// SPDX-License-Identifier: GPL-2.0-only
/*
 * libipw crypt: host-based TKIP encryption implementation for libipw
 *
 * Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
 * Copyright (c) 2008, John W. Linville <linville@tuxdriver.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/err.h>
#include <linux/fips.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/scatterlist.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/mm.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>
#include <asm/string.h>
#include <linux/wireless.h>
#include <linux/ieee80211.h>
#include <net/iw_handler.h>
#include <crypto/arc4.h>
#include <crypto/hash.h>
#include <linux/crypto.h>
#include <linux/crc32.h>
#include "libipw.h"

#define TKIP_HDR_LEN 8

struct libipw_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;

        struct arc4_ctx rx_ctx_arc4;
        struct arc4_ctx tx_ctx_arc4;
        struct crypto_shash *rx_tfm_michael;
        struct crypto_shash *tx_tfm_michael;

        /* scratch buffers for virt_to_page() (crypto API) */
        u8 rx_hdr[16], tx_hdr[16];

        unsigned long flags;
};

static unsigned long libipw_tkip_set_flags(unsigned long flags, void *priv)
{
        struct libipw_tkip_data *_priv = priv;
        unsigned long old_flags = _priv->flags;
        _priv->flags = flags;
        return old_flags;
}

static unsigned long libipw_tkip_get_flags(void *priv)
{
        struct libipw_tkip_data *_priv = priv;
        return _priv->flags;
}

static void *libipw_tkip_init(int key_idx)
{
        struct libipw_tkip_data *priv;

        if (fips_enabled)
                return NULL;

        priv = kzalloc_obj(*priv, GFP_ATOMIC);
        if (priv == NULL)
                goto fail;

        priv->key_idx = key_idx;

        priv->tx_tfm_michael = crypto_alloc_shash("michael_mic", 0, 0);
        if (IS_ERR(priv->tx_tfm_michael)) {
                priv->tx_tfm_michael = NULL;
                goto fail;
        }

        priv->rx_tfm_michael = crypto_alloc_shash("michael_mic", 0, 0);
        if (IS_ERR(priv->rx_tfm_michael)) {
                priv->rx_tfm_michael = NULL;
                goto fail;
        }

        return priv;

      fail:
        if (priv) {
                crypto_free_shash(priv->tx_tfm_michael);
                crypto_free_shash(priv->rx_tfm_michael);
                kfree(priv);
        }

        return NULL;
}

static void libipw_tkip_deinit(void *priv)
{
        struct libipw_tkip_data *_priv = priv;
        if (_priv) {
                crypto_free_shash(_priv->tx_tfm_michael);
                crypto_free_shash(_priv->rx_tfm_michael);
        }
        kfree_sensitive(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(__le16 * 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((__le16 *) & TK[0]));
        PPK[1] += _S_(PPK[0] ^ Mk16_le((__le16 *) & TK[2]));
        PPK[2] += _S_(PPK[1] ^ Mk16_le((__le16 *) & TK[4]));
        PPK[3] += _S_(PPK[2] ^ Mk16_le((__le16 *) & TK[6]));
        PPK[4] += _S_(PPK[3] ^ Mk16_le((__le16 *) & TK[8]));
        PPK[5] += _S_(PPK[4] ^ Mk16_le((__le16 *) & TK[10]));

        PPK[0] += RotR1(PPK[5] ^ Mk16_le((__le16 *) & TK[12]));
        PPK[1] += RotR1(PPK[0] ^ Mk16_le((__le16 *) & 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((__le16 *) & 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 libipw_tkip_hdr(struct sk_buff *skb, int hdr_len,
                              u8 * rc4key, int keylen, void *priv)
{
        struct libipw_tkip_data *tkey = priv;
        u8 *pos;
        struct ieee80211_hdr *hdr;

        hdr = (struct ieee80211_hdr *)skb->data;

        if (skb_headroom(skb) < TKIP_HDR_LEN || skb->len < hdr_len)
                return -1;

        if (rc4key == NULL || keylen < 16)
                return -1;

        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);

        pos = skb_push(skb, TKIP_HDR_LEN);
        memmove(pos, pos + TKIP_HDR_LEN, hdr_len);
        pos += hdr_len;

