src/eap_peer/eap_ikev2.c - third_party/hostap - Git at Google

 /*
  * EAP-IKEv2 peer (RFC 5106)
  * Copyright (c) 2007-2014, Jouni Malinen <j@w1.fi>
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
  */

 #include "includes.h"

 #include "common.h"
 #include "eap_i.h"
 #include "eap_common/eap_ikev2_common.h"
 #include "ikev2.h"


 struct eap_ikev2_data {
 	struct ikev2_responder_data ikev2;
 	enum { WAIT_START, PROC_MSG, WAIT_FRAG_ACK, DONE, FAIL } state;
 	struct wpabuf *in_buf;
 	struct wpabuf *out_buf;
 	size_t out_used;
 	size_t fragment_size;
 	int keys_ready;
 	u8 keymat[EAP_MSK_LEN + EAP_EMSK_LEN];
 	int keymat_ok;
 };


 static const char * eap_ikev2_state_txt(int state)
 {
 	switch (state) {
 	case WAIT_START:
 		return "WAIT_START";
 	case PROC_MSG:
 		return "PROC_MSG";
 	case WAIT_FRAG_ACK:
 		return "WAIT_FRAG_ACK";
 	case DONE:
 		return "DONE";
 	case FAIL:
 		return "FAIL";
 	default:
 		return "?";
 	}
 }


 static void eap_ikev2_state(struct eap_ikev2_data *data, int state)
 {
 	wpa_printf(MSG_DEBUG, "EAP-IKEV2: %s -> %s",
 		   eap_ikev2_state_txt(data->state),
 		   eap_ikev2_state_txt(state));
 	data->state = state;
 }


 static void * eap_ikev2_init(struct eap_sm *sm)
 {
 	struct eap_ikev2_data *data;
 	const u8 *identity, *password;
 	size_t identity_len, password_len;
 	int fragment_size;

 	identity = eap_get_config_identity(sm, &identity_len);
 	if (identity == NULL) {
 		wpa_printf(MSG_INFO, "EAP-IKEV2: No identity available");
 		return NULL;
 	}

 	data = os_zalloc(sizeof(*data));
 	if (data == NULL)
 		return NULL;
 	data->state = WAIT_START;
 	fragment_size = eap_get_config_fragment_size(sm);
 	if (fragment_size <= 0)
 		data->fragment_size = IKEV2_FRAGMENT_SIZE;
 	else
 		data->fragment_size = fragment_size;
 	data->ikev2.state = SA_INIT;
 	data->ikev2.peer_auth = PEER_AUTH_SECRET;
 	data->ikev2.key_pad = (u8 *) os_strdup("Key Pad for EAP-IKEv2");
 	if (data->ikev2.key_pad == NULL)
 		goto failed;
 	data->ikev2.key_pad_len = 21;
 	data->ikev2.IDr = os_malloc(identity_len);
 	if (data->ikev2.IDr == NULL)
 		goto failed;
 	os_memcpy(data->ikev2.IDr, identity, identity_len);
 	data->ikev2.IDr_len = identity_len;

 	password = eap_get_config_password(sm, &password_len);
 	if (password) {
 		data->ikev2.shared_secret = os_malloc(password_len);
 		if (data->ikev2.shared_secret == NULL)
 			goto failed;
 		os_memcpy(data->ikev2.shared_secret, password, password_len);
 		data->ikev2.shared_secret_len = password_len;
 	}

 	return data;

 failed:
 	ikev2_responder_deinit(&data->ikev2);
 	os_free(data);
 	return NULL;
 }


 static void eap_ikev2_deinit(struct eap_sm *sm, void *priv)
 {
 	struct eap_ikev2_data *data = priv;
 	wpabuf_free(data->in_buf);
 	wpabuf_free(data->out_buf);
 	ikev2_responder_deinit(&data->ikev2);
 	bin_clear_free(data, sizeof(*data));
 }


 static int eap_ikev2_peer_keymat(struct eap_ikev2_data *data)
 {
 	if (eap_ikev2_derive_keymat(
 		    data->ikev2.proposal.prf, &data->ikev2.keys,
 		    data->ikev2.i_nonce, data->ikev2.i_nonce_len,
 		    data->ikev2.r_nonce, data->ikev2.r_nonce_len,
 		    data->keymat) < 0) {
 		wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to "
 			   "derive key material");
 		return -1;
 	}
 	data->keymat_ok = 1;
 	return 0;
 }


