/*-
 * Copyright (c) 2001 Atsushi Onoe
 * Copyright (c) 2002-2008 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.
 *
 * 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.
 *
 * $FreeBSD$
 */
#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 */
        uint8_t         wk_key[IEEE80211_KEYBUF_SIZE];
};

struct ieee80211_rsnparms {
        uint8_t         rsn_mcastcipher;        /* mcast/group cipher */
        uint8_t         rsn_mcastkeylen;        /* mcast key length */
        uint8_t         rsn_ucastcipher;        /* selected unicast cipher */
        uint8_t         rsn_ucastkeylen;        /* unicast key length */
        uint8_t         rsn_keymgmt;            /* selected key mgmt algo */
        uint16_t        rsn_caps;               /* capabilities */
};

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 uint16_t ieee80211_keyix;       /* h/w key index */

struct ieee80211_key {
        uint8_t         wk_keylen;      /* key length in bytes */
        uint8_t         wk_pad;
        uint16_t        wk_flags;
#define IEEE80211_KEY_XMIT      0x0001  /* key used for xmit */
#define IEEE80211_KEY_RECV      0x0002  /* key used for recv */
#define IEEE80211_KEY_GROUP     0x0004  /* key used for WPA group operation */
#define IEEE80211_KEY_NOREPLAY  0x0008  /* ignore replay failures */
#define IEEE80211_KEY_SWENCRYPT 0x0010  /* host-based encrypt */
#define IEEE80211_KEY_SWDECRYPT 0x0020  /* host-based decrypt */
#define IEEE80211_KEY_SWENMIC   0x0040  /* host-based enmic */
#define IEEE80211_KEY_SWDEMIC   0x0080  /* host-based demic */
#define IEEE80211_KEY_DEVKEY    0x0100  /* device key request completed */
#define IEEE80211_KEY_CIPHER0   0x1000  /* cipher-specific action 0 */
#define IEEE80211_KEY_CIPHER1   0x2000  /* cipher-specific action 1 */
        ieee80211_keyix wk_keyix;       /* h/w key index */
        ieee80211_keyix wk_rxkeyix;     /* optional h/w rx key index */
        uint8_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 */
                                        /* key receive sequence counter */
        uint64_t        wk_keyrsc[IEEE80211_TID_SIZE];
        uint64_t        wk_keytsc;      /* key transmit sequence counter */
        const struct ieee80211_cipher *wk_cipher;
        void            *wk_private;    /* private cipher state */
        uint8_t         wk_macaddr[IEEE80211_ADDR_LEN];
};
#define IEEE80211_KEY_COMMON            /* common flags passed in by apps */\
        (IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV | IEEE80211_KEY_GROUP | \
         IEEE80211_KEY_NOREPLAY)
#define IEEE80211_KEY_DEVICE            /* flags owned by device driver */\
        (IEEE80211_KEY_DEVKEY|IEEE80211_KEY_CIPHER0|IEEE80211_KEY_CIPHER1)

#define IEEE80211_KEY_SWCRYPT \
        (IEEE80211_KEY_SWENCRYPT | IEEE80211_KEY_SWDECRYPT)
#define IEEE80211_KEY_SWMIC     (IEEE80211_KEY_SWENMIC | IEEE80211_KEY_SWDEMIC)

#define IEEE80211_KEY_BITS \
        "\20\1XMIT\2RECV\3GROUP\4SWENCRYPT\5SWDECRYPT\6SWENMIC\7SWDEMIC" \
        "\10DEVKEY\11CIPHER0\12CIPHER1"

#define IEEE80211_KEYIX_NONE    ((ieee80211_keyix) -1)

/*
 * NB: these values are ordered carefully; there are lots of
 * of implications in any reordering.  Beware that 4 is used
 * only to indicate h/w TKIP MIC support in driver capabilities;
 * there is no separate cipher support (it's rolled into the
 * TKIP cipher support).
 */
#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_TKIPMIC        4       /* TKIP MIC capability */
#define IEEE80211_CIPHER_CKIP           5
#define IEEE80211_CIPHER_NONE           6       /* pseudo value */

