summaryrefslogtreecommitdiff
path: root/include/linux/siphash.h
blob: 3f7427b9e9357d98b1e21a981cf227195bbdd2aa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
/* Copyright (C) 2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
 *
 * This file is provided under a dual BSD/GPLv2 license.
 *
 * SipHash: a fast short-input PRF
 * https://131002.net/siphash/
 *
 * This implementation is specifically for SipHash2-4 for a secure PRF
 * and HalfSipHash1-3/SipHash1-3 for an insecure PRF only suitable for
 * hashtables.
 */

#ifndef _LINUX_SIPHASH_H
#define _LINUX_SIPHASH_H

#include <linux/types.h>
#include <linux/kernel.h>

#define SIPHASH_ALIGNMENT __alignof__(u64)
typedef struct {
	u64 key[2];
} siphash_key_t;

#define siphash_aligned_key_t siphash_key_t __aligned(16)

static inline bool siphash_key_is_zero(const siphash_key_t *key)
{
	return !(key->key[0] | key->key[1]);
}

u64 __siphash_aligned(const void *data, size_t len, const siphash_key_t *key);
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
u64 __siphash_unaligned(const void *data, size_t len, const siphash_key_t *key);
#endif

u64 siphash_1u64(const u64 a, const siphash_key_t *key);
u64 siphash_2u64(const u64 a, const u64 b, const siphash_key_t *key);
u64 siphash_3u64(const u64 a, const u64 b, const u64 c,
		 const siphash_key_t *key);
u64 siphash_4u64(const u64 a, const u64 b, const u64 c, const u64 d,
		 const siphash_key_t *key);
u64 siphash_1u32(const u32 a, const siphash_key_t *key);
u64 siphash_3u32(const u32 a, const u32 b, const u32 c,
		 const siphash_key_t *key);

static inline u64 siphash_2u32(const u32 a, const u32 b,
			       const siphash_key_t *key)
{
	return siphash_1u64((u64)b << 32 | a, key);
}
static inline u64 siphash_4u32(const u32 a, const u32 b, const u32 c,
			       const u32 d, const siphash_key_t *key)
{
	return siphash_2u64((u64)b << 32 | a, (u64)d << 32 | c, key);
}


static inline u64 ___siphash_aligned(const __le64 *data, size_t len,
				     const siphash_key_t *key)
{
	if (__builtin_constant_p(len) && len == 4)
		return siphash_1u32(le32_to_cpup((const __le32 *)data), key);
	if (__builtin_constant_p(len) && len == 8)
		return siphash_1u64(le64_to_cpu(data[0]), key);
	if (__builtin_constant_p(len) && len == 16)
		return siphash_2u64(le64_to_cpu(data[0]), le64_to_cpu(data[1]),
				    key);
	if (__builtin_constant_p(len) && len == 24)
		return siphash_3u64(le64_to_cpu(data[0]), le64_to_cpu(data[1]),
				    le64_to_cpu(data[2]), key);
	if (__builtin_constant_p(len) && len == 32)
		return siphash_4u64(le64_to_cpu(data[0]), le64_to_cpu(data[1]),
				    le64_to_cpu(data[2]), le64_to_cpu(data[3]),
				    key);
	return __siphash_aligned(data, len, key);
}

/**
 * siphash - compute 64-bit siphash PRF value
 * @data: buffer to hash
 * @size: size of @data
 * @key: the siphash key
 */
static inline u64 siphash(const void *data, size_t len,
			  const siphash_key_t *key)
{
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
	if (!IS_ALIGNED((unsigned long)data, SIPHASH_ALIGNMENT))
		return __siphash_unaligned(data, len, key);
#endif
	return ___siphash_aligned(data, len, key);
}

#define HSIPHASH_ALIGNMENT __alignof__(unsigned long)
typedef struct {
	unsigned long key[2];
} hsiphash_key_t;

u32 __hsiphash_aligned(const void *data, size_t len,
		       const hsiphash_key_t *key);
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
u32 __hsiphash_unaligned(const void *data, size_t len,
			 const hsiphash_key_t *key);
#endif

u32 hsiphash_1u32(const u32 a, const hsiphash_key_t *key);
u32 hsiphash_2u32(const u32 a, const u32 b, const hsiphash_key_t *key);
u32 hsiphash_3u32(const u32 a, const u32 b, const u32 c,
		  const hsiphash_key_t *key);
u32 hsiphash_4u32(const u32 a, const u32 b, const u32 c, const u32 d,
		  const hsiphash_key_t *key);

static inline u32 ___hsiphash_aligned(const __le32 *data, size_t len,
				      const hsiphash_key_t *key)
{
	if (__builtin_constant_p(len) && len == 4)
		return hsiphash_1u32(le32_to_cpu(data[0]), key);
	if (__builtin_constant_p(len) && len == 8)
		return hsiphash_2u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]),
				     key);
	if (__builtin_constant_p(len) && len == 12)
		return hsiphash_3u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]),
				     le32_to_cpu(data[2]), key);
	if (__builtin_constant_p(len) && len == 16)
		return hsiphash_4u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]),
				     le32_to_cpu(data[2]), le32_to_cpu(data[3]),
				     key);
	return __hsiphash_aligned(data, len, key);
}

/**
 * hsiphash - compute 32-bit hsiphash PRF value
 * @data: buffer to hash
 * @size: size of @data
 * @key: the hsiphash key
 */
static inline u32 hsiphash(const void *data, size_t len,
			   const hsiphash_key_t *key)
{
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
	if (!IS_ALIGNED((unsigned long)data, HSIPHASH_ALIGNMENT))
		return __hsiphash_unaligned(data, len, key);
#endif
	return ___hsiphash_aligned(data, len, key);
}

#endif /* _LINUX_SIPHASH_H */