 static struct wpabuf * eap_ikev2_build_msg(struct eap_ikev2_data *data,
 					   struct eap_method_ret *ret, u8 id)
 {
 	struct wpabuf *resp;
 	u8 flags;
 	size_t send_len, plen, icv_len = 0;

 	ret->ignore = FALSE;
 	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Generating Response");
 	ret->allowNotifications = TRUE;

 	flags = 0;
 	send_len = wpabuf_len(data->out_buf) - data->out_used;
 	if (1 + send_len > data->fragment_size) {
 		send_len = data->fragment_size - 1;
 		flags |= IKEV2_FLAGS_MORE_FRAGMENTS;
 		if (data->out_used == 0) {
 			flags |= IKEV2_FLAGS_LENGTH_INCLUDED;
 			send_len -= 4;
 		}
 	}

 	plen = 1 + send_len;
 	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
 		plen += 4;
 	if (data->keys_ready) {
 		const struct ikev2_integ_alg *integ;
 		wpa_printf(MSG_DEBUG, "EAP-IKEV2: Add Integrity Checksum "
 			   "Data");
 		flags |= IKEV2_FLAGS_ICV_INCLUDED;
 		integ = ikev2_get_integ(data->ikev2.proposal.integ);
 		if (integ == NULL) {
 			wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unknown INTEG "
 				   "transform / cannot generate ICV");
 			return NULL;
 		}
 		icv_len = integ->hash_len;

 		plen += icv_len;
 	}
 	resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, plen,
 			     EAP_CODE_RESPONSE, id);
 	if (resp == NULL)
 		return NULL;

 	wpabuf_put_u8(resp, flags); /* Flags */
 	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
 		wpabuf_put_be32(resp, wpabuf_len(data->out_buf));

 	wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
 			send_len);
 	data->out_used += send_len;

 	if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
 		const u8 *msg = wpabuf_head(resp);
 		size_t len = wpabuf_len(resp);
 		ikev2_integ_hash(data->ikev2.proposal.integ,
 				 data->ikev2.keys.SK_ar,
 				 data->ikev2.keys.SK_integ_len,
 				 msg, len, wpabuf_put(resp, icv_len));
 	}

 	ret->methodState = METHOD_MAY_CONT;
 	ret->decision = DECISION_FAIL;

 	if (data->out_used == wpabuf_len(data->out_buf)) {
 		wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
 			   "(message sent completely)",
 			   (unsigned long) send_len);
 		wpabuf_free(data->out_buf);
 		data->out_buf = NULL;
 		data->out_used = 0;
 		switch (data->ikev2.state) {
 		case SA_AUTH:
 			/* SA_INIT was sent out, so message have to be
 			 * integrity protected from now on. */
 			data->keys_ready = 1;
 			break;
 		case IKEV2_DONE:
 			ret->methodState = METHOD_DONE;
 			if (data->state == FAIL)
 				break;
 			ret->decision = DECISION_COND_SUCC;
 			wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication "
 				   "completed successfully");
 			if (eap_ikev2_peer_keymat(data))
 				break;
 			eap_ikev2_state(data, DONE);
 			break;
 		case IKEV2_FAILED:
 			wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication "
 				   "failed");
 			ret->methodState = METHOD_DONE;
 			ret->decision = DECISION_FAIL;
 			break;
 		default:
 			break;
 		}
 	} else {
 		wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
 			   "(%lu more to send)", (unsigned long) send_len,
 			   (unsigned long) wpabuf_len(data->out_buf) -
 			   data->out_used);
 		eap_ikev2_state(data, WAIT_FRAG_ACK);
 	}

