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ieee80211_crypto.h revision 1.3
      1 /*	$NetBSD: ieee80211_crypto.h,v 1.3 2005/06/22 06:16:02 dyoung Exp $	*/
      2 /*-
      3  * Copyright (c) 2001 Atsushi Onoe
      4  * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. The name of the author may not be used to endorse or promote products
     16  *    derived from this software without specific prior written permission.
     17  *
     18  * Alternatively, this software may be distributed under the terms of the
     19  * GNU General Public License ("GPL") version 2 as published by the Free
     20  * Software Foundation.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     32  *
     33  * $FreeBSD: src/sys/net80211/ieee80211_crypto.h,v 1.5 2004/12/31 22:44:26 sam Exp $
     34  */
     35 #ifndef _NET80211_IEEE80211_CRYPTO_H_
     36 #define _NET80211_IEEE80211_CRYPTO_H_
     37 
     38 /*
     39  * 802.11 protocol crypto-related definitions.
     40  */
     41 #define	IEEE80211_KEYBUF_SIZE	16
     42 #define	IEEE80211_MICBUF_SIZE	(8+8)	/* space for both tx+rx keys */
     43 
     44 /*
     45  * Old WEP-style key.  Deprecated.
     46  */
     47 struct ieee80211_wepkey {
     48 	u_int		wk_len;		/* key length in bytes */
     49 	u_int8_t	wk_key[IEEE80211_KEYBUF_SIZE];
     50 };
     51 
     52 struct ieee80211_cipher;
     53 
     54 /*
     55  * Crypto key state.  There is sufficient room for all supported
     56  * ciphers (see below).  The underlying ciphers are handled
     57  * separately through loadable cipher modules that register with
     58  * the generic crypto support.  A key has a reference to an instance
     59  * of the cipher; any per-key state is hung off wk_private by the
     60  * cipher when it is attached.  Ciphers are automatically called
     61  * to detach and cleanup any such state when the key is deleted.
     62  *
     63  * The generic crypto support handles encap/decap of cipher-related
     64  * frame contents for both hardware- and software-based implementations.
     65  * A key requiring software crypto support is automatically flagged and
     66  * the cipher is expected to honor this and do the necessary work.
     67  * Ciphers such as TKIP may also support mixed hardware/software
     68  * encrypt/decrypt and MIC processing.
     69  */
     70 /* XXX need key index typedef */
     71 /* XXX pack better? */
     72 /* XXX 48-bit rsc/tsc */
     73 struct ieee80211_key {
     74 	u_int8_t	wk_keylen;	/* key length in bytes */
     75 	u_int8_t	wk_flags;
     76 #define	IEEE80211_KEY_XMIT	0x01	/* key used for xmit */
     77 #define	IEEE80211_KEY_RECV	0x02	/* key used for recv */
     78 #define	IEEE80211_KEY_GROUP	0x04	/* key used for WPA group operation */
     79 #define	IEEE80211_KEY_SWCRYPT	0x10	/* host-based encrypt/decrypt */
     80 #define	IEEE80211_KEY_SWMIC	0x20	/* host-based enmic/demic */
     81 	u_int16_t	wk_keyix;	/* key index */
     82 	u_int8_t	wk_key[IEEE80211_KEYBUF_SIZE+IEEE80211_MICBUF_SIZE];
     83 #define	wk_txmic	wk_key+IEEE80211_KEYBUF_SIZE+0	/* XXX can't () right */
     84 #define	wk_rxmic	wk_key+IEEE80211_KEYBUF_SIZE+8	/* XXX can't () right */
     85 	u_int64_t	wk_keyrsc;	/* key receive sequence counter */
     86 	u_int64_t	wk_keytsc;	/* key transmit sequence counter */
     87 	const struct ieee80211_cipher *wk_cipher;
     88 	void		*wk_private;	/* private cipher state */
     89 };
     90 #define	IEEE80211_KEY_COMMON 		/* common flags passed in by apps */\
     91 	(IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV | IEEE80211_KEY_GROUP)
     92 
     93 /*
     94  * NB: these values are ordered carefully; there are lots of
     95  * of implications in any reordering.  In particular beware
     96  * that 4 is not used to avoid conflicting with IEEE80211_F_PRIVACY.
     97  */
     98 #define	IEEE80211_CIPHER_WEP		0
     99 #define	IEEE80211_CIPHER_TKIP		1
    100 #define	IEEE80211_CIPHER_AES_OCB	2
    101 #define	IEEE80211_CIPHER_AES_CCM	3
    102 #define	IEEE80211_CIPHER_CKIP		5
    103 #define	IEEE80211_CIPHER_NONE		6	/* pseudo value */
    104 
    105 #define	IEEE80211_CIPHER_MAX		(IEEE80211_CIPHER_NONE+1)
    106 
    107 #define	IEEE80211_KEYIX_NONE	((u_int16_t) -1)
    108 
    109 #if defined(__KERNEL__) || defined(_KERNEL)
    110 
    111 struct ieee80211com;
    112 struct ieee80211_node;
    113 struct mbuf;
    114 
    115 /*
    116  * Crypto state kept in each ieee80211com.  Some of this
    117  * can/should be shared when virtual AP's are supported.
    118  *
    119  * XXX save reference to ieee80211com to properly encapsulate state.
