/*      $NetBSD: ieee80211_crypto.h,v 1.12 2017/12/10 08:56:23 maxv Exp $       */
/*-
 * Copyright (c) 2001 Atsushi Onoe
 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * $FreeBSD: src/sys/net80211/ieee80211_crypto.h,v 1.10 2005/08/08 18:46:35 sam Exp $
 */
#ifndef _NET80211_IEEE80211_CRYPTO_H_
#define _NET80211_IEEE80211_CRYPTO_H_

/*
 * 802.11 protocol crypto-related definitions.
 */
#define IEEE80211_KEYBUF_SIZE   16
#define IEEE80211_MICBUF_SIZE   (8+8)   /* space for both tx+rx keys */

/*
 * Old WEP-style key.  Deprecated.
 */
struct ieee80211_wepkey {
        u_int           wk_len;         /* key length in bytes */
        u_int8_t        wk_key[IEEE80211_KEYBUF_SIZE];
};

struct ieee80211_cipher;

/*
 * Crypto key state.  There is sufficient room for all supported
 * ciphers (see below).  The underlying ciphers are handled
 * separately through loadable cipher modules that register with
 * the generic crypto support.  A key has a reference to an instance
 * of the cipher; any per-key state is hung off wk_private by the
 * cipher when it is attached.  Ciphers are automatically called
 * to detach and cleanup any such state when the key is deleted.
 *
 * The generic crypto support handles encap/decap of cipher-related
 * frame contents for both hardware- and software-based implementations.
 * A key requiring software crypto support is automatically flagged and
 * the cipher is expected to honor this and do the necessary work.
 * Ciphers such as TKIP may also support mixed hardware/software
 * encrypt/decrypt and MIC processing.
 */
typedef u_int16_t ieee80211_keyix;      /* h/w key index */

struct ieee80211_key {
        u_int8_t        wk_keylen;      /* key length in bytes */
        u_int8_t        wk_pad;
        u_int16_t       wk_flags;
#define IEEE80211_KEY_XMIT      0x01    /* key used for xmit */
#define IEEE80211_KEY_RECV      0x02    /* key used for recv */
#define IEEE80211_KEY_GROUP     0x04    /* key used for WPA group operation */
#define IEEE80211_KEY_SWCRYPT   0x10    /* host-based encrypt/decrypt */
#define IEEE80211_KEY_SWMIC     0x20    /* host-based enmic/demic */
        ieee80211_keyix wk_keyix;       /* h/w key index */
        ieee80211_keyix wk_rxkeyix;     /* optional h/w rx key index */
        u_int8_t        wk_key[IEEE80211_KEYBUF_SIZE+IEEE80211_MICBUF_SIZE];
#define wk_txmic        wk_key+IEEE80211_KEYBUF_SIZE+0  /* XXX can't () right */
#define wk_rxmic        wk_key+IEEE80211_KEYBUF_SIZE+8  /* XXX can't () right */
        u_int64_t       wk_keyrsc;      /* key receive sequence counter */
        u_int64_t       wk_keytsc;      /* key transmit sequence counter */
        const struct ieee80211_cipher *wk_cipher;
        void            *wk_private;    /* private cipher state */
};
#define IEEE80211_KEY_COMMON            /* common flags passed in by apps */\
        (IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV | IEEE80211_KEY_GROUP)

/*
 * NB: these values are ordered carefully; there are lots of
 * of implications in any reordering.  In particular beware
 * that 4 is not used to avoid conflicting with IEEE80211_F_PRIVACY.
 */
#define IEEE80211_CIPHER_WEP            0
#define IEEE80211_CIPHER_TKIP           1
#define IEEE80211_CIPHER_AES_OCB        2
#define IEEE80211_CIPHER_AES_CCM        3
#define IEEE80211_CIPHER_CKIP           5
#define IEEE80211_CIPHER_NONE           6       /* pseudo value */

#define IEEE80211_CIPHER_MAX            (IEEE80211_CIPHER_NONE+1)

#define IEEE80211_KEYIX_NONE    ((ieee80211_keyix) -1)
#define IEEE80211_KEY_UNDEFINED(k)      ((k).wk_cipher == &ieee80211_cipher_none)

#if defined(__KERNEL__) || defined(_KERNEL)

struct ieee80211com;
struct ieee80211_node;
struct mbuf;

