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 * by Jean-Philippe Aumasson and Daniel J. Berstein.
7 * Minimal changes by Sebastian Pipping on top, details below.
8 * Licensed under the CC0 Public Domain Dedication license.
10 * 1. https://www.131002.net/siphash/siphash24.c
11 * 2. https://www.131002.net/siphash/
12 * --------------------------------------------------------------------------
15 * 2017-06-10 (Sebastian Pipping)
16 * - Clarify license note in the header
17 * - Address C89 issues:
18 * - Stop using inline keyword (and let compiler decide)
19 * - Turn integer suffix ULL to UL
20 * - Replace _Bool by int
21 * - Turn macro siphash24 into a function
22 * - Address invalid conversion (void pointer) by explicit cast
23 * - Always expose sip24_valid (for self-tests)
25 * 2012-11-04 - Born. (William Ahern)
26 * --------------------------------------------------------------------------
29 * SipHash-2-4 takes as input two 64-bit words as the key, some number of
30 * message bytes, and outputs a 64-bit word as the message digest. This
31 * implementation employs two data structures: a struct sipkey for
32 * representing the key, and a struct siphash for representing the hash
35 * For converting a 16-byte unsigned char array to a key, use either the
36 * macro sip_keyof or the routine sip_tokey. The former instantiates a
37 * compound literal key, while the latter requires a key object as a
40 * unsigned char secret[16];
41 * arc4random_buf(secret, sizeof secret);
42 * struct sipkey *key = sip_keyof(secret);
44 * For hashing a message, use either the convenience macro siphash24 or the
45 * routines sip24_init, sip24_update, and sip24_final.
47 * struct siphash state;
52 * sip24_init(&state, key);
53 * sip24_update(&state, msg, len);
54 * hash = sip24_final(&state);
58 * hash = siphash24(msg, len, key);
60 * To convert the 64-bit hash value to a canonical 8-byte little-endian
61 * binary representation, use either the macro sip_binof or the routine
62 * sip_tobin. The former instantiates and returns a compound literal array,
63 * while the latter requires an array object as a parameter.
64 * --------------------------------------------------------------------------
67 * o Neither sip_keyof, sip_binof, nor siphash24 will work with compilers
68 * lacking compound literal support. Instead, you must use the lower-level
69 * interfaces which take as parameters the temporary state objects.
71 * o Uppercase macros may evaluate parameters more than once. Lowercase
72 * macros should not exhibit any such side effects.
73 * ==========================================================================
78 #include <stddef.h> /* size_t */
79 #include <stdint.h> /* uint64_t uint32_t uint8_t */
82 #define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ( (x) >> (64 - (b))))
84 #define SIP_U32TO8_LE(p, v) \
85 (p)[0] = (uint8_t)((v) >> 0); (p)[1] = (uint8_t)((v) >> 8); \
86 (p)[2] = (uint8_t)((v) >> 16); (p)[3] = (uint8_t)((v) >> 24);
88 #define SIP_U64TO8_LE(p, v) \
89 SIP_U32TO8_LE((p) + 0, (uint32_t)((v) >> 0)); \
90 SIP_U32TO8_LE((p) + 4, (uint32_t)((v) >> 32));
92 #define SIP_U8TO64_LE(p) \
93 (((uint64_t)((p)[0]) << 0) | \
94 ((uint64_t)((p)[1]) << 8) | \
95 ((uint64_t)((p)[2]) << 16) | \
96 ((uint64_t)((p)[3]) << 24) | \
97 ((uint64_t)((p)[4]) << 32) | \
98 ((uint64_t)((p)[5]) << 40) | \
99 ((uint64_t)((p)[6]) << 48) | \
100 ((uint64_t)((p)[7]) << 56))
103 #define SIPHASH_INITIALIZER { 0, 0, 0, 0, { 0 }, 0, 0 }
106 uint64_t v0, v1, v2, v3;
108 unsigned char buf[8], *p;
110 }; /* struct siphash */
113 #define SIP_KEYLEN 16
117 }; /* struct sipkey */
119 #define sip_keyof(k) sip_tokey(&(struct sipkey){ { 0 } }, (k))
121 static struct sipkey *sip_tokey(struct sipkey *key, const void *src) {
122 key->k[0] = SIP_U8TO64_LE((const unsigned char *)src);
123 key->k[1] = SIP_U8TO64_LE((const unsigned char *)src + 8);
128 #define sip_binof(v) sip_tobin((unsigned char[8]){ 0 }, (v))
130 static void *sip_tobin(void *dst, uint64_t u64) {
131 SIP_U64TO8_LE((unsigned char *)dst, u64);
136 static void sip_round(struct siphash *H, const int rounds) {
139 for (i = 0; i < rounds; i++) {
141 H->v1 = SIP_ROTL(H->v1, 13);
143 H->v0 = SIP_ROTL(H->v0, 32);
146 H->v3 = SIP_ROTL(H->v3, 16);
150 H->v3 = SIP_ROTL(H->v3, 21);
154 H->v1 = SIP_ROTL(H->v1, 17);
156 H->v2 = SIP_ROTL(H->v2, 32);
161 static struct siphash *sip24_init(struct siphash *H, const struct sipkey *key) {
162 H->v0 = 0x736f6d6570736575UL ^ key->k[0];
163 H->v1 = 0x646f72616e646f6dUL ^ key->k[1];
164 H->v2 = 0x6c7967656e657261UL ^ key->k[0];
165 H->v3 = 0x7465646279746573UL ^ key->k[1];
174 #define sip_endof(a) (&(a)[sizeof (a) / sizeof *(a)])
176 static struct siphash *sip24_update(struct siphash *H, const void *src, size_t len) {
177 const unsigned char *p = (const unsigned char *)src, *pe = p + len;
181 while (p < pe && H->p < sip_endof(H->buf))
184 if (H->p < sip_endof(H->buf))
187 m = SIP_U8TO64_LE(H->buf);
197 } /* sip24_update() */
200 static uint64_t sip24_final(struct siphash *H) {
201 char left = H->p - H->buf;
202 uint64_t b = (H->c + left) << 56;
205 case 7: b |= (uint64_t)H->buf[6] << 48;
206 case 6: b |= (uint64_t)H->buf[5] << 40;
207 case 5: b |= (uint64_t)H->buf[4] << 32;
