aboutsummaryrefslogtreecommitdiffstats
path: root/src/rsn_supp/pmksa_cache.c
diff options
context:
space:
mode:
authorJouni Malinen <j@w1.fi>2008-02-28 01:34:43 (GMT)
committerJouni Malinen <jm@jm.kir.nu>2008-02-28 01:34:43 (GMT)
commit6fc6879bd55a394f807cbbe927df736c190cb8ab (patch)
treecdf50da0c58f21510a808d53502a060d911ff243 /src/rsn_supp/pmksa_cache.c
downloadhostap-06-6fc6879bd55a394f807cbbe927df736c190cb8ab.zip
hostap-06-6fc6879bd55a394f807cbbe927df736c190cb8ab.tar.gz
hostap-06-6fc6879bd55a394f807cbbe927df736c190cb8ab.tar.bz2
Re-initialize hostapd/wpa_supplicant git repository based on 0.6.3 release
Diffstat (limited to 'src/rsn_supp/pmksa_cache.c')
-rw-r--r--src/rsn_supp/pmksa_cache.c502
1 files changed, 502 insertions, 0 deletions
diff --git a/src/rsn_supp/pmksa_cache.c b/src/rsn_supp/pmksa_cache.c
new file mode 100644
index 0000000..2a5bb5a
--- /dev/null
+++ b/src/rsn_supp/pmksa_cache.c
@@ -0,0 +1,502 @@
+/*
+ * WPA Supplicant - RSN PMKSA cache
+ * Copyright (c) 2004-2006, Jouni Malinen <j@w1.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#include "includes.h"
+
+#include "common.h"
+#include "wpa.h"
+#include "eloop.h"
+#include "sha1.h"
+#include "wpa_i.h"
+#include "eapol_supp/eapol_supp_sm.h"
+#include "pmksa_cache.h"
+
+#if defined(IEEE8021X_EAPOL) && !defined(CONFIG_NO_WPA2)
+
+static const int pmksa_cache_max_entries = 32;
+
+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,
+ int replace);
+ void *ctx;
+};
+
+
+/**
+ * rsn_pmkid - Calculate PMK identifier
+ * @pmk: Pairwise master key
+ * @pmk_len: Length of pmk in bytes
+ * @aa: Authenticator address
+ * @spa: Supplicant address
+ *
+ * IEEE Std 802.11i-2004 - 8.5.1.2 Pairwise key hierarchy
+ * PMKID = HMAC-SHA1-128(PMK, "PMK Name" || AA || SPA)
+ */
+void rsn_pmkid(const u8 *pmk, size_t pmk_len, const u8 *aa, const u8 *spa,
+ u8 *pmkid)
+{
+ char *title = "PMK Name";
+ const u8 *addr[3];
+ const size_t len[3] = { 8, ETH_ALEN, ETH_ALEN };
+ unsigned char hash[SHA1_MAC_LEN];
+
+ addr[0] = (u8 *) title;
+ addr[1] = aa;
+ addr[2] = spa;
+
+ hmac_sha1_vector(pmk, pmk_len, 3, addr, len, hash);
+ os_memcpy(pmkid, hash, PMKID_LEN);
+}
+
+
+static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa);
+
+
+static void _pmksa_cache_free_entry(struct rsn_pmksa_cache_entry *entry)
+{
+ os_free(entry);
+}
+
+
+static void pmksa_cache_free_entry(struct rsn_pmksa_cache *pmksa,
+ struct rsn_pmksa_cache_entry *entry,
+ int replace)
+{
+ pmksa->pmksa_count--;
+ pmksa->free_cb(entry, pmksa->ctx, replace);
+ _pmksa_cache_free_entry(entry);
+}
+
+
+static void pmksa_cache_expire(void *eloop_ctx, void *timeout_ctx)
+{
+ struct rsn_pmksa_cache *pmksa = eloop_ctx;
+ struct os_time now;
+
+ os_get_time(&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, 0);
+ }
+
+ pmksa_cache_set_expiration(pmksa);
+}
+
+
+static void pmksa_cache_reauth(void *eloop_ctx, void *timeout_ctx)
+{
+ struct rsn_pmksa_cache *pmksa = eloop_ctx;
+ pmksa->sm->cur_pmksa = NULL;
+ eapol_sm_request_reauth(pmksa->sm->eapol);
+}
+
+
+static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa)
+{
+ int sec;
+ struct rsn_pmksa_cache_entry *entry;
+ struct os_time now;
+
+ eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL);
+ eloop_cancel_timeout(pmksa_cache_reauth, pmksa, NULL);
+ if (pmksa->pmksa == NULL)
+ return;
+ os_get_time(&now);
+ sec = pmksa->pmksa->expiration - now.sec;
+ if (sec < 0)
+ sec = 0;
+ eloop_register_timeout(sec + 1, 0, pmksa_cache_expire, pmksa, NULL);
+
+ entry = pmksa->sm->cur_pmksa ? pmksa->sm->cur_pmksa :
+ pmksa_cache_get(pmksa, pmksa->sm->bssid, NULL);
+ if (entry) {
+ sec = pmksa->pmksa->reauth_time - now.sec;
+ if (sec < 0)
+ sec = 0;
+ eloop_register_timeout(sec, 0, pmksa_cache_reauth, 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)
+ * @aa: Authenticator address
+ * @spa: Supplicant address
+ * @network_ctx: Network configuration context for this PMK
+ * 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 *aa, const u8 *spa, void *network_ctx)
+{
+ struct rsn_pmksa_cache_entry *entry, *pos, *prev;
+ struct os_time now;
+
+ if (pmksa->sm->proto != WPA_PROTO_RSN || pmk_len > PMK_LEN)
+ return NULL;
+
+ entry = os_zalloc(sizeof(*entry));
