/*
 * Host AP crypt: host-based TKIP 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.
 */

//#include <linux/config.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>
#include <asm/string.h>

#include "ieee80211.h"


#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
#include "rtl_crypto.h"
#else
#include <linux/crypto.h>
#endif
//#include <asm/scatterlist.h>
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
    #include <asm/scatterlist.h>
#else
        #include <linux/scatterlist.h>
#endif

#include <linux/crc32.h>

MODULE_AUTHOR("Jouni Malinen");
MODULE_DESCRIPTION("Host AP crypt: TKIP");
MODULE_LICENSE("GPL");

#ifndef OPENSUSE_SLED
#define OPENSUSE_SLED 0
#endif

struct ieee80211_tkip_data {
#define TKIP_KEY_LEN 32
        u8 key[TKIP_KEY_LEN];
        int key_set;

        u32 tx_iv32;
        u16 tx_iv16;
        u16 tx_ttak[5];
        int tx_phase1_done;

        u32 rx_iv32;
        u16 rx_iv16;
        u16 rx_ttak[5];
        int rx_phase1_done;
        u32 rx_iv32_new;
        u16 rx_iv16_new;

        u32 dot11RSNAStatsTKIPReplays;
        u32 dot11RSNAStatsTKIPICVErrors;
        u32 dot11RSNAStatsTKIPLocalMICFailures;

        int key_idx;
#if((LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21)) || (OPENSUSE_SLED))
        struct crypto_blkcipher *rx_tfm_arc4;
        struct crypto_hash *rx_tfm_michael;
        struct crypto_blkcipher *tx_tfm_arc4;
        struct crypto_hash *tx_tfm_michael;
#else
        struct crypto_tfm *tx_tfm_arc4;
        struct crypto_tfm *tx_tfm_michael;
        struct crypto_tfm *rx_tfm_arc4;
        struct crypto_tfm *rx_tfm_michael;
#endif
        /* scratch buffers for virt_to_page() (crypto API) */
        u8 rx_hdr[16], tx_hdr[16];
};

static void * ieee80211_tkip_init(int key_idx)
{
        struct ieee80211_tkip_data *priv;

        priv = kmalloc(sizeof(*priv), GFP_ATOMIC);
        if (priv == NULL)
                goto fail;
        memset(priv, 0, sizeof(*priv));
        priv->key_idx = key_idx;
#if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
        priv->tx_tfm_arc4 = crypto_alloc_tfm("arc4", 0);
        if (priv->tx_tfm_arc4 == NULL) {
                printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
                                "crypto API arc4\n");
                goto fail;
        }

        priv->tx_tfm_michael = crypto_alloc_tfm("michael_mic", 0);
        if (priv->tx_tfm_michael == NULL) {
                printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
                                "crypto API michael_mic\n");
                goto fail;
        }

        priv->rx_tfm_arc4 = crypto_alloc_tfm("arc4", 0);
        if (priv->rx_tfm_arc4 == NULL) {
                printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
                                "crypto API arc4\n");
                goto fail;
        }

        priv->rx_tfm_michael = crypto_alloc_tfm("michael_mic", 0);
        if (priv->rx_tfm_michael == NULL) {
                printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
                                "crypto API michael_mic\n");
                goto fail;
        }
#else
        priv->tx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0,
                        CRYPTO_ALG_ASYNC);
        if (IS_ERR(priv->tx_tfm_arc4)) {
                printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
                                "crypto API arc4\n");
                priv->tx_tfm_arc4 = NULL;
                goto fail;
        }

        priv->tx_tfm_michael = crypto_alloc_hash("michael_mic", 0,
                        CRYPTO_ALG_ASYNC);
        if (IS_ERR(priv->tx_tfm_michael)) {
                printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
                                "crypto API michael_mic\n");
                priv->tx_tfm_michael = NULL;
                goto fail;
        }

        priv->rx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0,
                        CRYPTO_ALG_ASYNC);
        if (IS_ERR(priv->rx_tfm_arc4)) {
                printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
                                "crypto API arc4\n");
                priv->rx_tfm_arc4 = NULL;
                goto fail;
        }

