libcfs/libcfs/linux/linux-crypto-crc32.c

   1 /* GPL HEADER START
   2  *
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
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   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 crc32_le.
  30  */
  31
  32 #include <linux/crc32.h>
  33 #ifdef HAVE_STRUCT_SHASH_ALG
  34 #include <crypto/internal/hash.h>
  35 #else
  36 #include <linux/crypto.h>
  37 #endif
  38
  39 #define CHKSUM_BLOCK_SIZE       1
  40 #define CHKSUM_DIGEST_SIZE      4
  41
  42 static u32 __crc32_le(u32 crc, unsigned char const *p, size_t len)
  43 {
  44         return crc32_le(crc, p, len);
  45 }
  46
  47 /** No default init with ~0 */
  48 static int crc32_cra_init(struct crypto_tfm *tfm)
  49 {
  50         u32 *key = crypto_tfm_ctx(tfm);
  51
  52         *key = 0;
  53
  54         return 0;
  55 }
  56
  57
  58 #ifdef HAVE_STRUCT_SHASH_ALG
  59 /*
  60  * Setting the seed allows arbitrary accumulators and flexible XOR policy
  61  * If your algorithm starts with ~0, then XOR with ~0 before you set
  62  * the seed.
  63  */
  64 static int crc32_setkey(struct crypto_shash *hash, const u8 *key,
  65                         unsigned int keylen)
  66 {
  67         u32 *mctx = crypto_shash_ctx(hash);
  68
  69         if (keylen != sizeof(u32)) {
  70                 crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
  71                 return -EINVAL;
  72         }
  73         *mctx = le32_to_cpup((__le32 *)key);
  74         return 0;
  75 }
  76
  77 static int crc32_init(struct shash_desc *desc)
  78 {
  79         u32 *mctx = crypto_shash_ctx(desc->tfm);
  80         u32 *crcp = shash_desc_ctx(desc);
  81
  82         *crcp = *mctx;
  83
  84         return 0;
  85 }
  86
  87 static int crc32_update(struct shash_desc *desc, const u8 *data,
  88                         unsigned int len)
  89 {
  90         u32 *crcp = shash_desc_ctx(desc);
  91
  92         *crcp = __crc32_le(*crcp, data, len);
  93         return 0;
  94 }
  95 /* No final XOR 0xFFFFFFFF, like crc32_le */
  96 static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len,
  97                          u8 *out)
  98 {
  99         *(__le32 *)out = cpu_to_le32(__crc32_le(*crcp, data, len));
 100         return 0;
 101 }
 102
 103 static int crc32_finup(struct shash_desc *desc, const u8 *data,
 104                        unsigned int len, u8 *out)
 105 {
 106         return __crc32_finup(shash_desc_ctx(desc), data, len, out);
 107 }
 108
 109 static int crc32_final(struct shash_desc *desc, u8 *out)
 110 {
 111         u32 *crcp = shash_desc_ctx(desc);
 112
 113         *(__le32 *)out = cpu_to_le32p(crcp);
 114         return 0;
 115 }
 116
 117 static int crc32_digest(struct shash_desc *desc, const u8 *data,
 118                         unsigned int len, u8 *out)
 119 {
 120         return __crc32_finup(crypto_shash_ctx(desc->tfm), data, len,
 121                              out);
 122 }
 123 static struct shash_alg alg = {
 124         .setkey         = crc32_setkey,
 125         .init           = crc32_init,
 126         .update         = crc32_update,
 127         .final          = crc32_final,
 128         .finup          = crc32_finup,
 129         .digest         = crc32_digest,
 130         .descsize       = sizeof(u32),
 131         .digestsize     = CHKSUM_DIGEST_SIZE,
 132         .base           = {
 133                 .cra_name               = "crc32",
 134                 .cra_driver_name        = "crc32-table",
 135                 .cra_priority           = 100,
 136                 .cra_blocksize          = CHKSUM_BLOCK_SIZE,
 137                 .cra_ctxsize            = sizeof(u32),
 138                 .cra_module             = THIS_MODULE,
 139                 .cra_init               = crc32_cra_init,
 140         }
 141 };
 142 #else   /* HAVE_STRUCT_SHASH_ALG */
 143 #ifdef HAVE_DIGEST_SETKEY_FLAGS
 144 static int crc32_digest_setkey(struct crypto_tfm *tfm, const u8 *key,
 145                                unsigned int keylen, unsigned int *flags)
 146 #else
 147 static int crc32_digest_setkey(struct crypto_tfm *tfm, const u8 *key,
 148                                unsigned int keylen)
 149 #endif
 150 {
 151         u32 *mctx = crypto_tfm_ctx(tfm);
 152
 153         if (keylen != sizeof(u32)) {
 154                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 155                 return -EINVAL;
 156         }
 157         *mctx = le32_to_cpup((__le32 *)key);
 158         return 0;
 159 }
 160
 161 static void crc32_digest_init(struct crypto_tfm *tfm)
 162 {
 163         u32 *mctx = crypto_tfm_ctx(tfm);
 164
 165         *mctx = 0;
 166
 167 }
 168 static void crc32_digest_update(struct crypto_tfm *tfm, const u8 *data,
 169                                 unsigned int len)
 170 {
 171         u32 *crcp = crypto_tfm_ctx(tfm);
 172
 173         *crcp = __crc32_le(*crcp, data, len);
 174 }
 175
 176 static void crc32_digest_final(struct crypto_tfm *tfm, u8 *out)
 177 {
 178         u32 *crcp = crypto_tfm_ctx(tfm);
 179
 180         *(__le32 *)out = cpu_to_le32p(crcp);
 181 }
 182
 183 static struct crypto_alg alg = {
 184         .cra_name               = "crc32",
 185         .cra_flags              = CRYPTO_ALG_TYPE_DIGEST,
 186         .cra_driver_name        = "crc32-table",
 187         .cra_priority           = 100,
 188         .cra_blocksize          = CHKSUM_BLOCK_SIZE,
 189         .cra_ctxsize            = sizeof(u32),
 190         .cra_module             = THIS_MODULE,
 191         .cra_init               = crc32_cra_init,
 192         .cra_list               = LIST_HEAD_INIT(alg.cra_list),
 193         .cra_u                  = {
 194                 .digest         = {
 195                         .dia_digestsize = CHKSUM_DIGEST_SIZE,
 196                         .dia_setkey     = crc32_digest_setkey,
 197                         .dia_init       = crc32_digest_init,
 198                         .dia_update     = crc32_digest_update,
 199                         .dia_final      = crc32_digest_final
 200                 }
 201         }
 202 };
 203 #endif  /* HAVE_STRUCT_SHASH_ALG */
 204
 205 int cfs_crypto_crc32_register(void)
 206 {
 207 #ifdef HAVE_STRUCT_SHASH_ALG
 208         return crypto_register_shash(&alg);
 209 #else
 210         return crypto_register_alg(&alg);
 211 #endif
 212 }
 213 EXPORT_SYMBOL(cfs_crypto_crc32_register);
 214
 215 void cfs_crypto_crc32_unregister(void)
 216 {
 217 #ifdef HAVE_STRUCT_SHASH_ALG
 218         crypto_unregister_shash(&alg);
 219 #else
 220         crypto_unregister_alg(&alg);
 221 #endif
 222 }
 223 EXPORT_SYMBOL(cfs_crypto_crc32_unregister);