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 * 2019-08-03 (Sebastian Pipping)
15 * - Mark part of sip24_valid as to be excluded from clang-format
16 * - Re-format code using clang-format 9
17 *
18 * 2018-07-08 (Anton Maklakov)
19 * - Add "fall through" markers for GCC's -Wimplicit-fallthrough
20 *
21 * 2017-11-03 (Sebastian Pipping)
22 * - Hide sip_tobin and sip_binof unless SIPHASH_TOBIN macro is defined
23 *
24 * 2017-07-25 (Vadim Zeitlin)
25 * - Fix use of SIPHASH_MAIN macro
26 *
27 * 2017-07-05 (Sebastian Pipping)
28 * - Use _SIP_ULL macro to not require a C++11 compiler if compiled as C++
29 * - Add const qualifiers at two places
30 * - Ensure <=80 characters line length (assuming tab width 4)
31 *
32 * 2017-06-23 (Victor Stinner)
33 * - Address Win64 compile warnings
34 *
35 * 2017-06-18 (Sebastian Pipping)
36 * - Clarify license note in the header
37 * - Address C89 issues:
38 * - Stop using inline keyword (and let compiler decide)
39 * - Replace _Bool by int
40 * - Turn macro siphash24 into a function
41 * - Address invalid conversion (void pointer) by explicit cast
42 * - Address lack of stdint.h for Visual Studio 2003 to 2008
43 * - Always expose sip24_valid (for self-tests)
44 *
45 * 2012-11-04 - Born. (William Ahern)
46 * --------------------------------------------------------------------------
47 * USAGE:
48 *
49 * SipHash-2-4 takes as input two 64-bit words as the key, some number of
50 * message bytes, and outputs a 64-bit word as the message digest. This
51 * implementation employs two data structures: a struct sipkey for
52 * representing the key, and a struct siphash for representing the hash
53 * state.
54 *
55 * For converting a 16-byte unsigned char array to a key, use either the
56 * macro sip_keyof or the routine sip_tokey. The former instantiates a
57 * compound literal key, while the latter requires a key object as a
58 * parameter.
59 *
60 * unsigned char secret[16];
61 * arc4random_buf(secret, sizeof secret);
62 * struct sipkey *key = sip_keyof(secret);
63 *
64 * For hashing a message, use either the convenience macro siphash24 or the
65 * routines sip24_init, sip24_update, and sip24_final.
66 *
67 * struct siphash state;
68 * void *msg;
69 * size_t len;
70 * uint64_t hash;
71 *
72 * sip24_init(&state, key);
73 * sip24_update(&state, msg, len);
74 * hash = sip24_final(&state);
75 *
76 * or
77 *
78 * hash = siphash24(msg, len, key);
79 *
80 * To convert the 64-bit hash value to a canonical 8-byte little-endian
81 * binary representation, use either the macro sip_binof or the routine
82 * sip_tobin. The former instantiates and returns a compound literal array,
83 * while the latter requires an array object as a parameter.
84 * --------------------------------------------------------------------------
85 * NOTES:
86 *
87 * o Neither sip_keyof, sip_binof, nor siphash24 will work with compilers
88 * lacking compound literal support. Instead, you must use the lower-level
89 * interfaces which take as parameters the temporary state objects.
90 *
91 * o Uppercase macros may evaluate parameters more than once. Lowercase
92 * macros should not exhibit any such side effects.
