[thirdparty/kernel/stable.git] / crypto / ghash-generic.c

/*
 * GHASH: digest algorithm for GCM (Galois/Counter Mode).
 *
 * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
 * Copyright (c) 2009 Intel Corp.
 *   Author: Huang Ying <ying.huang@intel.com>
 *
 * The algorithm implementation is copied from gcm.c.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 */

#include <crypto/algapi.h>
#include <crypto/gf128mul.h>
#include <crypto/ghash.h>
#include <crypto/internal/hash.h>
#include <linux/crypto.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>

static int ghash_init(struct shash_desc *desc)
{
	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);

	memset(dctx, 0, sizeof(*dctx));

	return 0;
}

static int ghash_setkey(struct crypto_shash *tfm,
			const u8 *key, unsigned int keylen)
{
	struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
	be128 k;

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

	if (ctx->gf128)
		gf128mul_free_4k(ctx->gf128);

	BUILD_BUG_ON(sizeof(k) != GHASH_BLOCK_SIZE);
	memcpy(&k, key, GHASH_BLOCK_SIZE); /* avoid violating alignment rules */
	ctx->gf128 = gf128mul_init_4k_lle(&k);
	memzero_explicit(&k, GHASH_BLOCK_SIZE);

	if (!ctx->gf128)
		return -ENOMEM;

	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);
	struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
	u8 *dst = dctx->buffer;

	if (dctx->bytes) {
		int n = min(srclen, dctx->bytes);
		u8 *pos = dst + (GHASH_BLOCK_SIZE - dctx->bytes);

		dctx->bytes -= n;
		srclen -= n;

		while (n--)
			*pos++ ^= *src++;

		if (!dctx->bytes)
			gf128mul_4k_lle((be128 *)dst, ctx->gf128);
	}

	while (srclen >= GHASH_BLOCK_SIZE) {
		crypto_xor(dst, src, GHASH_BLOCK_SIZE);
		gf128mul_4k_lle((be128 *)dst, ctx->gf128);
		src += GHASH_BLOCK_SIZE;
		srclen -= GHASH_BLOCK_SIZE;
	}

	if (srclen) {
		dctx->bytes = GHASH_BLOCK_SIZE - srclen;
		while (srclen--)
			*dst++ ^= *src++;
	}

	return 0;
}

static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
{
	u8 *dst = dctx->buffer;

	if (dctx->bytes) {
		u8 *tmp = dst + (GHASH_BLOCK_SIZE - dctx->bytes);

		while (dctx->bytes--)
			*tmp++ ^= 0;

		gf128mul_4k_lle((be128 *)dst, ctx->gf128);
	}

	dctx->bytes = 0;
}

static int ghash_final(struct shash_desc *desc, u8 *dst)
{
	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
	struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
	u8 *buf = dctx->buffer;

	ghash_flush(ctx, dctx);
	memcpy(dst, buf, GHASH_BLOCK_SIZE);

	return 0;
}

static void ghash_exit_tfm(struct crypto_tfm *tfm)
{
	struct ghash_ctx *ctx = crypto_tfm_ctx(tfm);
	if (ctx->gf128)
		gf128mul_free_4k(ctx->gf128);
}

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-generic",
		.cra_priority		= 100,
		.cra_blocksize		= GHASH_BLOCK_SIZE,
		.cra_ctxsize		= sizeof(struct ghash_ctx),
		.cra_module		= THIS_MODULE,
		.cra_exit		= ghash_exit_tfm,
	},
};

static int __init ghash_mod_init(void)
{
	return crypto_register_shash(&ghash_alg);
}

