ERP: Add optional EAP-Initiate/Re-auth-Start transmission

hostapd can now be configured to transmit EAP-Initiate/Re-auth-Start
before EAP-Request/Identity to try to initiate ERP. This is disabled by
default and can be enabled with erp_send_reauth_start=1 and optional
erp_reauth_start_domain=<domain>.

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

hostapd/config_file.c

@@ -2071,6 +2071,11 @@ static int hostapd_config_fill(struct hostapd_config *conf,
 				   (term - bss->eap_req_id_text) - 1);
 			bss->eap_req_id_text_len--;
 		}
+	} else if (os_strcmp(buf, "erp_send_reauth_start") == 0) {
+		bss->erp_send_reauth_start = atoi(pos);
+	} else if (os_strcmp(buf, "erp_domain") == 0) {
+		os_free(bss->erp_domain);
+		bss->erp_domain = os_strdup(pos);
 	} else if (os_strcmp(buf, "wep_key_len_broadcast") == 0) {
 		bss->default_wep_key_len = atoi(pos);
 		if (bss->default_wep_key_len > 13) {

hostapd/hostapd.conf

@@ -696,6 +696,16 @@ eapol_key_index_workaround=0
 # is only used by one station.
 #use_pae_group_addr=1
 
+# EAP Re-authentication Protocol (ERP) authenticator (RFC 6696)
+#
+# Whether to initiate EAP authentication with EAP-Initiate/Re-auth-Start before
+# EAP-Identity/Request
+#erp_send_reauth_start=1
+#
+# Domain name for EAP-Initiate/Re-auth-Start. Omitted from the message if not
+# set (no local ER server).
+#erp_domain=example.com
+
 ##### Integrated EAP server ###################################################
 
 # Optionally, hostapd can be configured to use an integrated EAP server

src/ap/ap_config.c

@@ -425,6 +425,7 @@ void hostapd_config_free_bss(struct hostapd_bss_config *conf)
 	os_free(conf->eap_user_sqlite);
 
 	os_free(conf->eap_req_id_text);
+	os_free(conf->erp_domain);
 	os_free(conf->accept_mac);
 	os_free(conf->deny_mac);
 	os_free(conf->nas_identifier);

src/ap/ap_config.h

@@ -259,6 +259,8 @@ struct hostapd_bss_config {
 	int wep_rekeying_period;
 	int broadcast_key_idx_min, broadcast_key_idx_max;
 	int eap_reauth_period;
+	int erp_send_reauth_start;
+	char *erp_domain;
 
 	int ieee802_11f; /* use IEEE 802.11f (IAPP) */
 	char iapp_iface[IFNAMSIZ + 1]; /* interface used with IAPP broadcast

src/ap/ieee802_1x.c

@@ -2003,6 +2003,8 @@ int ieee802_1x_init(struct hostapd_data *hapd)
 	conf.eap_sim_db_priv = hapd->eap_sim_db_priv;
 	conf.eap_req_id_text = hapd->conf->eap_req_id_text;
 	conf.eap_req_id_text_len = hapd->conf->eap_req_id_text_len;
+	conf.erp_send_reauth_start = hapd->conf->erp_send_reauth_start;
+	conf.erp_domain = hapd->conf->erp_domain;
 	conf.pac_opaque_encr_key = hapd->conf->pac_opaque_encr_key;
 	conf.eap_fast_a_id = hapd->conf->eap_fast_a_id;
 	conf.eap_fast_a_id_len = hapd->conf->eap_fast_a_id_len;

src/eap_server/eap.h

@@ -85,6 +85,8 @@ struct eapol_callbacks {
 			    int phase2, struct eap_user *user);
 	const char * (*get_eap_req_id_text)(void *ctx, size_t *len);
 	void (*log_msg)(void *ctx, const char *msg);
+	int (*get_erp_send_reauth_start)(void *ctx);
+	const char * (*get_erp_domain)(void *ctx);
 };
 
 struct eap_config {

src/eap_server/eap_i.h

@@ -116,7 +116,8 @@ struct eap_sm {
 		EAP_INITIALIZE_PASSTHROUGH, EAP_IDLE2, EAP_RETRANSMIT2,
 		EAP_RECEIVED2, EAP_DISCARD2, EAP_SEND_REQUEST2,
 		EAP_AAA_REQUEST, EAP_AAA_RESPONSE, EAP_AAA_IDLE,
-		EAP_TIMEOUT_FAILURE2, EAP_FAILURE2, EAP_SUCCESS2
+		EAP_TIMEOUT_FAILURE2, EAP_FAILURE2, EAP_SUCCESS2,
+		EAP_INITIATE_REAUTH_START
 	} EAP_state;
 