93 * ==========================================================================
94 */
95 #ifndef SIPHASH_H
96 #define SIPHASH_H
97
98 #include <stddef.h> /* size_t */
99
100 #if defined(_WIN32) && defined(_MSC_VER) && (_MSC_VER < 1600)
101 /* For vs2003/7.1 up to vs2008/9.0; _MSC_VER 1600 is vs2010/10.0 */
102 typedef unsigned __int8 uint8_t;
103 typedef unsigned __int32 uint32_t;
104 typedef unsigned __int64 uint64_t;
105 #else
106 # include <stdint.h> /* uint64_t uint32_t uint8_t */
107 #endif
108
109 /*
110 * Workaround to not require a C++11 compiler for using ULL suffix
111 * if this code is included and compiled as C++; related GCC warning is:
112 * warning: use of C++11 long long integer constant [-Wlong-long]
113 */
114 #define _SIP_ULL(high, low) (((uint64_t)high << 32) | low)
115
116 #define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
117
118 #define SIP_U32TO8_LE(p, v) \
119 (p)[0] = (uint8_t)((v) >> 0); \
120 (p)[1] = (uint8_t)((v) >> 8); \
121 (p)[2] = (uint8_t)((v) >> 16); \
122 (p)[3] = (uint8_t)((v) >> 24);
123
124 #define SIP_U64TO8_LE(p, v) \
125 SIP_U32TO8_LE((p) + 0, (uint32_t)((v) >> 0)); \
126 SIP_U32TO8_LE((p) + 4, (uint32_t)((v) >> 32));
127
128 #define SIP_U8TO64_LE(p) \
129 (((uint64_t)((p)[0]) << 0) | ((uint64_t)((p)[1]) << 8) \
130 | ((uint64_t)((p)[2]) << 16) | ((uint64_t)((p)[3]) << 24) \
131 | ((uint64_t)((p)[4]) << 32) | ((uint64_t)((p)[5]) << 40) \
132 | ((uint64_t)((p)[6]) << 48) | ((uint64_t)((p)[7]) << 56))
133
134 #define SIPHASH_INITIALIZER \
135 { 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 #define SIP_KEYLEN 16
145
146 struct sipkey {
147 uint64_t k[2];
148 }; /* struct sipkey */
149
150 #define sip_keyof(k) sip_tokey(&(struct sipkey){{0}}, (k))
151
152 static struct sipkey *
sip_tokey(struct sipkey * key,const void * src)153 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 #ifdef SIPHASH_TOBIN
160
161 # define sip_binof(v) sip_tobin((unsigned char[8]){0}, (v))
162
163 static void *
sip_tobin(void * dst,uint64_t u64)164 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 static void
sip_round(struct siphash * H,const int rounds)172 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 static struct siphash *
sip24_init(struct siphash * H,const struct sipkey * key)197 sip24_init(struct siphash *H, const struct sipkey *key) {
198 H->v0 = _SIP_ULL(0x736f6d65U, 0x70736575U) ^ key->k[0];
199 H->v1 = _SIP_ULL(0x646f7261U, 0x6e646f6dU) ^ key->k[1];
200 H->v2 = _SIP_ULL(0x6c796765U, 0x6e657261U) ^ key->k[0];
201 H->v3 = _SIP_ULL(0x74656462U, 0x79746573U) ^ key->k[1];
202
203 H->p = H->buf;
204 H->c = 0;
205
206 return H;
207 } /* sip24_init() */
208
209 #define sip_endof(a) (&(a)[sizeof(a) / sizeof *(a)])
210
211 static struct siphash *
sip24_update(struct siphash * H,const void * src,size_t len)212 sip24_update(struct siphash *H, const void *src, size_t len) {
213 const unsigned char *p = (const unsigned char *)src, *pe = p + len;
214 uint64_t m;
215
216 do {
217 while (p < pe && H->p < sip_endof(H->buf))
218 *H->p++ = *p++;
219
220 if (H->p < sip_endof(H->buf))
221 break;
222
223 m = SIP_U8TO64_LE(H->buf);
224 H->v3 ^= m;
225 sip_round(H, 2);
226 H->v0 ^= m;
227
228 H->p = H->buf;
229 H->c += 8;
230 } while (p < pe);
231
232 return H;
233 } /* sip24_update() */
234
235 static uint64_t
sip24_final(struct siphash * H)236 sip24_final(struct siphash *H) {
237 const char left = (char)(H->p - H->buf);
238 uint64_t b = (H->c + left) << 56;
239
240 switch (left) {
241 case 7:
242 b |= (uint64_t)H->buf[6] << 48;
243 /* fall through */
244 case 6:
245 b |= (uint64_t)H->buf[5] << 40;
246 /* fall through */
247 case 5:
248 b |= (uint64_t)H->buf[4] << 32;
249 /* fall through */
250 case 4:
251 b |= (uint64_t)H->buf[3] << 24;
252 /* fall through */
253 case 3:
254 b |= (uint64_t)H->buf[2] << 16;
255 /* fall through */
256 case 2:
257 b |= (uint64_t)H->buf[1] << 8;
258 /* fall through */
259 case 1:
260 b |= (uint64_t)H->buf[0] << 0;
261 /* fall through */
262 case 0:
263 break;
264 }
265
266 H->v3 ^= b;
267 sip_round(H, 2);
268 H->v0 ^= b;
269 H->v2 ^= 0xff;
270 sip_round(H, 4);
271
272 return H->v0 ^ H->v1 ^ H->v2 ^ H->v3;
273 } /* sip24_final() */
274
275 static uint64_t
siphash24(const void * src,size_t len,const struct sipkey * key)276 siphash24(const void *src, size_t len, const struct sipkey *key) {
277 struct siphash state = SIPHASH_INITIALIZER;
278 return sip24_final(sip24_update(sip24_init(&state, key), src, len));
279 } /* siphash24() */
280
281 /*
282 * SipHash-2-4 output with
283 * k = 00 01 02 ...
