siphash.h
1 /* ========================================================================== 2 * siphash.h - SipHash-2-4 in a single header file 3 * -------------------------------------------------------------------------- 4 * Derived by William Ahern from the reference implementation[1] published[2] 5 * by Jean-Philippe Aumasson and Daniel J. Berstein. Licensed in kind. 6 * 7 * 1. https://www.131002.net/siphash/siphash24.c 8 * 2. https://www.131002.net/siphash/ 9 * -------------------------------------------------------------------------- 10 * HISTORY: 11 * 12 * 2012-11-04 - Born. 13 * -------------------------------------------------------------------------- 14 * USAGE: 15 * 16 * SipHash-2-4 takes as input two 64-bit words as the key, some number of 17 * message bytes, and outputs a 64-bit word as the message digest. This 18 * implementation employs two data structures: a struct sipkey for 19 * representing the key, and a struct siphash for representing the hash 20 * state. 21 * 22 * For converting a 16-byte unsigned char array to a key, use either the 23 * macro sip_keyof or the routine sip_tokey. The former instantiates a 24 * compound literal key, while the latter requires a key object as a 25 * parameter. 26 * 27 * unsigned char secret[16]; 28 * arc4random_buf(secret, sizeof secret); 29 * struct sipkey *key = sip_keyof(secret); 30 * 31 * For hashing a message, use either the convenience macro siphash24 or the 32 * routines sip24_init, sip24_update, and sip24_final. 33 * 34 * struct siphash state; 35 * void *msg; 36 * size_t len; 37 * uint64_t hash; 38 * 39 * sip24_init(&state, key); 40 * sip24_update(&state, msg, len); 41 * hash = sip24_final(&state); 42 * 43 * or 44 * 45 * hash = siphash24(msg, len, key); 46 * 47 * To convert the 64-bit hash value to a canonical 8-byte little-endian 48 * binary representation, use either the macro sip_binof or the routine 49 * sip_tobin. The former instantiates and returns a compound literal array, 50 * while the latter requires an array object as a parameter. 51 * -------------------------------------------------------------------------- 52 * NOTES: 53 * 54 * o Neither sip_keyof, sip_binof, nor siphash24 will work with compilers 55 * lacking compound literal support. Instead, you must use the lower-level 56 * interfaces which take as parameters the temporary state objects. 57 * 58 * o Uppercase macros may evaluate parameters more than once. Lowercase 59 * macros should not exhibit any such side effects. 60 * ========================================================================== 61 */ 62 #ifndef SIPHASH_H 63 #define SIPHASH_H 64 65 #include <stddef.h> /* size_t */ 66 #include <stdint.h> /* uint64_t uint32_t uint8_t */ 67 68 69 #define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ( (x) >> (64 - (b)))) 70 71 #define SIP_U32TO8_LE(p, v) \ 72 (p)[0] = (uint8_t)((v) >> 0); (p)[1] = (uint8_t)((v) >> 8); \ 73 (p)[2] = (uint8_t)((v) >> 16); (p)[3] = (uint8_t)((v) >> 24); 74 75 #define SIP_U64TO8_LE(p, v) \ 76 SIP_U32TO8_LE((p) + 0, (uint32_t)((v) >> 0)); \ 77 SIP_U32TO8_LE((p) + 4, (uint32_t)((v) >> 32)); 78 79 #define SIP_U8TO64_LE(p) \ 80 (((uint64_t)((p)[0]) << 0) | \ 81 ((uint64_t)((p)[1]) << 8) | \ 82 ((uint64_t)((p)[2]) << 16) | \ 83 ((uint64_t)((p)[3]) << 24) | \ 84 ((uint64_t)((p)[4]) << 32) | \ 85 ((uint64_t)((p)[5]) << 40) | \ 86 ((uint64_t)((p)[6]) << 48) | \ 87 ((uint64_t)((p)[7]) << 56)) 88 89 90 #define SIPHASH_INITIALIZER { 0, 0, 0, 0, { 0 }, 0, 0 } 91 92 struct siphash { 93 uint64_t v0, v1, v2, v3; 94 95 unsigned char buf[8], *p; 96 uint64_t c; 97 }; /* struct siphash */ 98 99 100 #define SIP_KEYLEN 16 101 102 struct sipkey { 103 uint64_t k[2]; 104 }; /* struct sipkey */ 105 106 #define sip_keyof(k) sip_tokey(&(struct sipkey){ { 0 } }, (k)) 107 108 static inline struct sipkey *sip_tokey(struct sipkey *key, const void *src) { 109 key->k[0] = SIP_U8TO64_LE((const unsigned char *)src); 110 