        priv->rx_tfm_michael = crypto_alloc_hash("michael_mic", 0,
                        CRYPTO_ALG_ASYNC);
        if (IS_ERR(priv->rx_tfm_michael)) {
                printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
                                "crypto API michael_mic\n");
                priv->rx_tfm_michael = NULL;
                goto fail;
        }
#endif
        return priv;

fail:
        if (priv) {
#if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
                if (priv->tx_tfm_michael)
                        crypto_free_tfm(priv->tx_tfm_michael);
                if (priv->tx_tfm_arc4)
                        crypto_free_tfm(priv->tx_tfm_arc4);
                if (priv->rx_tfm_michael)
                        crypto_free_tfm(priv->rx_tfm_michael);
                if (priv->rx_tfm_arc4)
                        crypto_free_tfm(priv->rx_tfm_arc4);

#else
                if (priv->tx_tfm_michael)
                        crypto_free_hash(priv->tx_tfm_michael);
                if (priv->tx_tfm_arc4)
                        crypto_free_blkcipher(priv->tx_tfm_arc4);
                if (priv->rx_tfm_michael)
                        crypto_free_hash(priv->rx_tfm_michael);
                if (priv->rx_tfm_arc4)
                        crypto_free_blkcipher(priv->rx_tfm_arc4);
#endif
                kfree(priv);
        }

        return NULL;
}


static void ieee80211_tkip_deinit(void *priv)
{
        struct ieee80211_tkip_data *_priv = priv;
#if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
        if (_priv->tx_tfm_michael)
                crypto_free_tfm(_priv->tx_tfm_michael);
        if (_priv->tx_tfm_arc4)
                crypto_free_tfm(_priv->tx_tfm_arc4);
        if (_priv->rx_tfm_michael)
                crypto_free_tfm(_priv->rx_tfm_michael);
        if (_priv->rx_tfm_arc4)
                crypto_free_tfm(_priv->rx_tfm_arc4);
#else
        if (_priv) {
                if (_priv->tx_tfm_michael)
                        crypto_free_hash(_priv->tx_tfm_michael);
                if (_priv->tx_tfm_arc4)
                        crypto_free_blkcipher(_priv->tx_tfm_arc4);
                if (_priv->rx_tfm_michael)
                        crypto_free_hash(_priv->rx_tfm_michael);
                if (_priv->rx_tfm_arc4)
                        crypto_free_blkcipher(_priv->rx_tfm_arc4);
        }
#endif
        kfree(priv);
}


static inline u16 RotR1(u16 val)
{
        return (val >> 1) | (val << 15);
}


static inline u8 Lo8(u16 val)
{
        return val & 0xff;
}


static inline u8 Hi8(u16 val)
{
        return val >> 8;
}


static inline u16 Lo16(u32 val)
{
        return val & 0xffff;
}


static inline u16 Hi16(u32 val)
{
        return val >> 16;
}


static inline u16 Mk16(u8 hi, u8 lo)
{
        return lo | (((u16) hi) << 8);
}


static inline u16 Mk16_le(u16 *v)
{
        return le16_to_cpu(*v);
}


static const u16 Sbox[256] =
{
        0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
        0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
        0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
        0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
        0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
        0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
        0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
        0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
        0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
        0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
        0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
        0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
        0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
        0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
        0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
        0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
        0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
        0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
        0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
        0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
        0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
        0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
        0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
        0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
        0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
        0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
        0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
        0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
        0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
        0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
        0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
        0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
};


static inline u16 _S_(u16 v)
{
        u16 t = Sbox[Hi8(v)];
        return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8));
}


#define PHASE1_LOOP_COUNT 8


static void tkip_mixing_phase1(u16 *TTAK, const u8 *TK, const u8 *TA, u32 IV32)
{
        int i, j;