284 * and
285 * in = (empty string)
286 * in = 00 (1 byte)
287 * in = 00 01 (2 bytes)
288 * in = 00 01 02 (3 bytes)
289 * ...
290 * in = 00 01 02 ... 3e (63 bytes)
291 */
292 static int
sip24_valid(void)293 sip24_valid(void) {
294 /* clang-format off */
295 static const unsigned char vectors[64][8] = {
296 { 0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72, },
297 { 0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74, },
298 { 0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d, },
299 { 0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85, },
300 { 0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf, },
301 { 0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18, },
302 { 0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb, },
303 { 0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab, },
304 { 0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93, },
305 { 0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e, },
306 { 0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a, },
307 { 0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4, },
308 { 0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75, },
309 { 0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14, },
310 { 0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7, },
311 { 0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1, },
312 { 0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f, },
313 { 0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69, },
314 { 0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b, },
315 { 0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb, },
316 { 0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe, },
317 { 0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0, },
318 { 0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93, },
319 { 0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8, },
320 { 0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8, },
321 { 0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc, },
322 { 0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17, },
323 { 0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f, },
324 { 0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde, },
325 { 0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6, },
326 { 0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad, },
327 { 0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32, },
328 { 0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71, },
329 { 0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7, },
330 { 0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12, },
331 { 0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15, },
332 { 0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31, },
333 { 0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02, },
334 { 0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca, },
335 { 0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a, },
336 { 0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e, },
337 { 0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad, },
338 { 0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18, },
339 { 0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4, },
340 { 0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9, },
341 { 0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9, },
342 { 0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb, },
343 { 0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0, },
344 { 0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6, },
345 { 0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7, },
346 { 0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee, },
347 { 0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1, },
348 { 0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a, },
349 { 0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81, },
350 { 0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f, },
351 { 0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24, },
352 { 0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7, },
353 { 0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea, },
354 { 0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60, },
355 { 0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66, },
356 { 0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c, },
357 { 0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f, },
358 { 0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5, },
359 { 0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95, }
360 };
361 /* clang-format on */
362
363 unsigned char in[64];
364 struct sipkey k;
365 size_t i;
366
367 sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011"
368 "\012\013\014\015\016\017");
369
370 for (i = 0; i < sizeof in; ++i) {
371 in[i] = (unsigned char)i;
372
373 if (siphash24(in, i, &k) != SIP_U8TO64_LE(vectors[i]))
374 return 0;
375 }
376
377 return 1;
378 } /* sip24_valid() */
379
380 #ifdef SIPHASH_MAIN
381
382 # include <stdio.h>
383
384 int
main(void)385 main(void) {
386 const int ok = sip24_valid();
387
388 if (ok)
389 puts("OK");
390 else
391 puts("FAIL");
392
393 return ! ok;
394 } /* main() */
395
396 #endif /* SIPHASH_MAIN */
397
398 #endif /* SIPHASH_H */
399