FT: Fix PTK configuration in authenticator

Must update sm->pairwise when fetching PMK-R1 SA.
Add a workaround for drivers that cannot set keys before association
(e.g., cfg80211/mac80211): retry PTK configuration after association.

src/ap/wpa_auth.c

@@ -1210,6 +1210,11 @@ int wpa_auth_sm_event(struct wpa_state_machine *sm, wpa_event event)
 		break;
 	case WPA_ASSOC_FT:
 #ifdef CONFIG_IEEE80211R
+		if (!sm->pairwise_set) {
+			wpa_printf(MSG_DEBUG, "FT: Retry PTK configuration "
+				   "after association");
+			wpa_ft_install_ptk(sm);
+		}
 		/* Using FT protocol, not WPA auth state machine */
 		sm->ft_completed = 1;
 		return 0;

src/ap/wpa_auth_ft.c

@@ -852,7 +852,7 @@ static inline int wpa_auth_set_key(struct wpa_authenticator *wpa_auth,
 }
 
 
-static void wpa_ft_install_ptk(struct wpa_state_machine *sm)
+void wpa_ft_install_ptk(struct wpa_state_machine *sm)
 {
 	enum wpa_alg alg;
 	int klen;
@@ -864,13 +864,17 @@ static void wpa_ft_install_ptk(struct wpa_state_machine *sm)
 	} else if (sm->pairwise == WPA_CIPHER_CCMP) {
 		alg = WPA_ALG_CCMP;
 		klen = 16;
-	} else
+	} else {
+		wpa_printf(MSG_DEBUG, "FT: Unknown pairwise alg 0x%x - skip "
+			   "PTK configuration", sm->pairwise);
 		return;
+	}
 
 	/* FIX: add STA entry to kernel/driver here? The set_key will fail
 	 * most likely without this.. At the moment, STA entry is added only
-	 * after association has been completed. Alternatively, could
-	 * re-configure PTK at that point(?).
+	 * after association has been completed. This function will be called
+	 * again after association to get the PTK configured, but that could be
+	 * optimized by adding the STA entry earlier.
 	 */
 	if (wpa_auth_set_key(sm->wpa_auth, 0, alg, sm->addr, 0,
 			     sm->PTK.tk1, klen))
@@ -990,6 +994,7 @@ static u16 wpa_ft_process_auth_req(struct wpa_state_machine *sm,
 			(u8 *) &sm->PTK, ptk_len);
 	wpa_hexdump(MSG_DEBUG, "FT: PTKName", ptk_name, WPA_PMK_NAME_LEN);
 
+	sm->pairwise = pairwise;
 	wpa_ft_install_ptk(sm);
 
 	buflen = 2 + sizeof(struct rsn_mdie) + 2 + sizeof(struct rsn_ftie) +

src/ap/wpa_auth_i.h

@@ -216,6 +216,7 @@ int wpa_auth_derive_ptk_ft(struct wpa_state_machine *sm, const u8 *pmk,
 			   struct wpa_ptk *ptk, size_t ptk_len);
 struct wpa_ft_pmk_cache * wpa_ft_pmk_cache_init(void);
 void wpa_ft_pmk_cache_deinit(struct wpa_ft_pmk_cache *cache);
+void wpa_ft_install_ptk(struct wpa_state_machine *sm);
 #endif /* CONFIG_IEEE80211R */
 
 #endif /* WPA_AUTH_I_H */