diff --git a/hostapd/Makefile b/hostapd/Makefile
index 74cd9fa73..dea4c1595 100644
--- a/hostapd/Makefile
+++ b/hostapd/Makefile
@@ -258,6 +258,12 @@ OBJS += ../src/l2_packet/l2_packet_none.o
 endif
 
 
+ifdef CONFIG_ERP
+CFLAGS += -DCONFIG_ERP
+NEED_SHA256=y
+NEED_HMAC_SHA256_KDF=y
+endif
+
 ifdef CONFIG_EAP_MD5
 CFLAGS += -DEAP_SERVER_MD5
 OBJS += ../src/eap_server/eap_server_md5.o
@@ -767,6 +773,9 @@ endif
 ifdef NEED_TLS_PRF_SHA256
 OBJS += ../src/crypto/sha256-tlsprf.o
 endif
+ifdef NEED_HMAC_SHA256_KDF
+OBJS += ../src/crypto/sha256-kdf.o
+endif
 endif
 
 ifdef NEED_DH_GROUPS
diff --git a/hostapd/config_file.c b/hostapd/config_file.c
index 76d89649f..c9ff3ec51 100644
--- a/hostapd/config_file.c
+++ b/hostapd/config_file.c
@@ -2052,6 +2052,8 @@ static int hostapd_config_fill(struct hostapd_config *conf,
 	} else if (os_strcmp(buf, "pwd_group") == 0) {
 		bss->pwd_group = atoi(pos);
 #endif /* EAP_SERVER_PWD */
+	} else if (os_strcmp(buf, "eap_server_erp") == 0) {
+		bss->eap_server_erp = atoi(pos);
 #endif /* EAP_SERVER */
 	} else if (os_strcmp(buf, "eap_message") == 0) {
 		char *term;
diff --git a/hostapd/defconfig b/hostapd/defconfig
index 8f8a53ff1..4cde2b563 100644
--- a/hostapd/defconfig
+++ b/hostapd/defconfig
@@ -56,6 +56,9 @@ CONFIG_IEEE80211W=y
 # Integrated EAP server
 CONFIG_EAP=y
 
+# EAP Re-authentication Protocol (ERP) in integrated EAP server
+CONFIG_ERP=y
+
 # EAP-MD5 for the integrated EAP server
 CONFIG_EAP_MD5=y
 
diff --git a/hostapd/hostapd.conf b/hostapd/hostapd.conf
index 44dacb733..2f6126c3a 100644
--- a/hostapd/hostapd.conf
+++ b/hostapd/hostapd.conf
@@ -703,7 +703,8 @@ eapol_key_index_workaround=0
 #erp_send_reauth_start=1
 #
 # Domain name for EAP-Initiate/Re-auth-Start. Omitted from the message if not
-# set (no local ER server).
+# set (no local ER server). This is also used by the integrated EAP server if
+# ERP is enabled (eap_server_erp=1).
 #erp_domain=example.com
 
 ##### Integrated EAP server ###################################################
@@ -851,6 +852,10 @@ eap_server=0
 # EAP method is enabled, the peer will be allowed to connect without TNC.
 #tnc=1
 
+# EAP Re-authentication Protocol (ERP) - RFC 6696
+#
+# Whether to enable ERP on the EAP server.
+#eap_server_erp=1
 
 ##### IEEE 802.11f - Inter-Access Point Protocol (IAPP) #######################
 
diff --git a/src/ap/ap_config.h b/src/ap/ap_config.h
index 874ce6171..64df60d34 100644
--- a/src/ap/ap_config.h
+++ b/src/ap/ap_config.h
@@ -233,6 +233,7 @@ struct hostapd_bss_config {
 	struct hostapd_eap_user *eap_user;
 	char *eap_user_sqlite;
 	char *eap_sim_db;
+	int eap_server_erp; /* Whether ERP is enabled on internal EAP server */
 	struct hostapd_ip_addr own_ip_addr;
 	char *nas_identifier;
 	struct hostapd_radius_servers *radius;
diff --git a/src/ap/authsrv.c b/src/ap/authsrv.c
index 690f1dc41..bd1778e41 100644
--- a/src/ap/authsrv.c
+++ b/src/ap/authsrv.c
@@ -124,6 +124,8 @@ static int hostapd_setup_radius_srv(struct hostapd_data *hapd)
 	srv.subscr_remediation_url = conf->subscr_remediation_url;
 	srv.subscr_remediation_method = conf->subscr_remediation_method;
 #endif /* CONFIG_HS20 */
+	srv.erp = conf->eap_server_erp;
+	srv.erp_domain = conf->erp_domain;
 
 	hapd->radius_srv = radius_server_init(&srv);
 	if (hapd->radius_srv == NULL) {
diff --git a/src/ap/hostapd.h b/src/ap/hostapd.h
index ba169f499..4a50a008d 100644
--- a/src/ap/hostapd.h
+++ b/src/ap/hostapd.h
@@ -1,6 +1,6 @@
 /*
  * hostapd / Initialization and configuration
- * Copyright (c) 2002-2013, 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.
@@ -10,6 +10,7 @@
 #define HOSTAPD_H
 
 #include "common/defs.h"
+#include "utils/list.h"
 #include "ap_config.h"
 #include "drivers/driver.h"
 
