csiphash.c (4300B)
1 /* <MIT License> 2 Copyright (c) 2013-2014 Marek Majkowski <marek@popcount.org> 3 4 Permission is hereby granted, free of charge, to any person obtaining a copy 5 of this software and associated documentation files (the "Software"), to deal 6 in the Software without restriction, including without limitation the rights 7 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 8 copies of the Software, and to permit persons to whom the Software is 9 furnished to do so, subject to the following conditions: 10 11 The above copyright notice and this permission notice shall be included in 12 all copies or substantial portions of the Software. 13 14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 15 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 17 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 18 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 19 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 20 THE SOFTWARE. 21 </MIT License> 22 23 Original location: 24 https://github.com/majek/csiphash/ 25 26 Solution inspired by code from: 27 Samuel Neves (supercop/crypto_auth/siphash24/little) 28 djb (supercop/crypto_auth/siphash24/little2) 29 Jean-Philippe Aumasson (https://131002.net/siphash/siphash24.c) 30 */ 31 32 #include "lib/cc/torint.h" 33 #include "lib/err/torerr.h" 34 35 #include "ext/siphash.h" 36 #include <string.h> 37 #include <stdlib.h> 38 #include "ext/byteorder.h" 39 40 #define ROTATE(x, b) (uint64_t)( ((x) << (b)) | ( (x) >> (64 - (b))) ) 41 42 #define HALF_ROUND(a,b,c,d,s,t) \ 43 a += b; c += d; \ 44 b = ROTATE(b, s) ^ a; \ 45 d = ROTATE(d, t) ^ c; \ 46 a = ROTATE(a, 32); 47 48 #define DOUBLE_ROUND(v0,v1,v2,v3) \ 49 HALF_ROUND(v0,v1,v2,v3,13,16); \ 50 HALF_ROUND(v2,v1,v0,v3,17,21); \ 51 HALF_ROUND(v0,v1,v2,v3,13,16); \ 52 HALF_ROUND(v2,v1,v0,v3,17,21); 53 54 #if 0 55 /* This does not seem to save very much runtime in the fast case, and it's 56 * potentially a big loss in the slow case where we're misaligned and we cross 57 * a cache line. */ 58 #if (defined(__i386) || defined(__i386__) || defined(_M_IX86) || \ 59 defined(__x86_64) || defined(__x86_64__) || \ 60 defined(_M_AMD64) || defined(_M_X64) || defined(__INTEL__)) 61 # define UNALIGNED_OK 1 62 #endif 63 #endif 64 65 uint64_t siphash24(const void *src, unsigned long src_sz, const struct sipkey *key) { 66 const uint8_t *m = src; 67 uint64_t k0 = key->k0; 68 uint64_t k1 = key->k1; 69 uint64_t last7 = (uint64_t)(src_sz & 0xff) << 56; 70 size_t i, blocks; 71 72 uint64_t v0 = k0 ^ 0x736f6d6570736575ULL; 73 uint64_t v1 = k1 ^ 0x646f72616e646f6dULL; 74 uint64_t v2 = k0 ^ 0x6c7967656e657261ULL; 75 uint64_t v3 = k1 ^ 0x7465646279746573ULL; 76 77 for (i = 0, blocks = (src_sz & ~7); i < blocks; i+= 8) { 78 #ifdef UNALIGNED_OK 79 uint64_t mi = _le64toh(*(m + i)); 80 #else 81 uint64_t mi; 82 memcpy(&mi, m + i, 8); 83 mi = _le64toh(mi); 84 #endif 85 v3 ^= mi; 86 DOUBLE_ROUND(v0,v1,v2,v3); 87 v0 ^= mi; 88 } 89 90 #ifdef __COVERITY__ 91 { 92 uint64_t mi = 0; 93 memcpy(&mi, m+i, (src_sz-blocks)); 94 last7 = _le64toh(mi) | (uint64_t)(src_sz & 0xff) << 56; 95 } 96 #else 97 switch (src_sz - blocks) { 98 case 7: last7 |= (uint64_t)m[i + 6] << 48; FALLTHROUGH; 99 case 6: last7 |= (uint64_t)m[i + 5] << 40; FALLTHROUGH; 100 case 5: last7 |= (uint64_t)m[i + 4] << 32; FALLTHROUGH; 101 case 4: last7 |= (uint64_t)m[i + 3] << 24; FALLTHROUGH; 102 case 3: last7 |= (uint64_t)m[i + 2] << 16; FALLTHROUGH; 103 case 2: last7 |= (uint64_t)m[i + 1] << 8; FALLTHROUGH; 104 case 1: last7 |= (uint64_t)m[i + 0] ; FALLTHROUGH; 105 case 0: 106 default:; 107 } 108 #endif 109 v3 ^= last7; 110 DOUBLE_ROUND(v0,v1,v2,v3); 111 v0 ^= last7; 112 v2 ^= 0xff; 113 DOUBLE_ROUND(v0,v1,v2,v3); 114 DOUBLE_ROUND(v0,v1,v2,v3); 115 return v0 ^ v1 ^ v2 ^ v3; 116 } 117 118 119 static int the_siphash_key_is_set = 0; 120 static struct sipkey the_siphash_key; 121 122 uint64_t siphash24g(const void *src, unsigned long src_sz) { 123 raw_assert(the_siphash_key_is_set); 124 return siphash24(src, src_sz, &the_siphash_key); 125 } 126 127 void siphash_set_global_key(const struct sipkey *key) 128 { 129 raw_assert(! the_siphash_key_is_set); 130 the_siphash_key.k0 = key->k0; 131 the_siphash_key.k1 = key->k1; 132 the_siphash_key_is_set = 1; 133 } 134 135 void siphash_unset_global_key(void) 136 { 137 the_siphash_key_is_set = 0; 138 memset(&the_siphash_key, 0, sizeof(the_siphash_key)); 139 }