PASN: Deauthenticate on PTKSA cache entry expiration

Add an option for an alternative processing of PTKSA life time expiry.

Register a callback in wpa_supplicant to handle the life time expiry of
the keys in PTKSA cache. Send PASN deauthentication when a PTKSA cache
entry expires.

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>

src/ap/ieee802_11.c

@@ -3503,7 +3503,7 @@ static void handle_auth_pasn_3(struct hostapd_data *hapd, struct sta_info *sta,
 		   "PASN: Success handling transaction == 3. Store PTK");
 
 	ptksa_cache_add(hapd->ptksa, hapd->own_addr, sta->addr,
-			sta->pasn->cipher, 43200, &sta->pasn->ptk);
+			sta->pasn->cipher, 43200, &sta->pasn->ptk, NULL, NULL);
 fail:
 	ap_free_sta(hapd, sta);
 }

src/ap/wpa_auth_glue.c

@@ -935,7 +935,7 @@ static void hostapd_store_ptksa(void *ctx, const u8 *addr,int cipher,
 	struct hostapd_data *hapd = ctx;
 
 	ptksa_cache_add(hapd->ptksa, hapd->own_addr, addr, cipher, life_time,
-			ptk);
+			ptk, NULL, NULL);
 }
 
 

src/common/ptksa_cache.c

@@ -51,6 +51,9 @@ static void ptksa_cache_expire(void *eloop_ctx, void *timeout_ctx)
 		wpa_printf(MSG_DEBUG, "Expired PTKSA cache entry for " MACSTR,
 			   MAC2STR(e->addr));
 
+		if (e->cb && e->ctx)
+			e->cb(e);
+		else
 			ptksa_cache_free_entry(ptksa, e);
 	}
 
@@ -259,6 +262,8 @@ void ptksa_cache_flush(struct ptksa_cache *ptksa, const u8 *addr, u32 cipher)
  * @cipher: The cipher used
  * @life_time: The PTK life time in seconds
  * @ptk: The PTK
+ * @life_time_expiry_cb: Callback for alternative expiration handling
+ * @ctx: Context pointer to save into e->ctx for the callback
  * Returns: Pointer to the added PTKSA cache entry or %NULL on error
  *
  * This function creates a PTKSA entry and adds it to the PTKSA cache.
@@ -269,7 +274,10 @@ struct ptksa_cache_entry * ptksa_cache_add(struct ptksa_cache *ptksa,
 					   const u8 *own_addr,
 					   const u8 *addr, u32 cipher,
 					   u32 life_time,
-					   const struct wpa_ptk *ptk)
+					   const struct wpa_ptk *ptk,
+					   void (*life_time_expiry_cb)
+					   (struct ptksa_cache_entry *e),
+					   void *ctx)
 {
 	struct ptksa_cache_entry *entry, *tmp, *tmp2 = NULL;
 	struct os_reltime now;
@@ -291,6 +299,9 @@ struct ptksa_cache_entry * ptksa_cache_add(struct ptksa_cache *ptksa,
 	dl_list_init(&entry->list);
 	os_memcpy(entry->addr, addr, ETH_ALEN);
 	entry->cipher = cipher;
+	entry->cb = life_time_expiry_cb;
+	entry->ctx = ctx;
+
 	if (own_addr)
 		os_memcpy(entry->own_addr, own_addr, ETH_ALEN);
 

src/common/ptksa_cache.h

@@ -24,6 +24,8 @@ struct ptksa_cache_entry {
 	u32 cipher;
 	u8 addr[ETH_ALEN];
 	u8 own_addr[ETH_ALEN];
+	void (*cb)(struct ptksa_cache_entry *e);
+	void *ctx;
 };
 
 #ifdef CONFIG_PTKSA_CACHE
@@ -39,7 +41,10 @@ struct ptksa_cache_entry * ptksa_cache_add(struct ptksa_cache *ptksa,
 					   const u8 *own_addr,
 					   const u8 *addr, u32 cipher,
 					   u32 life_time,
-					   const struct wpa_ptk *ptk);
+					   const struct wpa_ptk *ptk,
+					   void (*cb)
+					   (struct ptksa_cache_entry *e),
+					   void *ctx);
 void ptksa_cache_flush(struct ptksa_cache *ptksa, const u8 *addr, u32 cipher);
 
 #else /* CONFIG_PTKSA_CACHE */
@@ -67,7 +72,8 @@ static inline int ptksa_cache_list(struct ptksa_cache *ptksa,
 
 static inline struct ptksa_cache_entry *
 ptksa_cache_add(struct ptksa_cache *ptksa, const u8 *own_addr, const u8 *addr,
-		u32 cipher, u32 life_time, const struct wpa_ptk *ptk)
+		u32 cipher, u32 life_time, const struct wpa_ptk *ptk,
+		void (*cb)(struct ptksa_cache_entry *e), void *ctx)
 {
 	return NULL;
 }

wpa_supplicant/pasn_supplicant.c

@@ -1584,6 +1584,14 @@ static int wpas_pasn_immediate_retry(struct wpa_supplicant *wpa_s,
 }
 
 
+static void wpas_pasn_deauth_cb(struct ptksa_cache_entry *entry)
+{
+	struct wpa_supplicant *wpa_s = entry->ctx;
+
+	wpas_pasn_deauthenticate(wpa_s, entry->own_addr, entry->addr);
+}
+
+
 int wpas_pasn_auth_rx(struct wpa_supplicant *wpa_s,
 		      const struct ieee80211_mgmt *mgmt, size_t len)
 {
@@ -1825,7 +1833,9 @@ int wpas_pasn_auth_rx(struct wpa_supplicant *wpa_s,
 	wpa_printf(MSG_DEBUG, "PASN: Success sending last frame. Store PTK");
 
 	ptksa_cache_add(wpa_s->ptksa, pasn->own_addr, pasn->bssid,
-			pasn->cipher, dot11RSNAConfigPMKLifetime, &pasn->ptk);
+			pasn->cipher, dot11RSNAConfigPMKLifetime, &pasn->ptk,
+			wpa_s->pasn_params ? wpas_pasn_deauth_cb : NULL,
+			wpa_s->pasn_params ? wpa_s : NULL);
 
 	forced_memzero(&pasn->ptk, sizeof(pasn->ptk));
 

wpa_supplicant/wpas_glue.c

@@ -1379,7 +1379,7 @@ static void wpa_supplicant_store_ptk(void *ctx, u8 *addr, int cipher,
 	struct wpa_supplicant *wpa_s = ctx;
 
 	ptksa_cache_add(wpa_s->ptksa, wpa_s->own_addr, addr, cipher, life_time,
-			ptk);
+			ptk, NULL, NULL);
 }
 
 #endif /* CONFIG_NO_WPA */