lib/base64.h

   1 /* base64.h -- Encode binary data using printable characters.
   2    Copyright (C) 2004-2006, 2009-2019 Free Software Foundation, Inc.
   3    Written by Simon Josefsson.
   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 BASE64_H
  19 # define BASE64_H
  20
  21 /* Get size_t. */
  22 # include <stddef.h>
  23
  24 /* Get bool. */
  25 # include <stdbool.h>
  26
  27 # ifdef __cplusplus
  28 extern "C" {
  29 # endif
  30
  31 /* This uses that the expression (n+(k-1))/k means the smallest
  32    integer >= n/k, i.e., the ceiling of n/k.  */
  33 # define BASE64_LENGTH(inlen) ((((inlen) + 2) / 3) * 4)
  34
  35 struct base64_decode_context
  36 {
  37   unsigned int i;
  38   char buf[4];
  39 };
  40
  41 extern bool isbase64 (char ch) _GL_ATTRIBUTE_CONST;
  42
  43 extern void base64_encode (const char *restrict in, size_t inlen,
  44                            char *restrict out, size_t outlen);
  45
  46 extern size_t base64_encode_alloc (const char *in, size_t inlen, char **out);
  47
  48 extern void base64_decode_ctx_init (struct base64_decode_context *ctx);
  49
  50 extern bool base64_decode_ctx (struct base64_decode_context *ctx,
  51                                const char *restrict in, size_t inlen,
  52                                char *restrict out, size_t *outlen);
  53
  54 extern bool base64_decode_alloc_ctx (struct base64_decode_context *ctx,
  55                                      const char *in, size_t inlen,
  56                                      char **out, size_t *outlen);
  57
  58 #define base64_decode(in, inlen, out, outlen) \
  59         base64_decode_ctx (NULL, in, inlen, out, outlen)
  60
  61 #define base64_decode_alloc(in, inlen, out, outlen) \
  62         base64_decode_alloc_ctx (NULL, in, inlen, out, outlen)
  63
  64 # ifdef __cplusplus
  65 }
  66 # endif
  67
  68 #endif /* BASE64_H */