@@ -153,6 +154,7 @@ struct hostapd_data {
 	void *ssl_ctx;
 	void *eap_sim_db_priv;
 	struct radius_server_data *radius_srv;
+	struct dl_list erp_keys; /* struct eap_server_erp_key */
 
 	int parameter_set_count;
 
diff --git a/src/ap/ieee802_1x.c b/src/ap/ieee802_1x.c
index d29838564..84a98abc4 100644
--- a/src/ap/ieee802_1x.c
+++ b/src/ap/ieee802_1x.c
@@ -296,9 +296,15 @@ static void ieee802_1x_learn_identity(struct hostapd_data *hapd,
 {
 	const u8 *identity;
 	size_t identity_len;
+	const struct eap_hdr *hdr = (const struct eap_hdr *) eap;
 
 	if (len <= sizeof(struct eap_hdr) ||
-	    eap[sizeof(struct eap_hdr)] != EAP_TYPE_IDENTITY)
+	    (hdr->code == EAP_CODE_RESPONSE &&
+	     eap[sizeof(struct eap_hdr)] != EAP_TYPE_IDENTITY) ||
+	    (hdr->code == EAP_CODE_INITIATE &&
+	     eap[sizeof(struct eap_hdr)] != EAP_ERP_TYPE_REAUTH) ||
+	    (hdr->code != EAP_CODE_RESPONSE &&
+	     hdr->code != EAP_CODE_INITIATE))
 		return;
 
 	identity = eap_get_identity(sm->eap, &identity_len);
@@ -711,6 +717,39 @@ static void handle_eap_response(struct hostapd_data *hapd,
 }
 
 
+static void handle_eap_initiate(struct hostapd_data *hapd,
+				struct sta_info *sta, struct eap_hdr *eap,
+				size_t len)
+{
+#ifdef CONFIG_ERP
+	u8 type, *data;
+	struct eapol_state_machine *sm = sta->eapol_sm;
+
+	if (sm == NULL)
+		return;
+
+	if (len < sizeof(*eap) + 1) {
+		wpa_printf(MSG_INFO,
+			   "handle_eap_initiate: too short response data");
+		return;
+	}
+
+	data = (u8 *) (eap + 1);
+	type = data[0];
+
+	hostapd_logger(hapd, sm->addr, HOSTAPD_MODULE_IEEE8021X,
+		       HOSTAPD_LEVEL_DEBUG, "received EAP packet (code=%d "
+		       "id=%d len=%d) from STA: EAP Initiate type %u",
+		       eap->code, eap->identifier, be_to_host16(eap->length),
+		       type);
+
+	wpabuf_free(sm->eap_if->eapRespData);
+	sm->eap_if->eapRespData = wpabuf_alloc_copy(eap, len);
+	sm->eapolEap = TRUE;
+#endif /* CONFIG_ERP */
+}
+
+
 /* Process incoming EAP packet from Supplicant */
 static void handle_eap(struct hostapd_data *hapd, struct sta_info *sta,
 		       u8 *buf, size_t len)
@@ -754,6 +793,13 @@ static void handle_eap(struct hostapd_data *hapd, struct sta_info *sta,
 	case EAP_CODE_FAILURE:
 		wpa_printf(MSG_DEBUG, " (failure)");
 		return;
+	case EAP_CODE_INITIATE:
+		wpa_printf(MSG_DEBUG, " (initiate)");
+		handle_eap_initiate(hapd, sta, eap, eap_len);
+		break;
+	case EAP_CODE_FINISH:
+		wpa_printf(MSG_DEBUG, " (finish)");
+		break;
 	default:
 		wpa_printf(MSG_DEBUG, " (unknown code)");
 		return;
@@ -1986,12 +2032,43 @@ static void ieee802_1x_eapol_event(void *ctx, void *sta_ctx,
 }
 
 
+#ifdef CONFIG_ERP
+
+static struct eap_server_erp_key *
+ieee802_1x_erp_get_key(void *ctx, const char *keyname)
+{
+	struct hostapd_data *hapd = ctx;
+	struct eap_server_erp_key *erp;
+
+	dl_list_for_each(erp, &hapd->erp_keys, struct eap_server_erp_key,
+			 list) {
+		if (os_strcmp(erp->keyname_nai, keyname) == 0)
+			return erp;
+	}
+
+	return NULL;
+}
+
+
+static int ieee802_1x_erp_add_key(void *ctx, struct eap_server_erp_key *erp)
+{
+	struct hostapd_data *hapd = ctx;
+
+	dl_list_add(&hapd->erp_keys, &erp->list);
+	return 0;
+}
+
+#endif /* CONFIG_ERP */
+
+
 int ieee802_1x_init(struct hostapd_data *hapd)
 {
 	int i;
 	struct eapol_auth_config conf;
 	struct eapol_auth_cb cb;
 
+	dl_list_init(&hapd->erp_keys);
+
 	os_memset(&conf, 0, sizeof(conf));
 	conf.ctx = hapd;
 	conf.eap_reauth_period = hapd->conf->eap_reauth_period;
@@ -2005,6 +2082,7 @@ int ieee802_1x_init(struct hostapd_data *hapd)
 	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.erp = hapd->conf->eap_server_erp;
 	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;
@@ -2037,6 +2115,10 @@ int ieee802_1x_init(struct hostapd_data *hapd)
 	cb.abort_auth = _ieee802_1x_abort_auth;
 	cb.tx_key = _ieee802_1x_tx_key;
 	cb.eapol_event = ieee802_1x_eapol_event;
+#ifdef CONFIG_ERP
+	cb.erp_get_key = ieee802_1x_erp_get_key;
+	cb.erp_add_key = ieee802_1x_erp_add_key;
+#endif /* CONFIG_ERP */
 
 	hapd->eapol_auth = eapol_auth_init(&conf, &cb);
 	if (hapd->eapol_auth == NULL)
@@ -2070,6 +2152,8 @@ int ieee802_1x_init(struct hostapd_data *hapd)
 
 void ieee802_1x_deinit(struct hostapd_data *hapd)
 {
+	struct eap_server_erp_key *erp;
+
 	eloop_cancel_timeout(ieee802_1x_rekey, hapd, NULL);
 
 	if (hapd->driver != NULL &&
@@ -2078,6 +2162,12 @@ void ieee802_1x_deinit(struct hostapd_data *hapd)
 
 	eapol_auth_deinit(hapd->eapol_auth);
 	hapd->eapol_auth = NULL;
+
+	while ((erp = dl_list_first(&hapd->erp_keys, struct eap_server_erp_key,
+				    list)) != NULL) {
+		dl_list_del(&erp->list);
+		bin_clear_free(erp, sizeof(*erp));
+	}
 }
 
 
diff --git a/src/eap_server/eap.h b/src/eap_server/eap.h
index 395d8955f..9de6cb62f 100644
--- a/src/eap_server/eap.h
+++ b/src/eap_server/eap.h
@@ -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.
@@ -10,6 +10,7 @@
 #define EAP_H
 
