base16dec.c 2.83 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
/* base16dec -- an decoder for base16
 *
 * Copyright (C) 2006, 2012 Jeronimo Pellegrini, Niels Möller
 *  
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with the nettle library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

#if HAVE_CONFIG_H
# include "config.h"
#endif

#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
29
30
31
#ifdef WIN32
#include <fcntl.h>
#endif
32

33
#include "base16.h"
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115

#include "io.h"

#define CHUNK_SIZE 16392

/* The maximum number of bytes generated for each chunk: */
#define DECODED_SIZE BASE16_DECODE_LENGTH(CHUNK_SIZE)


/*
 * Reads base-16 encoded from stdin, writes decoded to stdout.
 */
int
main(int argc UNUSED, char **argv UNUSED)
{
  /* "buffer" will hold the bytes from disk: */
  uint8_t * buffer = xalloc (CHUNK_SIZE);

  /* "result" will hold bytes before output: */
  uint8_t * result = xalloc (DECODED_SIZE);

  /* We need a Base16 context for decoding: */
  struct base16_decode_ctx b16_ctx;

  /* Init the context: */
  base16_decode_init (&b16_ctx);

#ifdef WIN32
  _setmode(1, O_BINARY);
#endif

  for (;;)
    {
      int nbytes; /* Number of bytes read frmo disk at each iteration */
      unsigned decoded_bytes; /* Bytes actually generated at each iteration */

      nbytes = fread(buffer, 1, CHUNK_SIZE, stdin);

      if (nbytes < CHUNK_SIZE && ferror(stdin))
	{
	  werror ("Error reading file: %s\n", strerror(errno));
	  return EXIT_FAILURE;
	}
      
    decoded_bytes = BASE16_DECODE_LENGTH(nbytes);

    /* Decodes one chunk: */
    if (!base16_decode_update(&b16_ctx, &decoded_bytes, result, nbytes, buffer))
      {
	werror ("Error decoding input (not base16?)\n");
	return EXIT_FAILURE;
      }

    if (!write_string (stdout, decoded_bytes, result))
      {
	werror ("Error writing file: %s\n", strerror(errno));
	return EXIT_FAILURE;
      }
    if (nbytes < CHUNK_SIZE)
      {
	/* Check if decoding finalized OK: */
	if (!base16_decode_final(&b16_ctx))
	  {
	    werror("Decoding did not finish properly.\n");
	    return EXIT_FAILURE;
	  }
	break;
      }
    }

  if (fflush (stdout) != 0)
    {
      werror ("Error writing file: %s\n", strerror(errno));
      return EXIT_FAILURE;
    }

  free (buffer);
  free (result);

  return EXIT_SUCCESS;
}