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      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  * 2018-07-08  (Anton Maklakov)
     15  *   - Add "fall through" markers for GCC's -Wimplicit-fallthrough
     16  *
     17  * 2017-11-03  (Sebastian Pipping)
     18  *   - Hide sip_tobin and sip_binof unless SIPHASH_TOBIN macro is defined
     19  *
     20  * 2017-07-25  (Vadim Zeitlin)
     21  *   - Fix use of SIPHASH_MAIN macro
     22  *
     23  * 2017-07-05  (Sebastian Pipping)
     24  *   - Use _SIP_ULL macro to not require a C++11 compiler if compiled as C++
     25  *   - Add const qualifiers at two places
     26  *   - Ensure <=80 characters line length (assuming tab width 4)
     27  *
     28  * 2017-06-23  (Victor Stinner)
     29  *   - Address Win64 compile warnings
     30  *
     31  * 2017-06-18  (Sebastian Pipping)
     32  *   - Clarify license note in the header
     33  *   - Address C89 issues:
     34  *     - Stop using inline keyword (and let compiler decide)
     35  *     - Replace _Bool by int
     36  *     - Turn macro siphash24 into a function
     37  *     - Address invalid conversion (void pointer) by explicit cast
     38  *   - Address lack of stdint.h for Visual Studio 2003 to 2008
     39  *   - Always expose sip24_valid (for self-tests)
     40  *
     41  * 2012-11-04 - Born.  (William Ahern)
     42  * --------------------------------------------------------------------------
     43  * USAGE:
     44  *
     45  * SipHash-2-4 takes as input two 64-bit words as the key, some number of
     46  * message bytes, and outputs a 64-bit word as the message digest. This
     47  * implementation employs two data structures: a struct sipkey for
     48  * representing the key, and a struct siphash for representing the hash
     49  * state.
     50  *
     51  * For converting a 16-byte unsigned char array to a key, use either the
     52  * macro sip_keyof or the routine sip_tokey. The former instantiates a
     53  * compound literal key, while the latter requires a key object as a
     54  * parameter.
     55  *
     56  * 	unsigned char secret[16];
     57  * 	arc4random_buf(secret, sizeof secret);
     58  * 	struct sipkey *key = sip_keyof(secret);
     59  *
     60  * For hashing a message, use either the convenience macro siphash24 or the
     61  * routines sip24_init, sip24_update, and sip24_final.
     62  *
     63  * 	struct siphash state;
     64  * 	void *msg;
     65  * 	size_t len;
     66  * 	uint64_t hash;
     67  *
     68  * 	sip24_init(&state, key);
     69  * 	sip24_update(&state, msg, len);
     70  * 	hash = sip24_final(&state);
     71  *
     72  * or
     73  *
     74  * 	hash = siphash24(msg, len, key);
     75  *
     76  * To convert the 64-bit hash value to a canonical 8-byte little-endian
     77  * binary representation, use either the macro sip_binof or the routine
     78  * sip_tobin. The former instantiates and returns a compound literal array,
     79  * while the latter requires an array object as a parameter.
     80  * --------------------------------------------------------------------------
     81  * NOTES:
     82  *
     83  * o Neither sip_keyof, sip_binof, nor siphash24 will work with compilers
     84  *   lacking compound literal support. Instead, you must use the lower-level
     85  *   interfaces which take as parameters the temporary state objects.
     86  *
     87  * o Uppercase macros may evaluate parameters more than once. Lowercase
     88  *   macros should not exhibit any such side effects.