 	return resp;
 }


 static int eap_ikev2_process_icv(struct eap_ikev2_data *data,
 				 const struct wpabuf *reqData,
 				 u8 flags, const u8 *pos, const u8 **end,
 				 int frag_ack)
 {
 	if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
 		int icv_len = eap_ikev2_validate_icv(
 			data->ikev2.proposal.integ, &data->ikev2.keys, 1,
 			reqData, pos, *end);
 		if (icv_len < 0)
 			return -1;
 		/* Hide Integrity Checksum Data from further processing */
 		*end -= icv_len;
 	} else if (data->keys_ready && !frag_ack) {
 		wpa_printf(MSG_INFO, "EAP-IKEV2: The message should have "
 			   "included integrity checksum");
 		return -1;
 	}

 	return 0;
 }


 static int eap_ikev2_process_cont(struct eap_ikev2_data *data,
 				  const u8 *buf, size_t len)
 {
 	/* Process continuation of a pending message */
 	if (len > wpabuf_tailroom(data->in_buf)) {
 		wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment overflow");
 		eap_ikev2_state(data, FAIL);
 		return -1;
 	}

 	wpabuf_put_data(data->in_buf, buf, len);
 	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes, waiting "
 		   "for %lu bytes more", (unsigned long) len,
 		   (unsigned long) wpabuf_tailroom(data->in_buf));

 	return 0;
 }


 static struct wpabuf * eap_ikev2_process_fragment(struct eap_ikev2_data *data,
 						  struct eap_method_ret *ret,
 						  u8 id, u8 flags,
 						  u32 message_length,
 						  const u8 *buf, size_t len)
 {
 	/* Process a fragment that is not the last one of the message */
 	if (data->in_buf == NULL && !(flags & IKEV2_FLAGS_LENGTH_INCLUDED)) {
 		wpa_printf(MSG_DEBUG, "EAP-IKEV2: No Message Length field in "
 			   "a fragmented packet");
 		ret->ignore = TRUE;
 		return NULL;
 	}

 	if (data->in_buf == NULL) {
 		/* First fragment of the message */
 		if (message_length > 50000) {
 			/* Limit maximum memory allocation */
 			wpa_printf(MSG_DEBUG,
 				   "EAP-IKEV2: Ignore too long message");
 			ret->ignore = TRUE;
 			return NULL;
 		}
 		data->in_buf = wpabuf_alloc(message_length);
 		if (data->in_buf == NULL) {
 			wpa_printf(MSG_DEBUG, "EAP-IKEV2: No memory for "
 				   "message");
 			ret->ignore = TRUE;
 			return NULL;
 		}
 		wpabuf_put_data(data->in_buf, buf, len);
 		wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes in first "
 			   "fragment, waiting for %lu bytes more",
 			   (unsigned long) len,
 			   (unsigned long) wpabuf_tailroom(data->in_buf));
 	}

 	ret->ignore = FALSE;
 	return eap_ikev2_build_frag_ack(id, EAP_CODE_RESPONSE);
 }


 static struct wpabuf * eap_ikev2_process(struct eap_sm *sm, void *priv,
 					 struct eap_method_ret *ret,
 					 const struct wpabuf *reqData)
 {
 	struct eap_ikev2_data *data = priv;
 	const u8 *start, *pos, *end;
 	size_t len;
 	u8 flags, id;
 	u32 message_length = 0;
 	struct wpabuf tmpbuf;

 	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, reqData, &len);
 	if (pos == NULL) {
 		ret->ignore = TRUE;
 		return NULL;
 	}

 	id = eap_get_id(reqData);

 	start = pos;
 	end = start + len;

 	if (len == 0)
 		flags = 0; /* fragment ack */
 	else
 		flags = *pos++;

 	if (eap_ikev2_process_icv(data, reqData, flags, pos, &end,
 				  data->state == WAIT_FRAG_ACK && len == 0) < 0)
 	{
 		ret->ignore = TRUE;
 		return NULL;
 	}

 	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED) {
 		if (end - pos < 4) {
 			wpa_printf(MSG_DEBUG, "EAP-IKEV2: Message underflow");
 			ret->ignore = TRUE;
 			return NULL;
 		}
 		message_length = WPA_GET_BE32(pos);
 		pos += 4;

 		if (message_length < (u32) (end - pos)) {
 			wpa_printf(MSG_DEBUG, "EAP-IKEV2: Invalid Message "
 				   "Length (%d; %ld remaining in this msg)",
 				   message_length, (long) (end - pos));
 			ret->ignore = TRUE;
 			return NULL;
 		}
 	}

