ieee80211_crypto.h revision 1.1.1.2 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 1.7 2005/04/12 17:55:13 sam Exp $
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 /* XXX need key index typedef */
70 /* XXX pack better? */
71 /* XXX 48-bit rsc/tsc */
72 struct ieee80211_key {
73 u_int8_t wk_keylen; /* key length in bytes */
74 u_int8_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 u_int16_t wk_keyix; /* key index */
81 u_int8_t wk_key[IEEE80211_KEYBUF_SIZE+IEEE80211_MICBUF_SIZE];
82 #define wk_txmic wk_key+IEEE80211_KEYBUF_SIZE+0 /* XXX can't () right */
83 #define wk_rxmic wk_key+IEEE80211_KEYBUF_SIZE+8 /* XXX can't () right */
84 u_int64_t wk_keyrsc; /* key receive sequence counter */
85 u_int64_t wk_keytsc; /* key transmit sequence counter */
86 const struct ieee80211_cipher *wk_cipher;
87 void *wk_private; /* private cipher state */
88 };
89 #define IEEE80211_KEY_COMMON /* common flags passed in by apps */\
90 (IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV | IEEE80211_KEY_GROUP)
91
92 /*
93 * NB: these values are ordered carefully; there are lots of
94 * of implications in any reordering. In particular beware
95 * that 4 is not used to avoid conflicting with IEEE80211_F_PRIVACY.
96 */
97 #define IEEE80211_CIPHER_WEP 0
98 #define IEEE80211_CIPHER_TKIP 1
99 #define IEEE80211_CIPHER_AES_OCB 2
100 #define IEEE80211_CIPHER_AES_CCM 3
101 #define IEEE80211_CIPHER_CKIP 5
102 #define IEEE80211_CIPHER_NONE 6 /* pseudo value */
103
104 #define IEEE80211_CIPHER_MAX (IEEE80211_CIPHER_NONE+1)
105
106 #define IEEE80211_KEYIX_NONE ((u_int16_t) -1)
107
108 #if defined(__KERNEL__) || defined(_KERNEL)
109
110 struct ieee80211com;
111 struct ieee80211_node;
112 struct mbuf;
113
114 /*
115 * Crypto state kept in each ieee80211com. Some of this
116 * can/should be shared when virtual AP's are supported.
117 *
118 * XXX save reference to ieee80211com to properly encapsulate state.
119 * XXX split out crypto capabilities from ic_caps
120 */
121 struct ieee80211_crypto_state {
122 struct ieee80211_key cs_nw_keys[IEEE80211_WEP_NKID];
123 u_int16_t cs_def_txkey; /* default/group tx key index */
124
125 int (*cs_key_alloc)(struct ieee80211com *,
126 const struct ieee80211_key *);
127 int (*cs_key_delete)(struct ieee80211com *,
128 const struct ieee80211_key *);
129 int (*cs_key_set)(struct ieee80211com *,
130 const struct ieee80211_key *,
131 const u_int8_t mac[IEEE80211_ADDR_LEN]);
132 void (*cs_key_update_begin)(struct ieee80211com *);
133 void (*cs_key_update_end)(struct ieee80211com *);
134 };
135
136 void ieee80211_crypto_attach(struct ieee80211com *);
137 void ieee80211_crypto_detach(struct ieee80211com *);
138 int ieee80211_crypto_newkey(struct ieee80211com *,
139 int cipher, int flags, struct ieee80211_key *);
140 int ieee80211_crypto_delkey(struct ieee80211com *,
141 struct ieee80211_key *);
142 int ieee80211_crypto_setkey(struct ieee80211com *,
143 struct ieee80211_key *, const u_int8_t macaddr[IEEE80211_ADDR_LEN]);
144 void ieee80211_crypto_delglobalkeys(struct ieee80211com *);
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 ieee80211com *, 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 u_int8_t keyid);
163 int (*ic_decap)(struct ieee80211_key *, struct mbuf *);
164 int (*ic_enmic)(struct ieee80211_key *, struct mbuf *);
165 int (*ic_demic)(struct ieee80211_key *, struct mbuf *);
166 };
167 extern const struct ieee80211_cipher ieee80211_cipher_none;
168
169 void ieee80211_crypto_register(const struct ieee80211_cipher *);
170 void ieee80211_crypto_unregister(const struct ieee80211_cipher *);
171 int ieee80211_crypto_available(u_int cipher);
172
173 struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211com *,
174 struct ieee80211_node *, struct mbuf *);
175 struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211com *,
176 struct ieee80211_node *, struct mbuf *);
177
178 /*
179 * Check and remove any MIC.
180 */
181 static __inline int
182 ieee80211_crypto_demic(struct ieee80211com *ic, struct ieee80211_key *k,
183 struct mbuf *m)
184 {
185 const struct ieee80211_cipher *cip = k->wk_cipher;
186 return (cip->ic_miclen > 0 ? cip->ic_demic(k, m) : 1);
187 }
188
189 /*
190 * Add any MIC.
191 */
192 static __inline int
193 ieee80211_crypto_enmic(struct ieee80211com *ic,
194 struct ieee80211_key *k, struct mbuf *m)
195 {
196 const struct ieee80211_cipher *cip = k->wk_cipher;
197 return (cip->ic_miclen > 0 ? cip->ic_enmic(k, m) : 1);
198 }
199
200 /*
201 * Reset key state to an unused state. The crypto
202 * key allocation mechanism insures other state (e.g.
203 * key data) is properly setup before a key is used.
204 */
205 static __inline void
206 ieee80211_crypto_resetkey(struct ieee80211com *ic,
207 struct ieee80211_key *k, u_int16_t ix)
208 {
209 k->wk_cipher = &ieee80211_cipher_none;;
210 k->wk_private = k->wk_cipher->ic_attach(ic, k);
211 k->wk_keyix = ix;
212 k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
213 }
214
215 /*
216 * Crypt-related notification methods.
217 */
218 void ieee80211_notify_replay_failure(struct ieee80211com *,
219 const struct ieee80211_frame *, const struct ieee80211_key *,
220 u_int64_t rsc);
221 void ieee80211_notify_michael_failure(struct ieee80211com *,
222 const struct ieee80211_frame *, u_int keyix);
223 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
224 #endif /* _NET80211_IEEE80211_CRYPTO_H_ */
225