xref: /freebsd/sys/net80211/ieee80211_crypto.h (revision 6ff6d951ade3f3379932df7f878ef3ea272cfc59)
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	0x01	/* key used for xmit */
79 #define	IEEE80211_KEY_RECV	0x02	/* key used for recv */
80 #define	IEEE80211_KEY_GROUP	0x04	/* key used for WPA group operation */
81 #define	IEEE80211_KEY_SWCRYPT	0x10	/* host-based encrypt/decrypt */
82 #define	IEEE80211_KEY_SWMIC	0x20	/* host-based enmic/demic */
83 	ieee80211_keyix	wk_keyix;	/* h/w key index */
84 	ieee80211_keyix	wk_rxkeyix;	/* optional h/w rx key index */
85 	uint8_t		wk_key[IEEE80211_KEYBUF_SIZE+IEEE80211_MICBUF_SIZE];
86 #define	wk_txmic	wk_key+IEEE80211_KEYBUF_SIZE+0	/* XXX can't () right */
87 #define	wk_rxmic	wk_key+IEEE80211_KEYBUF_SIZE+8	/* XXX can't () right */
88 					/* key receive sequence counter */
89 	uint64_t	wk_keyrsc[IEEE80211_TID_SIZE];
90 	uint64_t	wk_keytsc;	/* key transmit sequence counter */
91 	const struct ieee80211_cipher *wk_cipher;
92 	void		*wk_private;	/* private cipher state */
93 };
94 #define	IEEE80211_KEY_COMMON 		/* common flags passed in by apps */\
95 	(IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV | IEEE80211_KEY_GROUP)
96 
97 #define	IEEE80211_KEYIX_NONE	((ieee80211_keyix) -1)
98 
99 /*
100  * NB: these values are ordered carefully; there are lots of
101  * of implications in any reordering.  Beware that 4 is used
102  * only to indicate h/w TKIP MIC support in driver capabilities;
103  * there is no separate cipher support (it's rolled into the
104  * TKIP cipher support).
105  */
106 #define	IEEE80211_CIPHER_WEP		0
107 #define	IEEE80211_CIPHER_TKIP		1
108 #define	IEEE80211_CIPHER_AES_OCB	2
109 #define	IEEE80211_CIPHER_AES_CCM	3
110 #define	IEEE80211_CIPHER_TKIPMIC	4	/* TKIP MIC capability */
111 #define	IEEE80211_CIPHER_CKIP		5
112 #define	IEEE80211_CIPHER_NONE		6	/* pseudo value */
113 
114 #define	IEEE80211_CIPHER_MAX		(IEEE80211_CIPHER_NONE+1)
115 
116 /* capability bits in ic_cryptocaps/iv_cryptocaps */
117 #define	IEEE80211_CRYPTO_WEP		(1<<IEEE80211_CIPHER_WEP)
118 #define	IEEE80211_CRYPTO_TKIP		(1<<IEEE80211_CIPHER_TKIP)
119 #define	IEEE80211_CRYPTO_AES_OCB	(1<<IEEE80211_CIPHER_AES_OCB)
120 #define	IEEE80211_CRYPTO_AES_CCM	(1<<IEEE80211_CIPHER_AES_CCM)
121 #define	IEEE80211_CRYPTO_TKIPMIC	(1<<IEEE80211_CIPHER_TKIPMIC)
122 #define	IEEE80211_CRYPTO_CKIP		(1<<IEEE80211_CIPHER_CKIP)
123 
124 #if defined(__KERNEL__) || defined(_KERNEL)
125 
126 struct ieee80211com;
127 struct ieee80211vap;
128 struct ieee80211_node;
129 struct mbuf;
130 
131 MALLOC_DECLARE(M_80211_CRYPTO);
132 
133 void	ieee80211_crypto_attach(struct ieee80211com *);
134 void	ieee80211_crypto_detach(struct ieee80211com *);
135 void	ieee80211_crypto_vattach(struct ieee80211vap *);
136 void	ieee80211_crypto_vdetach(struct ieee80211vap *);
137 int	ieee80211_crypto_newkey(struct ieee80211vap *,
138 		int cipher, int flags, struct ieee80211_key *);
139 int	ieee80211_crypto_delkey(struct ieee80211vap *,
140 		struct ieee80211_key *);
141 int	ieee80211_crypto_setkey(struct ieee80211vap *,
142 		struct ieee80211_key *,
143 		const uint8_t macaddr[IEEE80211_ADDR_LEN]);
144 void	ieee80211_crypto_delglobalkeys(struct ieee80211vap *);
145 
146 /*
147  * Template for a supported cipher.  Ciphers register with the
148  * crypto code and are typically loaded as separate modules
149  * (the null cipher is always present).
