[thirdparty/hostap.git] / src / eap_server / eap_server_ikev2.c

/*
 * EAP-IKEv2 server (RFC 5106)
 * Copyright (c) 2007, 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_initiator_data ikev2;
	enum { MSG, FRAG_ACK, 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 u8 * eap_ikev2_get_shared_secret(void *ctx, const u8 *IDr,
					      size_t IDr_len,
					      size_t *secret_len)
{
	struct eap_sm *sm = ctx;

	if (IDr == NULL) {
		wpa_printf(MSG_DEBUG, "EAP-IKEV2: No IDr received - default "
			   "to user identity from EAP-Identity");
		IDr = sm->identity;
		IDr_len = sm->identity_len;
	}

	if (eap_user_get(sm, IDr, IDr_len, 0) < 0 || sm->user == NULL ||
	    sm->user->password == NULL) {
		wpa_printf(MSG_DEBUG, "EAP-IKEV2: No user entry found");
		return NULL;
	}

	*secret_len = sm->user->password_len;
	return sm->user->password;
}


static const char * eap_ikev2_state_txt(int state)
{
	switch (state) {
	case MSG:
		return "MSG";
	case FRAG_ACK:
		return "FRAG_ACK";
	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;

	data = os_zalloc(sizeof(*data));
	if (data == NULL)
		return NULL;
	data->state = MSG;
	data->fragment_size = sm->fragment_size > 0 ? sm->fragment_size :
		IKEV2_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;

	/* TODO: make proposals configurable */
	data->ikev2.proposal.proposal_num = 1;
	data->ikev2.proposal.integ = AUTH_HMAC_SHA1_96;
	data->ikev2.proposal.prf = PRF_HMAC_SHA1;
	data->ikev2.proposal.encr = ENCR_AES_CBC;
	data->ikev2.proposal.dh = DH_GROUP2_1024BIT_MODP;

	data->ikev2.IDi = (u8 *) os_strdup("hostapd");
	data->ikev2.IDi_len = 7;

	data->ikev2.get_shared_secret = eap_ikev2_get_shared_secret;
	data->ikev2.cb_ctx = sm;

	return data;

failed:
	ikev2_initiator_deinit(&data->ikev2);
	os_free(data);
	return NULL;
}


static void eap_ikev2_reset(struct eap_sm *sm, void *priv)
{
	struct eap_ikev2_data *data = priv;
	wpabuf_free(data->in_buf);
	wpabuf_free(data->out_buf);
	ikev2_initiator_deinit(&data->ikev2);
	os_free(data);
}


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

	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Generating Request");

	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;
	}
	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, plen,
			    EAP_CODE_REQUEST, id);
	if (req == NULL)
		return NULL;

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

	wpabuf_put_data(req, 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(req);
		size_t len = wpabuf_len(req);
		ikev2_integ_hash(data->ikev2.proposal.integ,
				 data->ikev2.keys.SK_ai,
				 data->ikev2.keys.SK_integ_len,
				 msg, len, wpabuf_put(req, icv_len));
	}

	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;
	} 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 req;
}


static struct wpabuf * eap_ikev2_buildReq(struct eap_sm *sm, void *priv, u8 id)
{
	struct eap_ikev2_data *data = priv;

	switch (data->state) {
	case MSG:
		if (data->out_buf == NULL) {
			data->out_buf = ikev2_initiator_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;
		}
		/* pass through */
	case WAIT_FRAG_ACK:
		return eap_ikev2_build_msg(data, id);
	case FRAG_ACK:
		return eap_ikev2_build_frag_ack(id, EAP_CODE_REQUEST);
	default:
		wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unexpected state %d in "
			   "buildReq", data->state);
		return NULL;
	}
}


static Boolean eap_ikev2_check(struct eap_sm *sm, void *priv,
			       struct wpabuf *respData)
{
	const u8 *pos;
	size_t len;

