wpa_ft.c

最新的Host AP 新添加了许多pcmcia 的驱动

/*
 * hostapd - IEEE 802.11r - Fast BSS Transition
 * Copyright (c) 2004-2007, Jouni Malinen <[e-mail]>
 *
 * 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 "config.h"
#include "wpa.h"
#include "aes_wrap.h"
#include "ieee802_11.h"
#include "defs.h"
#include "wpa_auth_i.h"
#include "wpa_auth_ie.h"


#ifdef CONFIG_IEEE80211R

static int wpa_ft_rrb_send(struct wpa_authenticator *wpa_auth, const u8 *dst,
			   const u8 *data, size_t data_len)
{
	if (wpa_auth->cb.send_ether == NULL)
		return -1;
	return wpa_auth->cb.send_ether(wpa_auth->cb.ctx, dst, ETH_P_RRB,
				       data, data_len);
}


static int wpa_ft_action_send(struct wpa_authenticator *wpa_auth,
			      const u8 *dst, const u8 *data, size_t data_len)
{
	if (wpa_auth->cb.send_ft_action == NULL)
		return -1;
	return wpa_auth->cb.send_ft_action(wpa_auth->cb.ctx, dst,
					   data, data_len);
}


static struct wpa_state_machine *
wpa_ft_add_sta(struct wpa_authenticator *wpa_auth, const u8 *sta_addr)
{
	if (wpa_auth->cb.add_sta == NULL)
		return NULL;
	return wpa_auth->cb.add_sta(wpa_auth->cb.ctx, sta_addr);
}


int wpa_write_mdie(struct wpa_auth_config *conf, u8 *buf, size_t len)
{
	u8 *pos = buf;
	u8 capab;
	if (len < 2 + sizeof(struct rsn_mdie))
		return -1;

	*pos++ = WLAN_EID_MOBILITY_DOMAIN;
	*pos++ = MOBILITY_DOMAIN_ID_LEN + 1;
	os_memcpy(pos, conf->mobility_domain, MOBILITY_DOMAIN_ID_LEN);
	pos += MOBILITY_DOMAIN_ID_LEN;
	capab = RSN_FT_CAPAB_FT_OVER_DS;
	*pos++ = capab;

	return pos - buf;
}


static int wpa_write_ftie(struct wpa_auth_config *conf, const u8 *r0kh_id,
			  size_t r0kh_id_len,
			  const u8 *anonce, const u8 *snonce,
			  u8 *buf, size_t len, const u8 *subelem,
			  size_t subelem_len)
{
	u8 *pos = buf, *ielen;
	struct rsn_ftie *hdr;

	if (len < 2 + sizeof(*hdr) + 2 + FT_R1KH_ID_LEN + 2 + r0kh_id_len +
	    subelem_len)
		return -1;

	*pos++ = WLAN_EID_FAST_BSS_TRANSITION;
	ielen = pos++;

	hdr = (struct rsn_ftie *) pos;
	os_memset(hdr, 0, sizeof(*hdr));
	pos += sizeof(*hdr);
	WPA_PUT_LE16(hdr->mic_control, 0);
	if (anonce)
		os_memcpy(hdr->anonce, anonce, WPA_NONCE_LEN);
	if (snonce)
		os_memcpy(hdr->snonce, snonce, WPA_NONCE_LEN);

	/* Optional Parameters */
	*pos++ = FTIE_SUBELEM_R1KH_ID;
	*pos++ = FT_R1KH_ID_LEN;
	os_memcpy(pos, conf->r1_key_holder, FT_R1KH_ID_LEN);
	pos += FT_R1KH_ID_LEN;

	if (r0kh_id) {
		*pos++ = FTIE_SUBELEM_R0KH_ID;
		*pos++ = r0kh_id_len;
		os_memcpy(pos, r0kh_id, r0kh_id_len);
		pos += r0kh_id_len;
	}