        /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */
        TTAK[0] = Lo16(IV32);
        TTAK[1] = Hi16(IV32);
        TTAK[2] = Mk16(TA[1], TA[0]);
        TTAK[3] = Mk16(TA[3], TA[2]);
        TTAK[4] = Mk16(TA[5], TA[4]);

        for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
                j = 2 * (i & 1);
                TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]));
                TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]));
                TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]));
                TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]));
                TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i;
        }
}


static void tkip_mixing_phase2(u8 *WEPSeed, const u8 *TK, const u16 *TTAK,
                               u16 IV16)
{
        /* Make temporary area overlap WEP seed so that the final copy can be
         * avoided on little endian hosts. */
        u16 *PPK = (u16 *) &WEPSeed[4];

        /* Step 1 - make copy of TTAK and bring in TSC */
        PPK[0] = TTAK[0];
        PPK[1] = TTAK[1];
        PPK[2] = TTAK[2];
        PPK[3] = TTAK[3];
        PPK[4] = TTAK[4];
        PPK[5] = TTAK[4] + IV16;

        /* Step 2 - 96-bit bijective mixing using S-box */
        PPK[0] += _S_(PPK[5] ^ Mk16_le((u16 *) &TK[0]));
        PPK[1] += _S_(PPK[0] ^ Mk16_le((u16 *) &TK[2]));
        PPK[2] += _S_(PPK[1] ^ Mk16_le((u16 *) &TK[4]));
        PPK[3] += _S_(PPK[2] ^ Mk16_le((u16 *) &TK[6]));
        PPK[4] += _S_(PPK[3] ^ Mk16_le((u16 *) &TK[8]));
        PPK[5] += _S_(PPK[4] ^ Mk16_le((u16 *) &TK[10]));

        PPK[0] += RotR1(PPK[5] ^ Mk16_le((u16 *) &TK[12]));
        PPK[1] += RotR1(PPK[0] ^ Mk16_le((u16 *) &TK[14]));
        PPK[2] += RotR1(PPK[1]);
        PPK[3] += RotR1(PPK[2]);
        PPK[4] += RotR1(PPK[3]);
        PPK[5] += RotR1(PPK[4]);

        /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
         * WEPSeed[0..2] is transmitted as WEP IV */
        WEPSeed[0] = Hi8(IV16);
        WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F;
        WEPSeed[2] = Lo8(IV16);
        WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((u16 *) &TK[0])) >> 1);

#ifdef __BIG_ENDIAN
        {
                int i;
                for (i = 0; i < 6; i++)
                        PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8);
        }
#endif
}


static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
        struct ieee80211_tkip_data *tkey = priv;
                int len;
        u8 *pos;
        struct ieee80211_hdr_4addr *hdr;
        cb_desc *tcb_desc = (cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);

        #if((LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21)) || (OPENSUSE_SLED))
        struct blkcipher_desc desc = {.tfm = tkey->tx_tfm_arc4};
        int ret = 0;
        #endif
        u8 rc4key[16],  *icv;
        u32 crc;
        struct scatterlist sg;

        if (skb_headroom(skb) < 8 || skb_tailroom(skb) < 4 ||
            skb->len < hdr_len)
                return -1;

        hdr = (struct ieee80211_hdr_4addr *) skb->data;

#if 0
printk("@@ tkey\n");
printk("%x|", ((u32*)tkey->key)[0]);
printk("%x|", ((u32*)tkey->key)[1]);
printk("%x|", ((u32*)tkey->key)[2]);
printk("%x|", ((u32*)tkey->key)[3]);
printk("%x|", ((u32*)tkey->key)[4]);
printk("%x|", ((u32*)tkey->key)[5]);
printk("%x|", ((u32*)tkey->key)[6]);
printk("%x\n", ((u32*)tkey->key)[7]);
#endif

        if (!tcb_desc->bHwSec)
        {
                if (!tkey->tx_phase1_done) {
                        tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2,
                                        tkey->tx_iv32);
                        tkey->tx_phase1_done = 1;
                }
                tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16);
        }
        else
        tkey->tx_phase1_done = 1;


        len = skb->len - hdr_len;
        pos = skb_push(skb, 8);
        memmove(pos, pos + 8, hdr_len);
        pos += hdr_len;

        if (tcb_desc->bHwSec)
        {
                *pos++ = Hi8(tkey->tx_iv16);
                *pos++ = (Hi8(tkey->tx_iv16) | 0x20) & 0x7F;
                *pos++ = Lo8(tkey->tx_iv16);
        }
        else
        {
                *pos++ = rc4key[0];
                *pos++ = rc4key[1];
                *pos++ = rc4key[2];
        }

