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. 6 * Minimal changes by Sebastian Pipping and Victor Stinner on top, see below. 7 * Licensed under the CC0 Public Domain Dedication license. 8 * 9 * 1. https://www.131002.net/siphash/siphash24.c 10 * 2. https://www.131002.net/siphash/ 11 * -------------------------------------------------------------------------- 12 * HISTORY: 13 * 14 * 2020-10-03 (Sebastian Pipping) 15 * - Drop support for Visual Studio 9.0/2008 and earlier 16 * 17 * 2019-08-03 (Sebastian Pipping) 18 * - Mark part of sip24_valid as to be excluded from clang-format 19 * - Re-format code using clang-format 9 20 * 21 * 2018-07-08 (Anton Maklakov) 22 * - Add "fall through" markers for GCC's -Wimplicit-fallthrough 23 * 24 * 2017-11-03 (Sebastian Pipping) 25 * - Hide sip_tobin and sip_binof unless SIPHASH_TOBIN macro is defined 26 * 27 * 2017-07-25 (Vadim Zeitlin) 28 * - Fix use of SIPHASH_MAIN macro 29 * 30 * 2017-07-05 (Sebastian Pipping) 31 * - Use _SIP_ULL macro to not require a C++11 compiler if compiled as C++ 32 * - Add const qualifiers at two places 33 * - Ensure <=80 characters line length (assuming tab width 4) 34 * 35 * 2017-06-23 (Victor Stinner) 36 * - Address Win64 compile warnings 37 * 38 * 2017-06-18 (Sebastian Pipping) 39 * - Clarify license note in the header 40 * - Address C89 issues: 41 * - Stop using inline keyword (and let compiler decide) 42 * - Replace _Bool by int 43 * - Turn macro siphash24 into a function 44 * - Address invalid conversion (void pointer) by explicit cast 45 * - Address lack of stdint.h for Visual Studio 2003 to 2008 46 * - Always expose sip24_valid (for self-tests) 47 * 48 * 2012-11-04 - Born. (William Ahern) 49 * -------------------------------------------------------------------------- 50 * USAGE: 51 * 52 * SipHash-2-4 takes as input two 64-bit words as the key, some number of 53 * message bytes, and outputs a 64-bit word as the message digest. This 54 * implementation employs two data structures: a struct sipkey for 55 * representing the key, and a struct siphash for representing the hash 56 * state. 57 * 58 * For converting a 16-byte unsigned char array to a key, use either the 59 * macro sip_keyof or the routine sip_tokey. The former instantiates a 60 * compound literal key, while the latter requires a key object as a 61 * parameter. 62 * 63 * unsigned char secret[16]; 64 * arc4random_buf(secret, sizeof secret); 65 * struct sipkey *key = sip_keyof(secret); 66 * 67 * For hashing a message, use either the convenience macro siphash24 or the 68 * routines sip24_init, sip24_update, and sip24_final. 69 * 70 * struct siphash state; 71 * void *msg; 72 * size_t len; 73 * uint64_t hash; 74 * 75 * sip24_init(&state, key); 76 * sip24_update(&state, msg, len); 77 * hash = sip24_final(&state); 78 * 79 * or 80 * 81 * hash = siphash24(msg, len, key); 82 * 83 * To convert the 64-bit hash value to a canonical 8-byte little-endian 84 * binary representation, use either the macro sip_binof or the routine 85 * sip_tobin. The former instantiates and returns a compound literal array, 86 * while the latter requires an array object as a parameter. 87 * -------------------------------------------------------------------------- 88 * NOTES: 89 * 90 * o Neither sip_keyof, sip_binof, nor siphash24 will work with compilers 91 * lacking compound literal support. Instead, you must use the lower-level 92 * interfaces which take as parameters the temporary state objects. 93 * 94 * o Uppercase macros may evaluate parameters more than once. Lowercase 95 * macros should not exhibit any such side effects. 96 * ========================================================================== 97 */ 98 #ifndef SIPHASH_H 99 #define SIPHASH_H 100 101 #include <stddef.h> /* size_t */ 102 #include <stdint.h> /* uint64_t uint32_t uint8_t */ 103 104 /* 105 * Workaround to not require a C++11 compiler for using ULL suffix 106 * if this code is included and compiled as C++; related GCC warning is: 107 * warning: use of C++11 long long integer constant [-Wlong-long] 108 */ 109 #define SIP_ULL(high, low) ((((uint64_t)high) << 32) | (low)) 110 111 #define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b)))) 112 113 #define SIP_U32TO8_LE(p, v) \ 114 (p)[0] = (uint8_t)((v) >> 0); \ 115 (p)[1] = (uint8_t)((v) >> 8); \ 116 (p)[2] = (uint8_t)((v) >> 16); \ 117 (p)[3] = (uint8_t)((v) >> 24); 118 119 #define SIP_U64TO8_LE(p, v) \ 120 SIP_U32TO8_LE((p) + 0, (uint32_t)((v) >> 0)); \ 121 SIP_U32TO8_LE((p) + 4, (uint32_t)((v) >> 32)); 122 123 #define