	if (subelem) {
		os_memcpy(pos, subelem, subelem_len);
		pos += subelem_len;
	}

	*ielen = pos - buf - 2;

	return pos - buf;
}


struct wpa_ft_pmk_r0_sa {
	struct wpa_ft_pmk_r0_sa *next;
	u8 pmk_r0[PMK_LEN];
	u8 pmk_r0_name[WPA_PMK_NAME_LEN];
	u8 spa[ETH_ALEN];
	/* TODO: expiration, identity, radius_class, EAP type, VLAN ID */
	int pmk_r1_pushed;
};

struct wpa_ft_pmk_r1_sa {
	struct wpa_ft_pmk_r1_sa *next;
	u8 pmk_r1[PMK_LEN];
	u8 pmk_r1_name[WPA_PMK_NAME_LEN];
	u8 spa[ETH_ALEN];
	/* TODO: expiration, identity, radius_class, EAP type, VLAN ID */
};

struct wpa_ft_pmk_cache {
	struct wpa_ft_pmk_r0_sa *pmk_r0;
	struct wpa_ft_pmk_r1_sa *pmk_r1;
};

struct wpa_ft_pmk_cache * wpa_ft_pmk_cache_init(void)
{
	struct wpa_ft_pmk_cache *cache;

	cache = os_zalloc(sizeof(*cache));

	return cache;
}


void wpa_ft_pmk_cache_deinit(struct wpa_ft_pmk_cache *cache)
{
	struct wpa_ft_pmk_r0_sa *r0, *r0prev;
	struct wpa_ft_pmk_r1_sa *r1, *r1prev;

	r0 = cache->pmk_r0;
	while (r0) {
		r0prev = r0;
		r0 = r0->next;
		os_memset(r0prev->pmk_r0, 0, PMK_LEN);
		os_free(r0prev);
	}

	r1 = cache->pmk_r1;
	while (r1) {
		r1prev = r1;
		r1 = r1->next;
		os_memset(r1prev->pmk_r1, 0, PMK_LEN);
		os_free(r1prev);
	}

	os_free(cache);
}


static int wpa_ft_store_pmk_r0(struct wpa_authenticator *wpa_auth,
			       const u8 *spa, const u8 *pmk_r0,
			       const u8 *pmk_r0_name)
{
	struct wpa_ft_pmk_cache *cache = wpa_auth->ft_pmk_cache;
	struct wpa_ft_pmk_r0_sa *r0;

	/* TODO: add expiration and limit on number of entries in cache */

	r0 = os_zalloc(sizeof(*r0));
	if (r0 == NULL)
		return -1;

	os_memcpy(r0->pmk_r0, pmk_r0, PMK_LEN);
	os_memcpy(r0->pmk_r0_name, pmk_r0_name, WPA_PMK_NAME_LEN);
	os_memcpy(r0->spa, spa, ETH_ALEN);

	r0->next = cache->pmk_r0;
	cache->pmk_r0 = r0;

	return 0;
}


static int wpa_ft_fetch_pmk_r0(struct wpa_authenticator *wpa_auth,
			       const u8 *spa, const u8 *pmk_r0_name,
			       u8 *pmk_r0)
{
	struct wpa_ft_pmk_cache *cache = wpa_auth->ft_pmk_cache;
	struct wpa_ft_pmk_r0_sa *r0;

	r0 = cache->pmk_r0;
	while (r0) {
		if (os_memcmp(r0->spa, spa, ETH_ALEN) == 0 &&
		    os_memcmp(r0->pmk_r0_name, pmk_r0_name, WPA_PMK_NAME_LEN)
		    == 0) {
			os_memcpy(pmk_r0, r0->pmk_r0, PMK_LEN);
			return 0;
		}

		r0 = r0->next;
	}

	return -1;
}


static int wpa_ft_store_pmk_r1(struct wpa_authenticator *wpa_auth,
			       const u8 *spa, const u8 *pmk_r1,
			       const u8 *pmk_r1_name)
{
	struct wpa_ft_pmk_cache *cache = wpa_auth->ft_pmk_cache;
	struct wpa_ft_pmk_r1_sa *r1;