	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, respData,
			       &len);
	if (pos == NULL) {
		wpa_printf(MSG_INFO, "EAP-IKEV2: Invalid frame");
		return TRUE;
	}

	return FALSE;
}


static int eap_ikev2_process_icv(struct eap_ikev2_data *data,
				 const struct wpabuf *respData,
				 u8 flags, const u8 *pos, const u8 **end)
{
	if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
		int icv_len = eap_ikev2_validate_icv(
			data->ikev2.proposal.integ, &data->ikev2.keys, 0,
			respData, pos, *end);
		if (icv_len < 0)
			return -1;
		/* Hide Integrity Checksum Data from further processing */
		*end -= icv_len;
	} else if (data->keys_ready) {
		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 int eap_ikev2_process_fragment(struct eap_ikev2_data *data,
				      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");
		return -1;
	}

	if (data->in_buf == NULL) {
		/* First fragment of the message */
		data->in_buf = wpabuf_alloc(message_length);
		if (data->in_buf == NULL) {
			wpa_printf(MSG_DEBUG, "EAP-IKEV2: No memory for "
				   "message");
			return -1;
		}
		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));
	}

	return 0;
}


static int eap_ikev2_server_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 void eap_ikev2_process(struct eap_sm *sm, void *priv,
			      struct wpabuf *respData)
{
	struct eap_ikev2_data *data = priv;
	const u8 *start, *pos, *end;
	size_t len;
	u8 flags;
	u32 message_length = 0;
	struct wpabuf tmpbuf;

	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, respData,
			       &len);
	if (pos == NULL)
		return; /* Should not happen; message already verified */

	start = pos;
	end = start + len;

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

	if (eap_ikev2_process_icv(data, respData, flags, pos, &end) < 0) {
		eap_ikev2_state(data, FAIL);
		return;
	}

	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED) {
		if (end - pos < 4) {
			wpa_printf(MSG_DEBUG, "EAP-IKEV2: Message underflow");
			eap_ikev2_state(data, FAIL);
			return;
		}
		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));
			eap_ikev2_state(data, FAIL);
			return;
		}
	}
	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");
			eap_ikev2_state(data, FAIL);
			return;
		}
		wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment acknowledged");
		eap_ikev2_state(data, MSG);
		return;
	}

	if (data->in_buf && eap_ikev2_process_cont(data, pos, end - pos) < 0) {
		eap_ikev2_state(data, FAIL);
		return;
	}
		
	if (flags & IKEV2_FLAGS_MORE_FRAGMENTS) {
		if (eap_ikev2_process_fragment(data, flags, message_length,
					       pos, end - pos) < 0)
			eap_ikev2_state(data, FAIL);
		else
			eap_ikev2_state(data, FRAG_ACK);
		return;
	} else if (data->state == FRAG_ACK) {
		wpa_printf(MSG_DEBUG, "EAP-TNC: All fragments received");
		data->state = MSG;
	}

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

	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:
		if (data->state == FAIL)
			break;
		wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication completed "
			   "successfully");
		if (eap_ikev2_server_keymat(data))
			break;
		eap_ikev2_state(data, DONE);
		break;
	default:
		break;
	}

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


static Boolean eap_ikev2_isDone(struct eap_sm *sm, void *priv)
{
	struct eap_ikev2_data *data = priv;
	return data->state == DONE || data->state == FAIL;
}


static Boolean eap_ikev2_isSuccess(struct eap_sm *sm, void *priv)
{
	struct eap_ikev2_data *data = priv;
	return data->state == DONE && data->ikev2.state == IKEV2_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;
}


int eap_server_ikev2_register(void)
{
	struct eap_method *eap;
	int ret;

	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
				      EAP_VENDOR_IETF, EAP_TYPE_IKEV2,
				      "IKEV2");
	if (eap == NULL)
		return -1;

	eap->init = eap_ikev2_init;
	eap->reset = eap_ikev2_reset;
	eap->buildReq = eap_ikev2_buildReq;
	eap->check = eap_ikev2_check;
	eap->process = eap_ikev2_process;
	eap->isDone = eap_ikev2_isDone;
	eap->getKey = eap_ikev2_getKey;
	eap->isSuccess = eap_ikev2_isSuccess;
	eap->get_emsk = eap_ikev2_get_emsk;