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

module_init(ghash_mod_init);
module_exit(ghash_mod_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("GHASH Message Digest Algorithm");
MODULE_ALIAS_CRYPTO("ghash");
MODULE_ALIAS_CRYPTO("ghash-generic");
Commit	Line	Data
2cdc6899 HY	1	/*
	2	* GHASH: digest algorithm for GCM (Galois/Counter Mode).
	3	*
	4	* Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
	5	* Copyright (c) 2009 Intel Corp.
	6	* Author: Huang Ying <ying.huang@intel.com>
	7	*
	8	* The algorithm implementation is copied from gcm.c.
	9	*
	10	* This program is free software; you can redistribute it and/or modify it
	11	* under the terms of the GNU General Public License version 2 as published
	12	* by the Free Software Foundation.
	13	*/
	14
	15	#include <crypto/algapi.h>
	16	#include <crypto/gf128mul.h>
a397ba82	17	#include <crypto/ghash.h>
2cdc6899 HY	18	#include <crypto/internal/hash.h>
	19	#include <linux/crypto.h>
	20	#include <linux/init.h>
	21	#include <linux/kernel.h>
	22	#include <linux/module.h>
	23
2cdc6899 HY	24	static int ghash_init(struct shash_desc *desc)
	25	{
	26	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
	27
	28	memset(dctx, 0, sizeof(*dctx));
	29
	30	return 0;
	31	}
	32
	33	static int ghash_setkey(struct crypto_shash *tfm,
	34	const u8 *key, unsigned int keylen)
	35	{
	36	struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
f80432bf	37	be128 k;
2cdc6899 HY	38
	39	if (keylen != GHASH_BLOCK_SIZE) {
	40	crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
	41	return -EINVAL;
	42	}
	43
	44	if (ctx->gf128)
	45	gf128mul_free_4k(ctx->gf128);
f80432bf EB	46
	47	BUILD_BUG_ON(sizeof(k) != GHASH_BLOCK_SIZE);
	48	memcpy(&k, key, GHASH_BLOCK_SIZE); /* avoid violating alignment rules */
	49	ctx->gf128 = gf128mul_init_4k_lle(&k);
	50	memzero_explicit(&k, GHASH_BLOCK_SIZE);
	51
2cdc6899 HY	52	if (!ctx->gf128)
	53	return -ENOMEM;
	54
	55	return 0;
	56	}
	57
	58	static int ghash_update(struct shash_desc *desc,
	59	const u8 *src, unsigned int srclen)
	60	{
	61	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
	62	struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
	63	u8 *dst = dctx->buffer;
	64
	65	if (dctx->bytes) {
	66	int n = min(srclen, dctx->bytes);
	67	u8 *pos = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
	68
	69	dctx->bytes -= n;
	70	srclen -= n;
	71
	72	while (n--)
	73	pos++ ^= src++;
	74
	75	if (!dctx->bytes)
	76	gf128mul_4k_lle((be128 *)dst, ctx->gf128);
	77	}
	78
	79	while (srclen >= GHASH_BLOCK_SIZE) {
	80	crypto_xor(dst, src, GHASH_BLOCK_SIZE);
	81	gf128mul_4k_lle((be128 *)dst, ctx->gf128);
	82	src += GHASH_BLOCK_SIZE;
	83	srclen -= GHASH_BLOCK_SIZE;
	84	}
	85
	86	if (srclen) {
	87	dctx->bytes = GHASH_BLOCK_SIZE - srclen;
	88	while (srclen--)
	89	dst++ ^= src++;
	90	}
	91
	92	return 0;
	93	}
	94
	95	static void ghash_flush(struct ghash_ctx ctx, struct ghash_desc_ctx dctx)
	96	{
	97	u8 *dst = dctx->buffer;
	98
	99	if (dctx->bytes) {
	100	u8 *tmp = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
	101
	102	while (dctx->bytes--)
	103	*tmp++ ^= 0;
	104
	105	gf128mul_4k_lle((be128 *)dst, ctx->gf128);
	106	}
	107
	108	dctx->bytes = 0;
	109	}
	110
	111	static int ghash_final(struct shash_desc desc, u8 dst)
	112	{
	113	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
	114	struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
	115	u8 *buf = dctx->buffer;
116
117	ghash_flush(ctx, dctx);
118	memcpy(dst, buf, GHASH_BLOCK_SIZE);
119
120	return 0;
121	}
122
123	static void ghash_exit_tfm(struct crypto_tfm *tfm)
124	{
125	struct ghash_ctx *ctx = crypto_tfm_ctx(tfm);
126	if (ctx->gf128)
127	gf128mul_free_4k(ctx->gf128);
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-generic",
140	.cra_priority = 100,
2cdc6899 HY	141	.cra_blocksize = GHASH_BLOCK_SIZE,
	142	.cra_ctxsize = sizeof(struct ghash_ctx),
	143	.cra_module = THIS_MODULE,
2cdc6899 HY	144	.cra_exit = ghash_exit_tfm,
	145	},
	146	};
	147
	148	static int __init ghash_mod_init(void)
	149	{
	150	return crypto_register_shash(&ghash_alg);
	151	}
	152
	153	static void __exit ghash_mod_exit(void)
	154	{
	155	crypto_unregister_shash(&ghash_alg);
	156	}
	157
	158	module_init(ghash_mod_init);
	159	module_exit(ghash_mod_exit);
	160
	161	MODULE_LICENSE("GPL");
	162	MODULE_DESCRIPTION("GHASH Message Digest Algorithm");
5d26a105	163	MODULE_ALIAS_CRYPTO("ghash");
3e14dcf7	164	MODULE_ALIAS_CRYPTO("ghash-generic");