LXR linux/drivers/staging/lustre/lustre/libcfs/linux/linux-crypto-adler.c

   1/* GPL HEADER START
   2 *
   3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License version 2 only,
   7 * as published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it will be useful, but
  10 * WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 * General Public License version 2 for more details (a copy is included
  13 * in the LICENSE file that accompanied this code).
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * version 2 along with this program; If not, see http://www.gnu.org/licenses
  17 *
  18 * Please  visit http://www.xyratex.com/contact if you need additional
  19 * information or have any questions.
  20 *
  21 * GPL HEADER END
  22 */
  23
  24/*
  25 * Copyright 2012 Xyratex Technology Limited
  26 */
  27
  28/*
  29 * This is crypto api shash wrappers to zlib_adler32.
  30 */
  31
  32#include <linux/module.h>
  33#include <linux/zutil.h>
  34#include <crypto/internal/hash.h>
  35
  36
  37#define CHKSUM_BLOCK_SIZE       1
  38#define CHKSUM_DIGEST_SIZE      4
  39
  40
  41static u32 __adler32(u32 cksum, unsigned char const *p, size_t len)
  42{
  43        return zlib_adler32(cksum, p, len);
  44}
  45
  46static int adler32_cra_init(struct crypto_tfm *tfm)
  47{
  48        u32 *key = crypto_tfm_ctx(tfm);
  49
  50        *key = 1;
  51
  52        return 0;
  53}
  54
  55static int adler32_setkey(struct crypto_shash *hash, const u8 *key,
  56                          unsigned int keylen)
  57{
  58        u32 *mctx = crypto_shash_ctx(hash);
  59
  60        if (keylen != sizeof(u32)) {
  61                crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
  62                return -EINVAL;
  63        }
  64        *mctx = *(u32 *)key;
  65        return 0;
  66}
  67
  68static int adler32_init(struct shash_desc *desc)
  69{
  70        u32 *mctx = crypto_shash_ctx(desc->tfm);
  71        u32 *cksump = shash_desc_ctx(desc);
  72
  73        *cksump = *mctx;
  74
  75        return 0;
  76}
  77
  78static int adler32_update(struct shash_desc *desc, const u8 *data,
  79                          unsigned int len)
  80{
  81        u32 *cksump = shash_desc_ctx(desc);
  82
  83        *cksump = __adler32(*cksump, data, len);
  84        return 0;
  85}
  86static int __adler32_finup(u32 *cksump, const u8 *data, unsigned int len,
  87                           u8 *out)
  88{
  89        *(u32 *)out = __adler32(*cksump, data, len);
  90        return 0;
  91}
  92
  93static int adler32_finup(struct shash_desc *desc, const u8 *data,
  94                         unsigned int len, u8 *out)
  95{
  96        return __adler32_finup(shash_desc_ctx(desc), data, len, out);
  97}
  98
  99static int adler32_final(struct shash_desc *desc, u8 *out)
 100{
 101        u32 *cksump = shash_desc_ctx(desc);
 102
 103        *(u32 *)out = *cksump;
 104        return 0;
 105}
 106
 107static int adler32_digest(struct shash_desc *desc, const u8 *data,
 108                          unsigned int len, u8 *out)
 109{
 110        return __adler32_finup(crypto_shash_ctx(desc->tfm), data, len,
 111                                    out);
 112}
 113static struct shash_alg alg = {
 114        .setkey         = adler32_setkey,
 115        .init           = adler32_init,
 116        .update         = adler32_update,
 117        .final          = adler32_final,
 118        .finup          = adler32_finup,
 119        .digest         = adler32_digest,
 120        .descsize       = sizeof(u32),
 121        .digestsize     = CHKSUM_DIGEST_SIZE,
 122        .base           = {
 123                .cra_name               = "adler32",
 124                .cra_driver_name        = "adler32-zlib",
 125                .cra_priority           = 100,
 126                .cra_blocksize          = CHKSUM_BLOCK_SIZE,
 127                .cra_ctxsize            = sizeof(u32),
 128                .cra_module             = THIS_MODULE,
 129                .cra_init               = adler32_cra_init,
 130        }
 131};
 132
 133
 134int cfs_crypto_adler32_register(void)
 135{
 136        return crypto_register_shash(&alg);
 137}
 138EXPORT_SYMBOL(cfs_crypto_adler32_register);
 139
 140void cfs_crypto_adler32_unregister(void)
 141{
 142        crypto_unregister_shash(&alg);
 143}
 144EXPORT_SYMBOL(cfs_crypto_adler32_unregister);
 145