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

/*
 * EAP-IKEv2 server (RFC 5106)
 * Copyright (c) 2007, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING 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 = 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	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*
	9	* Alternatively, this software may be distributed under the terms of BSD
	10	* license.
	11	*
	12	* See README and COPYING for more details.
	13	*/
	14
	15	#include "includes.h"
	16
	17	#include "common.h"
	18	#include "eap_i.h"
	19	#include "eap_common/eap_ikev2_common.h"
	20	#include "ikev2.h"
	21
	22
	23	struct eap_ikev2_data {
	24	struct ikev2_initiator_data ikev2;
	25	enum { MSG, FRAG_ACK, WAIT_FRAG_ACK, DONE, FAIL } state;
	26	struct wpabuf *in_buf;
	27	struct wpabuf *out_buf;
	28	size_t out_used;
	29	size_t fragment_size;
	30	int keys_ready;
	31	u8 keymat[EAP_MSK_LEN + EAP_EMSK_LEN];
	32	int keymat_ok;
	33	};
	34
	35
	36	static const u8 * eap_ikev2_get_shared_secret(void ctx, const u8 IDr,
	37	size_t IDr_len,
	38	size_t *secret_len)
	39	{
	40	struct eap_sm *sm = ctx;
	41
	42	if (IDr == NULL) {
	43	wpa_printf(MSG_DEBUG, "EAP-IKEV2: No IDr received - default "
	44	"to user identity from EAP-Identity");
	45	IDr = sm->identity;
	46	IDr_len = sm->identity_len;
	47	}
	48
	49	if (eap_user_get(sm, IDr, IDr_len, 0) < 0 \|\| sm->user == NULL \|\|
	50	sm->user->password == NULL) {
	51	wpa_printf(MSG_DEBUG, "EAP-IKEV2: No user entry found");
	52	return NULL;
	53	}
	54
	55	*secret_len = sm->user->password_len;
	56	return sm->user->password;
	57	}
	58
	59
	60	static const char * eap_ikev2_state_txt(int state)
	61	{
	62	switch (state) {
	63	case MSG:
	64	return "MSG";
65	case FRAG_ACK:
66	return "FRAG_ACK";
67	case WAIT_FRAG_ACK:
68	return "WAIT_FRAG_ACK";
69	case DONE:
70	return "DONE";
71	case FAIL:
72	return "FAIL";
73	default:
74	return "?";
75	}
76	}
77
78
79	static void eap_ikev2_state(struct eap_ikev2_data *data, int state)
80	{
81	wpa_printf(MSG_DEBUG, "EAP-IKEV2: %s -> %s",
82	eap_ikev2_state_txt(data->state),
83	eap_ikev2_state_txt(state));
84	data->state = state;
85	}
86
87
88	static void * eap_ikev2_init(struct eap_sm *sm)
89	{
90	struct eap_ikev2_data *data;
91
92	data = os_zalloc(sizeof(*data));
93	if (data == NULL)
94	return NULL;
95	data->state = MSG;
96	data->fragment_size = IKEV2_FRAGMENT_SIZE;
97	data->ikev2.state = SA_INIT;
98	data->ikev2.peer_auth = PEER_AUTH_SECRET;
99	data->ikev2.key_pad = (u8 *) os_strdup("Key Pad for EAP-IKEv2");
100	if (data->ikev2.key_pad == NULL)
101	goto failed;
102	data->ikev2.key_pad_len = 21;
103
104	/* TODO: make proposals configurable */
105	data->ikev2.proposal.proposal_num = 1;
106	data->ikev2.proposal.integ = AUTH_HMAC_SHA1_96;
107	data->ikev2.proposal.prf = PRF_HMAC_SHA1;
108	data->ikev2.proposal.encr = ENCR_AES_CBC;
109	data->ikev2.proposal.dh = DH_GROUP2_1024BIT_MODP;
110
111	data->ikev2.IDi = (u8 *) os_strdup("hostapd");
112	data->ikev2.IDi_len = 7;
113
114	data->ikev2.get_shared_secret = eap_ikev2_get_shared_secret;
115	data->ikev2.cb_ctx = sm;
116
117	return data;
118
119	failed:
120	ikev2_initiator_deinit(&data->ikev2);
121	os_free(data);
122	return NULL;
123	}
124
125
126	static void eap_ikev2_reset(struct eap_sm sm, void priv)
127	{
128	struct eap_ikev2_data *data = priv;
129	wpabuf_free(data->in_buf);
130	wpabuf_free(data->out_buf);
131	ikev2_initiator_deinit(&data->ikev2);
132	os_free(data);
133	}
134
135
136	static struct wpabuf * eap_ikev2_build_msg(struct eap_ikev2_data *data, u8 id)
137	{
138	struct wpabuf *req;
139	u8 flags;
140	size_t send_len, plen, icv_len = 0;
141