 #include "common/defs.h"
+#include "utils/list.h"
 #include "eap_common/eap_defs.h"
 #include "eap_server/eap_methods.h"
 #include "wpabuf.h"
@@ -80,6 +81,17 @@ struct eap_eapol_interface {
 	Boolean aaaTimeout;
 };
 
+struct eap_server_erp_key {
+	struct dl_list list;
+	size_t rRK_len;
+	size_t rIK_len;
+	u8 rRK[ERP_MAX_KEY_LEN];
+	u8 rIK[ERP_MAX_KEY_LEN];
+	u32 recv_seq;
+	u8 cryptosuite;
+	char keyname_nai[];
+};
+
 struct eapol_callbacks {
 	int (*get_eap_user)(void *ctx, const u8 *identity, size_t identity_len,
 			    int phase2, struct eap_user *user);
@@ -87,6 +99,9 @@ struct eapol_callbacks {
 	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_server_erp_key * (*erp_get_key)(void *ctx,
+						   const char *keyname);
+	int (*erp_add_key)(void *ctx, struct eap_server_erp_key *erp);
 };
 
 struct eap_config {
@@ -115,6 +130,7 @@ struct eap_config {
 
 	const u8 *server_id;
 	size_t server_id_len;
+	int erp;
 
 #ifdef CONFIG_TESTING_OPTIONS
 	u32 tls_test_flags;
diff --git a/src/eap_server/eap_i.h b/src/eap_server/eap_i.h
index 9c757d9c8..7d723091f 100644
--- a/src/eap_server/eap_i.h
+++ b/src/eap_server/eap_i.h
@@ -117,7 +117,7 @@ struct eap_sm {
 		EAP_RECEIVED2, EAP_DISCARD2, EAP_SEND_REQUEST2,
 		EAP_AAA_REQUEST, EAP_AAA_RESPONSE, EAP_AAA_IDLE,
 		EAP_TIMEOUT_FAILURE2, EAP_FAILURE2, EAP_SUCCESS2,
-		EAP_INITIATE_REAUTH_START
+		EAP_INITIATE_REAUTH_START, EAP_INITIATE_RECEIVED
 	} EAP_state;
 
 	/* Constants */
@@ -139,6 +139,7 @@ struct eap_sm {
 
 	/* Short-term (not maintained between packets) */
 	Boolean rxResp;
+	Boolean rxInitiate;
 	int respId;
 	EapType respMethod;
 	int respVendor;
@@ -208,6 +209,7 @@ struct eap_sm {
 
 	Boolean initiate_reauth_start_sent;
 	Boolean try_initiate_reauth;
+	int erp;
 
 #ifdef CONFIG_TESTING_OPTIONS
 	u32 tls_test_flags;
diff --git a/src/eap_server/eap_server.c b/src/eap_server/eap_server.c
index b0ec75700..53e32c381 100644
--- a/src/eap_server/eap_server.c
+++ b/src/eap_server/eap_server.c
@@ -15,6 +15,7 @@
 #include "includes.h"
 
 #include "common.h"
+#include "crypto/sha256.h"
 #include "eap_i.h"
 #include "state_machine.h"
 #include "common/wpa_ctrl.h"
@@ -60,6 +61,27 @@ static const char * eap_get_erp_domain(struct eap_sm *sm)
 }
 
 
+#ifdef CONFIG_ERP
+
+static struct eap_server_erp_key * eap_erp_get_key(struct eap_sm *sm,
+						   const char *keyname)
+{
+	if (sm->eapol_cb->erp_get_key)
+		return sm->eapol_cb->erp_get_key(sm->eapol_ctx, keyname);
+	return NULL;
+}
+
+
+static int eap_erp_add_key(struct eap_sm *sm, struct eap_server_erp_key *erp)
+{
+	if (sm->eapol_cb->erp_add_key)
+		return sm->eapol_cb->erp_add_key(sm->eapol_ctx, erp);
+	return -1;
+}
+
+#endif /* CONFIG_ERP */
+
+
 static struct wpabuf * eap_sm_buildInitiateReauthStart(struct eap_sm *sm,
 						       u8 id)
 {
@@ -71,7 +93,7 @@ static struct wpabuf * eap_sm_buildInitiateReauthStart(struct eap_sm *sm,
 	domain = eap_get_erp_domain(sm);
 	if (domain) {
 		domain_len = os_strlen(domain);
-		plen += 2 + domain_len;;
+		plen += 2 + domain_len;
 	}
 
 	msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_ERP_TYPE_REAUTH_START, plen,
@@ -210,7 +232,6 @@ 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;
@@ -387,6 +408,95 @@ SM_STATE(EAP, METHOD_REQUEST)
 }
 
