siphash.h 11 KB

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  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.
  9. *
  10. * 1. https://www.131002.net/siphash/siphash24.c
  11. * 2. https://www.131002.net/siphash/
  12. * --------------------------------------------------------------------------
  13. * HISTORY:
  14. *
  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)
  24. *
  25. * 2012-11-04 - Born. (William Ahern)
  26. * --------------------------------------------------------------------------
  27. * USAGE:
  28. *
  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
  33. * state.
  34. *
  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
  38. * parameter.
  39. *
  40. * unsigned char secret[16];
  41. * arc4random_buf(secret, sizeof secret);
  42. * struct sipkey *key = sip_keyof(secret);
  43. *
  44. * For hashing a message, use either the convenience macro siphash24 or the
  45. * routines sip24_init, sip24_update, and sip24_final.
  46. *
  47. * struct siphash state;
  48. * void *msg;
  49. * size_t len;
  50. * uint64_t hash;
  51. *
  52. * sip24_init(&state, key);
  53. * sip24_update(&state, msg, len);
  54. * hash = sip24_final(&state);
  55. *
  56. * or
  57. *
  58. * hash = siphash24(msg, len, key);
  59. *
  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. * --------------------------------------------------------------------------
  65. * NOTES:
  66. *
  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.
  70. *
  71. * o Uppercase macros may evaluate parameters more than once. Lowercase
  72. * macros should not exhibit any such side effects.
  73. * ==========================================================================
  74. */
  75. #ifndef SIPHASH_H
  76. #define SIPHASH_H
  77. #include <stddef.h> /* size_t */
  78. #include <stdint.h> /* uint64_t uint32_t uint8_t */
  79. #define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ( (x) >> (64 - (b))))
  80. #define SIP_U32TO8_LE(p, v) \
  81. (p)[0] = (uint8_t)((v) >> 0); (p)[1] = (uint8_t)((v) >> 8); \
  82. (p)[2] = (uint8_t)((v) >> 16); (p)[3] = (uint8_t)((v) >> 24);
  83. #define SIP_U64TO8_LE(p, v) \
  84. SIP_U32TO8_LE((p) + 0, (uint32_t)((v) >> 0)); \
  85. SIP_U32TO8_LE((p) + 4, (uint32_t)((v) >> 32));
  86. #define SIP_U8TO64_LE(p) \
  87. (((uint64_t)((p)[0]) << 0) | \
  88. ((uint64_t)((p)[1]) << 8) | \
  89. ((uint64_t)((p)[2]) << 16) | \
  90. ((uint64_t)((p)[3]) << 24) | \
  91. ((uint64_t)((p)[4]) << 32) | \
  92. ((uint64_t)((p)[5]) << 40) | \
  93. ((uint64_t)((p)[6]) << 48) | \
  94. ((uint64_t)((p)[7]) << 56))
  95. #define SIPHASH_INITIALIZER { 0, 0, 0, 0, { 0 }, 0, 0 }
  96. struct siphash {
  97. uint64_t v0, v1, v2, v3;
  98. unsigned char buf[8], *p;
  99. uint64_t c;
  100. }; /* struct siphash */
  101. #define SIP_KEYLEN 16
  102. struct sipkey {
  103. uint64_t k[2];
  104. }; /* struct sipkey */
  105. #define sip_keyof(k) sip_tokey(&(struct sipkey){ { 0 } }, (k))
  106. static struct sipkey *sip_tokey(struct sipkey *key, const void *src) {
  107. key->k[0] = SIP_U8TO64_LE((const unsigned char *)src);
  108. key->k[1] = SIP_U8TO64_LE((const unsigned char *)src + 8);
  109. return key;
  110. } /* sip_tokey() */
  111. #define sip_binof(v) sip_tobin((unsigned char[8]){ 0 }, (v))
  112. static void *sip_tobin(void *dst, uint64_t u64) {
  113. SIP_U64TO8_LE((unsigned char *)dst, u64);
  114. return dst;
  115. } /* sip_tobin() */
  116. static void sip_round(struct siphash *H, const int rounds) {
  117. int i;
  118. for (i = 0; i < rounds; i++) {
  119. H->v0 += H->v1;
  120. H->v1 = SIP_ROTL(H->v1, 13);
  121. H->v1 ^= H->v0;
  122. H->v0 = SIP_ROTL(H->v0, 32);
  123. H->v2 += H->v3;
  124. H->v3 = SIP_ROTL(H->v3, 16);
  125. H->v3 ^= H->v2;
  126. H->v0 += H->v3;
  127. H->v3 = SIP_ROTL(H->v3, 21);
  128. H->v3 ^= H->v0;
  129. H->v2 += H->v1;
  130. H->v1 = SIP_ROTL(H->v1, 17);
  131. H->v1 ^= H->v2;
  132. H->v2 = SIP_ROTL(H->v2, 32);
  133. }
  134. } /* sip_round() */
  135. static struct siphash *sip24_init(struct siphash *H, const struct sipkey *key) {
  136. H->v0 = 0x736f6d6570736575UL ^ key->k[0];
  137. H->v1 = 0x646f72616e646f6dUL ^ key->k[1];
  138. H->v2 = 0x6c7967656e657261UL ^ key->k[0];
  139. H->v3 = 0x7465646279746573UL ^ key->k[1];
  140. H->p = H->buf;
  141. H->c = 0;
  142. return H;
  143. } /* sip24_init() */
  144. #define sip_endof(a) (&(a)[sizeof (a) / sizeof *(a)])
  145. static struct siphash *sip24_update(struct siphash *H, const void *src, size_t len) {
  146. const unsigned char *p = (const unsigned char *)src, *pe = p + len;
  147. uint64_t m;
  148. do {
  149. while (p < pe && H->p < sip_endof(H->buf))
  150. *H->p++ = *p++;
  151. if (H->p < sip_endof(H->buf))
  152. break;
  153. m = SIP_U8TO64_LE(H->buf);
  154. H->v3 ^= m;
  155. sip_round(H, 2);
  156. H->v0 ^= m;
  157. H->p = H->buf;
  158. H->c += 8;
  159. } while (p < pe);
  160. return H;
  161. } /* sip24_update() */
  162. static uint64_t sip24_final(struct siphash *H) {
  163. char left = H->p - H->buf;
  164. uint64_t b = (H->c + left) << 56;
  165. switch (left) {
  166. case 7: b |= (uint64_t)H->buf[6] << 48;
  167. case 6: b |= (uint64_t)H->buf[5] << 40;
  168. case 5: b |= (uint64_t)H->buf[4] << 32;
  169. case 4: b |= (uint64_t)H->buf[3] << 24;
  170. case 3: b |= (uint64_t)H->buf[2] << 16;
  171. case 2: b |= (uint64_t)H->buf[1] << 8;
  172. case 1: b |= (uint64_t)H->buf[0] << 0;
  173. case 0: break;
  174. }
  175. H->v3 ^= b;
  176. sip_round(H, 2);
  177. H->v0 ^= b;
  178. H->v2 ^= 0xff;
  179. sip_round(H, 4);
  180. return H->v0 ^ H->v1 ^ H->v2 ^ H->v3;
  181. } /* sip24_final() */
