usr/src/uts/common/fs/zfs/skein_zfs.c

   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*/
  34 void
  35 zio_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  */
  52 void
  53 zio_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  */
  69 void *
  70 zio_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  */
  84 void
  85 zio_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 }