	ret = eap_server_method_register(eap);
	if (ret)
		eap_server_method_free(eap);
	return ret;
}
Commit	Line	Data
6fc6879b JM	1	/*
	2	* EAP-IKEv2 server (RFC 5106)
	3	* Copyright (c) 2007, Jouni Malinen <j@w1.fi>
	4	*
0f3d578e JM	5	* This software may be distributed under the terms of the BSD license.
0f3d578e JM	6	* See README for more details.
6fc6879b JM	7	*/
	8
	9	#include "includes.h"
	10
	11	#include "common.h"
	12	#include "eap_i.h"
	13	#include "eap_common/eap_ikev2_common.h"
	14	#include "ikev2.h"
	15
	16
	17	struct eap_ikev2_data {
	18	struct ikev2_initiator_data ikev2;
	19	enum { MSG, FRAG_ACK, WAIT_FRAG_ACK, DONE, FAIL } state;
	20	struct wpabuf *in_buf;
	21	struct wpabuf *out_buf;
	22	size_t out_used;
	23	size_t fragment_size;
	24	int keys_ready;
	25	u8 keymat[EAP_MSK_LEN + EAP_EMSK_LEN];
	26	int keymat_ok;
	27	};
	28
	29
	30	static const u8 * eap_ikev2_get_shared_secret(void ctx, const u8 IDr,
	31	size_t IDr_len,
	32	size_t *secret_len)
	33	{
	34	struct eap_sm *sm = ctx;
	35
	36	if (IDr == NULL) {
	37	wpa_printf(MSG_DEBUG, "EAP-IKEV2: No IDr received - default "
	38	"to user identity from EAP-Identity");
	39	IDr = sm->identity;
	40	IDr_len = sm->identity_len;
	41	}
	42
	43	if (eap_user_get(sm, IDr, IDr_len, 0) < 0 \|\| sm->user == NULL \|\|
	44	sm->user->password == NULL) {
	45	wpa_printf(MSG_DEBUG, "EAP-IKEV2: No user entry found");
	46	return NULL;
	47	}
	48
	49	*secret_len = sm->user->password_len;
	50	return sm->user->password;
	51	}
	52
	53
	54	static const char * eap_ikev2_state_txt(int state)
	55	{
	56	switch (state) {
	57	case MSG:
	58	return "MSG";
	59	case FRAG_ACK:
	60	return "FRAG_ACK";
	61	case WAIT_FRAG_ACK:
	62	return "WAIT_FRAG_ACK";
	63	case DONE:
	64	return "DONE";
	65	case FAIL:
	66	return "FAIL";
	67	default:
	68	return "?";
	69	}
	70	}
71
72
73	static void eap_ikev2_state(struct eap_ikev2_data *data, int state)
74	{
75	wpa_printf(MSG_DEBUG, "EAP-IKEV2: %s -> %s",
76	eap_ikev2_state_txt(data->state),
77	eap_ikev2_state_txt(state));
78	data->state = state;
79	}
80
81
82	static void * eap_ikev2_init(struct eap_sm *sm)
83	{
84	struct eap_ikev2_data *data;
85
86	data = os_zalloc(sizeof(*data));
87	if (data == NULL)
88	return NULL;
89	data->state = MSG;
7f6ec672 JM	90	data->fragment_size = sm->fragment_size > 0 ? sm->fragment_size :
7f6ec672 JM	91	IKEV2_FRAGMENT_SIZE;
6fc6879b JM	92	data->ikev2.state = SA_INIT;
	93	data->ikev2.peer_auth = PEER_AUTH_SECRET;
	94	data->ikev2.key_pad = (u8 *) os_strdup("Key Pad for EAP-IKEv2");
	95	if (data->ikev2.key_pad == NULL)
	96	goto failed;
	97	data->ikev2.key_pad_len = 21;
	98
	99	/* TODO: make proposals configurable */
	100	data->ikev2.proposal.proposal_num = 1;
	101	data->ikev2.proposal.integ = AUTH_HMAC_SHA1_96;
	102	data->ikev2.proposal.prf = PRF_HMAC_SHA1;
	103	data->ikev2.proposal.encr = ENCR_AES_CBC;
	104	data->ikev2.proposal.dh = DH_GROUP2_1024BIT_MODP;
	105
	106	data->ikev2.IDi = (u8 *) os_strdup("hostapd");
	107	data->ikev2.IDi_len = 7;
	108
	109	data->ikev2.get_shared_secret = eap_ikev2_get_shared_secret;
	110	data->ikev2.cb_ctx = sm;
	111
	112	return data;
	113
	114	failed:
	115	ikev2_initiator_deinit(&data->ikev2);
	116	os_free(data);
	117	return NULL;
	118	}
	119
	120
	121	static void eap_ikev2_reset(struct eap_sm sm, void priv)
	122	{
	123	struct eap_ikev2_data *data = priv;
	124	wpabuf_free(data->in_buf);
	125	wpabuf_free(data->out_buf);
	126	ikev2_initiator_deinit(&data->ikev2);
	127	os_free(data);
	128	}
	129
	130
	131	static struct wpabuf * eap_ikev2_build_msg(struct eap_ikev2_data *data, u8 id)
	132	{
	133	struct wpabuf *req;
	134	u8 flags;
	135	size_t send_len, plen, icv_len = 0;
	136