        *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */;
        *pos++ = tkey->tx_iv32 & 0xff;
        *pos++ = (tkey->tx_iv32 >> 8) & 0xff;
        *pos++ = (tkey->tx_iv32 >> 16) & 0xff;
        *pos++ = (tkey->tx_iv32 >> 24) & 0xff;

        if (!tcb_desc->bHwSec)
        {
                icv = skb_put(skb, 4);
#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
                crc = ~crc32_le(~0, pos, len);
#else
                crc = ~ether_crc_le(len, pos);
#endif
                icv[0] = crc;
                icv[1] = crc >> 8;
                icv[2] = crc >> 16;
                icv[3] = crc >> 24;
#if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
                crypto_cipher_setkey(tkey->tx_tfm_arc4, rc4key, 16);
                sg.page = virt_to_page(pos);
                sg.offset = offset_in_page(pos);
                sg.length = len + 4;
                crypto_cipher_encrypt(tkey->tx_tfm_arc4, &sg, &sg, len + 4);
#else
                crypto_blkcipher_setkey(tkey->tx_tfm_arc4, rc4key, 16);
#if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24))
                sg.page = virt_to_page(pos);
                sg.offset = offset_in_page(pos);
                sg.length = len + 4;
#else
                sg_init_one(&sg, pos, len+4);
#endif
                ret= crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4);
#endif

        }

        tkey->tx_iv16++;
        if (tkey->tx_iv16 == 0) {
                tkey->tx_phase1_done = 0;
                tkey->tx_iv32++;
        }

        if (!tcb_desc->bHwSec)
#if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
                return 0;
        #else
                return ret;
        #endif
        else
                return 0;


}

static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
        struct ieee80211_tkip_data *tkey = priv;
        u8 keyidx, *pos;
        u32 iv32;
        u16 iv16;
        struct ieee80211_hdr_4addr *hdr;
        cb_desc *tcb_desc = (cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
        #if((LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21)) || (OPENSUSE_SLED))
        struct blkcipher_desc desc = {.tfm = tkey->rx_tfm_arc4};
        #endif
        u8 rc4key[16];
        u8 icv[4];
        u32 crc;
        struct scatterlist sg;
        int plen;
        if (skb->len < hdr_len + 8 + 4)
                return -1;

        hdr = (struct ieee80211_hdr_4addr *) skb->data;
        pos = skb->data + hdr_len;
        keyidx = pos[3];
        if (!(keyidx & (1 << 5))) {
                if (net_ratelimit()) {
                        printk(KERN_DEBUG "TKIP: received packet without ExtIV"
                               " flag from " MAC_FMT "\n", MAC_ARG(hdr->addr2));
                }
                return -2;
        }
        keyidx >>= 6;
        if (tkey->key_idx != keyidx) {
                printk(KERN_DEBUG "TKIP: RX tkey->key_idx=%d frame "
                       "keyidx=%d priv=%p\n", tkey->key_idx, keyidx, priv);
                return -6;
        }
        if (!tkey->key_set) {
                if (net_ratelimit()) {
                        printk(KERN_DEBUG "TKIP: received packet from " MAC_FMT
                               " with keyid=%d that does not have a configured"
                               " key\n", MAC_ARG(hdr->addr2), keyidx);
                }
                return -3;
        }
        iv16 = (pos[0] << 8) | pos[2];
        iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24);
        pos += 8;

        if (!tcb_desc->bHwSec)
        {
                if (iv32 < tkey->rx_iv32 ||
                (iv32 == tkey->rx_iv32 && iv16 <= tkey->rx_iv16)) {
                        if (net_ratelimit()) {
                                printk(KERN_DEBUG "TKIP: replay detected: STA=" MAC_FMT
                                " previous TSC %08x%04x received TSC "
                                "%08x%04x\n", MAC_ARG(hdr->addr2),
                                tkey->rx_iv32, tkey->rx_iv16, iv32, iv16);
                        }
                        tkey->dot11RSNAStatsTKIPReplays++;
                        return -4;
                }

                if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) {
                        tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32);
                        tkey->rx_phase1_done = 1;
                }
                tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16);

                plen = skb->len - hdr_len - 12;

