release/src/router/nettle/write-be32.c

   1 /* write-be32.c */
   2
   3 /* nettle, low-level cryptographics library
   4  *
   5  * Copyright (C) 2001 Niels Möller
   6  *
   7  * The nettle library is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU Lesser General Public License as published by
   9  * the Free Software Foundation; either version 2.1 of the License, or (at your
  10  * option) any later version.
  11  *
  12  * The nettle library is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15  * License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with the nettle library; see the file COPYING.LIB.  If not, write to
  19  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  20  * MA 02111-1301, USA.
  21  */
  22
  23 #if HAVE_CONFIG_H
  24 # include "config.h"
  25 #endif
  26
  27 #include <stdlib.h>
  28
  29 #include "nettle-write.h"
  30
  31 #include "macros.h"
  32
  33 void
  34 _nettle_write_be32(unsigned length, uint8_t *dst,
  35                    uint32_t *src)
  36 {
  37   unsigned i;
  38   unsigned words;
  39   unsigned leftover;
  40
  41   words = length / 4;
  42   leftover = length % 4;
  43
  44   for (i = 0; i < words; i++, dst += 4)
  45     WRITE_UINT32(dst, src[i]);
  46
  47   if (leftover)
  48     {
  49       uint32_t word;
  50       unsigned j = leftover;
  51
  52       word = src[i];
  53
  54       switch (leftover)
  55         {
  56         default:
  57           abort();
  58         case 3:
  59           dst[--j] = (word >> 8) & 0xff;
  60           /* Fall through */
  61         case 2:
  62           dst[--j] = (word >> 16) & 0xff;
  63           /* Fall through */
  64         case 1:
  65           dst[--j] = (word >> 24) & 0xff;
  66         }
  67     }
  68 }