xref: /linux/fs/bcachefs/siphash.h (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
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 
58 typedef struct _SIPHASH_CTX {
59 	u64		v[4];
60 	u8		buf[SIPHASH_BLOCK_LENGTH];
61 	u32		bytes;
62 } SIPHASH_CTX;
63 
64 typedef struct {
65 	__le64		k0;
66 	__le64		k1;
67 } SIPHASH_KEY;
68 
69 void	SipHash_Init(SIPHASH_CTX *, const SIPHASH_KEY *);
70 void	SipHash_Update(SIPHASH_CTX *, int, int, const void *, size_t);
71 u64	SipHash_End(SIPHASH_CTX *, int, int);
72 void	SipHash_Final(void *, SIPHASH_CTX *, int, int);
73 u64	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