#if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
                crypto_cipher_setkey(tkey->rx_tfm_arc4, rc4key, 16);
                sg.page = virt_to_page(pos);
                sg.offset = offset_in_page(pos);
                sg.length = plen + 4;
                crypto_cipher_decrypt(tkey->rx_tfm_arc4, &sg, &sg, plen + 4);
#else
                crypto_blkcipher_setkey(tkey->rx_tfm_arc4, rc4key, 16);
#if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24))
                sg.page = virt_to_page(pos);
                sg.offset = offset_in_page(pos);
                sg.length = plen + 4;
#else
                sg_init_one(&sg, pos, plen+4);
#endif
                if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4)) {
                        if (net_ratelimit()) {
                                printk(KERN_DEBUG ": TKIP: failed to decrypt "
                                                "received packet from " MAC_FMT "\n",
                                                MAC_ARG(hdr->addr2));
                        }
                        return -7;
                }
#endif

        #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
                crc = ~crc32_le(~0, pos, plen);
        #else
                crc = ~ether_crc_le(plen, pos);
        #endif
                icv[0] = crc;
                icv[1] = crc >> 8;
                icv[2] = crc >> 16;
                icv[3] = crc >> 24;

                if (memcmp(icv, pos + plen, 4) != 0) {
                        if (iv32 != tkey->rx_iv32) {
                                /* Previously cached Phase1 result was already lost, so
                                * it needs to be recalculated for the next packet. */
                                tkey->rx_phase1_done = 0;
                        }
                        if (net_ratelimit()) {
                                printk(KERN_DEBUG "TKIP: ICV error detected: STA="
                                MAC_FMT "\n", MAC_ARG(hdr->addr2));
                        }
                        tkey->dot11RSNAStatsTKIPICVErrors++;
                        return -5;
                }

        }

        /* Update real counters only after Michael MIC verification has
         * completed */
        tkey->rx_iv32_new = iv32;
        tkey->rx_iv16_new = iv16;

        /* Remove IV and ICV */
        memmove(skb->data + 8, skb->data, hdr_len);
        skb_pull(skb, 8);
        skb_trim(skb, skb->len - 4);

//john's test
#ifdef JOHN_DUMP
if( ((u16*)skb->data)[0] & 0x4000){
        printk("@@ rx decrypted skb->data");
        int i;
        for(i=0;i<skb->len;i++){
                if( (i%24)==0 ) printk("\n");
                printk("%2x ", ((u8*)skb->data)[i]);
        }
        printk("\n");
}
#endif /*JOHN_DUMP*/
        return keyidx;
}


#if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
static int michael_mic(struct crypto_tfm * tfm_michael, u8 *key, u8 *hdr,
                       u8 *data, size_t data_len, u8 *mic)
{
        struct scatterlist sg[2];
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
        struct hash_desc desc;
        int ret = 0;
#endif

        if (tfm_michael == NULL){
                printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n");
                return -1;
        }
        sg[0].page = virt_to_page(hdr);
        sg[0].offset = offset_in_page(hdr);
        sg[0].length = 16;

        sg[1].page = virt_to_page(data);
        sg[1].offset = offset_in_page(data);
        sg[1].length = data_len;


#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
        crypto_digest_init(tfm_michael);
        crypto_digest_setkey(tfm_michael, key, 8);
        crypto_digest_update(tfm_michael, sg, 2);
        crypto_digest_final(tfm_michael, mic);
        return 0;
#else
if (crypto_hash_setkey(tkey->tfm_michael, key, 8))
                return -1;