 	/* Constants */
@@ -145,7 +146,7 @@ struct eap_sm {
 	Boolean ignore;
 	enum {
 		DECISION_SUCCESS, DECISION_FAILURE, DECISION_CONTINUE,
-		DECISION_PASSTHROUGH
+		DECISION_PASSTHROUGH, DECISION_INITIATE_REAUTH_START
 	} decision;
 
 	/* Miscellaneous variables */
@@ -205,6 +206,9 @@ struct eap_sm {
 	const u8 *server_id;
 	size_t server_id_len;
 
+	Boolean initiate_reauth_start_sent;
+	Boolean try_initiate_reauth;
+
 #ifdef CONFIG_TESTING_OPTIONS
 	u32 tls_test_flags;
 #endif /* CONFIG_TESTING_OPTIONS */

src/eap_server/eap_server.c

@@ -1,6 +1,6 @@
 /*
  * hostapd / EAP Full Authenticator state machine (RFC 4137)
- * Copyright (c) 2004-2007, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2004-2014, Jouni Malinen <j@w1.fi>
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
@@ -44,6 +44,52 @@ static int eap_sm_Policy_getDecision(struct eap_sm *sm);
 static Boolean eap_sm_Policy_doPickUp(struct eap_sm *sm, EapType method);
 
 
+static int eap_get_erp_send_reauth_start(struct eap_sm *sm)
+{
+	if (sm->eapol_cb->get_erp_send_reauth_start)
+		return sm->eapol_cb->get_erp_send_reauth_start(sm->eapol_ctx);
+	return 0;
+}
+
+
+static const char * eap_get_erp_domain(struct eap_sm *sm)
+{
+	if (sm->eapol_cb->get_erp_domain)
+		return sm->eapol_cb->get_erp_domain(sm->eapol_ctx);
+	return NULL;
+}
+
+
+static struct wpabuf * eap_sm_buildInitiateReauthStart(struct eap_sm *sm,
+						       u8 id)
+{
+	const char *domain;
+	size_t plen = 1;
+	struct wpabuf *msg;
+	size_t domain_len = 0;
+
+	domain = eap_get_erp_domain(sm);
+	if (domain) {
+		domain_len = os_strlen(domain);
+		plen += 2 + domain_len;;
+	}
+
+	msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_ERP_TYPE_REAUTH_START, plen,
+			    EAP_CODE_INITIATE, id);
+	if (msg == NULL)
+		return NULL;
+	wpabuf_put_u8(msg, 0); /* Reserved */
+	if (domain) {
+		/* Domain name TLV */
+		wpabuf_put_u8(msg, EAP_ERP_TLV_DOMAIN_NAME);
+		wpabuf_put_u8(msg, domain_len);
+		wpabuf_put_data(msg, domain, domain_len);
+	}
+
+	return msg;
+}
+
+
 static int eap_copy_buf(struct wpabuf **dst, const struct wpabuf *src)
 {
 	if (src == NULL)
@@ -164,6 +210,8 @@ SM_STATE(EAP, INITIALIZE)
 		eap_server_clear_identity(sm);
 	}
 
+	sm->initiate_reauth_start_sent = FALSE;
+	sm->try_initiate_reauth = FALSE;
 	sm->currentId = -1;
 	sm->eap_if.eapSuccess = FALSE;
 	sm->eap_if.eapFail = FALSE;
@@ -382,6 +430,7 @@ SM_STATE(EAP, PROPOSE_METHOD)
 
 	SM_ENTRY(EAP, PROPOSE_METHOD);
 
+	sm->try_initiate_reauth = FALSE;
 try_another_method:
 	type = eap_sm_Policy_getNextMethod(sm, &vendor);
 	if (vendor == EAP_VENDOR_IETF)
@@ -505,6 +554,25 @@ SM_STATE(EAP, SUCCESS)
 }
 
