[deliverable/linux.git] / crypto / crc32.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 <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

static u32 __crc32_le(u32 crc, unsigned char const *p, size_t len)
{
	return crc32_le(crc, p, len);
}

/** 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 = le32_to_cpup((__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)
{
	*(__le32 *)out = cpu_to_le32(__crc32_le(*crcp, data, len));
	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);

	*(__le32 *)out = cpu_to_le32p(crcp);
	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-table",
		.cra_priority		= 100,
		.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 <alexander_boyko@xyratex.com>");
MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CRYPTO("crc32");
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
	32	#include <linux/crc32.h>
	33	#include <crypto/internal/hash.h>
	34	#include <linux/init.h>
	35	#include <linux/module.h>
	36	#include <linux/string.h>
	37	#include <linux/kernel.h>
	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	/*
	59	* Setting the seed allows arbitrary accumulators and flexible XOR policy
	60	* If your algorithm starts with ~0, then XOR with ~0 before you set
	61	* the seed.
	62	*/
	63	static int crc32_setkey(struct crypto_shash hash, const u8 key,
	64	unsigned int keylen)
65	{
66	u32 *mctx = crypto_shash_ctx(hash);
67
68	if (keylen != sizeof(u32)) {
69	crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
70	return -EINVAL;
71	}
72	mctx = le32_to_cpup((__le32 )key);
73	return 0;
74	}
75
76	static int crc32_init(struct shash_desc *desc)
77	{
78	u32 *mctx = crypto_shash_ctx(desc->tfm);
79	u32 *crcp = shash_desc_ctx(desc);
80
81	crcp = mctx;
82
83	return 0;
84	}
85
86	static int crc32_update(struct shash_desc desc, const u8 data,
87	unsigned int len)
88	{
89	u32 *crcp = shash_desc_ctx(desc);
90
91	crcp = __crc32_le(crcp, data, len);
92	return 0;
93	}
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
143	static int __init crc32_mod_init(void)
144	{
145	return crypto_register_shash(&alg);
146	}
147
148	static void __exit crc32_mod_fini(void)
149	{
150	crypto_unregister_shash(&alg);
151	}
152
153	module_init(crc32_mod_init);
154	module_exit(crc32_mod_fini);
155
156	MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>");
157	MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32");
158	MODULE_LICENSE("GPL");
5d26a105	159	MODULE_ALIAS_CRYPTO("crc32");