edonr_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 * Use is subject to license terms.
24 */
25#include <sys/zfs_context.h>
26#include <sys/zio.h>
27#include <sys/edonr.h>
28
29#define	EDONR_MODE		512
30#define	EDONR_BLOCK_SIZE	EdonR512_BLOCK_SIZE
31
32/*
33 * Native zio_checksum interface for the Edon-R hash function.
34 */
35/*ARGSUSED*/
36void
37zio_checksum_edonr_native(const void *buf, uint64_t size,
38    const void *ctx_template, zio_cksum_t *zcp)
39{
40	uint8_t		digest[EDONR_MODE / 8];
41	EdonRState	ctx;
42
43	ASSERT(ctx_template != NULL);
44	bcopy(ctx_template, &ctx, sizeof (ctx));
45	EdonRUpdate(&ctx, buf, size * 8);
46	EdonRFinal(&ctx, digest);
47	bcopy(digest, zcp->zc_word, sizeof (zcp->zc_word));
48}
49
50/*
51 * Byteswapped zio_checksum interface for the Edon-R hash function.
52 */
53void
54zio_checksum_edonr_byteswap(const void *buf, uint64_t size,
55    const void *ctx_template, zio_cksum_t *zcp)
56{
57	zio_cksum_t	tmp;
58
59	zio_checksum_edonr_native(buf, size, ctx_template, &tmp);
60	zcp->zc_word[0] = BSWAP_64(zcp->zc_word[0]);
61	zcp->zc_word[1] = BSWAP_64(zcp->zc_word[1]);
62	zcp->zc_word[2] = BSWAP_64(zcp->zc_word[2]);
63	zcp->zc_word[3] = BSWAP_64(zcp->zc_word[3]);
64}
65
66void *
67zio_checksum_edonr_tmpl_init(const zio_cksum_salt_t *salt)
68{
69	EdonRState	*ctx;
70	uint8_t		salt_block[EDONR_BLOCK_SIZE];
71
72	/*
73	 * Edon-R needs all but the last hash invocation to be on full-size
74	 * blocks, but the salt is too small. Rather than simply padding it
75	 * with zeros, we expand the salt into a new salt block of proper
76	 * size by double-hashing it (the new salt block will be composed of
77	 * H(salt) || H(H(salt))).
78	 */
79	CTASSERT(EDONR_BLOCK_SIZE == 2 * (EDONR_MODE / 8));
80	EdonRHash(EDONR_MODE, salt->zcs_bytes, sizeof (salt->zcs_bytes) * 8,
81	    salt_block);
82	EdonRHash(EDONR_MODE, salt_block, EDONR_MODE, salt_block +
83	    EDONR_MODE / 8);
84
85	/*
86	 * Feed the new salt block into the hash function - this will serve
87	 * as our MAC key.
88	 */
89	ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
90	EdonRInit(ctx, EDONR_MODE);
91	EdonRUpdate(ctx, salt_block, sizeof (salt_block) * 8);
92	return (ctx);
93}
94
95void
96zio_checksum_edonr_tmpl_free(void *ctx_template)
97{
98	EdonRState	*ctx = ctx_template;
99
100	bzero(ctx, sizeof (*ctx));
101	kmem_free(ctx, sizeof (*ctx));
102}
103