path: root/contrib/libs/expat/lib/siphash.h

/* ========================================================================== 
 * siphash.h - SipHash-2-4 in a single header file 
 * -------------------------------------------------------------------------- 
 * Derived by William Ahern from the reference implementation[1] published[2] 
 * by Jean-Philippe Aumasson and Daniel J. Berstein. 
 * Minimal changes by Sebastian Pipping and Victor Stinner on top, see below. 
 * Licensed under the CC0 Public Domain Dedication license. 
 * 
 * 1. https://www.131002.net/siphash/siphash24.c 
 * 2. https://www.131002.net/siphash/ 
 * -------------------------------------------------------------------------- 
 * HISTORY: 
 * 
 * 2020-10-03  (Sebastian Pipping)
 *   - Drop support for Visual Studio 9.0/2008 and earlier
 *
 * 2019-08-03  (Sebastian Pipping) 
 *   - Mark part of sip24_valid as to be excluded from clang-format 
 *   - Re-format code using clang-format 9 
 * 
 * 2018-07-08  (Anton Maklakov) 
 *   - Add "fall through" markers for GCC's -Wimplicit-fallthrough 
 * 
 * 2017-11-03  (Sebastian Pipping) 
 *   - Hide sip_tobin and sip_binof unless SIPHASH_TOBIN macro is defined 
 * 
 * 2017-07-25  (Vadim Zeitlin) 
 *   - Fix use of SIPHASH_MAIN macro 
 * 
 * 2017-07-05  (Sebastian Pipping) 
 *   - Use _SIP_ULL macro to not require a C++11 compiler if compiled as C++ 
 *   - Add const qualifiers at two places 
 *   - Ensure <=80 characters line length (assuming tab width 4) 
 * 
 * 2017-06-23  (Victor Stinner) 
 *   - Address Win64 compile warnings 
 * 
 * 2017-06-18  (Sebastian Pipping) 
 *   - Clarify license note in the header 
 *   - Address C89 issues: 
 *     - Stop using inline keyword (and let compiler decide) 
 *     - Replace _Bool by int 
 *     - Turn macro siphash24 into a function 
 *     - Address invalid conversion (void pointer) by explicit cast 
 *   - Address lack of stdint.h for Visual Studio 2003 to 2008 
 *   - Always expose sip24_valid (for self-tests) 
 * 
 * 2012-11-04 - Born.  (William Ahern) 
 * -------------------------------------------------------------------------- 
 * USAGE: 
 * 
 * SipHash-2-4 takes as input two 64-bit words as the key, some number of 
 * message bytes, and outputs a 64-bit word as the message digest. This 
 * implementation employs two data structures: a struct sipkey for 
 * representing the key, and a struct siphash for representing the hash 
 * state. 
 * 
 * For converting a 16-byte unsigned char array to a key, use either the 
 * macro sip_keyof or the routine sip_tokey. The former instantiates a 
 * compound literal key, while the latter requires a key object as a 
 * parameter. 
 * 
 * 	unsigned char secret[16]; 
 * 	arc4random_buf(secret, sizeof secret); 
 * 	struct sipkey *key = sip_keyof(secret); 
 * 
 * For hashing a message, use either the convenience macro siphash24 or the 
 * routines sip24_init, sip24_update, and sip24_final. 
 * 
 * 	struct siphash state; 
 * 	void *msg; 
 * 	size_t len; 
 * 	uint64_t hash; 
 * 
 * 	sip24_init(&state, key); 
 * 	sip24_update(&state, msg, len); 
 * 	hash = sip24_final(&state); 
 * 
 * or 
 * 
 * 	hash = siphash24(msg, len, key); 
 * 
 * To convert the 64-bit hash value to a canonical 8-byte little-endian 
 * binary representation, use either the macro sip_binof or the routine 
 * sip_tobin. The former instantiates and returns a compound literal array, 
 * while the latter requires an array object as a parameter. 
 * -------------------------------------------------------------------------- 
 * NOTES: 
 * 
 * o Neither sip_keyof, sip_binof, nor siphash24 will work with compilers 
 *   lacking compound literal support. Instead, you must use the lower-level 
 *   interfaces which take as parameters the temporary state objects. 
 * 
 * o Uppercase macros may evaluate parameters more than once. Lowercase 
 *   macros should not exhibit any such side effects. 
 * ========================================================================== 
 */ 
#ifndef SIPHASH_H 
#define SIPHASH_H 
 
#include <stddef.h> /* size_t */ 
#include <stdint.h> /* uint64_t uint32_t uint8_t */
 
/* 
 * Workaround to not require a C++11 compiler for using ULL suffix 
 * if this code is included and compiled as C++; related GCC warning is: 
 * warning: use of C++11 long long integer constant [-Wlong-long] 
 */ 
#define _SIP_ULL(high, low) (((uint64_t)high << 32) | low) 
 
