release/src/router/nettle/base16.h

   1 /* base16.h
   2  *
   3  * Hex encoding and decoding, following spki conventions (i.e.
   4  * allowing whitespace between digits).
   5  */
   6
   7 /* nettle, low-level cryptographics library
   8  *
   9  * Copyright (C) 2002 Niels Möller
  10  *
  11  * The nettle library is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU Lesser General Public License as published by
  13  * the Free Software Foundation; either version 2.1 of the License, or (at your
  14  * option) any later version.
  15  *
  16  * The nettle library is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  18  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  19  * License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public License
  22  * along with the nettle library; see the file COPYING.LIB.  If not, write to
  23  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  24  * MA 02111-1301, USA.
  25  */
  26
  27 #ifndef NETTLE_BASE16_H_INCLUDED
  28 #define NETTLE_BASE16_H_INCLUDED
  29
  30 #include "nettle-types.h"
  31
  32 #ifdef __cplusplus
  33 extern "C" {
  34 #endif
  35
  36 /* Name mangling */
  37 #define base16_encode_single nettle_base16_encode_single
  38 #define base16_encode_update nettle_base16_encode_update
  39 #define base16_decode_init nettle_base16_decode_init
  40 #define base16_decode_single nettle_base16_decode_single
  41 #define base16_decode_update nettle_base16_decode_update
  42 #define base16_decode_final nettle_base16_decode_final
  43
  44 /* Base16 encoding */
  45
  46 /* Maximum length of output for base16_encode_update. */
  47 #define BASE16_ENCODE_LENGTH(length) ((length) * 2)
  48
  49 /* Encodes a single byte. Always stores two digits in dst[0] and dst[1]. */
  50 void
  51 base16_encode_single(uint8_t *dst,
  52                      uint8_t src);
  53
  54 /* Always stores BASE16_ENCODE_LENGTH(length) digits in dst. */
  55 void
  56 base16_encode_update(uint8_t *dst,
  57                      unsigned length,
  58                      const uint8_t *src);
  59
  60
  61 /* Base16 decoding */
  62
  63 /* Maximum length of output for base16_decode_update. */
  64 /* We have at most 4 buffered bits, and a total of (length + 1) * 4 bits. */
  65 #define BASE16_DECODE_LENGTH(length) (((length) + 1) / 2)
  66
  67 struct base16_decode_ctx
  68 {
  69   unsigned word;   /* Leftover bits */
  70   unsigned bits;   /* Number buffered bits */
  71 };
  72
  73 void
  74 base16_decode_init(struct base16_decode_ctx *ctx);
  75
  76 /* Decodes a single byte. Returns amount of output (0 or 1), or -1 on
  77  * errors. */
  78 int
  79 base16_decode_single(struct base16_decode_ctx *ctx,
  80                      uint8_t *dst,
  81                      uint8_t src);
  82
  83 /* Returns 1 on success, 0 on error. DST should point to an area of
  84  * size at least BASE16_DECODE_LENGTH(length), and for sanity
  85  * checking, *DST_LENGTH should be initialized to the size of that
  86  * area before the call. *DST_LENGTH is updated to the amount of
  87  * decoded output. */
  88
  89 /* Currently results in an assertion failure if *DST_LENGTH is
  90  * too small. FIXME: Return some error instead? */
  91 int
  92 base16_decode_update(struct base16_decode_ctx *ctx,
  93                      unsigned *dst_length,
  94                      uint8_t *dst,
  95                      unsigned src_length,
  96                      const uint8_t *src);
  97
  98 /* Returns 1 on success. */
  99 int
 100 base16_decode_final(struct base16_decode_ctx *ctx);
 101
 102 #ifdef __cplusplus
 103 }
 104 #endif
 105
 106 #endif /* NETTLE_BASE16_H_INCLUDED */