release/src/router/nettle/sha3.c

   1 /* sha3.c
   2  *
   3  * The sha3 hash function.
   4  */
   5
   6 /* nettle, low-level cryptographics library
   7  *
   8  * Copyright (C) 2012 Niels Möller
   9  *
  10  * The nettle library is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or (at your
  13  * option) any later version.
  14  *
  15  * The nettle library is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  17  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  18  * License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with the nettle library; see the file COPYING.LIB.  If not, write to
  22  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  23  * MA 02111-1301, USA.
  24  */
  25
  26 #if HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #include <assert.h>
  31 #include <string.h>
  32
  33 #include "sha3.h"
  34
  35 #include "macros.h"
  36 #include "memxor.h"
  37
  38 static void
  39 sha3_absorb (struct sha3_state *state, unsigned length, const uint8_t *data)
  40 {
  41   assert ( (length & 7) == 0);
  42 #if WORDS_BIGENDIAN
  43   {
  44     uint64_t *p;
  45     for (p = state->a; length > 0; p++, length -= 8, data += 8)
  46       *p ^= LE_READ_UINT64 (data);
  47   }
  48 #else /* !WORDS_BIGENDIAN */
  49   memxor ((uint8_t *) state->a, data, length);
  50 #endif
  51
  52   sha3_permute (state);
  53 }
  54
  55 unsigned
  56 _sha3_update (struct sha3_state *state,
  57               unsigned block_size, uint8_t *block,
  58               unsigned pos,
  59               unsigned length, const uint8_t *data)
  60 {
  61   if (pos > 0)
  62     {
  63       unsigned left = block_size - pos;
  64       if (length < left)
  65         {
  66           memcpy (block + pos, data, length);
  67           return pos + length;
  68         }
  69       else
  70         {
  71           memcpy (block + pos, data, left);
  72           data += left;
  73           length -= left;
  74           sha3_absorb (state, block_size, block);
  75         }
  76     }
  77   for (; length >= block_size; length -= block_size, data += block_size)
  78     sha3_absorb (state, block_size, data);
  79
  80   memcpy (block, data, length);
  81   return length;
  82 }
  83
  84 void
  85 _sha3_pad (struct sha3_state *state,
  86            unsigned block_size, uint8_t *block, unsigned pos)
  87 {
  88   assert (pos < block_size);
  89   block[pos++] = 1;
  90
  91   memset (block + pos, 0, block_size - pos);
  92   block[block_size - 1] |= 0x80;
  93
  94   sha3_absorb (state, block_size, block);
  95 }