#define IEEE80211_CIPHER_MAX            (IEEE80211_CIPHER_NONE+1)

/* capability bits in ic_cryptocaps/iv_cryptocaps */
#define IEEE80211_CRYPTO_WEP            (1<<IEEE80211_CIPHER_WEP)
#define IEEE80211_CRYPTO_TKIP           (1<<IEEE80211_CIPHER_TKIP)
#define IEEE80211_CRYPTO_AES_OCB        (1<<IEEE80211_CIPHER_AES_OCB)
#define IEEE80211_CRYPTO_AES_CCM        (1<<IEEE80211_CIPHER_AES_CCM)
#define IEEE80211_CRYPTO_TKIPMIC        (1<<IEEE80211_CIPHER_TKIPMIC)
#define IEEE80211_CRYPTO_CKIP           (1<<IEEE80211_CIPHER_CKIP)

#define IEEE80211_CRYPTO_BITS \
        "\20\1WEP\2TKIP\3AES\4AES_CCM\5TKIPMIC\6CKIP"

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

struct ieee80211com;
struct ieee80211vap;
struct ieee80211_node;
struct mbuf;

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_80211_CRYPTO);
#endif

void    ieee80211_crypto_attach(struct ieee80211com *);
void    ieee80211_crypto_detach(struct ieee80211com *);
void    ieee80211_crypto_vattach(struct ieee80211vap *);
void    ieee80211_crypto_vdetach(struct ieee80211vap *);
int     ieee80211_crypto_newkey(struct ieee80211vap *,
                int cipher, int flags, struct ieee80211_key *);
int     ieee80211_crypto_delkey(struct ieee80211vap *,
                struct ieee80211_key *);
int     ieee80211_crypto_setkey(struct ieee80211vap *, struct ieee80211_key *);
void    ieee80211_crypto_delglobalkeys(struct ieee80211vap *);
void    ieee80211_crypto_reload_keys(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 ieee80211vap *, struct ieee80211_key *);
        void    (*ic_detach)(struct ieee80211_key *);
        int     (*ic_setkey)(struct ieee80211_key *);
        void    (*ic_setiv)(struct ieee80211_key *, uint8_t *);
        int     (*ic_encap)(struct ieee80211_key *, struct mbuf *);
        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;

#define IEEE80211_KEY_UNDEFINED(k) \
        ((k)->wk_cipher == &ieee80211_cipher_none)

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

uint8_t ieee80211_crypto_get_keyid(struct ieee80211vap *vap,
                struct ieee80211_key *k);
struct ieee80211_key *ieee80211_crypto_get_txkey(struct ieee80211_node *,
                struct mbuf *);
struct ieee80211_key *ieee80211_crypto_encap(struct ieee80211_node *,
                struct mbuf *);
struct ieee80211_key *ieee80211_crypto_decap(struct ieee80211_node *,
                struct mbuf *, int);

/*
 * Check and remove any MIC.
 */
static __inline int
ieee80211_crypto_demic(struct ieee80211vap *vap, 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 ieee80211vap *vap,
        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 ieee80211vap *vap,
        struct ieee80211_key *k, ieee80211_keyix ix)
{
        k->wk_cipher = &ieee80211_cipher_none;
        k->wk_private = k->wk_cipher->ic_attach(vap, 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 ieee80211vap *,
                const struct ieee80211_frame *, const struct ieee80211_key *,
                uint64_t rsc, int tid);
void    ieee80211_notify_michael_failure(struct ieee80211vap *,
                const struct ieee80211_frame *, u_int keyix);
#endif /* defined(__KERNEL__) || defined(_KERNEL) */
#endif /* _NET80211_IEEE80211_CRYPTO_H_ */