/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * 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.
 * 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.
 */

/*
 * IEEE 802.11i CCMP crypto support.
 */
#include <sys/byteorder.h>
#include <sys/crypto/common.h>
#include <sys/crypto/api.h>
#include <sys/crc32.h>
#include <sys/random.h>
#include <sys/strsun.h>
#include "net80211_impl.h"

struct ccmp_ctx {
        struct ieee80211com *cc_ic;     /* for diagnostics */
};

#define AES_BLOCK_LEN   16
#define AES_NONCE_LEN   13

static void *ccmp_attach(struct ieee80211com *, struct ieee80211_key *);
static void ccmp_detach(struct ieee80211_key *);
static int ccmp_setkey(struct ieee80211_key *);
static int ccmp_encap(struct ieee80211_key *k, mblk_t *, uint8_t);
static int ccmp_decap(struct ieee80211_key *, mblk_t *, int);
static int ccmp_enmic(struct ieee80211_key *, mblk_t *, int);
static int ccmp_demic(struct ieee80211_key *, mblk_t *, int);

static int ccmp_encrypt(struct ieee80211_key *, mblk_t *, int);
static int ccmp_decrypt(struct ieee80211_key *, uint64_t pn, mblk_t *, int);

const struct ieee80211_cipher ccmp = {
        "AES-CCM",
        IEEE80211_CIPHER_AES_CCM,
        IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN +
            IEEE80211_WEP_EXTIVLEN,
        IEEE80211_WEP_MICLEN,
        0,
        ccmp_attach,
        ccmp_detach,
        ccmp_setkey,
        ccmp_encap,
        ccmp_decap,
        ccmp_enmic,
        ccmp_demic,
};

/* ARGSUSED */
static void *
ccmp_attach(struct ieee80211com *ic, struct ieee80211_key *k)
{
        struct ccmp_ctx *ctx;

        ctx = kmem_zalloc(sizeof (struct ccmp_ctx), KM_SLEEP);
        if (ctx == NULL)
                return (NULL);

        ctx->cc_ic = ic;
        return (ctx);
}

static void
ccmp_detach(struct ieee80211_key *k)
{
        struct ccmp_ctx *ctx = k->wk_private;

        if (ctx != NULL)
                kmem_free(ctx, sizeof (struct ccmp_ctx));
}

static int
ccmp_setkey(struct ieee80211_key *k)
{
        if (k->wk_keylen != (128/NBBY))
                return (0);

        return (1);
}

/*
 * Add privacy headers appropriate for the specified key.
 */
static int
ccmp_encap(struct ieee80211_key *k, mblk_t *mp, uint8_t keyid)
{
        struct ccmp_ctx *ctx = k->wk_private;
        uint8_t *ivp;
        int hdrlen;

        hdrlen = ieee80211_hdrspace(ctx->cc_ic, mp->b_rptr);
        /*
         * Copy down 802.11 header and add the IV, KeyID, and ExtIV.
         */
        ivp = mp->b_rptr;
        ivp += hdrlen;

        k->wk_keytsc++;                         /* wrap at 48 bits */
        ivp[0] = k->wk_keytsc >> 0;             /* PN0 */
        ivp[1] = k->wk_keytsc >> 8;             /* PN1 */
        ivp[2] = 0;                             /* Reserved */
        ivp[3] = keyid | IEEE80211_WEP_EXTIV;   /* KeyID | ExtID */
        ivp[4] = k->wk_keytsc >> 16;            /* PN2 */
        ivp[5] = k->wk_keytsc >> 24;            /* PN3 */
        ivp[6] = k->wk_keytsc >> 32;            /* PN4 */
        ivp[7] = k->wk_keytsc >> 40;            /* PN5 */

