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 * SPDX-License-Identifier: CC0-1.0 13 * -------------------------------------------------------------------------- 14 * HISTORY: 15 * 16 * 2020-10-03 (Sebastian Pipping) 17 * - Drop support for Visual Studio 9.0/2008 and earlier 18 * 19 * 2019-08-03 (Sebastian Pipping) 20 * - Mark part of sip24_valid as to be excluded from clang-format 21 * - Re-format code using clang-format 9 22 * 23 * 2018-07-08 (Anton Maklakov) 24 * - Add "fall through" markers for GCC's -Wimplicit-fallthrough 25 * 26 * 2017-11-03 (Sebastian Pipping) 27 * - Hide sip_tobin and sip_binof unless SIPHASH_TOBIN macro is defined 28 * 29 * 2017-07-25 (Vadim Zeitlin) 30 * - Fix use of SIPHASH_MAIN macro 31 * 32 * 2017-07-05 (Sebastian Pipping) 33 * - Use _SIP_ULL macro to not require a C++11 compiler if compiled as C++ 34 * - Add const qualifiers at two places 35 * - Ensure <=80 characters line length (assuming tab width 4) 36 * 37 * 2017-06-23 (Victor Stinner) 38 * - Address Win64 compile warnings 39 * 40 * 2017-06-18 (Sebastian Pipping) 41 * - Clarify license note in the header 42 * - Address C89 issues: 43 * - Stop using inline keyword (and let compiler decide) 44 * - Replace _Bool by int 45 * - Turn macro siphash24 into a function 46 * - Address invalid conversion (void pointer) by explicit cast 47 * - Address lack of stdint.h for Visual Studio 2003 to 2008 48 * - Always expose sip24_valid (for self-tests) 49 * 50 * 2012-11-04 - Born. (William Ahern) 51 * -------------------------------------------------------------------------- 52 * USAGE: 53 * 54 * SipHash-2-4 takes as input two 64-bit words as the key, some number of 55 * message bytes, and outputs a 64-bit word as the message digest. This 56 * implementation employs two data structures: a struct sipkey for 57 * representing the key, and a struct siphash for representing the hash 58 * state. 59 * 60 * For converting a 16-byte unsigned char array to a key, use either the 61 * macro sip_keyof or the routine sip_tokey. The former instantiates a 62 * compound literal key, while the latter requires a key object as a 63 * parameter. 64 * 65 * unsigned char secret[16]; 66 * arc4random_buf(secret, sizeof secret); 67 * struct sipkey *key = sip_keyof(secret); 68 * 69 * For hashing a message, use either the convenience macro siphash24 or the 70 * routines sip24_init, sip24_update, and sip24_final. 71 * 72 * struct siphash state; 73 * void *msg; 74 * size_t len; 75 * uint64_t hash; 76 * 77 * sip24_init(&state, key); 78 * sip24_update(&state, msg, len); 79 * hash = sip24_final(&state); 80 * 81 * or 82 * 83 * hash = siphash24(msg, len, key); 84 * 85 * To convert the 64-bit hash value to a canonical 8-byte little-endian 86 * binary representation, use either the macro sip_binof or the routine 87 * sip_tobin. The former instantiates and returns a compound literal array, 88 * while the latter requires an array object as a parameter. 89 * -------------------------------------------------------------------------- 90 * NOTES: 91 * 92 * o Neither sip_keyof, sip_binof, nor siphash24 will work with compilers 93 * lacking compound literal support. Instead, you must use the lower-level 94 * interfaces which take as parameters the temporary state objects. 95 * 96 * o Uppercase macros may evaluate parameters more than once. Lowercase 97 * macros should not exhibit any such side effects. 98 * ========================================================================== 99 */ 100 #ifndef SIPHASH_H 101 #define SIPHASH_H 102 103 #include <stddef.h> /* size_t */ 104 #include <stdint.h> /* uint64_t uint32_t uint8_t */ 105 #include "fallthrough.h" 106 107 /* 108 * Workaround to not require a C++11 compiler for using ULL suffix 109 * if this code is included and compiled as C++; related GCC warning is: 110 * warning: use of C++11 long long integer constant [-Wlong-long] 111 */ 112 #define SIP_ULL(high, low) ((((uint64_t)high) << 32) | (low)) 113 114 #define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b)))) 115 116 #define SIP_U32TO8_LE(p, v) \ 117 (p)[0] = (uint8_t)((v) >> 0); \ 118 (p)[1] = (uint8_t)((v) >> 8); \ 119 (p)[2] = (uint8_t)((v) >> 16); \ 120 (p)[3] = (uint8_t)((v) >> 24); 121 122 #define SIP_U64TO8_LE(p, v) \ 123 SIP_U32TO8_LE((p) + 0, (uint32_t)((v) >> 0)); \ 124 SIP_U32TO8_LE((p) + 4, (uint32_t)((v) >> 32)); 125 126 #define SIP_U8TO64_LE(p) \ 127 (((uint64_t)((p)[0]) << 0) | ((uint64_t)((p)[1]) << 8) \ 128 | ((uint64_t)((p)[2]) << 