1/* $OpenBSD: siphash.h,v 1.5 2015/02/20 11:51:03 tedu Exp $ */
2/*-
3 * Copyright (c) 2013 Andre Oppermann <andre@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote
15 *    products derived from this software without specific prior written
16 *    permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * $FreeBSD$
31 */
32
33/*
34 * SipHash is a family of pseudorandom functions (a.k.a. keyed hash functions)
35 * optimized for speed on short messages returning a 64bit hash/digest value.
36 *
37 * The number of rounds is defined during the initialization:
38 *  SipHash24_Init() for the fast and resonable strong version
39 *  SipHash48_Init() for the strong version (half as fast)
40 *
41 * struct SIPHASH_CTX ctx;
42 * SipHash24_Init(&ctx);
43 * SipHash_SetKey(&ctx, "16bytes long key");
44 * SipHash_Update(&ctx, pointer_to_string, length_of_string);
45 * SipHash_Final(output, &ctx);
46 */
47
48#ifndef _SIPHASH_H_
49#define _SIPHASH_H_
50
51#define SIPHASH_BLOCK_LENGTH	 8
52#define SIPHASH_KEY_LENGTH	16
53#define SIPHASH_DIGEST_LENGTH	 8
54
55typedef struct _SIPHASH_CTX {
56	uint64_t	v[4];
57	uint8_t	buf[SIPHASH_BLOCK_LENGTH];
58	uint32_t	bytes;
59} SIPHASH_CTX;
60
61typedef struct {
62	uint64_t	k0;
63	uint64_t	k1;
64} SIPHASH_KEY;
65
66void		SipHash_Init(SIPHASH_CTX *, const SIPHASH_KEY *);
67void		SipHash_Update(SIPHASH_CTX *, int, int, const void *, size_t)
68		    __bounded((__buffer__, 4, 5));
69uint64_t	SipHash_End(SIPHASH_CTX *, int, int);
70void		SipHash_Final(void *, SIPHASH_CTX *, int, int)
71		    __bounded((__minbytes__, 1, SIPHASH_DIGEST_LENGTH));
72uint64_t	SipHash(const SIPHASH_KEY *, int, int, const void *, size_t)
73		    __bounded((__buffer__, 4, 5));
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