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[/] [test_project/] [trunk/] [linux_sd_driver/] [crypto/] [michael_mic.c] - Blame information for rev 78

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Line No. Rev Author Line
1 62 marcus.erl 
/*
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 * Cryptographic API
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 *
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 * Michael MIC (IEEE 802.11i/TKIP) keyed digest
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 *
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 * Copyright (c) 2004 Jouni Malinen <j@w1.fi>
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 as
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 * published by the Free Software Foundation.
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 */
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#include <asm/byteorder.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/string.h>
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#include <linux/crypto.h>
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#include <linux/types.h>
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struct michael_mic_ctx {
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        u8 pending[4];
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        size_t pending_len;
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        u32 l, r;
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};
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static inline u32 xswap(u32 val)
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{
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        return ((val & 0x00ff00ff) << 8) | ((val & 0xff00ff00) >> 8);
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}
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#define michael_block(l, r)     \
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do {                            \
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        r ^= rol32(l, 17);      \
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        l += r;                 \
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        r ^= xswap(l);          \
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        l += r;                 \
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        r ^= rol32(l, 3);       \
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        l += r;                 \
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        r ^= ror32(l, 2);       \
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        l += r;                 \
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} while (0)
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static void michael_init(struct crypto_tfm *tfm)
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{
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        struct michael_mic_ctx *mctx = crypto_tfm_ctx(tfm);
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        mctx->pending_len = 0;
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}
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static void michael_update(struct crypto_tfm *tfm, const u8 *data,
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                           unsigned int len)
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{
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        struct michael_mic_ctx *mctx = crypto_tfm_ctx(tfm);
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        const __le32 *src;
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        if (mctx->pending_len) {
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                int flen = 4 - mctx->pending_len;
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                if (flen > len)
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                        flen = len;
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                memcpy(&mctx->pending[mctx->pending_len], data, flen);
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                mctx->pending_len += flen;
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                data += flen;
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                len -= flen;
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                if (mctx->pending_len < 4)
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                        return;
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                src = (const __le32 *)mctx->pending;
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                mctx->l ^= le32_to_cpup(src);
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                michael_block(mctx->l, mctx->r);
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                mctx->pending_len = 0;
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        }
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        src = (const __le32 *)data;
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        while (len >= 4) {
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                mctx->l ^= le32_to_cpup(src++);
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                michael_block(mctx->l, mctx->r);
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                len -= 4;
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        }
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        if (len > 0) {
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                mctx->pending_len = len;
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                memcpy(mctx->pending, src, len);
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        }
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}
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static void michael_final(struct crypto_tfm *tfm, u8 *out)
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{
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        struct michael_mic_ctx *mctx = crypto_tfm_ctx(tfm);
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        u8 *data = mctx->pending;
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        __le32 *dst = (__le32 *)out;
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        /* Last block and padding (0x5a, 4..7 x 0) */
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        switch (mctx->pending_len) {
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        case 0:
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                mctx->l ^= 0x5a;
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                break;
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        case 1:
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                mctx->l ^= data[0] | 0x5a00;
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                break;
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        case 2:
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                mctx->l ^= data[0] | (data[1] << 8) | 0x5a0000;
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                break;
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        case 3:
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                mctx->l ^= data[0] | (data[1] << 8) | (data[2] << 16) |
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                        0x5a000000;
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                break;
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        }
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        michael_block(mctx->l, mctx->r);
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        /* l ^= 0; */
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        michael_block(mctx->l, mctx->r);
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        dst[0] = cpu_to_le32(mctx->l);
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        dst[1] = cpu_to_le32(mctx->r);
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}
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static int michael_setkey(struct crypto_tfm *tfm, const u8 *key,
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                          unsigned int keylen)
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{
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        struct michael_mic_ctx *mctx = crypto_tfm_ctx(tfm);
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        const __le32 *data = (const __le32 *)key;
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        if (keylen != 8) {
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                tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
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                return -EINVAL;
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        }
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        mctx->l = le32_to_cpu(data[0]);
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        mctx->r = le32_to_cpu(data[1]);
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        return 0;
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}
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static struct crypto_alg michael_mic_alg = {
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        .cra_name       = "michael_mic",
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        .cra_flags      = CRYPTO_ALG_TYPE_DIGEST,
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        .cra_blocksize  = 8,
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        .cra_ctxsize    = sizeof(struct michael_mic_ctx),
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        .cra_module     = THIS_MODULE,
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        .cra_alignmask  = 3,
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        .cra_list       = LIST_HEAD_INIT(michael_mic_alg.cra_list),
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        .cra_u          = { .digest = {
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        .dia_digestsize = 8,
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        .dia_init       = michael_init,
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        .dia_update     = michael_update,
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        .dia_final      = michael_final,
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        .dia_setkey     = michael_setkey } }
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};
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static int __init michael_mic_init(void)
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{
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        return crypto_register_alg(&michael_mic_alg);
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}
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static void __exit michael_mic_exit(void)
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{
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        crypto_unregister_alg(&michael_mic_alg);
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}
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module_init(michael_mic_init);
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module_exit(michael_mic_exit);
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("Michael MIC");
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MODULE_AUTHOR("Jouni Malinen <j@w1.fi>");

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