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Diffstat (limited to 'include/linux/siphash.h')
| -rw-r--r-- | include/linux/siphash.h | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/include/linux/siphash.h b/include/linux/siphash.h new file mode 100644 index 000000000000..fa7a6b9cedbf --- /dev/null +++ b/include/linux/siphash.h @@ -0,0 +1,140 @@ +/* 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 */ |