xref: /illumos-gate/usr/src/uts/common/fs/zfs/edonr_zfs.c (revision 9498083eeaed1aacdde41369b7fa6f3b84870791)
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*/
36 void
37 zio_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  */
53 void
54 zio_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 
66 void *
67 zio_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 
95 void
96 zio_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