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 * 2017-07-25 (Vadim Zeitlin)
15 * - Fix use of SIPHASH_MAIN macro
16 *
17 * 2017-07-05 (Sebastian Pipping)
18 * - Use _SIP_ULL macro to not require a C++11 compiler if compiled as C++
19 * - Add const qualifiers at two places
20 * - Ensure <=80 characters line length (assuming tab width 4)
21 *
22 * 2017-06-23 (Victor Stinner)
23 * - Address Win64 compile warnings
24 *
25 * 2017-06-18 (Sebastian Pipping)
26 * - Clarify license note in the header
27 * - Address C89 issues:
28 * - Stop using inline keyword (and let compiler decide)
29 * - Replace _Bool by int
30 * - Turn macro siphash24 into a function
31 * - Address invalid conversion (void pointer) by explicit cast
32 * - Address lack of stdint.h for Visual Studio 2003 to 2008
33 * - Always expose sip24_valid (for self-tests)
34 *
35 * 2012-11-04 - Born. (William Ahern)
36 * --------------------------------------------------------------------------
37 * USAGE:
38 *
39 * SipHash-2-4 takes as input two 64-bit words as the key, some number of
40 * message bytes, and outputs a 64-bit word as the message digest. This
41 * implementation employs two data structures: a struct sipkey for
42 * representing the key, and a struct siphash for representing the hash
43 * state.
44 *
45 * For converting a 16-byte unsigned char array to a key, use either the
46 * macro sip_keyof or the routine sip_tokey. The former instantiates a
47 * compound literal key, while the latter requires a key object as a
48 * parameter.
49 *
50 * unsigned char secret[16];
51 * arc4random_buf(secret, sizeof secret);
52 * struct sipkey *key = sip_keyof(secret);
53 *
54 * For hashing a message, use either the convenience macro siphash24 or the
55 * routines sip24_init, sip24_update, and sip24_final.
56 *
57 * struct siphash state;
58 * void *msg;
59 * size_t len;
60 * uint64_t hash;
61 *
62 * sip24_init(&state, key);
63 * sip24_update(&state, msg, len);
64 * hash = sip24_final(&state);
65 *
66 * or
67 *
68 * hash = siphash24(msg, len, key);
69 *
70 * To convert the 64-bit hash value to a canonical 8-byte little-endian
71 * binary representation, use either the macro sip_binof or the routine
72 * sip_tobin. The former instantiates and returns a compound literal array,
73 * while the latter requires an array object as a parameter.
74 * --------------------------------------------------------------------------
75 * NOTES:
76 *
77 * o Neither sip_keyof, sip_binof, nor siphash24 will work with compilers
78 * lacking compound literal support. Instead, you must use the lower-level
79 * interfaces which take as parameters the temporary state objects.
80 *
81 * o Uppercase macros may evaluate parameters more than once. Lowercase
82 * macros should not exhibit any such side effects.
83 * ==========================================================================
84 */
85 #ifndef SIPHASH_H
86 #define SIPHASH_H
87
88 #include <stddef.h> /* size_t */
89
90 #if defined(_WIN32) && defined(_MSC_VER) && (_MSC_VER < 1600)
91 /* For vs2003/7.1 up to vs2008/9.0; _MSC_VER 1600 is vs2010/10.0 */
92 typedef unsigned __int8 uint8_t;
93 typedef unsigned __int32 uint32_t;
94 typedef unsigned __int64 uint64_t;
95 #else
96 #include <stdint.h> /* uint64_t uint32_t uint8_t */
97 #endif
98
99
100 /*
101 * Workaround to not require a C++11 compiler for using ULL suffix
102 * if this code is included and compiled as C++; related GCC warning is:
103 * warning: use of C++11 long long integer constant [-Wlong-long]
104 */
105 #define _SIP_ULL(high, low) (((uint64_t)high << 32) | low)
106
107
108 #define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ( (x) >> (64 - (b))))
109
110 #define SIP_U32TO8_LE(p, v) \
111 (p)[0] = (uint8_t)((v) >> 0); (p)[1] = (uint8_t)((v) >> 8); \
112 (p)[2] = (uint8_t)((v) >> 16); (p)[3] = (uint8_t)((v) >> 24);
113
114 #define SIP_U64TO8_LE(p, v) \
115 SIP_U32TO8_LE((p) + 0, (uint32_t)((v) >> 0)); \
116 SIP_U32TO8_LE((p) + 4, (uint32_t)((v) >> 32));
117
118 #define SIP_U8TO64_LE(p) \
119 (((uint64_t)((p)[0]) << 0) | \
120 ((uint64_t)((p)[1]) << 8) | \
121 ((uint64_t)((p)[2]) << 16) | \
122 ((uint64_t)((p)[3]) << 24) | \
123 ((uint64_t)((p)[4]) << 32) | \
124 ((uint64_t)((p)[5]) << 40) | \
125 ((uint64_t)((p)[6]) << 48) | \
126 ((uint64_t)((p)[7]) << 56))
