Line data Source code
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 : *
7 : * 1. https://www.131002.net/siphash/siphash24.c
8 : * 2. https://www.131002.net/siphash/
9 : * --------------------------------------------------------------------------
10 : * HISTORY:
11 : *
12 : * 2012-11-04 - Born.
13 : * --------------------------------------------------------------------------
14 : * USAGE:
15 : *
16 : * SipHash-2-4 takes as input two 64-bit words as the key, some number of
17 : * message bytes, and outputs a 64-bit word as the message digest. This
18 : * implementation employs two data structures: a struct sipkey for
19 : * representing the key, and a struct siphash for representing the hash
20 : * state.
21 : *
22 : * For converting a 16-byte unsigned char array to a key, use either the
23 : * macro sip_keyof or the routine sip_tokey. The former instantiates a
24 : * compound literal key, while the latter requires a key object as a
25 : * parameter.
26 : *
27 : * unsigned char secret[16];
28 : * arc4random_buf(secret, sizeof secret);
29 : * struct sipkey *key = sip_keyof(secret);
30 : *
31 : * For hashing a message, use either the convenience macro siphash24 or the
32 : * routines sip24_init, sip24_update, and sip24_final.
33 : *
34 : * struct siphash state;
35 : * void *msg;
36 : * size_t len;
37 : * uint64_t hash;
38 : *
39 : * sip24_init(&state, key);
40 : * sip24_update(&state, msg, len);
41 : * hash = sip24_final(&state);
42 : *
43 : * or
44 : *
45 : * hash = siphash24(msg, len, key);
46 : *
47 : * To convert the 64-bit hash value to a canonical 8-byte little-endian
48 : * binary representation, use either the macro sip_binof or the routine
49 : * sip_tobin. The former instantiates and returns a compound literal array,
50 : * while the latter requires an array object as a parameter.
51 : * --------------------------------------------------------------------------
52 : * NOTES:
53 : *
54 : * o Neither sip_keyof, sip_binof, nor siphash24 will work with compilers
55 : * lacking compound literal support. Instead, you must use the lower-level
56 : * interfaces which take as parameters the temporary state objects.
57 : *
58 : * o Uppercase macros may evaluate parameters more than once. Lowercase
59 : * macros should not exhibit any such side effects.
60 : * ==========================================================================
61 : */
62 : #ifndef SIPHASH_H
63 : #define SIPHASH_H
64 :
65 : #include <stddef.h> /* size_t */
66 : #include <stdint.h> /* uint64_t uint32_t uint8_t */
67 :
68 :
69 : #define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ( (x) >> (64 - (b))))
70 :
71 : #define SIP_U32TO8_LE(p, v) \
72 : (p)[0] = (uint8_t)((v) >> 0); (p)[1] = (uint8_t)((v) >> 8); \
73 : (p)[2] = (uint8_t)((v) >> 16); (p)[3] = (uint8_t)((v) >> 24);
74 :
75 : #define SIP_U64TO8_LE(p, v) \
76 : SIP_U32TO8_LE((p) + 0, (uint32_t)((v) >> 0)); \
77 : SIP_U32TO8_LE((p) + 4, (uint32_t)((v) >> 32));
78 :
79 : #define SIP_U8TO64_LE(p) \
80 : (((uint64_t)((p)[0]) << 0) | \
81 : ((uint64_t)((p)[1]) << 8) | \
82 : ((uint64_t)((p)[2]) << 16) | \
83 : ((uint64_t)((p)[3]) << 24) | \
84 : ((uint64_t)((p)[4]) << 32) | \
85 : ((uint64_t)((p)[5]) << 40) | \
86 : ((uint64_t)((p)[6]) << 48) | \
87 : ((uint64_t)((p)[7]) << 56))
88 :
89 :
90 : #define SIPHASH_INITIALIZER { 0, 0, 0, 0, { 0 }, 0, 0 }
91 :
92 : struct siphash {
93 : uint64_t v0, v1, v2, v3;
94 :
95 : unsigned char buf[8], *p;
96 : uint64_t c;
