HS 2.0: Include HS 2.0 Indication element only for HS 2.0 association

The Hotspot 2.0 specification seems to mandate this element to be
included in all (Re)Association Request frames if the station is Hotspot
2.0 capable. However, that results in conflicts with other requirements
like no TKIP use when this element is present. The design is really
supposed to include the indication element only for Hotspot 2.0
associations regardless of what the current specification implies.
Remove the HS 2.0 Indication element from (Re)Association Request frame
whenever the connection is not for Hotspot 2.0 purposes.

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

wpa_supplicant/hs20_supplicant.c

@@ -33,6 +33,35 @@ void wpas_hs20_add_indication(struct wpabuf *buf)
 }
 
 
+int is_hs20_network(struct wpa_supplicant *wpa_s, struct wpa_ssid *ssid,
+		    struct wpa_bss *bss)
+{
+	if (!wpa_s->conf->hs20 || !ssid)
+		return 0;
+
+	if (ssid->parent_cred)
+		return 1;
+
+	if (bss && !wpa_bss_get_vendor_ie(bss, HS20_IE_VENDOR_TYPE))
+		return 0;
+
+	/*
+	 * This may catch some non-Hotspot 2.0 cases, but it is safer to do that
+	 * than cause Hotspot 2.0 connections without indication element getting
+	 * added. Non-Hotspot 2.0 APs should ignore the unknown vendor element.
+	 */
+
+	if (!(ssid->key_mgmt & WPA_KEY_MGMT_IEEE8021X))
+		return 0;
+	if (!(ssid->pairwise_cipher & WPA_CIPHER_CCMP))
+		return 0;
+	if (ssid->proto != WPA_PROTO_RSN)
+		return 0;
+
+	return 1;
+}
+
+
 struct wpabuf * hs20_build_anqp_req(u32 stypes, const u8 *payload,
 				    size_t payload_len)
 {

wpa_supplicant/hs20_supplicant.h

@@ -16,5 +16,7 @@ struct wpabuf * hs20_build_anqp_req(u32 stypes, const u8 *payload,
 				    size_t payload_len);
 void hs20_parse_rx_hs20_anqp_resp(struct wpa_supplicant *wpa_s,
 				  const u8 *sa, const u8 *data, size_t slen);
+int is_hs20_network(struct wpa_supplicant *wpa_s, struct wpa_ssid *ssid,
+		    struct wpa_bss *bss);
 
 #endif /* HS20_SUPPLICANT_H */

wpa_supplicant/sme.c

@@ -353,7 +353,7 @@ static void sme_send_authentication(struct wpa_supplicant *wpa_s,
 #endif /* CONFIG_P2P */
 
 #ifdef CONFIG_HS20
-	if (wpa_s->conf->hs20) {
+	if (is_hs20_network(wpa_s, ssid, bss)) {
 		struct wpabuf *hs20;
 		hs20 = wpabuf_alloc(20);
 		if (hs20) {

wpa_supplicant/wpa_supplicant.c

@@ -1466,7 +1466,7 @@ void wpa_supplicant_associate(struct wpa_supplicant *wpa_s,
 #endif /* CONFIG_P2P */
 
 #ifdef CONFIG_HS20
-	if (wpa_s->conf->hs20) {
+	if (is_hs20_network(wpa_s, ssid, bss)) {
 		struct wpabuf *hs20;
 		hs20 = wpabuf_alloc(20);
 		if (hs20) {