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      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