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_NOREPLAY	0x0008	/* ignore replay failures */
82 #define	IEEE80211_KEY_SWENCRYPT	0x0010	/* host-based encrypt */
83 #define	IEEE80211_KEY_SWDECRYPT	0x0020	/* host-based decrypt */
84 #define	IEEE80211_KEY_SWENMIC	0x0040	/* host-based enmic */
85 #define	IEEE80211_KEY_SWDEMIC	0x0080	/* host-based demic */
86 #define	IEEE80211_KEY_DEVKEY	0x0100	/* device key request completed */
87 #define	IEEE80211_KEY_CIPHER0	0x1000	/* cipher-specific action 0 */
88 #define	IEEE80211_KEY_CIPHER1	0x2000	/* cipher-specific action 1 */
89 	ieee80211_keyix	wk_keyix;	/* h/w key index */
90 	ieee80211_keyix	wk_rxkeyix;	/* optional h/w rx key index */
91 	uint8_t		wk_key[IEEE80211_KEYBUF_SIZE+IEEE80211_MICBUF_SIZE];
92 #define	wk_txmic	wk_key+IEEE80211_KEYBUF_SIZE+0	/* XXX can't () right */
93 #define	wk_rxmic	wk_key+IEEE80211_KEYBUF_SIZE+8	/* XXX can't () right */
94 					/* key receive sequence counter */
95 	uint64_t	wk_keyrsc[IEEE80211_TID_SIZE];
96 	uint64_t	wk_keytsc;	/* key transmit sequence counter */
97 	const struct ieee80211_cipher *wk_cipher;
98 	void		*wk_private;	/* private cipher state */
99 	uint8_t		wk_macaddr[IEEE80211_ADDR_LEN];
100 };
101 #define	IEEE80211_KEY_COMMON 		/* common flags passed in by apps */\
102 	(IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV | IEEE80211_KEY_GROUP | \
103 	 IEEE80211_KEY_NOREPLAY)
104 #define	IEEE80211_KEY_DEVICE		/* flags owned by device driver */\
105 	(IEEE80211_KEY_DEVKEY|IEEE80211_KEY_CIPHER0|IEEE80211_KEY_CIPHER1)
106 
107 #define	IEEE80211_KEY_SWCRYPT \
108 	(IEEE80211_KEY_SWENCRYPT | IEEE80211_KEY_SWDECRYPT)
109 #define	IEEE80211_KEY_SWMIC	(IEEE80211_KEY_SWENMIC | IEEE80211_KEY_SWDEMIC)
110 
111 #define	IEEE80211_KEY_BITS \
112 	"\20\1XMIT\2RECV\3GROUP\4SWENCRYPT\5SWDECRYPT\6SWENMIC\7SWDEMIC" \
113 	"\10DEVKEY\11CIPHER0\12CIPHER1"
114 
115 #define	IEEE80211_KEYIX_NONE	((ieee80211_keyix) -1)
116 
117 /*
118  * NB: these values are ordered carefully; there are lots of
119  * of implications in any reordering.  Beware that 4 is used
120  * only to indicate h/w TKIP MIC support in driver capabilities;
121  * there is no separate cipher support (it's rolled into the
122  * TKIP cipher support).
123  */
124 #define	IEEE80211_CIPHER_WEP		0
125 #define	IEEE80211_CIPHER_TKIP		1
126 #define	IEEE80211_CIPHER_AES_OCB	2
127 #define	IEEE80211_CIPHER_AES_CCM	3
128 #define	IEEE80211_CIPHER_TKIPMIC	4	/* TKIP MIC capability */
129 #define	IEEE80211_CIPHER_CKIP		5
130 #define	IEEE80211_CIPHER_NONE		6	/* pseudo value */
131 
132 #define	IEEE80211_CIPHER_MAX		(IEEE80211_CIPHER_NONE+1)
133 
134 /* capability bits in ic_cryptocaps/iv_cryptocaps */
135 #define	IEEE80211_CRYPTO_WEP		(1<<IEEE80211_CIPHER_WEP)
136 #define	IEEE80211_CRYPTO_TKIP		(1<<IEEE80211_CIPHER_TKIP)
137 #define	IEEE80211_CRYPTO_AES_OCB	(1<<IEEE80211_CIPHER_AES_OCB)
138 #define	IEEE80211_CRYPTO_AES_CCM	(1<<IEEE80211_CIPHER_AES_CCM)
139 #define	IEEE80211_CRYPTO_TKIPMIC	(1<<IEEE80211_CIPHER_TKIPMIC)
140 #define	IEEE80211_CRYPTO_CKIP		(1<<IEEE80211_CIPHER_CKIP)
141 
142 #define	IEEE80211_CRYPTO_BITS \
143 	"\20\1WEP\2TKIP\3AES\4AES_CCM\5TKIPMIC\6CKIP"
144 
145 #if defined(__KERNEL__) || defined(_KERNEL)
146 
147 struct ieee80211com;
148 struct ieee80211vap;
149 struct ieee80211_node;
150 struct mbuf;
151 
152 MALLOC_DECLARE(M_80211_CRYPTO);
153 
154 void	ieee80211_crypto_attach(struct ieee80211com *);
155 void	ieee80211_crypto_detach(struct ieee80211com *);
156 void	ieee80211_crypto_vattach(struct ieee80211vap *);
157 void	ieee80211_crypto_vdetach(struct ieee80211vap *);
158 int	ieee80211_crypto_newkey(struct ieee80211vap *,
159 		int cipher, int flags, struct ieee80211_key *);
160 int	ieee80211_crypto_delkey(struct ieee80211vap *,
161 		struct ieee80211_key *);
162 int	ieee80211_crypto_setkey(struct ieee80211vap *, struct ieee80211_key *);
163 void	ieee80211_crypto_delglobalkeys(struct ieee80211vap *);
164 void	ieee80211_crypto_reload_keys(struct ieee80211com *);
165 
166 /*
167  * Template for a supported cipher.  Ciphers register with the
168  * crypto code and are typically loaded as separate modules
169  * (the null cipher is always present).
