ieee80211_crypto.h revision 1.2.4.5 1 /* $NetBSD: ieee80211_crypto.h,v 1.2.4.5 2005/11/10 14:10:51 skrll Exp $ */
2 /*-
3 * Copyright (c) 2001 Atsushi Onoe
4 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * Alternatively, this software may be distributed under the terms of the
19 * GNU General Public License ("GPL") version 2 as published by the Free
20 * Software Foundation.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 *
33 * $FreeBSD: src/sys/net80211/ieee80211_crypto.h,v 1.9 2005/06/10 16:11:24 sam 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 u_int8_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 /* XXX need key index typedef */
71 /* XXX pack better? */
72 /* XXX 48-bit rsc/tsc */
73 struct ieee80211_key {
74 u_int8_t wk_keylen; /* key length in bytes */
75 u_int8_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 u_int16_t wk_keyix; /* key index */
82 u_int8_t wk_key[IEEE80211_KEYBUF_SIZE+IEEE80211_MICBUF_SIZE];
83 #define wk_txmic wk_key+IEEE80211_KEYBUF_SIZE+0 /* XXX can't () right */
84 #define wk_rxmic wk_key+IEEE80211_KEYBUF_SIZE+8 /* XXX can't () right */
85 u_int64_t wk_keyrsc; /* key receive sequence counter */
86 u_int64_t wk_keytsc; /* key transmit sequence counter */
87 const struct ieee80211_cipher *wk_cipher;
88 void *wk_private; /* private cipher state */
89 };
90 #define IEEE80211_KEY_COMMON /* common flags passed in by apps */\
91 (IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV | IEEE80211_KEY_GROUP)
92
93 /*
94 * NB: these values are ordered carefully; there are lots of
95 * of implications in any reordering. In particular beware
96 * that 4 is not used to avoid conflicting with IEEE80211_F_PRIVACY.
97 */
98 #define IEEE80211_CIPHER_WEP 0
99 #define IEEE80211_CIPHER_TKIP 1
100 #define IEEE80211_CIPHER_AES_OCB 2
101 #define IEEE80211_CIPHER_AES_CCM 3
102 #define IEEE80211_CIPHER_CKIP 5
103 #define IEEE80211_CIPHER_NONE 6 /* pseudo value */
104
105 #define IEEE80211_CIPHER_MAX (IEEE80211_CIPHER_NONE+1)
106
107 #define IEEE80211_KEYIX_NONE ((u_int16_t) -1)
108 #define IEEE80211_KEY_UNDEFINED(k) ((k).wk_cipher == &ieee80211_cipher_none)
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 u_int16_t cs_def_txkey; /* default/group tx key index */
126
127 int (*cs_key_alloc)(struct ieee80211com *,
128 const struct ieee80211_key *);
129 int (*cs_key_delete)(struct ieee80211com *,
130 const struct ieee80211_key *);
131 int (*cs_key_set)(struct ieee80211com *,
132 const struct ieee80211_key *,
133 const u_int8_t mac[IEEE80211_ADDR_LEN]);
134 void (*cs_key_update_begin)(struct ieee80211com *);
135 void (*cs_key_update_end)(struct ieee80211com *);
136 };
137
138 void ieee80211_crypto_attach(struct ieee80211com *);
139 void ieee80211_crypto_detach(struct ieee80211com *);
140 int ieee80211_crypto_newkey(struct ieee80211com *,
141 int cipher, int flags, struct ieee80211_key *);
142 int ieee80211_crypto_delkey(struct ieee80211com *,
143 struct ieee80211_key *);
144 int ieee80211_crypto_setkey(struct ieee80211com *,
145 struct ieee80211_key *, const u_int8_t macaddr[IEEE80211_ADDR_LEN]);
146 void ieee80211_crypto_delglobalkeys(struct ieee80211com *);
147
148 /*
149 * Template for a supported cipher. Ciphers register with the
150 * crypto code and are typically loaded as separate modules
151 * (the null cipher is always present).
152 * XXX may need refcnts
153 */
154 struct ieee80211_cipher {
155 const char *ic_name; /* printable name */
156 u_int ic_cipher; /* IEEE80211_CIPHER_* */
157 u_int ic_header; /* size of privacy header (bytes) */
158 u_int ic_trailer; /* size of privacy trailer (bytes) */
159 u_int ic_miclen; /* size of mic trailer (bytes) */
160 void* (*ic_attach)(struct ieee80211com *, struct ieee80211_key *);
161 void (*ic_detach)(struct ieee80211_key *);
162 int (*ic_setkey)(struct ieee80211_key *);
163 int (*ic_encap)(struct ieee80211_key *, struct mbuf *,
164 u_int8_t keyid);
165 int (*ic_decap)(struct ieee80211_key *, struct mbuf *, int);
166 int (*ic_enmic)(struct ieee80211_key *, struct mbuf *, int);
167 int (*ic_demic)(struct ieee80211_key *, struct mbuf *, int);
168 };
169 extern const struct ieee80211_cipher ieee80211_cipher_none;
170 extern const struct ieee80211_cipher ieee80211_cipher_wep;
171 extern const struct ieee80211_cipher ieee80211_cipher_tkip;
172 extern const struct ieee80211_cipher ieee80211_cipher_ccmp;
173
174 void ieee80211_crypto_register(const struct ieee80211_cipher *);
175 void ieee80211_crypto_unregister(const struct ieee80211_cipher *);
176 int ieee80211_crypto_available(u_int cipher);
177
178 struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211com *,
179 struct ieee80211_node *, struct mbuf *);
180 struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211com *,
181 struct ieee80211_node *, struct mbuf *, int);
182
183 /*
184 * Check and remove any MIC.
185 */
186 static __inline int
187 ieee80211_crypto_demic(struct ieee80211com *ic, struct ieee80211_key *k,
188 struct mbuf *m, int force)
189 {
190 const struct ieee80211_cipher *cip = k->wk_cipher;
191 return (cip->ic_miclen > 0 ? cip->ic_demic(k, m, force) : 1);
192 }
193
194 /*
195 * Add any MIC.
196 */
197 static __inline int
198 ieee80211_crypto_enmic(struct ieee80211com *ic,
199 struct ieee80211_key *k, struct mbuf *m, int force)
200 {
201 const struct ieee80211_cipher *cip = k->wk_cipher;
202 return (cip->ic_miclen > 0 ? cip->ic_enmic(k, m, force) : 1);
203 }
204
205 /*
206 * Reset key state to an unused state. The crypto
207 * key allocation mechanism insures other state (e.g.
208 * key data) is properly setup before a key is used.
209 */
210 static __inline void
211 ieee80211_crypto_resetkey(struct ieee80211com *ic,
212 struct ieee80211_key *k, u_int16_t ix)
213 {
214 k->wk_cipher = &ieee80211_cipher_none;;
215 k->wk_private = k->wk_cipher->ic_attach(ic, k);
216 k->wk_keyix = ix;
217 k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
218 }
219
220 /*
221 * Crypt-related notification methods.
222 */
223 void ieee80211_notify_replay_failure(struct ieee80211com *,
224 const struct ieee80211_frame *, const struct ieee80211_key *,
225 u_int64_t rsc);
226 void ieee80211_notify_michael_failure(struct ieee80211com *,
227 const struct ieee80211_frame *, u_int keyix);
228 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
229 #endif /* _NET80211_IEEE80211_CRYPTO_H_ */
230