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ieee80211_crypto.h revision 1.1.1.3
      1 /*-
      2  * Copyright (c) 2001 Atsushi Onoe
      3  * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
      4  * All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. The name of the author may not be used to endorse or promote products
     15  *    derived from this software without specific prior written permission.
     16  *
     17  * Alternatively, this software may be distributed under the terms of the
     18  * GNU General Public License ("GPL") version 2 as published by the Free
     19  * Software Foundation.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  *
     32  * $FreeBSD: src/sys/net80211/ieee80211_crypto.h,v 1.9 2005/06/10 16:11:24 sam Exp $
     33  */
     34 #ifndef _NET80211_IEEE80211_CRYPTO_H_
     35 #define _NET80211_IEEE80211_CRYPTO_H_
     36 
     37 /*
     38  * 802.11 protocol crypto-related definitions.
     39  */
     40 #define	IEEE80211_KEYBUF_SIZE	16
     41 #define	IEEE80211_MICBUF_SIZE	(8+8)	/* space for both tx+rx keys */
     42 
     43 /*
     44  * Old WEP-style key.  Deprecated.
     45  */
     46 struct ieee80211_wepkey {
     47 	u_int		wk_len;		/* key length in bytes */
     48 	u_int8_t	wk_key[IEEE80211_KEYBUF_SIZE];
     49 };
     50 
     51 struct ieee80211_cipher;
     52 
     53 /*
     54  * Crypto key state.  There is sufficient room for all supported
     55  * ciphers (see below).  The underlying ciphers are handled
     56  * separately through loadable cipher modules that register with
     57  * the generic crypto support.  A key has a reference to an instance
     58  * of the cipher; any per-key state is hung off wk_private by the
     59  * cipher when it is attached.  Ciphers are automatically called
     60  * to detach and cleanup any such state when the key is deleted.
     61  *
     62  * The generic crypto support handles encap/decap of cipher-related
     63  * frame contents for both hardware- and software-based implementations.
     64  * A key requiring software crypto support is automatically flagged and
     65  * the cipher is expected to honor this and do the necessary work.
     66  * Ciphers such as TKIP may also support mixed hardware/software
     67  * encrypt/decrypt and MIC processing.
     68  */
     69 /* XXX need key index typedef */
     70 /* XXX pack better? */
     71 /* XXX 48-bit rsc/tsc */
     72 struct ieee80211_key {
     73 	u_int8_t	wk_keylen;	/* key length in bytes */
     74 	u_int8_t	wk_flags;
     75 #define	IEEE80211_KEY_XMIT	0x01	/* key used for xmit */
     76 #define	IEEE80211_KEY_RECV	0x02	/* key used for recv */
     77 #define	IEEE80211_KEY_GROUP	0x04	/* key used for WPA group operation */
     78 #define	IEEE80211_KEY_SWCRYPT	0x10	/* host-based encrypt/decrypt */
     79 #define	IEEE80211_KEY_SWMIC	0x20	/* host-based enmic/demic */
     80 	u_int16_t	wk_keyix;	/* key index */
     81 	u_int8_t	wk_key[IEEE80211_KEYBUF_SIZE+IEEE80211_MICBUF_SIZE];
     82 #define	wk_txmic	wk_key+IEEE80211_KEYBUF_SIZE+0	/* XXX can't () right */
     83 #define	wk_rxmic	wk_key+IEEE80211_KEYBUF_SIZE+8	/* XXX can't () right */
     84 	u_int64_t	wk_keyrsc;	/* key receive sequence counter */
     85 	u_int64_t	wk_keytsc;	/* key transmit sequence counter */
     86 	const struct ieee80211_cipher *wk_cipher;
     87 	void		*wk_private;	/* private cipher state */
     88 };
     89 #define	IEEE80211_KEY_COMMON 		/* common flags passed in by apps */\
     90 	(IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV | IEEE80211_KEY_GROUP)
     91 
     92 /*
     93  * NB: these values are ordered carefully; there are lots of
     94  * of implications in any reordering.  In particular beware
     95  * that 4 is not used to avoid conflicting with IEEE80211_F_PRIVACY.
     96  */
     97 #define	IEEE80211_CIPHER_WEP		0
     98 #define	IEEE80211_CIPHER_TKIP		1
     99 #define	IEEE80211_CIPHER_AES_OCB	2
    100 #define	IEEE80211_CIPHER_AES_CCM	3
    101 #define	IEEE80211_CIPHER_CKIP		5
    102 #define	IEEE80211_CIPHER_NONE		6	/* pseudo value */
    103 
    104 #define	IEEE80211_CIPHER_MAX		(IEEE80211_CIPHER_NONE+1)
    105 
    106 #define	IEEE80211_KEYIX_NONE	((u_int16_t) -1)
    107 
    108 #if defined(__KERNEL__) || defined(_KERNEL)
    109 
    110 struct ieee80211com;
    111 struct ieee80211_node;
    112 struct mbuf;
    113 
    114 /*
    115  * Crypto state kept in each ieee80211com.  Some of this
    116  * can/should be shared when virtual AP's are supported.
    117  *
    118  * XXX save reference to ieee80211com to properly encapsulate state.