	/* TODO: add expiration and limit on number of entries in cache */

	r1 = os_zalloc(sizeof(*r1));
	if (r1 == NULL)
		return -1;

	os_memcpy(r1->pmk_r1, pmk_r1, PMK_LEN);
	os_memcpy(r1->pmk_r1_name, pmk_r1_name, WPA_PMK_NAME_LEN);
	os_memcpy(r1->spa, spa, ETH_ALEN);

	r1->next = cache->pmk_r1;
	cache->pmk_r1 = r1;

	return 0;
}


static int wpa_ft_fetch_pmk_r1(struct wpa_authenticator *wpa_auth,
			       const u8 *spa, const u8 *pmk_r1_name,
			       u8 *pmk_r1)
{
	struct wpa_ft_pmk_cache *cache = wpa_auth->ft_pmk_cache;
	struct wpa_ft_pmk_r1_sa *r1;

	r1 = cache->pmk_r1;
	while (r1) {
		if (os_memcmp(r1->spa, spa, ETH_ALEN) == 0 &&
		    os_memcmp(r1->pmk_r1_name, pmk_r1_name, WPA_PMK_NAME_LEN)
		    == 0) {
			os_memcpy(pmk_r1, r1->pmk_r1, PMK_LEN);
			return 0;
		}

		r1 = r1->next;
	}

	return -1;
}


static int wpa_ft_pull_pmk_r1(struct wpa_authenticator *wpa_auth,
			      const u8 *s1kh_id, const u8 *r0kh_id,
			      size_t r0kh_id_len, const u8 *pmk_r0_name)
{
	struct ft_remote_r0kh *r0kh;
	struct ft_r0kh_r1kh_pull_frame frame, f;

	r0kh = wpa_auth->conf.r0kh_list;
	while (r0kh) {
		if (r0kh->id_len == r0kh_id_len &&
		    os_memcmp(r0kh->id, r0kh_id, r0kh_id_len) == 0)
			break;
		r0kh = r0kh->next;
	}
	if (r0kh == NULL)
		return -1;

	wpa_printf(MSG_DEBUG, "FT: Send PMK-R1 pull request to remote R0KH "
		   "address " MACSTR, MAC2STR(r0kh->addr));

	os_memset(&frame, 0, sizeof(frame));
	frame.frame_type = RSN_REMOTE_FRAME_TYPE_FT_RRB;
	frame.packet_type = FT_PACKET_R0KH_R1KH_PULL;
	frame.data_length = host_to_le16(FT_R0KH_R1KH_PULL_DATA_LEN);
	os_memcpy(frame.ap_address, wpa_auth->addr, ETH_ALEN);

	/* aes_wrap() does not support inplace encryption, so use a temporary
	 * buffer for the data. */
	if (os_get_random(f.nonce, sizeof(f.nonce))) {
		wpa_printf(MSG_DEBUG, "FT: Failed to get random data for "
			   "nonce");
		return -1;
	}
	os_memcpy(f.pmk_r0_name, pmk_r0_name, WPA_PMK_NAME_LEN);
	os_memcpy(f.r1kh_id, wpa_auth->conf.r1_key_holder, FT_R1KH_ID_LEN);
	os_memcpy(f.s1kh_id, s1kh_id, ETH_ALEN);

	if (aes_wrap(r0kh->key, (FT_R0KH_R1KH_PULL_DATA_LEN + 7) / 8,
		     f.nonce, frame.nonce) < 0)
		return -1;

	wpa_ft_rrb_send(wpa_auth, r0kh->addr, (u8 *) &frame, sizeof(frame));