 
+static void eap_server_erp_init(struct eap_sm *sm)
+{
+#ifdef CONFIG_ERP
+	u8 *emsk = NULL;
+	size_t emsk_len;
+	u8 EMSKname[EAP_EMSK_NAME_LEN];
+	u8 len[2];
+	const char *domain;
+	size_t domain_len, nai_buf_len;
+	struct eap_server_erp_key *erp = NULL;
+	int pos;
+
+	domain = eap_get_erp_domain(sm);
+	if (!domain)
+		return;
+
+	domain_len = os_strlen(domain);
+
+	nai_buf_len = 2 * EAP_EMSK_NAME_LEN + 1 + domain_len;
+	if (nai_buf_len > 253) {
+		/*
+		 * keyName-NAI has a maximum length of 253 octet to fit in
+		 * RADIUS attributes.
+		 */
+		wpa_printf(MSG_DEBUG,
+			   "EAP: Too long realm for ERP keyName-NAI maximum length");
+		return;
+	}
+	nai_buf_len++; /* null termination */
+	erp = os_zalloc(sizeof(*erp) + nai_buf_len);
+	if (erp == NULL)
+		goto fail;
+	erp->recv_seq = (u32) -1;
+
+	emsk = sm->m->get_emsk(sm, sm->eap_method_priv, &emsk_len);
+	if (!emsk || emsk_len == 0 || emsk_len > ERP_MAX_KEY_LEN) {
+		wpa_printf(MSG_DEBUG,
+			   "EAP: No suitable EMSK available for ERP");
+		goto fail;
+	}
+
+	wpa_hexdump_key(MSG_DEBUG, "EAP: EMSK", emsk, emsk_len);
+
+	WPA_PUT_BE16(len, 8);
+	if (hmac_sha256_kdf(sm->eap_if.eapSessionId, sm->eap_if.eapSessionIdLen,
+			    "EMSK", len, sizeof(len),
+			    EMSKname, EAP_EMSK_NAME_LEN) < 0) {
+		wpa_printf(MSG_DEBUG, "EAP: Could not derive EMSKname");
+		goto fail;
+	}
+	wpa_hexdump(MSG_DEBUG, "EAP: EMSKname", EMSKname, EAP_EMSK_NAME_LEN);
+
+	pos = wpa_snprintf_hex(erp->keyname_nai, nai_buf_len,
+			       EMSKname, EAP_EMSK_NAME_LEN);
+	erp->keyname_nai[pos] = '@';
+	os_memcpy(&erp->keyname_nai[pos + 1], domain, domain_len);
+
+	WPA_PUT_BE16(len, emsk_len);
+	if (hmac_sha256_kdf(emsk, emsk_len,
+			    "EAP Re-authentication Root Key@ietf.org",
+			    len, sizeof(len), erp->rRK, emsk_len) < 0) {
+		wpa_printf(MSG_DEBUG, "EAP: Could not derive rRK for ERP");
+		goto fail;
+	}
+	erp->rRK_len = emsk_len;
+	wpa_hexdump_key(MSG_DEBUG, "EAP: ERP rRK", erp->rRK, erp->rRK_len);
+
+	if (hmac_sha256_kdf(erp->rRK, erp->rRK_len,
+			    "EAP Re-authentication Integrity Key@ietf.org",
+			    len, sizeof(len), erp->rIK, erp->rRK_len) < 0) {
+		wpa_printf(MSG_DEBUG, "EAP: Could not derive rIK for ERP");
+		goto fail;
+	}
+	erp->rIK_len = erp->rRK_len;
+	wpa_hexdump_key(MSG_DEBUG, "EAP: ERP rIK", erp->rIK, erp->rIK_len);
+
+	if (eap_erp_add_key(sm, erp) == 0) {
+		wpa_printf(MSG_DEBUG, "EAP: Stored ERP keys %s",
+			   erp->keyname_nai);
+		erp = NULL;
+	}
+
+fail:
+	bin_clear_free(emsk, emsk_len);
+	bin_clear_free(erp, sizeof(*erp));
+#endif /* CONFIG_ERP */
+}
+
+
 SM_STATE(EAP, METHOD_RESPONSE)
 {
 	SM_ENTRY(EAP, METHOD_RESPONSE);
@@ -416,6 +526,8 @@ SM_STATE(EAP, METHOD_RESPONSE)
 				    sm->eap_if.eapSessionId,
 				    sm->eap_if.eapSessionIdLen);
 		}
+		if (sm->erp && sm->m->get_emsk && sm->eap_if.eapSessionId)
+			eap_server_erp_init(sm);
 		sm->methodState = METHOD_END;
 	} else {
 		sm->methodState = METHOD_CONTINUE;
@@ -573,12 +685,307 @@ SM_STATE(EAP, INITIATE_REAUTH_START)
 }
 
