gl/base64.h

   1 /* base64.h -- Encode binary data using printable characters.
   2    Copyright (C) 2004-2006, 2009-2023 Free Software Foundation, Inc.
   3    Written by Simon Josefsson.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    This file 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 Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser 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 idx_t.  */
  22 # include <idx.h>
  23
  24 # ifdef __cplusplus
  25 extern "C" {
  26 # endif
  27
  28 /* This uses that the expression (n+(k-1))/k means the smallest
  29    integer >= n/k, i.e., the ceiling of n/k.  */
  30 # define BASE64_LENGTH(inlen) ((((inlen) + 2) / 3) * 4)
  31
  32 struct base64_decode_context
  33 {
  34   int i;
  35   char buf[4];
  36 };
  37
  38 extern bool isbase64 (char ch) _GL_ATTRIBUTE_CONST;
  39
  40 extern void base64_encode (const char *restrict in, idx_t inlen,
  41                            char *restrict out, idx_t outlen);
  42
  43 extern idx_t base64_encode_alloc (const char *in, idx_t inlen, char **out);
  44
  45 extern void base64_decode_ctx_init (struct base64_decode_context *ctx);
  46
  47 extern bool base64_decode_ctx (struct base64_decode_context *ctx,
  48                                const char *restrict in, idx_t inlen,
  49                                char *restrict out, idx_t *outlen);
  50
  51 extern bool base64_decode_alloc_ctx (struct base64_decode_context *ctx,
  52                                      const char *in, idx_t inlen,
  53                                      char **out, idx_t *outlen);
  54
  55 #define base64_decode(in, inlen, out, outlen) \
  56         base64_decode_ctx (NULL, in, inlen, out, outlen)
  57
  58 #define base64_decode_alloc(in, inlen, out, outlen) \
  59         base64_decode_alloc_ctx (NULL, in, inlen, out, outlen)
  60
  61 # ifdef __cplusplus
  62 }
  63 # endif
  64
  65 #endif /* BASE64_H */