 
+SM_STATE(EAP, INITIATE_REAUTH_START)
+{
+	SM_ENTRY(EAP, INITIATE_REAUTH_START);
+
+	sm->initiate_reauth_start_sent = TRUE;
+	sm->try_initiate_reauth = TRUE;
+	sm->currentId = eap_sm_nextId(sm, sm->currentId);
+	wpa_printf(MSG_DEBUG,
+		   "EAP: building EAP-Initiate-Re-auth-Start: Identifier %d",
+		   sm->currentId);
+	sm->lastId = sm->currentId;
+	wpabuf_free(sm->eap_if.eapReqData);
+	sm->eap_if.eapReqData = eap_sm_buildInitiateReauthStart(sm,
+								sm->currentId);
+	wpabuf_free(sm->lastReqData);
+	sm->lastReqData = NULL;
+}
+
+
 SM_STATE(EAP, INITIALIZE_PASSTHROUGH)
 {
 	SM_ENTRY(EAP, INITIALIZE_PASSTHROUGH);
@@ -704,9 +772,14 @@ SM_STEP(EAP)
 			SM_ENTER(EAP, INITIALIZE);
 		break;
 	case EAP_IDLE:
-		if (sm->eap_if.retransWhile == 0)
+		if (sm->eap_if.retransWhile == 0) {
+			if (sm->try_initiate_reauth) {
+				sm->try_initiate_reauth = FALSE;
+				SM_ENTER(EAP, SELECT_ACTION);
+			} else {
 				SM_ENTER(EAP, RETRANSMIT);
-		else if (sm->eap_if.eapResp)
+			}
+		} else if (sm->eap_if.eapResp)
 			SM_ENTER(EAP, RECEIVED);
 		break;
 	case EAP_RETRANSMIT:
@@ -817,9 +890,14 @@ SM_STEP(EAP)
 			SM_ENTER(EAP, SUCCESS);
 		else if (sm->decision == DECISION_PASSTHROUGH)
 			SM_ENTER(EAP, INITIALIZE_PASSTHROUGH);
+		else if (sm->decision == DECISION_INITIATE_REAUTH_START)
+			SM_ENTER(EAP, INITIATE_REAUTH_START);
 		else
 			SM_ENTER(EAP, PROPOSE_METHOD);
 		break;
+	case EAP_INITIATE_REAUTH_START:
+		SM_ENTER(EAP, SEND_REQUEST);
+		break;
 	case EAP_TIMEOUT_FAILURE:
 		break;
 	case EAP_FAILURE:
@@ -889,6 +967,12 @@ static int eap_sm_calculateTimeout(struct eap_sm *sm, int retransCount,
 {
 	int rto, i;
 
+	if (sm->try_initiate_reauth) {
+		wpa_printf(MSG_DEBUG,
+			   "EAP: retransmit timeout 1 second for EAP-Initiate-Re-auth-Start");
+		return 1;
+	}
+
 	if (methodTimeout) {
 		/*
 		 * EAP method (either internal or through AAA server, provided
@@ -1229,6 +1313,13 @@ static int eap_sm_Policy_getDecision(struct eap_sm *sm)
 		return DECISION_CONTINUE;
 	}
 
+	if (!sm->identity && eap_get_erp_send_reauth_start(sm) &&
+	    !sm->initiate_reauth_start_sent) {
+		wpa_printf(MSG_DEBUG,
+			   "EAP: getDecision: send EAP-Initiate/Re-auth-Start");
+		return DECISION_INITIATE_REAUTH_START;
+	}
+
 	if (sm->identity == NULL || sm->currentId == -1) {
 		wpa_printf(MSG_DEBUG, "EAP: getDecision: no identity known "
 			   "yet -> CONTINUE");

src/eapol_auth/eapol_auth_sm.c

@@ -1,6 +1,6 @@
 /*
  * IEEE 802.1X-2004 Authenticator - EAPOL state machine
- * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2002-2014, Jouni Malinen <j@w1.fi>
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
@@ -43,6 +43,7 @@ sm->eapol->cb.set_port_authorized(sm->eapol->conf.ctx, sm->sta, 0)
 static void eapol_sm_step_run(struct eapol_state_machine *sm);
 static void eapol_sm_step_cb(void *eloop_ctx, void *timeout_ctx);
 static void eapol_auth_initialize(struct eapol_state_machine *sm);
+static void eapol_auth_conf_free(struct eapol_auth_config *conf);
 
 
 static void eapol_auth_logger(struct eapol_authenticator *eapol,
@@ -1025,11 +1026,27 @@ static const char * eapol_sm_get_eap_req_id_text(void *ctx, size_t *len)
 }
 