 
+#ifdef CONFIG_ERP
+
+static void erp_send_finish_reauth(struct eap_sm *sm,
+				   struct eap_server_erp_key *erp, u8 id,
+				   u8 flags, u16 seq, const char *nai)
+{
+	size_t plen;
+	struct wpabuf *msg;
+	u8 hash[SHA256_MAC_LEN];
+	size_t hash_len;
+	u8 seed[4];
+
+	if (erp) {
+		switch (erp->cryptosuite) {
+		case EAP_ERP_CS_HMAC_SHA256_256:
+			hash_len = 32;
+			break;
+		case EAP_ERP_CS_HMAC_SHA256_128:
+			hash_len = 16;
+			break;
+		default:
+			return;
+		}
+	} else
+		hash_len = 0;
+
+	plen = 1 + 2 + 2 + os_strlen(nai);
+	if (hash_len)
+		plen += 1 + hash_len;
+	msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_ERP_TYPE_REAUTH, plen,
+			    EAP_CODE_FINISH, id);
+	if (msg == NULL)
+		return;
+	wpabuf_put_u8(msg, flags);
+	wpabuf_put_be16(msg, seq);
+
+	wpabuf_put_u8(msg, EAP_ERP_TLV_KEYNAME_NAI);
+	wpabuf_put_u8(msg, os_strlen(nai));
+	wpabuf_put_str(msg, nai);
+
+	if (erp) {
+		wpabuf_put_u8(msg, erp->cryptosuite);
+		if (hmac_sha256(erp->rIK, erp->rIK_len,
+				wpabuf_head(msg), wpabuf_len(msg), hash) < 0) {
+			wpabuf_free(msg);
+			return;
+		}
+		wpabuf_put_data(msg, hash, hash_len);
+	}
+
+	wpa_printf(MSG_DEBUG, "EAP: Send EAP-Finish/Re-auth (%s)",
+		   flags & 0x80 ? "failure" : "success");
+
+	sm->lastId = sm->currentId;
+	sm->currentId = id;
+	wpabuf_free(sm->eap_if.eapReqData);
+	sm->eap_if.eapReqData = msg;
+	wpabuf_free(sm->lastReqData);
+	sm->lastReqData = NULL;
+
+	if (flags & 0x80) {
+		sm->eap_if.eapFail = TRUE;
+		wpa_msg(sm->msg_ctx, MSG_INFO, WPA_EVENT_EAP_FAILURE
+			MACSTR, MAC2STR(sm->peer_addr));
+		return;
+	}
+
+	bin_clear_free(sm->eap_if.eapKeyData, sm->eap_if.eapKeyDataLen);
+	sm->eap_if.eapKeyDataLen = 0;
+	sm->eap_if.eapKeyData = os_malloc(erp->rRK_len);
+	if (!sm->eap_if.eapKeyData)
+		return;
+
+	WPA_PUT_BE16(seed, seq);
+	WPA_PUT_BE16(&seed[2], erp->rRK_len);
+	if (hmac_sha256_kdf(erp->rRK, erp->rRK_len,
+			    "Re-authentication Master Session Key@ietf.org",
+			    seed, sizeof(seed),
+			    sm->eap_if.eapKeyData, erp->rRK_len) < 0) {
+		wpa_printf(MSG_DEBUG, "EAP: Could not derive rMSK for ERP");
+		bin_clear_free(sm->eap_if.eapKeyData, erp->rRK_len);
+		sm->eap_if.eapKeyData = NULL;
+		return;
+	}
+	sm->eap_if.eapKeyDataLen = erp->rRK_len;
+	sm->eap_if.eapKeyAvailable = TRUE;
+	wpa_hexdump_key(MSG_DEBUG, "EAP: ERP rMSK",
+			sm->eap_if.eapKeyData, sm->eap_if.eapKeyDataLen);
+	sm->eap_if.eapSuccess = TRUE;
+
+	wpa_msg(sm->msg_ctx, MSG_INFO, WPA_EVENT_EAP_SUCCESS
+		MACSTR, MAC2STR(sm->peer_addr));
+}
+
+
+SM_STATE(EAP, INITIATE_RECEIVED)
+{
+	const u8 *pos, *end, *start, *tlvs, *hdr;
+	const struct eap_hdr *ehdr;
+	size_t len;
+	u8 flags;
+	u16 seq;
+	char nai[254];
+	struct eap_server_erp_key *erp;
+	int max_len;
+	u8 hash[SHA256_MAC_LEN];
+	size_t hash_len;
+	struct erp_tlvs parse;
+	u8 resp_flags = 0x80; /* default to failure; cleared on success */
+
+	SM_ENTRY(EAP, INITIATE_RECEIVED);
+
+	sm->rxInitiate = FALSE;
+
+	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_ERP_TYPE_REAUTH,
+			       sm->eap_if.eapRespData, &len);
+	if (pos == NULL) {
+		wpa_printf(MSG_INFO, "EAP-Initiate: Invalid frame");
+		goto fail;
+	}
+	hdr = wpabuf_head(sm->eap_if.eapRespData);
+	ehdr = wpabuf_head(sm->eap_if.eapRespData);
+
+	wpa_hexdump(MSG_DEBUG, "EAP: EAP-Initiate/Re-Auth", pos, len);
+	if (len < 4) {
+		wpa_printf(MSG_INFO, "EAP: Too short EAP-Initiate/Re-auth");
+		goto fail;
+	}
+	end = pos + len;
+
+	flags = *pos++;
+	seq = WPA_GET_BE16(pos);
+	pos += 2;
+	wpa_printf(MSG_DEBUG, "EAP: Flags=0x%x SEQ=%u", flags, seq);
+	tlvs = pos;
+
+	/*
+	 * Parse TVs/TLVs. Since we do not yet know the length of the
+	 * Authentication Tag, stop parsing if an unknown TV/TLV is seen and
+	 * just try to find the keyName-NAI first so that we can check the
+	 * Authentication Tag.
+	 */
+	if (erp_parse_tlvs(tlvs, end, &parse, 1) < 0)
+		goto fail;
+
+	if (!parse.keyname) {
+		wpa_printf(MSG_DEBUG,
+			   "EAP: No keyName-NAI in EAP-Initiate/Re-auth Packet");
+		goto fail;
+	}
+
+	wpa_hexdump_ascii(MSG_DEBUG, "EAP: EAP-Initiate/Re-auth - keyName-NAI",
+			  parse.keyname, parse.keyname_len);
+	if (parse.keyname_len > 253) {
+		wpa_printf(MSG_DEBUG,
+			   "EAP: Too long keyName-NAI in EAP-Initiate/Re-auth");
+		goto fail;
+	}
+	os_memcpy(nai, parse.keyname, parse.keyname_len);
+	nai[parse.keyname_len] = '\0';
+
+	if (!sm->eap_server) {
+		/*
+		 * In passthrough case, EAP-Initiate/Re-auth replaces
+		 * EAP Identity exchange. Use keyName-NAI as the user identity
+		 * and forward EAP-Initiate/Re-auth to the backend
+		 * authentication server.
+		 */
+		wpa_printf(MSG_DEBUG,
+			   "EAP: Use keyName-NAI as user identity for backend authentication");
+		eap_server_clear_identity(sm);
+		sm->identity = (u8 *) dup_binstr(parse.keyname,
+						 parse.keyname_len);
+		if (!sm->identity)
+			goto fail;
+		sm->identity_len = parse.keyname_len;
+		return;
+	}
+
+	erp = eap_erp_get_key(sm, nai);
+	if (!erp) {
+		wpa_printf(MSG_DEBUG, "EAP: No matching ERP key found for %s",
+			   nai);
+		goto report_error;
+	}
+
+	if (erp->recv_seq != (u32) -1 && erp->recv_seq >= seq) {
+		wpa_printf(MSG_DEBUG,
+			   "EAP: SEQ=%u replayed (already received SEQ=%u)",
+			   seq, erp->recv_seq);
+		goto fail;
+	}
+
+	/* Is there enough room for Cryptosuite and Authentication Tag? */
+	start = parse.keyname + parse.keyname_len;
+	max_len = end - start;
+	if (max_len <
+	    1 + (erp->cryptosuite == EAP_ERP_CS_HMAC_SHA256_256 ? 32 : 16)) {
+		wpa_printf(MSG_DEBUG,
+			   "EAP: Not enough room for Authentication Tag");
+		goto fail;
+	}
+
+	switch (erp->cryptosuite) {
+	case EAP_ERP_CS_HMAC_SHA256_256:
+		if (end[-33] != erp->cryptosuite) {
+			wpa_printf(MSG_DEBUG,
+				   "EAP: Different Cryptosuite used");
+			goto fail;
+		}
+		hash_len = 32;
+		break;
+	case EAP_ERP_CS_HMAC_SHA256_128:
+		if (end[-17] != erp->cryptosuite) {
+			wpa_printf(MSG_DEBUG,
+				   "EAP: Different Cryptosuite used");
+			goto fail;
+		}
+		hash_len = 16;
+		break;
+	default:
+		hash_len = 0;
+		break;
+	}
+
+	if (hash_len) {
+		if (hmac_sha256(erp->rIK, erp->rIK_len, hdr,
+				end - hdr - hash_len, hash) < 0)
+			goto fail;
+		if (os_memcmp(end - hash_len, hash, hash_len) != 0) {
+			wpa_printf(MSG_DEBUG,
+				   "EAP: Authentication Tag mismatch");
+			goto fail;
+		}
+	}
+
+	/* Check if any supported CS results in matching tag */
+	if (!hash_len && max_len >= 1 + 32 &&
+	    end[-33] == EAP_ERP_CS_HMAC_SHA256_256) {
+		if (hmac_sha256(erp->rIK, erp->rIK_len, hdr,
+				end - hdr - 32, hash) < 0)
+			goto fail;
+		if (os_memcmp(end - 32, hash, 32) == 0) {
+			wpa_printf(MSG_DEBUG,
+				   "EAP: Authentication Tag match using HMAC-SHA256-256");
+			hash_len = 32;
+			erp->cryptosuite = EAP_ERP_CS_HMAC_SHA256_256;
+		}
+	}
+
+	if (!hash_len && end[-17] == EAP_ERP_CS_HMAC_SHA256_128) {
+		if (hmac_sha256(erp->rIK, erp->rIK_len, hdr,
+				end - hdr - 16, hash) < 0)
+			goto fail;
+		if (os_memcmp(end - 16, hash, 16) == 0) {
+			wpa_printf(MSG_DEBUG,
+				   "EAP: Authentication Tag match using HMAC-SHA256-128");
+			hash_len = 16;
+			erp->cryptosuite = EAP_ERP_CS_HMAC_SHA256_128;
+		}
+	}
+
+	if (!hash_len) {
+		wpa_printf(MSG_DEBUG,
+			   "EAP: No supported cryptosuite matched Authentication Tag");
+		goto fail;
+	}
+	end -= 1 + hash_len;
+
+	/*
+	 * Parse TVs/TLVs again now that we know the exact part of the buffer
+	 * that contains them.
+	 */
+	wpa_hexdump(MSG_DEBUG, "EAP: EAP-Initiate/Re-Auth TVs/TLVs",
+		    tlvs, end - tlvs);
+	if (erp_parse_tlvs(tlvs, end, &parse, 0) < 0)
+		goto fail;
+
+	wpa_printf(MSG_DEBUG, "EAP: ERP key %s SEQ updated to %u",
+		   erp->keyname_nai, seq);
+	erp->recv_seq = seq;
+	resp_flags &= ~0x80; /* R=0 - success */
+
+report_error:
+	erp_send_finish_reauth(sm, erp, ehdr->identifier, resp_flags, seq, nai);
+	return;
+
+fail:
+	sm->ignore = TRUE;
+}
+
+#endif /* CONFIG_ERP */
+
+
 SM_STATE(EAP, INITIALIZE_PASSTHROUGH)
 {
 	SM_ENTRY(EAP, INITIALIZE_PASSTHROUGH);
 