//      return 0;
              desc.tfm = tkey->tfm_michael;
              desc.flags = 0;
              ret = crypto_hash_digest(&desc, sg, data_len + 16, mic);
              return ret;
#endif
}
#else
static int michael_mic(struct crypto_hash *tfm_michael, u8 * key, u8 * hdr,
                       u8 * data, size_t data_len, u8 * mic)
{
        struct hash_desc desc;
        struct scatterlist sg[2];

        if (tfm_michael == NULL) {
                printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n");
                return -1;
        }
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
        sg[0].page = virt_to_page(hdr);
        sg[0].offset = offset_in_page(hdr);
        sg[0].length = 16;

        sg[1].page = virt_to_page(data);
        sg[1].offset = offset_in_page(data);
        sg[1].length = data_len;
#else
        sg_init_table(sg, 2);
        sg_set_buf(&sg[0], hdr, 16);
        sg_set_buf(&sg[1], data, data_len);
#endif

        if (crypto_hash_setkey(tfm_michael, key, 8))
                return -1;

        desc.tfm = tfm_michael;
        desc.flags = 0;
        return crypto_hash_digest(&desc, sg, data_len + 16, mic);
}
#endif



static void michael_mic_hdr(struct sk_buff *skb, u8 *hdr)
{
        struct ieee80211_hdr_4addr *hdr11;

        hdr11 = (struct ieee80211_hdr_4addr *) skb->data;
        switch (le16_to_cpu(hdr11->frame_ctl) &
                (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
        case IEEE80211_FCTL_TODS:
                memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
                memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
                break;
        case IEEE80211_FCTL_FROMDS:
                memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
                memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */
                break;
        case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS:
                memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
                memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */
                break;
        case 0:
                memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
                memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
                break;
        }

        hdr[12] = 0; /* priority */

        hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */
}


static int ieee80211_michael_mic_add(struct sk_buff *skb, int hdr_len, void *priv)
{
        struct ieee80211_tkip_data *tkey = priv;
        u8 *pos;
        struct ieee80211_hdr_4addr *hdr;

        hdr = (struct ieee80211_hdr_4addr *) skb->data;

        if (skb_tailroom(skb) < 8 || skb->len < hdr_len) {
                printk(KERN_DEBUG "Invalid packet for Michael MIC add "
                       "(tailroom=%d hdr_len=%d skb->len=%d)\n",
                       skb_tailroom(skb), hdr_len, skb->len);
                return -1;
        }

        michael_mic_hdr(skb, tkey->tx_hdr);

        // { david, 2006.9.1
        // fix the wpa process with wmm enabled.
        if(IEEE80211_QOS_HAS_SEQ(le16_to_cpu(hdr->frame_ctl))) {
                tkey->tx_hdr[12] = *(skb->data + hdr_len - 2) & 0x07;
        }
        // }
        pos = skb_put(skb, 8);
#if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
        if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
                                skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
#else
        if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
                                skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
#endif
                return -1;

        return 0;
}


#if WIRELESS_EXT >= 18
static void ieee80211_michael_mic_failure(struct net_device *dev,
                                       struct ieee80211_hdr_4addr *hdr,
                                       int keyidx)
{
        union iwreq_data wrqu;
        struct iw_michaelmicfailure ev;

        /* TODO: needed parameters: count, keyid, key type, TSC */
        memset(&ev, 0, sizeof(ev));
        ev.flags = keyidx & IW_MICFAILURE_KEY_ID;
        if (hdr->addr1[0] & 0x01)
                ev.flags |= IW_MICFAILURE_GROUP;
        else
                ev.flags |= IW_MICFAILURE_PAIRWISE;
        ev.src_addr.sa_family = ARPHRD_ETHER;
        memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN);
        memset(&wrqu, 0, sizeof(wrqu));
        wrqu.data.length = sizeof(ev);
        wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *) &ev);
}
#elif WIRELESS_EXT >= 15
static void ieee80211_michael_mic_failure(struct net_device *dev,
                                       struct ieee80211_hdr_4addr *hdr,
                                       int keyidx)
{
        union iwreq_data wrqu;
        char buf[128];

