[linux-2.6-block.git] / arch / s390 / crypto / ghash_s390.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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
20a884f5	1	// SPDX-License-Identifier: GPL-2.0
df1309ce GS	2	/*
	3	* Cryptographic API.
	4	*
	5	* s390 implementation of the GHASH algorithm for GCM (Galois/Counter Mode).
	6	*
	7	* Copyright IBM Corp. 2011
	8	* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
	9	*/
	10
	11	#include <crypto/internal/hash.h>
	12	#include <linux/module.h>
d05377c1	13	#include <linux/cpufeature.h>
c7d4d259	14	#include <asm/cpacf.h>
df1309ce GS	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;
df1309ce GS	61	u8 *buf = dctx->buffer;
df1309ce GS	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) {
0177db01 MS	74	cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf,
0177db01 MS	75	GHASH_BLOCK_SIZE);
df1309ce GS	76	}
	77	}
	78
	79	n = srclen & ~(GHASH_BLOCK_SIZE - 1);
	80	if (n) {
0177db01	81	cpacf_kimd(CPACF_KIMD_GHASH, dctx, src, n);
df1309ce GS	82	src += n;
	83	srclen -= n;
	84	}
	85
	86	if (srclen) {
	87	dctx->bytes = GHASH_BLOCK_SIZE - srclen;
	88	memcpy(buf, src, srclen);
	89	}
	90
	91	return 0;
	92	}
	93
a1cae34e	94	static int ghash_flush(struct ghash_desc_ctx *dctx)
df1309ce GS	95	{
df1309ce GS	96	u8 *buf = dctx->buffer;
df1309ce GS	97
	98	if (dctx->bytes) {
	99	u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
	100
	101	memset(pos, 0, dctx->bytes);
0177db01	102	cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf, GHASH_BLOCK_SIZE);
a1cae34e	103	dctx->bytes = 0;
df1309ce GS	104	}
df1309ce GS	105
36eb2caa	106	return 0;
df1309ce GS	107	}
	108
	109	static int ghash_final(struct shash_desc desc, u8 dst)
	110	{
	111	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
36eb2caa	112	int ret;
df1309ce	113
a1cae34e	114	ret = ghash_flush(dctx);
36eb2caa	115	if (!ret)
a1cae34e	116	memcpy(dst, dctx->icv, GHASH_BLOCK_SIZE);
36eb2caa	117	return ret;
df1309ce GS	118	}
	119
	120	static struct shash_alg ghash_alg = {
	121	.digestsize = GHASH_DIGEST_SIZE,
	122	.init = ghash_init,
	123	.update = ghash_update,
	124	.final = ghash_final,
	125	.setkey = ghash_setkey,
	126	.descsize = sizeof(struct ghash_desc_ctx),
	127	.base = {
	128	.cra_name = "ghash",
	129	.cra_driver_name = "ghash-s390",
c7d4d259	130	.cra_priority = 300,
df1309ce GS	131	.cra_flags = CRYPTO_ALG_TYPE_SHASH,
	132	.cra_blocksize = GHASH_BLOCK_SIZE,
	133	.cra_ctxsize = sizeof(struct ghash_ctx),
	134	.cra_module = THIS_MODULE,
df1309ce GS	135	},
	136	};
	137
	138	static int __init ghash_mod_init(void)
	139	{
69c0e360	140	if (!cpacf_query_func(CPACF_KIMD, CPACF_KIMD_GHASH))
df1309ce GS	141	return -EOPNOTSUPP;
	142
	143	return crypto_register_shash(&ghash_alg);
	144	}
	145
	146	static void __exit ghash_mod_exit(void)
	147	{
	148	crypto_unregister_shash(&ghash_alg);
	149	}
	150
d05377c1	151	module_cpu_feature_match(MSA, ghash_mod_init);
df1309ce GS	152	module_exit(ghash_mod_exit);
df1309ce GS	153
5d26a105	154	MODULE_ALIAS_CRYPTO("ghash");
df1309ce GS	155
	156	MODULE_LICENSE("GPL");
	157	MODULE_DESCRIPTION("GHASH Message Digest Algorithm, s390 implementation");