    119  * XXX split out crypto capabilities from ic_caps
    120  */
    121 struct ieee80211_crypto_state {
    122 	struct ieee80211_key	cs_nw_keys[IEEE80211_WEP_NKID];
    123 	u_int16_t		cs_def_txkey;	/* default/group tx key index */
    124 
    125 	int			(*cs_key_alloc)(struct ieee80211com *,
    126 					const struct ieee80211_key *);
    127 	int			(*cs_key_delete)(struct ieee80211com *,
    128 					const struct ieee80211_key *);
    129 	int			(*cs_key_set)(struct ieee80211com *,
    130 					const struct ieee80211_key *,
    131 					const u_int8_t mac[IEEE80211_ADDR_LEN]);
    132 	void			(*cs_key_update_begin)(struct ieee80211com *);
    133 	void			(*cs_key_update_end)(struct ieee80211com *);
    134 };
    135 
    136 void	ieee80211_crypto_attach(struct ieee80211com *);
    137 void	ieee80211_crypto_detach(struct ieee80211com *);
    138 int	ieee80211_crypto_newkey(struct ieee80211com *,
    139 		int cipher, int flags, struct ieee80211_key *);
    140 int	ieee80211_crypto_delkey(struct ieee80211com *,
    141 		struct ieee80211_key *);
    142 int	ieee80211_crypto_setkey(struct ieee80211com *,
    143 		struct ieee80211_key *, const u_int8_t macaddr[IEEE80211_ADDR_LEN]);
    144 void	ieee80211_crypto_delglobalkeys(struct ieee80211com *);
    145 
    146 /*
    147  * Template for a supported cipher.  Ciphers register with the
    148  * crypto code and are typically loaded as separate modules
    149  * (the null cipher is always present).
    150  * XXX may need refcnts
    151  */
    152 struct ieee80211_cipher {
    153 	const char *ic_name;		/* printable name */
    154 	u_int	ic_cipher;		/* IEEE80211_CIPHER_* */
    155 	u_int	ic_header;		/* size of privacy header (bytes) */
    156 	u_int	ic_trailer;		/* size of privacy trailer (bytes) */
    157 	u_int	ic_miclen;		/* size of mic trailer (bytes) */
    158 	void*	(*ic_attach)(struct ieee80211com *, struct ieee80211_key *);
    159 	void	(*ic_detach)(struct ieee80211_key *);
    160 	int	(*ic_setkey)(struct ieee80211_key *);
    161 	int	(*ic_encap)(struct ieee80211_key *, struct mbuf *,
    162 			u_int8_t keyid);
    163 	int	(*ic_decap)(struct ieee80211_key *, struct mbuf *, int);
    164 	int	(*ic_enmic)(struct ieee80211_key *, struct mbuf *, int);
    165 	int	(*ic_demic)(struct ieee80211_key *, struct mbuf *, int);
    166 };
    167 extern	const struct ieee80211_cipher ieee80211_cipher_none;
    168 
    169 void	ieee80211_crypto_register(const struct ieee80211_cipher *);
    170 void	ieee80211_crypto_unregister(const struct ieee80211_cipher *);
    171 int	ieee80211_crypto_available(u_int cipher);
    172 
    173 struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211com *,
    174 		struct ieee80211_node *, struct mbuf *);
    175 struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211com *,
    176 		struct ieee80211_node *, struct mbuf *, int);
    177 
    178 /*
    179  * Check and remove any MIC.
    180  */
    181 static __inline int
    182 ieee80211_crypto_demic(struct ieee80211com *ic, struct ieee80211_key *k,
    183 	struct mbuf *m, int force)
    184 {
    185 	const struct ieee80211_cipher *cip = k->wk_cipher;
    186 	return (cip->ic_miclen > 0 ? cip->ic_demic(k, m, force) : 1);
    187 }
    188 
    189 /*
    190  * Add any MIC.
    191  */
    192 static __inline int
    193 ieee80211_crypto_enmic(struct ieee80211com *ic,
    194 	struct ieee80211_key *k, struct mbuf *m, int force)
    195 {
    196 	const struct ieee80211_cipher *cip = k->wk_cipher;
    197 	return (cip->ic_miclen > 0 ? cip->ic_enmic(k, m, force) : 1);
    198 }
    199 
    200 /*
    201  * Reset key state to an unused state.  The crypto
    202  * key allocation mechanism insures other state (e.g.
    203  * key data) is properly setup before a key is used.
    204  */
    205 static __inline void
    206 ieee80211_crypto_resetkey(struct ieee80211com *ic,
    207 	struct ieee80211_key *k, u_int16_t ix)
    208 {
    209 	k->wk_cipher = &ieee80211_cipher_none;;
    210 	k->wk_private = k->wk_cipher->ic_attach(ic, k);
    211 	k->wk_keyix = ix;
    212 	k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
    213 }
    214 
    215 /*
    216  * Crypt-related notification methods.
    217  */
    218 void	ieee80211_notify_replay_failure(struct ieee80211com *,
    219 		const struct ieee80211_frame *, const struct ieee80211_key *,
    220 		u_int64_t rsc);
    221 void	ieee80211_notify_michael_failure(struct ieee80211com *,
    222 		const struct ieee80211_frame *, u_int keyix);
    223 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
    224 #endif /* _NET80211_IEEE80211_CRYPTO_H_ */
    225