xref: /freebsd/sys/net80211/ieee80211_crypto.h (revision f2831a952d06253dd2a15cf5672342d5cffbcb17)
1 /*-
2  * Copyright (c) 2001 Atsushi Onoe
3  * Copyright (c) 2002-2008 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  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 #ifndef _NET80211_IEEE80211_CRYPTO_H_
29 #define _NET80211_IEEE80211_CRYPTO_H_
30 
31 /*
32  * 802.11 protocol crypto-related definitions.
33  */
34 #define	IEEE80211_KEYBUF_SIZE	16
35 #define	IEEE80211_MICBUF_SIZE	(8+8)	/* space for both tx+rx keys */
36 
37 /*
38  * Old WEP-style key.  Deprecated.
39  */
40 struct ieee80211_wepkey {
41 	u_int		wk_len;		/* key length in bytes */
42 	uint8_t		wk_key[IEEE80211_KEYBUF_SIZE];
43 };
44 
45 struct ieee80211_rsnparms {
46 	uint8_t		rsn_mcastcipher;	/* mcast/group cipher */
47 	uint8_t		rsn_mcastkeylen;	/* mcast key length */
48 	uint8_t		rsn_ucastcipher;	/* selected unicast cipher */
49 	uint8_t		rsn_ucastkeylen;	/* unicast key length */
50 	uint8_t		rsn_keymgmt;		/* selected key mgmt algo */
51 	uint16_t	rsn_caps;		/* capabilities */
52 };
53 
54 struct ieee80211_cipher;
55 
56 /*
57  * Crypto key state.  There is sufficient room for all supported
58  * ciphers (see below).  The underlying ciphers are handled
59  * separately through loadable cipher modules that register with
60  * the generic crypto support.  A key has a reference to an instance
61  * of the cipher; any per-key state is hung off wk_private by the
62  * cipher when it is attached.  Ciphers are automatically called
63  * to detach and cleanup any such state when the key is deleted.
64  *
65  * The generic crypto support handles encap/decap of cipher-related
66  * frame contents for both hardware- and software-based implementations.
67  * A key requiring software crypto support is automatically flagged and
68  * the cipher is expected to honor this and do the necessary work.
69  * Ciphers such as TKIP may also support mixed hardware/software
70  * encrypt/decrypt and MIC processing.
71  */
72 typedef uint16_t ieee80211_keyix;	/* h/w key index */
73 
74 struct ieee80211_key {
75 	uint8_t		wk_keylen;	/* key length in bytes */
76 	uint8_t		wk_pad;
77 	uint16_t	wk_flags;
78 #define	IEEE80211_KEY_XMIT	0x0001	/* key used for xmit */
79 #define	IEEE80211_KEY_RECV	0x0002	/* key used for recv */
80 #define	IEEE80211_KEY_GROUP	0x0004	/* key used for WPA group operation */
81 #define	IEEE80211_KEY_SWENCRYPT	0x0010	/* host-based encrypt */
82 #define	IEEE80211_KEY_SWDECRYPT	0x0020	/* host-based decrypt */
83 #define	IEEE80211_KEY_SWENMIC	0x0040	/* host-based enmic */
84 #define	IEEE80211_KEY_SWDEMIC	0x0080	/* host-based demic */
85 #define	IEEE80211_KEY_DEVKEY	0x0100	/* device key request completed */
86 #define	IEEE80211_KEY_CIPHER0	0x1000	/* cipher-specific action 0 */
87 #define	IEEE80211_KEY_CIPHER1	0x2000	/* cipher-specific action 1 */
88 	ieee80211_keyix	wk_keyix;	/* h/w key index */
89 	ieee80211_keyix	wk_rxkeyix;	/* optional h/w rx key index */
90 	uint8_t		wk_key[IEEE80211_KEYBUF_SIZE+IEEE80211_MICBUF_SIZE];