127
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
139 #define SIP_KEYLEN 16
140
141 struct sipkey {
142 uint64_t k[2];
143 }; /* struct sipkey */
144
145 #define sip_keyof(k) sip_tokey(&(struct sipkey){ { 0 } }, (k))
146
sip_tokey(struct sipkey * key,const void * src)147 static struct sipkey *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
154 #define sip_binof(v) sip_tobin((unsigned char[8]){ 0 }, (v))
155
sip_tobin(void * dst,uint64_t u64)156 static void *sip_tobin(void *dst, uint64_t u64) {
157 SIP_U64TO8_LE((unsigned char *)dst, u64);
158 return dst;
159 } /* sip_tobin() */
160
161
sip_round(struct siphash * H,const int rounds)162 static void sip_round(struct siphash *H, const int rounds) {
163 int i;
164
165 for (i = 0; i < rounds; i++) {
166 H->v0 += H->v1;
167 H->v1 = SIP_ROTL(H->v1, 13);
168 H->v1 ^= H->v0;
169 H->v0 = SIP_ROTL(H->v0, 32);
170
171 H->v2 += H->v3;
172 H->v3 = SIP_ROTL(H->v3, 16);
173 H->v3 ^= H->v2;
174
175 H->v0 += H->v3;
176 H->v3 = SIP_ROTL(H->v3, 21);
177 H->v3 ^= H->v0;
178
179 H->v2 += H->v1;
180 H->v1 = SIP_ROTL(H->v1, 17);
181 H->v1 ^= H->v2;
182 H->v2 = SIP_ROTL(H->v2, 32);
183 }
184 } /* sip_round() */
185
186
sip24_init(struct siphash * H,const struct sipkey * key)187 static struct siphash *sip24_init(struct siphash *H,
188 const struct sipkey *key) {
189 H->v0 = _SIP_ULL(0x736f6d65U, 0x70736575U) ^ key->k[0];
190 H->v1 = _SIP_ULL(0x646f7261U, 0x6e646f6dU) ^ key->k[1];
191 H->v2 = _SIP_ULL(0x6c796765U, 0x6e657261U) ^ key->k[0];
192 H->v3 = _SIP_ULL(0x74656462U, 0x79746573U) ^ key->k[1];
193
194 H->p = H->buf;
195 H->c = 0;
196
197 return H;
198 } /* sip24_init() */
199
200
201 #define sip_endof(a) (&(a)[sizeof (a) / sizeof *(a)])
202
sip24_update(struct siphash * H,const void * src,size_t len)203 static struct siphash *sip24_update(struct siphash *H, const void *src,
204 size_t len) {
205 const unsigned char *p = (const unsigned char *)src, *pe = p + len;
206 uint64_t m;
207
208 do {
209 while (p < pe && H->p < sip_endof(H->buf))
210 *H->p++ = *p++;
211
212 if (H->p < sip_endof(H->buf))
213 break;
214
215 m = SIP_U8TO64_LE(H->buf);
216 H->v3 ^= m;
217 sip_round(H, 2);
218 H->v0 ^= m;
219
220 H->p = H->buf;
221 H->c += 8;
222 } while (p < pe);
223
224 return H;
225 } /* sip24_update() */
226
227
sip24_final(struct siphash * H)228 static uint64_t sip24_final(struct siphash *H) {
229 const char left = (char)(H->p - H->buf);
230 uint64_t b = (H->c + left) << 56;
231
232 switch (left) {
233 case 7: b |= (uint64_t)H->buf[6] << 48;
234 case 6: b |= (uint64_t)H->buf[5] << 40;
235 case 5: b |= (uint64_t)H->buf[4] << 32;
236 case 4: b |= (uint64_t)H->buf[3] << 24;
237 case 3: b |= (uint64_t)H->buf[2] << 16;
238 case 2: b |= (uint64_t)H->buf[1] << 8;
239 case 1: b |= (uint64_t)H->buf[0] << 0;
240 case 0: break;
241 }
242
243 H->v3 ^= b;
244 sip_round(H, 2);
245 H->v0 ^= b;
246 H->v2 ^= 0xff;
247 sip_round(H, 4);
248
249 return H->v0 ^ H->v1 ^ H->v2 ^ H->v3;
250 } /* sip24_final() */
251
252
siphash24(const void * src,size_t len,const struct sipkey * key)253 static uint64_t siphash24(const void *src, size_t len,
254 const struct sipkey *key) {
255 struct siphash state = SIPHASH_INITIALIZER;
256 return sip24_final(sip24_update(sip24_init(&state, key), src, len));
257 } /* siphash24() */
258
259
260 /*
261 * SipHash-2-4 output with
262 * k = 00 01 02 ...
263 * and
264 * in = (empty string)
265 * in = 00 (1 byte)
266 * in = 00 01 (2 bytes)
267 * in = 00 01 02 (3 bytes)
268 * ...
269 * in = 00 01 02 ... 3e (63 bytes)
270 */
sip24_valid(void)271 static int sip24_valid(void) {
272 static const unsigned char vectors[64][8] = {
273 { 0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72, },
274 { 0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74, },
275 { 0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d, },
276 { 0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85, },
277 { 0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf, },
278 { 0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18, },
279 { 0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb, },
280 { 0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab, },
281 { 0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93, },
282 { 0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e, },
