skein_zfs.c revision 290757 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://opensource.org/licenses/CDDL-1.0.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2013 Saso Kiselkov.  All rights reserved.
23 */
24#include <sys/zfs_context.h>
25#include <sys/zio.h>
26#include <sys/skein.h>
27
28/*
29 * Computes a native 256-bit skein MAC checksum. Please note that this
30 * function requires the presence of a ctx_template that should be allocated
31 * using zio_checksum_skein_tmpl_init.
32 */
33/*ARGSUSED*/
34void
35zio_checksum_skein_native(const void *buf, uint64_t size,
36    const void *ctx_template, zio_cksum_t *zcp)
37{
38	Skein_512_Ctxt_t	ctx;
39
40	ASSERT(ctx_template != NULL);
41	bcopy(ctx_template, &ctx, sizeof (ctx));
42	(void) Skein_512_Update(&ctx, buf, size);
43	(void) Skein_512_Final(&ctx, (uint8_t *)zcp);
44	bzero(&ctx, sizeof (ctx));
45}
46
47/*
48 * Byteswapped version of zio_checksum_skein_native. This just invokes
49 * the native checksum function and byteswaps the resulting checksum (since
50 * skein is internally endian-insensitive).
51 */
52void
53zio_checksum_skein_byteswap(const void *buf, uint64_t size,
54    const void *ctx_template, zio_cksum_t *zcp)
55{
56	zio_cksum_t	tmp;
57
58	zio_checksum_skein_native(buf, size, ctx_template, &tmp);
59	zcp->zc_word[0] = BSWAP_64(tmp.zc_word[0]);
60	zcp->zc_word[1] = BSWAP_64(tmp.zc_word[1]);
61	zcp->zc_word[2] = BSWAP_64(tmp.zc_word[2]);
62	zcp->zc_word[3] = BSWAP_64(tmp.zc_word[3]);
63}
64
65/*
66 * Allocates a skein MAC template suitable for using in skein MAC checksum
67 * computations and returns a pointer to it.
68 */
69void *
70zio_checksum_skein_tmpl_init(const zio_cksum_salt_t *salt)
71{
72	Skein_512_Ctxt_t	*ctx;
73
74	ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
75	(void) Skein_512_InitExt(ctx, sizeof (zio_cksum_t) * 8, 0,
76	    salt->zcs_bytes, sizeof (salt->zcs_bytes));
77	return (ctx);
78}
79
80/*
81 * Frees a skein context template previously allocated using
82 * zio_checksum_skein_tmpl_init.
83 */
84void
85zio_checksum_skein_tmpl_free(void *ctx_template)
86{
87	Skein_512_Ctxt_t	*ctx = ctx_template;
88
89	bzero(ctx, sizeof (*ctx));
90	kmem_free(ctx, sizeof (*ctx));
91}
92