	137	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Generating Request");
	138
	139	flags = 0;
	140	send_len = wpabuf_len(data->out_buf) - data->out_used;
	141	if (1 + send_len > data->fragment_size) {
	142	send_len = data->fragment_size - 1;
	143	flags \|= IKEV2_FLAGS_MORE_FRAGMENTS;
	144	if (data->out_used == 0) {
	145	flags \|= IKEV2_FLAGS_LENGTH_INCLUDED;
	146	send_len -= 4;
	147	}
	148	}
	149
	150	plen = 1 + send_len;
	151	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
	152	plen += 4;
	153	if (data->keys_ready) {
	154	const struct ikev2_integ_alg *integ;
	155	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Add Integrity Checksum "
156	"Data");
157	flags \|= IKEV2_FLAGS_ICV_INCLUDED;
158	integ = ikev2_get_integ(data->ikev2.proposal.integ);
159	if (integ == NULL) {
160	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unknown INTEG "
161	"transform / cannot generate ICV");
162	return NULL;
163	}
164	icv_len = integ->hash_len;
165
166	plen += icv_len;
167	}
168	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, plen,
169	EAP_CODE_REQUEST, id);
170	if (req == NULL)
171	return NULL;
172
173	wpabuf_put_u8(req, flags); /* Flags */
174	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
175	wpabuf_put_be32(req, wpabuf_len(data->out_buf));
176
177	wpabuf_put_data(req, wpabuf_head_u8(data->out_buf) + data->out_used,
178	send_len);
179	data->out_used += send_len;
180
181	if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
182	const u8 *msg = wpabuf_head(req);
183	size_t len = wpabuf_len(req);
184	ikev2_integ_hash(data->ikev2.proposal.integ,
185	data->ikev2.keys.SK_ai,
186	data->ikev2.keys.SK_integ_len,
187	msg, len, wpabuf_put(req, icv_len));
188	}
189
190	if (data->out_used == wpabuf_len(data->out_buf)) {
191	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
192	"(message sent completely)",
193	(unsigned long) send_len);
194	wpabuf_free(data->out_buf);
195	data->out_buf = NULL;
196	data->out_used = 0;
197	} else {
198	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
199	"(%lu more to send)", (unsigned long) send_len,
200	(unsigned long) wpabuf_len(data->out_buf) -
201	data->out_used);
202	eap_ikev2_state(data, WAIT_FRAG_ACK);
203	}
204
205	return req;
206	}
207
208
209	static struct wpabuf * eap_ikev2_buildReq(struct eap_sm sm, void priv, u8 id)
210	{
211	struct eap_ikev2_data *data = priv;
212
213	switch (data->state) {
214	case MSG:
215	if (data->out_buf == NULL) {
216	data->out_buf = ikev2_initiator_build(&data->ikev2);
217	if (data->out_buf == NULL) {
218	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to "
219	"generate IKEv2 message");
220	return NULL;
221	}
222	data->out_used = 0;
223	}
224	/* pass through */
225	case WAIT_FRAG_ACK:
226	return eap_ikev2_build_msg(data, id);
227	case FRAG_ACK:
228	return eap_ikev2_build_frag_ack(id, EAP_CODE_REQUEST);
229	default:
230	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unexpected state %d in "
231	"buildReq", data->state);
232	return NULL;
233	}
234	}
235
236
237	static Boolean eap_ikev2_check(struct eap_sm sm, void priv,
238	struct wpabuf *respData)
239	{
240	const u8 *pos;
241	size_t len;
242
243	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, respData,
244	&len);
245	if (pos == NULL) {
246	wpa_printf(MSG_INFO, "EAP-IKEV2: Invalid frame");
247	return TRUE;
248	}
249
250	return FALSE;
251	}
252
253
254	static int eap_ikev2_process_icv(struct eap_ikev2_data *data,
255	const struct wpabuf *respData,
256	u8 flags, const u8 pos, const u8 *end)
257	{
258	if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
259	int icv_len = eap_ikev2_validate_icv(
260	data->ikev2.proposal.integ, &data->ikev2.keys, 0,
261	respData, pos, *end);