283 { 0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a, },
284 { 0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4, },
285 { 0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75, },
286 { 0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14, },
287 { 0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7, },
288 { 0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1, },
289 { 0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f, },
290 { 0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69, },
291 { 0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b, },
292 { 0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb, },
293 { 0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe, },
294 { 0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0, },
295 { 0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93, },
296 { 0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8, },
297 { 0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8, },
298 { 0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc, },
299 { 0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17, },
300 { 0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f, },
301 { 0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde, },
302 { 0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6, },
303 { 0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad, },
304 { 0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32, },
305 { 0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71, },
306 { 0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7, },
307 { 0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12, },
308 { 0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15, },
309 { 0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31, },
310 { 0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02, },
311 { 0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca, },
312 { 0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a, },
313 { 0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e, },
314 { 0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad, },
315 { 0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18, },
316 { 0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4, },
317 { 0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9, },
318 { 0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9, },
319 { 0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb, },
320 { 0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0, },
321 { 0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6, },
322 { 0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7, },
323 { 0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee, },
324 { 0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1, },
325 { 0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a, },
326 { 0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81, },
327 { 0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f, },
328 { 0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24, },
329 { 0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7, },
330 { 0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea, },
331 { 0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60, },
332 { 0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66, },
333 { 0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c, },
334 { 0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f, },
335 { 0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5, },
336 { 0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95, }
337 };
338 unsigned char in[64];
339 struct sipkey k;
340 size_t i;
341
342 sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011"
343 "\012\013\014\015\016\017");
344
345 for (i = 0; i < sizeof in; ++i) {
346 in[i] = (unsigned char)i;
347
348 if (siphash24(in, i, &k) != SIP_U8TO64_LE(vectors[i]))
349 return 0;
350 }
351
352 return 1;
353 } /* sip24_valid() */
354
355
356 #ifdef SIPHASH_MAIN
357
358 #include <stdio.h>
359
main(void)360 int main(void) {
361 const int ok = sip24_valid();
362
363 if (ok)
364 puts("OK");
365 else
366 puts("FAIL");
367
368 return !ok;
369 } /* main() */
370
371 #endif /* SIPHASH_MAIN */
372
373
374 #endif /* SIPHASH_H */
375