     89  * ==========================================================================
     90  */
     91 #ifndef SIPHASH_H
     92 #define SIPHASH_H
     93 
     94 #include <stddef.h> /* size_t */
     95 
     96 #if defined(_WIN32) && defined(_MSC_VER) && (_MSC_VER < 1600)
     97   /* For vs2003/7.1 up to vs2008/9.0; _MSC_VER 1600 is vs2010/10.0 */
     98   typedef unsigned __int8   uint8_t;
     99   typedef unsigned __int32 uint32_t;
    100   typedef unsigned __int64 uint64_t;
    101 #else
    102  #include <stdint.h> /* uint64_t uint32_t uint8_t */
    103 #endif
    104 
    105 
    106 /*
    107  * Workaround to not require a C++11 compiler for using ULL suffix
    108  * if this code is included and compiled as C++; related GCC warning is:
    109  * warning: use of C++11 long long integer constant [-Wlong-long]
    110  */
    111 #define _SIP_ULL(high, low)  (((uint64_t)high << 32) | low)
    112 
    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); (p)[1] = (uint8_t)((v) >>  8); \
    118 	(p)[2] = (uint8_t)((v) >> 16); (p)[3] = (uint8_t)((v) >> 24);
    119 
    120 #define SIP_U64TO8_LE(p, v) \
    121 	SIP_U32TO8_LE((p) + 0, (uint32_t)((v) >>  0)); \
    122 	SIP_U32TO8_LE((p) + 4, (uint32_t)((v) >> 32));
    123 
    124 #define SIP_U8TO64_LE(p) \
    125 	(((uint64_t)((p)[0]) <<  0) | \
    126 	 ((uint64_t)((p)[1]) <<  8) | \
    127 	 ((uint64_t)((p)[2]) << 16) | \
    128 	 ((uint64_t)((p)[3]) << 24) | \
    129 	 ((uint64_t)((p)[4]) << 32) | \
    130 	 ((uint64_t)((p)[5]) << 40) | \
    131 	 ((uint64_t)((p)[6]) << 48) | \
    132 	 ((uint64_t)((p)[7]) << 56))
    133 
    134 
    135 #define SIPHASH_INITIALIZER { 0, 0, 0, 0, { 0 }, 0, 0 }
    136 
    137 struct siphash {
    138 	uint64_t v0, v1, v2, v3;
    139 
    140 	unsigned char buf[8], *p;
    141 	uint64_t c;
    142 }; /* struct siphash */
    143 
    144 
    145 #define SIP_KEYLEN 16
    146 
    147 struct sipkey {
    148 	uint64_t k[2];
    149 }; /* struct sipkey */
    150 
    151 #define sip_keyof(k) sip_tokey(&(struct sipkey){ { 0 } }, (k))
    152 
    153 static struct sipkey *sip_tokey(struct sipkey *key, const void *src) {
    154 	key->k[0] = SIP_U8TO64_LE((const unsigned char *)src);
    155 	key->k[1] = SIP_U8TO64_LE((const unsigned char *)src + 8);
    156 	return key;
    157 } /* sip_tokey() */
    158 
    159 
    160 #ifdef SIPHASH_TOBIN
    161 
    162 #define sip_binof(v) sip_tobin((unsigned char[8]){ 0 }, (v))
    163 
    164 static void *sip_tobin(void *dst, uint64_t u64) {
    165 	SIP_U64TO8_LE((unsigned char *)dst, u64);
    166 	return dst;
    167 } /* sip_tobin() */
    168 
    169 #endif  /* SIPHASH_TOBIN */
    170 
    171 
    172 static void sip_round(struct siphash *H, const int rounds) {
    173 	int i;
    174 
    175 	for (i = 0; i < rounds; i++) {
    176 		H->v0 += H->v1;
    177 		H->v1 = SIP_ROTL(H->v1, 13);
    178 		H->v1 ^= H->v0;
    179 		H->v0 = SIP_ROTL(H->v0, 32);
    180 
    181 		H->v2 += H->v3;
    182 		H->v3 = SIP_ROTL(H->v3, 16);
    183 		H->v3 ^= H->v2;
    184 
    185 		H->v0 += H->v3;
    186 		H->v3 = SIP_ROTL(H->v3, 21);
    187 		H->v3 ^= H->v0;
    188 
    189 		H->v2 += H->v1;
    190 		H->v1 = SIP_ROTL(H->v1, 17);
    191 		H->v1 ^= H->v2;
    192 		H->v2 = SIP_ROTL(H->v2, 32);
    193 	}
    194 } /* sip_round() */
    195 
    196 
    197 static struct siphash *sip24_init(struct siphash *H,