91 #define	wk_txmic	wk_key+IEEE80211_KEYBUF_SIZE+0	/* XXX can't () right */
92 #define	wk_rxmic	wk_key+IEEE80211_KEYBUF_SIZE+8	/* XXX can't () right */
93 					/* key receive sequence counter */
94 	uint64_t	wk_keyrsc[IEEE80211_TID_SIZE];
95 	uint64_t	wk_keytsc;	/* key transmit sequence counter */
96 	const struct ieee80211_cipher *wk_cipher;
97 	void		*wk_private;	/* private cipher state */
98 	uint8_t		wk_macaddr[IEEE80211_ADDR_LEN];
99 };
100 #define	IEEE80211_KEY_COMMON 		/* common flags passed in by apps */\
101 	(IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV | IEEE80211_KEY_GROUP)
102 
103 #define	IEEE80211_KEY_SWCRYPT \
104 	(IEEE80211_KEY_SWENCRYPT | IEEE80211_KEY_SWDECRYPT)
105 #define	IEEE80211_KEY_SWMIC	(IEEE80211_KEY_SWENMIC | IEEE80211_KEY_SWDEMIC)
106 
107 #define	IEEE80211_KEYIX_NONE	((ieee80211_keyix) -1)
108 
109 /*
110  * NB: these values are ordered carefully; there are lots of
111  * of implications in any reordering.  Beware that 4 is used
112  * only to indicate h/w TKIP MIC support in driver capabilities;
113  * there is no separate cipher support (it's rolled into the
114  * TKIP cipher support).
115  */
116 #define	IEEE80211_CIPHER_WEP		0
117 #define	IEEE80211_CIPHER_TKIP		1
118 #define	IEEE80211_CIPHER_AES_OCB	2
119 #define	IEEE80211_CIPHER_AES_CCM	3
120 #define	IEEE80211_CIPHER_TKIPMIC	4	/* TKIP MIC capability */
121 #define	IEEE80211_CIPHER_CKIP		5
122 #define	IEEE80211_CIPHER_NONE		6	/* pseudo value */
123 
124 #define	IEEE80211_CIPHER_MAX		(IEEE80211_CIPHER_NONE+1)
125 
126 /* capability bits in ic_cryptocaps/iv_cryptocaps */
127 #define	IEEE80211_CRYPTO_WEP		(1<<IEEE80211_CIPHER_WEP)
128 #define	IEEE80211_CRYPTO_TKIP		(1<<IEEE80211_CIPHER_TKIP)
129 #define	IEEE80211_CRYPTO_AES_OCB	(1<<IEEE80211_CIPHER_AES_OCB)
130 #define	IEEE80211_CRYPTO_AES_CCM	(1<<IEEE80211_CIPHER_AES_CCM)
131 #define	IEEE80211_CRYPTO_TKIPMIC	(1<<IEEE80211_CIPHER_TKIPMIC)
132 #define	IEEE80211_CRYPTO_CKIP		(1<<IEEE80211_CIPHER_CKIP)
133 
134 #if defined(__KERNEL__) || defined(_KERNEL)
135 
136 struct ieee80211com;
137 struct ieee80211vap;
138 struct ieee80211_node;
139 struct mbuf;
140 
141 MALLOC_DECLARE(M_80211_CRYPTO);
142 
143 void	ieee80211_crypto_attach(struct ieee80211com *);
144 void	ieee80211_crypto_detach(struct ieee80211com *);
145 void	ieee80211_crypto_vattach(struct ieee80211vap *);
146 void	ieee80211_crypto_vdetach(struct ieee80211vap *);
147 int	ieee80211_crypto_newkey(struct ieee80211vap *,
148 		int cipher, int flags, struct ieee80211_key *);
149 int	ieee80211_crypto_delkey(struct ieee80211vap *,
150 		struct ieee80211_key *);
151 int	ieee80211_crypto_setkey(struct ieee80211vap *, struct ieee80211_key *);
152 void	ieee80211_crypto_delglobalkeys(struct ieee80211vap *);
153 void	ieee80211_crypto_reload_keys(struct ieee80211com *);
154 
155 /*
156  * Template for a supported cipher.  Ciphers register with the
157  * crypto code and are typically loaded as separate modules
158  * (the null cipher is always present).