142	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Generating Request");
143
144	flags = 0;
145	send_len = wpabuf_len(data->out_buf) - data->out_used;
146	if (1 + send_len > data->fragment_size) {
147	send_len = data->fragment_size - 1;
148	flags \|= IKEV2_FLAGS_MORE_FRAGMENTS;
149	if (data->out_used == 0) {
150	flags \|= IKEV2_FLAGS_LENGTH_INCLUDED;
151	send_len -= 4;
152	}
153	}
154
155	plen = 1 + send_len;
156	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
157	plen += 4;
158	if (data->keys_ready) {
159	const struct ikev2_integ_alg *integ;
160	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Add Integrity Checksum "
161	"Data");
162	flags \|= IKEV2_FLAGS_ICV_INCLUDED;
163	integ = ikev2_get_integ(data->ikev2.proposal.integ);
164	if (integ == NULL) {
165	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unknown INTEG "
166	"transform / cannot generate ICV");
167	return NULL;
168	}
169	icv_len = integ->hash_len;
170
171	plen += icv_len;
172	}
173	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, plen,
174	EAP_CODE_REQUEST, id);
175	if (req == NULL)
176	return NULL;
177
178	wpabuf_put_u8(req, flags); /* Flags */
179	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
180	wpabuf_put_be32(req, wpabuf_len(data->out_buf));
181
182	wpabuf_put_data(req, wpabuf_head_u8(data->out_buf) + data->out_used,
183	send_len);
184	data->out_used += send_len;
185
186	if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
187	const u8 *msg = wpabuf_head(req);
188	size_t len = wpabuf_len(req);
189	ikev2_integ_hash(data->ikev2.proposal.integ,
190	data->ikev2.keys.SK_ai,
191	data->ikev2.keys.SK_integ_len,
192	msg, len, wpabuf_put(req, icv_len));
193	}
194
195	if (data->out_used == wpabuf_len(data->out_buf)) {
196	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
197	"(message sent completely)",
198	(unsigned long) send_len);
199	wpabuf_free(data->out_buf);
200	data->out_buf = NULL;
201	data->out_used = 0;
202	} else {
203	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
204	"(%lu more to send)", (unsigned long) send_len,
205	(unsigned long) wpabuf_len(data->out_buf) -
206	data->out_used);
207	eap_ikev2_state(data, WAIT_FRAG_ACK);
208	}
209
210	return req;
211	}
212
213
214	static struct wpabuf * eap_ikev2_buildReq(struct eap_sm sm, void priv, u8 id)
215	{
216	struct eap_ikev2_data *data = priv;
217
218	switch (data->state) {
219	case MSG:
220	if (data->out_buf == NULL) {
221	data->out_buf = ikev2_initiator_build(&data->ikev2);
222	if (data->out_buf == NULL) {
223	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to "
224	"generate IKEv2 message");
225	return NULL;
226	}
227	data->out_used = 0;
228	}
229	/* pass through */
230	case WAIT_FRAG_ACK:
231	return eap_ikev2_build_msg(data, id);
232	case FRAG_ACK:
233	return eap_ikev2_build_frag_ack(id, EAP_CODE_REQUEST);
234	default:
235	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unexpected state %d in "
236	"buildReq", data->state);
237	return NULL;
238	}
239	}
240
241
242	static Boolean eap_ikev2_check(struct eap_sm sm, void priv,
243	struct wpabuf *respData)
244	{
245	const u8 *pos;
246	size_t len;
247
248	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, respData,
249	&len);
250	if (pos == NULL) {
251	wpa_printf(MSG_INFO, "EAP-IKEV2: Invalid frame");
252	return TRUE;
253	}
254
255	return FALSE;
256	}
257
258
259	static int eap_ikev2_process_icv(struct eap_ikev2_data *data,
260	const struct wpabuf *respData,
261	u8 flags, const u8 pos, const u8 *end)
262	{
263	if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
264	int icv_len = eap_ikev2_validate_icv(
265	data->ikev2.proposal.integ, &data->ikev2.keys, 0,
266	respData, pos, *end);