	return 0;
}


int wpa_auth_derive_ptk_ft(struct wpa_state_machine *sm, const u8 *pmk,
			   struct wpa_ptk *ptk)
{
	u8 pmk_r0[PMK_LEN], pmk_r0_name[WPA_PMK_NAME_LEN];
	u8 pmk_r1[PMK_LEN], pmk_r1_name[WPA_PMK_NAME_LEN];
	u8 ptk_name[WPA_PMK_NAME_LEN];
	const u8 *mdid = sm->wpa_auth->conf.mobility_domain;
	const u8 *r0kh = sm->wpa_auth->conf.r0_key_holder;
	size_t r0kh_len = sm->wpa_auth->conf.r0_key_holder_len;
	const u8 *r1kh = sm->wpa_auth->conf.r1_key_holder;
	const u8 *ssid = sm->wpa_auth->conf.ssid;
	size_t ssid_len = sm->wpa_auth->conf.ssid_len;


	if (sm->xxkey_len == 0) {
		wpa_printf(MSG_DEBUG, "FT: XXKey not available for key "
			   "derivation");
		return -1;
	}

	wpa_derive_pmk_r0(sm->xxkey, sm->xxkey_len, ssid, ssid_len, mdid,
			  r0kh, r0kh_len, sm->addr, pmk_r0, pmk_r0_name);
	wpa_hexdump_key(MSG_DEBUG, "FT: PMK-R0", pmk_r0, PMK_LEN);
	wpa_hexdump(MSG_DEBUG, "FT: PMKR0Name", pmk_r0_name, WPA_PMK_NAME_LEN);
	wpa_ft_store_pmk_r0(sm->wpa_auth, sm->addr, pmk_r0, pmk_r0_name);

	wpa_derive_pmk_r1(pmk_r0, pmk_r0_name, r1kh, sm->addr,
			  pmk_r1, pmk_r1_name);
	wpa_hexdump_key(MSG_DEBUG, "FT: PMK-R1", pmk_r1, PMK_LEN);
	wpa_hexdump(MSG_DEBUG, "FT: PMKR1Name", pmk_r1_name, WPA_PMK_NAME_LEN);
	wpa_ft_store_pmk_r1(sm->wpa_auth, sm->addr, pmk_r1, pmk_r1_name);

	wpa_pmk_r1_to_ptk(pmk_r1, sm->SNonce, sm->ANonce, sm->addr,
			  sm->wpa_auth->addr, pmk_r1_name,
			  (u8 *) ptk, sizeof(*ptk), ptk_name);
	wpa_hexdump_key(MSG_DEBUG, "FT: PTK", (u8 *) ptk, sizeof(*ptk));
	wpa_hexdump(MSG_DEBUG, "FT: PTKName", ptk_name, WPA_PMK_NAME_LEN);

	return 0;
}


static inline int wpa_auth_get_seqnum(struct wpa_authenticator *wpa_auth,
				      const u8 *addr, int idx, u8 *seq)
{
	if (wpa_auth->cb.get_seqnum == NULL)
		return -1;
	return wpa_auth->cb.get_seqnum(wpa_auth->cb.ctx, addr, idx, seq);
}


#ifdef CONFIG_IEEE80211W
static inline int wpa_auth_get_seqnum_igtk(struct wpa_authenticator *wpa_auth,
					   const u8 *addr, int idx, u8 *seq)
{
	if (wpa_auth->cb.get_seqnum_igtk == NULL)
		return -1;
	return wpa_auth->cb.get_seqnum_igtk(wpa_auth->cb.ctx, addr, idx, seq);
}
#endif /* CONFIG_IEEE80211W */


static u8 * wpa_ft_gtk_subelem(struct wpa_state_machine *sm, size_t *len)
{
	u8 *subelem;
	struct wpa_group *gsm = sm->group;
	size_t subelem_len, pad_len;
	const u8 *key;
	size_t key_len;
	u8 keybuf[32];

	key_len = gsm->GTK_len;
	if (key_len > sizeof(keybuf))
		return NULL;