 	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received packet: Flags 0x%x "
 		   "Message Length %u", flags, message_length);

 	if (data->state == WAIT_FRAG_ACK) {
 		if (len != 0) {
 			wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unexpected payload "
 				   "in WAIT_FRAG_ACK state");
 			ret->ignore = TRUE;
 			return NULL;
 		}
 		wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment acknowledged");
 		eap_ikev2_state(data, PROC_MSG);
 		return eap_ikev2_build_msg(data, ret, id);
 	}

 	if (data->in_buf && eap_ikev2_process_cont(data, pos, end - pos) < 0) {
 		ret->ignore = TRUE;
 		return NULL;
 	}

 	if (flags & IKEV2_FLAGS_MORE_FRAGMENTS) {
 		return eap_ikev2_process_fragment(data, ret, id, flags,
 						  message_length, pos,
 						  end - pos);
 	}

 	if (data->in_buf == NULL) {
 		/* Wrap unfragmented messages as wpabuf without extra copy */
 		wpabuf_set(&tmpbuf, pos, end - pos);
 		data->in_buf = &tmpbuf;
 	}

 	if (ikev2_responder_process(&data->ikev2, data->in_buf) < 0) {
 		if (data->in_buf == &tmpbuf)
 			data->in_buf = NULL;
 		eap_ikev2_state(data, FAIL);
 		return NULL;
 	}

 	if (data->in_buf != &tmpbuf)
 		wpabuf_free(data->in_buf);
 	data->in_buf = NULL;

 	if (data->out_buf == NULL) {
 		data->out_buf = ikev2_responder_build(&data->ikev2);
 		if (data->out_buf == NULL) {
 			wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to generate "
 				   "IKEv2 message");
 			return NULL;
 		}
 		data->out_used = 0;
 	}

 	eap_ikev2_state(data, PROC_MSG);
 	return eap_ikev2_build_msg(data, ret, id);
 }


 static Boolean eap_ikev2_isKeyAvailable(struct eap_sm *sm, void *priv)
 {
 	struct eap_ikev2_data *data = priv;
 	return data->state == DONE && data->keymat_ok;
 }


 static u8 * eap_ikev2_getKey(struct eap_sm *sm, void *priv, size_t *len)
 {
 	struct eap_ikev2_data *data = priv;
 	u8 *key;

 	if (data->state != DONE || !data->keymat_ok)
 		return NULL;

 	key = os_malloc(EAP_MSK_LEN);
 	if (key) {
 		os_memcpy(key, data->keymat, EAP_MSK_LEN);
 		*len = EAP_MSK_LEN;
 	}

 	return key;
 }


 static u8 * eap_ikev2_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
 {
 	struct eap_ikev2_data *data = priv;
 	u8 *key;

 	if (data->state != DONE || !data->keymat_ok)
 		return NULL;

 	key = os_malloc(EAP_EMSK_LEN);
 	if (key) {
 		os_memcpy(key, data->keymat + EAP_MSK_LEN, EAP_EMSK_LEN);
 		*len = EAP_EMSK_LEN;
 	}

 	return key;
 }


 static u8 * eap_ikev2_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
 {
 	struct eap_ikev2_data *data = priv;
 	u8 *sid;
 	size_t sid_len;
 	size_t offset;

 	if (data->state != DONE || !data->keymat_ok)
 		return NULL;

 	sid_len = 1 + data->ikev2.i_nonce_len + data->ikev2.r_nonce_len;
 	sid = os_malloc(sid_len);
 	if (sid) {
 		offset = 0;
 		sid[offset] = EAP_TYPE_IKEV2;
 		offset++;
 		os_memcpy(sid + offset, data->ikev2.i_nonce,
 			  data->ikev2.i_nonce_len);
 		offset += data->ikev2.i_nonce_len;
 		os_memcpy(sid + offset, data->ikev2.r_nonce,
 			  data->ikev2.r_nonce_len);
 		*len = sid_len;
 		wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Derived Session-Id",
 			    sid, sid_len);
 	}

 	return sid;
 }


 int eap_peer_ikev2_register(void)
 {
 	struct eap_method *eap;
 	int ret;

