release/src/router/nettle/umac-nh.c

   1 /* umac-nh.c
   2  */
   3
   4 /* nettle, low-level cryptographics library
   5  *
   6  * Copyright (C) 2013 Niels Möller
   7  *
   8  * The nettle library is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 of the License, or (at your
  11  * option) any later version.
  12  *
  13  * The nettle library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  16  * License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with the nettle library; see the file COPYING.LIB.  If not, write to
  20  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  21  * MA 02111-1301, USA.
  22  */
  23
  24 #if HAVE_CONFIG_H
  25 # include "config.h"
  26 #endif
  27
  28 #include <assert.h>
  29
  30 #include "umac.h"
  31 #include "macros.h"
  32
  33 uint64_t
  34 _umac_nh (const uint32_t *key, unsigned length, const uint8_t *msg)
  35 {
  36   uint64_t y;
  37
  38   assert (length > 0);
  39   assert (length <= 1024);
  40   assert (length % 32 == 0);
  41   for (y = 0; length > 0; length -= 32, msg += 32, key += 8)
  42     {
  43       uint32_t a, b;
  44       a = LE_READ_UINT32 (msg)      + key[0];
  45       b = LE_READ_UINT32 (msg + 16) + key[4];
  46       y += (uint64_t) a * b;
  47       a = LE_READ_UINT32 (msg +  4) + key[1];
  48       b = LE_READ_UINT32 (msg + 20) + key[5];
  49       y += (uint64_t) a * b;
  50       a = LE_READ_UINT32 (msg +  8) + key[2];
  51       b = LE_READ_UINT32 (msg + 24) + key[6];
  52       y += (uint64_t) a * b;
  53       a = LE_READ_UINT32 (msg + 12) + key[3];
  54       b = LE_READ_UINT32 (msg + 28) + key[7];
  55       y += (uint64_t) a * b;
  56     }
  57
  58   return y;
  59 }