170  * XXX may need refcnts
171  */
172 struct ieee80211_cipher {
173 	const char *ic_name;		/* printable name */
174 	u_int	ic_cipher;		/* IEEE80211_CIPHER_* */
175 	u_int	ic_header;		/* size of privacy header (bytes) */
176 	u_int	ic_trailer;		/* size of privacy trailer (bytes) */
177 	u_int	ic_miclen;		/* size of mic trailer (bytes) */
178 	void*	(*ic_attach)(struct ieee80211vap *, struct ieee80211_key *);
179 	void	(*ic_detach)(struct ieee80211_key *);
180 	int	(*ic_setkey)(struct ieee80211_key *);
181 	void	(*ic_setiv)(struct ieee80211_key *, uint8_t *);
182 	int	(*ic_encap)(struct ieee80211_key *, struct mbuf *);
183 	int	(*ic_decap)(struct ieee80211_key *, struct mbuf *, int);
184 	int	(*ic_enmic)(struct ieee80211_key *, struct mbuf *, int);
185 	int	(*ic_demic)(struct ieee80211_key *, struct mbuf *, int);
186 };
187 extern	const struct ieee80211_cipher ieee80211_cipher_none;
188 
189 #define	IEEE80211_KEY_UNDEFINED(k) \
190 	((k)->wk_cipher == &ieee80211_cipher_none)
191 
192 void	ieee80211_crypto_register(const struct ieee80211_cipher *);
193 void	ieee80211_crypto_unregister(const struct ieee80211_cipher *);
194 int	ieee80211_crypto_available(u_int cipher);
195 
196 uint8_t	ieee80211_crypto_get_keyid(struct ieee80211vap *vap,
197 		struct ieee80211_key *k);
198 struct ieee80211_key *ieee80211_crypto_get_txkey(struct ieee80211_node *,
199 		struct mbuf *);
200 struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211_node *,
201 		struct mbuf *);
202 struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211_node *,
203 		struct mbuf *, int);
204 
205 /*
206  * Check and remove any MIC.
207  */
208 static __inline int
209 ieee80211_crypto_demic(struct ieee80211vap *vap, struct ieee80211_key *k,
210 	struct mbuf *m, int force)
211 {
212 	const struct ieee80211_cipher *cip = k->wk_cipher;
213 	return (cip->ic_miclen > 0 ? cip->ic_demic(k, m, force) : 1);
214 }
215 
216 /*
217  * Add any MIC.
218  */
219 static __inline int
220 ieee80211_crypto_enmic(struct ieee80211vap *vap,
221 	struct ieee80211_key *k, struct mbuf *m, int force)
222 {
223 	const struct ieee80211_cipher *cip = k->wk_cipher;
224 	return (cip->ic_miclen > 0 ? cip->ic_enmic(k, m, force) : 1);
225 }
226 
227 /*
228  * Reset key state to an unused state.  The crypto
229  * key allocation mechanism insures other state (e.g.
230  * key data) is properly setup before a key is used.
231  */
232 static __inline void
233 ieee80211_crypto_resetkey(struct ieee80211vap *vap,
234 	struct ieee80211_key *k, ieee80211_keyix ix)
235 {
236 	k->wk_cipher = &ieee80211_cipher_none;
237 	k->wk_private = k->wk_cipher->ic_attach(vap, k);
238 	k->wk_keyix = k->wk_rxkeyix = ix;
239 	k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
240 }
241 
242 /*
243  * Crypt-related notification methods.
244  */
245 void	ieee80211_notify_replay_failure(struct ieee80211vap *,
246 		const struct ieee80211_frame *, const struct ieee80211_key *,
247 		uint64_t rsc, int tid);
248 void	ieee80211_notify_michael_failure(struct ieee80211vap *,
249 		const struct ieee80211_frame *, u_int keyix);
250 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
251 #endif /* _NET80211_IEEE80211_CRYPTO_H_ */
252