262	if (icv_len < 0)
263	return -1;
264	/* Hide Integrity Checksum Data from further processing */
265	*end -= icv_len;
266	} else if (data->keys_ready) {
267	wpa_printf(MSG_INFO, "EAP-IKEV2: The message should have "
268	"included integrity checksum");
269	return -1;
270	}
271
272	return 0;
273	}
274
275
276	static int eap_ikev2_process_cont(struct eap_ikev2_data *data,
277	const u8 *buf, size_t len)
278	{
279	/* Process continuation of a pending message */
280	if (len > wpabuf_tailroom(data->in_buf)) {
281	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment overflow");
282	eap_ikev2_state(data, FAIL);
283	return -1;
284	}
285
286	wpabuf_put_data(data->in_buf, buf, len);
287	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes, waiting for %lu "
288	"bytes more", (unsigned long) len,
289	(unsigned long) wpabuf_tailroom(data->in_buf));
290
291	return 0;
292	}
293
294
295	static int eap_ikev2_process_fragment(struct eap_ikev2_data *data,
296	u8 flags, u32 message_length,
297	const u8 *buf, size_t len)
298	{
299	/* Process a fragment that is not the last one of the message */
300	if (data->in_buf == NULL && !(flags & IKEV2_FLAGS_LENGTH_INCLUDED)) {
301	wpa_printf(MSG_DEBUG, "EAP-IKEV2: No Message Length field in "
302	"a fragmented packet");
303	return -1;
304	}
305
306	if (data->in_buf == NULL) {
307	/* First fragment of the message */
308	data->in_buf = wpabuf_alloc(message_length);
309	if (data->in_buf == NULL) {
310	wpa_printf(MSG_DEBUG, "EAP-IKEV2: No memory for "
311	"message");
312	return -1;
313	}
314	wpabuf_put_data(data->in_buf, buf, len);
315	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes in first "
316	"fragment, waiting for %lu bytes more",
317	(unsigned long) len,
318	(unsigned long) wpabuf_tailroom(data->in_buf));
319	}
320
321	return 0;
322	}
323
324
325	static int eap_ikev2_server_keymat(struct eap_ikev2_data *data)
326	{
327	if (eap_ikev2_derive_keymat(
328	data->ikev2.proposal.prf, &data->ikev2.keys,
329	data->ikev2.i_nonce, data->ikev2.i_nonce_len,
330	data->ikev2.r_nonce, data->ikev2.r_nonce_len,
331	data->keymat) < 0) {
332	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to derive "
333	"key material");
334	return -1;
335	}
336	data->keymat_ok = 1;
337	return 0;
338	}
339
340
341	static void eap_ikev2_process(struct eap_sm sm, void priv,
342	struct wpabuf *respData)
343	{
344	struct eap_ikev2_data *data = priv;
345	const u8 start, pos, *end;
346	size_t len;
347	u8 flags;
348	u32 message_length = 0;
349	struct wpabuf tmpbuf;
350
351	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, respData,
352	&len);
353	if (pos == NULL)
354	return; /* Should not happen; message already verified */
355
356	start = pos;
357	end = start + len;
358
359	if (len == 0) {
360	/* fragment ack */
361	flags = 0;
362	} else
363	flags = *pos++;
364
365	if (eap_ikev2_process_icv(data, respData, flags, pos, &end) < 0) {
366	eap_ikev2_state(data, FAIL);
367	return;
368	}
369
370	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED) {
371	if (end - pos < 4) {
372	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Message underflow");
373	eap_ikev2_state(data, FAIL);
374	return;
375	}
376	message_length = WPA_GET_BE32(pos);
377	pos += 4;
378
379	if (message_length < (u32) (end - pos)) {
380	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Invalid Message "
381	"Length (%d; %ld remaining in this msg)",
382	message_length, (long) (end - pos));
383	eap_ikev2_state(data, FAIL);
384	return;
385	}
386	}
387	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received packet: Flags 0x%x "
388	"Message Length %u", flags, message_length);
389
390	if (data->state == WAIT_FRAG_ACK) {