        /* TODO: needed parameters: count, keyid, key type, TSC */
        sprintf(buf, "MLME-MICHAELMICFAILURE.indication(keyid=%d %scast addr="
                MAC_FMT ")", keyidx, hdr->addr1[0] & 0x01 ? "broad" : "uni",
                MAC_ARG(hdr->addr2));
        memset(&wrqu, 0, sizeof(wrqu));
        wrqu.data.length = strlen(buf);
        wireless_send_event(dev, IWEVCUSTOM, &wrqu, buf);
}
#else /* WIRELESS_EXT >= 15 */
static inline void ieee80211_michael_mic_failure(struct net_device *dev,
                                              struct ieee80211_hdr_4addr *hdr,
                                              int keyidx)
{
}
#endif /* WIRELESS_EXT >= 15 */

static int ieee80211_michael_mic_verify(struct sk_buff *skb, int keyidx,
                                     int hdr_len, void *priv)
{
        struct ieee80211_tkip_data *tkey = priv;
        u8 mic[8];
        struct ieee80211_hdr_4addr *hdr;

        hdr = (struct ieee80211_hdr_4addr *) skb->data;

        if (!tkey->key_set)
                return -1;

        michael_mic_hdr(skb, tkey->rx_hdr);
        // { david, 2006.9.1
        // fix the wpa process with wmm enabled.
        if(IEEE80211_QOS_HAS_SEQ(le16_to_cpu(hdr->frame_ctl))) {
                tkey->rx_hdr[12] = *(skb->data + hdr_len - 2) & 0x07;
        }
        // }

#if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
        if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr,
                                skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
#else
        if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr,
                                skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
#endif
                return -1;
        if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) {
                struct ieee80211_hdr_4addr *hdr;
                hdr = (struct ieee80211_hdr_4addr *) skb->data;
                printk(KERN_DEBUG "%s: Michael MIC verification failed for "
                       "MSDU from " MAC_FMT " keyidx=%d\n",
                       skb->dev ? skb->dev->name : "N/A", MAC_ARG(hdr->addr2),
                       keyidx);
                if (skb->dev)
                        ieee80211_michael_mic_failure(skb->dev, hdr, keyidx);
                tkey->dot11RSNAStatsTKIPLocalMICFailures++;
                return -1;
        }

        /* Update TSC counters for RX now that the packet verification has
         * completed. */
        tkey->rx_iv32 = tkey->rx_iv32_new;
        tkey->rx_iv16 = tkey->rx_iv16_new;

        skb_trim(skb, skb->len - 8);

        return 0;
}


static int ieee80211_tkip_set_key(void *key, int len, u8 *seq, void *priv)
{
        struct ieee80211_tkip_data *tkey = priv;
        int keyidx;
#if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
        struct crypto_tfm *tfm = tkey->tx_tfm_michael;
        struct crypto_tfm *tfm2 = tkey->tx_tfm_arc4;
        struct crypto_tfm *tfm3 = tkey->rx_tfm_michael;
        struct crypto_tfm *tfm4 = tkey->rx_tfm_arc4;
#else
        struct crypto_hash *tfm = tkey->tx_tfm_michael;
        struct crypto_blkcipher *tfm2 = tkey->tx_tfm_arc4;
        struct crypto_hash *tfm3 = tkey->rx_tfm_michael;
        struct crypto_blkcipher *tfm4 = tkey->rx_tfm_arc4;
#endif

        keyidx = tkey->key_idx;
        memset(tkey, 0, sizeof(*tkey));
        tkey->key_idx = keyidx;
#if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
        tkey->tx_tfm_michael = tfm;
        tkey->tx_tfm_arc4 = tfm2;
        tkey->rx_tfm_michael = tfm3;
        tkey->rx_tfm_arc4 = tfm4;
#else
        tkey->tx_tfm_michael = tfm;
        tkey->tx_tfm_arc4 = tfm2;
        tkey->rx_tfm_michael = tfm3;
        tkey->rx_tfm_arc4 = tfm4;
#endif

        if (len == TKIP_KEY_LEN) {
                memcpy(tkey->key, key, TKIP_KEY_LEN);
                tkey->key_set = 1;
                tkey->tx_iv16 = 1; /* TSC is initialized to 1 */
                if (seq) {
                        tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) |
                                (seq[3] << 8) | seq[2];
                        tkey->rx_iv16 = (seq[1] << 8) | seq[0];
                }
        } else if (len == 0)
                tkey->key_set = 0;
        else
                return -1;