SIP_U8TO64_LE(p) \ 124 (((uint64_t)((p)[0]) << 0) | ((uint64_t)((p)[1]) << 8) \ 125 | ((uint64_t)((p)[2]) << 16) | ((uint64_t)((p)[3]) << 24) \ 126 | ((uint64_t)((p)[4]) << 32) | ((uint64_t)((p)[5]) << 40) \ 127 | ((uint64_t)((p)[6]) << 48) | ((uint64_t)((p)[7]) << 56)) 128 129 #define SIPHASH_INITIALIZER {0, 0, 0, 0, {0}, 0, 0} 130 131 struct siphash { 132 uint64_t v0, v1, v2, v3; 133 134 unsigned char buf[8], *p; 135 uint64_t c; 136 }; /* struct siphash */ 137 138 #define SIP_KEYLEN 16 139 140 struct sipkey { 141 uint64_t k[2]; 142 }; /* struct sipkey */ 143 144 #define sip_keyof(k) sip_tokey(&(struct sipkey){{0}}, (k)) 145 146 static struct sipkey * 147 sip_tokey(struct sipkey *key, const void *src) { 148 key->k[0] = SIP_U8TO64_LE((const unsigned char *)src); 149 key->k[1] = SIP_U8TO64_LE((const unsigned char *)src + 8); 150 return key; 151 } /* sip_tokey() */ 152 153 #ifdef SIPHASH_TOBIN 154 155 # define sip_binof(v) sip_tobin((unsigned char[8]){0}, (v)) 156 157 static void * 158 sip_tobin(void *dst, uint64_t u64) { 159 SIP_U64TO8_LE((unsigned char *)dst, u64); 160 return dst; 161 } /* sip_tobin() */ 162 163 #endif /* SIPHASH_TOBIN */ 164 165 static void 166 sip_round(struct siphash *H, const int rounds) { 167 int i; 168 169 for (i = 0; i < rounds; i++) { 170 H->v0 += H->v1; 171 H->v1 = SIP_ROTL(H->v1, 13); 172 H->v1 ^= H->v0; 173 H->v0 = SIP_ROTL(H->v0, 32); 174 175 H->v2 += H->v3; 176 H->v3 = SIP_ROTL(H->v3, 16); 177 H->v3 ^= H->v2; 178 179 H->v0 += H->v3; 180 H->v3 = SIP_ROTL(H->v3, 21); 181 H->v3 ^= H->v0; 182 183 H->v2 += H->v1; 184 H->v1 = SIP_ROTL(H->v1, 17); 185 H->v1 ^= H->v2; 186 H->v2 = SIP_ROTL(H->v2, 32); 187 } 188 } /* sip_round() */ 189 190 static struct siphash * 191 sip24_init(struct siphash *H, const struct sipkey *key) { 192 H->v0 = SIP_ULL(0x736f6d65U, 0x70736575U) ^ key->k[0]; 193 H->v1 = SIP_ULL(0x646f7261U, 0x6e646f6dU) ^ key->k[1]; 194 H->v2 = SIP_ULL(0x6c796765U, 0x6e657261U) ^ key->k[0]; 195 H->v3 = SIP_ULL(0x74656462U, 0x79746573U) ^ key->k[1]; 196 197 H->p = H->buf; 198 H->c = 0; 199 200 return H; 201 } /* sip24_init() */ 202 203 #define sip_endof(a) (&(a)[sizeof(a) / sizeof *(a)]) 204 205 static struct siphash * 206 sip24_update(struct siphash *H, const void *src, size_t len) { 207 const unsigned char *p = (const unsigned char *)src, *pe = p + len; 208 uint64_t m; 209 210 do { 211 while (p < pe && H->p < sip_endof(H->buf)) 212 *H->p++ = *p++; 213 214 if (H->p < sip_endof(H->buf)) 215 break; 216 217 m = SIP_U8TO64_LE(H->buf); 218 H->v3 ^= m; 219 sip_round(H, 2); 220 H->v0 ^= m; 221 222 H->p = H->buf; 223 H->c += 8; 224 } while (p < pe); 225 226 return H; 227 } /* sip24_update() */ 228 229 static uint64_t 230 sip24_final(struct siphash *H) { 231 const char left = (char)(H->p - H->buf); 232 uint64_t b = (H->c + left) << 56; 233 234 switch (left) { 235 case 7: 236 b |= (uint64_t)H->buf[6] << 48; 237 /* fall through */ 238 case 6: 239 b |= (uint64_t)H->buf[5] << 40; 240 /* fall through */ 241 case 5: 242 b |= (uint64_t)H->buf[4] << 32; 243 /* fall through */ 244 case 4: 245 b |= (uint64_t)H->buf[3] << 24; 246 /* fall through */ 247 case 3: 248 b |= (uint64_t)H->buf[2] << 16; 249 /* fall through */ 250 case 2: 251 b |= (uint64_t)H->buf[1] << 8; 252 /* fall through */ 253 case 1: 254 b |= (uint64_t)H->buf[0] << 0; 255 /* fall through */ 256 case 0: 257 break; 258 } 259 260 H->v3 ^= b; 261 sip_round(H, 2); 262 H->v0 ^= b; 263 H->v2 ^= 0xff; 264 sip_round(H, 4); 265 266 return H->v0 ^ H->v1 ^ H->v2 ^ H->v3; 267 } /* sip24_final() */ 268 269 static uint64_t 270 siphash24(const void *src, size_t len, const struct sipkey *key) { 271 struct siphash state = SIPHASH_INITIALIZER; 272 return sip24_final(sip24_update(sip24_init(&state, key), src, len)); 273 } /* siphash24() */ 274 275 /* 276 * SipHash-2-4 output with 277 * k = 00 01 02 ... 278 * and 279 * in = (empty string) 280 * in = 00 (1 byte) 281 * in = 00 01 (2 bytes) 282 * in = 00 01 02 (3 bytes) 283 * ... 284 * in = 00 01 02 ... 