key->k[1] = SIP_U8TO64_LE((const unsigned char *)src + 8); 111 return key; 112 } /* sip_tokey() */ 113 114 115 #define sip_binof(v) sip_tobin((unsigned char[8]){ 0 }, (v)) 116 117 static inline void *sip_tobin(void *dst, uint64_t u64) { 118 SIP_U64TO8_LE((unsigned char *)dst, u64); 119 return dst; 120 } /* sip_tobin() */ 121 122 123 static inline void sip_round(struct siphash *H, const int rounds) { 124 int i; 125 126 for (i = 0; i < rounds; i++) { 127 H->v0 += H->v1; 128 H->v1 = SIP_ROTL(H->v1, 13); 129 H->v1 ^= H->v0; 130 H->v0 = SIP_ROTL(H->v0, 32); 131 132 H->v2 += H->v3; 133 H->v3 = SIP_ROTL(H->v3, 16); 134 H->v3 ^= H->v2; 135 136 H->v0 += H->v3; 137 H->v3 = SIP_ROTL(H->v3, 21); 138 H->v3 ^= H->v0; 139 140 H->v2 += H->v1; 141 H->v1 = SIP_ROTL(H->v1, 17); 142 H->v1 ^= H->v2; 143 H->v2 = SIP_ROTL(H->v2, 32); 144 } 145 } /* sip_round() */ 146 147 148 static inline struct siphash *sip24_init(struct siphash *H, const struct sipkey *key) { 149 H->v0 = 0x736f6d6570736575ULL ^ key->k[0]; 150 H->v1 = 0x646f72616e646f6dULL ^ key->k[1]; 151 H->v2 = 0x6c7967656e657261ULL ^ key->k[0]; 152 H->v3 = 0x7465646279746573ULL ^ key->k[1]; 153 154 H->p = H->buf; 155 H->c = 0; 156 157 return H; 158 } /* sip24_init() */ 159 160 161 #define sip_endof(a) (&(a)[sizeof (a) / sizeof *(a)]) 162 163 static inline struct siphash *sip24_update(struct siphash *H, const void *src, size_t len) { 164 const unsigned char *p = src, *pe = p + len; 165 uint64_t m; 166 167 do { 168 while (p < pe && H->p < sip_endof(H->buf)) 169 *H->p++ = *p++; 170 171 if (H->p < sip_endof(H->buf)) 172 break; 173 174 m = SIP_U8TO64_LE(H->buf); 175 H->v3 ^= m; 176 sip_round(H, 2); 177 H->v0 ^= m; 178 179 H->p = H->buf; 180 H->c += 8; 181 } while (p < pe); 182 183 return H; 184 } /* sip24_update() */ 185 186 187 static inline uint64_t sip24_final(struct siphash *H) { 188 char left = H->p - H->buf; 189 uint64_t b = (H->c + left) << 56; 190 191 switch (left) { 192 case 7: b |= (uint64_t)H->buf[6] << 48; /* FALLTHRU */ 193 case 6: b |= (uint64_t)H->buf[5] << 40; /* FALLTHRU */ 194 case 5: b |= (uint64_t)H->buf[4] << 32; /* FALLTHRU */ 195 case 4: b |= (uint64_t)H->buf[3] << 24; /* FALLTHRU */ 196 case 3: b |= (uint64_t)H->buf[2] << 16; /* FALLTHRU */ 197 case 2: b |= (uint64_t)H->buf[1] << 8; /* FALLTHRU */ 198 case 1: b |= (uint64_t)H->buf[0] << 0; /* FALLTHRU */ 199 case 0: break; 200 } 201 202 H->v3 ^= b; 203 sip_round(H, 2); 204 H->v0 ^= b; 205 H->v2 ^= 0xff; 206 sip_round(H, 4); 207 208 return H->v0 ^ H->v1 ^ H->v2 ^ H->v3; 209 } /* sip24_final() */ 210 211 212 #define siphash24(src, len, key) \ 213 sip24_final(sip24_update(sip24_init(&(struct siphash)SIPHASH_INITIALIZER, (key)), (src), (len))) 214 215 216 #if SIPHASH_MAIN 217 218 /* 219 * SipHash-2-4 output with 220 * k = 00 01 02 ... 221 * and 222 * in = (empty string) 223 * in = 00 (1 byte) 224 * in = 00 01 (2 bytes) 225 * in = 00 01 02 (3 bytes) 226 * ... 227 * in = 00 01 02 ... 3e (63 bytes) 228 */ 229 static inline _Bool sip24_valid(void) { 230 static const unsigned char vectors[64][8] = { 231 { 0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72, }, 232 { 0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74, }, 233 { 0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d, }, 234 { 0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85, }, 235 { 0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf, }, 236 { 0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18, }, 237 { 0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb, }, 238 { 0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab, }, 239 { 0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93, }, 240 { 0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e, }, 241 { 0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a, }, 242 { 0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4, }, 243 { 0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75, }, 244 { 