159  * XXX may need refcnts
160  */
161 struct ieee80211_cipher {
162 	const char *ic_name;		/* printable name */
163 	u_int	ic_cipher;		/* IEEE80211_CIPHER_* */
164 	u_int	ic_header;		/* size of privacy header (bytes) */
165 	u_int	ic_trailer;		/* size of privacy trailer (bytes) */
166 	u_int	ic_miclen;		/* size of mic trailer (bytes) */
167 	void*	(*ic_attach)(struct ieee80211vap *, struct ieee80211_key *);
168 	void	(*ic_detach)(struct ieee80211_key *);
169 	int	(*ic_setkey)(struct ieee80211_key *);
170 	int	(*ic_encap)(struct ieee80211_key *, struct mbuf *,
171 			uint8_t keyid);
172 	int	(*ic_decap)(struct ieee80211_key *, struct mbuf *, int);
173 	int	(*ic_enmic)(struct ieee80211_key *, struct mbuf *, int);
174 	int	(*ic_demic)(struct ieee80211_key *, struct mbuf *, int);
175 };
176 extern	const struct ieee80211_cipher ieee80211_cipher_none;
177 
178 #define	IEEE80211_KEY_UNDEFINED(k) \
179 	((k)->wk_cipher == &ieee80211_cipher_none)
180 
181 void	ieee80211_crypto_register(const struct ieee80211_cipher *);
182 void	ieee80211_crypto_unregister(const struct ieee80211_cipher *);
183 int	ieee80211_crypto_available(u_int cipher);
184 
185 struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211_node *,
186 		struct mbuf *);
187 struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211_node *,
188 		struct mbuf *, int);
189 
190 /*
191  * Check and remove any MIC.
192  */
193 static __inline int
194 ieee80211_crypto_demic(struct ieee80211vap *vap, struct ieee80211_key *k,
195 	struct mbuf *m, int force)
196 {
197 	const struct ieee80211_cipher *cip = k->wk_cipher;
198 	return (cip->ic_miclen > 0 ? cip->ic_demic(k, m, force) : 1);
199 }
200 
201 /*
202  * Add any MIC.
203  */
204 static __inline int
205 ieee80211_crypto_enmic(struct ieee80211vap *vap,
206 	struct ieee80211_key *k, struct mbuf *m, int force)
207 {
208 	const struct ieee80211_cipher *cip = k->wk_cipher;
209 	return (cip->ic_miclen > 0 ? cip->ic_enmic(k, m, force) : 1);
210 }
211 
212 /*
213  * Reset key state to an unused state.  The crypto
214  * key allocation mechanism insures other state (e.g.
215  * key data) is properly setup before a key is used.
216  */
217 static __inline void
218 ieee80211_crypto_resetkey(struct ieee80211vap *vap,
219 	struct ieee80211_key *k, ieee80211_keyix ix)
220 {
221 	k->wk_cipher = &ieee80211_cipher_none;
222 	k->wk_private = k->wk_cipher->ic_attach(vap, k);
223 	k->wk_keyix = k->wk_rxkeyix = ix;
224 	k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
225 }
226 
227 /*
228  * Crypt-related notification methods.
229  */
230 void	ieee80211_notify_replay_failure(struct ieee80211vap *,
231 		const struct ieee80211_frame *, const struct ieee80211_key *,
232 		uint64_t rsc);
233 void	ieee80211_notify_michael_failure(struct ieee80211vap *,
234 		const struct ieee80211_frame *, u_int keyix);
235 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
236 #endif /* _NET80211_IEEE80211_CRYPTO_H_ */
237