97 : }; /* struct siphash */
98 :
99 :
100 : #define SIP_KEYLEN 16
101 :
102 : struct sipkey {
103 : uint64_t k[2];
104 : }; /* struct sipkey */
105 :
106 : #define sip_keyof(k) sip_tokey(&(struct sipkey){ { 0 } }, (k))
107 :
108 : static inline struct sipkey *sip_tokey(struct sipkey *key, const void *src) {
109 : key->k[0] = SIP_U8TO64_LE((const unsigned char *)src);
110 : key->k[1] = SIP_U8TO64_LE((const unsigned char *)src + 8);
111 : return key;
112 : } /* sip_tokey() */
113 :
114 :
115 : #define sip_binof(v) sip_tobin((unsigned char[8]){ 0 }, (v))
116 :
117 : static inline void *sip_tobin(void *dst, uint64_t u64) {
118 : SIP_U64TO8_LE((unsigned char *)dst, u64);
119 : return dst;
120 : } /* sip_tobin() */
121 :
122 :
123 203 : static inline void sip_round(struct siphash *H, const int rounds) {
124 : int i;
125 :
126 671 : for (i = 0; i < rounds; i++) {
127 468 : H->v0 += H->v1;
128 468 : H->v1 = SIP_ROTL(H->v1, 13);
129 468 : H->v1 ^= H->v0;
130 468 : H->v0 = SIP_ROTL(H->v0, 32);
131 :
132 468 : H->v2 += H->v3;
133 468 : H->v3 = SIP_ROTL(H->v3, 16);
134 468 : H->v3 ^= H->v2;
135 :
136 468 : H->v0 += H->v3;
137 468 : H->v3 = SIP_ROTL(H->v3, 21);
138 468 : H->v3 ^= H->v0;
139 :
140 468 : H->v2 += H->v1;
141 468 : H->v1 = SIP_ROTL(H->v1, 17);
142 468 : H->v1 ^= H->v2;
143 468 : H->v2 = SIP_ROTL(H->v2, 32);
144 : }
145 203 : } /* sip_round() */
146 :
147 :
148 31 : static inline struct siphash *sip24_init(struct siphash *H, const struct sipkey *key) {
149 31 : H->v0 = 0x736f6d6570736575ULL ^ key->k[0];
150 31 : H->v1 = 0x646f72616e646f6dULL ^ key->k[1];
151 31 : H->v2 = 0x6c7967656e657261ULL ^ key->k[0];
152 31 : H->v3 = 0x7465646279746573ULL ^ key->k[1];
153 :
154 31 : H->p = H->buf;
155 31 : H->c = 0;
156 :
157 31 : return H;
158 : } /* sip24_init() */
159 :
160 :
161 : #define sip_endof(a) (&(a)[sizeof (a) / sizeof *(a)])
162 :
163 31 : static inline struct siphash *sip24_update(struct siphash *H, const void *src, size_t len) {
164 31 : const unsigned char *p = src, *pe = p + len;
165 : uint64_t m;
166 :
167 : do {
168 1585 : while (p < pe && H->p < sip_endof(H->buf))
169 1247 : *H->p++ = *p++;
170 :
171 169 : if (H->p < sip_endof(H->buf))
172 28 : break;
173 :
174 141 : m = SIP_U8TO64_LE(H->buf);
175 141 : H->v3 ^= m;
176 141 : sip_round(H, 2);
177 141 : H->v0 ^= m;
178 :
179 141 : H->p = H->buf;
180 141 : H->c += 8;
181 141 : } while (p < pe);
182 :
183 31 : return H;
184 : } /* sip24_update() */
185 :
186 :
187 31 : static inline uint64_t sip24_final(struct siphash *H) {
188 31 : char left = H->p - H->buf;
189 31 : uint64_t b = (H->c + left) << 56;
190 :
191 31 : switch (left) {
192 6 : case 7: b |= (uint64_t)H->buf[6] << 48;
193 10 : case 6: b |= (uint64_t)H->buf[5] << 40;
194 18 : case 5: b |= (uint64_t)H->buf[4] << 32;
195 18 : case 4: b |= (uint64_t)H->buf[3] << 24;
196 18 : case 3: b |= (uint64_t)H->buf[2] << 16;
197 21 : case 2: b |= (uint64_t)H->buf[1] << 8;
198 28 : case 1: b |= (uint64_t)H->buf[0] << 0;
199 31 : case 0: break;
200 : }
201 :
202 31 : H->v3 ^= b;
203 31 : sip_round(H, 2);
204 31 : H->v0 ^= b;
205 31 : H->v2 ^= 0xff;
206 31 : sip_round(H, 4);
207 :
208 31 : return H->v0 ^ H->v1 ^ H->v2 ^ H->v3;
209 : } /* sip24_final() */
210 :
211 :
212 : #define siphash24(src, len, key) \
213 : sip24_final(sip24_update(sip24_init(&(struct siphash)SIPHASH_INITIALIZER, (key)), (src), (len)))
214 :
215 :
216 : #if SIPHASH_MAIN
217 :
218 : /*
219 : * SipHash-2-4 output with
220 : * k = 00 01 02 ...
