/* 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;
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 */