    120  * XXX split out crypto capabilities from ic_caps
    121  */
    122 struct ieee80211_crypto_state {
    123 	struct ieee80211_key	cs_nw_keys[IEEE80211_WEP_NKID];
    124 	u_int16_t		cs_def_txkey;	/* default/group tx key index */
    125 
    126 	int			(*cs_key_alloc)(struct ieee80211com *,
    127 					const struct ieee80211_key *);
    128 	int			(*cs_key_delete)(struct ieee80211com *,
    129 					const struct ieee80211_key *);
    130 	int			(*cs_key_set)(struct ieee80211com *,
    131 					const struct ieee80211_key *,
    132 					const u_int8_t mac[IEEE80211_ADDR_LEN]);
    133 	void			(*cs_key_update_begin)(struct ieee80211com *);
    134 	void			(*cs_key_update_end)(struct ieee80211com *);
    135 };
    136 
    137 void	ieee80211_crypto_attach(struct ieee80211com *);
    138 void	ieee80211_crypto_detach(struct ieee80211com *);
    139 int	ieee80211_crypto_newkey(struct ieee80211com *,
    140 		int cipher, int flags, struct ieee80211_key *);
    141 int	ieee80211_crypto_delkey(struct ieee80211com *,
    142 		struct ieee80211_key *);
    143 int	ieee80211_crypto_setkey(struct ieee80211com *,
    144 		struct ieee80211_key *, const u_int8_t macaddr[IEEE80211_ADDR_LEN]);
    145 void	ieee80211_crypto_delglobalkeys(struct ieee80211com *);
    146 
    147 /*
    148  * Template for a supported cipher.  Ciphers register with the
    149  * crypto code and are typically loaded as separate modules
    150  * (the null cipher is always present).
    151  * XXX may need refcnts
    152  */
    153 struct ieee80211_cipher {
    154 	const char *ic_name;		/* printable name */
    155 	u_int	ic_cipher;		/* IEEE80211_CIPHER_* */
    156 	u_int	ic_header;		/* size of privacy header (bytes) */
    157 	u_int	ic_trailer;		/* size of privacy trailer (bytes) */
    158 	u_int	ic_miclen;		/* size of mic trailer (bytes) */
    159 	void*	(*ic_attach)(struct ieee80211com *, struct ieee80211_key *);
    160 	void	(*ic_detach)(struct ieee80211_key *);
    161 	int	(*ic_setkey)(struct ieee80211_key *);
    162 	int	(*ic_encap)(struct ieee80211_key *, struct mbuf *,
    163 			u_int8_t keyid);
    164 	int	(*ic_decap)(struct ieee80211_key *, struct mbuf *);
    165 	int	(*ic_enmic)(struct ieee80211_key *, struct mbuf *);
    166 	int	(*ic_demic)(struct ieee80211_key *, struct mbuf *);
    167 };
    168 extern	const struct ieee80211_cipher ieee80211_cipher_none;
    169 extern	const struct ieee80211_cipher ieee80211_cipher_wep;
    170 extern	const struct ieee80211_cipher ieee80211_cipher_tkip;
    171 extern	const struct ieee80211_cipher ieee80211_cipher_ccmp;
    172 
    173 void	ieee80211_crypto_register(const struct ieee80211_cipher *);
    174 void	ieee80211_crypto_unregister(const struct ieee80211_cipher *);
    175 int	ieee80211_crypto_available(u_int cipher);
    176 
    177 struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211com *,
    178 		struct ieee80211_node *, struct mbuf *);
    179 struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211com *,
    180 		struct ieee80211_node *, struct mbuf *);
    181 
    182 /*
    183  * Check and remove any MIC.
    184  */
    185 static __inline int
    186 ieee80211_crypto_demic(struct ieee80211com *ic, struct ieee80211_key *k,
    187 	struct mbuf *m)
    188 {
    189 	const struct ieee80211_cipher *cip = k->wk_cipher;
    190 	return (cip->ic_miclen > 0 ? cip->ic_demic(k, m) : 1);
    191 }
    192 
    193 /*
    194  * Add any MIC.
    195  */
    196 static __inline int
    197 ieee80211_crypto_enmic(struct ieee80211com *ic,
    198 	struct ieee80211_key *k, struct mbuf *m)
    199 {
    200 	const struct ieee80211_cipher *cip = k->wk_cipher;
    201 	return (cip->ic_miclen > 0 ? cip->ic_enmic(k, m) : 1);
    202 }
    203 
    204 /*
    205  * Reset key state to an unused state.  The crypto
    206  * key allocation mechanism insures other state (e.g.
    207  * key data) is properly setup before a key is used.
    208  */
    209 static __inline void
    210 ieee80211_crypto_resetkey(struct ieee80211com *ic,
    211 	struct ieee80211_key *k, u_int16_t ix)
    212 {
    213 	k->wk_cipher = &ieee80211_cipher_none;;
    214 	k->wk_private = k->wk_cipher->ic_attach(ic, k);
    215 	k->wk_keyix = ix;
    216 	k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
    217 }
    218 
    219 /*
    220  * Crypt-related notification methods.
    221  */
    222 void	ieee80211_notify_replay_failure(struct ieee80211com *,
    223 		const struct ieee80211_frame *, const struct ieee80211_key *,
    224 		u_int64_t rsc);
    225 void	ieee80211_notify_michael_failure(struct ieee80211com *,
    226 		const struct ieee80211_frame *, u_int keyix);
    227 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
    228 #endif /* _NET80211_IEEE80211_CRYPTO_H_ */
    229