sys/net80211/ieee80211_crypto.h

   1 /*      $NetBSD: ieee80211_crypto.h,v 1.11 2009/01/03 03:43:23 yamt 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 1.10 2005/08/08 18:46:35 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 typedef u_int16_t ieee80211_keyix;      /* h/w key index */
  71
  72 struct ieee80211_key {
  73         u_int8_t        wk_keylen;      /* key length in bytes */
  74         u_int8_t        wk_pad;
  75         u_int16_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         u_int8_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         u_int64_t       wk_keyrsc;      /* key receive sequence counter */
  87         u_int64_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 #define IEEE80211_KEY_UNDEFINED(k)      ((k).wk_cipher == &ieee80211_cipher_none)
 110
 111 #if defined(__KERNEL__) || defined(_KERNEL)
 112
 113 struct ieee80211com;
 114 struct ieee80211_node;
 115 struct mbuf;
 116
 117 /*
 118  * Crypto state kept in each ieee80211com.  Some of this
 119  * can/should be shared when virtual AP's are supported.
 120  *
 121  * XXX save reference to ieee80211com to properly encapsulate state.
 122  * XXX split out crypto capabilities from ic_caps
 123  */
 124 struct ieee80211_crypto_state {
 125         struct ieee80211_key    cs_nw_keys[IEEE80211_WEP_NKID];
 126         ieee80211_keyix         cs_def_txkey;   /* default/group tx key index */
 127         u_int16_t               cs_max_keyix;   /* max h/w key index */
 128
 129         int                     (*cs_key_alloc)(struct ieee80211com *,
 130                                         const struct ieee80211_key *,
 131                                         ieee80211_keyix *, ieee80211_keyix *);
 132         int                     (*cs_key_delete)(struct ieee80211com *,
 133                                         const struct ieee80211_key *);
 134         int                     (*cs_key_set)(struct ieee80211com *,
 135                                         const struct ieee80211_key *,
 136                                         const u_int8_t mac[IEEE80211_ADDR_LEN]);
 137         void                    (*cs_key_update_begin)(struct ieee80211com *);
 138         void                    (*cs_key_update_end)(struct ieee80211com *);
 139 };
 140
 141 void    ieee80211_crypto_attach(struct ieee80211com *);
 142 void    ieee80211_crypto_detach(struct ieee80211com *);
 143 int     ieee80211_crypto_newkey(struct ieee80211com *,
 144                 int cipher, int flags, struct ieee80211_key *);
 145 int     ieee80211_crypto_delkey(struct ieee80211com *,
 146                 struct ieee80211_key *);
 147 int     ieee80211_crypto_setkey(struct ieee80211com *,
 148                 struct ieee80211_key *, const u_int8_t macaddr[IEEE80211_ADDR_LEN]);
 149 void    ieee80211_crypto_delglobalkeys(struct ieee80211com *);
 150
 151 /*
 152  * Template for a supported cipher.  Ciphers register with the
 153  * crypto code and are typically loaded as separate modules
 154  * (the null cipher is always present).
 155  * XXX may need refcnts
 156  */
 157 struct ieee80211_cipher {
 158         const char *ic_name;            /* printable name */
 159         u_int   ic_cipher;              /* IEEE80211_CIPHER_* */
 160         u_int   ic_header;              /* size of privacy header (bytes) */
 161         u_int   ic_trailer;             /* size of privacy trailer (bytes) */
 162         u_int   ic_miclen;              /* size of mic trailer (bytes) */
 163         void*   (*ic_attach)(struct ieee80211com *, struct ieee80211_key *);
 164         void    (*ic_detach)(struct ieee80211_key *);
 165         int     (*ic_setkey)(struct ieee80211_key *);
 166         int     (*ic_encap)(struct ieee80211_key *, struct mbuf *,
 167                         u_int8_t keyid);
 168         int     (*ic_decap)(struct ieee80211_key *, struct mbuf *, int);
 169         int     (*ic_enmic)(struct ieee80211_key *, struct mbuf *, int);
 170         int     (*ic_demic)(struct ieee80211_key *, struct mbuf *, int);
 171 };
 172 extern  const struct ieee80211_cipher ieee80211_cipher_none;
 173 extern  const struct ieee80211_cipher ieee80211_cipher_wep;
 174 extern  const struct ieee80211_cipher ieee80211_cipher_tkip;
 175 extern  const struct ieee80211_cipher ieee80211_cipher_ccmp;
 176
 177 void    ieee80211_crypto_register(const struct ieee80211_cipher *);
 178 void    ieee80211_crypto_unregister(const struct ieee80211_cipher *);
 179 int     ieee80211_crypto_available(u_int cipher);
 180
 181 struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211com *,
 182                 struct ieee80211_node *, struct mbuf *);
 183 struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211com *,
 184                 struct ieee80211_node *, struct mbuf *, int);
 185
 186 /*
 187  * Check and remove any MIC.
 188  */
 189 static __inline int
 190 ieee80211_crypto_demic(struct ieee80211com *ic,
 191     struct ieee80211_key *k, struct mbuf *m, int force)
 192 {
 193         const struct ieee80211_cipher *cip = k->wk_cipher;
 194         return (cip->ic_miclen > 0 ? cip->ic_demic(k, m, force) : 1);
 195 }
 196
 197 /*
 198  * Add any MIC.
 199  */
 200 static __inline int
 201 ieee80211_crypto_enmic(struct ieee80211com *ic,
 202         struct ieee80211_key *k, struct mbuf *m, int force)
 203 {
 204         const struct ieee80211_cipher *cip = k->wk_cipher;
 205         return (cip->ic_miclen > 0 ? cip->ic_enmic(k, m, force) : 1);
 206 }
 207
 208 /*
 209  * Reset key state to an unused state.  The crypto
 210  * key allocation mechanism insures other state (e.g.
 211  * key data) is properly setup before a key is used.
 212  */
 213 static __inline void
 214 ieee80211_crypto_resetkey(struct ieee80211com *ic,
 215         struct ieee80211_key *k, ieee80211_keyix ix)
 216 {
 217         k->wk_cipher = &ieee80211_cipher_none;
 218         k->wk_private = k->wk_cipher->ic_attach(ic, k);
 219         k->wk_keyix = k->wk_rxkeyix = ix;
 220         k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
 221 }
 222
 223 /*
 224  * Crypt-related notification methods.
 225  */
 226 void    ieee80211_notify_replay_failure(struct ieee80211com *,
 227                 const struct ieee80211_frame *, const struct ieee80211_key *,
 228                 u_int64_t rsc);
 229 void    ieee80211_notify_michael_failure(struct ieee80211com *,
 230                 const struct ieee80211_frame *, u_int keyix);
 231 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
 232 #endif /* !_NET80211_IEEE80211_CRYPTO_H_ */