release/src/router/nettle/base16-encode.c

   1 /* base16-encode.c
   2  *
   3  * Hex encoding.
   4  */
   5
   6 /* nettle, low-level cryptographics library
   7  *
   8  * Copyright (C) 2002 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 "base16.h"
  31
  32
  33 static const uint8_t
  34 hex_digits[16] = "0123456789abcdef";
  35
  36 #define DIGIT(x) (hex_digits[(x) & 0xf])
  37
  38 /* Encodes a single byte. Always stores two digits in dst[0] and dst[1]. */
  39 void
  40 base16_encode_single(uint8_t *dst,
  41                      uint8_t src)
  42 {
  43   dst[0] = DIGIT(src/0x10);
  44   dst[1] = DIGIT(src);
  45 }
  46
  47 /* Always stores BASE16_ENCODE_LENGTH(length) digits in dst. */
  48 void
  49 base16_encode_update(uint8_t *dst,
  50                      unsigned length,
  51                      const uint8_t *src)
  52 {
  53   unsigned i;
  54
  55   for (i = 0, dst; i<length; i++, dst += 2)
  56     base16_encode_single(dst, src[i]);
  57 }