[deliverable/linux.git] / arch / s390 / crypto / ghash_s390.c

/*
 * Cryptographic API.
 *
 * s390 implementation of the GHASH algorithm for GCM (Galois/Counter Mode).
 *
 * Copyright IBM Corp. 2011
 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
 */

#include <crypto/internal/hash.h>
#include <linux/module.h>
#include <linux/cpufeature.h>
#include <asm/cpacf.h>

#define GHASH_BLOCK_SIZE	16
#define GHASH_DIGEST_SIZE	16

struct ghash_ctx {
	u8 key[GHASH_BLOCK_SIZE];
};

struct ghash_desc_ctx {
	u8 icv[GHASH_BLOCK_SIZE];
	u8 key[GHASH_BLOCK_SIZE];
	u8 buffer[GHASH_BLOCK_SIZE];
	u32 bytes;
};

static int ghash_init(struct shash_desc *desc)
{
	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
	struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);

	memset(dctx, 0, sizeof(*dctx));
	memcpy(dctx->key, ctx->key, GHASH_BLOCK_SIZE);

	return 0;
}

static int ghash_setkey(struct crypto_shash *tfm,
			const u8 *key, unsigned int keylen)
{
	struct ghash_ctx *ctx = crypto_shash_ctx(tfm);

	if (keylen != GHASH_BLOCK_SIZE) {
		crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
		return -EINVAL;
	}

	memcpy(ctx->key, key, GHASH_BLOCK_SIZE);

	return 0;
}

static int ghash_update(struct shash_desc *desc,
			 const u8 *src, unsigned int srclen)
{
	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
	unsigned int n;
	u8 *buf = dctx->buffer;
	int ret;

	if (dctx->bytes) {
		u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);

		n = min(srclen, dctx->bytes);
		dctx->bytes -= n;
		srclen -= n;

		memcpy(pos, src, n);
		src += n;

		if (!dctx->bytes) {
			ret = cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf,
					 GHASH_BLOCK_SIZE);
			if (ret != GHASH_BLOCK_SIZE)
				return -EIO;
		}
	}

	n = srclen & ~(GHASH_BLOCK_SIZE - 1);
	if (n) {
		ret = cpacf_kimd(CPACF_KIMD_GHASH, dctx, src, n);
		if (ret != n)
			return -EIO;
		src += n;
		srclen -= n;
	}

	if (srclen) {
		dctx->bytes = GHASH_BLOCK_SIZE - srclen;
		memcpy(buf, src, srclen);
	}

	return 0;
}

static int ghash_flush(struct ghash_desc_ctx *dctx)
{
	u8 *buf = dctx->buffer;
	int ret;

	if (dctx->bytes) {
		u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);

		memset(pos, 0, dctx->bytes);

		ret = cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf, GHASH_BLOCK_SIZE);
		if (ret != GHASH_BLOCK_SIZE)
			return -EIO;

		dctx->bytes = 0;
	}

	return 0;
}

static int ghash_final(struct shash_desc *desc, u8 *dst)
{
	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
	int ret;

	ret = ghash_flush(dctx);
	if (!ret)
		memcpy(dst, dctx->icv, GHASH_BLOCK_SIZE);
	return ret;
}

static struct shash_alg ghash_alg = {
	.digestsize	= GHASH_DIGEST_SIZE,
	.init		= ghash_init,
	.update		= ghash_update,
	.final		= ghash_final,
	.setkey		= ghash_setkey,
	.descsize	= sizeof(struct ghash_desc_ctx),
	.base		= {
		.cra_name		= "ghash",
		.cra_driver_name	= "ghash-s390",
		.cra_priority		= 300,
		.cra_flags		= CRYPTO_ALG_TYPE_SHASH,
		.cra_blocksize		= GHASH_BLOCK_SIZE,
		.cra_ctxsize		= sizeof(struct ghash_ctx),
		.cra_module		= THIS_MODULE,
	},
};

static int __init ghash_mod_init(void)
{
	if (!cpacf_query(CPACF_KIMD, CPACF_KIMD_GHASH))
		return -EOPNOTSUPP;

	return crypto_register_shash(&ghash_alg);
}

static void __exit ghash_mod_exit(void)
{
	crypto_unregister_shash(&ghash_alg);
}

module_cpu_feature_match(MSA, ghash_mod_init);
module_exit(ghash_mod_exit);

MODULE_ALIAS_CRYPTO("ghash");

