2 * This file is part of DisOrder
3 * Copyright (C) 2005, 2007 Richard Kettlewell
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 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
20 /** @file lib/base64.c
21 * @brief Support for MIME base64
35 static const char mime_base64_table[] =
36 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
38 /** @brief Convert MIME base64
39 * @param s base64 data
40 * @param nsp Where to store length of converted data
41 * @return Decoded data
43 * See <a href="http://tools.ietf.org/html/rfc2045#section-6.8">RFC
46 char *mime_base64(const char *s, size_t *nsp) {
53 while((c = (unsigned char)*s++)) {
54 if((t = strchr(mime_base64_table, c))) {
55 b[n++] = t - mime_base64_table;
57 dynstr_append(&d, (b[0] << 2) + (b[1] >> 4));
58 dynstr_append(&d, (b[1] << 4) + (b[2] >> 2));
59 dynstr_append(&d, (b[2] << 6) + b[3]);
64 dynstr_append(&d, (b[0] << 2) + (b[1] >> 4));
66 dynstr_append(&d, (b[1] << 4) + (b[2] >> 2));
77 /** @brief Convert a binary string to base64
78 * @param s Bytes to convert
79 * @param ns Number of bytes to convert
80 * @return Encoded data
82 * This function does not attempt to split up lines.
84 * See <a href="http://tools.ietf.org/html/rfc2045#section-6.8">RFC
87 char *mime_to_base64(const uint8_t *s, size_t ns) {
92 /* Input bytes with output bits: AAAAAABB BBBBCCCC CCDDDDDD */
93 /* Output bytes with input bits: 000000 001111 111122 222222 */
94 dynstr_append(d, mime_base64_table[s[0] >> 2]);
95 dynstr_append(d, mime_base64_table[((s[0] & 3) << 4)
97 dynstr_append(d, mime_base64_table[((s[1] & 15) << 2)
99 dynstr_append(d, mime_base64_table[s[2] & 63]);
104 dynstr_append(d, mime_base64_table[s[0] >> 2]);
107 dynstr_append(d, mime_base64_table[(s[0] & 3) << 4]);
108 dynstr_append(d, '=');
109 dynstr_append(d, '=');
112 dynstr_append(d, mime_base64_table[((s[0] & 3) << 4)
114 dynstr_append(d, mime_base64_table[(s[1] & 15) << 2]);
115 dynstr_append(d, '=');