221 : * and
222 : * in = (empty string)
223 : * in = 00 (1 byte)
224 : * in = 00 01 (2 bytes)
225 : * in = 00 01 02 (3 bytes)
226 : * ...
227 : * in = 00 01 02 ... 3e (63 bytes)
228 : */
229 : static inline _Bool sip24_valid(void) {
230 : static const unsigned char vectors[64][8] = {
231 : { 0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72, },
232 : { 0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74, },
233 : { 0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d, },
234 : { 0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85, },
235 : { 0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf, },
236 : { 0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18, },
237 : { 0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb, },
238 : { 0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab, },
239 : { 0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93, },
240 : { 0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e, },
241 : { 0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a, },
242 : { 0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4, },
243 : { 0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75, },
244 : { 0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14, },
245 : { 0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7, },
246 : { 0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1, },
247 : { 0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f, },
248 : { 0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69, },
249 : { 0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b, },
250 : { 0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb, },
251 : { 0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe, },
252 : { 0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0, },
253 : { 0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93, },
254 : { 0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8, },
255 : { 0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8, },
256 : { 0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc, },
257 : { 0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17, },
258 : { 0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f, },
259 : { 0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde, },
260 : { 0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6, },
261 : { 0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad, },
262 : { 0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32, },
263 : { 0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71, },
264 : { 0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7, },
265 : { 0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12, },
266 : { 0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15, },
267 : { 0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31, },
268 : { 0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02, },
269 : { 0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca, },
270 : { 0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a, },
271 : { 0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e, },
272 : { 0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad, },
273 : { 0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18, },
274 : { 0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4, },
275 : { 0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9, },
276 : { 0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9, },
277 : { 0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb, },
278 : { 0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0, },
279 : { 0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6, },
280 : { 0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7, },
281 : { 0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee, },
282 : { 0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1, },
283 : { 0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a, },
284 : { 0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81, },
285 : { 0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f, },
286 : { 0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24, },
287 : { 0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7, },
288 : { 0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea, },
289 : { 0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60, },
290 : { 0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66, },
291 : { 0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c, },
292 : { 0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f, },
293 : { 0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5, },
294 : { 0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95, }
295 : };
296 : unsigned char in[64];
297 : struct sipkey k;
298 : size_t i;
299 :
300 : sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017");
301 :
302 : for (i = 0; i < sizeof in; ++i) {
303 : in[i] = i;
304 :
305 : if (siphash24(in, i, &k) != SIP_U8TO64_LE(vectors[i]))
306 : return 0;
307 : }
308 :
309 : return 1;
310 : } /* sip24_valid() */
311 :
312 :
313 : #include <stdio.h>
314 :
315 : int main(void) {
316 : _Bool ok = sip24_valid();
317 :
318 : if (ok)
319 : puts("OK");
320 : else
321 : puts("FAIL");
322 :
323 : return !ok;
324 : } /* main() */
325 :
326 : #endif /* SIPHASH_MAIN */
327 :
328 :
329 : #endif /* SIPHASH_H */
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