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/skein.h>
25
26/*
27 * Computes a native 256-bit skein MAC checksum. Please note that this
28 * function requires the presence of a ctx_template that should be allocated
29 * using zio_checksum_skein_tmpl_init.
30 */
31/*ARGSUSED*/
32static void
33zio_checksum_skein_native(const void *buf, uint64_t size,
34    const void *ctx_template, zio_cksum_t *zcp)
35{
36	Skein_512_Ctxt_t	ctx;
37
38	ASSERT(ctx_template != NULL);
39	bcopy(ctx_template, &ctx, sizeof (ctx));
40	(void) Skein_512_Update(&ctx, buf, size);
41	(void) Skein_512_Final(&ctx, (uint8_t *)zcp);
42	bzero(&ctx, sizeof (ctx));
43}
44
45/*
46 * Byteswapped version of zio_checksum_skein_native. This just invokes
47 * the native checksum function and byteswaps the resulting checksum (since
48 * skein is internally endian-insensitive).
49 */
50static void
51zio_checksum_skein_byteswap(const void *buf, uint64_t size,
52    const void *ctx_template, zio_cksum_t *zcp)
53{
54	zio_cksum_t	tmp;
55
56	zio_checksum_skein_native(buf, size, ctx_template, &tmp);
57	zcp->zc_word[0] = BSWAP_64(tmp.zc_word[0]);
58	zcp->zc_word[1] = BSWAP_64(tmp.zc_word[1]);
59	zcp->zc_word[2] = BSWAP_64(tmp.zc_word[2]);
60	zcp->zc_word[3] = BSWAP_64(tmp.zc_word[3]);
61}
62
63/*
64 * Allocates a skein MAC template suitable for using in skein MAC checksum
65 * computations and returns a pointer to it.
66 */
67static void *
68zio_checksum_skein_tmpl_init(const zio_cksum_salt_t *salt)
69{
70	Skein_512_Ctxt_t	*ctx;
71
72	ctx = malloc(sizeof (*ctx));
73	bzero(ctx, sizeof (*ctx));
74	(void) Skein_512_InitExt(ctx, sizeof (zio_cksum_t) * 8, 0,
75	    salt->zcs_bytes, sizeof (salt->zcs_bytes));
76	return (ctx);
77}
78
79/*
80 * Frees a skein context template previously allocated using
81 * zio_checksum_skein_tmpl_init.
82 */
83static void
84zio_checksum_skein_tmpl_free(void *ctx_template)
85{
86	Skein_512_Ctxt_t	*ctx = ctx_template;
87
88	bzero(ctx, sizeof (*ctx));
89	free(ctx);
90}
91