267	if (icv_len < 0)
268	return -1;
269	/* Hide Integrity Checksum Data from further processing */
270	*end -= icv_len;
271	} else if (data->keys_ready) {
272	wpa_printf(MSG_INFO, "EAP-IKEV2: The message should have "
273	"included integrity checksum");
274	return -1;
275	}
276
277	return 0;
278	}
279
280
281	static int eap_ikev2_process_cont(struct eap_ikev2_data *data,
282	const u8 *buf, size_t len)
283	{
284	/* Process continuation of a pending message */
285	if (len > wpabuf_tailroom(data->in_buf)) {
286	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment overflow");
287	eap_ikev2_state(data, FAIL);
288	return -1;
289	}
290
291	wpabuf_put_data(data->in_buf, buf, len);
292	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes, waiting for %lu "
293	"bytes more", (unsigned long) len,
294	(unsigned long) wpabuf_tailroom(data->in_buf));
295
296	return 0;
297	}
298
299
300	static int eap_ikev2_process_fragment(struct eap_ikev2_data *data,
301	u8 flags, u32 message_length,
302	const u8 *buf, size_t len)
303	{
304	/* Process a fragment that is not the last one of the message */
305	if (data->in_buf == NULL && !(flags & IKEV2_FLAGS_LENGTH_INCLUDED)) {
306	wpa_printf(MSG_DEBUG, "EAP-IKEV2: No Message Length field in "
307	"a fragmented packet");
308	return -1;
309	}
310
311	if (data->in_buf == NULL) {
312	/* First fragment of the message */
313	data->in_buf = wpabuf_alloc(message_length);
314	if (data->in_buf == NULL) {
315	wpa_printf(MSG_DEBUG, "EAP-IKEV2: No memory for "
316	"message");
317	return -1;
318	}
319	wpabuf_put_data(data->in_buf, buf, len);
320	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes in first "
321	"fragment, waiting for %lu bytes more",
322	(unsigned long) len,
323	(unsigned long) wpabuf_tailroom(data->in_buf));
324	}
325
326	return 0;
327	}
328
329
330	static int eap_ikev2_server_keymat(struct eap_ikev2_data *data)
331	{
332	if (eap_ikev2_derive_keymat(
333	data->ikev2.proposal.prf, &data->ikev2.keys,
334	data->ikev2.i_nonce, data->ikev2.i_nonce_len,
335	data->ikev2.r_nonce, data->ikev2.r_nonce_len,
336	data->keymat) < 0) {
337	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to derive "
338	"key material");
339	return -1;
340	}
341	data->keymat_ok = 1;
342	return 0;
343	}
344
345
346	static void eap_ikev2_process(struct eap_sm sm, void priv,
347	struct wpabuf *respData)
348	{
349	struct eap_ikev2_data *data = priv;
350	const u8 start, pos, *end;
351	size_t len;
352	u8 flags;
353	u32 message_length = 0;
354	struct wpabuf tmpbuf;
355
356	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, respData,
357	&len);
358	if (pos == NULL)
359	return; /* Should not happen; message already verified */
360
361	start = pos;
362	end = start + len;
363
364	if (len == 0) {
365	/* fragment ack */
366	flags = 0;
367	} else
368	flags = *pos++;
369
370	if (eap_ikev2_process_icv(data, respData, flags, pos, &end) < 0) {
371	eap_ikev2_state(data, FAIL);
372	return;
373	}
374
375	if (flags & IKEV2_FLAGS_LENGTH_INCLUDED) {
376	if (end - pos < 4) {
377	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Message underflow");
378	eap_ikev2_state(data, FAIL);
379	return;
380	}
381	message_length = WPA_GET_BE32(pos);
382	pos += 4;
383
384	if (message_length < (u32) (end - pos)) {
385	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Invalid Message "
386	"Length (%d; %ld remaining in this msg)",
387	message_length, (long) (end - pos));
388	eap_ikev2_state(data, FAIL);
389	return;
390	}
391	}
392	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received packet: Flags 0x%x "
393	"Message Length %u", flags, message_length);
394
395	if (data->state == WAIT_FRAG_ACK) {
396	if (len != 0) {
