xref: /freebsd/sys/net80211/ieee80211_crypto.h (revision 94942af266ac119ede0ca836f9aa5a5ac0582938)
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  * $FreeBSD$
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 typedef u_int16_t ieee80211_keyix;	/* h/w key index */
70 
71 struct ieee80211_key {
72 	u_int8_t	wk_keylen;	/* key length in bytes */
73 	u_int8_t	wk_pad;
74 	u_int16_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 	ieee80211_keyix	wk_keyix;	/* h/w key index */
81 	ieee80211_keyix	wk_rxkeyix;	/* optional h/w rx 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	((ieee80211_keyix) -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 	ieee80211_keyix		cs_def_txkey;	/* default/group tx key index */
125 	u_int16_t		cs_max_keyix;	/* max h/w key index */
126 
127 	int			(*cs_key_alloc)(struct ieee80211com *,
128 					const struct ieee80211_key *,
129 					ieee80211_keyix *, ieee80211_keyix *);
130 	int			(*cs_key_delete)(struct ieee80211com *,
131 					const struct ieee80211_key *);
132 	int			(*cs_key_set)(struct ieee80211com *,
133 					const struct ieee80211_key *,
134 					const u_int8_t mac[IEEE80211_ADDR_LEN]);
135 	void			(*cs_key_update_begin)(struct ieee80211com *);
136 	void			(*cs_key_update_end)(struct ieee80211com *);
137 };
138 
139 void	ieee80211_crypto_attach(struct ieee80211com *);
140 void	ieee80211_crypto_detach(struct ieee80211com *);
141 int	ieee80211_crypto_newkey(struct ieee80211com *,
142 		int cipher, int flags, struct ieee80211_key *);
143 int	ieee80211_crypto_delkey(struct ieee80211com *,
144 		struct ieee80211_key *);
145 int	ieee80211_crypto_setkey(struct ieee80211com *,
146 		struct ieee80211_key *, const u_int8_t macaddr[IEEE80211_ADDR_LEN]);
147 void	ieee80211_crypto_delglobalkeys(struct ieee80211com *);
148 
149 /*
150  * Template for a supported cipher.  Ciphers register with the
151  * crypto code and are typically loaded as separate modules
152  * (the null cipher is always present).
153  * XXX may need refcnts
154  */
155 struct ieee80211_cipher {
156 	const char *ic_name;		/* printable name */
157 	u_int	ic_cipher;		/* IEEE80211_CIPHER_* */
158 	u_int	ic_header;		/* size of privacy header (bytes) */
159 	u_int	ic_trailer;		/* size of privacy trailer (bytes) */
160 	u_int	ic_miclen;		/* size of mic trailer (bytes) */
161 	void*	(*ic_attach)(struct ieee80211com *, struct ieee80211_key *);
162 	void	(*ic_detach)(struct ieee80211_key *);
163 	int	(*ic_setkey)(struct ieee80211_key *);
164 	int	(*ic_encap)(struct ieee80211_key *, struct mbuf *,
165 			u_int8_t keyid);
166 	int	(*ic_decap)(struct ieee80211_key *, struct mbuf *, int);
167 	int	(*ic_enmic)(struct ieee80211_key *, struct mbuf *, int);
168 	int	(*ic_demic)(struct ieee80211_key *, struct mbuf *, int);
169 };
170 extern	const struct ieee80211_cipher ieee80211_cipher_none;
171 
172 #define	IEEE80211_KEY_UNDEFINED(k) \
173 	((k)->wk_cipher == &ieee80211_cipher_none)
174 
175 void	ieee80211_crypto_register(const struct ieee80211_cipher *);
176 void	ieee80211_crypto_unregister(const struct ieee80211_cipher *);
177 int	ieee80211_crypto_available(u_int cipher);
178 
179 struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211com *,
180 		struct ieee80211_node *, struct mbuf *);
181 struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211com *,
182 		struct ieee80211_node *, struct mbuf *, int);
183 
184 /*
185  * Check and remove any MIC.
186  */
187 static __inline int
188 ieee80211_crypto_demic(struct ieee80211com *ic, struct ieee80211_key *k,
189 	struct mbuf *m, int force)
190 {
191 	const struct ieee80211_cipher *cip = k->wk_cipher;
192 	return (cip->ic_miclen > 0 ? cip->ic_demic(k, m, force) : 1);
193 }
194 
195 /*
196  * Add any MIC.
197  */
198 static __inline int
199 ieee80211_crypto_enmic(struct ieee80211com *ic,
200 	struct ieee80211_key *k, struct mbuf *m, int force)
201 {
202 	const struct ieee80211_cipher *cip = k->wk_cipher;
203 	return (cip->ic_miclen > 0 ? cip->ic_enmic(k, m, force) : 1);
204 }
205 
206 /*
207  * Reset key state to an unused state.  The crypto
208  * key allocation mechanism insures other state (e.g.
209  * key data) is properly setup before a key is used.
210  */
211 static __inline void
212 ieee80211_crypto_resetkey(struct ieee80211com *ic,
213 	struct ieee80211_key *k, ieee80211_keyix ix)
214 {
215 	k->wk_cipher = &ieee80211_cipher_none;;
216 	k->wk_private = k->wk_cipher->ic_attach(ic, k);
217 	k->wk_keyix = k->wk_rxkeyix = ix;
218 	k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
219 }
220 
221 /*
222  * Crypt-related notification methods.
223  */
224 void	ieee80211_notify_replay_failure(struct ieee80211com *,
225 		const struct ieee80211_frame *, const struct ieee80211_key *,
226 		u_int64_t rsc);
227 void	ieee80211_notify_michael_failure(struct ieee80211com *,
228 		const struct ieee80211_frame *, u_int keyix);
229 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
230 #endif /* _NET80211_IEEE80211_CRYPTO_H_ */
231