xref: /freebsd/sys/cddl/boot/zfs/blake3_zfs.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
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 /*
23  * Copyright 2022 Tino Reichardt <milky-zfs@mcmilk.de>
24  */
25 
26 #include <sys/blake3.h>
27 
28 /*
29  * Computes a native 256-bit BLAKE3 MAC checksum. Please note that this
30  * function requires the presence of a ctx_template that should be allocated
31  * using zio_checksum_blake3_tmpl_init.
32  */
33 static void
34 zio_checksum_blake3_native(const void *buf, uint64_t size,
35     const void *ctx_template, zio_cksum_t *zcp)
36 {
37 	BLAKE3_CTX ctx;
38 
39 	ASSERT(ctx_template != 0);
40 
41 	memcpy(&ctx, ctx_template, sizeof(ctx));
42 	Blake3_Update(&ctx, buf, size);
43 	Blake3_Final(&ctx, (uint8_t *)zcp);
44 
45 	memset(&ctx, 0, sizeof (ctx));
46 }
47 
48 /*
49  * Byteswapped version of zio_checksum_blake3_native. This just invokes
50  * the native checksum function and byteswaps the resulting checksum (since
51  * BLAKE3 is internally endian-insensitive).
52  */
53 static void
54 zio_checksum_blake3_byteswap(const void *buf, uint64_t size,
55     const void *ctx_template, zio_cksum_t *zcp)
56 {
57 	zio_cksum_t tmp;
58 
59 	ASSERT(ctx_template != 0);
60 
61 	zio_checksum_blake3_native(buf, size, ctx_template, &tmp);
62 	zcp->zc_word[0] = BSWAP_64(tmp.zc_word[0]);
63 	zcp->zc_word[1] = BSWAP_64(tmp.zc_word[1]);
64 	zcp->zc_word[2] = BSWAP_64(tmp.zc_word[2]);
65 	zcp->zc_word[3] = BSWAP_64(tmp.zc_word[3]);
66 }
67 
68 /*
69  * Allocates a BLAKE3 MAC template suitable for using in BLAKE3 MAC checksum
70  * computations and returns a pointer to it.
71  */
72 static void *
73 zio_checksum_blake3_tmpl_init(const zio_cksum_salt_t *salt)
74 {
75 	BLAKE3_CTX *ctx;
76 
77 	ASSERT(sizeof (salt->zcs_bytes) == 32);
78 
79 	/* init reference object */
80 	ctx = calloc(1, sizeof(*ctx));
81 	Blake3_InitKeyed(ctx, salt->zcs_bytes);
82 
83 	return (ctx);
84 }
85 
86 /*
87  * Frees a BLAKE3 context template previously allocated using
88  * zio_checksum_blake3_tmpl_init.
89  */
90 static void
91 zio_checksum_blake3_tmpl_free(void *ctx_template)
92 {
93 	BLAKE3_CTX *ctx = ctx_template;
94 
95 	memset(ctx, 0, sizeof(*ctx));
96 	free(ctx);
97 }
98