397	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unexpected payload "
398	"in WAIT_FRAG_ACK state");
399	eap_ikev2_state(data, FAIL);
400	return;
401	}
402	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment acknowledged");
403	eap_ikev2_state(data, MSG);
404	return;
405	}
406
407	if (data->in_buf && eap_ikev2_process_cont(data, pos, end - pos) < 0) {
408	eap_ikev2_state(data, FAIL);
409	return;
410	}
411
412	if (flags & IKEV2_FLAGS_MORE_FRAGMENTS) {
413	if (eap_ikev2_process_fragment(data, flags, message_length,
414	pos, end - pos) < 0)
415	eap_ikev2_state(data, FAIL);
416	else
417	eap_ikev2_state(data, FRAG_ACK);
418	return;
ab17e3f2 JM	419	} else if (data->state == FRAG_ACK) {
	420	wpa_printf(MSG_DEBUG, "EAP-TNC: All fragments received");
	421	data->state = MSG;
6fc6879b JM	422	}
	423
	424	if (data->in_buf == NULL) {
	425	/* Wrap unfragmented messages as wpabuf without extra copy */
	426	wpabuf_set(&tmpbuf, pos, end - pos);
	427	data->in_buf = &tmpbuf;
	428	}
	429
	430	if (ikev2_initiator_process(&data->ikev2, data->in_buf) < 0) {
	431	if (data->in_buf == &tmpbuf)
	432	data->in_buf = NULL;
	433	eap_ikev2_state(data, FAIL);
	434	return;
	435	}
	436
	437	switch (data->ikev2.state) {
	438	case SA_AUTH:
	439	/* SA_INIT was sent out, so message have to be
	440	* integrity protected from now on. */
	441	data->keys_ready = 1;
	442	break;
	443	case IKEV2_DONE:
	444	if (data->state == FAIL)
	445	break;
	446	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication completed "
	447	"successfully");
	448	if (eap_ikev2_server_keymat(data))
	449	break;
	450	eap_ikev2_state(data, DONE);
	451	break;
	452	default:
	453	break;
	454	}
	455
	456	if (data->in_buf != &tmpbuf)
	457	wpabuf_free(data->in_buf);
	458	data->in_buf = NULL;
	459	}
	460
	461
	462	static Boolean eap_ikev2_isDone(struct eap_sm sm, void priv)
	463	{
	464	struct eap_ikev2_data *data = priv;
	465	return data->state == DONE \|\| data->state == FAIL;
	466	}
	467
	468
	469	static Boolean eap_ikev2_isSuccess(struct eap_sm sm, void priv)
	470	{
	471	struct eap_ikev2_data *data = priv;
	472	return data->state == DONE && data->ikev2.state == IKEV2_DONE &&
	473	data->keymat_ok;
	474	}
	475
	476
	477	static u8 * eap_ikev2_getKey(struct eap_sm sm, void priv, size_t *len)
	478	{
	479	struct eap_ikev2_data *data = priv;
	480	u8 *key;
	481
	482	if (data->state != DONE \|\| !data->keymat_ok)
	483	return NULL;
	484
	485	key = os_malloc(EAP_MSK_LEN);
486	if (key) {
487	os_memcpy(key, data->keymat, EAP_MSK_LEN);
488	*len = EAP_MSK_LEN;
489	}
490
491	return key;
492	}
493
494
495	static u8 * eap_ikev2_get_emsk(struct eap_sm sm, void priv, size_t *len)
496	{
497	struct eap_ikev2_data *data = priv;
498	u8 *key;
499
500	if (data->state != DONE \|\| !data->keymat_ok)
501	return NULL;
502
503	key = os_malloc(EAP_EMSK_LEN);
504	if (key) {
505	os_memcpy(key, data->keymat + EAP_MSK_LEN, EAP_EMSK_LEN);
506	*len = EAP_EMSK_LEN;
507	}
508
509	return key;
510	}
511
512
513	int eap_server_ikev2_register(void)
514	{
515	struct eap_method *eap;
516	int ret;
517
518	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
519	EAP_VENDOR_IETF, EAP_TYPE_IKEV2,
520	"IKEV2");
521	if (eap == NULL)
522	return -1;
523
524	eap->init = eap_ikev2_init;
525	eap->reset = eap_ikev2_reset;
526	eap->buildReq = eap_ikev2_buildReq;
527	eap->check = eap_ikev2_check;
528	eap->process = eap_ikev2_process;
529	eap->isDone = eap_ikev2_isDone;
530	eap->getKey = eap_ikev2_getKey;
531	eap->isSuccess = eap_ikev2_isSuccess;
532	eap->get_emsk = eap_ikev2_get_emsk;
533
534	ret = eap_server_method_register(eap);
535	if (ret)
536	eap_server_method_free(eap);
537	return ret;
538	}