[mirror_ubuntu-artful-kernel.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;

	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) {
			cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf,
				   GHASH_BLOCK_SIZE);
		}
	}

	n = srclen & ~(GHASH_BLOCK_SIZE - 1);
	if (n) {
		cpacf_kimd(CPACF_KIMD_GHASH, dctx, src, n);
		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;

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

		memset(pos, 0, dctx->bytes);
		cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf, GHASH_BLOCK_SIZE);
		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_func(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;
df1309ce GS	60	u8 *buf = dctx->buffer;
df1309ce GS	61
	62	if (dctx->bytes) {
	63	u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
	64
	65	n = min(srclen, dctx->bytes);
	66	dctx->bytes -= n;
	67	srclen -= n;
	68
	69	memcpy(pos, src, n);
	70	src += n;
	71
	72	if (!dctx->bytes) {
0177db01 MS	73	cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf,
0177db01 MS	74	GHASH_BLOCK_SIZE);
df1309ce GS	75	}
	76	}
	77
	78	n = srclen & ~(GHASH_BLOCK_SIZE - 1);
	79	if (n) {
0177db01	80	cpacf_kimd(CPACF_KIMD_GHASH, dctx, src, n);
df1309ce GS	81	src += n;
	82	srclen -= n;
	83	}
	84
	85	if (srclen) {
	86	dctx->bytes = GHASH_BLOCK_SIZE - srclen;
	87	memcpy(buf, src, srclen);
	88	}
	89
	90	return 0;
	91	}
	92
a1cae34e	93	static int ghash_flush(struct ghash_desc_ctx *dctx)
df1309ce GS	94	{
df1309ce GS	95	u8 *buf = dctx->buffer;
df1309ce GS	96
	97	if (dctx->bytes) {
	98	u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
	99
	100	memset(pos, 0, dctx->bytes);
0177db01	101	cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf, GHASH_BLOCK_SIZE);
a1cae34e	102	dctx->bytes = 0;
df1309ce GS	103	}
df1309ce GS	104
36eb2caa	105	return 0;
df1309ce GS	106	}
	107
	108	static int ghash_final(struct shash_desc desc, u8 dst)
	109	{
	110	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
36eb2caa	111	int ret;
df1309ce	112
a1cae34e	113	ret = ghash_flush(dctx);
36eb2caa	114	if (!ret)
a1cae34e	115	memcpy(dst, dctx->icv, GHASH_BLOCK_SIZE);
36eb2caa	116	return ret;
df1309ce GS	117	}
	118
	119	static struct shash_alg ghash_alg = {
	120	.digestsize = GHASH_DIGEST_SIZE,
	121	.init = ghash_init,
	122	.update = ghash_update,
	123	.final = ghash_final,
	124	.setkey = ghash_setkey,
	125	.descsize = sizeof(struct ghash_desc_ctx),
	126	.base = {
	127	.cra_name = "ghash",
	128	.cra_driver_name = "ghash-s390",
c7d4d259	129	.cra_priority = 300,
df1309ce GS	130	.cra_flags = CRYPTO_ALG_TYPE_SHASH,
	131	.cra_blocksize = GHASH_BLOCK_SIZE,
	132	.cra_ctxsize = sizeof(struct ghash_ctx),
	133	.cra_module = THIS_MODULE,
df1309ce GS	134	},
	135	};
	136
	137	static int __init ghash_mod_init(void)
	138	{
69c0e360	139	if (!cpacf_query_func(CPACF_KIMD, CPACF_KIMD_GHASH))
df1309ce GS	140	return -EOPNOTSUPP;
	141
	142	return crypto_register_shash(&ghash_alg);
	143	}
	144
	145	static void __exit ghash_mod_exit(void)
	146	{
	147	crypto_unregister_shash(&ghash_alg);
	148	}
	149
d05377c1	150	module_cpu_feature_match(MSA, ghash_mod_init);
df1309ce GS	151	module_exit(ghash_mod_exit);
df1309ce GS	152
5d26a105	153	MODULE_ALIAS_CRYPTO("ghash");
df1309ce GS	154
	155	MODULE_LICENSE("GPL");
	156	MODULE_DESCRIPTION("GHASH Message Digest Algorithm, s390 implementation");