 	wpabuf_free(sm->eap_if.aaaEapRespData);
 	sm->eap_if.aaaEapRespData = NULL;
+	sm->try_initiate_reauth = FALSE;
 }
 
 
@@ -802,6 +1209,10 @@ SM_STEP(EAP)
 			   sm->respVendor == EAP_VENDOR_IETF &&
 			   sm->respVendorMethod == sm->currentMethod)))
 			SM_ENTER(EAP, INTEGRITY_CHECK);
+#ifdef CONFIG_ERP
+		else if (sm->rxInitiate)
+			SM_ENTER(EAP, INITIATE_RECEIVED);
+#endif /* CONFIG_ERP */
 		else {
 			wpa_printf(MSG_DEBUG, "EAP: RECEIVED->DISCARD: "
 				   "rxResp=%d respId=%d currentId=%d "
@@ -892,12 +1303,20 @@ SM_STEP(EAP)
 			SM_ENTER(EAP, INITIALIZE_PASSTHROUGH);
 		else if (sm->decision == DECISION_INITIATE_REAUTH_START)
 			SM_ENTER(EAP, INITIATE_REAUTH_START);
+#ifdef CONFIG_ERP
+		else if (sm->eap_server && sm->erp && sm->rxInitiate)
+			SM_ENTER(EAP, INITIATE_RECEIVED);
+#endif /* CONFIG_ERP */
 		else
 			SM_ENTER(EAP, PROPOSE_METHOD);
 		break;
 	case EAP_INITIATE_REAUTH_START:
 		SM_ENTER(EAP, SEND_REQUEST);
 		break;
+	case EAP_INITIATE_RECEIVED:
+		if (!sm->eap_server)
+			SM_ENTER(EAP, SELECT_ACTION);
+		break;
 	case EAP_TIMEOUT_FAILURE:
 		break;
 	case EAP_FAILURE:
@@ -1026,6 +1445,7 @@ static void eap_sm_parseEapResp(struct eap_sm *sm, const struct wpabuf *resp)
 
