crypto/macros.h

   1 /* macros.h
   2  *
   3  */
   4
   5 /* nettle, low-level cryptographics library
   6  *
   7  * Copyright (C) 2001 Niels Möller
   8  *
   9  * The nettle library is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or (at your
  12  * option) any later version.
  13  *
  14  * The nettle library is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  16  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  17  * License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with the nettle library; see the file COPYING.LIB.  If not, write to
  21  * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  22  * MA 02111-1307, USA.
  23  */
  24
  25 #ifndef NETTLE_MACROS_H_INCLUDED
  26 #define NETTLE_MACROS_H_INCLUDED
  27
  28 /* Reads a 32-bit integer, in network, big-endian, byte order */
  29 #define READ_UINT32(p)                          \
  30 (  (((uint32_t) (p)[0]) << 24)                  \
  31  | (((uint32_t) (p)[1]) << 16)                  \
  32  | (((uint32_t) (p)[2]) << 8)                   \
  33  |  ((uint32_t) (p)[3]))
  34
  35 #define WRITE_UINT32(p, i)                      \
  36 do {                                            \
  37   (p)[0] = ((i) >> 24) & 0xff;                  \
  38   (p)[1] = ((i) >> 16) & 0xff;                  \
  39   (p)[2] = ((i) >> 8) & 0xff;                   \
  40   (p)[3] = (i) & 0xff;                          \
  41 } while(0)
  42
  43 /* Analogous macros, for 24 and 16 bit numbers */
  44 #define READ_UINT24(p)                          \
  45 (  (((uint32_t) (p)[0]) << 16)                  \
  46  | (((uint32_t) (p)[1]) << 8)                   \
  47  |  ((uint32_t) (p)[2]))
  48
  49 #define WRITE_UINT24(p, i)                      \
  50 do {                                            \
  51   (p)[0] = ((i) >> 16) & 0xff;                  \
  52   (p)[1] = ((i) >> 8) & 0xff;                   \
  53   (p)[2] = (i) & 0xff;                          \
  54 } while(0)
  55
  56 #define READ_UINT16(p)                          \
  57 (  (((uint32_t) (p)[0]) << 8)                   \
  58  |  ((uint32_t) (p)[1]))
  59
  60 #define WRITE_UINT16(p, i)                      \
  61 do {                                            \
  62   (p)[0] = ((i) >> 8) & 0xff;                   \
  63   (p)[1] = (i) & 0xff;                          \
  64 } while(0)
  65
  66 /* And the other, little-endian, byteorder */
  67 #define LE_READ_UINT32(p)                       \
  68 (  (((uint32_t) (p)[3]) << 24)                  \
  69  | (((uint32_t) (p)[2]) << 16)                  \
  70  | (((uint32_t) (p)[1]) << 8)                   \
  71  |  ((uint32_t) (p)[0]))
  72
  73 #define LE_WRITE_UINT32(p, i)                   \
  74 do {                                            \
  75   (p)[3] = ((i) >> 24) & 0xff;                  \
  76   (p)[2] = ((i) >> 16) & 0xff;                  \
  77   (p)[1] = ((i) >> 8) & 0xff;                   \
  78   (p)[0] = (i) & 0xff;                          \
  79 } while(0)
  80
  81 /* Macro to make it easier to loop over several blocks. */
  82 #define FOR_BLOCKS(length, dst, src, blocksize) \
  83   assert( !((length) % (blocksize)));           \
  84   for (; (length); ((length) -= (blocksize),    \
  85                   (dst) += (blocksize),         \
  86                   (src) += (blocksize)) )
  87
  88 #endif /* NETTLE_MACROS_H_INCLUDED */