 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 				    EAP_VENDOR_IETF, EAP_TYPE_IKEV2,
 				    "IKEV2");
 	if (eap == NULL)
 		return -1;

 	eap->init = eap_ikev2_init;
 	eap->deinit = eap_ikev2_deinit;
 	eap->process = eap_ikev2_process;
 	eap->isKeyAvailable = eap_ikev2_isKeyAvailable;
 	eap->getKey = eap_ikev2_getKey;
 	eap->get_emsk = eap_ikev2_get_emsk;
 	eap->getSessionId = eap_ikev2_get_session_id;

 	ret = eap_peer_method_register(eap);
 	if (ret)
 		eap_peer_method_free(eap);
 	return ret;
 }
	/*
	* EAP-IKEv2 peer (RFC 5106)
	* Copyright (c) 2007-2014, Jouni Malinen <j@w1.fi>
	*
	* This software may be distributed under the terms of the BSD license.
	* See README for more details.
	*/

	#include "includes.h"

	#include "common.h"
	#include "eap_i.h"
	#include "eap_common/eap_ikev2_common.h"
	#include "ikev2.h"


	struct eap_ikev2_data {
	struct ikev2_responder_data ikev2;
	enum { WAIT_START, PROC_MSG, WAIT_FRAG_ACK, DONE, FAIL } state;
	struct wpabuf *in_buf;
	struct wpabuf *out_buf;
	size_t out_used;
	size_t fragment_size;
	int keys_ready;
	u8 keymat[EAP_MSK_LEN + EAP_EMSK_LEN];
	int keymat_ok;
	};


	static const char * eap_ikev2_state_txt(int state)
	{
	switch (state) {
	case WAIT_START:
	return "WAIT_START";
	case PROC_MSG:
	return "PROC_MSG";
	case WAIT_FRAG_ACK:
	return "WAIT_FRAG_ACK";
	case DONE:
	return "DONE";
	case FAIL:
	return "FAIL";
	default:
	return "?";
	}
	}


	static void eap_ikev2_state(struct eap_ikev2_data *data, int state)
	{
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: %s -> %s",
	eap_ikev2_state_txt(data->state),
	eap_ikev2_state_txt(state));
	data->state = state;
	}


	static void * eap_ikev2_init(struct eap_sm *sm)
	{
	struct eap_ikev2_data *data;
	const u8 identity, password;
	size_t identity_len, password_len;
	int fragment_size;

	identity = eap_get_config_identity(sm, &identity_len);
	if (identity == NULL) {
	wpa_printf(MSG_INFO, "EAP-IKEV2: No identity available");
	return NULL;
	}

	data = os_zalloc(sizeof(*data));
	if (data == NULL)
	return NULL;
	data->state = WAIT_START;
	fragment_size = eap_get_config_fragment_size(sm);
	if (fragment_size <= 0)
	data->fragment_size = IKEV2_FRAGMENT_SIZE;
	else
	data->fragment_size = fragment_size;
	data->ikev2.state = SA_INIT;
	data->ikev2.peer_auth = PEER_AUTH_SECRET;
	data->ikev2.key_pad = (u8 *) os_strdup("Key Pad for EAP-IKEv2");
	if (data->ikev2.key_pad == NULL)
	goto failed;
	data->ikev2.key_pad_len = 21;
	data->ikev2.IDr = os_malloc(identity_len);
	if (data->ikev2.IDr == NULL)
	goto failed;
	os_memcpy(data->ikev2.IDr, identity, identity_len);
	data->ikev2.IDr_len = identity_len;

	password = eap_get_config_password(sm, &password_len);
	if (password) {
	data->ikev2.shared_secret = os_malloc(password_len);
	if (data->ikev2.shared_secret == NULL)
	goto failed;
	os_memcpy(data->ikev2.shared_secret, password, password_len);
	data->ikev2.shared_secret_len = password_len;
	}

	return data;

	failed:
	ikev2_responder_deinit(&data->ikev2);
	os_free(data);
	return NULL;
	}


	static void eap_ikev2_deinit(struct eap_sm sm, void priv)
	{
	struct eap_ikev2_data *data = priv;
	wpabuf_free(data->in_buf);
	wpabuf_free(data->out_buf);
	ikev2_responder_deinit(&data->ikev2);
	bin_clear_free(data, sizeof(*data));
	}