        return 0;
}


static int ieee80211_tkip_get_key(void *key, int len, u8 *seq, void *priv)
{
        struct ieee80211_tkip_data *tkey = priv;

        if (len < TKIP_KEY_LEN)
                return -1;

        if (!tkey->key_set)
                return 0;
        memcpy(key, tkey->key, TKIP_KEY_LEN);

        if (seq) {
                /* Return the sequence number of the last transmitted frame. */
                u16 iv16 = tkey->tx_iv16;
                u32 iv32 = tkey->tx_iv32;
                if (iv16 == 0)
                        iv32--;
                iv16--;
                seq[0] = tkey->tx_iv16;
                seq[1] = tkey->tx_iv16 >> 8;
                seq[2] = tkey->tx_iv32;
                seq[3] = tkey->tx_iv32 >> 8;
                seq[4] = tkey->tx_iv32 >> 16;
                seq[5] = tkey->tx_iv32 >> 24;
        }

        return TKIP_KEY_LEN;
}


static char * ieee80211_tkip_print_stats(char *p, void *priv)
{
        struct ieee80211_tkip_data *tkip = priv;
        p += sprintf(p, "key[%d] alg=TKIP key_set=%d "
                     "tx_pn=%02x%02x%02x%02x%02x%02x "
                     "rx_pn=%02x%02x%02x%02x%02x%02x "
                     "replays=%d icv_errors=%d local_mic_failures=%d\n",
                     tkip->key_idx, tkip->key_set,
                     (tkip->tx_iv32 >> 24) & 0xff,
                     (tkip->tx_iv32 >> 16) & 0xff,
                     (tkip->tx_iv32 >> 8) & 0xff,
                     tkip->tx_iv32 & 0xff,
                     (tkip->tx_iv16 >> 8) & 0xff,
                     tkip->tx_iv16 & 0xff,
                     (tkip->rx_iv32 >> 24) & 0xff,
                     (tkip->rx_iv32 >> 16) & 0xff,
                     (tkip->rx_iv32 >> 8) & 0xff,
                     tkip->rx_iv32 & 0xff,
                     (tkip->rx_iv16 >> 8) & 0xff,
                     tkip->rx_iv16 & 0xff,
                     tkip->dot11RSNAStatsTKIPReplays,
                     tkip->dot11RSNAStatsTKIPICVErrors,
                     tkip->dot11RSNAStatsTKIPLocalMICFailures);
        return p;
}


static struct ieee80211_crypto_ops ieee80211_crypt_tkip = {
        .name                   = "TKIP",
        .init                   = ieee80211_tkip_init,
        .deinit                 = ieee80211_tkip_deinit,
        .encrypt_mpdu           = ieee80211_tkip_encrypt,
        .decrypt_mpdu           = ieee80211_tkip_decrypt,
        .encrypt_msdu           = ieee80211_michael_mic_add,
        .decrypt_msdu           = ieee80211_michael_mic_verify,
        .set_key                = ieee80211_tkip_set_key,
        .get_key                = ieee80211_tkip_get_key,

        .print_stats            = ieee80211_tkip_print_stats,
        .extra_prefix_len       = 4 + 4, /* IV + ExtIV */
        .extra_postfix_len      = 8 + 4, /* MIC + ICV */
        .owner                  = THIS_MODULE,
};


int __init ieee80211_crypto_tkip_init(void)
{
        return ieee80211_register_crypto_ops(&ieee80211_crypt_tkip);
}


void __exit ieee80211_crypto_tkip_exit(void)
{
        ieee80211_unregister_crypto_ops(&ieee80211_crypt_tkip);
}

void ieee80211_tkip_null(void)
{
//    printk("============>%s()\n", __FUNCTION__);
        return;
}
#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
//EXPORT_SYMBOL(ieee80211_tkip_null);
#else
EXPORT_SYMBOL_NOVERS(ieee80211_tkip_null);
#endif

//module_init(ieee80211_crypto_tkip_init);
//module_exit(ieee80211_crypto_tkip_exit);