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 1.9.2.1 2005/09/03 22:40:02 sam Exp $
33  * $DragonFly: src/sys/netproto/802_11/ieee80211_crypto.h,v 1.2 2006/05/18 13:51:46 sephe 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 	uint8_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 typedef uint16_t ieee80211_keyix;	/* h/w key index */
71 
72 struct ieee80211_key {
73 	uint8_t		wk_keylen;	/* key length in bytes */
74 	uint8_t		wk_pad;
75 	uint16_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 	ieee80211_keyix	wk_keyix;	/* h/w key index */
82 	ieee80211_keyix	wk_rxkeyix;	/* optional h/w rx key index */
83 	uint8_t		wk_key[IEEE80211_KEYBUF_SIZE+IEEE80211_MICBUF_SIZE];
84 #define	wk_txmic	wk_key+IEEE80211_KEYBUF_SIZE+0	/* XXX can't () right */
85 #define	wk_rxmic	wk_key+IEEE80211_KEYBUF_SIZE+8	/* XXX can't () right */
86 	uint64_t	wk_keyrsc;	/* key receive sequence counter */
87 	uint64_t	wk_keytsc;	/* key transmit sequence counter */
88 	const struct ieee80211_cipher *wk_cipher;
89 	void		*wk_private;	/* private cipher state */
90 };
91 #define	IEEE80211_KEY_COMMON 		/* common flags passed in by apps */\
92 	(IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV | IEEE80211_KEY_GROUP)
93 
94 /*
95  * NB: these values are ordered carefully; there are lots of
96  * of implications in any reordering.  In particular beware
97  * that 4 is not used to avoid conflicting with IEEE80211_F_PRIVACY.
98  */
99 #define	IEEE80211_CIPHER_WEP		0
100 #define	IEEE80211_CIPHER_TKIP		1
101 #define	IEEE80211_CIPHER_AES_OCB	2
102 #define	IEEE80211_CIPHER_AES_CCM	3
103 #define	IEEE80211_CIPHER_CKIP		5
104 #define	IEEE80211_CIPHER_NONE		6	/* pseudo value */
105 
106 #define	IEEE80211_CIPHER_MAX		(IEEE80211_CIPHER_NONE+1)
107 
108 #define	IEEE80211_KEYIX_NONE	((ieee80211_keyix) -1)
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 	ieee80211_keyix		cs_def_txkey;	/* default/group tx key index */
126 	uint16_t		cs_max_keyix;	/* max h/w key index */
127 
128 	int			(*cs_key_alloc)(struct ieee80211com *,
129 					const struct ieee80211_key *,
130 					ieee80211_keyix *, ieee80211_keyix *);
131 	int			(*cs_key_delete)(struct ieee80211com *,
132 					const struct ieee80211_key *);
133 	int			(*cs_key_set)(struct ieee80211com *,
134 					const struct ieee80211_key *,
135 					const uint8_t mac[IEEE80211_ADDR_LEN]);
136 	void			(*cs_key_update_begin)(struct ieee80211com *);
137 	void			(*cs_key_update_end)(struct ieee80211com *);
138 };
139 
140 void	ieee80211_crypto_attach(struct ieee80211com *);
141 void	ieee80211_crypto_detach(struct ieee80211com *);
142 int	ieee80211_crypto_newkey(struct ieee80211com *,
143 		int cipher, int flags, struct ieee80211_key *);
144 int	ieee80211_crypto_delkey(struct ieee80211com *,
145 		struct ieee80211_key *);
146 int	ieee80211_crypto_setkey(struct ieee80211com *,
147 		struct ieee80211_key *, const uint8_t macaddr[IEEE80211_ADDR_LEN]);
148 void	ieee80211_crypto_delglobalkeys(struct ieee80211com *);
149 
150 /*
151  * Template for a supported cipher.  Ciphers register with the
152  * crypto code and are typically loaded as separate modules
153  * (the null cipher is always present).
154  * XXX may need refcnts
155  */
156 struct ieee80211_cipher {
157 	const char *ic_name;		/* printable name */
158 	u_int	ic_cipher;		/* IEEE80211_CIPHER_* */
159 	u_int	ic_header;		/* size of privacy header (bytes) */
160 	u_int	ic_trailer;		/* size of privacy trailer (bytes) */
161 	u_int	ic_miclen;		/* size of mic trailer (bytes) */
162 	void*	(*ic_attach)(struct ieee80211com *, struct ieee80211_key *);
163 	void	(*ic_detach)(struct ieee80211_key *);
164 	int	(*ic_setkey)(struct ieee80211_key *);
165 	int	(*ic_encap)(struct ieee80211_key *, struct mbuf *,
166 			uint8_t keyid);
167 	int	(*ic_decap)(struct ieee80211_key *, struct mbuf *, int);
168 	int	(*ic_enmic)(struct ieee80211_key *, struct mbuf *, int);
169 	int	(*ic_demic)(struct ieee80211_key *, struct mbuf *, int);
170 };
171 extern	const struct ieee80211_cipher ieee80211_cipher_none;
172 
173 void	ieee80211_crypto_register(const struct ieee80211_cipher *);
174 void	ieee80211_crypto_unregister(const struct ieee80211_cipher *);
175 int	ieee80211_crypto_available(u_int cipher);
176 
177 struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211com *,
178 		struct ieee80211_node *, struct mbuf *);
179 struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211com *,
180 		struct ieee80211_node *, struct mbuf *, int);
181 
182 /*
183  * Check and remove any MIC.
184  */
185 static __inline int
186 ieee80211_crypto_demic(struct ieee80211com *ic, struct ieee80211_key *k,
187 	struct mbuf *m, int force)
188 {
189 	const struct ieee80211_cipher *cip = k->wk_cipher;
190 	return (cip->ic_miclen > 0 ? cip->ic_demic(k, m, force) : 1);
191 }
192 
193 /*
194  * Add any MIC.
195  */
196 static __inline int
197 ieee80211_crypto_enmic(struct ieee80211com *ic,
198 	struct ieee80211_key *k, struct mbuf *m, int force)
199 {
200 	const struct ieee80211_cipher *cip = k->wk_cipher;
201 	return (cip->ic_miclen > 0 ? cip->ic_enmic(k, m, force) : 1);
202 }
203 
204 /*
205  * Reset key state to an unused state.  The crypto
206  * key allocation mechanism insures other state (e.g.
207  * key data) is properly setup before a key is used.
208  */
209 static __inline void
210 ieee80211_crypto_resetkey(struct ieee80211com *ic,
211 	struct ieee80211_key *k, ieee80211_keyix ix)
212 {
213 	k->wk_cipher = &ieee80211_cipher_none;
214 	k->wk_private = k->wk_cipher->ic_attach(ic, k);
215 	k->wk_keyix = k->wk_rxkeyix = ix;
216 	k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
217 }
218 
219 /*
220  * Crypt-related notification methods.
221  */
222 void	ieee80211_notify_replay_failure(struct ieee80211com *,
223 		const struct ieee80211_frame *, const struct ieee80211_key *,
224 		uint64_t rsc);
225 void	ieee80211_notify_michael_failure(struct ieee80211com *,
226 		const struct ieee80211_frame *, u_int keyix);
227 
228 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
229 #endif /* _NET80211_IEEE80211_CRYPTO_H_ */
230