1/* SPDX-License-Identifier: BSD-3-Clause */
2/* $OpenBSD: siphash.h,v 1.5 2015/02/20 11:51:03 tedu Exp $ */
3/*-
4 * Copyright (c) 2013 Andre Oppermann <andre@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote
16 * products derived from this software without specific prior written
17 * permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * $FreeBSD$
32 */
33
34/*
35 * SipHash is a family of pseudorandom functions (a.k.a. keyed hash functions)
36 * optimized for speed on short messages returning a 64bit hash/digest value.
37 *
38 * The number of rounds is defined during the initialization:
39 * SipHash24_Init() for the fast and resonable strong version
40 * SipHash48_Init() for the strong version (half as fast)
41 *
42 * struct SIPHASH_CTX ctx;
43 * SipHash24_Init(&ctx);
44 * SipHash_SetKey(&ctx, "16bytes long key");
45 * SipHash_Update(&ctx, pointer_to_string, length_of_string);
46 * SipHash_Final(output, &ctx);
47 */
48
49#ifndef _SIPHASH_H_
50#define _SIPHASH_H_
51
52#include <linux/types.h>
53
54#define SIPHASH_BLOCK_LENGTH 8
55#define SIPHASH_KEY_LENGTH 16
56#define SIPHASH_DIGEST_LENGTH 8
57
58typedef struct _SIPHASH_CTX {
59 u64 v[4];
60 u8 buf[SIPHASH_BLOCK_LENGTH];
61 u32 bytes;
62} SIPHASH_CTX;
63
64typedef struct {
65 __le64 k0;
66 __le64 k1;
67} SIPHASH_KEY;
68
69void SipHash_Init(SIPHASH_CTX *, const SIPHASH_KEY *);
70void SipHash_Update(SIPHASH_CTX *, int, int, const void *, size_t);
71u64 SipHash_End(SIPHASH_CTX *, int, int);
72void SipHash_Final(void *, SIPHASH_CTX *, int, int);
73u64 SipHash(const SIPHASH_KEY *, int, int, const void *, size_t);
74
75#define SipHash24_Init(_c, _k) SipHash_Init((_c), (_k))
76#define SipHash24_Update(_c, _p, _l) SipHash_Update((_c), 2, 4, (_p), (_l))
77#define SipHash24_End(_d) SipHash_End((_d), 2, 4)
78#define SipHash24_Final(_d, _c) SipHash_Final((_d), (_c), 2, 4)
79#define SipHash24(_k, _p, _l) SipHash((_k), 2, 4, (_p), (_l))
80
81#define SipHash48_Init(_c, _k) SipHash_Init((_c), (_k))
82#define SipHash48_Update(_c, _p, _l) SipHash_Update((_c), 4, 8, (_p), (_l))
83#define SipHash48_End(_d) SipHash_End((_d), 4, 8)
84#define SipHash48_Final(_d, _c) SipHash_Final((_d), (_c), 4, 8)
85#define SipHash48(_k, _p, _l) SipHash((_k), 4, 8, (_p), (_l))
86
87#endif /* _SIPHASH_H_ */
88

source code of linux/fs/bcachefs/siphash.h