  182. static uint64_t siphash24(const void *src, size_t len, const struct sipkey *key) {
  183. struct siphash state = SIPHASH_INITIALIZER;
  184. return sip24_final(sip24_update(sip24_init(&state, key), src, len));
  185. } /* siphash24() */
  186. /*
  187. * SipHash-2-4 output with
  188. * k = 00 01 02 ...
  189. * and
  190. * in = (empty string)
  191. * in = 00 (1 byte)
  192. * in = 00 01 (2 bytes)
  193. * in = 00 01 02 (3 bytes)
  194. * ...
  195. * in = 00 01 02 ... 3e (63 bytes)
  196. */
  197. static int sip24_valid(void) {
  198. static const unsigned char vectors[64][8] = {
  199. { 0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72, },
  200. { 0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74, },
  201. { 0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d, },
  202. { 0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85, },
  203. { 0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf, },
  204. { 0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18, },
  205. { 0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb, },
  206. { 0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab, },
  207. { 0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93, },
  208. { 0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e, },
  209. { 0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a, },
  210. { 0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4, },
  211. { 0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75, },
  212. { 0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14, },
  213. { 0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7, },
  214. { 0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1, },
  215. { 0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f, },
  216. { 0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69, },
  217. { 0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b, },
  218. { 0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb, },
  219. { 0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe, },
  220. { 0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0, },
  221. { 0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93, },
  222. { 0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8, },
  223. { 0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8, },
  224. { 0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc, },
  225. { 0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17, },
  226. { 0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f, },
  227. { 0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde, },
  228. { 0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6, },
  229. { 0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad, },
  230. { 0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32, },
  231. { 0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71, },
  232. { 0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7, },
  233. { 0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12, },
  234. { 0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15, },
  235. { 0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31, },
  236. { 0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02, },
  237. { 0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca, },
  238. { 0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a, },
  239. { 0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e, },
  240. { 0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad, },
  241. { 0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18, },
  242. { 0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4, },
  243. { 0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9, },
  244. { 0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9, },
  245. { 0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb, },
  246. { 0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0, },
  247. { 0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6, },
  248. { 0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7, },
  249. { 0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee, },
  250. { 0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1, },
  251. { 0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a, },
  252. { 0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81, },
  253. { 0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f, },
  254. { 0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24, },
  255. { 0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7, },
  256. { 0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea, },
  257. { 0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60, },
  258. { 0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66, },
  259. { 0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c, },
  260. { 0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f, },
  261. { 0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5, },
  262. { 0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95, }
  263. };
  264. unsigned char in[64];
  265. struct sipkey k;
  266. size_t i;
  267. sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017");
  268. for (i = 0; i < sizeof in; ++i) {
  269. in[i] = i;
  270. if (siphash24(in, i, &k) != SIP_U8TO64_LE(vectors[i]))
  271. return 0;
  272. }
  273. return 1;
  274. } /* sip24_valid() */
  275. #if SIPHASH_MAIN
  276. #include <stdio.h>
  277. int main(void) {
  278. int ok = sip24_valid();
  279. if (ok)
  280. puts("OK");
  281. else
  282. puts("FAIL");
  283. return !ok;
  284. } /* main() */
  285. #endif /* SIPHASH_MAIN */
  286. #endif /* SIPHASH_H */