	/*
	 * Pad key for AES Key Wrap if it is not multiple of 8 bytes or is less
	 * than 16 bytes.
	 */
	pad_len = key_len % 8;
	if (pad_len)
		pad_len = 8 - pad_len;
	if (key_len + pad_len < 16)
		pad_len += 8;
	if (pad_len) {
		os_memcpy(keybuf, gsm->GTK[gsm->GN - 1], key_len);
		os_memset(keybuf + key_len, 0, pad_len);
		keybuf[key_len] = 0xdd;
		key_len += pad_len;
		key = keybuf;
	} else
		key = gsm->GTK[gsm->GN - 1];

	/*
	 * Sub-elem ID[1] | Length[1] | Key Info[1] | Key Length[1] | RSC[8] |
	 * Key[5..32].
	 */
	subelem_len = 12 + key_len + 8;
	subelem = os_zalloc(subelem_len);
	if (subelem == NULL)
		return NULL;

	subelem[0] = FTIE_SUBELEM_GTK;
	subelem[1] = 10 + key_len + 8;
	subelem[2] = gsm->GN & 0x03; /* Key ID in B0-B1 of Key Info */
	subelem[3] = gsm->GTK_len;
	wpa_auth_get_seqnum(sm->wpa_auth, NULL, gsm->GN, subelem + 4);
	if (aes_wrap(sm->PTK.kek, key_len / 8, key, subelem + 12)) {
		os_free(subelem);
		return NULL;
	}

	*len = subelem_len;
	return subelem;
}


#ifdef CONFIG_IEEE80211W
static u8 * wpa_ft_igtk_subelem(struct wpa_state_machine *sm, size_t *len)
{
	u8 *subelem, *pos;
	struct wpa_group *gsm = sm->group;
	size_t subelem_len;

	/* Sub-elem ID[1] | Length[1] | KeyID[2] | IPN[6] | Key Length[1] |
	 * Key[16+8] */
	subelem_len = 1 + 1 + 2 + 6 + 1 + WPA_IGTK_LEN + 8;
	subelem = os_zalloc(subelem_len);
	if (subelem == NULL)
		return NULL;

	pos = subelem;
	*pos++ = FTIE_SUBELEM_IGTK;
	*pos++ = subelem_len - 2;
	WPA_PUT_LE16(pos, gsm->GN_igtk);
	pos += 2;
	wpa_auth_get_seqnum_igtk(sm->wpa_auth, NULL, gsm->GN_igtk, pos);
	pos += 6;
	*pos++ = WPA_IGTK_LEN;
	if (aes_wrap(sm->PTK.kek, WPA_IGTK_LEN / 8,
		     gsm->IGTK[gsm->GN_igtk - 4], pos)) {
		os_free(subelem);
		return NULL;
	}

	*len = subelem_len;
	return subelem;
}
#endif /* CONFIG_IEEE80211W */


u8 * wpa_sm_write_assoc_resp_ies(struct wpa_state_machine *sm, u8 *pos,
				 size_t max_len, int auth_alg)
{
	u8 *end, *mdie, *ftie, *rsnie, *r0kh_id, *subelem = NULL;
	size_t mdie_len, ftie_len, rsnie_len, r0kh_id_len, subelem_len = 0;
	int res;
	struct wpa_auth_config *conf;
	struct rsn_ftie *_ftie;

	if (sm == NULL)
		return pos;

	conf = &sm->wpa_auth->conf;

	if (sm->wpa_key_mgmt != WPA_KEY_MGMT_FT_IEEE8021X &&
	    sm->wpa_key_mgmt != WPA_KEY_MGMT_FT_PSK)
		return pos;

	end = pos + max_len;

	/* RSN */
	res = wpa_write_rsn_ie(conf, pos, end - pos, sm->pmk_r1_name);
	if (res < 0)
		return pos;
	rsnie = pos;
	rsnie_len = res;
	pos += res;