        *pos++ = *rc4key;
        *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;

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

        return TKIP_HDR_LEN;
}

static int libipw_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
        struct libipw_tkip_data *tkey = priv;
        int len;
        u8 rc4key[16], *pos, *icv;
        u32 crc;

        if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
                struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
                net_dbg_ratelimited("TKIP countermeasures: dropped TX packet to %pM\n",
                                    hdr->addr1);
                return -1;
        }

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

        len = skb->len - hdr_len;
        pos = skb->data + hdr_len;

        if ((libipw_tkip_hdr(skb, hdr_len, rc4key, 16, priv)) < 0)
                return -1;

        crc = ~crc32_le(~0, pos, len);
        icv = skb_put(skb, 4);
        icv[0] = crc;
        icv[1] = crc >> 8;
        icv[2] = crc >> 16;
        icv[3] = crc >> 24;

        arc4_setkey(&tkey->tx_ctx_arc4, rc4key, 16);
        arc4_crypt(&tkey->tx_ctx_arc4, pos, pos, len + 4);

        return 0;
}

/*
 * deal with seq counter wrapping correctly.
 * refer to timer_after() for jiffies wrapping handling
 */
static inline int tkip_replay_check(u32 iv32_n, u16 iv16_n,
                                    u32 iv32_o, u16 iv16_o)
{
        if ((s32)iv32_n - (s32)iv32_o < 0 ||
            (iv32_n == iv32_o && iv16_n <= iv16_o))
                return 1;
        return 0;
}

static int libipw_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
        struct libipw_tkip_data *tkey = priv;
        u8 rc4key[16];
        u8 keyidx, *pos;
        u32 iv32;
        u16 iv16;
        struct ieee80211_hdr *hdr;
        u8 icv[4];
        u32 crc;
        int plen;

        hdr = (struct ieee80211_hdr *)skb->data;

        if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
                net_dbg_ratelimited("TKIP countermeasures: dropped received packet from %pM\n",
                                    hdr->addr2);
                return -1;
        }

        if (skb->len < hdr_len + TKIP_HDR_LEN + 4)
                return -1;

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

        if (tkip_replay_check(iv32, iv16, tkey->rx_iv32, tkey->rx_iv16)) {
#ifdef CONFIG_LIBIPW_DEBUG
                net_dbg_ratelimited("TKIP: replay detected: STA=%pM previous TSC %08x%04x received TSC %08x%04x\n",
                                    hdr->addr2, tkey->rx_iv32, tkey->rx_iv16,
                                    iv32, iv16);
#endif
                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;

        arc4_setkey(&tkey->rx_ctx_arc4, rc4key, 16);
        arc4_crypt(&tkey->rx_ctx_arc4, pos, pos, plen + 4);

        crc = ~crc32_le(~0, pos, plen);
        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;
                }
#ifdef CONFIG_LIBIPW_DEBUG
                net_dbg_ratelimited("TKIP: ICV error detected: STA=%pM\n",
                                    hdr->addr2);
#endif
                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 + TKIP_HDR_LEN, skb->data, hdr_len);
        skb_pull(skb, TKIP_HDR_LEN);
        skb_trim(skb, skb->len - 4);

        return keyidx;
}

static int michael_mic(struct crypto_shash *tfm_michael, u8 *key, u8 *hdr,
                       u8 *data, size_t data_len, u8 *mic)
{
        SHASH_DESC_ON_STACK(desc, tfm_michael);
        int err;

        if (tfm_michael == NULL) {
                pr_warn("%s(): tfm_michael == NULL\n", __func__);
                return -1;
        }

        desc->tfm = tfm_michael;

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

        err = crypto_shash_init(desc);
        if (err)
                goto out;
        err = crypto_shash_update(desc, hdr, 16);
        if (err)
                goto out;
        err = crypto_shash_update(desc, data, data_len);
        if (err)
                goto out;
        err = crypto_shash_final(desc, mic);

out:
        shash_desc_zero(desc);
        return err;
}

static void michael_mic_hdr(struct sk_buff *skb, u8 * hdr)
{
        struct ieee80211_hdr *hdr11;

        hdr11 = (struct ieee80211_hdr *)skb->data;

        switch (le16_to_cpu(hdr11->frame_control) &
                (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;
        default:
                memcpy(hdr, hdr11->addr1, ETH_ALEN);    /* DA */
                memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
                break;
        }

        if (ieee80211_is_data_qos(hdr11->frame_control)) {
                hdr[12] = le16_to_cpu(*((__le16 *)ieee80211_get_qos_ctl(hdr11)))
                        & IEEE80211_QOS_CTL_TID_MASK;
        } else
                hdr[12] = 0;            /* priority */