        /*
         * Finally, do software encrypt if neeed.
         */
        if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) &&
            !ccmp_encrypt(k, mp, hdrlen))
                return (0);

        return (1);
}

/*
 * Validate and strip privacy headers (and trailer) for a
 * received frame. The specified key should be correct but
 * is also verified.
 */
static int
ccmp_decap(struct ieee80211_key *k, mblk_t *mp, int hdrlen)
{
        uint8_t *ivp;
        uint64_t pn;

        /*
         * Header should have extended IV and sequence number;
         * verify the former and validate the latter.
         */
        ivp = mp->b_rptr + hdrlen;
        if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) {
                /*
                 * No extended IV; discard frame.
                 */
                return (0);
        }

        pn = ieee80211_read_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]);
        if (pn <= k->wk_keyrsc) {
                /*
                 * Replay violation.
                 */
                return (0);
        }

        /*
         * Check if the device handled the decrypt in hardware.
         * If so we just strip the header; otherwise we need to
         * handle the decrypt in software.  Note that for the
         * latter we leave the header in place for use in the
         * decryption work.
         */
        if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) &&
            !ccmp_decrypt(k, pn, mp, hdrlen))
                return (0);

        /*
         * Copy up 802.11 header and strip crypto bits.
         */
        (void) memmove(mp->b_rptr + ccmp.ic_header, mp->b_rptr, hdrlen);
        mp->b_rptr += ccmp.ic_header;
        mp->b_wptr -= ccmp.ic_trailer;

        /*
         * Ok to update rsc now.
         */
        k->wk_keyrsc = pn;

        return (1);
}

/*
 * Add MIC to the frame as needed.
 */
/* ARGSUSED */
static int
ccmp_enmic(struct ieee80211_key *k, mblk_t *mp, int force)
{
        return (1);
}

/*
 * Verify and strip MIC from the frame.
 */
/* ARGSUSED */
static int
ccmp_demic(struct ieee80211_key *k, mblk_t *mp, int force)
{
        return (1);
}

static int
aes_ccm_encrypt(CK_AES_CCM_PARAMS *cmparam, const uint8_t *key, int keylen,
    const uint8_t *plaintext, int plain_len,
    uint8_t *ciphertext, int cipher_len)
{
        crypto_mechanism_t mech;
        crypto_key_t crkey;
        crypto_data_t d1, d2;

        int rv;

        ieee80211_dbg(IEEE80211_MSG_CRYPTO,
            "aes_ccm_encrypt(len=%d, keylen=%d)", plain_len, keylen);

        bzero(&crkey, sizeof (crkey));

        crkey.ck_format = CRYPTO_KEY_RAW;
        crkey.ck_data   = (char *)key;
        /* keys are measured in bits, not bytes, so multiply by 8 */
        crkey.ck_length = keylen * 8;

        mech.cm_type      = crypto_mech2id(SUN_CKM_AES_CCM);
        mech.cm_param     = (caddr_t)cmparam;
        mech.cm_param_len = sizeof (CK_AES_CCM_PARAMS);

#if defined(_LP64)
        ieee80211_dbg(IEEE80211_MSG_CRYPTO, "cm_type=%lx", mech.cm_type);
#else
        ieee80211_dbg(IEEE80211_MSG_CRYPTO, "cm_type=%llx", mech.cm_type);
#endif

        bzero(&d1, sizeof (d1));
        bzero(&d2, sizeof (d2));

        d1.cd_format = CRYPTO_DATA_RAW;
        d1.cd_offset = 0;
        d1.cd_length = plain_len;
        d1.cd_raw.iov_base = (char *)plaintext;
        d1.cd_raw.iov_len  = plain_len;

        d2.cd_format = CRYPTO_DATA_RAW;
        d2.cd_offset = 0;
        d2.cd_length = cipher_len;
        d2.cd_raw.iov_base = (char *)ciphertext;
        d2.cd_raw.iov_len  = cipher_len;


        rv = crypto_encrypt(&mech, &d1, &crkey, NULL, &d2, NULL);
        if (rv != CRYPTO_SUCCESS)
                ieee80211_err("aes_ccm_encrypt failed (%x)", rv);
        return (rv);
}