16) | ((uint64_t)((p)[3]) << 24) \ 129 | ((uint64_t)((p)[4]) << 32) | ((uint64_t)((p)[5]) << 40) \ 130 | ((uint64_t)((p)[6]) << 48) | ((uint64_t)((p)[7]) << 56)) 131 132 #define SIPHASH_INITIALIZER {0, 0, 0, 0, {0}, 0, 0} 133 134 struct siphash { 135 uint64_t v0, v1, v2, v3; 136 137 unsigned char buf[8], *p; 138 uint64_t c; 139 }; /* struct siphash */ 140 141 #define SIP_KEYLEN 16 142 143 struct sipkey { 144 uint64_t k[2]; 145 }; /* struct sipkey */ 146 147 #define sip_keyof(k) sip_tokey(&(struct sipkey){{0}}, (k)) 148 149 static struct sipkey * 150 sip_tokey(struct sipkey *key, const void *src) { 151 key->k[0] = SIP_U8TO64_LE((const unsigned char *)src); 152 key->k[1] = SIP_U8TO64_LE((const unsigned char *)src + 8); 153 return key; 154 } /* sip_tokey() */ 155 156 #ifdef SIPHASH_TOBIN 157 158 # define sip_binof(v) sip_tobin((unsigned char[8]){0}, (v)) 159 160 static void * 161 sip_tobin(void *dst, uint64_t u64) { 162 SIP_U64TO8_LE((unsigned char *)dst, u64); 163 return dst; 164 } /* sip_tobin() */ 165 166 #endif /* SIPHASH_TOBIN */ 167 168 static void 169 sip_round(struct siphash *H, const int rounds) { 170 int i; 171 172 for (i = 0; i < rounds; i++) { 173 H->v0 += H->v1; 174 H->v1 = SIP_ROTL(H->v1, 13); 175 H->v1 ^= H->v0; 176 H->v0 = SIP_ROTL(H->v0, 32); 177 178 H->v2 += H->v3; 179 H->v3 = SIP_ROTL(H->v3, 16); 180 H->v3 ^= H->v2; 181 182 H->v0 += H->v3; 183 H->v3 = SIP_ROTL(H->v3, 21); 184 H->v3 ^= H->v0; 185 186 H->v2 += H->v1; 187 H->v1 = SIP_ROTL(H->v1, 17); 188 H->v1 ^= H->v2; 189 H->v2 = SIP_ROTL(H->v2, 32); 190 } 191 } /* sip_round() */ 192 193 static struct siphash * 194 sip24_init(struct siphash *H, const struct sipkey *key) { 195 H->v0 = SIP_ULL(0x736f6d65U, 0x70736575U) ^ key->k[0]; 196 H->v1 = SIP_ULL(0x646f7261U, 0x6e646f6dU) ^ key->k[1]; 197 H->v2 = SIP_ULL(0x6c796765U, 0x6e657261U) ^ key->k[0]; 198 H->v3 = SIP_ULL(0x74656462U, 0x79746573U) ^ key->k[1]; 199 200 H->p = H->buf; 201 H->c = 0; 202 203 return H; 204 } /* sip24_init() */ 205 206 #define sip_endof(a) (&(a)[sizeof(a) / sizeof *(a)]) 207 208 static struct siphash * 209 sip24_update(struct siphash *H, const void *src, size_t len) { 210 const unsigned char *p = (const unsigned char *)src, *pe = p + len; 211 uint64_t m; 212 213 do { 214 while (p < pe && H->p < sip_endof(H->buf)) 215 *H->p++ = *p++; 216 217 if (H->p < sip_endof(H->buf)) 218 break; 219 220 m = SIP_U8TO64_LE(H->buf); 221 H->v3 ^= m; 222 sip_round(H, 2); 223 H->v0 ^= m; 224 225 H->p = H->buf; 226 H->c += 8; 227 } while (p < pe); 228 229 return H; 230 } /* sip24_update() */ 231 232 static uint64_t 233 sip24_final(struct siphash *H) { 234 const char left = (char)(H->p - H->buf); 235 uint64_t b = (H->c + left) << 56; 236 237 switch (left) { 238 case 7: 239 b |= (uint64_t)H->buf[6] << 48; 240 EXPAT_FALLTHROUGH; 241 case 6: 242 b |= (uint64_t)H->buf[5] << 40; 243 EXPAT_FALLTHROUGH; 244 case 5: 245 b |= (uint64_t)H->buf[4] << 32; 246 EXPAT_FALLTHROUGH; 247 case 4: 248 b |= (uint64_t)H->buf[3] << 24; 249 EXPAT_FALLTHROUGH; 250 case 3: 251 b |= (uint64_t)H->buf[2] << 16; 252 EXPAT_FALLTHROUGH; 253 case 2: 254 b |= (uint64_t)H->buf[1] << 8; 255 EXPAT_FALLTHROUGH; 256 case 1: 257 b |= (uint64_t)H->buf[0] << 0; 258 EXPAT_FALLTHROUGH; 259 case 0: 260 break; 261 } 262 263 H->v3 ^= b; 264 sip_round(H, 2); 265 H->v0 ^= b; 266 H->v2 ^= 0xff; 267 sip_round(H, 4); 268 269 return H->v0 ^ H->v1 ^ H->v2 ^ H->v3; 270 } /* sip24_final() */ 271 272 static uint64_t 273 siphash24(const void *src, size_t len, const struct sipkey *key) { 274 struct siphash state = SIPHASH_INITIALIZER; 275 return sip24_final(sip24_update(sip24_init(&state, key), src, len)); 276 } /* siphash24() */ 277 278 /* 279 * SipHash-2-4 output with 280 * k = 00 01 02 ... 281 * and 282 * in = (empty string) 283 * in = 00 (1 byte) 284 * in = 00 01 (2 bytes) 285 * in = 00 01 02 (3 bytes) 286 * ... 287 * in = 00 01 02 ... 