3e (63 bytes) 285 */ 286 static int 287 sip24_valid(void) { 288 /* clang-format off */ 289 static const unsigned char vectors[64][8] = { 290 { 0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72, }, 291 { 0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74, }, 292 { 0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d, }, 293 { 0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85, }, 294 { 0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf, }, 295 { 0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18, }, 296 { 0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb, }, 297 { 0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab, }, 298 { 0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93, }, 299 { 0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e, }, 300 { 0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a, }, 301 { 0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4, }, 302 { 0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75, }, 303 { 0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14, }, 304 { 0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7, }, 305 { 0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1, }, 306 { 0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f, }, 307 { 0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69, }, 308 { 0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b, }, 309 { 0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb, }, 310 { 0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe, }, 311 { 0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0, }, 312 { 0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93, }, 313 { 0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8, }, 314 { 0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8, }, 315 { 0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc, }, 316 { 0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17, }, 317 { 0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f, }, 318 { 0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde, }, 319 { 0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6, }, 320 { 0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad, }, 321 { 0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32, }, 322 { 0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71, }, 323 { 0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7, }, 324 { 0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12, }, 325 { 0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15, }, 326 { 0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31, }, 327 { 0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02, }, 328 { 0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca, }, 329 { 0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a, }, 330 { 0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e, }, 331 { 0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad, }, 332 { 0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18, }, 333 { 0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4, }, 334 { 0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9, }, 335 { 0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9, }, 336 { 0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb, }, 337 { 0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0, }, 338 { 0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6, }, 339 { 0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7, }, 340 { 0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee, }, 341 { 0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1, }, 342 { 0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a, }, 343 { 0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81, }, 344 { 0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f, }, 345 { 0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24, }, 346 { 0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7, }, 347 { 0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea, }, 348 { 0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60, }, 349 { 0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66, }, 350 { 0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c, }, 351 { 0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f, }, 352 { 0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5, }, 353 { 0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95, } 354 }; 355 /* clang-format on */ 356 357 unsigned char in[64]; 358 struct sipkey k; 359 size_t i; 360 361 sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011" 362 "\012\013\014\015\016\017"); 363 364 for (i = 0; i < sizeof in; ++i) { 365 in[i] = (unsigned char)i; 366 367 if (siphash24(in, i, &k) != SIP_U8TO64_LE(vectors[i])) 368 return 0; 369 } 370 371 return 1; 372 } /* sip24_valid() */ 373 374 #ifdef SIPHASH_MAIN 375 376 # include <stdio.h> 377 378 int 379 main(void) { 380 const int ok = sip24_valid(); 381 382 if (ok) 383 puts("OK"); 384 else 385 puts("FAIL"); 386 387 return ! ok; 388 } /* main() */ 389 390 #endif /* SIPHASH_MAIN */ 391 392 #endif /* SIPHASH_H */ 393
Indexes created Thu Jun 11 00:25:07 UTC 2026