static int
aes_ccm_decrypt(CK_AES_CCM_PARAMS *cmparam, const uint8_t *key, int keylen,
    const uint8_t *ciphertext, int cipher_len,
    uint8_t *plaintext, int plain_len)
{
        crypto_mechanism_t mech;
        crypto_key_t crkey;
        crypto_data_t d1, d2;

        int rv;

        ieee80211_dbg(IEEE80211_MSG_CRYPTO,
            "aes_ccm_decrypt(len=%d, keylen=%d)", cipher_len, keylen);

        bzero(&crkey, sizeof (crkey));

        crkey.ck_format = CRYPTO_KEY_RAW;
        crkey.ck_data   = (char *)key;
        /* keys are measured in bits, not bytes, so multiply by 8 */
        crkey.ck_length = keylen * 8;

        mech.cm_type      = crypto_mech2id(SUN_CKM_AES_CCM);
        mech.cm_param     = (caddr_t)cmparam;
        mech.cm_param_len = sizeof (CK_AES_CCM_PARAMS);

#if defined(_LP64)
        ieee80211_dbg(IEEE80211_MSG_CRYPTO, "cm_type=%lx", mech.cm_type);
#else
        ieee80211_dbg(IEEE80211_MSG_CRYPTO, "cm_type=%llx", mech.cm_type);
#endif

        bzero(&d1, sizeof (d1));
        bzero(&d2, sizeof (d2));

        d1.cd_format = CRYPTO_DATA_RAW;
        d1.cd_offset = 0;
        d1.cd_length = cipher_len;
        d1.cd_raw.iov_base = (char *)ciphertext;
        d1.cd_raw.iov_len  = cipher_len;

        d2.cd_format = CRYPTO_DATA_RAW;
        d2.cd_offset = 0;
        d2.cd_length = plain_len;
        d2.cd_raw.iov_base = (char *)plaintext;
        d2.cd_raw.iov_len  = plain_len;


        rv = crypto_decrypt(&mech, &d1, &crkey, NULL, &d2, NULL);
        if (rv != CRYPTO_SUCCESS)
                ieee80211_err("aes_ccm_decrypt failed (%x)", rv);
        return (rv);
}

/*
 * For the avoidance of doubt, except that if any license choice other
 * than GPL or LGPL is available it will apply instead, Sun elects to
 * use only the General Public License version 2 (GPLv2) at this time
 * for any software where a choice of GPL license versions is made
 * available with the language indicating that GPLv2 or any later
 * version may be used, or where a choice of which version of the GPL
 * is applied is otherwise unspecified.
 */

/*
 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver
 *
 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. See README and COPYING for
 * more details.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 */

static void
ccmp_init(struct ieee80211_frame *wh, uint64_t pn, size_t dlen,
    uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN])
{
        /*
         * CCM Initial Block:
         * Flag (Include authentication header, M=3 (8-octet MIC),
         * L=1 (2-octet Dlen))
         * Nonce: 0x00 | A2 | PN
         * Dlen
         */
        b0[0] = 0x59;
        /* b0[1] set below */
        IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2);
        b0[8] = pn >> 40;
        b0[9] = pn >> 32;
        b0[10] = pn >> 24;
        b0[11] = pn >> 16;
        b0[12] = pn >> 8;
        b0[13] = (uint8_t)(pn >> 0);
        b0[14] = (dlen >> 8) & 0xff;
        b0[15] = dlen & 0xff;