3e (63 bytes) 288 */ 289 static int 290 sip24_valid(void) { 291 /* clang-format off */ 292 static const unsigned char vectors[64][8] = { 293 { 0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72, }, 294 { 0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74, }, 295 { 0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d, }, 296 { 0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85, }, 297 { 0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf, }, 298 { 0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18, }, 299 { 0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb, }, 300 { 0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab, }, 301 { 0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93, }, 302 { 0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e, }, 303 { 0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a, }, 304 { 0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4, }, 305 { 0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75, }, 306 { 0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14, }, 307 { 0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7, }, 308 { 0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1, }, 309 { 0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f, }, 310 { 0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69, }, 311 { 0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b, }, 312 { 0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb, }, 313 { 0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe, }, 314 { 0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0, }, 315 { 0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93, }, 316 { 0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8, }, 317 { 0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8, }, 318 { 0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc, }, 319 { 0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17, }, 320 { 0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f, }, 321 { 0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde, }, 322 { 0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6, }, 323 { 0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad, }, 324 { 0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32, }, 325 { 0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71, }, 326 { 0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7, }, 327 { 0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12, }, 328 { 0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15, }, 329 { 0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31, }, 330 { 0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02, }, 331 { 0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca, }, 332 { 0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a, }, 333 { 0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e, }, 334 { 0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad, }, 335 { 0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18, }, 336 { 0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4, }, 337 { 0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9, }, 338 { 0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9, }, 339 { 0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb, }, 340 { 0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0, }, 341 { 0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6, }, 342 { 0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7, }, 343 { 0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee, }, 344 { 0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1, }, 345 { 0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a, }, 346 { 0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81, }, 347 { 0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f, }, 348 { 0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24, }, 349 { 0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7, }, 350 { 0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea, }, 351 { 0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60, }, 352 { 0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66, }, 353 { 0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c, }, 354 { 0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f, }, 355 { 0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5, }, 356 { 0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95, } 357 }; 358 /* clang-format on */ 359 360 unsigned char in[64]; 361 struct sipkey k; 362 size_t i; 363 364 sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011" 365 "\012\013\014\015\016\017"); 366 367 for (i = 0; i < sizeof in; ++i) { 368 in[i] = (unsigned char)i; 369 370 if (siphash24(in, i, &k) != SIP_U8TO64_LE(vectors[i])) 371 return 0; 372 } 373 374 return 1; 375 } /* sip24_valid() */ 376 377 #ifdef SIPHASH_MAIN 378 379 # include <stdio.h> 380 381 int 382 main(void) { 383 const int ok = sip24_valid(); 384 385 if (ok) 386 puts("OK"); 387 else 388 puts("FAIL"); 389 390 return ! ok; 391 } /* main() */ 392 393 #endif /* SIPHASH_MAIN */ 394 395 #endif /* SIPHASH_H */ 396
Indexes created Tue Sep 29 00:26:59 UTC 2026