150  * XXX may need refcnts
151  */
152 struct ieee80211_cipher {
153 	const char *ic_name;		/* printable name */
154 	u_int	ic_cipher;		/* IEEE80211_CIPHER_* */
155 	u_int	ic_header;		/* size of privacy header (bytes) */
156 	u_int	ic_trailer;		/* size of privacy trailer (bytes) */
157 	u_int	ic_miclen;		/* size of mic trailer (bytes) */
158 	void*	(*ic_attach)(struct ieee80211vap *, struct ieee80211_key *);
159 	void	(*ic_detach)(struct ieee80211_key *);
160 	int	(*ic_setkey)(struct ieee80211_key *);
161 	int	(*ic_encap)(struct ieee80211_key *, struct mbuf *,
162 			uint8_t keyid);
163 	int	(*ic_decap)(struct ieee80211_key *, struct mbuf *, int);
164 	int	(*ic_enmic)(struct ieee80211_key *, struct mbuf *, int);
165 	int	(*ic_demic)(struct ieee80211_key *, struct mbuf *, int);
166 };
167 extern	const struct ieee80211_cipher ieee80211_cipher_none;
168 
169 #define	IEEE80211_KEY_UNDEFINED(k) \
170 	((k)->wk_cipher == &ieee80211_cipher_none)
171 
172 void	ieee80211_crypto_register(const struct ieee80211_cipher *);
173 void	ieee80211_crypto_unregister(const struct ieee80211_cipher *);
174 int	ieee80211_crypto_available(u_int cipher);
175 
176 struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211_node *,
177 		struct mbuf *);
178 struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211_node *,
179 		struct mbuf *, int);
180 
181 /*
182  * Check and remove any MIC.
183  */
184 static __inline int
185 ieee80211_crypto_demic(struct ieee80211vap *vap, struct ieee80211_key *k,
186 	struct mbuf *m, int force)
187 {
188 	const struct ieee80211_cipher *cip = k->wk_cipher;
189 	return (cip->ic_miclen > 0 ? cip->ic_demic(k, m, force) : 1);
190 }
191 
192 /*
193  * Add any MIC.
194  */
195 static __inline int
196 ieee80211_crypto_enmic(struct ieee80211vap *vap,
197 	struct ieee80211_key *k, struct mbuf *m, int force)
198 {
199 	const struct ieee80211_cipher *cip = k->wk_cipher;
200 	return (cip->ic_miclen > 0 ? cip->ic_enmic(k, m, force) : 1);
201 }
202 
203 /*
204  * Reset key state to an unused state.  The crypto
205  * key allocation mechanism insures other state (e.g.
206  * key data) is properly setup before a key is used.
207  */
208 static __inline void
209 ieee80211_crypto_resetkey(struct ieee80211vap *vap,
210 	struct ieee80211_key *k, ieee80211_keyix ix)
211 {
212 	k->wk_cipher = &ieee80211_cipher_none;;
213 	k->wk_private = k->wk_cipher->ic_attach(vap, k);
214 	k->wk_keyix = k->wk_rxkeyix = ix;
215 	k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
216 }
217 
218 /*
219  * Crypt-related notification methods.
220  */
221 void	ieee80211_notify_replay_failure(struct ieee80211vap *,
222 		const struct ieee80211_frame *, const struct ieee80211_key *,
223 		uint64_t rsc);
224 void	ieee80211_notify_michael_failure(struct ieee80211vap *,
225 		const struct ieee80211_frame *, u_int keyix);
226 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
227 #endif /* _NET80211_IEEE80211_CRYPTO_H_ */
228