 	/* parse rxResp, respId, respMethod */
 	sm->rxResp = FALSE;
+	sm->rxInitiate = FALSE;
 	sm->respId = -1;
 	sm->respMethod = EAP_TYPE_NONE;
 	sm->respVendor = EAP_VENDOR_IETF;
@@ -1052,6 +1472,8 @@ static void eap_sm_parseEapResp(struct eap_sm *sm, const struct wpabuf *resp)
 
 	if (hdr->code == EAP_CODE_RESPONSE)
 		sm->rxResp = TRUE;
+	else if (hdr->code == EAP_CODE_INITIATE)
+		sm->rxInitiate = TRUE;
 
 	if (plen > sizeof(*hdr)) {
 		u8 *pos = (u8 *) (hdr + 1);
@@ -1069,10 +1491,10 @@ static void eap_sm_parseEapResp(struct eap_sm *sm, const struct wpabuf *resp)
 		}
 	}
 
-	wpa_printf(MSG_DEBUG, "EAP: parseEapResp: rxResp=%d respId=%d "
-		   "respMethod=%u respVendor=%u respVendorMethod=%u",
-		   sm->rxResp, sm->respId, sm->respMethod, sm->respVendor,
-		   sm->respVendorMethod);
+	wpa_printf(MSG_DEBUG,
+		   "EAP: parseEapResp: rxResp=%d rxInitiate=%d respId=%d respMethod=%u respVendor=%u respVendorMethod=%u",
+		   sm->rxResp, sm->rxInitiate, sm->respId, sm->respMethod,
+		   sm->respVendor, sm->respVendorMethod);
 }
 
 
@@ -1430,6 +1852,7 @@ struct eap_sm * eap_server_sm_init(void *eapol_ctx,
 	sm->pbc_in_m1 = conf->pbc_in_m1;
 	sm->server_id = conf->server_id;
 	sm->server_id_len = conf->server_id_len;
+	sm->erp = conf->erp;
 
 #ifdef CONFIG_TESTING_OPTIONS
 	sm->tls_test_flags = conf->tls_test_flags;
diff --git a/src/eapol_auth/eapol_auth_sm.c b/src/eapol_auth/eapol_auth_sm.c
index 088e9d3e2..0df6eb564 100644
--- a/src/eapol_auth/eapol_auth_sm.c
+++ b/src/eapol_auth/eapol_auth_sm.c
@@ -834,6 +834,7 @@ eapol_auth_alloc(struct eapol_authenticator *eapol, const u8 *addr,
 	eap_conf.pbc_in_m1 = eapol->conf.pbc_in_m1;
 	eap_conf.server_id = eapol->conf.server_id;
 	eap_conf.server_id_len = eapol->conf.server_id_len;
+	eap_conf.erp = eapol->conf.erp;
 	sm->eap = eap_server_sm_init(sm, &eapol_cb, &eap_conf);
 	if (sm->eap == NULL) {
 		eapol_auth_free(sm);
@@ -1040,6 +1041,21 @@ static const char * eapol_sm_get_erp_domain(void *ctx)
 }
 
 
+static struct eap_server_erp_key * eapol_sm_erp_get_key(void *ctx,
+							const char *keyname)
+{
+	struct eapol_state_machine *sm = ctx;
+	return sm->eapol->cb.erp_get_key(sm->eapol->conf.ctx, keyname);
+}
+
+
+static int eapol_sm_erp_add_key(void *ctx, struct eap_server_erp_key *erp)
+{
+	struct eapol_state_machine *sm = ctx;
+	return sm->eapol->cb.erp_add_key(sm->eapol->conf.ctx, erp);
+}
+
+
 static struct eapol_callbacks eapol_cb =
 {
 	eapol_sm_get_eap_user,
@@ -1047,6 +1063,8 @@ static struct eapol_callbacks eapol_cb =
 	NULL,
 	eapol_sm_get_erp_send_reauth_start,
 	eapol_sm_get_erp_domain,
+	eapol_sm_erp_get_key,
+	eapol_sm_erp_add_key,
 };
 
 
@@ -1129,6 +1147,7 @@ static int eapol_auth_conf_clone(struct eapol_auth_config *dst,
 		dst->erp_domain = NULL;
 	}
 	dst->erp_send_reauth_start = src->erp_send_reauth_start;
+	dst->erp = src->erp;
 
 	return 0;
 
@@ -1183,6 +1202,8 @@ struct eapol_authenticator * eapol_auth_init(struct eapol_auth_config *conf,
 	eapol->cb.abort_auth = cb->abort_auth;
 	eapol->cb.tx_key = cb->tx_key;
 	eapol->cb.eapol_event = cb->eapol_event;
+	eapol->cb.erp_get_key = cb->erp_get_key;
+	eapol->cb.erp_add_key = cb->erp_add_key;
 
 	/* Acct-Multi-Session-Id should be unique over reboots. If reliable
 	 * clock is not available, this could be replaced with reboot counter,
diff --git a/src/eapol_auth/eapol_auth_sm.h b/src/eapol_auth/eapol_auth_sm.h
index 90194d1f6..ebed19ade 100644
--- a/src/eapol_auth/eapol_auth_sm.h
+++ b/src/eapol_auth/eapol_auth_sm.h
@@ -26,6 +26,7 @@ struct eapol_auth_config {
 	size_t eap_req_id_text_len;
 	int erp_send_reauth_start;
 	char *erp_domain; /* a copy of this will be allocated */
+	int erp; /* Whether ERP is enabled on authentication server */
 	u8 *pac_opaque_encr_key;
 	u8 *eap_fast_a_id;
 	size_t eap_fast_a_id_len;
@@ -47,6 +48,7 @@ struct eapol_auth_config {
 };
 
