xref: /freebsd/contrib/expat/lib/siphash.h (revision cddbc3b40812213ff00041f79174cac0be360a2a)
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