cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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crc32_generic.c (2901B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright 2012 Xyratex Technology Limited
      4 */
      5
      6/*
      7 * This is crypto api shash wrappers to crc32_le.
      8 */
      9
     10#include <asm/unaligned.h>
     11#include <linux/crc32.h>
     12#include <crypto/internal/hash.h>
     13#include <linux/init.h>
     14#include <linux/module.h>
     15#include <linux/string.h>
     16#include <linux/kernel.h>
     17
     18#define CHKSUM_BLOCK_SIZE	1
     19#define CHKSUM_DIGEST_SIZE	4
     20
     21/** No default init with ~0 */
     22static int crc32_cra_init(struct crypto_tfm *tfm)
     23{
     24	u32 *key = crypto_tfm_ctx(tfm);
     25
     26	*key = 0;
     27
     28	return 0;
     29}
     30
     31/*
     32 * Setting the seed allows arbitrary accumulators and flexible XOR policy
     33 * If your algorithm starts with ~0, then XOR with ~0 before you set
     34 * the seed.
     35 */
     36static int crc32_setkey(struct crypto_shash *hash, const u8 *key,
     37			unsigned int keylen)
     38{
     39	u32 *mctx = crypto_shash_ctx(hash);
     40
     41	if (keylen != sizeof(u32))
     42		return -EINVAL;
     43	*mctx = get_unaligned_le32(key);
     44	return 0;
     45}
     46
     47static int crc32_init(struct shash_desc *desc)
     48{
     49	u32 *mctx = crypto_shash_ctx(desc->tfm);
     50	u32 *crcp = shash_desc_ctx(desc);
     51
     52	*crcp = *mctx;
     53
     54	return 0;
     55}
     56
     57static int crc32_update(struct shash_desc *desc, const u8 *data,
     58			unsigned int len)
     59{
     60	u32 *crcp = shash_desc_ctx(desc);
     61
     62	*crcp = crc32_le(*crcp, data, len);
     63	return 0;
     64}
     65
     66/* No final XOR 0xFFFFFFFF, like crc32_le */
     67static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len,
     68			 u8 *out)
     69{
     70	put_unaligned_le32(crc32_le(*crcp, data, len), out);
     71	return 0;
     72}
     73
     74static int crc32_finup(struct shash_desc *desc, const u8 *data,
     75		       unsigned int len, u8 *out)
     76{
     77	return __crc32_finup(shash_desc_ctx(desc), data, len, out);
     78}
     79
     80static int crc32_final(struct shash_desc *desc, u8 *out)
     81{
     82	u32 *crcp = shash_desc_ctx(desc);
     83
     84	put_unaligned_le32(*crcp, out);
     85	return 0;
     86}
     87
     88static int crc32_digest(struct shash_desc *desc, const u8 *data,
     89			unsigned int len, u8 *out)
     90{
     91	return __crc32_finup(crypto_shash_ctx(desc->tfm), data, len,
     92			     out);
     93}
     94static struct shash_alg alg = {
     95	.setkey		= crc32_setkey,
     96	.init		= crc32_init,
     97	.update		= crc32_update,
     98	.final		= crc32_final,
     99	.finup		= crc32_finup,
    100	.digest		= crc32_digest,
    101	.descsize	= sizeof(u32),
    102	.digestsize	= CHKSUM_DIGEST_SIZE,
    103	.base		= {
    104		.cra_name		= "crc32",
    105		.cra_driver_name	= "crc32-generic",
    106		.cra_priority		= 100,
    107		.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
    108		.cra_blocksize		= CHKSUM_BLOCK_SIZE,
    109		.cra_ctxsize		= sizeof(u32),
    110		.cra_module		= THIS_MODULE,
    111		.cra_init		= crc32_cra_init,
    112	}
    113};
    114
    115static int __init crc32_mod_init(void)
    116{
    117	return crypto_register_shash(&alg);
    118}
    119
    120static void __exit crc32_mod_fini(void)
    121{
    122	crypto_unregister_shash(&alg);
    123}
    124
    125subsys_initcall(crc32_mod_init);
    126module_exit(crc32_mod_fini);
    127
    128MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>");
    129MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32");
    130MODULE_LICENSE("GPL");
    131MODULE_ALIAS_CRYPTO("crc32");
    132MODULE_ALIAS_CRYPTO("crc32-generic");