#define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b)))) 
 
#define SIP_U32TO8_LE(p, v)                                                    \ 
  (p)[0] = (uint8_t)((v) >> 0);                                                \ 
  (p)[1] = (uint8_t)((v) >> 8);                                                \ 
  (p)[2] = (uint8_t)((v) >> 16);                                               \ 
  (p)[3] = (uint8_t)((v) >> 24); 
 
#define SIP_U64TO8_LE(p, v)                                                    \ 
  SIP_U32TO8_LE((p) + 0, (uint32_t)((v) >> 0));                                \ 
  SIP_U32TO8_LE((p) + 4, (uint32_t)((v) >> 32)); 
 
#define SIP_U8TO64_LE(p)                                                       \ 
  (((uint64_t)((p)[0]) << 0) | ((uint64_t)((p)[1]) << 8)                       \ 
   | ((uint64_t)((p)[2]) << 16) | ((uint64_t)((p)[3]) << 24)                   \ 
   | ((uint64_t)((p)[4]) << 32) | ((uint64_t)((p)[5]) << 40)                   \ 
   | ((uint64_t)((p)[6]) << 48) | ((uint64_t)((p)[7]) << 56)) 
 
#define SIPHASH_INITIALIZER                                                    \ 
  { 0, 0, 0, 0, {0}, 0, 0 } 
 
struct siphash { 
  uint64_t v0, v1, v2, v3; 
 
  unsigned char buf[8], *p; 
  uint64_t c; 
}; /* struct siphash */ 
 
#define SIP_KEYLEN 16 
 
struct sipkey { 
  uint64_t k[2]; 
}; /* struct sipkey */ 
 
#define sip_keyof(k) sip_tokey(&(struct sipkey){{0}}, (k)) 
 
static struct sipkey * 
sip_tokey(struct sipkey *key, const void *src) { 
  key->k[0] = SIP_U8TO64_LE((const unsigned char *)src); 
  key->k[1] = SIP_U8TO64_LE((const unsigned char *)src + 8); 
  return key; 
} /* sip_tokey() */ 
 
#ifdef SIPHASH_TOBIN 
 
#  define sip_binof(v) sip_tobin((unsigned char[8]){0}, (v)) 
 
static void * 
sip_tobin(void *dst, uint64_t u64) { 
  SIP_U64TO8_LE((unsigned char *)dst, u64); 
  return dst; 
} /* sip_tobin() */ 
 
#endif /* SIPHASH_TOBIN */ 
 
static void 
sip_round(struct siphash *H, const int rounds) { 
  int i; 
 
  for (i = 0; i < rounds; i++) { 
    H->v0 += H->v1; 
    H->v1 = SIP_ROTL(H->v1, 13); 
    H->v1 ^= H->v0; 
    H->v0 = SIP_ROTL(H->v0, 32); 
 
    H->v2 += H->v3; 
    H->v3 = SIP_ROTL(H->v3, 16); 
    H->v3 ^= H->v2; 
 
    H->v0 += H->v3; 
    H->v3 = SIP_ROTL(H->v3, 21); 
    H->v3 ^= H->v0; 
 
    H->v2 += H->v1; 
    H->v1 = SIP_ROTL(H->v1, 17); 
    H->v1 ^= H->v2; 
    H->v2 = SIP_ROTL(H->v2, 32); 
  } 
} /* sip_round() */ 
 
static struct siphash * 
sip24_init(struct siphash *H, const struct sipkey *key) { 
  H->v0 = _SIP_ULL(0x736f6d65U, 0x70736575U) ^ key->k[0]; 
  H->v1 = _SIP_ULL(0x646f7261U, 0x6e646f6dU) ^ key->k[1]; 
  H->v2 = _SIP_ULL(0x6c796765U, 0x6e657261U) ^ key->k[0]; 
  H->v3 = _SIP_ULL(0x74656462U, 0x79746573U) ^ key->k[1]; 
 
  H->p = H->buf; 
  H->c = 0; 
 
  return H; 
} /* sip24_init() */ 
 
#define sip_endof(a) (&(a)[sizeof(a) / sizeof *(a)]) 
 
static struct siphash * 
sip24_update(struct siphash *H, const void *src, size_t len) { 
  const unsigned char *p = (const unsigned char *)src, *pe = p + len; 
  uint64_t m; 
 
  do { 
    while (p < pe && H->p < sip_endof(H->buf)) 
      *H->p++ = *p++; 
 
    if (H->p < sip_endof(H->buf)) 
      break; 
 
    m = SIP_U8TO64_LE(H->buf); 
    H->v3 ^= m; 
    sip_round(H, 2); 
    H->v0 ^= m; 
 
