 if (session_timeout > 0) 257 entry->expiration += session_timeout; 258 else 259 entry->expiration += dot11RSNAConfigPMKLifetime; 260 entry->akmp = akmp; 261 os_memcpy(entry->spa, spa, ETH_ALEN); 262 pmksa_cache_from_eapol_data(entry, eapol); 263 264 /* Replace an old entry for the same STA (if found) with the new entry 265 */ 266 pos = pmksa_cache_auth_get(pmksa, spa, NULL); 267 if (pos) 268 pmksa_cache_free_entry(pmksa, pos); 269 270 if (pmksa->pmksa_count >= pmksa_cache_max_entries && pmksa->pmksa) { 271 /* Remove the oldest entry to make room for the new entry */ 272 wpa_printf(MSG_DEBUG, "RSN: removed the oldest PMKSA cache " 273 "entry (for " MACSTR ") to make room for new one", 274 MAC2STR(pmksa->pmksa->spa)); 275 pmksa_cache_free_entry(pmksa, pmksa->pmksa); 276 } 277 278 pmksa_cache_link_entry(pmksa, entry); 279 280 return entry; 281} 282 283 284struct rsn_pmksa_cache_entry * 285pmksa_cache_add_okc(struct rsn_pmksa_cache *pmksa, 286 const struct rsn_pmksa_cache_entry *old_entry, 287 const u8 *aa, const u8 *pmkid) 288{ 289 struct rsn_pmksa_cache_entry *entry; 290 291 entry = os_zalloc(sizeof(*entry)); 292 if (entry == NULL) 293 return NULL; 294 os_memcpy(entry->pmkid, pmkid, PMKID_LEN); 295 os_memcpy(entry->pmk, old_entry->pmk, old_entry->pmk_len); 296 entry->pmk_len = old_entry->pmk_len; 297 entry->expiration = old_entry->expiration; 298 entry->akmp = old_entry->akmp; 299 os_memcpy(entry->spa, old_entry->spa, ETH_ALEN); 300 entry->opportunistic = 1; 301 if (old_entry->identity) { 302 entry->identity = os_malloc(old_entry->identity_len); 303 if (entry->identity) { 304 entry->identity_len = old_entry->identity_len; 305 os_memcpy(entry->identity, old_entry->identity, 306 old_entry->identity_len); 307 } 308 } 309 if (old_entry->cui) 310 entry->cui = wpabuf_dup(old_entry->cui); 311#ifndef CONFIG_NO_RADIUS 312 radius_copy_class(&entry->radius_class, &old_entry->radius_class); 313#endif /* CONFIG_NO_RADIUS */ 314 entry->eap_type_authsrv = old_entry->eap_type_authsrv; 315 entry->vlan_id = old_entry->vlan_id; 316 entry->opportunistic = 1; 317 318 pmksa_cache_link_entry(pmksa, entry); 319 320 return entry; 321} 322 323 324/** 325 * pmksa_cache_auth_deinit - Free all entries in PMKSA cache 326 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init() 327 */ 328void pmksa_cache_auth_deinit(struct rsn_pmksa_cache *pmksa) 329{ 330 struct rsn_pmksa_cache_entry *entry, *prev; 331 int i; 332 333 if (pmksa == NULL) 334 return; 335 336 entry = pmksa->pmksa; 337 while (entry) { 338 prev = entry; 339 entry = entry->next; 340 _pmksa_cache_free_entry(prev); 341 } 342 eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL); 343 for (i = 0; i < PMKID_HASH_SIZE; i++) 344 pmksa->pmkid[i] = NULL; 345 os_free(pmksa); 346} 347 348 349/** 350 * pmksa_cache_auth_get - Fetch a PMKSA cache entry 351 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init() 352 * @spa: Supplicant address or %NULL to match any 353 * @pmkid: PMKID or %NULL to match any 354 * Returns: Pointer to PMKSA cache entry or %NULL if no match was found 355 */ 356struct rsn_pmksa_cache_entry * 357pmksa_cache_auth_get(struct rsn_pmksa_cache *pmksa, 358 const u8 *spa, const u8 *pmkid) 359{ 360 struct rsn_pmksa_cache_entry *entry; 361 362 if (pmkid) 363 entry = pmksa->pmkid[PMKID_HASH(pmkid)]; 364 else 365 entry = pmksa->pmksa; 366 while (entry) { 367 if ((spa == NULL || 368 os_memcmp(entry->spa, spa, ETH_ALEN) == 0) && 369 (pmkid == NULL || 370 os_memcmp(entry->pmkid, pmkid, PMKID_LEN) == 0)) 371 return entry; 372 entry = pmkid ? entry->hnext : entry->next; 373 } 374 return NULL; 375} 376 377 378/** 379 * pmksa_cache_get_okc - Fetch a PMKSA cache entry using OKC 380 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init() 381 * @aa: Authenticator address 382 * @spa: Supplicant address 383 * @pmkid: PMKID 384 * Returns: Pointer to PMKSA cache entry or %NULL if no match was found 385 * 386 * Use opportunistic key caching (OKC) to find a PMK for a supplicant. 387 */ 388struct rsn_pmksa_cache_entry * pmksa_cache_get_okc( 389 struct rsn_pmksa_cache *pmksa, const u8 *aa, const u8 *spa, 390 const u8 *pmkid) 391{ 392 struct rsn_pmksa_cache_entry *entry; 393 u8 new_pmkid[PMKID_LEN]; 394 395 entry = pmksa->pmksa; 396 while (entry) { 397 if (os_memcmp(entry->spa, spa, ETH_ALEN) != 0) 398 continue; 399 rsn_pmkid(entry->pmk, entry->pmk_len, aa, spa, new_pmkid, 400 wpa_key_mgmt_sha256(entry->akmp)); 401 if (os_memcmp(new_pmkid, pmkid, PMKID_LEN) == 0) 402 return entry; 403 entry = entry->next; 404 } 405 return NULL; 406} 407 408 409/** 410 * pmksa_cache_auth_init - Initialize PMKSA cache 411 * @free_cb: Callback function to be called when a PMKSA cache entry is freed 412 * @ctx: Context pointer for free_cb function 413 * Returns: Pointer to PMKSA cache data or %NULL on failure 414 */ 415struct rsn_pmksa_cache * 416pmksa_cache_auth_init(void (*free_cb)(struct rsn_pmksa_cache_entry *entry, 417 void *ctx), void *ctx) 418{ 419 struct rsn_pmksa_cache *pmksa; 420 421 pmksa = os_zalloc(sizeof(*pmksa)); 422 if (pmksa) { 423 pmksa->free_cb = free_cb; 424 pmksa->ctx = ctx; 425 } 426 427 return pmksa; 428} 429