SAE: Free temporary buffers when moving to Accepted state

Most of the variables are not needed anymore once the SAE instance
has entered Accepted state. Free these to save memory.

Signed-hostap: Jouni Malinen <j@w1.fi>

src/ap/ieee802_11.c

@@ -510,8 +510,10 @@ static void handle_auth_sae(struct hostapd_data *hapd, struct sta_info *sta,
 			data = auth_build_sae_confirm(hapd, sta);
 			if (data == NULL)
 				resp = WLAN_STATUS_UNSPECIFIED_FAILURE;
-			else
+			else {
 				sta->sae->state = SAE_ACCEPTED;
+				sae_clear_temp_data(sta->sae);
+			}
 		}
 	} else {
 		hostapd_logger(hapd, sta->addr, HOSTAPD_MODULE_IEEE80211,

src/common/sae.c

@@ -65,22 +65,44 @@ int sae_set_group(struct sae_data *sae, int group)
 }
 
 
-void sae_clear_data(struct sae_data *sae)
+void sae_clear_temp_data(struct sae_data *sae)
 {
 	if (sae == NULL)
 		return;
 	crypto_ec_deinit(sae->ec);
+	sae->ec = NULL;
+	sae->dh = NULL;
 	crypto_bignum_deinit(sae->prime_buf, 0);
+	sae->prime_buf = NULL;
+	sae->prime = NULL;
 	crypto_bignum_deinit(sae->order_buf, 0);
+	sae->order_buf = NULL;
+	sae->order = NULL;
 	crypto_bignum_deinit(sae->sae_rand, 1);
+	sae->sae_rand = NULL;
 	crypto_bignum_deinit(sae->pwe_ffc, 1);
+	sae->pwe_ffc = NULL;
 	crypto_bignum_deinit(sae->own_commit_scalar, 0);
-	crypto_bignum_deinit(sae->peer_commit_scalar, 0);
+	sae->own_commit_scalar = NULL;
 	crypto_bignum_deinit(sae->own_commit_element_ffc, 0);
+	sae->own_commit_element_ffc = NULL;
 	crypto_bignum_deinit(sae->peer_commit_element_ffc, 0);
+	sae->peer_commit_element_ffc = NULL;
 	crypto_ec_point_deinit(sae->pwe_ecc, 1);
+	sae->pwe_ecc = NULL;
 	crypto_ec_point_deinit(sae->own_commit_element_ecc, 0);
+	sae->own_commit_element_ecc = NULL;
 	crypto_ec_point_deinit(sae->peer_commit_element_ecc, 0);
+	sae->peer_commit_element_ecc = NULL;
+}
+
+
+void sae_clear_data(struct sae_data *sae)
+{
+	if (sae == NULL)
+		return;
+	sae_clear_temp_data(sae);
+	crypto_bignum_deinit(sae->peer_commit_scalar, 0);
 	os_memset(sae, 0, sizeof(*sae));
 }
 

src/common/sae.h

@@ -43,6 +43,7 @@ struct sae_data {
 };
 
 int sae_set_group(struct sae_data *sae, int group);
+void sae_clear_temp_data(struct sae_data *sae);
 void sae_clear_data(struct sae_data *sae);
 
 int sae_prepare_commit(const u8 *addr1, const u8 *addr2,

wpa_supplicant/sme.c

@@ -511,6 +511,7 @@ static int sme_sae_auth(struct wpa_supplicant *wpa_s, u16 auth_transaction,
 		if (sae_check_confirm(&wpa_s->sme.sae, data, len) < 0)
 			return -1;
 		wpa_s->sme.sae.state = SAE_ACCEPTED;
+		sae_clear_temp_data(&wpa_s->sme.sae);
 		return 1;
 	}