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/zio_checksum.h>
  31 #include <sys/edonr.h>
  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 void
  49 abd_checksum_edonr_native(abd_t *abd, uint64_t size,
  50     const void *ctx_template, zio_cksum_t *zcp)
  51 {
  52         uint8_t         digest[EDONR_MODE / 8];
  53         EdonRState      ctx;
  54
  55         ASSERT(ctx_template != NULL);
  56         memcpy(&ctx, ctx_template, sizeof (ctx));
  57         (void) abd_iterate_func(abd, 0, size, edonr_incremental, &ctx);
  58         EdonRFinal(&ctx, digest);
  59         memcpy(zcp->zc_word, digest, sizeof (zcp->zc_word));
  60 }
  61
  62 /*
  63  * Byteswapped zio_checksum interface for the Edon-R hash function.
  64  */
  65 void
  66 abd_checksum_edonr_byteswap(abd_t *abd, uint64_t size,
  67     const void *ctx_template, zio_cksum_t *zcp)
  68 {
  69         zio_cksum_t     tmp;
  70
  71         abd_checksum_edonr_native(abd, size, ctx_template, &tmp);
  72         zcp->zc_word[0] = BSWAP_64(zcp->zc_word[0]);
  73         zcp->zc_word[1] = BSWAP_64(zcp->zc_word[1]);
  74         zcp->zc_word[2] = BSWAP_64(zcp->zc_word[2]);
  75         zcp->zc_word[3] = BSWAP_64(zcp->zc_word[3]);
  76 }
  77
  78 void *
  79 abd_checksum_edonr_tmpl_init(const zio_cksum_salt_t *salt)
  80 {
  81         EdonRState      *ctx;
  82         uint8_t         salt_block[EDONR_BLOCK_SIZE];
  83
  84         /*
  85          * Edon-R needs all but the last hash invocation to be on full-size
  86          * blocks, but the salt is too small. Rather than simply padding it
  87          * with zeros, we expand the salt into a new salt block of proper
  88          * size by double-hashing it (the new salt block will be composed of
  89          * H(salt) || H(H(salt))).
  90          */
  91         _Static_assert(EDONR_BLOCK_SIZE == 2 * (EDONR_MODE / 8),
  92             "Edon-R block size mismatch");
  93         EdonRHash(salt->zcs_bytes, sizeof (salt->zcs_bytes) * 8, salt_block);
  94         EdonRHash(salt_block, EDONR_MODE, salt_block + EDONR_MODE / 8);
  95
  96         /*
  97          * Feed the new salt block into the hash function - this will serve
  98          * as our MAC key.
  99          */
 100         ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
 101         EdonRInit(ctx);
 102         EdonRUpdate(ctx, salt_block, sizeof (salt_block) * 8);
 103         return (ctx);
 104 }
 105
 106 void
 107 abd_checksum_edonr_tmpl_free(void *ctx_template)
 108 {
 109         EdonRState *ctx = ctx_template;
 110
 111         memset(ctx, 0, sizeof (*ctx));
 112         kmem_free(ctx, sizeof (*ctx));
 113 }