0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14, }, 245 { 0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7, }, 246 { 0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1, }, 247 { 0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f, }, 248 { 0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69, }, 249 { 0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b, }, 250 { 0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb, }, 251 { 0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe, }, 252 { 0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0, }, 253 { 0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93, }, 254 { 0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8, }, 255 { 0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8, }, 256 { 0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc, }, 257 { 0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17, }, 258 { 0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f, }, 259 { 0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde, }, 260 { 0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6, }, 261 { 0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad, }, 262 { 0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32, }, 263 { 0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71, }, 264 { 0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7, }, 265 { 0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12, }, 266 { 0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15, }, 267 { 0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31, }, 268 { 0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02, }, 269 { 0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca, }, 270 { 0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a, }, 271 { 0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e, }, 272 { 0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad, }, 273 { 0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18, }, 274 { 0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4, }, 275 { 0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9, }, 276 { 0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9, }, 277 { 0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb, }, 278 { 0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0, }, 279 { 0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6, }, 280 { 0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7, }, 281 { 0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee, }, 282 { 0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1, }, 283 { 0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a, }, 284 { 0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81, }, 285 { 0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f, }, 286 { 0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24, }, 287 { 0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7, }, 288 { 0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea, }, 289 { 0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60, }, 290 { 0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66, }, 291 { 0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c, }, 292 { 0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f, }, 293 { 0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5, }, 294 { 0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95, } 295 }; 296 unsigned char in[64]; 297 struct sipkey k; 298 size_t i; 299 300 sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017"); 301 302 for (i = 0; i < sizeof in; ++i) { 303 in[i] = i; 304 305 if (siphash24(in, i, &k) != SIP_U8TO64_LE(vectors[i])) 306 return 0; 307 } 308 309 return 1; 310 } /* sip24_valid() */ 311 312 313 #include <stdio.h> 314 315 int main(void) { 316 _Bool ok = sip24_valid(); 317 318 if (ok) 319 puts("OK"); 320 else 321 puts("FAIL"); 322 323 return !ok; 324 } /* main() */ 325 326 #endif /* SIPHASH_MAIN */ 327 328 329 #endif /* SIPHASH_H */