[linux.git] / crypto / crc32_generic.c

/* GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see http://www.gnu.org/licenses
 *
 * Please  visit http://www.xyratex.com/contact if you need additional
 * information or have any questions.
 *
 * GPL HEADER END
 */

/*
 * Copyright 2012 Xyratex Technology Limited
 */

/*
 * This is crypto api shash wrappers to crc32_le.
 */

#include <asm/unaligned.h>
#include <linux/crc32.h>
#include <crypto/internal/hash.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/kernel.h>

#define CHKSUM_BLOCK_SIZE	1
#define CHKSUM_DIGEST_SIZE	4

/** No default init with ~0 */
static int crc32_cra_init(struct crypto_tfm *tfm)
{
	u32 *key = crypto_tfm_ctx(tfm);

	*key = 0;

	return 0;
}

/*
 * Setting the seed allows arbitrary accumulators and flexible XOR policy
 * If your algorithm starts with ~0, then XOR with ~0 before you set
 * the seed.
 */
static int crc32_setkey(struct crypto_shash *hash, const u8 *key,
			unsigned int keylen)
{
	u32 *mctx = crypto_shash_ctx(hash);

	if (keylen != sizeof(u32)) {
		crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
		return -EINVAL;
	}
	*mctx = get_unaligned_le32(key);
	return 0;
}

static int crc32_init(struct shash_desc *desc)
{
	u32 *mctx = crypto_shash_ctx(desc->tfm);
	u32 *crcp = shash_desc_ctx(desc);

	*crcp = *mctx;

	return 0;
}

static int crc32_update(struct shash_desc *desc, const u8 *data,
			unsigned int len)
{
	u32 *crcp = shash_desc_ctx(desc);

	*crcp = crc32_le(*crcp, data, len);
	return 0;
}

/* No final XOR 0xFFFFFFFF, like crc32_le */
static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len,
			 u8 *out)
{
	put_unaligned_le32(crc32_le(*crcp, data, len), out);
	return 0;
}

static int crc32_finup(struct shash_desc *desc, const u8 *data,
		       unsigned int len, u8 *out)
{
	return __crc32_finup(shash_desc_ctx(desc), data, len, out);
}

static int crc32_final(struct shash_desc *desc, u8 *out)
{
	u32 *crcp = shash_desc_ctx(desc);

	put_unaligned_le32(*crcp, out);
	return 0;
}

static int crc32_digest(struct shash_desc *desc, const u8 *data,
			unsigned int len, u8 *out)
{
	return __crc32_finup(crypto_shash_ctx(desc->tfm), data, len,
			     out);
}
static struct shash_alg alg = {
	.setkey		= crc32_setkey,
	.init		= crc32_init,
	.update		= crc32_update,
	.final		= crc32_final,
	.finup		= crc32_finup,
	.digest		= crc32_digest,
	.descsize	= sizeof(u32),
	.digestsize	= CHKSUM_DIGEST_SIZE,
	.base		= {
		.cra_name		= "crc32",
		.cra_driver_name	= "crc32-generic",
		.cra_priority		= 100,
		.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
		.cra_blocksize		= CHKSUM_BLOCK_SIZE,
		.cra_ctxsize		= sizeof(u32),
		.cra_module		= THIS_MODULE,
		.cra_init		= crc32_cra_init,
	}
};

static int __init crc32_mod_init(void)
{
	return crypto_register_shash(&alg);
}

static void __exit crc32_mod_fini(void)
{
	crypto_unregister_shash(&alg);
}

module_init(crc32_mod_init);
module_exit(crc32_mod_fini);