+ if (entry == NULL)
+ return NULL;
+ os_memcpy(entry->pmk, pmk, pmk_len);
+ entry->pmk_len = pmk_len;
+ rsn_pmkid(pmk, pmk_len, aa, spa, entry->pmkid);
+ os_get_time(&now);
+ entry->expiration = now.sec + pmksa->sm->dot11RSNAConfigPMKLifetime;
+ entry->reauth_time = now.sec + pmksa->sm->dot11RSNAConfigPMKLifetime *
+ pmksa->sm->dot11RSNAConfigPMKReauthThreshold / 100;
+ entry->akmp = WPA_KEY_MGMT_IEEE8021X;
+ os_memcpy(entry->aa, aa, ETH_ALEN);
+ entry->network_ctx = network_ctx;
+
+ /* Replace an old entry for the same Authenticator (if found) with the
+ * new entry */
+ pos = pmksa->pmksa;
+ prev = NULL;
+ while (pos) {
+ if (os_memcmp(aa, pos->aa, ETH_ALEN) == 0) {
+ if (pos->pmk_len == pmk_len &&
+ os_memcmp(pos->pmk, pmk, pmk_len) == 0 &&
+ os_memcmp(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 (pos == pmksa->sm->cur_pmksa) {
+ /* We are about to replace the current PMKSA
+ * cache entry. This happens when the PMKSA
+ * caching attempt fails, so we don't want to
+ * force pmksa_cache_free_entry() to disconnect
+ * at this point. Let's just make sure the old
+ * PMKSA cache entry will not be used in the
+ * future.
+ */
+ wpa_printf(MSG_DEBUG, "RSN: replacing current "
+ "PMKSA entry");
+ pmksa->sm->cur_pmksa = NULL;
+ }
+ wpa_printf(MSG_DEBUG, "RSN: Replace PMKSA entry for "
+ "the current AP");
+ pmksa_cache_free_entry(pmksa, pos, 1);
+ 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;
+ pmksa->pmksa = pos->next;
+ wpa_printf(MSG_DEBUG, "RSN: removed the oldest PMKSA cache "
+ "entry (for " MACSTR ") to make room for new one",
+ MAC2STR(pos->aa));
+ wpa_sm_remove_pmkid(pmksa->sm, pos->aa, pos->pmkid);
+ pmksa_cache_free_entry(pmksa, pos, 0);
+ }
+
+ /* 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,
+ MAC2STR(entry->aa));
+ wpa_sm_add_pmkid(pmksa->sm, entry->aa, entry->pmkid);
+
+ return entry;
+}
+
+
+/**
+ * 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);
+ 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
+ * 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)
+{
+ 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))
+ return entry;
+ entry = entry->next;
+ }
+ return NULL;
+}
+
+
+/**
+ * pmksa_cache_notify_reconfig - Reconfiguration notification for PMKSA cache
+ * @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
+ *
+ * Clear references to old data structures when wpa_supplicant is reconfigured.
+ */
+void pmksa_cache_notify_reconfig(struct rsn_pmksa_cache *pmksa)
+{
+ struct rsn_pmksa_cache_entry *entry = pmksa->pmksa;
+ while (entry) {
+ entry->network_ctx = NULL;
+ entry = entry->next;
+ }
+}
+
+
+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,
+ aa, pmksa->sm->own_addr,
+ old_entry->network_ctx);
+ 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;
+
+ 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;
+ sm->cur_pmksa = NULL;
+ if (pmkid)
+ sm->cur_pmksa = pmksa_cache_get(pmksa, NULL, pmkid);
+ if (sm->cur_pmksa == NULL && bssid)
+ sm->cur_pmksa = pmksa_cache_get(pmksa, bssid, NULL);
+ 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: PMKID",
+ sm->cur_pmksa->pmkid, PMKID_LEN);
+ return 0;
+ }
+ return -1;
+}
+
+
+/**
+ * pmksa_cache_list - Dump text list of entries in PMKSA cache
+ * @sm: Pointer to WPA state machine data from wpa_sm_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 wpa_sm *sm, char *buf, size_t len)
+{
+ int i, ret;
+ char *pos = buf;
+ struct rsn_pmksa_cache_entry *entry;
+ struct os_time now;
+
+ os_get_time(&now);
+ ret = os_snprintf(pos, buf + len - pos,
+ "Index / AA / PMKID / expiration (in seconds) / "
+ "opportunistic\n");
+ if (ret < 0 || ret >= buf + len - pos)
+ return pos - buf;
+ pos += ret;
+ i = 0;
+ entry = sm->pmksa->pmksa;
+ while (entry) {
+ i++;
+ ret = os_snprintf(pos, buf + len - pos, "%d " MACSTR " ",
+ i, MAC2STR(entry->aa));
+ if (ret < 0 || ret >= buf + len - pos)
+ 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 (ret < 0 || ret >= buf + len - pos)
+ 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, int replace),
+ 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;
+ }
+
+ return pmksa;
+}
+
+#endif /* IEEE8021X_EAPOL and !CONFIG_NO_WPA2 */