Do not allow HT with WPA/WPA2 to be enabled without CCMP

IEEE 802.11n does not allow HT STAs to use TKIP between themselves, so
do do allow a configuration that would force this to happen if HT is
used.

hostapd/config.c

@@ -944,6 +944,16 @@ static int hostapd_config_check_bss(struct hostapd_bss_config *bss,
 	}
 #endif /* CONFIG_IEEE80211R */
 
+#ifdef CONFIG_IEEE80211N
+	if (conf->ieee80211n && bss->wpa &&
+	    !(bss->wpa_pairwise & WPA_CIPHER_CCMP) &&
+	    !(bss->rsn_pairwise & WPA_CIPHER_CCMP)) {
+		printf("HT (IEEE 802.11n) with WPA/WPA2 requires CCMP to be "
+		       "enabled\n");
+		return -1;
+	}
+#endif /* CONFIG_IEEE80211N */
+
 	return 0;
 }