Quelle  xxhash_generic.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0

#include <crypto/internal/hash.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/xxhash.h>
#include <linux/unaligned.h>

#define XXHASH64_BLOCK_SIZE 32
#define XXHASH64_DIGEST_SIZE 8

struct xxhash64_tfm_ctx {
 u64 seed;
};

struct xxhash64_desc_ctx {
 struct xxh64_state xxhstate;
};

static int xxhash64_setkey(struct crypto_shash *tfm, const u8 *key,
    unsigned int keylen)
{
 struct xxhash64_tfm_ctx *tctx = crypto_shash_ctx(tfm);

 if (keylen != sizeof(tctx->seed))
  return -EINVAL;
 tctx->seed = get_unaligned_le64(key);
 return 0;
}

static int xxhash64_init(struct shash_desc *desc)
{
 struct xxhash64_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
 struct xxhash64_desc_ctx *dctx = shash_desc_ctx(desc);

 xxh64_reset(&dctx->xxhstate, tctx->seed);

 return 0;
}

static int xxhash64_update(struct shash_desc *desc, const u8 *data,
    unsigned int length)
{
 struct xxhash64_desc_ctx *dctx = shash_desc_ctx(desc);

 xxh64_update(&dctx->xxhstate, data, length);

 return 0;
}

static int xxhash64_final(struct shash_desc *desc, u8 *out)
{
 struct xxhash64_desc_ctx *dctx = shash_desc_ctx(desc);

 put_unaligned_le64(xxh64_digest(&dctx->xxhstate), out);

 return 0;
}

static int xxhash64_digest(struct shash_desc *desc, const u8 *data,
    unsigned int length, u8 *out)
{
 struct xxhash64_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);

 put_unaligned_le64(xxh64(data, length, tctx->seed), out);

 return 0;
}

static struct shash_alg alg = {
 .digestsize = XXHASH64_DIGEST_SIZE,
 .setkey  = xxhash64_setkey,
 .init  = xxhash64_init,
 .update  = xxhash64_update,
 .final  = xxhash64_final,
 .digest  = xxhash64_digest,
 .descsize = sizeof(struct xxhash64_desc_ctx),
 .base  = {
  .cra_name  = "xxhash64",
  .cra_driver_name = "xxhash64-generic",
  .cra_priority  = 100,
  .cra_flags  = CRYPTO_ALG_OPTIONAL_KEY,
  .cra_blocksize  = XXHASH64_BLOCK_SIZE,
  .cra_ctxsize  = sizeof(struct xxhash64_tfm_ctx),
  .cra_module  = THIS_MODULE,
 }
};

static int __init xxhash_mod_init(void)
{
 return crypto_register_shash(&alg);
}

static void __exit xxhash_mod_fini(void)
{
 crypto_unregister_shash(&alg);
}

module_init(xxhash_mod_init);
module_exit(xxhash_mod_fini);

MODULE_AUTHOR("Nikolay Borisov ");
MODULE_DESCRIPTION("xxhash calculations wrapper for lib/xxhash.c");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CRYPTO("xxhash64");
MODULE_ALIAS_CRYPTO("xxhash64-generic");