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("GHASH Message Digest Algorithm, s390 implementation");
Commit	Line	Data
df1309ce GS	1	/*
	2	* Cryptographic API.
	3	*
	4	* s390 implementation of the GHASH algorithm for GCM (Galois/Counter Mode).
	5	*
	6	* Copyright IBM Corp. 2011
	7	* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
	8	*/
	9
	10	#include <crypto/internal/hash.h>
	11	#include <linux/module.h>
d05377c1	12	#include <linux/cpufeature.h>
c7d4d259	13	#include <asm/cpacf.h>
df1309ce GS	14
	15	#define GHASH_BLOCK_SIZE 16
	16	#define GHASH_DIGEST_SIZE 16
	17
	18	struct ghash_ctx {
a1cae34e	19	u8 key[GHASH_BLOCK_SIZE];
df1309ce GS	20	};
	21
	22	struct ghash_desc_ctx {
a1cae34e HF	23	u8 icv[GHASH_BLOCK_SIZE];
a1cae34e HF	24	u8 key[GHASH_BLOCK_SIZE];
df1309ce GS	25	u8 buffer[GHASH_BLOCK_SIZE];
	26	u32 bytes;
	27	};
	28
	29	static int ghash_init(struct shash_desc *desc)
	30	{
	31	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
a1cae34e	32	struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
df1309ce GS	33
df1309ce GS	34	memset(dctx, 0, sizeof(*dctx));
a1cae34e	35	memcpy(dctx->key, ctx->key, GHASH_BLOCK_SIZE);
df1309ce GS	36
	37	return 0;
	38	}
	39
	40	static int ghash_setkey(struct crypto_shash *tfm,
	41	const u8 *key, unsigned int keylen)
	42	{
	43	struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
	44
	45	if (keylen != GHASH_BLOCK_SIZE) {
	46	crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
	47	return -EINVAL;
	48	}
	49
	50	memcpy(ctx->key, key, GHASH_BLOCK_SIZE);
df1309ce GS	51
	52	return 0;
	53	}
	54
	55	static int ghash_update(struct shash_desc *desc,
	56	const u8 *src, unsigned int srclen)
	57	{
	58	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
df1309ce GS	59	unsigned int n;
	60	u8 *buf = dctx->buffer;
	61	int ret;
	62
	63	if (dctx->bytes) {
	64	u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
	65
	66	n = min(srclen, dctx->bytes);
	67	dctx->bytes -= n;
	68	srclen -= n;
	69
	70	memcpy(pos, src, n);
	71	src += n;
	72
	73	if (!dctx->bytes) {
c7d4d259 MS	74	ret = cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf,
c7d4d259 MS	75	GHASH_BLOCK_SIZE);
36eb2caa JG	76	if (ret != GHASH_BLOCK_SIZE)
36eb2caa JG	77	return -EIO;
df1309ce GS	78	}
	79	}
	80
	81	n = srclen & ~(GHASH_BLOCK_SIZE - 1);
	82	if (n) {
c7d4d259	83	ret = cpacf_kimd(CPACF_KIMD_GHASH, dctx, src, n);
36eb2caa JG	84	if (ret != n)
36eb2caa JG	85	return -EIO;
df1309ce GS	86	src += n;
	87	srclen -= n;
	88	}
	89
	90	if (srclen) {
	91	dctx->bytes = GHASH_BLOCK_SIZE - srclen;
	92	memcpy(buf, src, srclen);
	93	}
	94
	95	return 0;
	96	}
	97
a1cae34e	98	static int ghash_flush(struct ghash_desc_ctx *dctx)
df1309ce GS	99	{
	100	u8 *buf = dctx->buffer;
	101	int ret;
	102
	103	if (dctx->bytes) {
	104	u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
	105
	106	memset(pos, 0, dctx->bytes);
	107
c7d4d259	108	ret = cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf, GHASH_BLOCK_SIZE);
36eb2caa JG	109	if (ret != GHASH_BLOCK_SIZE)
36eb2caa JG	110	return -EIO;
a1cae34e HF	111
a1cae34e HF	112	dctx->bytes = 0;
df1309ce GS	113	}
df1309ce GS	114
36eb2caa	115	return 0;
df1309ce GS	116	}
	117
	118	static int ghash_final(struct shash_desc desc, u8 dst)
	119	{
	120	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
36eb2caa	121	int ret;
df1309ce	122
a1cae34e	123	ret = ghash_flush(dctx);
36eb2caa	124	if (!ret)
a1cae34e	125	memcpy(dst, dctx->icv, GHASH_BLOCK_SIZE);
36eb2caa	126	return ret;
df1309ce GS	127	}
	128
	129	static struct shash_alg ghash_alg = {
	130	.digestsize = GHASH_DIGEST_SIZE,
	131	.init = ghash_init,
	132	.update = ghash_update,
	133	.final = ghash_final,
	134	.setkey = ghash_setkey,
	135	.descsize = sizeof(struct ghash_desc_ctx),
	136	.base = {
	137	.cra_name = "ghash",
	138	.cra_driver_name = "ghash-s390",
c7d4d259	139	.cra_priority = 300,
df1309ce GS	140	.cra_flags = CRYPTO_ALG_TYPE_SHASH,
	141	.cra_blocksize = GHASH_BLOCK_SIZE,
	142	.cra_ctxsize = sizeof(struct ghash_ctx),
	143	.cra_module = THIS_MODULE,
df1309ce GS	144	},
	145	};
	146
	147	static int __init ghash_mod_init(void)
	148	{
c7d4d259	149	if (!cpacf_query(CPACF_KIMD, CPACF_KIMD_GHASH))
df1309ce GS	150	return -EOPNOTSUPP;
	151
	152	return crypto_register_shash(&ghash_alg);
	153	}
	154
	155	static void __exit ghash_mod_exit(void)
	156	{
	157	crypto_unregister_shash(&ghash_alg);
	158	}
	159
d05377c1	160	module_cpu_feature_match(MSA, ghash_mod_init);
df1309ce GS	161	module_exit(ghash_mod_exit);
df1309ce GS	162
5d26a105	163	MODULE_ALIAS_CRYPTO("ghash");
df1309ce GS	164
	165	MODULE_LICENSE("GPL");
	166	MODULE_DESCRIPTION("GHASH Message Digest Algorithm, s390 implementation");