	static int eap_ikev2_peer_keymat(struct eap_ikev2_data *data)
	{
	if (eap_ikev2_derive_keymat(
	data->ikev2.proposal.prf, &data->ikev2.keys,
	data->ikev2.i_nonce, data->ikev2.i_nonce_len,
	data->ikev2.r_nonce, data->ikev2.r_nonce_len,
	data->keymat) < 0) {
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to "
	"derive key material");
	return -1;
	}
	data->keymat_ok = 1;
	return 0;
	}


	static struct wpabuf * eap_ikev2_build_msg(struct eap_ikev2_data *data,
	struct eap_method_ret *ret, u8 id)
	{
	struct wpabuf *resp;
	u8 flags;
	size_t send_len, plen, icv_len = 0;

	ret->ignore = FALSE;
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Generating Response");
	ret->allowNotifications = TRUE;

	flags = 0;
	send_len = wpabuf_len(data->out_buf) - data->out_used;
	if (1 + send_len > data->fragment_size) {
	send_len = data->fragment_size - 1;
	flags \|= IKEV2_FLAGS_MORE_FRAGMENTS;
	if (data->out_used == 0) {
	flags \|= IKEV2_FLAGS_LENGTH_INCLUDED;
	send_len -= 4;
	}
	}

	plen = 1 + send_len;
	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
	plen += 4;
	if (data->keys_ready) {
	const struct ikev2_integ_alg *integ;
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Add Integrity Checksum "
	"Data");
	flags \|= IKEV2_FLAGS_ICV_INCLUDED;
	integ = ikev2_get_integ(data->ikev2.proposal.integ);
	if (integ == NULL) {
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unknown INTEG "
	"transform / cannot generate ICV");
	return NULL;
	}
	icv_len = integ->hash_len;

	plen += icv_len;
	}
	resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, plen,
	EAP_CODE_RESPONSE, id);
	if (resp == NULL)
	return NULL;

	wpabuf_put_u8(resp, flags); /* Flags */
	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
	wpabuf_put_be32(resp, wpabuf_len(data->out_buf));

	wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
	send_len);
	data->out_used += send_len;

	if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
	const u8 *msg = wpabuf_head(resp);
	size_t len = wpabuf_len(resp);
	ikev2_integ_hash(data->ikev2.proposal.integ,
	data->ikev2.keys.SK_ar,
	data->ikev2.keys.SK_integ_len,
	msg, len, wpabuf_put(resp, icv_len));
	}

	ret->methodState = METHOD_MAY_CONT;
	ret->decision = DECISION_FAIL;

	if (data->out_used == wpabuf_len(data->out_buf)) {
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
	"(message sent completely)",
	(unsigned long) send_len);
	wpabuf_free(data->out_buf);
	data->out_buf = NULL;
	data->out_used = 0;
	switch (data->ikev2.state) {
	case SA_AUTH:
	/* SA_INIT was sent out, so message have to be
	* integrity protected from now on. */
	data->keys_ready = 1;
	break;
	case IKEV2_DONE:
	ret->methodState = METHOD_DONE;
	if (data->state == FAIL)
	break;
	ret->decision = DECISION_COND_SUCC;
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication "
	"completed successfully");
	if (eap_ikev2_peer_keymat(data))
	break;
	eap_ikev2_state(data, DONE);
	break;
	case IKEV2_FAILED:
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication "
	"failed");
	ret->methodState = METHOD_DONE;
	ret->decision = DECISION_FAIL;
	break;
	default:
	break;
	}
	} else {
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
	"(%lu more to send)", (unsigned long) send_len,
	(unsigned long) wpabuf_len(data->out_buf) -
	data->out_used);
	eap_ikev2_state(data, WAIT_FRAG_ACK);
	}

