From 43b20b4370a82a3274794bea6eee7c1218142881 Mon Sep 17 00:00:00 2001
From: Jouni Malinen <jouni@codeaurora.org>
Date: Fri, 6 Sep 2019 15:51:37 +0300
Subject: [PATCH] SAE: Derive H2E PT in AP when starting the AP

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
---
 hostapd/ctrl_iface.c |  5 +++++
 src/ap/ap_config.c   | 47 ++++++++++++++++++++++++++++++++++++++++++++
 src/ap/ap_config.h   |  3 +++
 3 files changed, 55 insertions(+)

diff --git a/hostapd/ctrl_iface.c b/hostapd/ctrl_iface.c
index 8d9d1a3be..2c44d1e4e 100644
--- a/hostapd/ctrl_iface.c
+++ b/hostapd/ctrl_iface.c
@@ -1424,6 +1424,11 @@ static int hostapd_ctrl_iface_set(struct hostapd_data *hapd, char *cmd)
 			if (ieee802_11_update_beacons(hapd->iface))
 				wpa_printf(MSG_DEBUG,
 					   "Failed to update beacons with WMM parameters");
+		} else if (os_strcmp(cmd, "wpa_passphrase") == 0 ||
+			   os_strcmp(cmd, "sae_password") == 0 ||
+			   os_strcmp(cmd, "sae_pwe") == 0) {
+			if (hapd->started)
+				hostapd_setup_sae_pt(hapd->conf);
 		}
 	}
 
diff --git a/src/ap/ap_config.c b/src/ap/ap_config.c
index 6704ade4e..58fc3e988 100644
--- a/src/ap/ap_config.c
+++ b/src/ap/ap_config.c
@@ -16,6 +16,7 @@
 #include "common/ieee802_1x_defs.h"
 #include "common/eapol_common.h"
 #include "common/dhcp.h"
+#include "common/sae.h"
 #include "eap_common/eap_wsc_common.h"
 #include "eap_server/eap.h"
 #include "wpa_auth.h"
@@ -434,10 +435,50 @@ static int hostapd_derive_psk(struct hostapd_ssid *ssid)
 }
 
 
+int hostapd_setup_sae_pt(struct hostapd_bss_config *conf)
+{
+#ifdef CONFIG_SAE
+	struct hostapd_ssid *ssid = &conf->ssid;
+	struct sae_password_entry *pw;
+
+	if (conf->sae_pwe == 0)
+		return 0; /* PT not needed */
+
+	sae_deinit_pt(ssid->pt);
+	ssid->pt = NULL;
+	if (ssid->wpa_passphrase) {
+		ssid->pt = sae_derive_pt(conf->sae_groups, ssid->ssid,
+					 ssid->ssid_len,
+					 (const u8 *) ssid->wpa_passphrase,
+					 os_strlen(ssid->wpa_passphrase),
+					 NULL);
+		if (!ssid->pt)
+			return -1;
+	}
+
+	for (pw = conf->sae_passwords; pw; pw = pw->next) {
+		sae_deinit_pt(pw->pt);
+		pw->pt = sae_derive_pt(conf->sae_groups, ssid->ssid,
+				       ssid->ssid_len,
+				       (const u8 *) pw->password,
+				       os_strlen(pw->password),
+				       pw->identifier);
+		if (!pw->pt)
+			return -1;
+	}
+#endif /* CONFIG_SAE */
+
+	return 0;
+}
+
+
 int hostapd_setup_wpa_psk(struct hostapd_bss_config *conf)
 {
 	struct hostapd_ssid *ssid = &conf->ssid;
 
+	if (hostapd_setup_sae_pt(conf) < 0)
+		return -1;
+
 	if (ssid->wpa_passphrase != NULL) {
 		if (ssid->wpa_psk != NULL) {
 			wpa_printf(MSG_DEBUG, "Using pre-configured WPA PSK "
@@ -643,6 +684,9 @@ static void hostapd_config_free_sae_passwords(struct hostapd_bss_config *conf)
 		pw = pw->next;
 		str_clear_free(tmp->password);
 		os_free(tmp->identifier);
+#ifdef CONFIG_SAE
+		sae_deinit_pt(tmp->pt);
+#endif /* CONFIG_SAE */
 		os_free(tmp);
 	}
 }
@@ -679,6 +723,9 @@ void hostapd_config_free_bss(struct hostapd_bss_config *conf)
 #ifdef CONFIG_FULL_DYNAMIC_VLAN
 	os_free(conf->ssid.vlan_tagged_interface);
 #endif /* CONFIG_FULL_DYNAMIC_VLAN */
+#ifdef CONFIG_SAE
+	sae_deinit_pt(conf->ssid.pt);
+#endif /* CONFIG_SAE */
 
 	hostapd_config_free_eap_users(conf->eap_user);
 	os_free(conf->eap_user_sqlite);
diff --git a/src/ap/ap_config.h b/src/ap/ap_config.h
index 2d09d0614..0aa8e0d68 100644
--- a/src/ap/ap_config.h
+++ b/src/ap/ap_config.h
@@ -99,6 +99,7 @@ struct hostapd_ssid {
 	struct hostapd_wpa_psk *wpa_psk;
 	char *wpa_passphrase;
 	char *wpa_psk_file;
+	struct sae_pt *pt;
 
 	struct hostapd_wep_keys wep;
 
@@ -251,6 +252,7 @@ struct sae_password_entry {
 	char *identifier;
 	u8 peer_addr[ETH_ALEN];
 	int vlan_id;
+	struct sae_pt *pt;
 };
 
 struct dpp_controller_conf {
@@ -1104,5 +1106,6 @@ 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);
+int hostapd_setup_sae_pt(struct hostapd_bss_config *conf);
 
 #endif /* HOSTAPD_CONFIG_H */