 struct eap_user;
+struct eap_server_erp_key;
 
 typedef enum {
 	EAPOL_LOGGER_DEBUG, EAPOL_LOGGER_INFO, EAPOL_LOGGER_WARNING
@@ -73,6 +75,9 @@ struct eapol_auth_cb {
 	void (*abort_auth)(void *ctx, void *sta_ctx);
 	void (*tx_key)(void *ctx, void *sta_ctx);
 	void (*eapol_event)(void *ctx, void *sta_ctx, enum eapol_event type);
+	struct eap_server_erp_key * (*erp_get_key)(void *ctx,
+						   const char *keyname);
+	int (*erp_add_key)(void *ctx, struct eap_server_erp_key *erp);
 };
 
 
diff --git a/src/radius/radius_server.c b/src/radius/radius_server.c
index 54b258993..d9f2df655 100644
--- a/src/radius/radius_server.c
+++ b/src/radius/radius_server.c
@@ -251,6 +251,20 @@ struct radius_server_data {
 	 */
 	const char *server_id;
 
+	/**
+	 * erp - Whether EAP Re-authentication Protocol (ERP) is enabled
+	 *
+	 * This controls whether the authentication server derives ERP key
+	 * hierarchy (rRK and rIK) from full EAP authentication and allows
+	 * these keys to be used to perform ERP to derive rMSK instead of full
+	 * EAP authentication to derive MSK.
+	 */
+	int erp;
+
+	const char *erp_domain;
+
+	struct dl_list erp_keys; /* struct eap_server_erp_key */
+
 	/**
 	 * wps - Wi-Fi Protected Setup context
 	 *
@@ -673,6 +687,7 @@ radius_server_get_new_session(struct radius_server_data *data,
 	eap_conf.pwd_group = data->pwd_group;
 	eap_conf.server_id = (const u8 *) data->server_id;
 	eap_conf.server_id_len = os_strlen(data->server_id);
+	eap_conf.erp = data->erp;
 	radius_server_testing_options(sess, &eap_conf);
 	sess->eap = eap_server_sm_init(sess, &radius_server_eapol_cb,
 				       &eap_conf);
@@ -1687,6 +1702,7 @@ radius_server_init(struct radius_server_conf *conf)
 	if (data == NULL)
 		return NULL;
 
+	dl_list_init(&data->erp_keys);
 	os_get_reltime(&data->start_time);
 	data->conf_ctx = conf->conf_ctx;
 	data->eap_sim_db_priv = conf->eap_sim_db_priv;
@@ -1725,6 +1741,8 @@ radius_server_init(struct radius_server_conf *conf)
 			data->eap_req_id_text_len = conf->eap_req_id_text_len;
 		}
 	}
+	data->erp = conf->erp;
+	data->erp_domain = conf->erp_domain;
 
 	if (conf->subscr_remediation_url) {
 		data->subscr_remediation_url =
@@ -1807,6 +1825,8 @@ radius_server_init(struct radius_server_conf *conf)
  */
 void radius_server_deinit(struct radius_server_data *data)
 {
+	struct eap_server_erp_key *erp;
+
 	if (data == NULL)
 		return;
 
@@ -1836,6 +1856,12 @@ void radius_server_deinit(struct radius_server_data *data)
 		sqlite3_close(data->db);
 #endif /* CONFIG_SQLITE */
 
+	while ((erp = dl_list_first(&data->erp_keys, struct eap_server_erp_key,
+				    list)) != NULL) {
+		dl_list_del(&erp->list);
+		bin_clear_free(erp, sizeof(*erp));
+	}
+
 	os_free(data);
 }
 
@@ -2017,13 +2043,57 @@ static void radius_server_log_msg(void *ctx, const char *msg)
 }
 
 
+#ifdef CONFIG_ERP
+
+static const char * radius_server_get_erp_domain(void *ctx)
+{
+	struct radius_session *sess = ctx;
+	struct radius_server_data *data = sess->server;
+
+	return data->erp_domain;
+}
+
+
+static struct eap_server_erp_key *
+radius_server_erp_get_key(void *ctx, const char *keyname)
+{
+	struct radius_session *sess = ctx;
+	struct radius_server_data *data = sess->server;
+	struct eap_server_erp_key *erp;
+
+	dl_list_for_each(erp, &data->erp_keys, struct eap_server_erp_key,
+			 list) {
+		if (os_strcmp(erp->keyname_nai, keyname) == 0)
+			return erp;
+	}
+
+	return NULL;
+}
+
+
+static int radius_server_erp_add_key(void *ctx, struct eap_server_erp_key *erp)
+{
+	struct radius_session *sess = ctx;
+	struct radius_server_data *data = sess->server;
+
+	dl_list_add(&data->erp_keys, &erp->list);
+	return 0;
+}
+
+#endif /* CONFIG_ERP */
+
+
 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,
+#ifdef CONFIG_ERP
+	.get_erp_send_reauth_start = NULL,
+	.get_erp_domain = radius_server_get_erp_domain,
+	.erp_get_key = radius_server_erp_get_key,
+	.erp_add_key = radius_server_erp_add_key,
+#endif /* CONFIG_ERP */
 };
 
 
diff --git a/src/radius/radius_server.h b/src/radius/radius_server.h
index 46ac3127e..1b8967c26 100644
--- a/src/radius/radius_server.h
+++ b/src/radius/radius_server.h
@@ -158,6 +158,18 @@ struct radius_server_conf {
 	 */
 	const char *server_id;
 
+	/**
+	 * erp - Whether EAP Re-authentication Protocol (ERP) is enabled
+	 *
+	 * This controls whether the authentication server derives ERP key
+	 * hierarchy (rRK and rIK) from full EAP authentication and allows
+	 * these keys to be used to perform ERP to derive rMSK instead of full
+	 * EAP authentication to derive MSK.
+	 */
+	int erp;
+
+	const char *erp_domain;
+
 	/**
 	 * wps - Wi-Fi Protected Setup context
 	 *