	return resp;
	}


	static int eap_ikev2_process_icv(struct eap_ikev2_data *data,
	const struct wpabuf *reqData,
	u8 flags, const u8 pos, const u8 *end,
	int frag_ack)
	{
	if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
	int icv_len = eap_ikev2_validate_icv(
	data->ikev2.proposal.integ, &data->ikev2.keys, 1,
	reqData, pos, *end);
	if (icv_len < 0)
	return -1;
	/* Hide Integrity Checksum Data from further processing */
	*end -= icv_len;
	} else if (data->keys_ready && !frag_ack) {
	wpa_printf(MSG_INFO, "EAP-IKEV2: The message should have "
	"included integrity checksum");
	return -1;
	}

	return 0;
	}


	static int eap_ikev2_process_cont(struct eap_ikev2_data *data,
	const u8 *buf, size_t len)
	{
	/* Process continuation of a pending message */
	if (len > wpabuf_tailroom(data->in_buf)) {
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment overflow");
	eap_ikev2_state(data, FAIL);
	return -1;
	}

	wpabuf_put_data(data->in_buf, buf, len);
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes, waiting "
	"for %lu bytes more", (unsigned long) len,
	(unsigned long) wpabuf_tailroom(data->in_buf));

	return 0;
	}


	static struct wpabuf * eap_ikev2_process_fragment(struct eap_ikev2_data *data,
	struct eap_method_ret *ret,
	u8 id, u8 flags,
	u32 message_length,
	const u8 *buf, size_t len)
	{
	/* Process a fragment that is not the last one of the message */
	if (data->in_buf == NULL && !(flags & IKEV2_FLAGS_LENGTH_INCLUDED)) {
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: No Message Length field in "
	"a fragmented packet");
	ret->ignore = TRUE;
	return NULL;
	}

	if (data->in_buf == NULL) {
	/* First fragment of the message */
	if (message_length > 50000) {
	/* Limit maximum memory allocation */
	wpa_printf(MSG_DEBUG,
	"EAP-IKEV2: Ignore too long message");
	ret->ignore = TRUE;
	return NULL;
	}
	data->in_buf = wpabuf_alloc(message_length);
	if (data->in_buf == NULL) {
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: No memory for "
	"message");
	ret->ignore = TRUE;
	return NULL;
	}
	wpabuf_put_data(data->in_buf, buf, len);
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes in first "
	"fragment, waiting for %lu bytes more",
	(unsigned long) len,
	(unsigned long) wpabuf_tailroom(data->in_buf));
	}

	ret->ignore = FALSE;
	return eap_ikev2_build_frag_ack(id, EAP_CODE_RESPONSE);
	}


	static struct wpabuf * eap_ikev2_process(struct eap_sm sm, void priv,
	struct eap_method_ret *ret,
	const struct wpabuf *reqData)
	{
	struct eap_ikev2_data *data = priv;
	const u8 start, pos, *end;
	size_t len;
	u8 flags, id;
	u32 message_length = 0;
	struct wpabuf tmpbuf;

	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, reqData, &len);
	if (pos == NULL) {
	ret->ignore = TRUE;
	return NULL;
	}

	id = eap_get_id(reqData);

	start = pos;
	end = start + len;

	if (len == 0)
	flags = 0; /* fragment ack */
	else
	flags = *pos++;

	if (eap_ikev2_process_icv(data, reqData, flags, pos, &end,
	data->state == WAIT_FRAG_ACK && len == 0) < 0)
	{
	ret->ignore = TRUE;
	return NULL;
	}

	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED) {
	if (end - pos < 4) {
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Message underflow");
	ret->ignore = TRUE;
	return NULL;
	}
	message_length = WPA_GET_BE32(pos);
	pos += 4;

	if (message_length < (u32) (end - pos)) {
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Invalid Message "
	"Length (%d; %ld remaining in this msg)",
	message_length, (long) (end - pos));
	ret->ignore = TRUE;
	return NULL;
	}
	}

