Interworking: Reject EAP configuration with unsupported inner method

Instead of allowing the connection attempt to occur with an unsupported
inner method, check for that explicitly at the time the network block is
added and drop the network if the identified inner method is not
supported.

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

wpa_supplicant/interworking.c

@@ -1515,6 +1515,7 @@ static int interworking_connect_helper(struct wpa_supplicant *wpa_s,
 	u16 count, i;
 	char buf[100];
 	int excluded = 0, *excl = allow_excluded ? &excluded : NULL;
+	const char *name;
 
 	if (wpa_s->conf->cred == NULL || bss == NULL)
 		return -1;
@@ -1728,11 +1729,12 @@ static int interworking_connect_helper(struct wpa_supplicant *wpa_s,
 		if (wpa_config_set(ssid, "pac_file",
 				   "\"blob://pac_interworking\"", 0) < 0)
 			goto fail;
-		os_snprintf(buf, sizeof(buf), "\"auth=%s\"",
-			    eap_get_name(EAP_VENDOR_IETF,
-					 eap->inner_method ?
-					 eap->inner_method :
-					 EAP_TYPE_MSCHAPV2));
+		name = eap_get_name(EAP_VENDOR_IETF,
+				    eap->inner_method ? eap->inner_method :
+				    EAP_TYPE_MSCHAPV2);
+		if (name == NULL)
+			goto fail;
+		os_snprintf(buf, sizeof(buf), "\"auth=%s\"", name);
 		if (wpa_config_set(ssid, "phase2", buf, 0) < 0)
 			goto fail;
 		break;