 
+static int eapol_sm_get_erp_send_reauth_start(void *ctx)
+{
+	struct eapol_state_machine *sm = ctx;
+	return sm->eapol->conf.erp_send_reauth_start;
+}
+
+
+static const char * eapol_sm_get_erp_domain(void *ctx)
+{
+	struct eapol_state_machine *sm = ctx;
+	return sm->eapol->conf.erp_domain;
+}
+
+
 static struct eapol_callbacks eapol_cb =
 {
 	eapol_sm_get_eap_user,
 	eapol_sm_get_eap_req_id_text,
-	NULL
+	NULL,
+	eapol_sm_get_erp_send_reauth_start,
+	eapol_sm_get_erp_domain,
 };
 
 
@@ -1074,21 +1091,16 @@ static int eapol_auth_conf_clone(struct eapol_auth_config *dst,
 	}
 	if (src->pac_opaque_encr_key) {
 		dst->pac_opaque_encr_key = os_malloc(16);
-		if (dst->pac_opaque_encr_key == NULL) {
-			os_free(dst->eap_req_id_text);
-			return -1;
-		}
+		if (dst->pac_opaque_encr_key == NULL)
+			goto fail;
 		os_memcpy(dst->pac_opaque_encr_key, src->pac_opaque_encr_key,
 			  16);
 	} else
 		dst->pac_opaque_encr_key = NULL;
 	if (src->eap_fast_a_id) {
 		dst->eap_fast_a_id = os_malloc(src->eap_fast_a_id_len);
-		if (dst->eap_fast_a_id == NULL) {
-			os_free(dst->eap_req_id_text);
-			os_free(dst->pac_opaque_encr_key);
-			return -1;
-		}
+		if (dst->eap_fast_a_id == NULL)
+			goto fail;
 		os_memcpy(dst->eap_fast_a_id, src->eap_fast_a_id,
 			  src->eap_fast_a_id_len);
 		dst->eap_fast_a_id_len = src->eap_fast_a_id_len;
@@ -1096,12 +1108,8 @@ static int eapol_auth_conf_clone(struct eapol_auth_config *dst,
 		dst->eap_fast_a_id = NULL;
 	if (src->eap_fast_a_id_info) {
 		dst->eap_fast_a_id_info = os_strdup(src->eap_fast_a_id_info);
-		if (dst->eap_fast_a_id_info == NULL) {
-			os_free(dst->eap_req_id_text);
-			os_free(dst->pac_opaque_encr_key);
-			os_free(dst->eap_fast_a_id);
-			return -1;
-		}
+		if (dst->eap_fast_a_id_info == NULL)
+			goto fail;
 	} else
 		dst->eap_fast_a_id_info = NULL;
 	dst->eap_fast_prov = src->eap_fast_prov;
@@ -1111,7 +1119,22 @@ static int eapol_auth_conf_clone(struct eapol_auth_config *dst,
 	dst->tnc = src->tnc;
 	dst->wps = src->wps;
 	dst->fragment_size = src->fragment_size;
+
+	os_free(dst->erp_domain);
+	if (src->erp_domain) {
+		dst->erp_domain = os_strdup(src->erp_domain);
+		if (dst->erp_domain == NULL)
+			goto fail;
+	} else {
+		dst->erp_domain = NULL;
+	}
+	dst->erp_send_reauth_start = src->erp_send_reauth_start;
+
 	return 0;
+
+fail:
+	eapol_auth_conf_free(dst);
+	return -1;
 }
 
 
@@ -1125,6 +1148,8 @@ static void eapol_auth_conf_free(struct eapol_auth_config *conf)
 	conf->eap_fast_a_id = NULL;
 	os_free(conf->eap_fast_a_id_info);
 	conf->eap_fast_a_id_info = NULL;
+	os_free(conf->erp_domain);
+	conf->erp_domain = NULL;
 }
 
 

src/eapol_auth/eapol_auth_sm.h

@@ -24,6 +24,8 @@ struct eapol_auth_config {
 	void *eap_sim_db_priv;
 	char *eap_req_id_text; /* a copy of this will be allocated */
 	size_t eap_req_id_text_len;
+	int erp_send_reauth_start;
+	char *erp_domain; /* a copy of this will be allocated */
 	u8 *pac_opaque_encr_key;
 	u8 *eap_fast_a_id;
 	size_t eap_fast_a_id_len;

src/radius/radius_server.c

@@ -2022,6 +2022,8 @@ static struct eapol_callbacks radius_server_eapol_cb =
 	.get_eap_user = radius_server_get_eap_user,
 	.get_eap_req_id_text = radius_server_get_eap_req_id_text,
 	.log_msg = radius_server_log_msg,
+	NULL,
+	NULL,
 };