208 case 4: b |= (uint64_t)H->buf[3] << 24;
209 case 3: b |= (uint64_t)H->buf[2] << 16;
210 case 2: b |= (uint64_t)H->buf[1] << 8;
211 case 1: b |= (uint64_t)H->buf[0] << 0;
221 return H->v0 ^ H->v1 ^ H->v2 ^ H->v3;
222 } /* sip24_final() */
225 static uint64_t siphash24(const void *src, size_t len, const struct sipkey *key) {
226 struct siphash state = SIPHASH_INITIALIZER;
227 return sip24_final(sip24_update(sip24_init(&state, key), src, len));
232 * SipHash-2-4 output with
235 * in = (empty string)
237 * in = 00 01 (2 bytes)
238 * in = 00 01 02 (3 bytes)
240 * in = 00 01 02 ... 3e (63 bytes)
242 static int sip24_valid(void) {
243 static const unsigned char vectors[64][8] = {
244 { 0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72, },
245 { 0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74, },
246 { 0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d, },
247 { 0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85, },
248 { 0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf, },
249 { 0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18, },
250 { 0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb, },
251 { 0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab, },
252 { 0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93, },
253 { 0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e, },
254 { 0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a, },
255 { 0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4, },
256 { 0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75, },
257 { 0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14, },
258 { 0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7, },
259 { 0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1, },
260 { 0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f, },
261 { 0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69, },
262 { 0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b, },
263 { 0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb, },
264 { 0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe, },
265 { 0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0, },
266 { 0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93, },
267 { 0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8, },
268 { 0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8, },
269 { 0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc, },
270 { 0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17, },
271 { 0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f, },
272 { 0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde, },
273 { 0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6, },
274 { 0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad, },
275 { 0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32, },
276 { 0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71, },
277 { 0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7, },
278 { 0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12, },
279 { 0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15, },
280 { 0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31, },
281 { 0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02, },
282 { 0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca, },
283 { 0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a, },
284 { 0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e, },
285 { 0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad, },
286 { 0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18, },
287 { 0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4, },
288 { 0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9, },
289 { 0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9, },
290 { 0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb, },
291 { 0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0, },
292 { 0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6, },
293 { 0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7, },
294 { 0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee, },
295 { 0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1, },
296 { 0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a, },
297 { 0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81, },
298 { 0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f, },
299 { 0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24, },
300 { 0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7, },
301 { 0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea, },
302 { 0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60, },
303 { 0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66, },
304 { 0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c, },
305 { 0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f, },
306 { 0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5, },
307 { 0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95, }
309 unsigned char in[64];
313 sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017");
315 for (i = 0; i < sizeof in; ++i) {
318 if (siphash24(in, i, &k) != SIP_U8TO64_LE(vectors[i]))
323 } /* sip24_valid() */
331 int ok = sip24_valid();
341 #endif /* SIPHASH_MAIN */
344 #endif /* SIPHASH_H */