MODULE_AUTHOR("Alexander Boyko <[email protected]>");
MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CRYPTO("crc32");
MODULE_ALIAS_CRYPTO("crc32-generic");
Commit	Line	Data
78c37d19 AB	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 crc32_le.
	30	*/
	31
fffe7d92	32	#include <asm/unaligned.h>
78c37d19 AB	33	#include <linux/crc32.h>
	34	#include <crypto/internal/hash.h>
	35	#include <linux/init.h>
	36	#include <linux/module.h>
	37	#include <linux/string.h>
	38	#include <linux/kernel.h>
	39
	40	#define CHKSUM_BLOCK_SIZE 1
	41	#define CHKSUM_DIGEST_SIZE 4
	42
78c37d19 AB	43	/** No default init with ~0 */
	44	static int crc32_cra_init(struct crypto_tfm *tfm)
	45	{
	46	u32 *key = crypto_tfm_ctx(tfm);
	47
	48	*key = 0;
	49
	50	return 0;
	51	}
	52
78c37d19 AB	53	/*
	54	* Setting the seed allows arbitrary accumulators and flexible XOR policy
	55	* If your algorithm starts with ~0, then XOR with ~0 before you set
	56	* the seed.
	57	*/
	58	static int crc32_setkey(struct crypto_shash hash, const u8 key,
	59	unsigned int keylen)
	60	{
	61	u32 *mctx = crypto_shash_ctx(hash);
	62
	63	if (keylen != sizeof(u32)) {
	64	crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
	65	return -EINVAL;
	66	}
fffe7d92	67	*mctx = get_unaligned_le32(key);
78c37d19 AB	68	return 0;
	69	}
	70
	71	static int crc32_init(struct shash_desc *desc)
	72	{
	73	u32 *mctx = crypto_shash_ctx(desc->tfm);
	74	u32 *crcp = shash_desc_ctx(desc);
	75
	76	crcp = mctx;
	77
	78	return 0;
	79	}
	80
	81	static int crc32_update(struct shash_desc desc, const u8 data,
	82	unsigned int len)
	83	{
	84	u32 *crcp = shash_desc_ctx(desc);
	85
6943546c	86	crcp = crc32_le(crcp, data, len);
78c37d19 AB	87	return 0;
	88	}
	89
	90	/* No final XOR 0xFFFFFFFF, like crc32_le */
	91	static int __crc32_finup(u32 crcp, const u8 data, unsigned int len,
	92	u8 *out)
	93	{
6943546c	94	put_unaligned_le32(crc32_le(*crcp, data, len), out);
78c37d19 AB	95	return 0;
	96	}
	97
	98	static int crc32_finup(struct shash_desc desc, const u8 data,
	99	unsigned int len, u8 *out)
	100	{
	101	return __crc32_finup(shash_desc_ctx(desc), data, len, out);
	102	}
	103
	104	static int crc32_final(struct shash_desc desc, u8 out)
	105	{
	106	u32 *crcp = shash_desc_ctx(desc);
	107
fffe7d92	108	put_unaligned_le32(*crcp, out);
78c37d19 AB	109	return 0;
	110	}
	111
	112	static int crc32_digest(struct shash_desc desc, const u8 data,
	113	unsigned int len, u8 *out)
	114	{
	115	return __crc32_finup(crypto_shash_ctx(desc->tfm), data, len,
	116	out);
	117	}
	118	static struct shash_alg alg = {
	119	.setkey = crc32_setkey,
	120	.init = crc32_init,
	121	.update = crc32_update,
	122	.final = crc32_final,
	123	.finup = crc32_finup,
	124	.digest = crc32_digest,
	125	.descsize = sizeof(u32),
	126	.digestsize = CHKSUM_DIGEST_SIZE,
	127	.base = {
	128	.cra_name = "crc32",
a7c58ac0	129	.cra_driver_name = "crc32-generic",
78c37d19	130	.cra_priority = 100,
a208fa8f	131	.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
78c37d19 AB	132	.cra_blocksize = CHKSUM_BLOCK_SIZE,
	133	.cra_ctxsize = sizeof(u32),
	134	.cra_module = THIS_MODULE,
	135	.cra_init = crc32_cra_init,
	136	}
	137	};
	138
	139	static int __init crc32_mod_init(void)
	140	{
	141	return crypto_register_shash(&alg);
	142	}
	143
	144	static void __exit crc32_mod_fini(void)
	145	{
	146	crypto_unregister_shash(&alg);
	147	}
	148
	149	module_init(crc32_mod_init);
	150	module_exit(crc32_mod_fini);
	151
	152	MODULE_AUTHOR("Alexander Boyko <[email protected]>");
	153	MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32");
	154	MODULE_LICENSE("GPL");
5d26a105	155	MODULE_ALIAS_CRYPTO("crc32");
a7c58ac0	156	MODULE_ALIAS_CRYPTO("crc32-generic");