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 #ifdef _KERNEL
27 #include <crypto/skein/skein.h>
28 #else
29 #include <skein.h>
30 #endif
31
32 /*
33 * Computes a native 256-bit skein MAC checksum. Please note that this
34 * function requires the presence of a ctx_template that should be allocated
35 * using zio_checksum_skein_tmpl_init.
36 */
37 /*ARGSUSED*/
38 void
zio_checksum_skein_native(const void * buf,uint64_t size,const void * ctx_template,zio_cksum_t * zcp)39 zio_checksum_skein_native(const void *buf, uint64_t size,
40 const void *ctx_template, zio_cksum_t *zcp)
41 {
42 Skein_512_Ctxt_t ctx;
43
44 ASSERT(ctx_template != NULL);
45 bcopy(ctx_template, &ctx, sizeof (ctx));
46 (void) Skein_512_Update(&ctx, buf, size);
47 (void) Skein_512_Final(&ctx, (uint8_t *)zcp);
48 bzero(&ctx, sizeof (ctx));
49 }
50
51 /*
52 * Byteswapped version of zio_checksum_skein_native. This just invokes
53 * the native checksum function and byteswaps the resulting checksum (since
54 * skein is internally endian-insensitive).
55 */
56 void
zio_checksum_skein_byteswap(const void * buf,uint64_t size,const void * ctx_template,zio_cksum_t * zcp)57 zio_checksum_skein_byteswap(const void *buf, uint64_t size,
58 const void *ctx_template, zio_cksum_t *zcp)
59 {
60 zio_cksum_t tmp;
61
62 zio_checksum_skein_native(buf, size, ctx_template, &tmp);
63 zcp->zc_word[0] = BSWAP_64(tmp.zc_word[0]);
64 zcp->zc_word[1] = BSWAP_64(tmp.zc_word[1]);
65 zcp->zc_word[2] = BSWAP_64(tmp.zc_word[2]);
66 zcp->zc_word[3] = BSWAP_64(tmp.zc_word[3]);
67 }
68
69 /*
70 * Allocates a skein MAC template suitable for using in skein MAC checksum
71 * computations and returns a pointer to it.
72 */
73 void *
zio_checksum_skein_tmpl_init(const zio_cksum_salt_t * salt)74 zio_checksum_skein_tmpl_init(const zio_cksum_salt_t *salt)
75 {
76 Skein_512_Ctxt_t *ctx;
77
78 ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
79 (void) Skein_512_InitExt(ctx, sizeof (zio_cksum_t) * 8, 0,
80 salt->zcs_bytes, sizeof (salt->zcs_bytes));
81 return (ctx);
82 }
83
84 /*
85 * Frees a skein context template previously allocated using
86 * zio_checksum_skein_tmpl_init.
87 */
88 void
zio_checksum_skein_tmpl_free(void * ctx_template)89 zio_checksum_skein_tmpl_free(void *ctx_template)
90 {
91 Skein_512_Ctxt_t *ctx = ctx_template;
92
93 bzero(ctx, sizeof (*ctx));
94 kmem_free(ctx, sizeof (*ctx));
95 }
96