	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received packet: Flags 0x%x "
	"Message Length %u", flags, message_length);

	if (data->state == WAIT_FRAG_ACK) {
	if (len != 0) {
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unexpected payload "
	"in WAIT_FRAG_ACK state");
	ret->ignore = TRUE;
	return NULL;
	}
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment acknowledged");
	eap_ikev2_state(data, PROC_MSG);
	return eap_ikev2_build_msg(data, ret, id);
	}

	if (data->in_buf && eap_ikev2_process_cont(data, pos, end - pos) < 0) {
	ret->ignore = TRUE;
	return NULL;
	}

	if (flags & IKEV2_FLAGS_MORE_FRAGMENTS) {
	return eap_ikev2_process_fragment(data, ret, id, flags,
	message_length, pos,
	end - pos);
	}

	if (data->in_buf == NULL) {
	/* Wrap unfragmented messages as wpabuf without extra copy */
	wpabuf_set(&tmpbuf, pos, end - pos);
	data->in_buf = &tmpbuf;
	}

	if (ikev2_responder_process(&data->ikev2, data->in_buf) < 0) {
	if (data->in_buf == &tmpbuf)
	data->in_buf = NULL;
	eap_ikev2_state(data, FAIL);
	return NULL;
	}

	if (data->in_buf != &tmpbuf)
	wpabuf_free(data->in_buf);
	data->in_buf = NULL;

	if (data->out_buf == NULL) {
	data->out_buf = ikev2_responder_build(&data->ikev2);
	if (data->out_buf == NULL) {
	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to generate "
	"IKEv2 message");
	return NULL;
	}
	data->out_used = 0;
	}

	eap_ikev2_state(data, PROC_MSG);
	return eap_ikev2_build_msg(data, ret, id);
	}


	static Boolean eap_ikev2_isKeyAvailable(struct eap_sm sm, void priv)
	{
	struct eap_ikev2_data *data = priv;
	return data->state == DONE && data->keymat_ok;
	}


	static u8 * eap_ikev2_getKey(struct eap_sm sm, void priv, size_t *len)
	{
	struct eap_ikev2_data *data = priv;
	u8 *key;

	if (data->state != DONE \|\| !data->keymat_ok)
	return NULL;

	key = os_malloc(EAP_MSK_LEN);
	if (key) {
	os_memcpy(key, data->keymat, EAP_MSK_LEN);
	*len = EAP_MSK_LEN;
	}

	return key;
	}


	static u8 * eap_ikev2_get_emsk(struct eap_sm sm, void priv, size_t *len)
	{
	struct eap_ikev2_data *data = priv;
	u8 *key;

	if (data->state != DONE \|\| !data->keymat_ok)
	return NULL;

	key = os_malloc(EAP_EMSK_LEN);
	if (key) {
	os_memcpy(key, data->keymat + EAP_MSK_LEN, EAP_EMSK_LEN);
	*len = EAP_EMSK_LEN;
	}

	return key;
	}


	static u8 * eap_ikev2_get_session_id(struct eap_sm sm, void priv, size_t *len)
	{
	struct eap_ikev2_data *data = priv;
	u8 *sid;
	size_t sid_len;
	size_t offset;

	if (data->state != DONE \|\| !data->keymat_ok)
	return NULL;

	sid_len = 1 + data->ikev2.i_nonce_len + data->ikev2.r_nonce_len;
	sid = os_malloc(sid_len);
	if (sid) {
	offset = 0;
	sid[offset] = EAP_TYPE_IKEV2;
	offset++;
	os_memcpy(sid + offset, data->ikev2.i_nonce,
	data->ikev2.i_nonce_len);
	offset += data->ikev2.i_nonce_len;
	os_memcpy(sid + offset, data->ikev2.r_nonce,
	data->ikev2.r_nonce_len);
	*len = sid_len;
	wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Derived Session-Id",
	sid, sid_len);
	}

	return sid;
	}


	int eap_peer_ikev2_register(void)
	{
	struct eap_method *eap;
	int ret;

	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
	EAP_VENDOR_IETF, EAP_TYPE_IKEV2,
	"IKEV2");
	if (eap == NULL)
	return -1;

	eap->init = eap_ikev2_init;
	eap->deinit = eap_ikev2_deinit;
	eap->process = eap_ikev2_process;
	eap->isKeyAvailable = eap_ikev2_isKeyAvailable;
	eap->getKey = eap_ikev2_getKey;
	eap->get_emsk = eap_ikev2_get_emsk;
	eap->getSessionId = eap_ikev2_get_session_id;

	ret = eap_peer_method_register(eap);
	if (ret)
	eap_peer_method_free(eap);
	return ret;
	}