io/net80211/net80211_crypto_ccmp.c

	net80211_crypto_ccmp.c revision ff3124eff995e6cd8ebd8c6543648e0670920034
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * 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.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * 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)
{
    uint8_t *ivp;
    int hdrlen;

    hdrlen = ieee80211_hdrspace(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)
{
    struct ieee80211_frame tmp;
    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.
     */
    bcopy(mp->b_rptr, &tmp, hdrlen);
    bcopy(&tmp, mp->b_rptr + ccmp.ic_header, 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(__amd64) || defined(__sparc)
    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(__amd64) || defined(__sparc)
    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.
     */
    *(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;
    uint8_t buf[IEEE80211_MAX_LEN];

    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, buf, data_len + IEEE80211_WEP_MICLEN);

    bcopy(buf, 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;
    uint8_t buf[IEEE80211_MAX_LEN];

    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, buf, data_len);
    bcopy(buf, pos, data_len);

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