/*
 * Crypto state kept in each ieee80211com.  Some of this
 * can/should be shared when virtual AP's are supported.
 *
 * XXX save reference to ieee80211com to properly encapsulate state.
 * XXX split out crypto capabilities from ic_caps
 */
struct ieee80211_crypto_state {
        struct ieee80211_key    cs_nw_keys[IEEE80211_WEP_NKID];
        ieee80211_keyix         cs_def_txkey;   /* default/group tx key index */
        u_int16_t               cs_max_keyix;   /* max h/w key index */

        int                     (*cs_key_alloc)(struct ieee80211com *,
                                        const struct ieee80211_key *,
                                        ieee80211_keyix *, ieee80211_keyix *);
        int                     (*cs_key_delete)(struct ieee80211com *, 
                                        const struct ieee80211_key *);
        int                     (*cs_key_set)(struct ieee80211com *,
                                        const struct ieee80211_key *,
                                        const u_int8_t mac[IEEE80211_ADDR_LEN]);
        void                    (*cs_key_update_begin)(struct ieee80211com *);
        void                    (*cs_key_update_end)(struct ieee80211com *);
};

void    ieee80211_crypto_attach(struct ieee80211com *);
void    ieee80211_crypto_detach(struct ieee80211com *);
int     ieee80211_crypto_newkey(struct ieee80211com *,
                int cipher, int flags, struct ieee80211_key *);
int     ieee80211_crypto_delkey(struct ieee80211com *,
                struct ieee80211_key *);
int     ieee80211_crypto_setkey(struct ieee80211com *,
                struct ieee80211_key *, const u_int8_t macaddr[IEEE80211_ADDR_LEN]);
void    ieee80211_crypto_delglobalkeys(struct ieee80211com *);

/*
 * Template for a supported cipher.  Ciphers register with the
 * crypto code and are typically loaded as separate modules
 * (the null cipher is always present).
 * XXX may need refcnts
 */
struct ieee80211_cipher {
        const char *ic_name;            /* printable name */
        u_int   ic_cipher;              /* IEEE80211_CIPHER_* */
        u_int   ic_header;              /* size of privacy header (bytes) */
        u_int   ic_trailer;             /* size of privacy trailer (bytes) */
        u_int   ic_miclen;              /* size of mic trailer (bytes) */
        void*   (*ic_attach)(struct ieee80211com *, struct ieee80211_key *);
        void    (*ic_detach)(struct ieee80211_key *);
        int     (*ic_setkey)(struct ieee80211_key *);
        int     (*ic_encap)(struct ieee80211_key *, struct mbuf *,
                        u_int8_t keyid);
        int     (*ic_decap)(struct ieee80211_key *, struct mbuf *, int);
        int     (*ic_enmic)(struct ieee80211_key *, struct mbuf *, int);
        int     (*ic_demic)(struct ieee80211_key *, struct mbuf *, int);
};
extern  const struct ieee80211_cipher ieee80211_cipher_none;
extern  const struct ieee80211_cipher ieee80211_cipher_wep;
extern  const struct ieee80211_cipher ieee80211_cipher_tkip;
extern  const struct ieee80211_cipher ieee80211_cipher_ccmp;

void    ieee80211_crypto_register(const struct ieee80211_cipher *);
void    ieee80211_crypto_unregister(const struct ieee80211_cipher *);
int     ieee80211_crypto_available(u_int cipher);

struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211com *,
                struct ieee80211_node *, struct mbuf *);
struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211com *,
                struct ieee80211_node *, struct mbuf **, int);

/*
 * Check and remove any MIC.
 */
static __inline int
ieee80211_crypto_demic(struct ieee80211com *ic,
    struct ieee80211_key *k, struct mbuf *m, int force)
{
        const struct ieee80211_cipher *cip = k->wk_cipher;
        return (cip->ic_miclen > 0 ? cip->ic_demic(k, m, force) : 1);
}

/*
 * Add any MIC.
 */
static __inline int
ieee80211_crypto_enmic(struct ieee80211com *ic,
        struct ieee80211_key *k, struct mbuf *m, int force)
{
        const struct ieee80211_cipher *cip = k->wk_cipher;
        return (cip->ic_miclen > 0 ? cip->ic_enmic(k, m, force) : 1);
}

/* 
 * Reset key state to an unused state.  The crypto
 * key allocation mechanism insures other state (e.g.
 * key data) is properly setup before a key is used.
 */
static __inline void
ieee80211_crypto_resetkey(struct ieee80211com *ic,
        struct ieee80211_key *k, ieee80211_keyix ix)
{
        k->wk_cipher = &ieee80211_cipher_none;
        k->wk_private = k->wk_cipher->ic_attach(ic, k);
        k->wk_keyix = k->wk_rxkeyix = ix;
        k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
}

/*
 * Crypt-related notification methods.
 */
void    ieee80211_notify_replay_failure(struct ieee80211com *,
                const struct ieee80211_frame *, const struct ieee80211_key *,
                u_int64_t rsc);
void    ieee80211_notify_michael_failure(struct ieee80211com *,
                const struct ieee80211_frame *, u_int keyix);
#endif /* defined(__KERNEL__) || defined(_KERNEL) */
#endif /* !_NET80211_IEEE80211_CRYPTO_H_ */