    198 		const struct sipkey *key) {
    199 	H->v0 = _SIP_ULL(0x736f6d65U, 0x70736575U) ^ key->k[0];
    200 	H->v1 = _SIP_ULL(0x646f7261U, 0x6e646f6dU) ^ key->k[1];
    201 	H->v2 = _SIP_ULL(0x6c796765U, 0x6e657261U) ^ key->k[0];
    202 	H->v3 = _SIP_ULL(0x74656462U, 0x79746573U) ^ key->k[1];
    203 
    204 	H->p = H->buf;
    205 	H->c = 0;
    206 
    207 	return H;
    208 } /* sip24_init() */
    209 
    210 
    211 #define sip_endof(a) (&(a)[sizeof (a) / sizeof *(a)])
    212 
    213 static struct siphash *sip24_update(struct siphash *H, const void *src,
    214 		size_t len) {
    215 	const unsigned char *p = (const unsigned char *)src, *pe = p + len;
    216 	uint64_t m;
    217 
    218 	do {
    219 		while (p < pe && H->p < sip_endof(H->buf))
    220 			*H->p++ = *p++;
    221 
    222 		if (H->p < sip_endof(H->buf))
    223 			break;
    224 
    225 		m = SIP_U8TO64_LE(H->buf);
    226 		H->v3 ^= m;
    227 		sip_round(H, 2);
    228 		H->v0 ^= m;
    229 
    230 		H->p = H->buf;
    231 		H->c += 8;
    232 	} while (p < pe);
    233 
    234 	return H;
    235 } /* sip24_update() */
    236 
    237 
    238 static uint64_t sip24_final(struct siphash *H) {
    239 	const char left = (char)(H->p - H->buf);
    240 	uint64_t b = (H->c + left) << 56;
    241 
    242 	switch (left) {
    243 	case 7: b |= (uint64_t)H->buf[6] << 48;
    244 		/* fall through */
    245 	case 6: b |= (uint64_t)H->buf[5] << 40;
    246 		/* fall through */
    247 	case 5: b |= (uint64_t)H->buf[4] << 32;
    248 		/* fall through */
    249 	case 4: b |= (uint64_t)H->buf[3] << 24;
    250 		/* fall through */
    251 	case 3: b |= (uint64_t)H->buf[2] << 16;
    252 		/* fall through */
    253 	case 2: b |= (uint64_t)H->buf[1] << 8;
    254 		/* fall through */
    255 	case 1: b |= (uint64_t)H->buf[0] << 0;
    256 		/* fall through */
    257 	case 0: 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 
    270 static uint64_t siphash24(const void *src, size_t len,
    271 		const struct sipkey *key) {
    272 	struct siphash state = SIPHASH_INITIALIZER;
    273 	return sip24_final(sip24_update(sip24_init(&state, key), src, len));
    274 } /* siphash24() */
    275 
    276 
    277 /*
    278  * SipHash-2-4 output with
    279  * k = 00 01 02 ...
    280  * and
    281  * in = (empty string)
    282  * in = 00 (1 byte)
    283  * in = 00 01 (2 bytes)
    284  * in = 00 01 02 (3 bytes)
    285  * ...
    286  * in = 00 01 02 ... 3e (63 bytes)
    287  */
    288 static int sip24_valid(void) {
    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 	unsigned char in[64];
    356 	struct sipkey k;
    357 	size_t i;
    358 
    359 	sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011"
    360 			"\012\013\014\015\016\017");
    361 
    362 	for (i = 0; i < sizeof in; ++i) {
    363 		in[i] = (unsigned char)i;
    364 
    365 		if (siphash24(in, i, &k) != SIP_U8TO64_LE(vectors[i]))
    366 			return 0;
    367 	}
    368 
    369 	return 1;
    370 } /* sip24_valid() */
    371 
    372 
    373 #ifdef SIPHASH_MAIN
    374 
    375 #include <stdio.h>
    376 
    377 int main(void) {
    378 	const int ok = sip24_valid();
    379 
    380 	if (ok)
    381 		puts("OK");
    382 	else
    383 		puts("FAIL");
    384 
    385 	return !ok;
    386 } /* main() */
    387 
    388 #endif /* SIPHASH_MAIN */
    389 
    390 
    391 #endif /* SIPHASH_H */
    392