391	if (len != 0) {
392	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unexpected payload "
393	"in WAIT_FRAG_ACK state");
394	eap_ikev2_state(data, FAIL);
395	return;
396	}
397	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment acknowledged");
398	eap_ikev2_state(data, MSG);
399	return;
400	}
401
402	if (data->in_buf && eap_ikev2_process_cont(data, pos, end - pos) < 0) {
403	eap_ikev2_state(data, FAIL);
404	return;
405	}
406
407	if (flags & IKEV2_FLAGS_MORE_FRAGMENTS) {
408	if (eap_ikev2_process_fragment(data, flags, message_length,
409	pos, end - pos) < 0)
410	eap_ikev2_state(data, FAIL);
411	else
412	eap_ikev2_state(data, FRAG_ACK);
413	return;
ab17e3f2 JM	414	} else if (data->state == FRAG_ACK) {
	415	wpa_printf(MSG_DEBUG, "EAP-TNC: All fragments received");
	416	data->state = MSG;
6fc6879b JM	417	}
	418
	419	if (data->in_buf == NULL) {
	420	/* Wrap unfragmented messages as wpabuf without extra copy */
	421	wpabuf_set(&tmpbuf, pos, end - pos);
	422	data->in_buf = &tmpbuf;
	423	}
	424
	425	if (ikev2_initiator_process(&data->ikev2, data->in_buf) < 0) {
	426	if (data->in_buf == &tmpbuf)
	427	data->in_buf = NULL;
	428	eap_ikev2_state(data, FAIL);
	429	return;
	430	}
	431
	432	switch (data->ikev2.state) {
	433	case SA_AUTH:
	434	/* SA_INIT was sent out, so message have to be
	435	* integrity protected from now on. */
	436	data->keys_ready = 1;
	437	break;
	438	case IKEV2_DONE:
	439	if (data->state == FAIL)
	440	break;
	441	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication completed "
	442	"successfully");
	443	if (eap_ikev2_server_keymat(data))
	444	break;
	445	eap_ikev2_state(data, DONE);
	446	break;
	447	default:
	448	break;
	449	}
	450
	451	if (data->in_buf != &tmpbuf)
	452	wpabuf_free(data->in_buf);
	453	data->in_buf = NULL;
	454	}
	455
	456
	457	static Boolean eap_ikev2_isDone(struct eap_sm sm, void priv)
	458	{
	459	struct eap_ikev2_data *data = priv;
	460	return data->state == DONE \|\| data->state == FAIL;
	461	}
	462
	463
	464	static Boolean eap_ikev2_isSuccess(struct eap_sm sm, void priv)
	465	{
	466	struct eap_ikev2_data *data = priv;
	467	return data->state == DONE && data->ikev2.state == IKEV2_DONE &&
	468	data->keymat_ok;
	469	}
	470
	471
	472	static u8 * eap_ikev2_getKey(struct eap_sm sm, void priv, size_t *len)
	473	{
	474	struct eap_ikev2_data *data = priv;
	475	u8 *key;
	476
	477	if (data->state != DONE \|\| !data->keymat_ok)
	478	return NULL;
	479
	480	key = os_malloc(EAP_MSK_LEN);
481	if (key) {
482	os_memcpy(key, data->keymat, EAP_MSK_LEN);
483	*len = EAP_MSK_LEN;
484	}
485
486	return key;
487	}
488
489
490	static u8 * eap_ikev2_get_emsk(struct eap_sm sm, void priv, size_t *len)
491	{
492	struct eap_ikev2_data *data = priv;
493	u8 *key;
494
495	if (data->state != DONE \|\| !data->keymat_ok)
496	return NULL;
497
498	key = os_malloc(EAP_EMSK_LEN);
499	if (key) {
500	os_memcpy(key, data->keymat + EAP_MSK_LEN, EAP_EMSK_LEN);
501	*len = EAP_EMSK_LEN;
502	}
503
504	return key;
505	}
506
507
508	int eap_server_ikev2_register(void)
509	{
510	struct eap_method *eap;
511	int ret;
512
513	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
514	EAP_VENDOR_IETF, EAP_TYPE_IKEV2,
515	"IKEV2");
516	if (eap == NULL)
517	return -1;
518
519	eap->init = eap_ikev2_init;
520	eap->reset = eap_ikev2_reset;
521	eap->buildReq = eap_ikev2_buildReq;
522	eap->check = eap_ikev2_check;
523	eap->process = eap_ikev2_process;
524	eap->isDone = eap_ikev2_isDone;
525	eap->getKey = eap_ikev2_getKey;
526	eap->isSuccess = eap_ikev2_isSuccess;
527	eap->get_emsk = eap_ikev2_get_emsk;
528
529	ret = eap_server_method_register(eap);
530	if (ret)
531	eap_server_method_free(eap);
532	return ret;
533	}