xref: /illumos-gate/usr/src/uts/common/fs/zfs/sha256.c (revision f76de749)
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://www.opensolaris.org/os/licensing.
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 2009 Sun Microsystems, Inc.  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/sha2.h>
28 
29 void
30 zio_checksum_SHA256(const void *buf, uint64_t size, zio_cksum_t *zcp)
31 {
32 	SHA2_CTX ctx;
33 	zio_cksum_t tmp;
34 
35 	SHA2Init(SHA256, &ctx);
36 	SHA2Update(&ctx, buf, size);
37 	SHA2Final(&tmp, &ctx);
38 
39 	/*
40 	 * A prior implementation of this function had a
41 	 * private SHA256 implementation always wrote things out in
42 	 * Big Endian and there wasn't a byteswap variant of it.
43 	 * To preseve on disk compatibility we need to force that
44 	 * behaviour.
45 	 */
46 	zcp->zc_word[0] = BE_64(tmp.zc_word[0]);
47 	zcp->zc_word[1] = BE_64(tmp.zc_word[1]);
48 	zcp->zc_word[2] = BE_64(tmp.zc_word[2]);
49 	zcp->zc_word[3] = BE_64(tmp.zc_word[3]);
50 }
51