    H->p = H->buf; 
    H->c += 8; 
  } while (p < pe); 
 
  return H; 
} /* sip24_update() */ 
 
static uint64_t 
sip24_final(struct siphash *H) { 
  const char left = (char)(H->p - H->buf); 
  uint64_t b = (H->c + left) << 56; 
 
  switch (left) { 
  case 7: 
    b |= (uint64_t)H->buf[6] << 48; 
    /* fall through */ 
  case 6: 
    b |= (uint64_t)H->buf[5] << 40; 
    /* fall through */ 
  case 5: 
    b |= (uint64_t)H->buf[4] << 32; 
    /* fall through */ 
  case 4: 
    b |= (uint64_t)H->buf[3] << 24; 
    /* fall through */ 
  case 3: 
    b |= (uint64_t)H->buf[2] << 16; 
    /* fall through */ 
  case 2: 
    b |= (uint64_t)H->buf[1] << 8; 
    /* fall through */ 
  case 1: 
    b |= (uint64_t)H->buf[0] << 0; 
    /* fall through */ 
  case 0: 
    break; 
  } 
 
  H->v3 ^= b; 
  sip_round(H, 2); 
  H->v0 ^= b; 
  H->v2 ^= 0xff; 
  sip_round(H, 4); 
 
  return H->v0 ^ H->v1 ^ H->v2 ^ H->v3; 
} /* sip24_final() */ 
 
static uint64_t 
siphash24(const void *src, size_t len, const struct sipkey *key) { 
  struct siphash state = SIPHASH_INITIALIZER; 
  return sip24_final(sip24_update(sip24_init(&state, key), src, len)); 
} /* siphash24() */ 
 
/* 
 * SipHash-2-4 output with 
 * k = 00 01 02 ... 
 * and 
 * in = (empty string) 
 * in = 00 (1 byte) 
 * in = 00 01 (2 bytes) 
 * in = 00 01 02 (3 bytes) 
 * ... 
 * in = 00 01 02 ... 3e (63 bytes) 
 */ 
static int 
sip24_valid(void) { 
  /* clang-format off */ 
  static const unsigned char vectors[64][8] = { 
    { 0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72, }, 
    { 0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74, }, 
    { 0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d, }, 
    { 0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85, }, 
    { 0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf, }, 
    { 0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18, }, 
    { 0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb, }, 
    { 0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab, }, 
    { 0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93, }, 
    { 0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e, }, 
    { 0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a, }, 
    { 0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4, }, 
    { 0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75, }, 
    { 0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14, }, 
    { 0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7, }, 
    { 0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1, }, 
    { 0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f, }, 
    { 0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69, }, 
    { 0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b, }, 
    { 0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb, }, 
    { 0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe, }, 
    { 0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0, }, 
    { 0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93, }, 
    { 0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8, }, 
    { 0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8, }, 
    { 0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc, }, 
    { 0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17, }, 
    { 0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f, }, 
    { 0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde, }, 
    { 0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6, }, 
    { 0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad, }, 
    { 0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32, }, 
    { 0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71, }, 
    { 0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7, }, 
    { 0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12, }, 
    { 0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15, }, 
    { 0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31, }, 
    { 0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02, }, 
    { 0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca, }, 
    { 0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a, }, 
    { 0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e, }, 
    { 0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad, }, 
    { 0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18, }, 
    { 0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4, }, 
    { 0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9, }, 
    { 0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9, }, 
    { 0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb, }, 
    { 0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0, }, 
    { 0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6, }, 
    { 0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7, }, 
    { 0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee, }, 
    { 0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1, }, 
    { 0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a, }, 
    { 0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81, }, 
    { 0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f, }, 
    { 0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24, }, 
    { 0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7, }, 
    { 0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea, }, 
    { 0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60, }, 
    { 0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66, }, 
    { 0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c, }, 
    { 0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f, }, 
    { 0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5, }, 
    { 0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95, } 
  }; 
  /* clang-format on */ 
 
  unsigned char in[64]; 
  struct sipkey k; 
  size_t i; 
 
  sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011" 
                "\012\013\014\015\016\017"); 
 
  for (i = 0; i < sizeof in; ++i) { 
    in[i] = (unsigned char)i; 
 
    if (siphash24(in, i, &k) != SIP_U8TO64_LE(vectors[i])) 
      return 0; 
  } 
 
  return 1; 
} /* sip24_valid() */ 
 
#ifdef SIPHASH_MAIN 
 
#  include <stdio.h> 
 
int 
main(void) { 
  const int ok = sip24_valid(); 
 
  if (ok) 
    puts("OK"); 
  else 
    puts("FAIL"); 
 
  return ! ok; 
} /* main() */ 
 
#endif /* SIPHASH_MAIN */ 
 
#endif /* SIPHASH_H */