86 lines
2.7 KiB
C
86 lines
2.7 KiB
C
|
/* 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#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;
|
||
|
|
|
||
|
|
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);
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* _LINUX_SIPHASH_H */
|