1 /* Copyright (C) 2016 Jason A. Donenfeld <[email protected]>. All Rights Reserved. 2 * 3 * This file is provided under a dual BSD/GPLv2 license. 4 * 5 * SipHash: a fast short-input PRF 6 * https://131002.net/siphash/ 7 * 8 * This implementation is specifically for SipHash2-4 for a secure PRF 9 * and HalfSipHash1-3/SipHash1-3 for an insecure PRF only suitable for 10 * hashtables. 11 */ 12 13 #ifndef _LINUX_SIPHASH_H 14 #define _LINUX_SIPHASH_H 15 16 #include <linux/types.h> 17 #include <linux/kernel.h> 18 19 #define SIPHASH_ALIGNMENT __alignof__(u64) 20 typedef struct { 21 u64 key[2]; 22 } siphash_key_t; 23 24 #define siphash_aligned_key_t siphash_key_t __aligned(16) 25 26 static inline bool siphash_key_is_zero(const siphash_key_t *key) 27 { 28 return !(key->key[0] | key->key[1]); 29 } 30 31 u64 __siphash_aligned(const void *data, size_t len, const siphash_key_t *key); 32 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 33 u64 __siphash_unaligned(const void *data, size_t len, const siphash_key_t *key); 34 #endif 35 36 u64 siphash_1u64(const u64 a, const siphash_key_t *key); 37 u64 siphash_2u64(const u64 a, const u64 b, const siphash_key_t *key); 38 u64 siphash_3u64(const u64 a, const u64 b, const u64 c, 39 const siphash_key_t *key); 40 u64 siphash_4u64(const u64 a, const u64 b, const u64 c, const u64 d, 41 const siphash_key_t *key); 42 u64 siphash_1u32(const u32 a, const siphash_key_t *key); 43 u64 siphash_3u32(const u32 a, const u32 b, const u32 c, 44 const siphash_key_t *key); 45 46 static inline u64 siphash_2u32(const u32 a, const u32 b, 47 const siphash_key_t *key) 48 { 49 return siphash_1u64((u64)b << 32 | a, key); 50 } 51 static inline u64 siphash_4u32(const u32 a, const u32 b, const u32 c, 52 const u32 d, const siphash_key_t *key) 53 { 54 return siphash_2u64((u64)b << 32 | a, (u64)d << 32 | c, key); 55 } 56 57 58 static inline u64 ___siphash_aligned(const __le64 *data, size_t len, 59 const siphash_key_t *key) 60 { 61 if (__builtin_constant_p(len) && len == 4) 62 return siphash_1u32(le32_to_cpup((const __le32 *)data), key); 63 if (__builtin_constant_p(len) && len == 8) 64 return siphash_1u64(le64_to_cpu(data[0]), key); 65 if (__builtin_constant_p(len) && len == 16) 66 return siphash_2u64(le64_to_cpu(data[0]), le64_to_cpu(data[1]), 67 key); 68 if (__builtin_constant_p(len) && len == 24) 69 return siphash_3u64(le64_to_cpu(data[0]), le64_to_cpu(data[1]), 70 le64_to_cpu(data[2]), key); 71 if (__builtin_constant_p(len) && len == 32) 72 return siphash_4u64(le64_to_cpu(data[0]), le64_to_cpu(data[1]), 73 le64_to_cpu(data[2]), le64_to_cpu(data[3]), 74 key); 75 return __siphash_aligned(data, len, key); 76 } 77 78 /** 79 * siphash - compute 64-bit siphash PRF value 80 * @data: buffer to hash 81 * @size: size of @data 82 * @key: the siphash key 83 */ 84 static inline u64 siphash(const void *data, size_t len, 85 const siphash_key_t *key) 86 { 87 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 88 if (!IS_ALIGNED((unsigned long)data, SIPHASH_ALIGNMENT)) 89 return __siphash_unaligned(data, len, key); 90 #endif 91 return ___siphash_aligned(data, len, key); 92 } 93 94 #define HSIPHASH_ALIGNMENT __alignof__(unsigned long) 95 typedef struct { 96 unsigned long key[2]; 97 } hsiphash_key_t; 98 99 u32 __hsiphash_aligned(const void *data, size_t len, 100 const hsiphash_key_t *key); 101 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 102 u32 __hsiphash_unaligned(const void *data, size_t len, 103 const hsiphash_key_t *key); 104 #endif 105 106 u32 hsiphash_1u32(const u32 a, const hsiphash_key_t *key); 107 u32 hsiphash_2u32(const u32 a, const u32 b, const hsiphash_key_t *key); 108 u32 hsiphash_3u32(const u32 a, const u32 b, const u32 c, 109 const hsiphash_key_t *key); 110 u32 hsiphash_4u32(const u32 a, const u32 b, const u32 c, const u32 d, 111 const hsiphash_key_t *key); 112 113 static inline u32 ___hsiphash_aligned(const __le32 *data, size_t len, 114 const hsiphash_key_t *key) 115 { 116 if (__builtin_constant_p(len) && len == 4) 117 return hsiphash_1u32(le32_to_cpu(data[0]), key); 118 if (__builtin_constant_p(len) && len == 8) 119 return hsiphash_2u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]), 120 key); 121 if (__builtin_constant_p(len) && len == 12) 122 return hsiphash_3u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]), 123 le32_to_cpu(data[2]), key); 124 if (__builtin_constant_p(len) && len == 16) 125 return hsiphash_4u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]), 126 le32_to_cpu(data[2]), le32_to_cpu(data[3]), 127 key); 128 return __hsiphash_aligned(data, len, key); 129 } 130 131 /** 132 * hsiphash - compute 32-bit hsiphash PRF value 133 * @data: buffer to hash 134 * @size: size of @data 135 * @key: the hsiphash key 136 */ 137 static inline u32 hsiphash(const void *data, size_t len, 138 const hsiphash_key_t *key) 139 { 140 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 141 if (!IS_ALIGNED((unsigned long)data, HSIPHASH_ALIGNMENT)) 142 return __hsiphash_unaligned(data, len, key); 143 #endif 144 return ___hsiphash_aligned(data, len, key); 145 } 146 147 #endif /* _LINUX_SIPHASH_H */ 148