mdw@git.distorted.org.uk Git - mLib/blob - hash/siphash.c

   1 /* -*-c-*-
   2  *
   3  * The SipHash-2-4 message authentication code
   4  *
   5  * (c) 2024 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of the mLib utilities library.
  11  *
  12  * mLib is free software: you can redistribute it and/or modify it under
  13  * the terms of the GNU Library General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or (at
  15  * your option) any later version.
  16  *
  17  * mLib is distributed in the hope that it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
  20  * License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with mLib.  If not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  25  * USA.
  26  */
  27
  28 /*----- Header files ------------------------------------------------------*/
  29
  30 #include "siphash.h"
  31
  32 /*----- Main code ---------------------------------------------------------*/
  33
  34 void siphash_setkey(struct siphash_key *k, const octet *p)
  35   { LOAD64_L_(k->k0, p + 0); LOAD64_L_(k->k1, p + 8); }
  36
  37 void siphash_init(struct siphash *s, const struct siphash_key *k)
  38   { SIPHASH_INIT(s->a, s->b, s->c, s->d, k); s->n = s->msz = 0; }
  39
  40 void siphash_hash(struct siphash *s, const void *p, size_t sz)
  41 {
  42   const octet *q = p;
  43   kludge64 m;
  44   size_t n;
  45
  46   s->msz += sz;
  47   n = SIPHASH_BLKSZ - s->n;
  48   if (sz < n)
  49     { memcpy(s->buf + s->n, q, sz); s->n += sz; return; }
  50
  51   if (s->n) {
  52     memcpy(s->buf + s->n, q, n); q += n; sz -= n;
  53     LOAD64_L_(m, s->buf); SIPHASH_WORD(s->a, s->b, s->c, s->d, m);
  54   }
  55   while (sz >= SIPHASH_BLKSZ) {
  56     LOAD64_L_(m, q); SIPHASH_WORD(s->a, s->b, s->c, s->d, m);
  57     q += SIPHASH_BLKSZ; sz -= SIPHASH_BLKSZ;
  58   }
  59   if (sz) memcpy(s->buf, q, sz);
  60   s->n = sz;
  61 }
  62
  63 kludge64 siphash_done(struct siphash *s)
  64 {
  65   kludge64 z;
  66
  67   SIPHASH_FINAL(s->a, s->b, s->c, s->d, z, s->buf, s->n, s->msz);
  68   return (z);
  69 }
  70
  71 kludge64 siphash(const struct siphash_key *k, const void *p, size_t sz)
  72   { kludge64 z; SIPHASH(k, z, p, sz); return (z); }
  73
  74 /*----- That's all, folks -------------------------------------------------*/