Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * Michael MIC implementation - optimized for TKIP MIC operations

 * Copyright 2002-2003, Instant802 Networks, Inc.

 *

 * 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.

 */

#include <linux/types.h>

#include "michael.h"

static inline u32 rotr(u32 val, int bits)

{

        return (val >> bits) | (val << (32 - bits));

}

static inline u32 rotl(u32 val, int bits)

{

        return (val << bits) | (val >> (32 - bits));

}

static inline u32 xswap(u32 val)

{

        return ((val & 0xff00ff00) >> 8) | ((val & 0x00ff00ff) << 8);

}

#define michael_block(l, r) \

do { \

        r ^= rotl(l, 17); \

        l += r; \

        r ^= xswap(l); \

        l += r; \

        r ^= rotl(l, 3); \

        l += r; \

        r ^= rotr(l, 2); \

        l += r; \

} while (0)

static inline u32 michael_get32(u8 *data)

{

        return data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);

}

static inline void michael_put32(u32 val, u8 *data)

{

        data[0] = val & 0xff;

        data[1] = (val >> 8) & 0xff;

        data[2] = (val >> 16) & 0xff;

        data[3] = (val >> 24) & 0xff;

}

void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority,

                 u8 *data, size_t data_len, u8 *mic)

{

        u32 l, r, val;

        size_t block, blocks, left;

        l = michael_get32(key);

        r = michael_get32(key + 4);

        /* A pseudo header (DA, SA, Priority, 0, 0, 0) is used in Michael MIC

         * calculation, but it is _not_ transmitted */

        l ^= michael_get32(da);

        michael_block(l, r);

        l ^= da[4] | (da[5] << 8) | (sa[0] << 16) | (sa[1] << 24);

        michael_block(l, r);

        l ^= michael_get32(&sa[2]);

        michael_block(l, r);

        l ^= priority;

        michael_block(l, r);

        /* Real data */

        blocks = data_len / 4;

        left = data_len % 4;

        for (block = 0; block < blocks; block++) {

                l ^= michael_get32(&data[block * 4]);

                michael_block(l, r);

        }

        /* Partial block of 0..3 bytes and padding: 0x5a + 4..7 zeros to make

         * total length a multiple of 4. */

        val = 0x5a;

        while (left > 0) {

                val <<= 8;

                left--;

                val |= data[blocks * 4 + left];

        }

        l ^= val;

        michael_block(l, r);

        /* last block is zero, so l ^ 0 = l */

        michael_block(l, r);

        michael_put32(l, mic);

        michael_put32(r, mic + 4);

}