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 */
33static void
34zio_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 */
53static void
54zio_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 */
72static void *
73zio_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 */
90static void
91zio_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