module/zfs/edonr_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  * Use is subject to license terms.
  24  */
  25 /*
  26  * Copyright (c) 2016 by Delphix. All rights reserved.
  27  */
  28 #include <sys/zfs_context.h>
  29 #include <sys/zio.h>
  30 #include <sys/edonr.h>
  31 #include <sys/zfs_context.h>    /* For CTASSERT() */
  32 #include <sys/abd.h>
  33
  34 #define EDONR_MODE              512
  35 #define EDONR_BLOCK_SIZE        EdonR512_BLOCK_SIZE
  36
  37 static int
  38 edonr_incremental(void *buf, size_t size, void *arg)
  39 {
  40         EdonRState *ctx = arg;
  41         EdonRUpdate(ctx, buf, size * 8);
  42         return (0);
  43 }
  44
  45 /*
  46  * Native zio_checksum interface for the Edon-R hash function.
  47  */
  48 /*ARGSUSED*/
  49 void
  50 abd_checksum_edonr_native(abd_t *abd, uint64_t size,
  51     const void *ctx_template, zio_cksum_t *zcp)
  52 {
  53         uint8_t         digest[EDONR_MODE / 8];
  54         EdonRState      ctx;
  55
  56         ASSERT(ctx_template != NULL);
  57         bcopy(ctx_template, &ctx, sizeof (ctx));
  58         (void) abd_iterate_func(abd, 0, size, edonr_incremental, &ctx);
  59         EdonRFinal(&ctx, digest);
  60         bcopy(digest, zcp->zc_word, sizeof (zcp->zc_word));
  61 }
  62
  63 /*
  64  * Byteswapped zio_checksum interface for the Edon-R hash function.
  65  */
  66 void
  67 abd_checksum_edonr_byteswap(abd_t *abd, uint64_t size,
  68     const void *ctx_template, zio_cksum_t *zcp)
  69 {
  70         zio_cksum_t     tmp;
  71
  72         abd_checksum_edonr_native(abd, size, ctx_template, &tmp);
  73         zcp->zc_word[0] = BSWAP_64(zcp->zc_word[0]);
  74         zcp->zc_word[1] = BSWAP_64(zcp->zc_word[1]);
  75         zcp->zc_word[2] = BSWAP_64(zcp->zc_word[2]);
  76         zcp->zc_word[3] = BSWAP_64(zcp->zc_word[3]);
  77 }
  78
  79 void *
  80 abd_checksum_edonr_tmpl_init(const zio_cksum_salt_t *salt)
  81 {
  82         EdonRState      *ctx;
  83         uint8_t         salt_block[EDONR_BLOCK_SIZE];
  84
  85         /*
  86          * Edon-R needs all but the last hash invocation to be on full-size
  87          * blocks, but the salt is too small. Rather than simply padding it
  88          * with zeros, we expand the salt into a new salt block of proper
  89          * size by double-hashing it (the new salt block will be composed of
  90          * H(salt) || H(H(salt))).
  91          */
  92         CTASSERT(EDONR_BLOCK_SIZE == 2 * (EDONR_MODE / 8));
  93         EdonRHash(EDONR_MODE, salt->zcs_bytes, sizeof (salt->zcs_bytes) * 8,
  94             salt_block);
  95         EdonRHash(EDONR_MODE, salt_block, EDONR_MODE, salt_block +
  96             EDONR_MODE / 8);
  97
  98         /*
  99          * Feed the new salt block into the hash function - this will serve
 100          * as our MAC key.
 101          */
 102         ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
 103         EdonRInit(ctx, EDONR_MODE);
 104         EdonRUpdate(ctx, salt_block, sizeof (salt_block) * 8);
 105         return (ctx);
 106 }
 107
 108 void
 109 abd_checksum_edonr_tmpl_free(void *ctx_template)
 110 {
 111         EdonRState      *ctx = ctx_template;
 112
 113         bzero(ctx, sizeof (*ctx));
 114         kmem_free(ctx, sizeof (*ctx));
 115 }