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

static int libipw_michael_mic_add(struct sk_buff *skb, int hdr_len,
                                     void *priv)
{
        struct libipw_tkip_data *tkey = priv;
        u8 *pos;

        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);
        pos = skb_put(skb, 8);
        if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
                        skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
                return -1;

        return 0;
}

static void libipw_michael_mic_failure(struct net_device *dev,
                                          struct ieee80211_hdr *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);
}

static int libipw_michael_mic_verify(struct sk_buff *skb, int keyidx,
                                        int hdr_len, void *priv)
{
        struct libipw_tkip_data *tkey = priv;
        u8 mic[8];

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

        michael_mic_hdr(skb, tkey->rx_hdr);
        if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr,
                        skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
                return -1;
        if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) {
                struct ieee80211_hdr *hdr;
                hdr = (struct ieee80211_hdr *)skb->data;
                printk(KERN_DEBUG "%s: Michael MIC verification failed for "
                       "MSDU from %pM keyidx=%d\n",
                       skb->dev ? skb->dev->name : "N/A", hdr->addr2,
                       keyidx);
                if (skb->dev)
                        libipw_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 libipw_tkip_set_key(void *key, int len, u8 * seq, void *priv)
{
        struct libipw_tkip_data *tkey = priv;
        int keyidx;
        struct crypto_shash *tfm = tkey->tx_tfm_michael;
        struct arc4_ctx *tfm2 = &tkey->tx_ctx_arc4;
        struct crypto_shash *tfm3 = tkey->rx_tfm_michael;
        struct arc4_ctx *tfm4 = &tkey->rx_ctx_arc4;

        keyidx = tkey->key_idx;
        memset(tkey, 0, sizeof(*tkey));
        tkey->key_idx = keyidx;
        tkey->tx_tfm_michael = tfm;
        tkey->tx_ctx_arc4 = *tfm2;
        tkey->rx_tfm_michael = tfm3;
        tkey->rx_ctx_arc4 = *tfm4;
        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 libipw_tkip_get_key(void *key, int len, u8 * seq, void *priv)
{
        struct libipw_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) {
                /*
                 * Not clear if this should return the value as is
                 * or - as the code previously seemed to partially
                 * have been written as - subtract one from it. It
                 * was working this way for a long time so leave it.
                 */
                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 void libipw_tkip_print_stats(struct seq_file *m, void *priv)
{
        struct libipw_tkip_data *tkip = priv;
        seq_printf(m,
                   "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);
}

static const struct libipw_crypto_ops libipw_crypt_tkip = {
        .name = "TKIP",
        .init = libipw_tkip_init,
        .deinit = libipw_tkip_deinit,
        .encrypt_mpdu = libipw_tkip_encrypt,
        .decrypt_mpdu = libipw_tkip_decrypt,
        .encrypt_msdu = libipw_michael_mic_add,
        .decrypt_msdu = libipw_michael_mic_verify,
        .set_key = libipw_tkip_set_key,
        .get_key = libipw_tkip_get_key,
        .print_stats = libipw_tkip_print_stats,
        .extra_mpdu_prefix_len = 4 + 4, /* IV + ExtIV */
        .extra_mpdu_postfix_len = 4,    /* ICV */
        .extra_msdu_postfix_len = 8,    /* MIC */
        .get_flags = libipw_tkip_get_flags,
        .set_flags = libipw_tkip_set_flags,
        .owner = THIS_MODULE,
};

int __init libipw_crypto_tkip_init(void)
{
        return libipw_register_crypto_ops(&libipw_crypt_tkip);
}

void libipw_crypto_tkip_exit(void)
{
        libipw_unregister_crypto_ops(&libipw_crypt_tkip);
}