lib/base32.h

   1 /* base32.h -- Encode binary data using printable characters.
   2    Copyright (C) 2004-2006, 2009-2018 Free Software Foundation, Inc.
   3    Adapted from Simon Josefsson's base64 code by Gijs van Tulder.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef BASE32_H
  19 # define BASE32_H
  20
  21 /* Get size_t. */
  22 # include <stddef.h>
  23
  24 /* Get bool. */
  25 # include <stdbool.h>
  26
  27 /* This uses that the expression (n+(k-1))/k means the smallest
  28    integer >= n/k, i.e., the ceiling of n/k.  */
  29 # define BASE32_LENGTH(inlen) ((((inlen) + 4) / 5) * 8)
  30
  31 struct base32_decode_context
  32 {
  33   unsigned int i;
  34   char buf[8];
  35 };
  36
  37 extern bool isbase32 (char ch) _GL_ATTRIBUTE_CONST;
  38
  39 extern void base32_encode (const char *restrict in, size_t inlen,
  40                            char *restrict out, size_t outlen);
  41
  42 extern size_t base32_encode_alloc (const char *in, size_t inlen, char **out);
  43
  44 extern void base32_decode_ctx_init (struct base32_decode_context *ctx);
  45
  46 extern bool base32_decode_ctx (struct base32_decode_context *ctx,
  47                                const char *restrict in, size_t inlen,
  48                                char *restrict out, size_t *outlen);
  49
  50 extern bool base32_decode_alloc_ctx (struct base32_decode_context *ctx,
  51                                      const char *in, size_t inlen,
  52                                      char **out, size_t *outlen);
  53
  54 #define base32_decode(in, inlen, out, outlen) \
  55         base32_decode_ctx (NULL, in, inlen, out, outlen)
  56
  57 #define base32_decode_alloc(in, inlen, out, outlen) \
  58         base32_decode_alloc_ctx (NULL, in, inlen, out, outlen)
  59
  60 #endif /* BASE32_H */