SAE: Advertise Password Identifier use

Support the new Extended Capabilities field bits 81 and 82 to indicate
whether SAe Password Identifiers are in use.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>

src/ap/ap_config.c

@@ -1168,3 +1168,26 @@ void hostapd_set_security_params(struct hostapd_bss_config *bss,
 		}
 	}
 }
+
+
+int hostapd_sae_pw_id_in_use(struct hostapd_bss_config *conf)
+{
+	int with_id = 0, without_id = 0;
+	struct sae_password_entry *pw;
+
+	if (conf->ssid.wpa_passphrase)
+		without_id = 1;
+
+	for (pw = conf->sae_passwords; pw; pw = pw->next) {
+		if (pw->identifier)
+			with_id = 1;
+		else
+			without_id = 1;
+		if (with_id && without_id)
+			break;
+	}
+
+	if (with_id && !without_id)
+		return 2;
+	return with_id;
+}

src/ap/ap_config.h

@@ -880,5 +880,6 @@ hostapd_config_get_radius_attr(struct hostapd_radius_attr *attr, u8 type);
 int hostapd_config_check(struct hostapd_config *conf, int full_config);
 void hostapd_set_security_params(struct hostapd_bss_config *bss,
 				 int full_config);
+int hostapd_sae_pw_id_in_use(struct hostapd_bss_config *conf);
 
 #endif /* HOSTAPD_CONFIG_H */

src/ap/ieee802_11_shared.c

@@ -372,6 +372,21 @@ static void hostapd_ext_capab_byte(struct hostapd_data *hapd, u8 *pos, int idx)
 			*pos |= 0x01;
 #endif /* CONFIG_FILS */
 		break;
+	case 10: /* Bits 80-87 */
+#ifdef CONFIG_SAE
+		if (hapd->conf->wpa &&
+		    wpa_key_mgmt_sae(hapd->conf->wpa_key_mgmt)) {
+			int in_use = hostapd_sae_pw_id_in_use(hapd->conf);
+
+			if (in_use)
+				*pos |= 0x02; /* Bit 81 - SAE Password
+					       * Identifiers In Use */
+			if (in_use == 2)
+				*pos |= 0x04; /* Bit 82 - SAE Password
+					       * Identifiers Used Exclusively */
+		}
+#endif /* CONFIG_SAE */
+		break;
 	}
 }
 
@@ -411,6 +426,12 @@ u8 * hostapd_eid_ext_capab(struct hostapd_data *hapd, u8 *eid)
 	     !wpa_key_mgmt_fils(hapd->conf->wpa_key_mgmt)) && len < 10)
 		len = 10;
 #endif /* CONFIG_FILS */
+#ifdef CONFIG_SAE
+	if (len < 11 && hapd->conf->wpa &&
+	    wpa_key_mgmt_sae(hapd->conf->wpa_key_mgmt) &&
+	    hostapd_sae_pw_id_in_use(hapd->conf))
+		len = 11;
+#endif /* CONFIG_SAE */
 	if (len < hapd->iface->extended_capa_len)
 		len = hapd->iface->extended_capa_len;
 	if (len == 0)