        /*
         * AAD:
         * FC with bits 4..6 and 11..13 masked to zero; 14 is always one
         * A1 | A2 | A3
         * SC with bits 4..15 (seq#) masked to zero
         * A4 (if present)
         * QC (if present)
         */
        aad[0] = 0;     /* AAD length >> 8 */
        /* aad[1] set below */
        aad[2] = wh->i_fc[0] & 0x8f;    /* magic #s */
        aad[3] = wh->i_fc[1] & 0xc7;    /* magic #s */
        /* we know 3 addresses are contiguous */
        (void) memcpy(aad + 4, wh->i_addr1, 3 * IEEE80211_ADDR_LEN);
        aad[22] = wh->i_seq[0] & IEEE80211_SEQ_FRAG_MASK;
        aad[23] = 0; /* all bits masked */
        /*
         * Construct variable-length portion of AAD based
         * on whether this is a 4-address frame/QOS frame.
         * We always zero-pad to 32 bytes before running it
         * through the cipher.
         *
         * We also fill in the priority bits of the CCM
         * initial block as we know whether or not we have
         * a QOS frame.
         */
        if (IEEE80211_QOS_HAS_SEQ(wh)) {
                struct ieee80211_qosframe *qwh =
                    (struct ieee80211_qosframe *)wh;
                aad[24] = qwh->i_qos[0] & 0x0f; /* just priority bits */
                aad[25] = 0;
                b0[1] = aad[24];
                aad[1] = 22 + 2;
        } else {
                *(uint16_t *)&aad[24] = 0;
                b0[1] = 0;
                aad[1] = 22;
        }
        *(uint16_t *)&aad[26] = 0;
        *(uint32_t *)&aad[28] = 0;
}

static int
ccmp_encrypt(struct ieee80211_key *key, mblk_t *mp, int hdrlen)
{
        struct ieee80211_frame *wh;
        int rv, data_len;
        uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN];
        uint8_t *pos;
        CK_AES_CCM_PARAMS cmparam;

        wh = (struct ieee80211_frame *)mp->b_rptr;
        data_len = MBLKL(mp) - (hdrlen + ccmp.ic_header);
        pos = mp->b_rptr + hdrlen + ccmp.ic_header;

        ccmp_init(wh, key->wk_keytsc, data_len, b0, aad);

        cmparam.ulMACSize = IEEE80211_WEP_MICLEN;
        cmparam.ulNonceSize = AES_NONCE_LEN; /* N size */
        cmparam.ulAuthDataSize = aad[1]; /* A size */
        cmparam.ulDataSize = data_len;  /* data length; */
        cmparam.nonce = &b0[1]; /* N */
        cmparam.authData = &aad[2]; /* A */

        rv = aes_ccm_encrypt(&cmparam,
            key->wk_key, key->wk_keylen,
            pos, data_len, pos, data_len + IEEE80211_WEP_MICLEN);

        mp->b_wptr += ccmp.ic_trailer;

        return ((rv == CRYPTO_SUCCESS)? 1 : 0);
}

static int
ccmp_decrypt(struct ieee80211_key *key, uint64_t pn, mblk_t *mp, int hdrlen)
{
        struct ieee80211_frame *wh;
        int rv, data_len;
        uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN];
        uint8_t *pos;
        CK_AES_CCM_PARAMS cmparam;

        wh = (struct ieee80211_frame *)mp->b_rptr;
        data_len = MBLKL(mp) - (hdrlen + ccmp.ic_header);
        pos = mp->b_rptr + hdrlen + ccmp.ic_header;

        ccmp_init(wh, pn, data_len, b0, aad);

        cmparam.ulMACSize = IEEE80211_WEP_MICLEN; /* MIC = 8 */
        cmparam.ulNonceSize = AES_NONCE_LEN; /* N size */
        cmparam.ulAuthDataSize = aad[1]; /* A size */
        cmparam.ulDataSize = data_len;
        cmparam.nonce = &b0[1]; /* N */
        cmparam.authData = &aad[2]; /* A */

        rv = aes_ccm_decrypt(&cmparam,
            key->wk_key, key->wk_keylen, pos, data_len, pos, data_len);

        return ((rv == CRYPTO_SUCCESS)? 1 : 0);
}