[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 "crypt_s390.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 = crypt_s390_kimd(KIMD_GHASH, dctx, buf,
					      GHASH_BLOCK_SIZE);
			if (ret != GHASH_BLOCK_SIZE)
				return -EIO;
		}
	}

	n = srclen & ~(GHASH_BLOCK_SIZE - 1);
	if (n) {
		ret = crypt_s390_kimd(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 = crypt_s390_kimd(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		= CRYPT_S390_PRIORITY,
		.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 (!crypt_s390_func_available(KIMD_GHASH,
				       CRYPT_S390_MSA | CRYPT_S390_MSA4))
		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>
df1309ce GS	13
	14	#include "crypt_s390.h"
	15
	16	#define GHASH_BLOCK_SIZE 16
	17	#define GHASH_DIGEST_SIZE 16
	18
	19	struct ghash_ctx {
a1cae34e	20	u8 key[GHASH_BLOCK_SIZE];
df1309ce GS	21	};
	22
	23	struct ghash_desc_ctx {
a1cae34e HF	24	u8 icv[GHASH_BLOCK_SIZE];
a1cae34e HF	25	u8 key[GHASH_BLOCK_SIZE];
df1309ce GS	26	u8 buffer[GHASH_BLOCK_SIZE];
	27	u32 bytes;
	28	};
	29
	30	static int ghash_init(struct shash_desc *desc)
	31	{
	32	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
a1cae34e	33	struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
df1309ce GS	34
df1309ce GS	35	memset(dctx, 0, sizeof(*dctx));
a1cae34e	36	memcpy(dctx->key, ctx->key, GHASH_BLOCK_SIZE);
df1309ce GS	37
	38	return 0;
	39	}
	40
	41	static int ghash_setkey(struct crypto_shash *tfm,
	42	const u8 *key, unsigned int keylen)
	43	{
	44	struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
	45
	46	if (keylen != GHASH_BLOCK_SIZE) {
	47	crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
	48	return -EINVAL;
	49	}
	50
	51	memcpy(ctx->key, key, GHASH_BLOCK_SIZE);
df1309ce GS	52
	53	return 0;
	54	}
	55
	56	static int ghash_update(struct shash_desc *desc,
	57	const u8 *src, unsigned int srclen)
	58	{
	59	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
df1309ce GS	60	unsigned int n;
	61	u8 *buf = dctx->buffer;
	62	int ret;
	63
	64	if (dctx->bytes) {
	65	u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
	66
	67	n = min(srclen, dctx->bytes);
	68	dctx->bytes -= n;
	69	srclen -= n;
	70
	71	memcpy(pos, src, n);
	72	src += n;
	73
	74	if (!dctx->bytes) {
a1cae34e	75	ret = crypt_s390_kimd(KIMD_GHASH, dctx, buf,
df1309ce	76	GHASH_BLOCK_SIZE);
36eb2caa JG	77	if (ret != GHASH_BLOCK_SIZE)
36eb2caa JG	78	return -EIO;
df1309ce GS	79	}
	80	}
	81
	82	n = srclen & ~(GHASH_BLOCK_SIZE - 1);
	83	if (n) {
a1cae34e	84	ret = crypt_s390_kimd(KIMD_GHASH, dctx, src, n);
36eb2caa JG	85	if (ret != n)
36eb2caa JG	86	return -EIO;
df1309ce GS	87	src += n;
	88	srclen -= n;
	89	}
	90
	91	if (srclen) {
	92	dctx->bytes = GHASH_BLOCK_SIZE - srclen;
	93	memcpy(buf, src, srclen);
	94	}
	95
	96	return 0;
	97	}
	98
a1cae34e	99	static int ghash_flush(struct ghash_desc_ctx *dctx)
df1309ce GS	100	{
	101	u8 *buf = dctx->buffer;
	102	int ret;
	103
	104	if (dctx->bytes) {
	105	u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
	106
	107	memset(pos, 0, dctx->bytes);
	108
a1cae34e	109	ret = crypt_s390_kimd(KIMD_GHASH, dctx, buf, GHASH_BLOCK_SIZE);
36eb2caa JG	110	if (ret != GHASH_BLOCK_SIZE)
36eb2caa JG	111	return -EIO;
a1cae34e HF	112
a1cae34e HF	113	dctx->bytes = 0;
df1309ce GS	114	}
df1309ce GS	115
36eb2caa	116	return 0;
df1309ce GS	117	}
	118
	119	static int ghash_final(struct shash_desc desc, u8 dst)
	120	{
	121	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
36eb2caa	122	int ret;
df1309ce	123
a1cae34e	124	ret = ghash_flush(dctx);
36eb2caa	125	if (!ret)
a1cae34e	126	memcpy(dst, dctx->icv, GHASH_BLOCK_SIZE);
36eb2caa	127	return ret;
df1309ce GS	128	}
	129
	130	static struct shash_alg ghash_alg = {
	131	.digestsize = GHASH_DIGEST_SIZE,
	132	.init = ghash_init,
	133	.update = ghash_update,
	134	.final = ghash_final,
	135	.setkey = ghash_setkey,
	136	.descsize = sizeof(struct ghash_desc_ctx),
	137	.base = {
	138	.cra_name = "ghash",
	139	.cra_driver_name = "ghash-s390",
	140	.cra_priority = CRYPT_S390_PRIORITY,
	141	.cra_flags = CRYPTO_ALG_TYPE_SHASH,
	142	.cra_blocksize = GHASH_BLOCK_SIZE,
	143	.cra_ctxsize = sizeof(struct ghash_ctx),
	144	.cra_module = THIS_MODULE,
df1309ce GS	145	},
	146	};
	147
	148	static int __init ghash_mod_init(void)
	149	{
	150	if (!crypt_s390_func_available(KIMD_GHASH,
	151	CRYPT_S390_MSA \| CRYPT_S390_MSA4))
	152	return -EOPNOTSUPP;
	153
	154	return crypto_register_shash(&ghash_alg);
	155	}
	156
	157	static void __exit ghash_mod_exit(void)
	158	{
	159	crypto_unregister_shash(&ghash_alg);
	160	}
	161
d05377c1	162	module_cpu_feature_match(MSA, ghash_mod_init);
df1309ce GS	163	module_exit(ghash_mod_exit);
df1309ce GS	164
5d26a105	165	MODULE_ALIAS_CRYPTO("ghash");
df1309ce GS	166
	167	MODULE_LICENSE("GPL");
	168	MODULE_DESCRIPTION("GHASH Message Digest Algorithm, s390 implementation");