xref: /netbsd-src/sys/net80211/ieee80211_crypto.h (revision 8a5e2a50be13e77dd4df5daf258ddceeeeb47ce6)
1 /*	$NetBSD: ieee80211_crypto.h,v 1.6 2005/07/26 22:57:26 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 1.9 2005/06/10 16:11:24 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 #define	IEEE80211_KEY_UNDEFINED(k)	((k).wk_cipher == &ieee80211_cipher_none)
109 
110 #if defined(__KERNEL__) || defined(_KERNEL)
111 
112 struct ieee80211com;
113 struct ieee80211_node;
114 struct mbuf;
115 
116 /*
117  * Crypto state kept in each ieee80211com.  Some of this
118  * can/should be shared when virtual AP's are supported.
119  *
120  * XXX save reference to ieee80211com to properly encapsulate state.
121  * XXX split out crypto capabilities from ic_caps
122  */
123 struct ieee80211_crypto_state {
124 	struct ieee80211_key	cs_nw_keys[IEEE80211_WEP_NKID];
125 	u_int16_t		cs_def_txkey;	/* default/group tx key index */
126 
127 	int			(*cs_key_alloc)(struct ieee80211com *,
128 					const struct ieee80211_key *);
129 	int			(*cs_key_delete)(struct ieee80211com *,
130 					const struct ieee80211_key *);
131 	int			(*cs_key_set)(struct ieee80211com *,
132 					const struct ieee80211_key *,
133 					const u_int8_t mac[IEEE80211_ADDR_LEN]);
134 	void			(*cs_key_update_begin)(struct ieee80211com *);
135 	void			(*cs_key_update_end)(struct ieee80211com *);
136 };
137 
138 void	ieee80211_crypto_attach(struct ieee80211com *);
139 void	ieee80211_crypto_detach(struct ieee80211com *);
140 int	ieee80211_crypto_newkey(struct ieee80211com *,
141 		int cipher, int flags, struct ieee80211_key *);
142 int	ieee80211_crypto_delkey(struct ieee80211com *,
143 		struct ieee80211_key *);
144 int	ieee80211_crypto_setkey(struct ieee80211com *,
145 		struct ieee80211_key *, const u_int8_t macaddr[IEEE80211_ADDR_LEN]);
146 void	ieee80211_crypto_delglobalkeys(struct ieee80211com *);
147 
148 /*
149  * Template for a supported cipher.  Ciphers register with the
150  * crypto code and are typically loaded as separate modules
151  * (the null cipher is always present).
152  * XXX may need refcnts
153  */
154 struct ieee80211_cipher {
155 	const char *ic_name;		/* printable name */
156 	u_int	ic_cipher;		/* IEEE80211_CIPHER_* */
157 	u_int	ic_header;		/* size of privacy header (bytes) */
158 	u_int	ic_trailer;		/* size of privacy trailer (bytes) */
159 	u_int	ic_miclen;		/* size of mic trailer (bytes) */
160 	void*	(*ic_attach)(struct ieee80211com *, struct ieee80211_key *);
161 	void	(*ic_detach)(struct ieee80211_key *);
162 	int	(*ic_setkey)(struct ieee80211_key *);
163 	int	(*ic_encap)(struct ieee80211_key *, struct mbuf *,
164 			u_int8_t keyid);
165 	int	(*ic_decap)(struct ieee80211_key *, struct mbuf *, int);
166 	int	(*ic_enmic)(struct ieee80211_key *, struct mbuf *, int);
167 	int	(*ic_demic)(struct ieee80211_key *, struct mbuf *, int);
168 };
169 extern	const struct ieee80211_cipher ieee80211_cipher_none;
170 extern	const struct ieee80211_cipher ieee80211_cipher_wep;
171 extern	const struct ieee80211_cipher ieee80211_cipher_tkip;
172 extern	const struct ieee80211_cipher ieee80211_cipher_ccmp;
173 
174 void	ieee80211_crypto_register(const struct ieee80211_cipher *);
175 void	ieee80211_crypto_unregister(const struct ieee80211_cipher *);
176 int	ieee80211_crypto_available(u_int cipher);
177 
178 struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211com *,
179 		struct ieee80211_node *, struct mbuf *);
180 struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211com *,
181 		struct ieee80211_node *, struct mbuf *, int);
182 
183 /*
184  * Check and remove any MIC.
185  */
186 static __inline int
187 ieee80211_crypto_demic(struct ieee80211com *ic, struct ieee80211_key *k,
188 	struct mbuf *m, int force)
189 {
190 	const struct ieee80211_cipher *cip = k->wk_cipher;
191 	return (cip->ic_miclen > 0 ? cip->ic_demic(k, m, force) : 1);
192 }
193 
194 /*
195  * Add any MIC.
196  */
197 static __inline int
198 ieee80211_crypto_enmic(struct ieee80211com *ic,
199 	struct ieee80211_key *k, struct mbuf *m, int force)
200 {
201 	const struct ieee80211_cipher *cip = k->wk_cipher;
202 	return (cip->ic_miclen > 0 ? cip->ic_enmic(k, m, force) : 1);
203 }
204 
205 /*
206  * Reset key state to an unused state.  The crypto
207  * key allocation mechanism insures other state (e.g.
208  * key data) is properly setup before a key is used.
209  */
210 static __inline void
211 ieee80211_crypto_resetkey(struct ieee80211com *ic,
212 	struct ieee80211_key *k, u_int16_t ix)
213 {
214 	k->wk_cipher = &ieee80211_cipher_none;;
215 	k->wk_private = k->wk_cipher->ic_attach(ic, k);
216 	k->wk_keyix = ix;
217 	k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
218 }
219 
220 /*
221  * Crypt-related notification methods.
222  */
223 void	ieee80211_notify_replay_failure(struct ieee80211com *,
224 		const struct ieee80211_frame *, const struct ieee80211_key *,
225 		u_int64_t rsc);
226 void	ieee80211_notify_michael_failure(struct ieee80211com *,
227 		const struct ieee80211_frame *, u_int keyix);
228 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
229 #endif /* _NET80211_IEEE80211_CRYPTO_H_ */
230